Preparation of Pb(Zr,Ti)O-3 thin films by soft chemical route

Lead zirconate titanate, Pb(Zr0.3Ti0.7)O-3 (PZT) thin films were prepared with success by the polymeric precursor method. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), Micro-Raman spectroscopy and X-ray diffraction (XRD) were used to investigate the formation of the PZT perovskite phase. X-ray diffraction revealed that the film showed good crystallinity and no presence of secondary phases was identified. This indicates that the PZT thin films were crystallized in a single phase. PZT thin films showed a well-developed dense grain structure with uniform distribution, without the presence of rosette structure. The Raman spectra undoubtedly revealed these thin films in the tetragonal phase. For the thin films annealed at the 500-700 degreesC range, the vibration modes of the oxygen sublattice of the PZT perovskite phase were confirmed by FT-IR. The room temperature dielectric constant and dielectric loss of the PZT films, measured at 1 kHz were 646 and 0.090, respectively, for thin film with 365 nm thickness annealed at 700 degreesC for 2 h. A typical P-E hysteresis loop was observed and the measured values of P-s, P-r and E-c were 68 muC/cm(2), 44 muC/cm(2) and 123 kV/cm, respectively. The leakage current density was about 4.8 x 10(-7) A/cm(2) at 1.5 V. (C) 2003 Elsevier Ltd. All rights reserved.

Differential vascular adaptive response in spontaneously hypertensive and Wistar rats: Role of nitric oxide, and prehypertensive and hypertensive states

Stress-induced vascular adaptive response in SHR was investigated, focusing on the endothelium. Noradrenaline responses were studied in intact and denuded aortas from 6-week-old (prehypertensive) and 14-week-old (hypertensive) SHR and age-matched Wistar rats submitted or not to acute stress (20-min swimming and I-h immobilization 25 min apart), preceded or not by chronic stress (2 sessions 2 days apart of 1-h day immobilization for 5-consecutive days). Stress did not alter the reactivity of denuded aorta. Moreover, no alteration in the EC50 values was observed after stress exposure. In intact aortas, acute stress-induced hyporeactivity to noradrenaline similar between strains at both age. Chronic stress potentiated this adaptive response in 6- and 14-week-old Wistar but not in 6-week-old SHR, and did not alter the reactivity of 14-week-old SHR. Maximum response (g) in intact aortas [6-week-old: Wistar 3.25 +/- 0.12, Wistar/acute 1.95 +/- 0.12*, Wistar/chronic 1.36 +/- 0.21*(+), SHR 1.75 +/- 0.11, SHR/acute 0.88 +/- 0.08*, SHR/chronic 0.85 +/- 0.05*; 14-week-old: Wistar 3.83 +/- 0.13, Wistar/acute 2.72 +/- 0.13*, Wistar/chronic 1.91 +/- 0.19*', SHR 4.03 +/- 0.17, SHR/acute 2.26 +/- 0.12*, SHR/chronic 4.10 +/- 0.23; inside the same strain: *P < 0.05 relate to non-stressed rat, (+)P < 0.05 related to acute stressed rat; n = 6-18]. Independent of age and strain, L-NAME and endothelium removal abolished the stress-induced aorta hyporeactivity. Conclusion: the vascular adaptive response to stress is impaired in SHR, independently of the hypertensive state. Moreover, this vascular adaptive response is characterized by endothelial nitric oxide-system hyperactivity in both strains. (c) 2006 Elsevier B.V. All rights reserved.

Análise não destrutiva de pigmentos fotossintéticos em folhas de gergelim

The study aimed to relate the photosynthetic pigments, which were extracted in a laboratory and the readings were obtained by the portable chlorophyll meter ClorofiLOG 1030, by using mathematical models in sesame leaves. This work was conducted in December 2010, at Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Cotton, where feaf discs were removed to measure chlorophyll indexes through the portable chlorophyll meter. The same leaf discs were subjected to extraction of photosynthetic pigments, by using 5 mL dimethyl sulfoxide (DMSO), and were kept in a water bath at 70 degrees C for 30 min. Afterwards, an aliquot of 3 mL was removed to be read in a spectrophotometer at wavelengths of 470, 646 and 663 nm. Based on analytical results, mathematical models were adjusted by using the chlorophyll index to predict the levels of chlorophyll a, b, and total, and of carotenoids and their relationships. The study concluded that the portable chlorophyll meter ClorofiLOG 1030 can be used to estimate the concentration of photosynthetic pigments in sesame leaves with high precision, besides saving resources and time.

Fungus-growing ants (Hymenoptera: Formicidae) on Santa Catarina Island, Brazil: patterns of occurrence

A taxonomic survey on fungus-growing ants (Attini) was made at 14 beaches on Santa Catarina Island (SC), Brazil. The samplings were manual, in soil or litterfall, in the following habitats: sandy beach, herbaceous vegetation and shrubby vegetation. From 12 species of Attini (ten of Acromyrmex Mayr and two of Cyphomyrmex Mayr), the most frequent were Cyphomyrmex morschi Emery and Acromyrmex crassispinus Forel, collected, respectively, on eight and ten of the monitored beaches. Altogether, Sorensen's similarity coefficients were high (range: 0.59-0.80), in spite of the lower numbers of ant species on sandy beaches.

A fast electric load forecasting using neural networks

The objective of this work is the development of a methodology for electric load forecasting based on a neural network. Here, it is used Backpropagation algorithm with an adaptive process based on fuzzy logic. This methodology results in fast training, when compared to the conventional formulation of Backpropagation algorithm. Results are presented using data from a Brazilian Electric Company and the performance is very good for the proposal objective.

Modelagem gravimétrica da Bacia de Taubaté-vale do Rio Paraíba do Sul, leste do estado de São Paulo

This paper presents the gravity survey refinement of the Paraíba do Sul river valley, east region of São Paulo state, by acquisition of 646 gravity stations. Further than the traditional Free-Air and Bouguer corrections, it was necessary to apply the Terrain Correction due the proximity of the Mantiqueira and Mar mountain ranges. An enhanced understanding of Taubaté Basin structural framework was the main objetive of this work. As result, we present the Bouguer Gravity Map of the east region of São Paulo State and the Residual Bouguer Gravity Map generated by Upward Continuation and High-pass filtering. The 2D Gravity Modeling was applied in 4 sections, using bi-dimensional models for the bodies that produced the anomalies (Talwani Method). After integrating the gravity data with the interpretation of 11 seismic sections, it was possible to delineate the Taubate Basin structural framework, which shows an utmost sedimentary thickness of 800 m in the depocenters. It was also interpreted an ultramaphic alkaline plug in the subsurface of Caçapava city.

Peso de abate de machos não-castrados para produção do bovino jovem. 2. Peso, Idade e caracteristicas da carcaça

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Yield and fruit size distribution of processing tomato cultivars

The productivity and fruit size distribution of 28 processing tomato cultivars were analyzed to determine the ones with potential for fresh market. The experiment was done in Jaboticabal-SP, Brazil (21o15'22'' South, 48o18'58'' West, altitude 595 m), in a Haplorthox soil, from June to December. The cultivars H 7155, Hypeel 108, Andino, U 573, H 9036, Ipa 6, H 9494, AG 33, Yuba, RPT 1294, AG 72, Peelmech, Curicó, Hypeel 45, RPT 1478, H 9492, H 9498, H 2710, Hitech 45, Halley, Botu 13, H 9553, U 646, NK 1570, AG 45, RPT 1095, RPT 1570 and PSX 37511 were evaluated. The experimental design was randomized blocks, with four repetitions, and five plants per experimental unit. Fruits harvested from each experimental unit were counted, classified by transversal diameter (large, medium, small, very small and cull) and then weighed. Cultivars AG 72, H 9498, Hypeel 45, RPT 1095 and Curicó yielded more than 70 fruits per plant, on average. The total production per plant of cultivars AG 72, H 9498, Hypeel 45, H 7155, Hypeel 108, Halley, Hitech, RPT 1095, H 9494, H 9036 and Curicó was greater than 4 kg. Considering the weight of large and medium fruits, categories which are important for fresh market, the cultivars H 2710, Botu 13, U 573, Hypeel 45, Yuba, RPT 1294 and Ipa 6 presented values above 50% for production.

Total and harvest-date yield of processing tomato cultivars

The productivity of 28 tomato cultivars was evaluated over three stages of harvest. The study was carried out during from June to December of 1999 in an open field at the experimental area of the Section of Olericulture and Aromatic Medicinal Plants, Department of Crop Production at FCAV-UNESP, Jaboticabal, SP, Brazil. The cultivars studied were H 7155, Hypeel, Andino, U 573, H 9036, IPA 6, H 9494, AG 33, Yuba, RPT 1294, AG 72, Pelmeech, Curico, Hypeel 45, RPT 1478, H 9492, H 9498, H 2710, Hitech 45, Halley, Botu 13, H 9553, U 646, NK 1570, AG 45, RPT 1095, RPT 1570, and PSX 37511. The experimental design was a randomized block design with four repetitions, with five plants per plot. Productivity was evaluated at three stages of harvest at 119, 149 and 179 days after seeding. There were no significant differences among the cultivars at the first harvest (119 days). The majority of the cultivars produced their highest yield at the second harvest; the most productive cultivars were Curicó and AG 72, which yielded 4.69 and 4.67 kg/plant, respectively, although they did not differ statistically from the cultivars Hypeel 45 (4.35 kg/plant) and H 9498 (4.16 kg/plant). Yields of the cultivars Andino and H 9494 were evenly distributed between the second and third harvests. At the third harvest, cultivar IPA 6 had the highest yield (2.9 kg/plant) and was statistically different from all other cultivars except H 9036 (2.34 kg). These two cultivars had the most delayed and concentrated maturity, making them suitable for mechanical harvesting, although at a later time. Cultivar AG 72 had the greatest total yield (5.76 kg/plant), but it was not statistically different from cultivars Hypeel 45 (5.43 kg), Curico (4.17 kg), H 9498 (4.83 kg), H 7155 (4.58 kg) and Halley (4.55 kg). All of the cultivars, with the exception of cultivars H 9036, IPA 6, Andino and H 9494 showed in the second harvest concentrated maturity, making it suitable for mechanical harvesting.

Physical-chemical characterization of processing tomato fruit

Fruit of 28 tomato cultivars for industrial processing were characterized to identify cultivars with potential for in natura consumption. The experiment was carried out in Jaboticabal-SP, Brazil (21o15'22'' South, 48o18'58'' West, altitude 595 m), on a Haplorthox soil during June-December. The cultivars used in this study were: H 7155, Hypeel 108, Andino, U 573, H 9036, Ipa 6, H 9494, AG 33, Yuba, RPT 1294, AG 72, Peelmech, Curicó, Hypeel 45, RPT 1478, H 9492, H 9498, H 2710, Hitech 45, Halley, Botu 13, H 9553, U 646, NK 1570, AG 45, RPT 1095, RPT 1570 and PSX 37511. The experimental design was randomized blocks, replicated four times. Ten fruits per plot were analyzed, evaluating the following characteristics: shape (oblong or round); length and diameter (mm); external and internal coloration; presence of fissures; number of loci; pulp thickness (mm); soluble solids content (Brix) and total acidity. Only cultivars Hypeel 108, AG 72, NK 1570, RPT 1570 had oblong fruit. Cultivars which had pulp thicker than 5.5 mm, a characteristic which is directly related to fruit yield for industrial purposes were: Ipa 6, Andino, U 646, H 9553, RPT 1294 and Hypeel 108. Cultivars Ipa 6 and Andino also presented elevated values for length, diameter and pulp thickness, indicating them as quality material for industry or, alternatively, for in natura market. Among the cultivars which presented better values for acidity (higher or equal to 0.3 g citric acid 100 g-1) were RPT 1095, AG 45, H 9553 and Hypeel 45.

Histochemical characterization and secretory activity of the hypopharyngeal glands in the primitive social wasp Polistes versicolor (Hymenoptera: Vespidae)

Using histochemical techniques, the present work describes the basic histochemical characteristics of the secretion in hypopharyngeal glands of Polistes versicolor (Olivier) and estimates the secretory activity in specimens of different ages. The secretory activity was determined by glandular cell diameter and by the amount of secretion present in the glands. The results did not reveal a relationship between these parameters and the age of the wasps, not allowing us to determine the development cycle of these glands throughout the wasps' life. Also, a relationship between glandular cell diameter and amount of secretion present in the glands was not observed.

Características reológicas e sensoriais de bebidas lácteas funcionais

This research studied the effects of the independent variables whey protein concentrate - WPC (3.0; 3.5; 4.0%), skimmed milk powder - SMP (4.0; 5.0; 6.0%), and isolated soy protein - IPS (1.5; 2.0; 2.5%) on the rheological and sensorial characteristics of functional dairy beverages. In all tests 7% of sucrose was added to the ingredients. The rheological parameters were obtained in duplicate at the temperature of 10° C using a cone and plate rheometer, and fitted to the Power law model. The samples revealed a non-Newtonian fluid behavior both in the upward and downward curves, typical of a tixotropic fluid. The dairy beverages were submitted to a sensory analysis by a group of fifty untrained tasters who used a hedonic scale of nine points, the extremes being 1 - disliked extremely and 9 - liked extremely, in order to evaluate the following parameters: general acceptability; appearance and color; consistency; taste and aroma. The dairy beverage produced with 3% WPC, 6% SMP and 1.5% IPS, (treatment 3), was the one that obtained the best average score for those attributes and was preferred by the tasters. The variables SMP and IPS and the interaction between WPC and SMP presented a positive effect on the sensory consistency attributes: the higher amount of those ingredients in the formula the more the tasters liked the consistency.

Sintering temperature influence on microwave dielectric properties of TiO2-ZrO2 ceramics

Dielectric ceramics have been widely investigated and used for microwave applications such as resonators and filters. The present study deals with the influence of sintering temperature on microwave dielectric properties of TiO2 ceramics with 10, 20, and 30 wt% ZrO2. Three compositions have been developed through mixing procedures and then tested for each sintering temperature: 1500 and 1400°C. X-ray diffraction and scanning electron microscopy are carried out aiming to explain the ceramic behavior of each sample. The dielectric constants of different ceramics for both temperatures varied from 85.4 to 62.6, while their quality factor due to dielectric losses varied from 3110 to 1630. The Q decrease is attributed to the non uniform grain growth and to the obtained crystalline phases. The best microwave parameters were obtained for the ceramics sintered at 1400°C, which can be applied in microwave circuits as dielectric resonators. © (2010) Trans Tech Publications.

Mechanical properties of vulcanized natural rubber nanocomposites containing functional ceramic nanoparticles

Rubber nanocomposites containing different concentrations of ferroelectric and paramagnetic nanoparticles were fabricated. Nanostructures of ferroelectric potassium strontium niobate and paramagnetic nickel-zinc ferrite were synthesized using a modified polyol method. The nanoparticle characterization was carried out by transmission electron microscopy and X-ray diffraction, showing that the materials were produced with nanometer dimensions, specific crystallinity and microstrain. Mechanical tests such as hardness type Shore A, stress-strain and compression resistance were performed. They showed that increasing the concentration of nanoparticles enhance the rigidity of vulcanized films of natural rubber and this change is more pronounce for the nanocomposites formed with ferrite nanoparticles, likely due to the effect of its morphological and surface properties. © 2013 by American Scientific Publishers.