Effect of in concentration in the starting solution on the structural and electrical properties of ZnO films prepared by the pyrosol process at 450°C

Undoped and indium-doped Zinc oxide (ZnO) solid films were deposited by the pyrosol process at 450°C on glass substrates from solutions where In/Zn ratio was 2, 5, and 10 at.%. Electrical measurements performed at room temperature show that the addition of indium changes the resistance of the films. The resistivities of doped films are less than non-doped ZnO films by one to two orders of magnitude depending on the dopant concentration in the solution. Preferential orientation of the films with the c-axis perpendicular to the substrate was detected by X-ray diffraction and polarized extended X-ray absorption fine structures measurements at the Zn K edge. This orientation depends on the indium concentration in the starting solution. The most textured films were obtained for solutions where In/Zn ratio was 2 and 5 at.%. When In/Zn = 10 at.%, the films had a nearly random orientation of crystallites. Evidence of the incorporation of indium in the ZnO lattice was obtained from extended X-ray absorption fine structures at the In and Zn K edges. The structural analysis of the least resistive film (Zn/In = 5 at.%) shows that In substitutes Zn in the wurtzite structure. © 2000 Elsevier Science B.V. All rights reserved.

Growth of Dendrobium nobile Lindl. as related with nutrient concentration in the growing media

Dendrobium nobile orchids were grown for three years in different substrates (tree fern fiber, blocks of pressed coconut bark, bark of Eucalyptus grandis, mixtures with coconut bark blocks and eucalyptus bark and mixtures with the latter materials and charcoal. Plant growth increased with higher concentrations of S (up to 1.6 g/kg), Cu (up to 46 mg/kg) and Zn (up to 147 mg/kg), and decreased with higher concentrations of Ca (up to 13.2 g/kg), Mg (up to 6.6 g/kg) and B (up to 19 mg/kg). High Mo (up to 5.3 mg/kg) caused a more intense loss of leaves after planting. Relations between nutrient concentrations also affected plant growth. With exception of eucalyptus bark, all growing media under study were suitable for plant growth.

One-dimensional analytical model for oxide thin film growth on Ti metal layers during laser heating in air

This paper presents the theoretical and experimental results for oxide thin film growth on titanium films previously deposited over glass substrate. Ti films of thickness 0.1 μm were heated by Nd:YAG laser pulses in air. The oxide tracks were created by moving the samples with a constant speed of 2 mm/s, under the laser action. The micro-topographic analysis of the tracks was performed by a microprofiler. The results taken along a straight line perpendicular to the track axis revealed a Gaussian profile that closely matches the laser's spatial mode profile, indicating the effectiveness of the surface temperature gradient on the film's growth process. The sample's micro-Raman spectra showed two strong bands at 447 and 612 cm -1 associated with the TiO 2 structure. This is a strong indication that thermo-oxidation reactions took place at the Ti film surface that reached an estimated temperature of 1160 K just due to the action of the first pulse. The results obtained from the numerical integration of the analytical equation which describes the oxidation rate (Wagner equation) are in agreement with the experimental data for film thickness in the high laser intensity region. This shows the partial accuracy of the one-dimensional model adopted for describing the film growth rate. © 2001 Elsevier Science B.V.

Analysis of fluoride concentration in mother's milk substitutes

The aim of the present study was to determine the fluoride concentration in some brands of mother's milk substitutes and evaluate the possibility of developing dental fluorosis by consuming these products. The products, all powdered, were divided into 3 groups: infant formulae (group I, n = 7), milk-based (group M, n = 8) and soy-based (group 8, n = 3). Samples from 3 cans of different batches of each brand were reconstituted in deionized water and analyzed using the specific electrode method, after hexamethyldisiloxane (HMDS) facilitated diffusion. The fluoride content (mg F/L) of the products ranged from 0.044 to 0.326 (I), 0.014 to 0.045 (M) and 0.253 to 0.702 (S). There was significant difference in the fluoride content of cans from distinct batches (p < 0.05) in most of the brands. The reconstitution of all products in water with optimal fluoride concentration for consumption during the mineralization phase of the primary teeth could result in daily fluoride intake above 0.07 mg F/kg body weight/day. Therefore, the consumption of these products, especially when reconstituted with optimally fluoridated water, could increase the risk of developing dental fluorosis.

Heterogeneous photocatalytic treatment of organic dyes in air and aqueous media

This review focuses on the heterogeneous photocatalytic treatment of organic dyes in air and water. Representative studies spanning approximately three decades are included in this review. These studies have mostly used titanium dioxide (TiO2) as the inorganic semiconductor photocatalyst of choice for decolorizing and decomposing the organic dye to mineralized products. Other semiconductors such as ZnO, CdS, WO3, and Fe2O3 have also been used, albeit to a much smaller extent. The topics covered include historical aspects, dark adsorption of the dye on the semiconductor surface and its role in the subsequent photoreaction, semiconductor preparation details, photoreactor configurations, photooxidation kinetics/mechanisms and comparison with other Advanced Oxidation Processes (e.g., UV/H2O2, ozonation, UV/O3, Fenton and photo-Fenton reactions), visible light-induced dye decomposition by sensitization mechanism, reaction intermediates and toxicity issues, and real-world process scenarios. © 2008 Elsevier B.V. All rights reserved.

Citizens' participation and enhancing their active involvement in air pollution control in Latin America

Includes bibliography

Effect of nozzle angle and air-jet parameters in air-assisted sprayer on biological effect of soybean asian rust chemical protection

Aiming at improving the efficiency control of Phakopsora pachyrhizi, this research evaluated different application techniques, using spray deposits and yield parameters of soybean crop. Two experiments were carried out in the experimental area of FCA/UNESP - Botucatu, SP, Brazil, in the soybean crop, Conquista variety, in the 2006/2007 season. The first experiment was arranged in random blocks with eight treatments and four replications. The treatments were conducted in factorial arrangement 4×2 (four air levels 0, 9, 11 and 29 km/h combined at two nozzle angles 0 and 30°) using AXI 110015 nozzles. Ten plants on each plot were selected for sampling spray deposits. Artificial targets were fixed on plants, two in the top and another two in the bottom part of plants (abaxial and adaxial leaf surface each one). For deposit evaluations, a cupric tracer was used and the amount of deposits was determined by a spectrophotometer. The second experiment was carried out in the same place and the treatments were of the same arrangement as the previous experiment, including control treatment (untreated plants). The spraying with triazole fungicide was realized in R2 and R5.2 growth stages of soybean with 142 l/ha spray volume. The nozzle angled of 30° combined with maximum air speed promoted the highest spray deposits on the soybean crop and influenced positively the control of the soybean Asian rust as well in the productivity of this crop.

Responses of blood lactate concentration in aerobic and anaerobic training protocols at different swimming exercise intensities in rats

A swimming periodized experimental training model in rats in which different training protocols (TP) were classified in aerobic (A) and anaerobic (AN) intensity levels. The purpose of the present study was to verify if the classification of the TP used in the periodized training experimental model presented the blood lactate concentration [La] response adequate to the aerobic and anaerobic intensities levels. Twenty three male Wistar rats were divided into three groups. Two groups of swimming training (continuous, CT, n = 7, and periodized training, PET, n = 7) rats were evaluated during 5 weeks in eight different TP (TP-1 to TP-8) through the analysis of the [La] response. The third group was the sedentary control (SC, n = 9). The TP were classified in five intensity levels, three aerobic (A-1, A-2, A-3) and two anaerobic (AN-1, AN-2). Analysis of variance (ANOVA one-way, P<0.05) indicated significant differences in the [La] among the TP and among the five intensity levels. All TP of the A-2 and A-3 intensity levels differed from the A-1 and AN-1. The A-1 and AN-1 also differed among them. These findings demonstrate that the TP were classified properly at different levels of aerobic and anaerobic intensities, as based on the [La] response in a way similar to that of high performance swimming with humans. The results offer new perspectives for the study of exercise training in swimming rats at different levels intensity for performance or for health.

Fluoride concentration in public water supply: 72 months of analysis

Known as one of the ten most important advances on Public Health in the 20th century, fluoridation of public water supply is a measure of wide population coverage, which is effective on caries control. The city of Araçatuba, in the Northwest region of the São Paulo state, Brazil, started public water supply fluoridation in 1972 and, based on the average annual highest temperature, has kept the fluoride concentration between 0.6 to 0.8 mgF/L. The purpose of this study was to analyze monthly the fluoride concentration in public water supply in the city of Araçatuba during 72 months. Water samples were collected monthly on weekdays, directly from the water distribution network, on pre-established locations and analyzed in duplicate between November 2004 and October 2010 at the Research Laboratory of the Nucleus for Public Health (NEPESCO) of the Public Health Graduate Program from Araçatuba Dental School/UNESP, Brazil, using an fluoride-specific electrode connected to an ion analyzer. From the total of samples (n=591), 67.2% (n=397) presented fluoride concentration between 0.6 and 0.8 mgF/L; 20.6% (n=122) below 0.6 mgF/L; 11.5% (n=68) between 0.8 and 1.2 mgF/L and 0.7% (n=4) above 1.2 mgF/L. Most samples showed fluoride levels within the recommended parameters. Minimal variation was observed among the analyzed collection locations, showing that the city has been able to control the fluoride levels in the public water supply and reinforcing the importance of surveillance and constant monitoring to assure the quality of the water delivered to the population.

Comparison of different methods of measuring albumin concentration in ring-necked pheasants

The purpose of this study was to compare albumin concentrations in ring-necked pheasants (Phasianus colchicus) using two different dye-binding methods: the bromocresol green (BCG) and bromocresol purple (BCP). High positive correlation was observed for albumin in BCG and BCP methods. Compared to BCP, the BCG-binding method yielded significantly higher (p < 0. 0001) albumin values for adult female ring-necked pheasants. © 2012 Springer-Verlag London Limited.

Bank consolidation and credit concentration in Brazil (1995-2004)

Includes bibliography

Urbanización, el crecimiento urbano y la concentración en el proceso de asentamiento en América Latina: una visión general = Urbanization, urban growth and settlement concentration in Latin America: a general overview

Incluye Bibliografía

The systematic significance of floral morphology, nectaries, and nectar concentration in epiphytic cacti of tribes Hylocereeae and Rhipsalideae (Cactaceae)

A long-standing interest in cactus taxonomy has existed since the Linnaean generation, but an appreciation of the reproductive biology of cacti started early in the 1900s. Numerous studies indicate that plant reproductive traits provide valuable systematic information. Despite the extensive reproductive versatility and specializations in breeding systems coupled with the striking floral shapes, the reproductive biology of the Cactaceae has been investigated in approximately 10% of its species. Hence, the systematic value of architectural design and organization of internal floral parts has remained virtually unexplored in the family. This study represents the most extensive survey of flower and nectary morphology in the Cactaceae focusing on tribes Hylocereeae and Rhipsalideae (subfamily Cactoideae). Our objectives were (1) to conduct comparative morphological analyses of flowers and floral nectaries and (2) to compare nectar solute concentration in these two tribes consisting of holo- and semi-epiphytic species. Flower morphology, nectary types, and sugar concentration of nectar have strong taxonomic implications at the tribal, generic and specific levels. Foremost, three types of nectaries were found, namely chamber nectary (with the open and diffuse subtypes), furrow nectary (including the holder nectary subtype), and annular nectary. All Hylocereeae species possess chamber nectaries, in which the nectarial tissue has both trichomes and stomata. The Rhipsalideae are distinguished by two kinds of floral nectaries: furrow and annular, both nectary types with stomata only. The annular nectary type characterizes the genus Rhipsalis. Nectar concentration is another significant taxonomic indicator separating the Hylocereeae and Rhipsalideae and establishing trends linked to nectar sugar concentration and amount of nectar production in relation to flower size. There is an inverse relationship between flower size and amount of nectar production in the smaller Rhipsalideae flowers, in which nectar concentration is more than two-fold higher despite the smaller volume of nectar produced when compared to the large Hylocereeae flowers. Variability of nectary morphology and nectar concentration was also evaluated as potential synapomorphic characters in recent phylogenies of these tribes. In conclusion, our data provide strong evidence of the systematic value of floral nectaries and nectar sugar concentration in the Cactaceae, particularly at different taxonomic levels in the Hylocereeae and Rhipsalideae. © 2013 Perspectives in Plant Ecology, Evolution and Systematics.

Concentration in liner shipping: its causes and impacts for ports and shipping services in developing regions

Includes bibliography

Concentration in liner shipping

Containerization, telecommunication, globalization and privatization are among the most important recent trends that have affected shipping. Concentration is another trend which is expected to have a major impact. This refers to the increasing control in the hands of a small number of companies who hold an increasing market share. Although at first this process may be associated with dominant positions and abuse of monopoly power, in reality, the advantages for the economies of Latin America and the Caribbean should by far outweigh the disadvantages. This edition of the FAL Bulletin presents some of the findings of a recent study prepared by the ECLAC Transport Unit, entitled, Concentration in liner shipping - its causes and impacts for ports and shipping services in developing regions, LC/G.2027 , August 1998.