Flow cell within an LED: a proposal for an optical absorption detector

Droplets formed at the tip of a tube under the same conditions possess extreme uniformity of form, volume and weight. These properties of liquid drop formation have been known for a long time and consequently many applications for the drop have been found in instrumentation and chemical analysis methods. In the present paper, we report on the analytical use of a dynamic LED-based flow-through optical absorption detector with optical path length controlled by continuous dropping of a solution. This arrangement consists of a flow cell built within a high-intensity red LED (lambda (max)=630 nm). The feasibility of the detector is demonstrated by colorimetric determination of methylene blue, and ammonium by Berthelot's reaction, in a flow-injection system. For ammonium, the reaction forms a blue dye (indophenol) with a maximum absorption at 630-650 nm. The detection limit, considered as 3 times the signal of the blank, is better than 125 mu g l(-1). The small flow cell represents a good combination of optical path length, low volume and fast washout. This detector can be used advantageously in automated methods and can represent a solution to problems of optical detection involving gas bubbles and precipitation of particles in turbidimetric applications.

Relationship between Crystal Shape, Photoluminescence, and Local Structure in SrTiO3 Synthesized by Microwave-Assisted Hydrothermal Method

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Implicações da agregação espacial de parasitas para a dinâmica populacional na interação hospedeiro-parasita

Some aspects of the widely observed over-dispersed pattern of the distribution of parasites within the host population are examined. It has been established in the parasitological literature that most hosts usually harbour few parasites, while only few hosts harbour a large proportion of the parasite population. Factors that may influence the pattern of distribution of parasites, the relation between the level of parasite aggregation and the prevalence of infection, and changes in this level of aggregation as a function of host age are analysed. Factors which determine the diversity of species in parasite communities are presented, and aspects of exploitative and interference competition among parasites and their relations with biological control procedures are also considered. Attention is also focused on the regulatory and destabilizing processes influencing the dynamic behaviour of host-parasite population interactions.

Determinação de cetamina em plasma por HPLC: Aplicação em um estudo de farmacocinética de associação medicamentosa em cães

A S(+) cetamina é um fármaco amplamente utilizado na medicina para induzir anestesia e a associação com midazolam é empregada para minimizar seus efeitos adversos. Associações medicamentosas podem resultar em interações farmacocinéticas e a disponibilidade de métodos bioanalíticos para a determinação da cetamina em plasma constitui ferramenta útil para a avaliação do perfil cinético do fármaco administrado isoladamente ou em associação. O presente estudo teve como objetivo o desenvolvimento e validação de um método analítico para determinação da cetamina em plasma por cromatografia líquida de alta eficiência (HPLC) e a investigação do perfil farmacocinético da cetamina em quatro cães hígidos da raça Beagle. A S(+) cetamina (10mg/kg) foi administrada pela veia cefálica em dose única isoladamente (protocolo I) ou associada ao midazolam (0.2mg/kg) (protocolo II) em estudo cruzado com intervalo de uma semana para washout. Amostras seriadas de sangue foram coletadas no intervalo de oito horas e analisadas por HPLC para a avaliação do perfil farmacocinético utilizando modelo bicompartimental. O método bioanalítico apresentou limites de confiança aceitáveis para sua aplicação em estudos de farmacocinética e os parâmetros área sob a curva (ASC0-8), volume de distribuição (Vd), clearance total (Clt), meia vida de eliminação (t/12 ß), constante de eliminação (ß), meia vida de distribuição (t1/2α) e constante de distribuição (α) não mostraram diferenças estatísticas significativas entre os grupos (p < 0.05, Wilcoxon). Os resultados obtidos sugerem que a redução dos efeitos colaterais da cetamina decorrente do uso da associação cetamina-midazolam não está relacionada a alterações no perfil farmacocinético da cetamina.

Tree species composition and environmental relationships in a Neotropical swamp forest in Southeastern Brazil

We examined the relationships between topography, soil properties and tree species composition in a Neotropical swamp forest in southeastern Brazil. Plots were sampled in the forest, encompassing three different soil ground water regimes along the topographical declivity. All non-climbing plant individuals with trunk height >1.3 m were sampled. A canonical correspondence analysis-CCA-of the species-environmental relationships grouped tree species according to drainage and chemical soil conditions. A total of 86 species were found, being 77 species in the inferior, 40 species in the intermediate and 35 species in the superior topographic section. Some species were among the 10 most abundant ones, both in the overall sampled area and in each topographical section, with alternation events occurring only with their abundance position. However, substantial differences in floristic composition between sections were detected in a fine spatial scale, due to higher number of species, diversity index (H′) and species unique (exclusives) in the inferior topographic section. These higher values can be attributed to its higher spatial heterogeneity that included better drained and seasonally waterlogged soils, higher soil fertility and lower acidity. The increase of the soil water saturation and the uniform conditions derived from the superficial water layer has led to a lower number of species and an increase on the palm trees abundance in the intermediate and superior sections. Our results showed that at a small spatial scale niche differentiation must be an important factor related to the increase of the local diversity. The wide distribution of the most abundant species in the studied area and the increase of local diversity corroborate the pattern of distribution of species in larger scales of swamp forests, in which the most abundant species repeat themselves in high densities in different remnants. However, the floristic composition of each remnant is strongly variable, contributing to the increase of regional diversity. © 2008 Springer Science+Business Media B.V.

WEDGE - ferramenta on-line de gerenciamento, análise e otimização de processos

This article summarizes the implementation of an online process management, analysis, and optimization tool at Lwarcel Celulose e Papel, within the PIMS and MES philosophy, for process indicator implementation, understanding of variables, and their cause-effect relationship in the process, as well as the achievement of operational benchmarking. The process analysis, by means of statistical tools, allied to mathematical modeling algorithms used in Wedge, makes it possible to identify the relevant information for process and quality improvement with regard to efficiency, equipment maintenance, productivity, and uniformity of the end product quality, reduction of unwanted shutdowns, and quicker resolution of process problems.

Desempenho de gotejadores com uso de esgoto doméstico tratado

This paper aimed to determine the flow rate of drippers, their flow rate-pressure curve, their equation, their flow rate variation coefficient (VCq), as well as to evaluate the uniformity of water application of the Netafim drip pipe, Tiran 17 model, used for irrigation with domestic wastewater from treated household drain. After 1000 working hours, the blockage of some drippers decreased the uniformity of water application from 98% to lower than 60% and increased the flow variation coefficient to values higher than 0.29.

Comparação entre hipertensão autoreferida e pressão arterial casual e presença de fatores de risco em funcionários da saúde Bauru e Jaú

Model: Prevalence study. Objectives: To evaluate the presence of self-reported hypertension to compare with blood pressure measurements. Besides, this work investigated health information level of workers and if the job position has any influence on blood pressure (BP). Methods: This study evaluated 349 health workers (44±10 years old) from Bauru and Jau cities, who answered some questions about history of health condition, use of medicines, past surgeries as well as social, scholar and physical conditions and had their blood pressure measured. Each subject selfreported as normotensive or hypertensive. Values of systolic ≥ 140 mmHg and/or diastolic PA ≥ 90 mmHg were considered elevated. Among the health workers evaluated, 198 were submitted to anthropometric and biochemical evaluations. Values are presented as means ± SD and frequency of distribution. It was used T-student test (p<0.05). Results: From all workers evaluated only 16% self-reported as hypertensive, which 56% presented high BP, however 91% used to take antihypertensive medicines. Among the 84% who self-reported as normotensive, 24% presented high BP and 8% used to take medicines. Although most of the employees of each section self-reported as normotensive, more than a half presented high BP and which was more common in the health's section (76.3%). Conclusion: These results suggest that besides the majority of the employees self-reported as normotensive, an elevated number of health workers presented high blood pressure and used to take medicines inappropriately, which indicates that they did not have enough knowledge about their health. Furthermore, it was observed that Health Section presented the higher blood pressure values.

Estimativa de alguns parâmetros de transporte de contaminantes para solos Brasileiros

This paper introduces an indirect estimate for the coefficients of distribution, hydrodynamic dispersion and retardation for contaminants commonly encountered in sanitary landfills and their liners, such as Cu2+ and K+; this estimate is based on the relationship between concentration and certain physical characteristics of typical Brazilian soils. The results of previous studies investigating the migration of contaminants were used to develop mathematical expressions from multiple non-linear regressions. Using minimal squares regression, this transport was linked to various combinations of contaminant concentration and both structural and textural characteristics of the porous medium. Various combinations of characteristics and concentrations were investigated, with a mathematical expression obtained for each. The relationship between percentage of clay and the contaminant content proved to be the most closely correlated with actual transport parameters, with coefficients close to one.

Comparative embryology and taxonomic considerations in Eriocaulaceae (Poales)

The genus concept within Eriocaulaceae is widely discussed because it is mainly based on a small number of floral characteristics of unknown functional and evolutionary significance. The aim of the present work is to comparatively study the embryology of representatives of most genera of Eriocaulaceae to identify relevant features that might aid in circumscribing them. In Eriocaulaceae, the uniformity of the embryological characteristics makes it difficult to interpret the existing relationships among the genera. Some embryological characteristics, especially those related to the number of microsporangia, are shown to be unstable and restricted to Paepalanthoideae. The unique pollen morphology may be related to mechanical processes to accommodate the increase in volume after early formation of the pollen wall and may indicate a relationship to an inaperturate ancestor. The placentation, formerly stated to be axile, is more likely to be central due to protusions of the locular base. The shape of the proximal region of the megagametophyte may be responsible for the formation of the antipodal cyst. The seed coat structure is uniform in origin and is a consistent taxonomic characteristic of the family. A review of Eriocaulaceae is necessary, in which additional morphological and anatomical characteristics should be considered and combined. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Uso de Dois Espaçamentos Entre Gotejadores na Mesma Linha Lateral e Seus Efeitos Sobre a Formação do Bulbo Molhado no Solo e Parâmetros Físicos de Rabanete

The use of irrigation systems that consume lower water and energy in agriculture is important to supply the growing global demand for food. In this way, it's important to develop techniques that will increase the uniformity of water application on drip irrigation systems. The aim of the work was to compare the provision of lateral lines in drip irrigation, through the formation of wet bulbs in soil and physical parameters of radish, composed of single spacing between drippers in relation to lateral lines composed of two segments, each one composed by different spacing between emitters. Two distributions of evaluation were carried out: 1) conventional drip lateral lines with 20 cm emitter spacing were compared to proposed drip lines, with 24 emitter spacing in the initial section and 20 cm emitter spacing in the final section; 2) conventional drip lateral lines with 30 cm emitter spacing were compared to proposed drip lines, with 36 emitter spacing in the initial section and 30 cm emitter spacing in the final section. The experiment was carried out in a greenhouse of the Sao Manuel Experimental Farm, located at Sao Manuel, SP. The experimental design was entirely randomized, with six treatments and four replications. Results showed no difference among treatments for the most of the evaluated variables. So it is possible to conclude that the use of different spacing between emitters in the same lateral line can be used to increase the line length.

Water productivity assessment by using MODIS images and agrometeorological data in the Petrolina municipality, Brazil

The municipality of Petrolina, located in the semi-arid region of Brazil, is highlighted as an important agricultural growing region, however the irrigated areas have cleared natural vegetation inducing a loss of biodiversity. To analyze the contrast between these two ecosystems the large scale values of biomass production (BIO), evapotranspiration (ET) and water productivity (WP) were quantified. Monteithś equation was applied for estimating the absorbed photosynthetically active radiation (APAR), while the new SAFER (Simple Algorithm For Evapotranspiration Retrieving) algorithm was used to retrieve ET. The water productivity (WP) was analysed by the ratio of BIO by ET at monthly time scale with four bands of MODIS satellite images together with agrometeorological data for the year of 2011. The period with the highest water productivity values were from March to April in the rainy period for both irrigated and not irrigated conditions. However the largest ET rates were in November for irrigated crops and April for natural vegetation. More uniformity of the vegetation and water variables occurs in natural vegetation, evidenced by the lower values of standard deviation when comparing to irrigated crops, due to the different crop stages, cultural and irrigation managements. The models applied with MODIS satellite images on a large scale are considered to be suitable for water productivity assessments and for quantifying the effects of increasing irrigated areas over natural vegetation on regional water consumption in situations of quick changing land use pattern. © 2012 SPIE.

Variação entre a lâmina de irrigação aplicada e armazenada no solo sob condições de irrigação com baixa uniformidade de distribuição de água

In sprinkler irrigation is important to have a good uniformity of application so that the water in the root zone does not show areas with little available water while others have percolating beyond the plant roots, even though the soil allows a lateral redistribution of water. A usual way to obtain the uniformity of irrigation is by measures of dispersion. The aim of this work was to evaluate the uniformity of water stored in a sand soil before and after non uniformity depth irrigation applied from one sprinkler, as well the variation of storage in a 0-0,45 m layer soil using a neutron probe. The statistical design was completely randomized, and for the variable Christiansen uniformity coefficient modified (CUCHH) were 10 treatments (the irrigation depth, 8 intervals of readings storage, more the existing one before irrigation added to the irrigation depth). For the variable soil water, the treatments were the same, excepting the irrigation depth. Despite the low surface uniformity (16.3%), there was not significantly difference between the storage uniformity before, after irrigation and the potential, however there was from these to the surface uniformity. From de irrigation depth, 15.3 mm, only 6.1 mm remained in the layer from 0 to 0.45 m. There was not significantly difference between the water stored in the soil before and after irrigation within a period of up to 134 hours, being the increase in storage due to irrigation was just 11.7%.

Volume de aplicação na qualidade da deposição da pulverização na cutura do algodoeiro

Pós-graduação em Agronomia (Agricultura) - FCA

Expressão de genes em sementes de lobeira (Solanum Lycocarpum St Hill) submetidas ao condicionamento fisiológico

Pós-graduação em Agronomia (Agricultura) - FCA