Colorimetric determination of sulfur dioxide in air using a droplet collector of malachite green solution

The measurement of sulfur dioxide in air at the parts-per-billion level is described. The experimental arrangement consists of two optical fibers placed on opposite sides of a liquid droplet of malachite green solution. After light has been passed through the droplet, the transmitted light is measured by a referenced photodetection arrangement. The light used in this absorption process is from a monochromatic source (lambda(max) 625 nm). This arrangement permits the variation of color in the droplet to be measured. The sulfur dioxide in the sample is collected by the droplet; it reacts with malachite green resulting in a colorless dye. The decoloration of the solution is proportional to the concentration of sulfur dioxide sampled. The signal depends on the sample flow rate. The present technique is simple, inexpensive, and permits a fast and near real time measurement while consuming very little reagent, (C) 1999 Academic Press.

Measurement of atmospheric formaldehyde using a drop collector and in-situ colorimetry

A sensitive and affordable approach is described for the in-situ measurement of ambient formaldehyde. Air is sampled around a 100 microliter aqueous drop containing 3-methyl-2-benzothiazoline hydrazone. After a desired period of sampling (typ. 5 min) and a waiting period of 10 min for the reaction to be completed, a second reagent (FeCl3) is added to the drop by means of a conjoined conduit. A blue product is formed and is read after an additional 10 min of reaction by a fiber-optic/light emitting diode based photodetector. A fresh drop is then formed and the process begins anew. As demonstrated here, the limit of detection is similar to 6.25 mu g m(-3) HCHO but can be significantly improved by using longer sampling times and a sampling rate higher than 100 mi min(-1) used in most of this work. This is the first example of a chromogenic drop sensor that utilizes sequential reagent addition.

Autonomous mobile robots designing for the medical trash collector task

This paper describes the UNESP robotic team in the medical trash collector task, proposed on the 5 rd IEEE Latin American Robots Competition in the LEGO category. We present our understanding of the task and discuss the proposed solution, focusing on the mechanical and computational issues of the robots. The mechanics is based on rigid body capability of transforming rotational into curvilinear movement. With respect to the computational control, the system is modeled as a reactive system with sequential transition of behaviors. A state-machine is proposed to allow this transition, and the synchronization of robotic states is guaranteed by the communication system. The proposed approach has shown itself capable of dealing with the high difficulty degree of this cooperative task. ©2006 IEEE.

Numerical analysis of a modified evacuated tubes solar collector

The need for renewable energy sources, facing the consequences of Climate Change, results in growing investment for solar collectors’ use. Research in this field has accompanied this expansion and evacuated tube solar collector stands as an important study focus. Thus, several works have been published for representing the stratification of the fluid inside the tubes and the reservoir, as well as analytical modeling for the heat flow problem. Based on recent publications, this paper proposes the study of solar water heating with evacuated tubes, their operation characteristics and operating parameters. To develop this work, a computational tool will be used - in this case, the application of computational fluid dynamics (CFD) software. In possession of the implemented model, a numerical simulation will be performed to evaluate the behavior of the fluid within this solar collector and possible improvements to be applied in the model.

Analisys of thermal efficiency of a modified solar collector type evacuated tube

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Recursos pesqueiros oriundos da pesca artesanal no reservatório de jurumirim, rio Paranapanema, Alto Paraná, Brasil

The aim of this paper was to evaluate the artisanal fisheries in the village of fishermen of Bairro da Ponte, Jurumirim reservoir. Data were collected using production forms which were filled daily by a data collector, in 2005 and 2006. The fishery yield was estimated at 15.7 kg ha(-1) year(-1), the average yield was 12.5 t year(-1) and catch per unit effort (CPUE) was 10.5 kg fisherman(-1) day(-1). We recorded 26 species of landed fish in this activity, being the "traira" (Hoplias malabaricus) the most landed fish in terms of biomass with 6,158.5 kg, representing 24.5%, of the total landed. Seasonally, the CPUE ranged from 14.5 kg fisherman(-1) day(-1) in summer/2005 to 9.0 kg fisherman(-1) day(-1) in spring/2006. The average CPUE by type of fish also showed a marked seasonality. In summer of 2005 and 2006, "curimbata" was the most landed fish, with CPUE kg fisherman(-1) day(-1) of 6.9 and 6.2, respectively. The "piavas" were the most landed fish in autumn with CPUE of 2.4 (year 2005) and 2.3 (year 2006) kg fisherman(-1) day(-1), and "traira" in winter with CPUE ranging from 3.0 to 4.0 kg fishrman(-1) day(-1), in 2005 and 2006, respectively. The mathematical modeling of simple linear regression indicated positive relationships between the monthly fish production and the number of boats in activity and of fishing trips. The study concluded that fishing is sustained only by native species; with marked seasonality for catching fish and that the area of fishing examined of the Jurumirim reservoir is among the most productive areas of the Upper Parana basin.

Avaliação da chuva de sementes em áreas de restinga em diferentes estágios de regeneração

This study was conducted in an area of restinga in the municipality of Silo Vicente (SP). The study aimed to evaluate the seed rain in three different conditions of regeneration. Was selected the following conditions: High Forest of Restinga in the middle stage of regeneration, an area of clearing in the same condition mentioned above and a third in early stages of regeneration. hi each condition were installed 10 seed collectors made of wood and screen with 80% of shade, supported to a height of 20cm of soil. They were evaluated monthly for one yew; the densities of seed deposited in the collector these seedlings are identified and categorized based on their dispersion syndrome and successional classes. The Area of High Forest area was carried out a phytosociological survey to identify which seedlings present in the rain could be from these areas. It was found that the densities of seedlings are relatively low compared to other formations of the Atlantic rain forest, but consistent with other studies of the same type of vegetation used in the study. Regarding dispersal syndromes and successional classes, there was prevalence of the zoocoric syndrome and species of secondary successional classes. The results indicate that the area has good ability to maintain their succession dynamics.

Artisanal fisheries in urban reservoirs: a case study from Brazil (Billings Reservoir, São Paulo Metropolitan Region)

Billings Reservoir is an urban reservoir located in the São Paulo Metropolitan Region. Tt supports 101 active artisanal fishermen. To describe this fishery, landings were recorded daily between February 1996 and January 1997 at Colonia (23 degrees 50' 57 S; 46 degrees 40' 02 W). In every landing, a data collector recorded catch, effort, fishing gears and fishing grounds. A total of 147 593 kg of fish were recorded in 3515 fishing trips. The exotic Nile tilapia, Oreochromis niloticus (L.), was the main species exploited (81.4% of the annual catches). Five other species were also targeted: the characid Astyanax eigenmaniorum (Cope) (13.0% of the annual catches); the erythrinid Hoplias aff malabaricus (Block) (2.1%); the exotic cyprinid Cyprinus carpio L. (Campos & Fernandez-Yepez) (2.4%); the curimatid Cyphocharax modestus L. (1.1%); and the pimelodid Rhamdia sp. (0.1%). Two main groups of fishermen were discriminated using Principal Components Analysis; these were associated with the type of fishing gear and fishing strategies, i.e. those who exploited Nile tilapia with cast nets and beating gill nets, and those who exploited other species with set gill nets. Management and maintenance of this fishery should consider the positive top-down effects that Nile tilapia could have in controlling eutrophication and also the social benefits.

Impedance Spectroscopy Analysis of the Effect of TiO2 Blocking Layers on the Efficiency of Dye Sensitized Solar Cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bioaccumulation of metals in aquatic insects of streams located in areas with sugar cane cultivation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The invertebrate colonization during decomposition of Eichhornia azurea kunth in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir (São Paulo, Brazil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Substâncias húmicas aquáticas: fracionamento molecular e caracterização de rearranjos internos após complexação com íons metálicos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Classificação de tomate-cereja em função do tamanho e peso dos frutos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Multi-method Study on Aquatic Humic Substances from the Rio Negro - Amazonas State/Brazil: Emphasis on Molecular-Size Classification of their Metal Contents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of autogenous bone grafts, particulate or collected during osteotomy with implant burs: Histologic and histomorphometric analysis in rabbits

Purpose: the aim of this study was to evaluate bone regeneration in bone cavities filled with particulate autogenous bone either harvest in blocks and subjected to milling procedures or collected during osteotomy with implant burs. Materials and Methods: In 12 rabbits, 3 noncritical unicortical cavities 7 mm in diameter were prepared with a trephine drill on the right tibia. The cavities were filled respectively with particulate autogenous bone achieved with a manual bone crusher ( particulate group), with particulate autogenous bone obtained using bone collector during osteotomy ( collected group), and with blood clot ( control group). Animals were sacrificed at 7, 15, and 30 days after surgery ( 4 animals for each time period). The sections were examined by histologic and histomorphometric analysis. Results: At 7 days, the samples were filled by coagulum, and bone particles were observed only in the collected (24%) and particulate groups (44.75%). At 15 days, there was connective differentiation in all groups, with presence of grafted bone particles and onset of newly formed bone in the collected (38.88%) and particulate groups (46.0%). At 30 days, there was bone fill ( immature trabecular bone) of the cavities in the control (50%), collected (64.63%) and particulate groups (66%). Conclusion: No significant difference was demonstrated between noncritical unicortical bone defects in rabbit tibiae filled with particulate bone harvested as a block and subjected to milling and those filled with bone collected during osteotomy with implant drills when the defects were observed up to 30 days following their creation.