The electronic detail of a digital pH-meter

This paperwork presents the complete circuitry used to build a microcontroller-based pH-meter. Key control software is also discussed. An industry-standard glass combination electrode has been employed for pH detection. Electrode parameter extraction procedure is presented. Good measurement results, with 1 % error, have been attained. Copyright© (2006) by the International Measurement Federation (IMEKO).

Estudo dos procedimentos utilizados para obtenção de microrretenções na superfície interna da porcelana: avaliação por meio de testes de rugosimetria e microscopia eletrônica de varredura

Pós-graduação em Ciências Odontológicas - FOAR

Caracterização microestrutural e resistência à corrosão de ligas Co-Cr-Mo utilizadas em próteses dentárias

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Contração de polimerização e expansão higroscópica de resinas compostas: análise pela técnica de video-imagem

To evaluate the volumetric changes due to polymerization and thermocycling on different resin-composites. Methods: Thirteen A2 Universal Dentin shade resin-composites (n = 10) from eight manufacturers were evaluated (4Seasons, Grandio, Venus, Amelogen Plus, P90, Z350, Esthet-X, Amaris, Vita-l-escence, Natural-Look, Charisma, Z250 and Opallis). The polymerization shrinkage percentage (PS) was calculated using an image measurement device (ACUVOL - Bisco Dental). Equal volumes of material, standardized by a semisphere polyurethane matrix (d = 3mm) were used and, after 5 minutes of relaxation, the baseline volume measurements were obtained with 18 J of energy dose from the LED light-curing unit. Measurements were obtained after 5 minutes and PS values calculated. Specimens were stored in a drydark environment for 24 hours and re-measured. Specimens were then thermocycled in distilled water between 5oC and 55oC for 20,000 cycles, subjected to another volume measurement at 5,000 cycle intervals. Specimens were gently dried prior to each measurement. Results: Repeated measurements were made using ANOVA (α = 0.05) showed that all resin-composite volumes were influenced by the number of cycles. Volumes at 5 minutes post-polymerization (12.47 ± 0.08) were significantly lower than those at baseline (12.80 ± 0.09). Volumes at 24 hours (12.43 ± 0.19) were insignificantly lower than those at 5 minutes postpolymerization. With regards to the impact of thermocycling, all specimens showed statistically significant increases in volume after 5,000 cycles (13.04 ± 0.22). Although statistically different from those after 5,000 cycles, there was no statistically significant difference between volumes measured at 10,000 (12.87±0.21), 15,000 (12.92±0.24), and 20,000 (12.84±0.23) cycles. Conclusion: According to the video-imaging analysis, thermocycling caused a significant expansion in resin-composites tested, the volume increase was not able to...

Imagens aéreas multiespectrais na identificação de zonas de manejo em áreas de algodão para aplicação localizada de insumos

Crop yield is influenced by several factors with variability in time and space that are associated with the variations in the plant vigor. This variability allows the identification of management zones and site-specific applications to manage different regions of the field. The purpose of this study was the use of multispectral image for management zones identification and implications of site-specific application in commercial cotton areas. Multispectral airborne images from three years were used to classify a field into three vegetation classes via the Normalized Difference Vegetation Index (NDVI). The NDVI classes were used to verify the potential differences between plant physical measurements and identify management zones. The cotton plant measurements sampled in 8 repetitions of 10 plants at each NDVI class were Stand Count, Plant Height, Total Nodes and Total Bolls. Statistical analysis was performed with treatments arranged in split plot design with Tukey’s Test at 5% of probability. The images were classified into five NDVI classes to evaluate the relationship between cotton plant measurement results and sampling location across the field. The results have demonstrated the possibility of using multispectral image for management zones identification in cotton areas. The image classification into three NDVI classes showed three different zones in the field with similar characteristics for the studied years. Statistical differences were shown for plant height, total nodes and total bolls between low and high NDVI classes for all years. High NDVI classes contained plants with greater height, total nodes and total bolls compared to low NDVI classes. There was no difference in Stand Count between low and high NDVI classes for the three studied years. The final plant stand was the same between all NDVI classes for 2001 and 2003 as it was expected due to the conventional seeding application with the same rate of seeds for the entire field.

Measurement of sealant surface area by clinical/computerized analysis: 11-year results.

OBJECTIVE: To analyze the clinical behavior of 2 pit and fissure sealants through clinical/computerized evaluation. METHOD AND MATERIALS: Occlusal sealants were placed on maxillary and mandibular first and second premolars according to a split-mouth design. All premolars were sealed with either Concise (3M Espe) or Prisma Shield (Caulk/Dentsply) sealant agents. A hematoxylin-based staining solution was applied on the occlusal surface 7 days, 18 months, 36 months, and 11 years after occlusal sealing to allow checking of the sealant material on the surface. At each analysis time all occlusal surfaces were photographed, and the photographs corresponding to each time period were analyzed with SigmaScan 4.0 Software. The alterations of the sealed area of each sealant were analyzed with the software and recorded. Next, the measurements of the areas were tabulated and analyzed according to each period. Analysis of variance (ANOVA), with parts subdivided into time, and the t test, with a significance level of 5%, were used. RESULTS: The greatest sealed area was maintained by the sealant Concise. However, over the course of 11 years, all sealants began to show the same level of alteration in sealed area. CONCLUSION: The sealing materials showed alteration in sealed area over time, but they were efficient in controlling caries lesion formation on premolar pits and fissures.

Modeling approach based on experimental results for prediction of measurement errors in energy meters

This paper presents a general modeling approach to investigate and to predict measurement errors in active energy meters both induction and electronic types. The measurement error modeling is based on Generalized Additive Model (GAM), Ridge Regression method and experimental results of meter provided by a measurement system. The measurement system provides a database of 26 pairs of test waveforms captured in a real electrical distribution system, with different load characteristics (industrial, commercial, agricultural, and residential), covering different harmonic distortions, and balanced and unbalanced voltage conditions. In order to illustrate the proposed approach, the measurement error models are discussed and several results, which are derived from experimental tests, are presented in the form of three-dimensional graphs, and generalized as error equations. © 2009 IEEE.

Alternative Intrabladder Manometry Technique for the Indirect Measurement of Intra-abdominal Pressure in Horses

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

Measurement systems of soil water matric potential and evaluation of soil moisture under different irrigation depths

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Measurement of oxygen atom diffusion in Nb and Ta by anelastic spectroscopy

Impurity interstitial atoms present in metals with BCC structure can diffuse in the metallic matrix by jumps to energetically equivalent crystallographic sites. Anelastic spectroscopy (internal friction) is based on the measurement of mechanical loss or internal friction as a function of temperature. Due to its selective and nondestructive nature, anelastic spectroscopy is well suited for the study of diffusion of interstitial elements in metals. Internal friction measurements were made using the torsion pendulum technique with oscillation frequency of a few Hz, temperature interval from 300 to 700 K, heating rate of about 1 K/min, and vacuum better than 10-5 mbar. The polycrystalline Nb and Ta samples used were supplied by Aldrich Inc. The results obtained showed thermally activated relaxation structures due to stress-induced ordering of oxygen atoms around the Nb (or Ta) atoms of the metallic matrix. The results were interpreted by three methods and led to activation enthalpy values for the diffusion of oxygen in Nb and Ta of 1.15 eV and 1.10 eV, respectively.

A New Impedance Measurement System for PZT-Based Structural Health Monitoring

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ultrasonic density measurement cell design and simulation of non-ideal effects

This paper presents a theoretical analysis of a density measurement cell using an unidimensional model composed by acoustic and electroacoustic transmission lines in order to simulate non-ideal effects. The model is implemented using matrix operations, and is used to design the cell considering its geometry, materials used in sensor assembly, range of liquid sample properties and signal analysis techniques. The sensor performance in non-ideal conditions is studied, considering the thicknesses of adhesive and metallization layers, and the effect of residue of liquid sample which can impregnate on the sample chamber surfaces. These layers are taken into account in the model, and their effects are compensated to reduce the error on density measurement. The results show the contribution of residue layer thickness to density error and its behavior when two signal analysis methods are used. (c) 2006 Elsevier B.V. All rights reserved.

Real-time multi-sensors measurement system with temperature effects compensation for impedance-based structural health monitoring

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Viscosity measurement of Newtonian liquids using the complex reflection coefficient

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

A new short and simple health-related quality of life measurement for paediatric rheumatic diseases: initial validation in juvenile idiopathic arthritis

Objective. To develop and validate a new short and simple measure of health-related quality of life (HRQL) in children with juvenile idiopathic arthritis (JIA).Methods. The Paediatric Rheumatology Quality of Life Scale (PRQL) is a 10-item questionnaire that explores HRQL in two domains: physical health (PhH) and psychosocial health (PsH). Validation of the parent proxy report and child self-report versions of the instrument was accomplished by evaluating 472 JIA patients and similar to 800 healthy children. Validation analyses included assessment of feasibility, face and content validity; construct and discriminative ability; internal structure and consistency; test-retest reliability; responsiveness to clinical change; and minimal clinically important difference.Results. The PRQL was found to be feasible and to possess both face and content validity. The PRQL score correlated in the predicted range with most of the other JIA outcome measures, thereby demonstrating good construct validity, and discriminated well between different levels of disease severity. Assessment of internal structure (factor analysis) revealed that the PhH and PsH subscales identify two unambiguously separated domains. The internal consistency (Cronbach's alpha) was 0.86. The intraclass correlation coefficient for test-retest reliability was 0.91. The PRQL revealed fair responsiveness, with a standardized response mean of 0.67 in improved patients. Overall, the PRQL appeared to be more able to capture physical HRQL than psychosocial HRQL.Conclusion. The PRQL was found to possess good measurement properties and is, therefore, a valid instrument for the assessment of HRQL in children with JIA. This tool is primarily proposed for use in standard clinical care.