Amônia (NH3) atmosférica: Fontes, transformação, sorvedouros e métodos de análise

Ammonia is the most common alkaline gas of the atmosphere, being important in the neutralization of various processes that occur in the atmosphere. Its main sources of emission are the decomposition of organic matter and dejections of animals. Ammonia is used by man in diverse activities of production, therefore it is a gas that can contaminate work environments. Measurements of ammonia concentration in some parts of the world have shown great spatial and weather variation. This large variability makes it difficult to estimate the input of reduced nitrogen to different ecosystems from measurements.

Comparação de métodos de determinação da gravidade específica de ovos de poedeiras comerciais

The objective of this work was to compare the results of measuring the specific gravity (SG) of laying hen eggs by using a weighing apparatus and the saline flotation method (SFM). Two hundred eggs from two genetic lines were distributed randomly into two groups of 50 eggs per genetic line and were submitted to two different sequences of SG measurement. Not significant differences were found between the two methods. The weighing apparatus measured the SG of the eggs accurately as the SFM.

Métodos de coleta de fezes e determinação dos coeficientes de digestibilidade da fração protéica e da energia de alimentos para o pacu, Piaractus mesopotamicus (Holmberg, 1887)

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

Avaliação da eficiência dos métodos Direto, COPROTEST e Rugai no diagnóstico da estrongiloidíase

Strongyloidiasis, a relatively common parasitism in tropical and sub-tropical areas, is the result of the infection by the smaller nematode, the Strongyloides stercoralis. Humans can be infected by this parasite, which has in its vital cycle free-life forms of male and female individuals able to live in the ground, and with another step necessary parasitism in the intestinal wall. The diagnostic of the infection is routinely done by the microscopic observation of the larva in stool samples and the high sensibility of urn method over another one allows an trustable and efficient diagnostic. The efficiency of three methods (Direct, COPROTEST and Rugai) used in the Parasitology Sector of the NAC-LACAL in Araraquara (SP) to diagnosis the strongiloidiasis were evaluated. A number of 2346 samples of stool of patients from NAC-LACAL and Nestor Goulart Reis Hospital were analyzed in the period between August and December of 2002. The Rugai Method with an positivity index of 65 % was elected as the most efficient of thee ones.

Análise comparativa de métodos de avaliação da composição corporal em homens sadios e em pacientes com doença pulmonar obstrutiva crônica: antropometria, impedância bioelétrica e absortiometria de raios-X de dupla energia

The aim of this study was to examine the agreement between the results of body fat (BF and BF%), fat-free mass (FFM) and FFM index (FFMI= FFM/height2) as estimated by skinfold anthropometry (ANT), bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA) in two groups of men (> or = 50 y), one comprising healthy individuals (n=23) and the other, patients with chronic obstructive pulmonary disease (COPD) (n=24). Comparisons between body composition techniques were done by repeated measures ANOVA; the Bland & Altman procedure was used to analyse agreement. RESULTS AND CONCLUSIONS: 1) comparison between healthy and COPD groups showed significant differences between all studied variables; 2) in the healthy group, values for BF, BF%, FFM and FFMI were not significantly different when BIA or ANT was compared to DXA; however, in COPD, values for BF and BF% were significantly higher and for FFM and FFMI significantly lower when BIA was compared to DXA; in contrast, no differences were shown between values for these variables when ANT was compared with DXA; 3) Bland & Altman test, in both groups, showed no agreement between BIA and DXA and between ANT and DXA; it was also shown that body fat was overestimated and fat free mass underestimated by BIA in relation to DXA.

Uso de métodos químicos para obtener polvos cerámicos del sistema (Sn, Ti)O2

The (Sn,Ti)O2, system has a great interest due to its technological applications such as gas sensor and varistor. Although the thermodynamic properties and the kinetics of spinoidal decomposition in this system have been extensively studied, the general properties and applications of SnO2 - TiO2 binary compositions have been not investigated yet in depth. On the other hand, little work has been done to optimize the synthesis methods to obtain (Sn,Ti)O2 cerallmic powders, with pre - determinate physical and chemical characteristics. In this work the ceramic powders has been obtained by coprecipitation and polymeric precursor (Pechini) methods. The different physical chemistry phenomena that occurred during the synthesis were discussed. The (Sn,Ti)O2, ceramic powders were characterized with X- ray diffraction (XRD), thermal analysis (DTA/TG) and scanning electron microscopy (SEM). The knowledge about of steps and variables of synthesis process acquired with development of this work, we permited to obtain (Sn, Ti)O2, nanometers particles to low temperatures: to 450°C for coprecipitation method and to 600°C for Pechini method. The spinodal decomposition that ocurr to 900°C was discussed also.

Diagnóstico de uma área compactada por atividade minerária, na floresta amazônica, empregando métodos geoestatísticos à variável resistência mecânica à penetração do solo

A quite common problem in the recovery of degraded areas in the mineral exploration understands the compaction of the soil due to the intense traffic of machines and earth movement. The most common problem of the compaction of a degraded surface is: increase of the mechanical resistance to the penetration of the rooats, reduction of the aeration, alteration of the water flow and heat. Thus the present work had the basic objective of diagnosing the compaction of a degraded area by mining in a space way, through the mechanical resistance the way penetration to guide a future subsoiling in the place seeking recovery. Through the studies it was concluded that the kriging method in agreement with the space variation allows the division of the area studies in sub areas facilitating a future work to reduce cost and unnecessary interference to the atmosphere. The method was shown quite appropriate and it can be used in diagnosis of the compaction in a degraded area by mining, foreseeing subsoiling need.

Comparação de dois métodos de aplicação de fungicidas, irrigação por gotejamento e pulverização convencional no controle do mofo cinzento (Botrytis cinerea Pers.: Fr.) em vasos com plantas de lisianthus (Eustoma grandiflorum (Raf.) Shinn.)

Plan disease control techniques are used through the irrigation water, which reduces the labor and it improves application uniformity with smaller contact of the operator with toxic products, lower environmental impact and lower production cost. In order to control Botrytis cinerea the lisianthus culture, this work aimed to evaluate two fungicide application methods with different treatments. The fungicides were: thiophanate methyl (50 g i.a. L-1), thiophanate methyl + chlorothalonil (50 g i.a. L-1 + 35 g i.a. L-1) and iprodione (50 g i.a. L-1). Number of lesions, number of diseased floral buttons and height of the lisianthus plants were evaluated. It was possible to deduce, that in the growth stage (number of lesions in the plant) as well as in the final stage (number of floral buttons) of the lisianthus culture, the most efficient treatments were 2 (thiophanate methyl + chlorothalonil) and 3 (iprodione). Considering that treatment 2 is a mixture of two fungicides, a systemic and a contact one, independently of application methods, the mixture increased efficiency in relation to treatment 1 (thiophanate methyl). Thus, chemigation was as efficient as spreading technique.

Métodos químicos para obtener varistores basados en SnO2

Synthesis of SnO2 ceramic powders was made by coprecipitation method and polymeric precursor method (Pechini) to obtain Sn-Co-Nb-Ti-Al varistor systems. The particles of the obtained ceramic powder presented nanometric size and SnO2 was the principal crystalline phase in them according to X-ray diffraction results. To determine the behavior of the synthesized samples in front of the thermal treatments, thermal analysis (DTA/TG) were made. Dilatometric studies on previously pressed samples were carried out. The optimal conditions of sintering of this raw material were determined. Microstructures and electric properties of sintered samples were studied using scanning electron microscopy (SEM) and I-V characteristics curves. The samples presented varistor behavior independent of the synthesis method used, with high nonlinearity values as 32. The presence of Al3+ favored the concentration of oxygen vacancies, and the grain growth.

Avaliação estatística de métodos de poda aplicados em neurônios intermediários da rede neural MLP

There are several papers on pruning methods in the artificial neural networks area. However, with rare exceptions, none of them presents an appropriate statistical evaluation of such methods. In this article, we proved statistically the ability of some methods to reduce the number of neurons of the hidden layer of a multilayer perceptron neural network (MLP), and to maintain the same landing of classification error of the initial net. They are evaluated seven pruning methods. The experimental investigation was accomplished on five groups of generated data and in two groups of real data. Three variables were accompanied in the study: apparent classification error rate in the test group (REA); number of hidden neurons, obtained after the application of the pruning method; and number of training/retraining epochs, to evaluate the computational effort. The non-parametric Friedman's test was used to do the statistical analysis.

Estudo comparativo da pressão arterial sistêmica obtida por dois métodos distintos

As arterial hypertension can be diagnosed by different methods, among which are the traditional auscultatory instrument and the automated oscillometric monitor, the aim of this study was to compare the performance of these instruments, to evaluate the reliability of the digital oscillometer. The sample consisted of 40 patients under dental treatment, whose blood pressure measurements were recorded. The measurements of systolic and diastolic blood pressures were evaluated in terms of their intraclass correlation coefficients (r). For systolic blood pressure, an excellent level of agreement was found between the instruments, with r=0.93, and for diastolic blood pressure, there was a good level of agreement (r=0.75). It was concluded, from the excellent agreement for systolic blood pressure, that the oscillometric monitor can be recommended for the monitoring of the variations of that pressure in the same individual, while the good agreement obtained in the determination of the diastolic blood pressure indicates that the oscillometric method is reliable. However, new studies need to be carried out for a better understanding of the disagreements that can occur in the diastolic pressure results.

Avaliação de diferentes métodos no diagnóstico laboratorial de Giardia lamblia

The protozoan parasite Giardia lamblia is responsible for a common intestinal infection in all regions of the world. In this study, four laboratory tests were evaluated for diagnostic reproducibility in the detection of this infection: Coprotest®, Direct modified method, Faust method and iron-hematoxylin staining. Positive diagnoses were tested for association with factors such as the age group and gender of the subject and the month when the sample was taken. Feces of 200 children in the Araraquara region (SP, Brazil) were examined by all four methods and the results compared. G. lamblia was found to be the most frequent parasite and 8.0% of the children showed giardiasis. There was no apparent correlation with gender, but most of the parasites were found in three- to five-year-olds. The highest frequency of infection occurred in January. The most reliable diagnostic results for G. lamblia were achieved by combining at least two methods of good reproducibility, i.e. Coprotest-Faust, Direct-Faust or Coprotest-Direct (A > 0.81).

Comparación de tres métodos para estimar estabilidad del rendimiento en nueve variedades de algodón

With the purpose of selecting and recommending promissory cultivars of cotton, Gossypium hirsutum (L) with high yield potential and stability, for crop areas in Venezuela, the yield (seed included) of nine cotton varieties was evaluated. The data from the 1995-96 and 1996-97 cycles was used. The experimental design was a randomized completed block design with four repetitions on twelve environments. Parameters of stability offered by the methods of Eberhart and Russell, (1966), Cruz et al. (1989) and the AMMI model were estimated and compared to determine the best method or combination. There was no coincidence between the best yield varieties, Unellez-2 and the commercial variety Delta Pine 16, in relation to stability criteria. According to Eberhart and Russell, these were classified as stable, while according to Cruz et al. they were adaptive to favorable environments and according to AMMI they were unstable with high interaction,.Of the three methods studied, the AMMI model allowed associating the response of high yield varieties to specific environments, gave more information and was easier to interpret.

Comparação entre trȩs métodos para estimar lâminas de irrigação

An experiment with four treatments was carried out on the experimental area of ADEI to compare three methods of water use requirement: ETc (T1) - irrigation based on crop evapotranspiration (ETc); Tensiometers (T2 and T3) - irrigations were made through reading of tensiometers installed at 40 cm deep and, Control (T4) - only one irrigation to promote the seedlings emergence. Both Class A pan and soil water depletion methods presented good results when the crop was developed without restraint of water. The Katerji method can be utilized in conditions of water restriction. Irrigation frequency was more important than amount of applied water for higher yield.