Spatial variability of air dry bulb temperature and black globe humidity index in a broiler house during the heating phase

The air dry-bulb temperature (t db),as well as the black globe humidity index (BGHI), exert great influence on the development of broiler chickens during their heating phase. Therefore, the aim of this study was to analyze the structure and the magnitude of the t db and BGHI spatial variability, using geostatistics tools such as semivariogram analysis and also producing kriging maps. The experiment was conducted in the west mesoregion of the states of Minas Gerais in 2010, in a commercial broiler house with heating system consisting of two furnaces that heat the air indirectly, in the firsts 14 days of the birds' life. The data were registered at intervals of five minutes in the period from 8 a.m. to 10 a.m. The variables were evaluated by variograms fitted by residual maximum likelihood (REML) testing the Spherical and Exponential models. Kriging maps were generated based on the best model used to fit the variogram. It was possible to characterize the variability of the t db and BGHI, which allowed observing the spatial dependence by using geostatistics techniques. In addition, the use of geostatistics and distribution maps made possible to identify problems in the heating system in regions inside the broiler house that may harm the development of chicks.

Evaluation of the heating of broilers in shed by means of gas hoods and underfloor heating

This study was conducted to evaluate and compare the behavior of the heating inside poultry shed through gas hood and underfloor heating. The experiment was conducted in poultry shed belonging to the Federal Institute of Education, Science and Technology of Triângulo Mineiro Region, Uberlândia city – state of Minas Gerais (MG), Brazil. The dimensions of the shed are 24 meters long and 9.6 meters wide and with a ceiling height of 3.2 meters. The temperature was measured with an optical thermometer of Minipa brand, MT 350 model. It was used, to the analysis of temperature behavior, the public domain software FEMM 4.2, which uses finite elements techniques, with data collected from two lots. Underfloor heating is made using hot water flowing through a serpentine type system, which is installed below the bed; this hot water is from solar heaters. An energetic and economic assessment of the warming shed for raising chickens was realized. From the results obtained with the simulations, it may observe that the heating through the floor provides a more homogeneous distribution of temperature when compared with the hood heating. The flow of heat is upwards supplying, thus, the greatest need of heating of the bird, which is the pectoral part.

Solar energy use for water pre-heating in boilers of agro-industries

Energy consumption in the world has been growing every year. The industrial sector represents 27.32% of the world energy demand. Heating systems that use solar energy may contribute with a percentage of the total energy required by industries. This work aimed to study the use of vacuum solar collectors for water pre-heating in boilers. We used four collectors installed according to NBR 15,569; water flow through the tubes was 0.058 L/s, and temperature in the inlet and outlet pipes was measured. Results showed that instantaneous radiation, and inlet fluid and room temperatures are variables that influence the process, reaching water maximum temperature in the solar collector outlet of 97.9 °C, and efficiency of approximately 65% for most experiments. For the financial viability evaluation, the payback study was applied, which resulted in 4; 7 and 5 years, for the respective sources: firewood, LPG (liquefied petroleum gas), and electricity. Regarding the calculation of the annual contribution to the reduction of greenhouse gases, it was, respectively, 2.162 and 356 kg of CO2 per m² of collector tubes, in comparison with firewood and LPG.

Estimation of aircraft aerodynamic derivatives using Extended Kalman Filter

Design of flight control laws, verification of performance predictions, and the implementation of flight simulations are tasks that require a mathematical model of the aircraft dynamics. The dynamical models are characterized by coefficients (aerodynamic derivatives) whose values must be determined from flight tests. This work outlines the use of the Extended Kalman Filter (EKF) in obtaining the aerodynamic derivatives of an aircraft. The EKF shows several advantages over the more traditional least-square method (LS). Among these the most important are: there are no restrictions on linearity or in the form which the parameters appears in the mathematical model describing the system, and it is not required that these parameters be time invariant. The EKF uses the statistical properties of the process and the observation noise, to produce estimates based on the mean square error of the estimates themselves. Differently, the LS minimizes a cost function based on the plant output behavior. Results for the estimation of some longitudinal aerodynamic derivatives from simulated data are presented.

Non-Linear Unsteady Aerodynamic Response Approximation Using Multi-Layer Functionals

Non-linear functional representation of the aerodynamic response provides a convenient mathematical model for motion-induced unsteady transonic aerodynamic loads response, that accounts for both complex non-linearities and time-history effects. A recent development, based on functional approximation theory, has established a novel functional form; namely, the multi-layer functional. For a large class of non-linear dynamic systems, such multi-layer functional representations can be realised via finite impulse response (FIR) neural networks. Identification of an appropriate FIR neural network model is facilitated by means of a supervised training process in which a limited sample of system input-output data sets is presented to the temporal neural network. The present work describes a procedure for the systematic identification of parameterised neural network models of motion-induced unsteady transonic aerodynamic loads response. The training process is based on a conventional genetic algorithm to optimise the network architecture, combined with a simplified random search algorithm to update weight and bias values. Application of the scheme to representative transonic aerodynamic loads response data for a bidimensional airfoil executing finite-amplitude motion in transonic flow is used to demonstrate the feasibility of the approach. The approach is shown to furnish a satisfactory generalisation property to different motion histories over a range of Mach numbers in the transonic regime.

Interference of heating on the antimicrobial activity and chemical composition of Origanum vulgare L. (Lamiaceae) essential oil

Origanum vulgare L. (oregano), Lamiaceae, essential oil has a variety of biological properties and its antimicrobial activity has received a renewed interest for use in food conservation. The aim of this study was to evaluate the interference of heating on the antimicrobial activity and chemical composition of O. vulgare essential oil. The antimicrobial activity of the essential oil kept at room temperature and exposed to different heating temperatures (60, 80, 100 and 120 °C during 1 hour) was evaluated by observing antimicrobial effectiveness at absolute concentration and determining MIC values by the solid medium diffusion procedure. The essential oil chemical composition analysis was performed by GC-MS. O. vulgare essential oil showed interesting antimicrobial activity on all assayed microbial strains (Candida albicans, C.krusei, C. tropicalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica, Salmonella enterica, Serratia marcencens), noted by large growth inhibition zones (30-42 mm). Heating treatment showed no significant interference (p < 0.05) on the essential oil antimicrobial activity, noted by the development of microbial growth inhibition zones with similar or close diameters when evaluating the essential oil kept at room temperature and after exposure to different thermal treatments. MIC values oscillated between 10and 40 µL.mL-1 (20µL.mL-1 for most strains). However, no significant difference (p < 0.05) was noted among the MIC values found for the essential oil aliquots exposed to different temperatures. Moreover, heating did not significantly (p < 0.05) affect the chemical composition of O. vulgare essential oil. Monoterpenes, terpenic compounds and sesquiterpenes were found in the essential oil, with carvacrol (68.06-70.27%) and p-cymene (12.85-15.81%) being the compounds found in the highest amounts. These results showed the thermal stability and intense antimicrobial properties of O. vulgare essential oil and support its possible concomitant use with heating temperatures in order to reach microbial safety in foods.

Heating effects on physicochemical characteristics and antioxidant activity of flaxseed hull oil (Linum usitatissimum L)

The aim of this study was to analyze the effects of heating on some quality characteristics and antioxidant activity of flaxseed hull oil. Polyunsaturated fatty acids (PUFA) and Cox value decreased during heating. Heating process led to considerable increase in saponification value (SV), peroxide value (PV), p-anisidine value (p-AnV), oxidative value (OV) and specific extinction at 232 and 270 nm. There was a significant decrease in oil stability during heating process (1.4-1.0 h). Fuel properties of flaxseed hull oil were also changed after heating treatment. Heating process caused loss of total phenolic acids, total flavanoids, carotenoids and chlorophyll pigments. Phospholipids (PL) content were less changed compared to other bioactive compounds. Antioxidant activity of flaxseed hull oil decreased during heating process.

Comparison of different methods for the determination of total organic carbon and humic substances in Brazilian soils

ABSTRACTAiming to compare three different methods for the determination of organic carbon (OC) in the soil and fractions of humic substances, seventeen Brazilian soil samples of different classes and textures were evaluated. Amounts of OC in the soil samples and the humic fractions were measured by the dichromate-oxidation method, with and without external heating in a digestion block at 130 °C for 30 min; by the loss-on-ignition method at 450 °C during 5 h and at 600 °C during 6 h; and by the dry combustion method. Dry combustion was used as reference in order to measure the efficiency of the other methods. Soil OC measured by the dichromate-oxidation method with external heating had the highest efficiency and the best results comparing to the reference method. When external heating was not used, the mean recovery efficiency dropped to 71%. The amount of OC was overestimated by the loss-on-ignition methods. Regression equations obtained between total OC contents of the reference method and those of the other methods showed relatively good adjustment, but all intercepts were different from zero (p < 0.01), which suggests that more accuracy can be obtained using not one single correction factor, but considering also the intercept. The Walkley-Black method underestimated the OC contents of the humic fractions, which was associated with the partial oxidation of the humin fraction. Better results were obtained when external heating was used. For the organic matter fractions, the OC in the humic and fulvic acid fractions can be determined without external heating if the reference method is not available, but the humin fraction requires the external heating.

Isolated and synergistic effects of PM10 and average temperature on cardiovascular and respiratory mortality

OBJECTIVE To analyze the effect of air pollution and temperature on mortality due to cardiovascular and respiratory diseases. METHODS We evaluated the isolated and synergistic effects of temperature and particulate matter with aerodynamic diameter < 10 µm (PM10) on the mortality of individuals > 40 years old due to cardiovascular disease and that of individuals > 60 years old due to respiratory diseases in Sao Paulo, SP, Southeastern Brazil, between 1998 and 2008. Three methodologies were used to evaluate the isolated association: time-series analysis using Poisson regression model, bidirectional case-crossover analysis matched by period, and case-crossover analysis matched by the confounding factor, i.e., average temperature or pollutant concentration. The graphical representation of the response surface, generated by the interaction term between these factors added to the Poisson regression model, was interpreted to evaluate the synergistic effect of the risk factors. RESULTS No differences were observed between the results of the case-crossover and time-series analyses. The percentage change in the relative risk of cardiovascular and respiratory mortality was 0.85% (0.45;1.25) and 1.60% (0.74;2.46), respectively, due to an increase of 10 μg/m3 in the PM10 concentration. The pattern of correlation of the temperature with cardiovascular mortality was U-shaped and that with respiratory mortality was J-shaped, indicating an increased relative risk at high temperatures. The values for the interaction term indicated a higher relative risk for cardiovascular and respiratory mortalities at low temperatures and high temperatures, respectively, when the pollution levels reached approximately 60 μg/m3. CONCLUSIONS The positive association standardized in the Poisson regression model for pollutant concentration is not confounded by temperature, and the effect of temperature is not confounded by the pollutant levels in the time-series analysis. The simultaneous exposure to different levels of environmental factors can create synergistic effects that are as disturbing as those caused by extreme concentrations.

Isolation and characterization of partially purified leptospiral antigens

The methanol extract of Leptospira interrogans serovar canicola was purified by precipitation with acetone or acetone and chloroform. The antigenicity of the antigen was not altered by heating or treatment with pepsin and pronase. However the antigenicity was lost when the antigen was treated with periodic acid. Chemical analysis revealed the presence of 40% carbohydrate (22% methylpentose, 28%; hexoses),4% protein, 20% lipid and 2,7% phosphate. The complement fixation test with sera from patients with leptospirosis agreed with the microscopic agglutination reaction.

Leishmania braziliensis: isolation of carbohydrate-containing antigen and possibility of its use in the immunodiagnosis of American Cutaneous Leishmaniasis

Leishmania braziliensis is a causative agent of American Cutaneous Leishmaniasis (ACL). The 034-JCG strain, isolated from a patient from the northern region of Paraná State, Brazil, was cultivated in Blood Agar Base medium, lyophilized and submitted to phenol-water extraction. The extract was treated with RNase I. The carbohydrate containing-antigen (Ag-CHO) was immunogenic to rabbits and showed at least a fraction with some negative charge at pH 8.2. This antigen showed cross-reactivity with the phenol-water extract of the growth medium used for the culture of promastigotes and with the surface antigens of promastigotes. Its composition is: 24.3% of total sugars, from which 11.2% of galactose, 7.5% of mannose and 5.6% of ribose. Protein content was 5.4% and phosphate 18.5%. The antigenic activity was maintained after: repeated freezing-thawing; lyophilization; heating at 100ºC for 30 minutes; treatment with RNase, trichloroacetic acid and sodium metaperiodate. The precipitin line obtained is Periodic Acid Schiff positive. The application of the Ag-CHO in counterimmunoelectrophoresis reaction for the immunodiagnosis of ACL showed 60% sensitivity, and no cross-reaction with the five sera of Chagas' disease patients tested. The use of this antigen in a more sensitive technique, with more samples of sera, may improve these results.

EVALUATION OF A RAPID SCREENING ASSAY FOR BACTERIAL IDENTIFICATION (DOT-ELISA) IN FECAL SAMPLES FROM CHILDREN

With the objective of standardizing a Dot Enzyme-Linked Immunosorbent Assay (Dot-ELISA) to detect antigens of fecal bacterial enteropathogens, 250 children, aged under 36 months and of both sexes, were studied; of which 162 had acute gastroenteritis. The efficacy of a rapid screening assay for bacterial enteropathogens (enteropathogenic Escherichia coli "EPEC", enteroinvasive Escherichia coli "EIEC", Salmonella spp. and Shigella spp.) was evaluated. The fecal samples were also submitted to a traditional method of stool culture for comparison. The concordance index between the two techniques, calculated using the Kappa (k) index for the above mentioned bacterial strains was 0.8859, 0.9055, 0.7932 and 0.7829 respectively. These values express an almost perfect degree of concordance for the first two and substantial concordance for the latter two, thus enabling this technique to be applied in the early diagnosis of diarrhea in infants. With a view to increasing the sensitivity and specificity of this immunological test, a study was made of the antigenic preparations obtained from two types of treatment: 1) deproteinization by heating; 2) precipitation and concentration of the lipopolysaccharide antigen (LPS) using an ethanol-acetone solution, which was then heated in the presence of sodium EDTA

Breeding of Biomphalaria tenagophila in mass scale

An efficient method for breeding Biomphalaria tenagophila (Taim lineage/RS) was developed over a 5-year-period (2005-2010). Special facilities were provided which consisted of four cement tanks (9.4 x 0.6 x 0.22 m), with their bottom covered with a layer of sterilized red earth and calcium carbonate. Standard measures were adopted, as follows: each tank should contain an average of 3000 specimens, and would be provided with a daily ration of 35,000 mg complemented with lettuce. A green-house effect heating system was developed which constituted of movable dark canvas covers, which allowed the temperature to be controlled between 20 - 24 ºC. This system was essential, especially during the coldest months of the year. Approximately 27,000 specimens with a diameter of 12 mm or more were produced during a 14-month-period. The mortality rates of the newly-hatched and adult snails were 77% and 37%, respectively. The follow-up of the development system related to 310 specimens of B. tenagophila demonstrated that 70-day-old snails reached an average of 17.0 ± 0.9 mm diameter. The mortality rates and the development performance of B. tenagophila snails can be considered as highly satisfactory, when compared with other results in literature related to works carried out with different species of the genus Biomphalaria, under controlled laboratory conditions.

Lactacidemia: métodos de dosagem do ácido lático

A critical study of three methods for the determination of lactic acid (EDWARDS, MENDEL & GOLDSCHEIDER, MILLER & MUNTZ) is presented and some modifications are proposed. It was shown t hat more accurate results could be obtained with Edward's technic when an Iena glass filter is connected with the absorption tube. Before the dropping of the permanganate solution it is necessary to pass a current of air through the reaction flask to avoid the oxidation of the non-lactic acid substances which interfere with the reaction. The absorption tube must be maintained at 18°C during the destillation and the titration of the bisulphite binding aldehyde at 4°C. When the sample contains more than 5 mg it is useful to work with greater quantities of the bisulphite. More permanganate is consumed when the lactic acid concentration is higher. The sensivity of the method permits the titration of 0.04 mg to 5 mg of lactic acid in the sample. The calculated error of the method gave 0.018 % and the normal values for blood determined in 20 human cases averaged 10.30 mg per 100 ml (Table VI). MENDEL and GOLDSCHEIDER'S method was modified in the following details: Somogyis deproteinization was performed instead metaphosphoric acid as in the original method; to avoid the evaporation of the acetic aldehyde during the heating time with sulfuric acid a special glass stopped tube is proposed (Fig. 2). The reaction with sulfuric acid and veratrol is performed in an ice bath. Blood proteins precipitants were tried and Somogyi's lattest tecnic showed better results (Table V). Colorimetric readings were done in the PULFRICH photometer using filter S 53 and a 10 mm cup. The method is accurate within an error of 0.23 % and samples of 5 to 70 microg. could be easily determined. Normal values for human blood averaged 10.78 mg per 100 ml. More accurate results were obtained with the technic of MILLER & MUNTZ. Slight modifications were introduced: deproteinization with copper sulfate and sodium tungstate; satured p-hydroxydiphenyl solution according to KOENEMANN which is stable for 5 months when stored in the ice-box. Using the PULFRICH step-photometer the error is 0.17% with samples varying from 0.1 to 10 microg. of lactic acid. The filter employed was S 57 with the 5 mm cup. The method was adapted to 0.1 ml of blood. Normal values for human blood gave an average of 10.58 mg per 100 ml.

Preparo de filmes-suporte para microscópio eletrônico

Working with low voltage microscope (R.C.A., EMC-2, of 30KV.) the authors verified that parlodion and Formvar films are quickly destroyed by intense heating under the electron beam. They have tried to employ oxide films, as Al2O3 and SiO, more resistant to heat. Al2O3 films are prepared by anodic oxidation of thin aluminium sheets, under 8 to 10 volts in a 3% ammonium citrate solution and subsequent aluminium dissolution in a O.25% HgCl2 solution. These films are very suitable when prepared with highly pure aluminium of extremely homogeneous surface. Best results were obtained with SiO films, evaporated in high vacuum over Parlodion films mounted on metallic grids. Employing 1 or 1.5 mg of SiOm highly homogeneous and resistant films are obtained, having little inferior transparence than the Parlodion ones. Pure SiO films (1.5 mg) are obtained by elimination of the Parlodion under slow heating until 250°C; they are greatly transparent but little resistant to water, thus beeing indicated in dry preparations. For particles which deposite in a chain-like form around thin fibers, the authors employ the mounting on Parlodion fibers, obtained by heating Parlodion films on microscope grids about 190°C.