Resumo em Inglês:

ABSTRACT The most important parameter in terms of material mechanical behavior knowledge is the modulus of elasticity, being traditionally obtained through destructive tests. The objective of this study is the verification of the potential use of the particle image velocimetry technique (PIV) as a tool to obtain the modulus of elasticity in sawed wood samples (Pinus oocarpa and Eucaliptus grandis) and wood panels (Plywood, LVL and OSB). The PIV technique has as characteristics the low cost of equipment, fast results, no need for contact with the object tested, accuracy and possibility of application in the field. The application of the PIV technique occurred during the static bending tests where the deformations were also measured with a dial indicator (conventional method), thus obtaining comparative measurements. From the load values applied by a universal test machine and deformation values obtained by the dial indicator and PIV techniques, it was possible to calculate the modulus of elasticity through both methods. With the “Student's t” statistical test application with significance level of 1%, it was verified that the modulus of elasticity found by the PIV technique and the dial indicator were statistically equal. Average values for the modulus of elasticity found were respectively for the use of the conventional method and for the PIV method the values of: 13,077 and 13,027 MPA for Eucalyptus grandis; 6,171.6 and 6,418.8 MPa for Pinus oocarpa; 10,481.2 and 11,094.3 MPa for plywood; 8,687.4 and 10,261.0 MPa for the LVL; and 2,480.1 and 2,899 MPa for the OSB. It was concluded that the PIV technique is capable of measuring modulus of elasticity values with similar precision to the test techniques traditionally used for this purpose.

Resumo em Inglês:

Abstract The electronic monitoring of physiological responses is essential for managing animal production systems considering market demands for animal welfare. The objective of this study was to design, build, and test an electronic monitoring system, with recording and wireless transmission capability, for measuring the heart rate and skin temperature in small ruminants. The system had two components: a mobile base unit, mounted on the animal under study, and a fixed base unit. Wireless communication between the mobile and fixed units was performed using a Xbee Series 2 radio frequency transceiver whereas data were recorded and transferred to a secure digital card in the mobile unit. The device was mounted in Santa Inês crossbred sheep using reference equipment while the animals were restrained in steel cages. Subsequently, the device was validated in free-living Dorper sheep in two collection periods (morning and afternoon). The results indicated that the monitoring system accurately measured physiological responses and efficiently recorded and transmitted data, particularly heart rate data. However, one of the limitations was low energy autonomy.

Resumo em Inglês:

Abstract The aim of the present research was to propose a bioclimatic mapping to classify the thermal comfort and discomfort of rural workers within the state of Minas Gerais, considering historical and future scenarios. Monthly historical series (1976-2014) of minimum, mean and maximum temperature-humidity index (THI), determined through the values of air temperature (minimum, mean and maximum) and relative humidity from 48 weather stations located in the state of Minas Gerais were used to analyze the trends through Mann-Kendall and linear regression assays. The bioclimatic mapping of human comfort, obtained via geostatistical analysis, was developed as a function of the minimum, medium and maximum THI for the historical period (1976-2014) and future scenario (2024). Results indicate an overall trend of increasing in thermal discomfort conditions throughout the mesoregions of the state of Minas Gerais during the weather seasons, being more incisive in summer and spring.

Resumo em Inglês:

Abstract This study was carried out with the objective of assessing grain yield, economic analysis and energy balance of three sunflower genotypes with and without irrigation. The experiment was installed in the Experimental Farm of the Faculty of Agrarian Sciences of the Federal University of Grande Dourados in the 2011/2012 and 2012/2013 harvests in Dourados-MS, Brazil. The experimental design used was a random complete block design with subdivisions, with and without irrigation (plots), with three genotypes (subplots) and four replications, constituting 24 plots. There were no differences in productivity among the genotypes. The irrigation increased the operational cost of the sunflower crop production, but it did not economically obstruct the activity, due to the increase of productivity of 74.5% and 30% in the harvests of 2011/2012 and 2012/2013. The energy ratios of the sunflower crop were not altered by irrigation, equal to 5.7 and 8.7 in the harvests of 2011/2012 and 2012/2013, respectively.

Resumo em Inglês:

Abstract The uniformity of water application is an important factor in the evaluation of sprinkler irrigation systems. This uniformity depends on the type of sprinkler and its operating conditions, such as the arrangement and spacing between the sprinklers in the area; velocity and wind direction during the period of water application and the pressure variation of the irrigation system. The objective of this study was to model, analyze and compare the structure of spatial dependence, as well as the spatial variability of the water depths applied by a sprinkler irrigation system with compensating and non-compensating sprinklers, using geostatistical methods and measurements of accuracy or similarity between the applied water depth maps. The experiment was carried out in an agricultural area, in the city of Cascavel-Paraná-Brazil. A total area of 10 × 10 m was used, with 04 compensating and 04 non-compensating sprinklers installed at a height of 1.5 m. For each type of sprinkler, water levels were measured in 100 collectors spaced 1 × 1 m in the study area in 32 trials. On each test sprinkling was carried out for one hour. The conditions of wind, temperature and air humidity were evaluated at the beginning of each test and at 10-minute intervals with a climatological station. As the geostatistical analysis showed the existence of directional trends, the coordinates were incorporated as covariates to the linear spatial model in the study of the spatial dependence of the average depth of the irrigation water for the two types of sprinklers. The spatial dependence structure that best fits the data when using the compensating sprinklers was the Gaussian model and when the non-compensating sprinklers were used, it was the exponential model. The spatial variability maps of average irrigation water depth (mm) of the trials, obtained by universal kriging, revealed that for both sprinklers there was an increase in the mean level average values in the northwest-southeast direction (135° in the azimuth system) in the area under study, influenced by wind direction and velocity during the execution of the experiment.

Resumo em Inglês:

Abstract This study aimed to evaluate Pome type bananas grown under different irrigation systems. Seventy-two treatments were used in a factorial 3×2×12 scheme, where factors consisted of three irrigation systems (under-tree sprinkling, micro-sprinkling, and dripping), two cultivars (‘Prata-Anã‘ and ‘BRS Platina’), and twelve evaluation periods (months). The treatments were arranged in a completely randomized design with five repetitions. During the third production cycle, plant phytotechnical and physiological traits were evaluated in different months at five different times of the day. The results showed no significant interactions between cultivars and irrigation systems. All the assessed traits varied for each irrigation system, except for plant yield. The banana plants presented higher vigor and a larger number of hands when grown under conventional sprinkling and micro-aspersion systems, regardless of the cultivar. The cultivar ‘Prata-Anã‘ has larger leaf areas and number of hands, regardless of the irrigation system. Moreover, plants irrigated by dripping exhibited higher leaf temperatures, higher transpiration rates, and lower instant water-use efficiency. When irrigated by micro-sprinklers, the plants displayed greater water-use efficiency. As leaf temperature rose, perspiration increased linearly, while the instant water-use efficiency decreased linearly.

Resumo em Inglês:

Abstract Sugarcane pre-sprouted plantlets (PSP) production system is an innovative method to enhance crop multiplication rate. Determination of crop evapotranspiration (ETc) is crucial for water requirement identification throughout the plant cycle for irrigation management. ETc can be satisfactorily measured by weighing lysimeters. The objective of the study was to construct and calibrate three low-cost weighing lysimeters to measure ETc of PSP. The built lysimeters had 0.6909 m2 area (1179 mm × 586 mm), with 400 mm depth supported by 3 load cells. Lysimeters calibration showed excellent precision measurements, due to high linear correlation (R2 = 1.0000) between electric signal and equivalent mass, high accuracy, confirmed by mean absolute error between 0.0272 and 0.0382 mm, mean square error between 0.0011 and 0.0024 mm2 and Willmott's index of agreement (d) equal to unit. Maximum hysteresis (0.1951 mm) and hysteresis at full scale (0.4492%) did not compromise the evaluations. Daily ETc measurements showed variation of 0.27 mm among lysimeters and were coincident with daily course of reference evapotranspiration (ETo). The cost of the equipment was low, except for the data acquisition system. Therefore, lysimeters presented low cost and were adequate to measure ETc of PSP in greenhouse-grown.

Resumo em Inglês:

Abstract Given the lack of studies on subsurface drip irrigation in sugarcane plantations, there has been a growing demand for such information, mainly regarding soil solution profile and availability to plants. Thus, this study aimed to evaluate the effects of soil-water solution distribution on qualitative and quantitative traits of sugarcane irrigated by subsurface drip irrigation at two flows (1.6 and 3.5 L h−1). For each application rate, four PVC containers (500 L) were used and filled with sandy soil, where a set of 36 TDR probes was installed. Drippers were placed at a depth of 0.30 m. Irrigation was managed based on TDR daily measurements, maintaining soil moisture within the root zone at field capacity. Sugarcane variety used was RB 845210, being fertigated according to soil chemical analysis. The results showed that the distribution of soil-water solution became stable at different depth layers during applications, highlighting a relationship between soil solution storage and wetted soil volume. Moreover, irrigation flow rates had no effect on the distribution of water and nutrients throughout the soil profile, neither crop yield, technological quality nor root density.

Resumo em Inglês:

ABSTRACT The performance of the tractor-seeder can be influenced by factors related to the seeder, as loads and crop. The aim of the present study was to evaluate the performance of tractor-seeder at sowing in the corn crop in function of the fertilizer systems (at presowing and at sowing) and those intercropping of crops (corn + bean-Stizolobium deeringianum, corn + bean-Cajanus cajan and corn + bean-Dolichos lab lab). The experiment was carried out at FCAV-UNESP with totally randomized delineation, on factorial scheme (2x3) with four repetitions. The use of fertilization during the pre-sowing resulted in greater displacement speed and effective field capacity in the corn sowing operation, without changing the distribution of corn seeds; however, it demanded more power and volumetric and weight hourly consumption of the tractor fuel.

Resumo em Inglês:

ABSTRACT The aim of this study was to evaluate the spectrum and the velocity of droplets produced by nozzles with and without air induction, under different pressures and flow rates. The experiment was conducted in a completely randomized design with five replications, in a factorial 2 x 3 x 3 (two spray nozzles, three flow rates and three operating pressures). The spray nozzles with and without air induction of the Hypro manufacturer (GA and VP) were evaluated, with nominal flow rates of 0.76; 1.14 and 1.51 L min-1 and pressures of 200, 300 and 400 kPa. The spectrum and velocity of the droplets were determined directly, using a Visisize Portable P15 (Oxford Lasers, Imaging Division). The pressure increases further reduction of the VMD and the relative amplitude, and increases the droplet velocity. The droplets generated by the spray nozzles with air induction showed on average amplitude 1.54 times higher than the droplets generated by spray nozzles without air induction. The droplet velocity showed little variation between the nozzles with and without air induction with the same pressure and flow rate, however, spray nozzles with larger flow rates and pressures produced droplets with higher velocities.

Resumo em Inglês:

ABSTRACT Several equipments are used in the application of agrochemicals by small scale farmers, with emphasis on the knapsack hand sprayer due to the low cost of acquisition and viability of use in different operating conditions. Although it is an equipment widely used, few studies have been developed in order to ascertain its functional characteristics. This study has the objective of presenting a methodology to measure the effort to which the operator is subjected in the activation of the pumping lever of knapsack hand sprayer verifying if these machines fit within the limitations foreseen by the Brazilian laws and international regulations. The methodology used was adequate to measure the operator's required efforts for the activation of knapsack hand sprayer. All sprayers tested with water have achieved satisfactory results by national standards, but only two by international regulations.

Resumo em Inglês:

ABSTRACT The peanuts harvesting mechanization is affected by the soil physical characteristics and it may increase the losses due to the production of pods in subsurface. The objective of the experiment was to identify the clusters through multivariate exploratory approaches from similarity in six soil textures (very clayey, clayey, silty clayey loam, clayey loam, sandy loam and sandy) in the state of São Paulo, Brazil, determining the main agronomic variables that most influenced the clustering division to assist the decision-making process in peanuts mechanized harvesting. The data were analyzed by the multivariate exploratory that is performed to simplify the description of a set of interrelated variables, using: yield, maturity, soil and pod moisture content, windrow width and height, visible and invisible digging losses, and gathering losses, as agronomic indicators of quality. The low and high clay content were grouped into clusters I and III, respectively, according to the agronomic traits of the peanut crop. The principal components analysis (PC) allowed a single distribution of accesses since only two eigenvalues were higher than “one”: the highest eigenvalues of 4.51 and 1.79, resulted in a Biplot that explained 70% of the original variability, 50.11% and 19.89% of which in the PC1 and PC2, respectively. The multivariate analysis indicated that high peanut yields in soils with low clay are correlated with the losses during the peanut mechanized harvesting operation.

Resumo em Inglês:

ABSTRACT In Brazil, a large portion of peanut production is found under conventional soil preparation. Due to the fact that there is a lack in studies related to the cultivation of peanuts in conservationists soil preparation, mainly in the field of losses and mechanized harvesting. Thus, it was aimed to assess the quality of digging and gathering operation of peanut, based on losses, using statistical process control techniques in two tillages. The sowing was carried out under conventional and conservationist preparation, revolving only the sowing line. Losses were evaluated in the digging and gathering operation, being that in the gathering it was evaluated the harvest losses in three displacement speeds (4, 6 and 8 km h-1) in two tillages. The quality of the process was affected by the soil preparation based on the visible and invisible losses, respectively. Regarding the gathering, the conservationist preparation, it was unstable in all indicators, whereas in the conventional preparation it was noticed reduction of the variability for all the displacement speeds. The peanut sowing under conservationist preparation provided a better quality digging. In contrast, the gathering of pods in areas under conventional tillage showed a better quality of the operation.

Resumo em Inglês:

ABSTRACT Spatial variability depends on the sampling configuration and characteristics associated with the georeferenced phenomenon, such as geometric anisotropy. This study aimed to determine the influence of the sampling design on parameter estimation in an anisotropic geostatistical model and the spatial estimation of a georeferenced variable at unsampled locations. Datasets were simulated with geometric anisotropy, considering five values for the anisotropic ratio (1, 2, 3, 4, 5), and three sampling designs: lattice, random and lattice plus close pairs. The simulation results were used as a reference to select anisotropic models to describe the spatial dependence structure in chemical soil properties. For each dataset (with either simulated or chemical soil properties), the values of the georeferenced variables at unsampled locations were estimated by kriging, considering estimated isotropic and anisotropic geostatistical models. The choice of the sampling design influenced the spatial estimation of the georeferenced variable and the quality of the estimation of the geostatistical anisotropic model. The incorporation of geometric anisotropy in the spatial estimation of simulated data sets and soil chemical properties produced differences in the spatial estimation and improved the level of detail of subregions in thematic maps.

Resumo em Inglês:

ABSTRACT The aim of this study was to evaluate the behavior of an anaerobic reactor of packed-bed and continuous flow, in relation to the biogas and methane production and the removal of organic load, from the wastewater of cassava starch extraction. For this purpose, were tested, in a reactor with a useful volume of 2.82 L and support mean of polypropylene filled with polyethylene foam, the organic loading rate (OLR) of 2.5, 5.0, 8.0 and 10.0 g L-1d-1. It was evaluated the removal of COD, the pH, the VA/TA ratio, the biogas and the methane production. It was concluded from this study that it is possible to produce biogas with methane percentages higher than 80% (maximum) and remove the organic load more than 90% under the tested conditions. In relation to stability, the reactor can be considered stable for the parameters, pH, the relationship between volatile acidity and total alkalinity and organic load removal. The best results in relation to the average volumetric biogas production (0.174 and 0.311 L g COD-1) were obtained for the higher organic loading rate (of 8 and 10 g L-1d-1, respectively) and the observed tendency is that with the increase of the organic loading rate, the specific biogas production will increase as well as the specific production of methane.

Resumo em Inglês:

ABSTRACT Changes in the Brazilian Forest Code (BFC) have soften the criteria for recovery and conservation of permanent preservation areas (PPAs), enhancing processes related to surface runoff. The aim of this study is to understand the effects of changes in PPA classification criteria established by BFC of 2012 to the detriment of BFC from 1965 considering the surface runoff response in the basin draining the upper Marrecas River valley in the flow peaks. The HEC–HMS model was used to simulate flow peaks considering three land-use scenarios, representative of the current use, adapting it to PPAs fitted to the BFC of 1965 and 2012 and seven precipitation return periods. In the proposed scenarios, the use of BFC of 2012, to the detriment of that from 1965, would imply a PPA reduction from 44.5% to 13.7%, resulting in a 22.1% increase in the average flow peaks, not representing, however, a significant reduction in the flow peaks when compared to the scenario representing the current land use. Therefore, when compared to BFC of 1965, in the Brazilian new Forest Code PPAs were reduced by 69.2%, increasing peak flows by up to 30.7%, thus minimizing the legal possibilities of flood mitigation to the urban perimeter of Francisco Beltrão, Paraná State, Brazil.

Resumo em Inglês:

ABSTRACT This study aimed to evaluate the energy efficiency of a center pivot irrigation system operating in a terrain of variable topography. Values of Pumping Energy Efficiency (PEE), Supply Energy Efficiency (SEE), Global Energy Efficiency (GEE) and Specific Energy (Es in kWh m-3) computed at 18 different angular positions of the lateral line were used as energy efficiency indicators. An ultrasonic flow meter, digital pressure transducers and a power quality analyzer were used in order to evaluate hydraulic (total system flow-Q and total dynamic head-TDH) and electrical parameters (active electrical power - AEP) of the center pivot pumping unit that were required for evaluating the selected energy efficiency indictors. Topographic elevations of the water source, the pumping unit and of the center lateral line were also determined. For the center pivot lateral line, it was necessary to determine, at the 18 angular positions considered, the altitude of the track of each center pivot support tower. Results indicated that currently, even after more than 10000h of use, the center pivot system operates with satisfactory energy efficiency, as indicated by an average GEE value equal to 42.5%, that is classified as “good”. Statistical analysis indicated that the topographic disposition of the center pivot lateral line, as characterized by a uphill or downhill disposition, resulted on different PEE, SEE and GEE values, while the average Es value (0.42 kWh m-3) was not affected by the lateral line disposition.

Resumo em Inglês:

ABSTRACT Harvesting fruits and vegetables has been a challenge. Mobile platforms for harvesting vegetables and fruits have been used, but with some limitations, such as their applicability for a certain time of the year and for a specific crop. A mobile platform was initially developed for harvesting fresh market tomatoes, mainly staked in Brazil. However, after field trials, many problems were identified, such as crop use limitation and machine structure problems. Therefore, the initial project was reformulated to assume different functions, with a retractable and smaller frame and the possibility of adding on other devices, expanding crop harvest and farm use. The concept of a hybrid vehicle with one electric power generator to drive all four wheels with electric motors was kept. The main goal of this article is to describe the development of the mobile platform machine structural details and integration of electrical, hydraulic, and mechanical project and field tests performed in a commercial orange orchard, comparing harvest types, evaluating yield and machine performance. Tests with the mobile laboratory prototype show its potential application to assist harvest and to other farm operations, especially due to its mobility. Harvest productivity through machine was higher, though not significantly different from manual harvest.