INMATEH - Agricultural Engineering

6

Authors: Dumitraşcu A., Manea D., Căsăndroiu T.

The quality of phytosanitary treatments performed in crops is largely determined by how substances are sprayed on the plant, by the droplets size, the coverage of the plant and the reduction of drift phenomenon. The main elements responsible for the quality of working process of phytosanitary treatment machines are the nozzles, which are the principal elements of any sprayers. This explains the great variety of spraying systems. In this paper are detailed some theoretical issues regarding the spraying process through nozzles as the basis for experiments to be carried out using the machine for high precision application of phytosanitary treatments in orchards, MSL. Analysis and modeling of this process is achieved using as main working instrument the dimensional analysis theory.

6

Authors: Paraschiv G., Manole C.

The paper explains, on the basis of the minimum power principle, the phenomenon of layering a mixture of material particles (especially seeds of cereals) maintained under an oscillating motion, with or without the action of an air stream. This phenomenon of separation into fractions is also generalized on a mass of particles with the same specific weight, but with different sizes, an untreated aspect, in this form, in the specific literature.

6

Authors: Marcos V. G. Silva, Celina de Almeida, Antonio Carlos Loureiro Lino, Inácio M. D. Fabbro

Three-dimensional survey of irregular, as well as regular solids has recently received significant attention from the scientific community due to its wide range of applications, including topics in agricultural engineering as plant-machine mechanical relationship. The pertinent literature discloses several methods and techniques to carry out three- dimensional measurements associated to a wide variety of cases. Moiré techniques are included in a group of non-contact and non-destructive methods based on the Moiré phenomena which generate optical fringes onto the tested body surface. Moiré methods require simple and low cost experimental setup, yielding accurate results when compared to other measuring systems. This work was focused on the projection Moiré technique with phase shift, employing two types of optical grids named Ronchi and a sinusoidal one. Metrological errors of tested techniques as compared with the Moiré method have been determined as well. This work demonstrated the best performance of grid frequency variation through several experiments applied to irregular solids shape determination as fruits. Body volumes were compared with conventional techniques as water immersion; meanwhile linear measures were compared with reading caliper results. The application of free software such as ImageJ, RisingSun Moire, Scilab / SIP and routines was considered very useful to reach the final results.

8

Authors: Ganeva D., Sirakov K., Mihov M., Zahariev S., Ivan Palov

The study has found a continuing beneficial impact of electromagnetic treatments on seeds of Bulgarian tomato varieties: Milyana, Plovdivska karotina, Vodoley F1, IZK Alya and Ideal after 365 days storage to sowing at a voltage between the electrodes U=12 kV and duration of impact =35 s. The germinating energy and laboratory germination increase compared to that of control seeds of 1.25 to 15%.

8

Authors: Lyashuk O.L., Rogatynsky O.R., Serilko D.L.

A mathematical model of the vertical screw conveyer loading has been proposed. Algorithm of solution of the differential equations with partial derivatives of the bulk-cargo medium movement in the screw channel has been developed. Taking advantage of the proposed model it makes possible to develop new designs of the screw conveyer intake devices and to interpret their efficient parameters.

8

Authors: Moiceanu G., Voicu Gh., Paraschiv G., Dinca M., Chitoiu M., Vlădut V.

An important component of modern society is represented by renewable energy. This type of energy can be obtained through energetic plant processing, wind energy, solar energy, etc. Taking into consideration the potential of energetic plants regarding ensuring a sustainable future from an energetic point of view, this paper presents a review on the way in which mechanical properties influence the processing stage. Considering that the equipment used for this process is in continuing development, knowing the energetic plant stem mechanical properties is a major component in creating and developing these machines. Energetic plant mechanical properties are important data for mathematical modelling of the processes to which the stems are subjected to. Studying shearing resistance, compression/stretching resistance, cutting resistance, as well as the elasticity module, we can see that all the data lead to creating an adequate design for the equipment. The main objective of this paper is to create a synthesis regarding energetic plant mechanical properties.

10

Authors: GuohaiZhang, Ruicheng Du, Peisong Diao, Duanyang Geng

An ecological soil planting method was proposed for the annual double cropping of wheat and maize with a five-year cycle. This method is suitable for Huang-Huai-Hai Region and aims to address the problems of reduced crop yield and soil crust as a result of soil and water loss, deteriorated land fertility, and protective tillage in intensive cultivation. Moreover, the planting specifications of the annual double-cropping rotation patterns of wheat and maize were unified, and the key agricultural equipment was designed for full mechanization. Research results on the test demonstration base showed that the return of straw to the field and scientific fertilization can limit the emissions of harmful gas and the use of fertilizer. Furthermore, these steps can enhance ecological agricultural production. The return of straw to the field and suitable cultivation can increase the content of organic matters in soil, improve the aggregate structure, and enhance soil fertility. Finally, the implementation of the ecological fertile soil planting technique can overcome the disadvantages of intensive cultivation and protective tillage, thereby facilitating stable and high crop yield.

10

Authors: Hevko. I.B., Dyachun A.Ye., Hud V.Z., Rohatynska L.R., Klendiy V.M.

The aim of the research is to analyze the influence of pulse forces on non-linear torsorial vibrations of a screw conveyer. The methodology is based on the combination of the methods by Bubnov-Halorkin and Van der Pol. With the help of this methodology we have developed the so called equations of a standard form for the case of pulse forces action. A mathematical model of the torsorial vibrations of a screw conveyer under the influence of pulse forces is presented. It has been determined, that there is a jump pattern of change of the amplitude-frequency characteristics of the torsorial vibrations of a screw conveyer. Resonance torsorial vibrations of a screw conveyer under the influence of pulse forces have been considered. Torsorial vibrations of a screw conveyer have been investigated in case, when the moment of resistance forces is proportional to the relative angular velocity, and the moment of pulse forces is approximated by a non-linear function. It has been determined, that in such a case the influence of pulse forces becomes apparent only in the change of frequency of the vibrations of a screw conveyer. The amplitude-frequency characteristics of the torsorial vibrations of a screw conveyer of different geometrics have been presented.

12

Authors: Deng Jifeng, Ding Guodong, Gao Guanglei, Gao Lin

Farmland shelterbelts can yield maximum ecological benefits with the smallest occupied area of forests and result in sustainable use of farmland resources. Rapid and efficient planning of farmland shelterbelts at various scales is becoming an urgent task in ecological landscape design. Until now, the problems in studies on farmland shelterbelts combined with wind erosion models are associated with conflicts between scientific and practical requirements. Based on previous research results, a case study was conducted in Yanchi County in north-western China. The primary objectives of this study were to use a new method for the arrangement of tree species and to investigate the effects of sand prevention. In addition, changes in the trends of the input parameters under multiple wind erosion events were analyzed and tested. The results indicated that under a single arrangement of tree species, better shelter protection was provided within the shrub shelterbelt or outside the arbor shelterbelt forest. Under a different arrangement of tree species, shrubs arranged with arbor belts gave little protection on the leeward side. Arbor trees arranged with shrub belts could effectively prevent sand from the windward side, while low trees in the upwind direction provided limited protection. Cumulative percentiles of sand displacement showed that under different arrangements of tree species, the sand prevention benefit was better than that of a single tree species. In addition, the experimental error was less than 3.00% and there was close correlation between percentiles of sand displacement under multiple wind erosion events, indicating a preferable simulation effect.

12

Authors: Jin C., Wei J., Sun H., Yin Y.

To ensure riding comfort, vibration generated by engine, drive system and ground need to be considered in designing an agricultural vehicle. This study examines multi-body dynamics model of an agricultural vehicle, and focuses on the distributed electric-drive agricultural vehicle. To simulate the response of an electric-drive agricultural vehicle to vibrations excited by the drive motors, engine and road roughness, this study proposes a vibration model of a distributed electric-drive agricultural vehicle that has 11 degrees of freedom and coupled excitation sources. The model was derived from vehicle dynamics equations and solved numerically employing fast Fourier transform. The model was validated in experiments on a real distributed electric-drive agricultural vehicle. Simulations and experiments showed that the amplitude of low-frequency vibration of the cab was increased by simultaneous excitations, which could not be ignored. This result is useful for the design of the suspension component and overall design of agricultural machinery.