Search

Information on soil nutrition level or soil pollution level can lead to the establishment of some recommendations or a strategic decision-making program for the reference area development. The specific soil analysis is essential both from an economic point of view and from an environmental point of view. To achieve an adequate management of the nutrients into an agricultural field, it is necessary to conduct an agrochemical study at an interval of 3-5 years, in which, the relevant agrochemical indicators for the evaluation of the nutrient supply state must be analysed, to determine fertilizer doses and/or recommended amendments for the expected crops. The agrochemical study must contain the analysis bulletin that provides the following information: pH value, humus and total nitrogen content, phosphorus (P) and potassium (K) content, C/N ratio (carbon / nitrogen), nitrogen index (NI), as well as the main microelements. [ABSTRACT FROM AUTHOR]

The proposed article sets out the results of the finite element structural analysis for the open and compartmentalised watering furrow equipment (OCWFE). It uses a 3D structural model with 3D finite elements. The analysis set out in the article is made in order to determine the field of relative displacement and equivalent stress in the load-bearing structure of the OCWFE. The structural model is generated in CAD-CAM. For the structural analysis, it is necessary the CAE model, which is obtained from the CAD-CAM model, mainly by eliminating gaps and interferences, but also by the techniques of realizing the contact between the components of the assembly and a careful mashing of the structure. The structural model thus created is supported and loaded in accordance with the experimental results from the literature. The relative displacement field and the equivalent stress field within the resistance frame of the OCWFE is obtained following the linear static analysis. The field of relative displacements is used to assess the effects on the quality of the work performed. The equivalent stress field is used to estimate the safety factor of the structure, by reference to the flow stress of the material from which the structure is built. [ABSTRACT FROM AUTHOR]

The paper presents the results of research on the performance of linear electro-hydraulic servomechanisms with stepper motor, evaluated by mathematical modelling and numerical simulation with the AMESIM software package. These servomechanisms have a great potential for application, including for agricultural technical equipment. Servomechanisms of various types are used for the rapid and high precision operation of the various systems. In practice, electro-hydraulic servomechanisms have been required in the case of the systems requiring high forces or moments. These equipment are automatic hydraulic tracking systems and can be analysed with methods specific to automatic systems. The paper contains a structural description of an electro-mechanical servomechanism with stepper motor, its operation, mathematical model and its performances obtained by numerical simulation. The mathematical modelling of the electro-hydraulic servomechanism is based on the relations between the input sizes and output sizes of the equipment in its structure as well as the connection relations between these equipment. Based on the obtained results it is demonstrated that the analysis and synthesis of electro-hydraulic servomechanisms with stepper motor can be determined by numerical simulation using the AMESIM simulation software. [ABSTRACT FROM AUTHOR]

This article presents results obtained by the author in an attempt to introduce new parameters that influence the working process of agricultural soil working machines, in the classical formulas that mathematically model the tillage draft force. This article naturally introduces soil moisture. To introduce soil moisture into the calculation formulas of the tillage draft force, other physical parameters affected by soil moisture were used: density, cohesion, adhesion, etc. In this article, is explicitly describes, only the variation of soil density with its moisture. Considering some phenomena such as soil swelling or shrinkage, required the development of an adequate mathematical model of the expression of the density of soil-water mixture, concerning the concentration of water and the densities of dry soil and water. The final formulas obtained are tested to experimental results from the literature. Finally, the author sets out his opinion regarding the use of the results in design calculations and regarding the elevation to the rank of physical law of a mathematical model represented by a formula with a large number of parameters, which in turn are still dependent on many others parameters. [ABSTRACT FROM AUTHOR]

The article presents a possibility of applying the techniques specific to the drones (UAV) in order to estimate the efficiency, and optimize the windbreaks (vegetative barriers, forest curtains).In the first part the article presents a variant of determination of the dynamic and optical porosities of forest protection curtains using one or two drones simultaneously. In the second part, ascertaining some language inaccuracies, it observes that the issue of the efficiency of the forest curtains became a problem of mitigation of wind intensity. Finally, the last proposed application shows that using the drones, you can estimate the protected volumes behind the curtains, basically giving up the optical porosity. In order to achieve these applications, there is an essential condition: records of the magnitude of the wind speed and of the coordinates must not be excessively affected by the wind. [ABSTRACT FROM AUTHOR]