SOLIDWORKS 3D PARAMETRIC MODELLING TECHNIQUE FOR ROOT CUTTING EQUIPMENT DECLINING GROWTH OF SHOOTS IN ORCHARDS

This work was focused, by using computer aided engineering application (SolidWorks) and structural simulation (SolidWorks SIMULATION), on obtaining a technical and economic strength indicator used in the analysis of metallic material choice from which is made active body large diameter disc knife type, that equips the technical equipment for soil tillage on trees row, while cuttings root for moderating growth of shoots and precision foliar fertilization. For this purpose, on the 3D parametric modeling were selected from the software library various metallic materials, followed by finite element analysis (FEA) which was carried out to simulate the distributions of stress and strain on the body active. Based on the resulting data, were determined the reports price- coefficient of resistance for the materials analyzed. Comparing these indicators led to the selection of a material that has high resistance under a price as low as possible. Analysis based on technical and economic choice of a metallic material reduces the time validation of the design, by eliminating the realization and physical testing, and allows management to determine the existing resources in the company in order to use their total for achieve economic and financial results as high

Evaluation of transfer and bioaccumulation factors of heavy metals in different parsley samples

Heavy metals transfer factors help to observe metals impact on agricultural products (vegetables and/or fruits) to evaluate different bioaccumulation scenarios to interpret available experimental results and for designing fingerprints or bioaccumulation maps. The aim of this study was to evaluate the transfer factors (TF) of some heavy metals (HMs) including (Fe, Mn, Zn, Cu, Ni, Pb and Cd) from soil to root and leaves of parsley samples cultivated on polluted and nonpolluted areas and to identify the fingerprint of transferred metals. The heavy metal (HM) content was analyzed using Flame Atomic Absorption Spectrometry (FAAS) technique. The bioaccumulation factor (BF) and TF in parsley samples were used for obtaining the fingerprints (HMs bioaccumulation maps) of parsley samples

Uticaj vlažnosti zemljišta na energiju procesa u poljoprivredi

This article exposes the results related to one of the issues left open after a series of articles mentioned in the bibliography, which occurred in the years 2011-2013. A series of articles that were mentioned before reconsidered the workflow optimization problem of agricultural aggregates developing fundamental calculation in the 1950-1980s literature. Some open problems still arise from the theoretical and empirical reasoning. A solution to one of these problems is given in this article. The solution exposes an input mode of the soil moisture influence on the existence and quantification of possible optimal point in the space energy workflow of agricultural aggregates.U ovom radu su prikazani rezultati istraživanja u jednoj oblasti koja je ostala otvorena i posle serije izvora pomenutih u literature, a dobijeni su u periodu 2011-2013. Pomenuti radovi razmatrali su ponovo optimizaciju toka radnih procesa poljoprivrednih agregata razvijajući fundamentalni obračun u periodu 1950 - 1980. Neki otvoreni problemi i dalje nastaju iz teorijskih i empirijskih razloga. Rešenje jednog od ovih problema je dato u ovom radu. Rešenje prikazuje unos uticaja vlage u zemljištu na postojanje i kvantifikaciju moguće optimalne tačke u prostoru energetskog toka poljoprivrednih agregata

A mathematical model for the accumulation of fatigue in bars subjected to lateral vibrations

The article presents a mathematical model for the phenomenon of fatigue accumulation in the slender bar subjected to lateral bending. The model is based on the Euler-Bernoulli type bar, a bi-linear elastic-plastic model and, for simulation of fatigue, a system of equations describing the decrease resistance parameters of the material: the ultimate strain and stress. In the article is exposes the bar response to two types of dynamic loads, as well as a fatigue test simulating process using the proposed model, which results in the Wöhler diagram of the material for the bending vibrations. The conclusions outline the outlook of the model as well as its shortcomings. The author expounds the advantages of the model, but the reader is also challenged to reflect on the opportunity of using mathematical models of great complexity

Drones and windbreaks

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

Intensity of soil erosion in Romania, predictions in time and space, European and indigenous perspectives

The subject of this article is the estimation of the water erosion given by different sources during the history of over one hundred years of observations. The differences between the estimates made at the near times, or at the appreciably different times, are viewed for the approximation, of the random behaviour of the factors involved in the water erosion process, but also for the changes (apparently in time) of the intensity of the factors involved. The so-called climatic changes, characterized mainly by apparently (at the scale of human life) nonperiodic changes of meteorological factors, produce effects including on the factors involved in water erosion, which are not in the category of meteorological parameters, such as soil erodibility, but also the geometric parameters of the slopes. By default, there are effects in vegetal cover and management parameters. From this point of view, the influencing factors of mathematical models for predicting water erosion should be recalculated or periodically reviewed

Soil moisture influence in the soil tillage operations

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