INMATEH - Agricultural Engineering

6

Authors: Shvedik M.

In the article the results of analysis of work process of seeding furrows embedding and compaction of soil by the conical roller which is set at the angles α to direction of furrow, and also analytical expressions for definition of resistance force of the roller by moving and lateral force which provides a self-cleaning of soil, which sticks to its surface, are given.

8

Authors: Fechete Tutunaru L. V., Nagy E.M., Coţa C-tin

The geometry of the cutting edge or of the surface contour is of great importance in minimizing the energy required for the mechanical processing operations. The vast majority of the research conducted so far in the soil processing field focuses on macro geometry of the tools without taking into account the geometry of the cutting edge. This paper presents the results of experimental research regarding the influence of the modification by wear of the constructive parameters of the cutting edge corresponding to the tillage tool on the economic indicators in the working process. Thus was established a mathematical model that highlights the correlation between the processed surface and the linear wear of tools, with which the average area that a tool can process until it reaches a wear limit value, can be determined.

8

Authors: Marin E., Pirnă I., Manea D., Matache M., Popa L.

Irrigation and proper fertilization humidity and climate control are key factors in creating an optimal environment for growing vegetable crops in greenhouses. This paper presents the results of experimental research conducted at INMA Bucharest to determine three of the most important indicators of the health of root area of vegetable crops (water content (%), pore water conductivity (CEp) and temperature (°C), while monitoring of temperature and CO2 content inside a greenhouse covered with doubled inflated foil . The results and conclusions of this study are useful in identifying optimal parameters for water supply of vegetable crops in greenhouses permanently and of adequate quality in terms of salts and temperature and also in establishing a controlled environment for uniformity of crop conditions.

8

Authors: Hăbăşescu I., Cerempei V., Balaban N.

This paper presents the obtained results of experimental research from the squeezing juice process from sweet sorghum stems. Mathematical models have allowed to obtain optimized values of functional press with rollers parameters: in the original game from the squeezing force passage of pressing speed rollers.

8

Authors: Trulli E., Torretta V., Rada E.C., Istrate I.A., Papa E.A.

The present paper examines and evaluates the results of a survey carried out to define the criteria for restoring the surface water of the karstic stream “Gravina” (Southern-Italy). The stream runs through a watershed including several agricultural areas. The stream shows an environmental heterogeneity which is of great value to the conservation of biodiversity. The analysis supports a more general water pollution control strategy aimed at safeguarding natural water quality in the urbanized watershed with the aim, also, to reuse partially the water in agriculture. The methodology was based on the surface water sampling, quality parameter analysis and simulation by modelling. The variation and compatibility of wastewater discharge and water stream quality were verified by using a model available in literature in function of biodegradable pollutant load and dissolved oxygen. Several scenarios based on the fixed yield of treatment plants were examined.

8

Authors: Villa D., Gazzola J., Dal Fabbro I.M., Silva M.V.G.

Gears are widely employed in farm machinery transmission units. However, the severe environment imposed to the machine operation generates special problems associated to maintenance, as well as to the expected time life. Machinery which works on field are exposed to excessive dust, moisture, heat, chemicals, uneven mechanical loading and quite frequently the manufacturer recommendations are not adequate or not even available. Based on that, the proposal of new methods for strain and stress distribution analysis on gears under different working conditions is considered necessary. This research paper introduces the application of moiré methods to replace the popular strain gage technique. The proposed method is included in the photomechanical techniques and is considered of easy as well as of low cost application. The moiré family of methods is based on the projection of optical grids onto the object under analysis, generating optical fringes which displace as the object is deformed under mechanical loads. In this research work the tests were carried under different working conditions, as (1) non lubricated clean gears, (2) clean and lubricated, (3) lubricated and contaminated with soil. The comparison of these three situations indicated the influence of soil contamination as well as of the lubrication. The conclusion emphasizes the application of the proposed method to gear transmission design as well as to maintenance.

10

Authors: Ivan Gh., Vlăduţ V.N.

The working capacity of conventional cereal harvesting combines is mainly determined by the working capacity of tangential threshing system. This depends on the technical and functional characteristics of the threshing system itself and the biological characteristics of the harvested vegetal mass. Portion of material driven by one bar of threshing cylinder is laminated in to the threshing space and under the action of the friction and centrifugal forces it is produced the combing of material and the seeds separation. The paper presents the kinematic study of threshing process along threshing space and the conditions for optimization of process.

10

Authors: Lijia Xu, Yu Feng, Zhangkun Fan, Dingchun Yun

Kiwi fruit grading is a key link of fruit treatment after picking. In respect that low sorting rate and grading rate of kiwi fruits affect commodity value in China, the paper acquires the volumetric characteristic of kiwi fruit through the 3D reconstruction of its three views, and fits volumetric pixel with actual weight to get a mathematical model between the two parameters, and identifies the area characteristic of the surface defect of kiwi fruit by iterative method. Volumetric characteristic and the characteristic of the surface defect are inputted into Support Vector Machine (SVM), and then suitable kernel function and kernel parameters are selected, finally the kiwi fruit grading accuracy of 97.73% is gotten. Compared with the grading accuracy of BP network with 92.11%, it can be seen that the grading effect of SVM is better than that of BP network and its grading performance is stable. The experimental results show that the SVM grading method based on kiwi fruit volume and its surface defect is feasible and can be used for online inspection of appearance quality of kiwi fruits.

10

Authors: Wang Hongliang, Shi Weidong, Wang Chuan

Currently, the Greenhouse Effect has caused great influence on the development of industry and agriculture. Considering the research development request of new-type agricultural deep well pump, the test research was taken to increase the efficiency of well pump using hydraulic design of impeller, the modern numerical CFD technology and the orthogonal test method based on quadratic regression. The experiment was carried out with two geometric factors including outlet angle and outlet width. Then ten impellers were designed as per the orthogonal testing schemes based on quadratic regression. The full flow field of the two-stage agricultural well pump including impellers and guide vanes under the design condition was simulated by CFD, finally obtaining the rated efficiency of each scheme. The influence mechanism of outlet angle and outlet width on efficiency was investigated through the orthogonal testing method. According to the calculation results, constrained quadratic regression equation of the efficiency was put forward. The result showed that it would be instructive to increase the hydraulic efficiency of the new-type deep well centrifugal pump for agriculture engineering by using the impeller maximum - diameter approach.

14

Authors: Hossein Ahmadian, Seyed Reza Hassan-Beygi, Barat Ghobadian

In this paper, a power tiller vibration was investigated at handle position as well as seat position of a trailer pulled by the power tiller. The experiments were conducted at five levels of engine speed, four levels of transmission gear ratio during transportation, and in three directions. Then the weighted 1/3rd octave spectrum was calculated from the narrow band vibration acceleration signals. The amount of vibration damage on operator's body and allowable exposure limits were calculated based on ISO standards. The results showed that the vibration increased with increasing the engine speed for all the gear ratios and directions. The magnitude of vibration was the greatest at vertical direction in all the experiments. The vibration allowable exposure time was in the range of 2.32-5.7 years at the power tiller handle for the different engine speeds and gear ratios. The total equivalent vibration, A (8), at the trailer seat was in the range of 0.5 to 0.87 m/s2 and it exceeded the allowable limits for the reduced comfort boundary, fatigue-decreased boundary and exposure limit for 8 hours/day. So, it is necessary to reduce the vibration transmitted to the operator’s hand and body by designing and developing adequate insulating system.