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Editors and Sections Genetics and Breeding English EditorYanka Ivanova (Bulgaria) 2016 ISSN 1313 -8820 Volume 8, Number 3 September 2016Grain combines productivity according to various unloading methods -in the field and at the edge of the field Introduction leave the processed strip, move to the edge of the field and unload into vehicles (tractor vehicles or road vehicles) located outside it (Delchev et al., 2016). The reasons for this are as follows: Harvesting crops is the final stage of all activities related to their -when harvesting rice -it is practically impossible for a vehicle cultivation and is characterized by seasonality, high energy to enter into the rice "cells" (Delchev and Trendafilov, 2015); consumption, yield losses and multi-variability (Ishpekov, 2013). The -when harvesting sunflower -the sunflower stubbles harvest of cereals is one of the main activities in agriculture and it intensively destroy the vehicle tyres; should be done within a shorter period -maximum 10 -12 days, in -waterlogged soil, presence of a deep drainage ditch between order to avoid high losses of grain spillage and to reduce the risk of the road and the field or undersized area; crop damage due to environmental conditions (Nikolov et al., 1974).-use of road vehicles that are not suitable for movement onto Cereals account for the largest percentage of arable land in the stubbles. country. The process of their harvesting is fully mechanized and is It should be noted that the latter reason is becoming more characterized by simultaneous operation of harvesters, vehicles and relevant with the construction of highways in the country and the other machines that ensure this process. Of great importance is the separation of arable land in the farms, which determines the use of overall logistics of the process, which is associated both with the road vehicles with large capacity and high transport speed. proper organization and selection of a variety of ways and means to Unloading the grain tanks and moving the combines to the perform the processes. The improper method of harvesting, transport vehicles outside the field in most cases is necessary and delaying the harvesting campaign or poor organization can result in appropriate, but it is associated with additional operations, which substantial material losses (Mandradzhiev, 2006; Li et al., 2013; extend the total unloading time. This, in turn, results in a decrease in Delchev and Trendafilov, 2013; Petrovna, 2014). Important for both productivity (hourly, daily, seasonal) and in extending the harvest the organization and the combine productivity is the method of term. It is known that the combine productivity depends both on the unloading the grain tanks.technical parameters of the machine, and on the logistics factors. There are two main ways of unloading grain tanks: unloading on Such a factor is the place of unloading the full grain tanks. the go and unloading at a standstill. In terms of the organization of The objective of this article is to investigate how the unload...

Editors and Sections Genetics and Breeding ntro tionThe systems for emptying harvester grain hoppers consist of several consecutively operating augers located at a different angle ithin the hopper space igure 1 . By means of cover plates 1, located above the horizontal auger 2 the grain intake is controlled to prevent any blockage of the system. The e tent of the cover plates opening is controlled according to the type of grain, volumetric eight and its moisture level. hen the cover plates are half closed, the blockage of the system is practically impossible, but its flo rate decreases. These systems are ith a simple, easy to actuate and do not re uire special maintenance Cole, 2002 . The re uirement is to have high flo rate in order to empty the hopper for a short period of time and thus provide greater hourly and daily performance, especially hen unloading hoppers at a standstill Delchev and Trendafilov, 2002 . Usually, designers match the auger flo rate to the hopper volume, so that at 1 grain moisture the emptying to be done for 1. 2 min Isaacson, 197 .The flo rate of emptying systems, the re uired capacity of actuation and the percentage of damaged grain depend on a number of factors geometric parameters of augers, slope angle of grain transportation, type of grain, moisture, etc. It has been established that the auger slope angle has a significant effect on its flo rate, but almost no effect on grain damaging Hall, 1974 . In addition, by increasing the slope angle the re uired capacity for actuating the auger also increases and reaches its ma imum at an angle bet een 4 and 0 , and then it drops do n since the flo rate decreases. ith a vertical auger at an angle of 90 , the 2 1 e mail krasimir.trendafilov trakia uni.bg 1.: 1 -2 -3 -4 -292 capacity required for actuating is the same as in horizontal position but the flow rate is considerably lower (Midwest Plan Service, 1988). It has been found that dry grain damages (with low moisture) are minimum when using the maximum flow rate of the auger (Sands and Hall, 1971). The main characteristic of the systems for emptying harvester grain hoppers is their designed flow rate, which is given as а flow rate of the unloading auger in l/s. In fact, this flow rate is maximum possible and is reached at a nominal angle speed of the engine. This is the angle speed that drives all harvester mechanisms and systems at harvest. When unloading the grain hopper at a standstill and well-adjusted cover plates the designed flow rate of the system is practically used.It has been established that in Bulgaria the grain hopper unloading in 90% of the farms is done at a standstill (Delchev et al., 2016). In this case the operators, usually do not use the engine nominal engine revolutions, but lower ones. In that way, the designed flow rate of the emptying system is not reached, the unloading time increases and the grain harvester performance decreases. The designed flow rate cannot be reached either in the cases when cover plates 1 (Figure 1) are half-closed and not adjusted for the ...

Extrusion of wheat semolina and milled cocoa shells using a single screw extruder Brabender 20DN was carried out. Full factorial experiment 23 was used to investigate the effect of the quantity of cocoa shells, moisture of the material and temperature of the matrix on the density and expansion index of extrudates. Feed screw speed and screw speed were fixed at 30 and 200 rpm, respectively. Compression ratio of the screw was 4:1. Expansion index values range between 2.0 and 3.36 and a density between 0.099 and 0.223 g/cm3. The increase in moisture content and quantity of cocoa shells leads to a decrease expansion index, while density of extrudates an increase.

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