Template-Type: ReDIF-Article 1.0 Author-Name: M. Pexa Author-Workplace-Name: Department for Quality and Dependability of Machines, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: K. Kubín Author-Workplace-Name: Research Institute of Agricultural Engineering, Prague, Czech Republic Title: Effect of rapeseed methyl ester on fuel consumption and engine power Abstract: This paper describes the effect of a mixture of rapeseed methyl ester and diesel oil on fuel consumption and power parameters of tractor engine. The hydraulic dynamometer was used to load the engine of Zetor Forterra 8641 tractor over rear power take-off. The measured tractor is almost new with less than 100 h worked. The measurements were realized for several ratios of diesel oil and rapeseed methyl ester (from pure diesel to pure rapeseed methyl ester). The engine was loaded by the dynamometer in several working points which were predefined by engine speed and its torque. The fuel consumption was measured by the flow meter in each of these points. The reduction of engine's power parameters and the increase of specific fuel consumption are expected due to the nature of rapeseed methyl ester such as e.g. lower calorific value. Keywords: biofuel, speed characteristic, engine map Journal: Research in Agricultural Engineering Pages: 37-45 Volume: 58 Issue: 2 Year: 2012 DOI: 10.17221/41/2011-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/41/2011-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-201202-0001.txt Handle: RePEc:caa:jnlrae:v:58:y:2012:i:2:id:41-2011-RAE Template-Type: ReDIF-Article 1.0 Author-Name: J. Souček Author-Workplace-Name: Research Institute of Agricultural Engineering, Prague, Czech Republic Author-Name: D. Blažej Author-Workplace-Name: Department of Machinery Utilization, Faculty of Engineering, Czech University of Life Science Prague, Prague, Czech Republic Title: Linseed harvests parameters depending on the state of cutting mechanism Abstract: The operating and economical parameters of agricultural products harvesting are important aspects from production costs point of view. Profitability of the crops depends on quantity and quality of end products and efficiency of growing and harvesting operations. In case of linseeds harvesting by combine harvester statistically important impact of cutting mechanisms state on energy, exploitation and economical parameters was determined. Keywords: flax, combine harvesting, energy consumption, GPS Journal: Research in Agricultural Engineering Pages: 46-49 Volume: 58 Issue: 2 Year: 2012 DOI: 10.17221/36/2011-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/36/2011-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-201202-0002.txt Handle: RePEc:caa:jnlrae:v:58:y:2012:i:2:id:36-2011-RAE Template-Type: ReDIF-Article 1.0 Author-Name: M.R. Jadidi Author-Workplace-Name: Department of Agricultural Economics, Faculty of Agriculture, University of Zabol, Zabol, Iran Author-Name: M.S. Sabuni Author-Workplace-Name: Department of Agricultural Economics, Faculty of Agriculture, University of Zabol, Zabol, Iran Author-Name: M. Homayounifar Author-Workplace-Name: Department of Economics, Faculty of Economic and Administrative Sciences, Ferdowsi University of Mashhad, Mashhad, Iran Author-Name: A. Mohammadi Author-Workplace-Name: Department of Agricultural Machinery Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran Title: Assessment of energy use pattern for tomato production in Iran: A case study from the Marand region Abstract: The aim of the contribution was to determine energy consumption of input and output used in tomato production and to optimize the energy inputs in the Marand region, Iran. The study also sought to analyse the effect of farm size on energy use and input costs based on tomatoes production and to reveal the relationship between energy inputs and yield by developing mathematical models. Questions about energy management present very interesting and actual topic in this time. The results revealed that tomato production consumed a total of 65,238.9 MJ/ha of which fertilizers were 50.98% followed by water for irrigation (20.67%). Output-input energy and energy productivity were found to be 0.59 and 0.74 kg/MJ, respectively. The results of energy optimization showed that using existing energy inputs, the yield of tomato can be increased by 45.2% in small farms, 43.5% in medium farms and 30% in large farms. The rate of direct, indirect, renewable and non-renewable energy forms were found to be 37.2, 62.8, 30.9 and 69.1% of total energy input, respectively. The main non-renewable inputs were chemical fertilizers and diesel fuel, management of plant nutrients and proper machinery selection to reduce diesel fuel use would increase rate of renewable energy. Keywords: energy productivity, diesel fuel, optimization, non-renewable energy, Iran Journal: Research in Agricultural Engineering Pages: 50-56 Volume: 58 Issue: 2 Year: 2012 DOI: 10.17221/32/2010-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/32/2010-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-201202-0003.txt Handle: RePEc:caa:jnlrae:v:58:y:2012:i:2:id:32-2010-RAE Template-Type: ReDIF-Article 1.0 Author-Name: R. Adamovský Author-Workplace-Name: Department of Mechanical Engineering, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: L. Mašek Author-Workplace-Name: Department of Mechanical Engineering, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: P. Neuberger Author-Workplace-Name: Department of Mechanical Engineering, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic Title: Analysis of rock mass borehole temperatures with vertical heat exchanger Abstract: The goal of the article is to analyze the distribution and changes of temperatures in boreholes with the rock mass/fluid tubular heat exchangers used as an energy source for the heat pump. It also aims at documenting changes of temperatures in the rock mass during stagnation and heat extraction, and to compare the temperatures in the active and referential borehole. The testing results showed that temperatures of the rock mass reached a minimal value of 1.3°C at depths of 9 m and 20 m with maximal heat extraction corresponding to minimal air temperatures. The temperatures of the rock mass increased near the end of the heating season to values which correspond to the initial values. The temperature differences of the rock mass between the reference borehole and active boreholes increased to up to 10.5 K during the heating season. However, the temperature differences at the end of the heating season between the reference and active boreholes dropped back to 0.5-1.1 K. Keywords: geothermal, heat pumps, temperature laps rate, thermal conductivity, thermal resistance, heat capacity Journal: Research in Agricultural Engineering Pages: 57-65 Volume: 58 Issue: 2 Year: 2012 DOI: 10.17221/43/2011-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/43/2011-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-201202-0004.txt Handle: RePEc:caa:jnlrae:v:58:y:2012:i:2:id:43-2011-RAE Template-Type: ReDIF-Article 1.0 Author-Name: N.A. Aviara Author-Workplace-Name: Department of Agricultural and Environmental Resources Engineering, University of Maiduguri, Maiduguri, Nigeria Author-Name: O.A. Onuh Author-Workplace-Name: Department of Agricultural and Environmental Resources Engineering, University of Maiduguri, Maiduguri, Nigeria Author-Name: S.E. Ehiabhi Author-Workplace-Name: Department of Agricultural and Environmental Resources Engineering, University of Maiduguri, Maiduguri, Nigeria Title: Influence of moisture content and loading orientation on some mechanical properties of Mucuna flagellipes nut Abstract: The effects of moisture content and loading orientation on some strength properties of Mucuna flagellipes nut namely, bioyield, yield and rupture points; bioyield, compressive and rupture strengths; and moduli of elasticity, resilience, toughness and stiffness were determined at lateral and longitudinal axial loading, using a Testometric Universal Testing Machine (UTM). In the moisture range of 3.38-10.7% (d.b.), bioyield, yield and rupture points of the nut decreased from 1,137 to 755 N, 1,157 to 790 N and 685 to 365 N, respectively, when loading was on the lateral axis, and increased from 1,090 to 1,888 N, 1,092 to 1,918 N and 420 to 1,215 N on longitudinal loading. Bioyield strength (1.83-1.41 N/mm2), compressive strength (1.85-1.44 N/mm2) and rupture strength (1.03-0.74 N/mm2), decreased with increase in moisture content under lateral loading, but increased from 4.05 to 8.17 N/mm2, 4.15 to 8.45 N/mm2 and 2.6 to 6.3 N/mm2, respectively, as the moisture content increased in the above range, under longitudinal loading. The elasticity, toughness and stiffness moduli of the nut decreased (23-16.6 N/mm2, 0.615-0.525 J and 272.8-250 N/mm, respectively) with increase in moisture content under lateral loading, and increased (34.5-66.56 N/mm2, 0.508-0.69 J and 246-369 N/mm, respectively) with moisture content on longitudinal loading. On the above loading orientations, modulus of resilience increased from 0.166 to 0.355 J, and 0.255 to 0.576 J respectively, with moisture content. The properties were higher on the longitudinal than lateral axial loading. Second order polynomial equations relating these properties to moisture content were established. Keywords: bioyield, compressive tests, modulus of elasticity, rupture, strength properties, Nigeria Journal: Research in Agricultural Engineering Pages: 66-72 Volume: 58 Issue: 2 Year: 2012 DOI: 10.17221/12/2011-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/12/2011-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-201202-0005.txt Handle: RePEc:caa:jnlrae:v:58:y:2012:i:2:id:12-2011-RAE Template-Type: ReDIF-Article 1.0 Author-Name: R. Amiri Chayjan Author-Workplace-Name: Department of Agricultural Machinery Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran Author-Name: K. Salari Author-Workplace-Name: Department of Agricultural Machinery Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran Author-Name: B. Shadidi Author-Workplace-Name: Department of Agricultural Machinery Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran Title: Modeling some drying characteristics of garlic sheets under semi fluidized and fluidized bed conditions Abstract: Thin layer drying properties of high moisture garlic sheets under semi fluidized and fluidized bed conditions with high initial moisture content (about 154.26% d.b.) were studied. Air temperatures of 50, 60, 70 and 80°C were applied to garlic samples. Among the applied models, Page model was the best to predict the thin layer drying behavior of garlic sheets. Using this model, correlation coefficient (R2) was high for all drying cases. The computed values of Deff were between 3.38 × 10-10 and 2.54 × 10-9 m2/s during the falling rate drying. Values of Deff for garlic sheets were also increased with increasing in input air temperature. Activation energy values were varied between 51.32 and 60.58 kJ/mol for 50 to 80°C, respectively. The specific energy consumption (SEC) for garlic specimens was placed in the range of 0.316 × 106 and 0.979 × 106 kJ/kg from 50 to 80°C, respectively. An increase in air temperature caused decrease in SEC value. Application of semi fluidized bed convective drying with temperature between 50 and 60°C was suitable to produce dried garlic. Keywords: energy, diffusivity, garlic, moisture ratio, Page model Journal: Research in Agricultural Engineering Pages: 73-82 Volume: 58 Issue: 2 Year: 2012 DOI: 10.17221/42/2011-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/42/2011-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-201202-0006.txt Handle: RePEc:caa:jnlrae:v:58:y:2012:i:2:id:42-2011-RAE