Reza Abdi

Modeling and Analysis of Mechanization Projects of Wheat Production by GERT Networks

In crop production systems, all operations such as seed bed preparation, etc., must be accomplished on time, if yield reduction and low quality product are to be avoided. Therefore all operations in mechanized cropping projects require precise scheduling, planning and management. The basic approach in all scheduling techniques is to form a network of activities and events relationships that graphically portrays the sequential relations between the tasks in a project. Such a network would as a powerful tool available a farm manager to plan, schedule, monitor and control a project. Since GERT (Graphical Evaluation and Review Technique) networks have most of advantages associated with networks and available system analyst in exact evaluation of certain types of networks, in this research it was used and mechanized wheat production system was simulated, modeled and analyzed. Critical activities, events and path were determined. Results showed that the network model was able to answer any statistic questions concerning with the project. Network models, particularly GERT networks are increasingly powerful tool for modeling, scheduling, planning, controlling, and analyzing of agricultural mechanization projects.

Energy Consumption, Input-Output Relationship and Cost Analysis for Greenhouse Productions in Esfahan Province of Iran

The objectives of this study were to determine the energy consumption and evaluation of inputs sensitivity for greenhouse vegetable production in the Esfahan province of Iran. Data were collected from 60 farmers using a face–to–face questionnaire method. The majority of farmers in the surveyed region were growing cucumber and tomato. The results revealed that cucumber production was the most energy intensive rather than tomato production. Cucumber production consumed a total of 124.44 G J ha –1 followed by tomato with 116.76 G J ha –1 . The energy ratio (energy use efficiency) for greenhouse tomato and cucumber were estimated to be 0.92 and 0.56 respectively. This indicated an intensive use of inputs in greenhouse vegetable production not accompanied by increase in the final product. Econometric model evaluation showed the impact of human power for both tomato and cucumber production was significant at 1% levels and had the highest impact among the other inputs in greenhouse tomato and cucumber production. Economic analysis indicated that the total costs of production for one hectare of tomato

Attributional and consequential environmental assessment of using waste cooking oil- and poultry fat-based biodiesel blends in urban buses: a real-world operation condition study

Urban public transportation sector in general is heavily dependent on fossil-oriented fuels, e.g., diesel. Given the fact that a major proportion of urban pollution and the consequent threats towards public health are attributed to this sector, serious efforts at both technical and political levels have been being made to introduce less-polluting fueling regimes, e.g., partial replacement of diesel with biodiesel. In line with that, the present study was aimed at evaluating the emissions attributed to 5% blends of waste cooking oil (WCO) and poultry fat (PF) biodiesel fuels (i.e., B5-WCO and B5-PF fuel blends) when used in urban buses during idle operation mode. Moreover, the attributional and consequential environmental impacts of using these fuel blends were also investigated through a well to wheel life cycle assessment (LCA) by considering the real-world condition combustion data using ten urban buses. The findings of the ALCA revealed that the application of 1 L B5-WCO fuel blend could potentially reduce the environmental burdens in human health, ecosystem quality, and resources damage categories compared with using the B5-PF fuel blend. The situation was opposite for climate change damage category in which using 1 L B5-PF fuel blend had a lower impact on the environment. Overall, the environmental hotspots in the B5-WCO and B5-PF life cycles were identified as the combustion stage as well as the diesel production and transportation. From the consequential perspective, using 1 L B5-WCO fuel blend could potentially decrease the environmental burdens in human health, ecosystem quality, and resources damage categories. While, the situation was different for climate change damage category where using 1 L B5-PF fuel blend could have a lower impact on the environment. In conclusion, using B5-WCO fuel blend as an alternative for diesel could be an environmentally-friendly decision for the Iranian urban transportation sector at the policy level as long as the marginal suppliers of oil would be the same as the countries considered herein, i.e., Malaysia and Argentina.