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Push Button Agriculture: Summary and Futur Couorce
Published in K. R. Krishna, Push Button Agriculture, 2017
Reports from European Community nations suggest that projects to develop sophisticated robots capable of fruit picking and sorting are being developed. However, considering economic aspects, some of the research groups are first concentrating on robots to harvest high value fruit crops (Hicks, 2012). In North Americas too start-ups for harvesting robots are traceable. They are mostly concentrating on automation of maintenance and harvesting of greenhouse crops. It is believed that each such harvester could cost 25–50,000 US$. In Japan, strawberry pickers fitted with 3D vision that can carefully pick over 60% of ripe fruits in one go in the field are being developed. It turns out highly economical because such a fruit picker uses, on an average only 9 sec fruit−1 to detach and store it in a basket. These are not cumbersome robots! The general opinion is that research on Agricultural Robots is now heading from predominantly academic pursuit to private industries and commercial enterprise zone. We can guess its rapid spread in commercial farms sooner than ever before.
A framework for defining weights of decision makers in group decision-making, using consistency between different multicriteria weighting methods
Published in International Journal of Forest Engineering, 2023
Boško Blagojević, Eva-Maria Nordström, Ola Lindroos
Harvesting and moving the harvested trees to roadside for transportation are significant forestry operations, in the sense that large amounts of resources are required, large monetary values are created, and ecological and social harm may be caused by these activities (Blagojevic et al. 2019). In the Nordic countries, for example, these operations are usually performed by cut-to-length (CTL) machines. The harvester fells and processes trees into logs of various assortments (such as various kinds of saw-logs and pulp-logs). The harvester then moves the logs to the side so that it can advance (and harvest more trees) without damaging them. This results in a “machine-trail network” of paths (or “strip roads”) cleared of trees and logs. A forwarder then travels down the machine trails collecting logs and transporting them to roadside landings. The activities of this heavy machinery on wet and soft ground may cause soil compaction, which can lead to considerable long-term impact in biological activity (Heralt 2002; Horn et al. 2007) and if soil is moved and ruts are created, surface water run-off may result in leakage of sediments and pollutants such as mercury into streams (Porvari et al. 2003; Eliasson 2005). There are also economic reasons for avoiding soil damage. Driving on wet and soft ground reduces speed and/or increases fuel consumption, and a machine that becomes stuck in mud results both in severe time losses and possible machine damage (Hosseini et al. 2018).
Power performance enhancement of vortex-induced vibration wind turbines using a semi-active control approach
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Magdy Roman, Rowida Sobh, Momtaz Sedrak, Mohamed Ali
Structures in steady uniform flow may periodically shed vortices downstream which results in a fluctuating pressure field. The vortex shedding in the structure wake and the structure vibration are coupled and produce a particular flow-structure interaction; Vortex Induced Vibrations (VIV) (Feng 1968). The significance of the VIV in energy harvesting has led to a large number of research studies, especially for micro or miniature-size harvesters (Wen et al. 2021). Most of the investigations have considered VIV harvesters of the type VIVACE (vortex-induced vibration aquatic clean energy) after it was originally presented in (Bernitsas et al. 2008). The original design was quite simple; it consists of a flexibly mounted horizontal cylinder free to move normal to the freestream and attached to a linear electromagnetic alternator. This device and similar designs such as (Akaydin, Elvin, and Andreopoulos 2012) and (Mehmood et al. 2013) are, however, difficult to be upscaled economically due to their complex supporting structure. On the other hand, a vertical version of the harvester, namely VIV-BWT (vortex-induced vibration bladeless wind turbine) has the scheme that eliminates the need of complex supporting structure (Vortex Bladeless Company 2021). It consists of a cylindrical body (mast) that is vertically supported at the end of a flexible cantilever. The induced mechanical power is often converted to electric one using an electromagnetic or piezoelectric PTO. The simple structure, absence of moving parts (bearing and transmission gears), and the reduced maintenance requirements are the main features of that kind of harvesters.