A two-stage power conditioning circuit consisting of an AC DC converter followed by a DC DC converter is proposed for a vibration-based energy harvesting system. The power conditioning circuit intends to maximize the amount of power extracted from a piezoelectric energy harvester by matching the source impedance with the circuit by adaptively adjusting the duty cycle. An equivalent electrical c...

This paper presents a new energy-harvesting system with two identical piezoelectric energy harvesters in a tandem configuration. Each harvester consists of a piezoelectric beam and a circular cylinder. Experiments are performed to investigate the energy-harvesting performances of this system in water. It can be found that their energy-harvesting performances are all different from that of the s...

In this paper, a 9 degree of freedom seaweed harvester dynamical model is presented. The model presented describes the coupled dynamics of a vessel and a harvesting device, lifted by a winch, subject to sea waves disturbances. In order to find an appropriate harvesting path, which minimizes the harvester motions, the model response is simulated for different encounter angles. This 9 DOF seaweed...

The object of this study was evaluation of a walking tractor drawn peanut harvester at different conditions of soil moisture content and forward speed and comparing it with manual harvesting. The evaluation factors for peanut harvester were two levels of soil moisture content and three levels of forward speed. The results revealed that the effect of soil moisture content was only significant on...

A fundamental challenge faced by all organisms is the risk of infection by pathogens that can significantly reduce their fitness. The evolutionary dynamic between hosts and pathogens is expected to be a coevolutionary cycle, as pathogens evolve by increasing their level of virulence and hosts respond by increasing their level of resistance. The factors that influence the dynamics of adaptation ...

The process of reproductive caste determination in eusocial insect colonies is generally understood to be mediated by environmental, rather than genetic factors. We present data demonstrating unexpected genetic differences between reproductive castes in a variant of the rough harvester ant, Pogonomyrmex rugosus var. fuscatus. Across multiple loci, queens were consistently more homozygous than e...

rice is a main food for iranian people and has an important role in providing food security. regarding the population growth, increase of rice production and reduction of losses have special importance in prevention of rice import. rice losses in the harvest stage are the highest through the whole production period of this crop and hence the reduction of these losses is necessary. provision of ...