A. C. Hansen

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The energy requirement for biomass comminution and the resulting particle physical properties are important factors to study logistic components, select equipment, and assess the overall efficiency of feedstock supply–conversion chain. In this study, mechanical size reduction of Miscanthus (Miscant-hus giganteus), switchgrass (Panicum virgatum), willow(More)
Lignocellulosic biomass feedstock transportation bridges biomass production, transformation, and conversion into a complete bioenergy system. Transportation and associated logistics account for a major portion of the total feedstock supply cost and energy consumption, and therefore improvements in transportation can substantially improve the(More)
The low bulk density and low flowability of lignocellulosic biomass feedstock have been regarded widely as major barriers for a sustainable and efficient supply system. Densification of biomass is a viable option to increase the bulk (and inherent energy) density and flowability of feedstock, leading to improved efficiency of the supply system. The energy(More)
One of the reasons for relatively high biomass harvesting cost is challenges in adjusting the ground speed of harvesting machines with respect to the yield level within a field. A real-time biomass yield sensor that can predict the yield in front of a machine could be a useful tool to control ground speed. It was hypothesized that the force required to bend(More)
The cost of harvesting is one of the constraints in improving biofuel economics. Adjusting the ground speed of harvesting machines to maximize their throughput rate in relation to yield level is one of the ways to reduce harvesting cost. To control the ground speed of a baler, a real-time sensor that can predict the swathed-biomass yield in front of the(More)
Previous studies highlighted the need to develop efficient harvesting and size reduction equipment for miscanthus. This study investigated the effect of blade oblique angles and cutting speeds on cutting energy. Cutting blade speed, before and after severing a single miscanthus stem, was used to calculate the cutting energy. The cutting energy was(More)
The biomass-based energy sector will play an important role in our drive towards renewable energy. Switchgrass has been identified as one of the candidate-dedicated energy crops in the USA because of its various desirable traits. However, many challenges still exist in ensuring a commercially viable switchgrass crop that is sustainable and(More)
Impact cutting Harvesting Energycane Biomass Bioenergy Size reduction Energycane is a promising bioenergy crop for warm southeastern US regions and existing sugarcane machinery is being adapted for energycane cultivation. Because of energycane's comparatively higher fibre content and smaller stem diameters, the cutting blades must be optimized for(More)
" The questions here are whether the existing grain-producing infrastructure is capable of handling these huge volumes of biomass, and what potential barriers must be addressed through research to accomplish the goal as stated. The US Biomass R&D Technical Advisory Committee has envisioned a 30% replacement of the current US petroleum consumption with(More)
We report on new barriers in the theory of computations. These barriers show that the standard theory of computations and complexity theory is insufficient for many core problems in computational theory. Thus we are in need of a new extended complexity theory. The new theory settles the long standing computational spectral problem and also provides new(More)