Currently around 10% of all energy generated worldwide comes from biomass. Most of this 10% is biofuel energy from the fermentation of corn and sugarcane. Fermentation of corn competes with the global food supply, and fermentation of sugarcane drives deforestation. Therefore, the renewable and sustainable growth of these two bio-based energy sources may not be desirable even if it is economically feasible. Biomass gasification by contrast is significantly more flexible in terms of the bio-feedstock or waste that can be processed to either produce biofuels or to co-generate electricity and heat on demand. This superior flexibility of gasification both in terms of the feedstock type and also the energy generation or fuel production options, is what drives expanding research and implementation opportunities for biomass gasification. Research progress is accelerated by modelling work. This review is the first review in the biomass gasification modelling field to collect and analyze statistics on the growing number of gasification modelling studies and approaches used. The frequency of the various modelling choices made, and the trends this data reveals, is reported. For new researchers this review provides a succinct guide to the modelling choices that needs to made early on in a modelling study or project. A detailed methodology characterization is introduced that includes consequential modelling choices not explicitly addressed by prior reviews. To seasoned researchers this study provides the first statistical (as opposed to ad hoc or anecdotal) picture of what their fellow researchers are doing. The data to be presented reveals that even though the availability of kinetic data increased over the last two decades, the fraction of simulations that utilize kinetic modelling (as opposed to pure equilibrium calculations) decreased from roughly 50% to around 25% over the last decade.

An exciting possibility for compensating for loss of sensory function is to augment deficient senses by conveying missing information through an intact sense. Here we present an overview of techniques that have been developed for sensory substitution (SS) for the blind, through both touch and audition, with special emphasis on the importance of training for the use of such devices, while highlighting potential pitfalls in their design. One example of a pitfall is how conveying extra information about the environment risks sensory overload. Related to this, the limits of attentional capacity make it important to focus on key information and avoid redundancies. Also, differences in processing characteristics and bandwidth between sensory systems severely constrain the information that can be conveyed. Furthermore, perception is a continuous process and does not involve a snapshot of the environment. Design of sensory substitution devices therefore requires assessment of the nature of spatiotemporal continuity for the different senses. Basic psychophysical and neuroscientific research into representations of the environment and the most effective ways of conveying information should lead to better design of sensory substitution systems. Sensory substitution devices should emphasize usability, and should not interfere with other inter- or intramodal perceptual function. Devices should be task-focused since in many cases it may be impractical to convey too many aspects of the environment. Evidence for multisensory integration in the representation of the environment suggests that researchers should not limit themselves to a single modality in their design. Finally, we recommend active training on devices, especially since it allows for externalization, where proximal sensory stimulation is attributed to a distinct exterior object.

Vibrotactile displays can compensate for the loss of sensory function of people with permanent or temporary deficiencies in vision, hearing, or balance, and can augment the immersive experience in virtual environments for entertainment, or professional training. This wide range of potential applications highlights the need for research on the basic psychophysics of mechanisms underlying human vibrotactile perception. One key consideration when designing tactile displays is determining the minimal possible spacing between tactile motors (tactors), by empirically assessing the maximal throughput of the skin, or, in other words, vibrotactile spatial acuity. Notably, such estimates may vary by tactor type. We assessed vibrotactile spatial acuity in the lower thoracic region for three different tactor types, each mounted in a 4 × 4 array with center-to-center inter-tactor distances of 25 mm, 20 mm, and 10 mm. Seventeen participants performed a relative three-alternative forced-choice point localization task with successive tactor activation for both vertical and horizontal stimulus presentation. The results demonstrate that specific tactor characteristics (frequency, acceleration, contact area) significantly affect spatial acuity measurements, highlighting that the results of spatial acuity measurements may only apply to the specific tactors tested. Furthermore, our results reveal an anisotropy in vibrotactile perception, with higher spatial acuity for horizontal than for vertical stimulus presentation. The findings allow better understanding of vibrotactile spatial acuity and can be used for formulating guidelines for the design of tactile displays, such as regarding inter-tactor spacing, choice of tactor type, and direction of stimulus presentation.

This paper describes the development of a model to comprehensively assess the sustainability impacts of producing lignocellulosic bioethanol from various types of municipal organic wastes (MOWs) in Iceland: paper and paperboard, timber and wood and garden waste. The tool integrates significant economic, energy, environmental and technical aspects to analyse and rank twelve systems using the most common pretreatment technologies: dilute acid, dilute alkali, hot water and steam explosion. The results show that among the MOWs, paper and paperboard have higher positive rankings under most assessments. Steam explosion is also ranked at the top from the economic, energy and environmental perspectives, followed by the hot water method for paper and timber wastes. Finally, a potential evaluation of total wastes and bioethanol production in Iceland is carried out. The results show that the average production of lignocellulosic bioethanol in 2015 could be 12.5, 11 and 3 thousand tons from paper, timber and garden wastes, respectively, and that production could reach about 15.9, 13.7 and 3.7 thousand tons, respectively, by 2030.