The Viking HRTF dataset v2

The Viking HRTF dataset v2 is a collection of head-related transfer functions (HRTFs) measured at the University of Iceland. It includes full-sphere HRTFs measured on a dense spatial grid (1513 positions) with a KEMAR mannequin with different pairs of artificial pinnae attached. The artificial pinnae were previously obtained through a custom molding procedure from different lifelike human heads (courtesy of Ernst Backman, Saga Museum Reykjavík)

Bioethanol production via herbaceous and agricultural biomass gasification integrated with syngas fermentation

In this paper, a simulation model based on the non-stoichiometric equilibrium method via ASPEN Plus was established to analyze the gasification performance of 20 herbaceous and agricultural biomasses (H&ABs) linked with syngas fermentation and product purification units for ethanol production. The established simulation model does not consider the gasification system as a black box; it focuses the important processes in gasification such as drying, pyrolysis, gasification, and connection with bioethanol production plants. The results for the 20 H&AB options suggest that the specific mass flow rate of bioethanol from 1 kg of biomass input to the unit is in the range of 99–250 g/kg, and between them, the system fed by hazelnut shell biomass remarkably outranked other alternatives by 241 g/kg production due to the high beneficial results gained from the performance analysis. Additionally, a sensitivity analysis was performed by changing operating conditions such as gasification temperature and air-to-fuel ratio. The modeling results are given and discussed. The established model could be a useful approach to evaluate the impacts of a huge numbers of biomasses and operating parameters on bioethanol output

Taxonomy of Means and Ends in Aquaculture Production—Part 2: The Technical Solutions of Controlling Solids, Dissolved Gasses and pH

In engineering design, knowing the relationship between the means (technique) and the end (desired function or outcome) is essential. The means in Aquaculture are technical solutions like airlifts that are used to achive desired functionality (an end) like controlling dissolved gasses. In previous work, the authors identified possible functions by viewing aquaculture production systems as transformation processes in which inputs are transformed by treatment techniques (means) and produce outputs (ends). The current work creates an overview of technical solutions of treatment functions for both design and research purposes. A comprehensive literature review of all areas of technical solutions is identified and categorized into a visual taxonomy of the treatment functions for controlling solids, controlling dissolved gasses and controlling pH alkalinity and hardness. This article is the second in a sequence of four and partly presents the treatments functions in the taxonomy. The other articles in this series present complementary aspects of this research: Part 1, A transformational view on aquaculture and functions divided into input, treatment and output functions; Part 2, The current taxonomy paper; Part 3, The second part of the taxonomy; and Part 4, Mapping of the means (techniques) for multiple treatment functionsPeer Reviewe

An Assessment of the Sustainability of Lignocellulosic Bioethanol Production from Wastes in Iceland

Publisher's version (útgefin grein).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.Peer Reviewe

Taxonomy of Means and Ends in Aquaculture Production—Part 4: The Mapping of Technical Solutions onto Multiple Treatment Functions

Designing aquaculture production units will require decisions on which treatment to include, e.g., the intensification of the system, and then a decision on a technical solution for each treatment function selected to implement. To complicate matters, each technical solution is not unique to each treatment function, but has a multiple effect on the system. This interaction of a technical solution to multiple treatment functions will play a part in the decision making process. Previous work by the authors has made a taxonomy of all technical solutions for the treatment function, and in this article, how technical solutions affect treatment functions is mapped. The article views the aquaculture production system as a transformation process with three sets of functions, input, treatment and output. Based on a comprehensive literature review where all technical solutions were found and categorized into a taxonomy, their effect on treatment function was mapped using a quality function deployment (QFD). The result is a matrix that gives an evaluation on the interaction. This work is a step towards an aquaculture engineering design methodology.Peer Reviewe

Taxonomy of Means and Ends in Aquaculture Production—Part 3: The Technical Solutions of Controlling N Compounds, Organic Matter, P Compounds, Metals, Temperature and Preventing Disease

This is the third part of the taxonomy of technical solutions and treatment functions in aquaculture. This article builds on the premiss that the aquaculture production system can be viewed as a transformation process with three sets of functions, input, treatment and output. This work creates an overview of all of the technical solutions of treatment functions for the purpose of both design and further research. This is done with a comprehensive literature review where all technical solutions are identified and then categorized into a taxonomy. The result is a visual taxonomy of the treatment functions controlling N compounds, organic matter, P compounds, metals, temperature and preventing disease. A total taxonomy is finally presented where the results from Part 2 and Part 3 (this part) have been combined.Peer Reviewe

Evaluation of an Audio-haptic Sensory Substitution Device for Enhancing Spatial Awareness for the Visually Impaired

SIGNIFICANCE: Visually impaired participants were surprisingly fast in learning a new sensory substitution device, which allows them to detect obstacles within a 3.5-m radius and to find the optimal path in between. Within a few hours of training, participants successfully performed complex navigation as well as with the white cane. PURPOSE: Globally, millions of people live with vision impairment, yet effective assistive devices to increase their independence remain scarce. A promising method is the use of sensory substitution devices, which are human-machine interfaces transforming visual into auditory or tactile information. The Sound of Vision (SoV) system continuously encodes visual elements of the environment into audio-haptic signals. Here, we evaluated the SoV system in complex navigation tasks, to compare performance with the SoV system with the white cane, quantify training effects, and collect user feedback. METHODS: Six visually impaired participants received eight hours of training with the SoV system, completed a usability questionnaire, and repeatedly performed assessments, for which they navigated through standardized scenes. In each assessment, participants had to avoid collisions with obstacles, using the SoV system, the white cane, or both assistive devices. RESULTS: The results show rapid and substantial learning with the SoV system, with less collisions and higher obstacle awareness. After four hours of training, visually impaired people were able to successfully avoid collisions in a difficult navigation task as well as when using the cane, although they still needed more time. Overall, participants rated the SoV system's usability favorably. CONCLUSIONS: Contrary to the cane, the SoV system enables users to detect the best free space between objects within a 3.5-m (up to 10-m) radius and, importantly, elevated and dynamic obstacles. All in all, we consider that visually impaired people can learn to adapt to the haptic-auditory representation and achieve expertise in usage through well-defined training within acceptable time

Heat pumps in subarctic areas: current status and benefits of use in Iceland

Heat pumps use the temperature difference between inside and outside areas to modify a refrigerant, either for heating or cooling. Doing so can lower the need for external heating energy for a household to some extent. The eventual impact depends on various factors, such as the external source for heating or cooling and the temperature difference. The use of heat pumps, and eventual benefits has not been studied in the context of subarctic areas, such as in Iceland. In Iceland, only remote areas do not have access to district heating from geothermal energy where households may, therefore, benefit from using heat pumps. It is the intent of this study to explore the observed benefits of using heat pumps in Iceland, both financially and energetically. This study further elaborates on incentives provided by the Icelandic government. Real data were gathered from the Icelandic energy authority for the analysis. It was found for the study database of 128 households that the annual electricity use was reduced from 37.8 to 26.7 kWh (an average 29.3% reduction) after installation of heat pumps. Large pumps (9.0–14.4 kW) and small pumps (5.0–9.0 kW) saved an average of 31.4 and 26.0% (95% confidence intervals), respectively. On average, households used approximately 26 MWh after installing a heat pump. When installing a small pump (5–9 kW), the mean annual saving (and 95% confidence intervals) was 10.6 ( ±± 2.7) MWh (approximately 26%). However, when installing a larger pump, mean annual savings were 11.3 ( ±± 1.6) MWh (Approximately 31%).Peer Reviewe

A Step towards the Hydrogen Economy—A Life Cycle Cost Analysis of A Hydrogen Refueling Station

This study was aimed to define a methodology based on existing literature and evaluate the levelized cost of hydrogen (LCOH) for a decentralized hydrogen refueling station (HRS) in Halle, Belgium. The results are based on a comprehensive data collection, along with real cost information. The main results indicated that a LCOH of 10.3 €/kg at the HRS can be reached over a lifetime of 20 years, if an average electricity cost of 0.04 €/kWh could be achieved and if the operating hours are maximized. Furthermore, if the initial capital costs can be reduced by 80%, in the case of direct subsidy, the LCOH could even fall to 6.7 €/kg. Keywords: hydrogen; hydrogen refueling station; levelThis study was carried out as a part of the Don Quichote (DQ) project which is co-funded by the 7th Framework Programme (FP7) under the initiative of the Fuel Cell and Hydrogen Joint Undertaking (FCH JU) under grant agreement number 303411. The author would like to use the opportunity to thank the project partners for their assistance and for letting this paper become a reality. The project partners are: Hydrogenics, Colruyt, Thinkstep, TUV, Icelandic New Energy, FAST and Waterstofnet. Special thanks to Denis Thomas at Hydrogenics for the input he provided.Peer Reviewe