Next-Generation Cryo-Electric Hydrogen-Powered Aviation

Hydrogen-powered airplanes have recently attracted a revitalized push in the aviation sector to combat CO2 emissions. However, to also reduce, or even eliminate, non-CO2 emissions and contrails, the combination of hydrogen with all-electric solutions is undoubtedly the best option to move toward the ambitious goal of climate-neutral aviation. Another important design choice is to store hydrogen cryogenically in its liquid form (LH2) to reduce space occupation compared to storage as compressed gas. However, the LH2 fuels cannot be utilized directly in fuel cells. It needs to be brought from liquid to a gas at about 350 K, where large amounts of heat must be added. Thus, a synergy can be made from this otherwise wasted cryogenic refrigeration power where superconducting machines (SCMs) and cold power electronics (CPE) are low-hanging fruits that could lead to radical space and weight reductions onboard the aircraft. These opportunities can be realized without having to pay the price, nor the volume occupation and mass needed for the cooling ability usually needed to achieve these extraordinary performances. In fact, this ground-breaking synergy makes cryogenic energy conversion relevant in a whole new way for aviation. The SCMs’ more than five times higher power densities than their conventional counterparts are exceptionally significant. This article introduces the recently proposed cryo-electric drivetrain initiatives and explores the opportunities of using direct hydrogen cooling as a potential heating solution to enhance the overall performance and scalability of zero-emission propulsion systems in future regional aircraft.

Next-Generation Cryo-Electric Hydrogen-Powered Aviation

Hydrogen-powered airplanes have recently attracted a revitalized push in the aviation sector to combat CO2 emissions. However, to also reduce, or even eliminate, non-CO2 emissions and contrails, the combination of hydrogen with all-electric solutions is undoubtedly the best option to move toward the ambitious goal of climate-neutral aviation. Another important design choice is to store hydrogen cryogenically in its liquid form (LH2) to reduce space occupation compared to storage as compressed gas. However, the LH2 fuels cannot be utilized directly in fuel cells. It needs to be brought from liquid to a gas at about 350 K, where large amounts of heat must be added. Thus, a synergy can be made from this otherwise wasted cryogenic refrigeration power where superconducting machines (SCMs) and cold power electronics (CPE) are low-hanging fruits that could lead to radical space and weight reductions onboard the aircraft. These opportunities can be realized without having to pay the price, nor the volume occupation and mass needed for the cooling ability usually needed to achieve these extraordinary performances. In fact, this ground-breaking synergy makes cryogenic energy conversion relevant in a whole new way for aviation. The SCMs’ more than five times higher power densities than their conventional counterparts are exceptionally significant. This article introduces the recently proposed cryo-electric drivetrain initiatives and explores the opportunities of using direct hydrogen cooling as a potential heating solution to enhance the overall performance and scalability of zero-emission propulsion systems in future regional aircraft.

Creative Territories: Exploring Territorialisation in Shared Transient Spaces

<p>The physical spaces we occupy and inhabit are continuously changing and evolving, they are becoming increasingly transient. In response, this research is interested in learning how people occupy and inhabit transient space. Many of the spaces we occupy are affected by invisible systems controlling the amount of time we spend inside a space, and how we occupy a space. Through the study of spatial territorialisation [the creation and inhabitation of territory] this research looks at developing an understanding of behaviours and acts of territorialising in space to understand how transient space is occupied. This research looks at tertiary students as an example of people who inhabit transient spaces. Through a series of different observational experiments, students’ territories are studied to understand how they may be created and inhabited. Different techniques such as space occupation, accumulation of objects, and comfort enhancements are some of the findings of the way people have inhabited space. This thesis is interested in using this understanding of space inhabitation, learned through the different acts of territorialising, to explore how the way we design spaces might be informed from this. A final design strategy is proposed that uses the master’s studio at the Victoria University, Faculty of Architecture and Design as a site. The final design proposal uses research gathered through creative territory experiments by using installation as a tool for testing individual and communal responses to territorialising. The overall design strategy is a series of responses to the current acts of territorialising and spatial occupation occurring in the studio. The design encourages the good habits occurring in the studio such as leaving the studio for a break, and disrupts the less healthy habits, such as the permanent claiming of shared territory.</p>

Creative Territories: Exploring Territorialisation in Shared Transient Spaces

<p>The physical spaces we occupy and inhabit are continuously changing and evolving, they are becoming increasingly transient. In response, this research is interested in learning how people occupy and inhabit transient space. Many of the spaces we occupy are affected by invisible systems controlling the amount of time we spend inside a space, and how we occupy a space. Through the study of spatial territorialisation [the creation and inhabitation of territory] this research looks at developing an understanding of behaviours and acts of territorialising in space to understand how transient space is occupied. This research looks at tertiary students as an example of people who inhabit transient spaces. Through a series of different observational experiments, students’ territories are studied to understand how they may be created and inhabited. Different techniques such as space occupation, accumulation of objects, and comfort enhancements are some of the findings of the way people have inhabited space. This thesis is interested in using this understanding of space inhabitation, learned through the different acts of territorialising, to explore how the way we design spaces might be informed from this. A final design strategy is proposed that uses the master’s studio at the Victoria University, Faculty of Architecture and Design as a site. The final design proposal uses research gathered through creative territory experiments by using installation as a tool for testing individual and communal responses to territorialising. The overall design strategy is a series of responses to the current acts of territorialising and spatial occupation occurring in the studio. The design encourages the good habits occurring in the studio such as leaving the studio for a break, and disrupts the less healthy habits, such as the permanent claiming of shared territory.</p>

Exploring Assembly Trajectories of Abandoned Grasslands in Response to 10 Years of Mowing in Sub-Mediterranean Context

Abandoned semi-natural grasslands are characterized by lower plant diversity as a consequence of tall grasses spreading. Mowing is a widely used restoration practice, but its effects to maintain the restored diversity over time is poorly investigated in sub-Mediterranean grasslands. Since 2010 in the central Apennines, we fenced a grassland, invaded by Brachypodium rupestre, which was mowed twice a year. Before the experiment started, we recorded species cover in 30 random sampling units (0.5 m × 0.5 m). The sampling was repeated every two years for a total of ten years. We used linear mixed-effect models to investigate the trajectory of functional diversity and community weighted mean for traits related to space occupation, resource exploitation, temporal niche exploitation, and Grime’s CSR strategies. The reduction of the weaker competitor exclusion exerted by B. rupestre affected the functional plant community. In the short term (4–6 years), this fostered space occupation strategies, decreasing convergence of clonal strategies and horizontal space occupation types. In the longer term (8–10 years), mowing filtered ruderal strategies, i.e., species with faster resource acquisition (lower leaf dry matter content, LDMC). LDMC and CSR strategies, initially convergent due to the dominance of B. rupestre, lowered convergence over time due to higher differentiation of strategies.

Visual Creativity of Protests in Romania (2016-2019)

After the pictorial turn, it is not surprising that political messages are more and more often presented in a visual form. Today, the battle between great ideas is not only fought via texts, but also through real and virtual images, or, through imagetexts. This paper tackles the image politics of the Romanian post-2016 anti-government popular resistance through some typical cases of imagetext: hashtags, symbols, video mapping, posters and some cases of visible space-occupation. These examples can present the anonymous (in some cases professional) artistic creativity, which helps the formation of social solidarity and crystallizes the message of the resistance.

A random walk model that accounts for space occupation and movements of a large herbivore

Animal movement has been identified as a key feature in understanding animal behavior, distribution and habitat use and foraging strategies among others. Large datasets of invididual locations often remain unused or used only in part due to the lack of practical models that can directly infer the desired features from raw GPS locations and the complexity of existing approaches. Some of them being disputed for their lack of biological justifications in their design. We propose a simple model of individual movement with explicit parameters, based on a two-dimensional biased and correlated random walk with three forces related to advection (correlation), attraction (bias) and immobility of the animal. These forces can be directly estimated using individual data. We demonstrate the approach by using GPS data of 5 red deer with a high frequency sampling. The results show that a simple random walk template can account for the spatial complexity of wild animals. The practical design of the model is also verified for detecting spatial feature abnormalities and for providing estimates of density and abundance of wild animals. Integrating even more additional features of animal movement, such as individuals’ interactions or environmental repellents, could help to better understand the spatial behavior of wild animals.

Origin-Destination Data: a prototype and related scenarios

The Public Transportation System and its operation management require the processing of large amount of data (like bus routes, user data and bus schedules). In particular, origin-destination data serves to indicate citizens’ travel patterns, providing insights related to the dynamic of the urban space occupation. Given this scenario, this paper presents a prototype of origin-destination data visualization, maintaining the spatial and temporal context. The novelty relies on visualization through clustering of georreferenced data, allowing the analysis of different regions of interests (neighborhood, regionals or mathematical regions using K-means algorithm). We demonstrate the prototype through several scenarios, and interviews done to local citizens.Challenges related to meaningful presentation of results are discussed under the perspective of visualization and analytics.

Interactive System Based on Leap Motion for 3D Medical Model

An interactive visualization of the patients’ 3D medical anatomical model as guide is often helpful for doctors during complex surgery. However, there are certain limitations according to the actual requirements of building sterile operating environment. Traditional human–computer interaction tools (mouse and keyboard) must be disinfected regularly and cannot be used in the process. A noncontact gesture control medical model based on Leap Motion is proposed in this study. The gesture is recognized and localized without using mouse and keyboards through a binocular camera assembled on Leap Motion. Hence, the model is directly controlled by the gesture to complete the operation of rotation, zoom, and other functions. In this study, a 3D heart model is combined with pseudo-color processing technology to enhance the observability of its 3D structure. Gesture recognition technology is then utilized to control the rendered model as rotation and zoom. Experimental results show that our system has an absolute accuracy in recognizing circle, swipe, and other actions. Thus, rotation is proposed as a new motion that can be identified steadily. Rotation plays an essential role in usability, intuition, and interactive efficiency of future system design. The system is applicable to sterile operating environments due to its stable recognition process and small space occupation.

An In-Line Coaxial-to-Waveguide Transition for Q-Band Single-Feed-Per-Beam Antenna Systems

An in-line transition between a coaxial cable and rectangular waveguide operating in Q-band (33–50 GHz) is presented. The aim of the work is to minimize the modifications in the waveguide to the strictly necessary to overcome the manufacturing issues due to the high frequencies involved. In addition, the transition is compact and it does not increase the space occupation on the transverse section, this suggests its application in horn antennas clusters arrangement. The operating principle consists of both a modal conversion and an impedance matching between the devices. The modal conversion is realized in an intermediate region, where the coaxial penetrates in the waveguide: the device geometry is designed so that the electric field in the transition is a trade-off between the TEM mode of the coaxial and the TE10 of the guide. A shaped waveguide backshort and a reactive air gap in the coaxial cable co-participate to achieve the matching. An optimized Chebyshev stepped transformer completes the transition to fulfil the impedance mismatch with the full waveguide. The design issues and technological aspects are considered. The influences of the feeding pin misalignment, the presence of groove is included in the analysis and these practical aspects are discussed and numerically validated via the scattering parameters analysis of the proposed design. The return loss is higher than 25 dB over the whole Q-band.