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Hydrogen-induced functional degradation in martensitic NiTi shape memory alloy wires under electrical actuation
No full textAbstract
Understanding the impact of hydrogen on martensitic NiTi shape memory alloy (SMA) wires is critical for ensuring the reliability of SMA-based actuators in hydrogen-rich environments. This study reveals that hydrogen charging profoundly alters the phase transformation behavior, mechanical properties, and electrical actuation performance of NiTi SMA wires. Results show that hydrogen charging reduces latent heat while elevating both martensitic and austenitic transformation temperatures. The observed increase in transformation temperatures is attributed to hydrogen-induced internal stress, which is explained using the Clausius–Clapeyron relationship. Besides, prolonged hydrogen charging reduces elongation, tensile strength, and recovery strain while increasing the critical detwinning stress and steepening the detwinning plateau. Under electrical actuation, hydrogen charging markedly decreases both actuation strain and fatigue life. Fractographic analysis confirms progressive embrittlement, which arises from multiple degradation mechanisms, including electrochemical corrosion, brittle hydride formation, and hydrogen interactions with cyclic martensitic transformations. Additionally, hydrogen charging accelerates the power-on response but slows the power-off recovery, a behavior linked to the combined effects of increased electrical resistance and reduced thermal conductivity. These findings provide critical insights into hydrogen-induced functional degradation, offering a foundation for enhancing the durability, reliability, and safety of SMA-based actuators in hydrogen-rich applications.Abstract
Understanding the impact of hydrogen on martensitic NiTi shape memory alloy (SMA) wires is critical for ensuring the reliability of SMA-based actuators in hydrogen-rich environments. This study reveals that hydrogen charging profoundly alters the phase transformation behavior, mechanical properties, and electrical actuation performance of NiTi SMA wires. Results show that hydrogen charging reduces latent heat while elevating both martensitic and austenitic transformation temperatures. The observed increase in transformation temperatures is attributed to hydrogen-induced internal stress, which is explained using the Clausius–Clapeyron relationship. Besides, prolonged hydrogen charging reduces elongation, tensile strength, and recovery strain while increasing the critical detwinning stress and steepening the detwinning plateau. Under electrical actuation, hydrogen charging markedly decreases both actuation strain and fatigue life. Fractographic analysis confirms progressive embrittlement, which arises from multiple degradation mechanisms, including electrochemical corrosion, brittle hydride formation, and hydrogen interactions with cyclic martensitic transformations. Additionally, hydrogen charging accelerates the power-on response but slows the power-off recovery, a behavior linked to the combined effects of increased electrical resistance and reduced thermal conductivity. These findings provide critical insights into hydrogen-induced functional degradation, offering a foundation for enhancing the durability, reliability, and safety of SMA-based actuators in hydrogen-rich applications
Technologies of Behaviour Change
No full textAbstract
Ways in which psychological principles become embodied in particular information technologies are often of ethical significance and an understanding of technologies related to behavior change is needed to grasp the ethical issues at stake. This chapter provides non-technical readers with a unified conception of behavior change technologies, especially information technologies, both generic technologies and technologies specifically developed for behavior change purposes, known as behavior change support systems (e.g., e-coaching modalities). Discussion of generic technologies includes basic technologies such as instant messaging systems and enabling technologies such as wearables, smart city and smart home technologies, many different kinds of sensors, and meters. The chapter also canvasses emerging technologies such as blockchain and 5G/6G telecommunication networks. It introduces the most widely used types of behavior change technologies and provides examples that have the promise to be socially disruptive, invasive, or controversial and are particularly relevant from an ethical perspective. Illustrative examples of behavior change strategies and the technologies that embody them are provided. Finally, the chapter offers explanations of the mechanisms by which designers implement behavior change.Abstract
Ways in which psychological principles become embodied in particular information technologies are often of ethical significance and an understanding of technologies related to behavior change is needed to grasp the ethical issues at stake. This chapter provides non-technical readers with a unified conception of behavior change technologies, especially information technologies, both generic technologies and technologies specifically developed for behavior change purposes, known as behavior change support systems (e.g., e-coaching modalities). Discussion of generic technologies includes basic technologies such as instant messaging systems and enabling technologies such as wearables, smart city and smart home technologies, many different kinds of sensors, and meters. The chapter also canvasses emerging technologies such as blockchain and 5G/6G telecommunication networks. It introduces the most widely used types of behavior change technologies and provides examples that have the promise to be socially disruptive, invasive, or controversial and are particularly relevant from an ethical perspective. Illustrative examples of behavior change strategies and the technologies that embody them are provided. Finally, the chapter offers explanations of the mechanisms by which designers implement behavior change
Mehrsprachige und interkulturelle Kommunikation in Tandemkursen Deutsch–Finnisch
No full textAbstract
This paper shows how participants in a Tandem programme in German and
Finnish use their multilingual repertoire as a resource when discussing cultural topics.
Tandem is a language learning format that is particularly suitable for intercultural
learning. The participants act as experts in their everyday culture, bring their cultural
perspectives to the conversation and mediate between the perspectives.
The data for this study consist of eleven recorded conversations between four tandem
pairs. The study focusses on these sequences in which cultural topics are negotiated and where a change of language occurs. The analysis shows that multilingual practices are used in a variety of ways in the conversations. Code-switching is particularly relevant at the thematic level when dealing with culture-bound expressions. However, it is also used together with translation to fill lexical gaps and negotiate roles. The participants position themselves as multilingual and multicultural individuals who can participate in and contribute to different linguistic and cultural communities. In this respect, an expansion of the intercultural perspective to multiculturalism or transculturality can be observed.Abstract
This paper shows how participants in a Tandem programme in German and
Finnish use their multilingual repertoire as a resource when discussing cultural topics.
Tandem is a language learning format that is particularly suitable for intercultural
learning. The participants act as experts in their everyday culture, bring their cultural
perspectives to the conversation and mediate between the perspectives.
The data for this study consist of eleven recorded conversations between four tandem
pairs. The study focusses on these sequences in which cultural topics are negotiated and where a change of language occurs. The analysis shows that multilingual practices are used in a variety of ways in the conversations. Code-switching is particularly relevant at the thematic level when dealing with culture-bound expressions. However, it is also used together with translation to fill lexical gaps and negotiate roles. The participants position themselves as multilingual and multicultural individuals who can participate in and contribute to different linguistic and cultural communities. In this respect, an expansion of the intercultural perspective to multiculturalism or transculturality can be observed
A tmpfs-Based Middleware for Robotics Applications
No full textAbstract
A novel inter-process communication solution based on using a temporary file system is presented. The fast read and write capabilities of random access memory and file system features are leveraged to implement a simple communication protocol between processes running on the same machine. Shareable data is saved in the tmpfs with descriptive names using the well-defined Concise Binary Object Representation (CBOR) format, making it easy to discover and decode available information. Atomic writes can be ensured using Portable Operating System Interface (POSIX) compliant rename. Using operating system features makes the system easy to implement. Example hardware and use-cases are presented, demonstrating the system’s viability. The presented use-cases show that the system can be used for interfacing sensors to be used in data collection system. Future work will include improving performance and expanding use to a robotics middleware.Abstract
A novel inter-process communication solution based on using a temporary file system is presented. The fast read and write capabilities of random access memory and file system features are leveraged to implement a simple communication protocol between processes running on the same machine. Shareable data is saved in the tmpfs with descriptive names using the well-defined Concise Binary Object Representation (CBOR) format, making it easy to discover and decode available information. Atomic writes can be ensured using Portable Operating System Interface (POSIX) compliant rename. Using operating system features makes the system easy to implement. Example hardware and use-cases are presented, demonstrating the system’s viability. The presented use-cases show that the system can be used for interfacing sensors to be used in data collection system. Future work will include improving performance and expanding use to a robotics middleware
Investigating Persuasive Software Features for Addiction Recovery
No full textAbstract
This research investigates how and to what extent Persuasive Systems Design (PSD) in Behavior Change Support Systems (BCSS) influences recovery from digital and alcohol addiction. Although digital health interventions have shown promising results in behavioral change, there is still a gap in understanding how specific persuasive software features affect addiction treatment outcomes. Therefore, this research aims to expand our understanding of effective design elements and software features for addiction recovery. Interactions of persuasive software features with well-being, self-efficacy, addiction behavior change and user engagement outputs will be assessed in three stages. Stage 1 will lay the foundation of the application design, then in Stage 2 the application will be designed and developed, and a pilot study will be conducted. Following Stage 1 and Stage 2, two experimental research are planned to test the developed BCSS's effectiveness in Stage 3. The findings of the research will provide clear views on how a BCSS can be better designed and applied to real-world settings specifically for addictions.Abstract
This research investigates how and to what extent Persuasive Systems Design (PSD) in Behavior Change Support Systems (BCSS) influences recovery from digital and alcohol addiction. Although digital health interventions have shown promising results in behavioral change, there is still a gap in understanding how specific persuasive software features affect addiction treatment outcomes. Therefore, this research aims to expand our understanding of effective design elements and software features for addiction recovery. Interactions of persuasive software features with well-being, self-efficacy, addiction behavior change and user engagement outputs will be assessed in three stages. Stage 1 will lay the foundation of the application design, then in Stage 2 the application will be designed and developed, and a pilot study will be conducted. Following Stage 1 and Stage 2, two experimental research are planned to test the developed BCSS's effectiveness in Stage 3. The findings of the research will provide clear views on how a BCSS can be better designed and applied to real-world settings specifically for addictions
From Apps to Virtual Reality: The Transferability of Compliance Drivers from Non-Virtual Reality to Virtual Reality Persuasive Systems
No full textAbstract
Owing to the unique dynamics of user interaction in virtual reality (VR), this study investigated how the determinants of compliance in conventional persuasive systems similarly affect compliance in VR. Compliance was measured subjectively and objectively in a persuasive VR environment. Partial least squares structural equation modeling was used to analyze data from 231 users of the environment. The results showed that credibility support strongly predicted perceived competence, while social support had only a negligible effect. Both primary task support and dialogue support significantly influenced perceived effectiveness, albeit with weak effect sizes. Perceived effectiveness exerted a stronger effect on perceived enjoyment than perceived competence, and perceived enjoyment strongly predicted perceived persuasiveness, which in turn significantly influenced perceived compliance. However, perceived compliance did not align with actual compliance. This highlights an intention–behavior gap. Overall, the findings confirm the transferability of compliance drivers from conventional persuasive systems to VR.Abstract
Owing to the unique dynamics of user interaction in virtual reality (VR), this study investigated how the determinants of compliance in conventional persuasive systems similarly affect compliance in VR. Compliance was measured subjectively and objectively in a persuasive VR environment. Partial least squares structural equation modeling was used to analyze data from 231 users of the environment. The results showed that credibility support strongly predicted perceived competence, while social support had only a negligible effect. Both primary task support and dialogue support significantly influenced perceived effectiveness, albeit with weak effect sizes. Perceived effectiveness exerted a stronger effect on perceived enjoyment than perceived competence, and perceived enjoyment strongly predicted perceived persuasiveness, which in turn significantly influenced perceived compliance. However, perceived compliance did not align with actual compliance. This highlights an intention–behavior gap. Overall, the findings confirm the transferability of compliance drivers from conventional persuasive systems to VR
A FRET-Based High-Throughput Screening Assay for the Discovery of Mycobacterium tuberculosis DNA ADP-Ribosylglycohydrolase DarG Inhibitors
No full textAbstract
DarTG2 is a conserved toxin-antitoxin ADP-ribosylation system that regulates bacterial survival and the antiphage response found in many pathogenic bacteria, including Mycobacterium tuberculosis. While DNA ADP-ribosyltransferase (DarT2) toxin mono-ADP-ribosylates a single-stranded DNA sequence motif and potentially induces bacterial dormancy, DNA ADP-ribosylglycohydrolase (DarG) antitoxin, containing a highly conserved macrodomain, reverses the modification and restores bacterial growth. Therefore, developing DarG-selective inhibitors may represent a promising strategy to combat tuberculosis. However, no small-molecule inhibitors targeting DarG have been identified. Here, we developed and optimized a simple and robust fluorescence resonance energy transfer (FRET)-based binding assay to identify small-molecule inhibitors targeting the DarG macrodomain. The assay utilized fluorescent fusion proteins to detect the interaction between the DarG macrodomain and an ADP-ribosylated peptide. Screening the target-focused phenotypic library using this method led to the identification of pranlukast, which selectively inhibited the DNA ADP-ribosylhydrolase activity of M. tuberculosis DarG and its bacterial orthologues, including Thermus aquaticus DarG and SCO6735 in Streptomyces coelicolor. Notably, pranlukast did not inhibit human macrodomains, indicating strong selectivity for bacterial targets. Since pranlukast has previously been reported to reduce M. tuberculosis burden, further investigation into its action mechanism in this context would be valuable.Abstract
DarTG2 is a conserved toxin-antitoxin ADP-ribosylation system that regulates bacterial survival and the antiphage response found in many pathogenic bacteria, including Mycobacterium tuberculosis. While DNA ADP-ribosyltransferase (DarT2) toxin mono-ADP-ribosylates a single-stranded DNA sequence motif and potentially induces bacterial dormancy, DNA ADP-ribosylglycohydrolase (DarG) antitoxin, containing a highly conserved macrodomain, reverses the modification and restores bacterial growth. Therefore, developing DarG-selective inhibitors may represent a promising strategy to combat tuberculosis. However, no small-molecule inhibitors targeting DarG have been identified. Here, we developed and optimized a simple and robust fluorescence resonance energy transfer (FRET)-based binding assay to identify small-molecule inhibitors targeting the DarG macrodomain. The assay utilized fluorescent fusion proteins to detect the interaction between the DarG macrodomain and an ADP-ribosylated peptide. Screening the target-focused phenotypic library using this method led to the identification of pranlukast, which selectively inhibited the DNA ADP-ribosylhydrolase activity of M. tuberculosis DarG and its bacterial orthologues, including Thermus aquaticus DarG and SCO6735 in Streptomyces coelicolor. Notably, pranlukast did not inhibit human macrodomains, indicating strong selectivity for bacterial targets. Since pranlukast has previously been reported to reduce M. tuberculosis burden, further investigation into its action mechanism in this context would be valuable
Eight element dual-band MIMO array antenna for modern fifth generation mobile phones
No full textAbstract
In this paper, an eight-element multiple-input multiple-output (MIMO) antenna with dual-band response is designed for fifth-generation (5G) mobile devices. The proposed MIMO systems’ radiators are placed in the inner side frame of the mobile phone board, which has a size of 150 × 7 mm
, each spanning an area of 21.5 × 5.5 mm. All eight antenna elements are symmetrical to each other and are fed with a 50 feeding line. The proposed MIMO antenna covers two distinct 5G frequency bands, i.e., 3.5 and 5.3 GHz, and offers −6 dB impedance bandwidth in a frequency range of 3.4–3.65 and 4.8–5.8 GHz. It is worth mentioning that an isolation of more than 18 dB is achieved over the bands of interest without the use of a decoupling network. Similarly, the proposed MIMO antenna achieved an efficiency of more than 60% across the bands, an envelope correlation coefficient (ECC) below 0.04, antenna gain better than 5 dBi, a mean effective gain (MEG) between any two radiating elements found to be better than 3 dB, and a channel capacity (CC) above 38.5 bps/Hz, which is three times better compared to a 2 × 2 MIMO antenna system. Upon fabrication and testing of the proposed antenna, it was noted that the measured results are in good agreement with the simulated data. Furthermore, the MIMO antenna response was simulated in the presence of a human user and shows how the user phantom affects the radiation characteristics of the MIMO antenna. These performance parameters showed promising results, making the proposed design a better option to be deployed in modern-day 5G communication application scenarios, specifically cell phones.Abstract
In this paper, an eight-element multiple-input multiple-output (MIMO) antenna with dual-band response is designed for fifth-generation (5G) mobile devices. The proposed MIMO systems’ radiators are placed in the inner side frame of the mobile phone board, which has a size of 150 × 7 mm
, each spanning an area of 21.5 × 5.5 mm. All eight antenna elements are symmetrical to each other and are fed with a 50 feeding line. The proposed MIMO antenna covers two distinct 5G frequency bands, i.e., 3.5 and 5.3 GHz, and offers −6 dB impedance bandwidth in a frequency range of 3.4–3.65 and 4.8–5.8 GHz. It is worth mentioning that an isolation of more than 18 dB is achieved over the bands of interest without the use of a decoupling network. Similarly, the proposed MIMO antenna achieved an efficiency of more than 60% across the bands, an envelope correlation coefficient (ECC) below 0.04, antenna gain better than 5 dBi, a mean effective gain (MEG) between any two radiating elements found to be better than 3 dB, and a channel capacity (CC) above 38.5 bps/Hz, which is three times better compared to a 2 × 2 MIMO antenna system. Upon fabrication and testing of the proposed antenna, it was noted that the measured results are in good agreement with the simulated data. Furthermore, the MIMO antenna response was simulated in the presence of a human user and shows how the user phantom affects the radiation characteristics of the MIMO antenna. These performance parameters showed promising results, making the proposed design a better option to be deployed in modern-day 5G communication application scenarios, specifically cell phones
Using Social Media to Examine Ambassadorship in Tourism
No full textAbstract
This chapter aims to examine ambassadorship on social media in the context of polar tourism. In recent years, social media has become a pervasive feature of contemporary tourism. People have been increasingly using photo applications like Instagram to share their experiences with friends, families, and sometimes thousands of unknown followers. In parallel, it has been argued that a positive impact of polar tourism is its educational value. Indeed, after visiting threatened destinations like the Arctic or Antarctica, visitors should turn into ambassadors for the protection of the visited regions and engage in pro-environmental behaviors. Given the increased use of social media in tourism, it is therefore expected that people coming back from polar destinations will share ambassadorship and pro-environmental posts online. Using netnography, this study investigates if visitors of Arctic and Antarctic destinations share pro-environmental messages on social media and if they act as ambassadors.Abstract
This chapter aims to examine ambassadorship on social media in the context of polar tourism. In recent years, social media has become a pervasive feature of contemporary tourism. People have been increasingly using photo applications like Instagram to share their experiences with friends, families, and sometimes thousands of unknown followers. In parallel, it has been argued that a positive impact of polar tourism is its educational value. Indeed, after visiting threatened destinations like the Arctic or Antarctica, visitors should turn into ambassadors for the protection of the visited regions and engage in pro-environmental behaviors. Given the increased use of social media in tourism, it is therefore expected that people coming back from polar destinations will share ambassadorship and pro-environmental posts online. Using netnography, this study investigates if visitors of Arctic and Antarctic destinations share pro-environmental messages on social media and if they act as ambassadors