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1 – 10 of 364
Article
Publication date: 7 April 2023

Chiara Bedon and Christian Louter

Glass material is largely used for load-bearing components in buildings. For this reason, standardized calculation methods can be used in support of safe structural design in…

Abstract

Purpose

Glass material is largely used for load-bearing components in buildings. For this reason, standardized calculation methods can be used in support of safe structural design in common loading and boundary conditions. Differing from earlier literature efforts, the present study elaborates on the load-bearing capacity, failure time and fire endurance of ordinary glass elements under fire exposure and sustained mechanical loads, with evidence of major trends in terms of loading condition and cross-sectional layout. Traditional verification approaches for glass in cold conditions (i.e. stress peak check) and fire endurance of load-bearing members (i.e. deflection and deflection rate limits) are assessed based on parametric numerical simulations.

Design/methodology/approach

The mechanical performance of structural glass elements in fire still represents an open challenge for design and vulnerability assessment. Often, special fire-resisting glass solutions are used for limited practical applications only, and ordinary soda-lime silica glass prevails in design applications for load-bearing members. Moreover, conventional recommendations and testing protocols in use for load-bearing members composed of traditional constructional materials are not already addressed for glass members. This paper elaborates on the fire endurance and failure detection methods for structural glass beams that are subjected to standard ISO time–temperature for fire exposure and in-plane bending mechanical loads. Fire endurance assessment methods are discussed with the support of Finite Element (FE) numerical analyses.

Findings

Based on extended parametric FE analyses, multiple loading, geometrical and thermo-mechanical configurations are taken into account for the analysis of simple glass elements under in-plane bending setup and fire exposure. The comparative results show that – in most of cases – thermal effects due to fire exposure have major effects on the actual load-bearing capacity of these members. Moreover, the conventional stress peak verification approach needs specific elaborations, compared to traditional calculations carried out in cold conditions.

Originality/value

The presented numerical results confirm that the fire endurance analysis of ordinary structural glass elements is a rather complex issue, due to combination of multiple aspects and influencing parameters. Besides, FE simulations can provide useful support for a local and global analysis of major degradation and damage phenomena, and thus support the definition of simple and realistic verification procedures for fire exposed glass members.

Article
Publication date: 23 January 2024

Zachary Wahl-Alexander, Jennifer Jacobs, Christopher M. Hill and Gabrielle Bennett

The purpose of this study was to examine the impact of a sport-leadership program on minority incarcerated young adults’ health-related fitness markers.

Abstract

Purpose

The purpose of this study was to examine the impact of a sport-leadership program on minority incarcerated young adults’ health-related fitness markers.

Design/methodology/approach

This study occurred at an all-male juvenile detention center. A total of 41 participants in this study were obtained from a sample of 103 incarcerated young adults. Data collection entailed body mass index (BMI) evaluation, cardiovascular endurance tests and 1-min pushups and situps at two different time periods (before and after three months). A 2 × 2 mixed factorial analysis of variances was used to test for differences among the within subjects’ factors (time [pre × post]) and between subjects’ factors (groups [flex × control]) for the above-mentioned dependent variables.

Findings

Over the course of three consecutive months of engagement, preliminary indications demonstrated participants had a slight reduction in BMI and significant increases in cardiovascular endurance and muscle strength. Contrarily, during this same time period, non-participating young adults exhibited significant increases in BMI and decreases in cardiovascular endurance and muscle strength.

Originality/value

Integration of sport-leadership programs is generally not free but can be a low-cost alternative for combatting many issues surrounding physical activity, weight gain and recreational time for those incarcerated.

Details

International Journal of Prison Health, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2977-0254

Keywords

Book part
Publication date: 14 December 2023

Diana Tracy Cohen

This chapter focuses on a population that I call iron moms: women who negotiate work, family, and endurance sport identities. This research sheds light on how mothers with…

Abstract

This chapter focuses on a population that I call iron moms: women who negotiate work, family, and endurance sport identities. This research sheds light on how mothers with families, full-time jobs, and other responsibilities fit a high level of endurance training into their lives. Looking at endurance sport through the lens of gender and parenthood helps uncover the unique complexities that iron moms face juggling their multiple identities. Included is an assessment of how iron moms manage their status on the athletic visibility continuum as a process associated with identity construction and maintenance. Based on an analysis of in-depth interviews with 20 active iron mom competitors and textual analysis of triathlon blog postings, this work uncovers the details of how these women attempt to find satisfaction in multiple areas of their lives. This chapter suggests that navigating one's status on the athletic visibility continuum in addition to navigating the complex web of dominant social discourses surrounding motherhood play a critical role in shaping how women craft their existence as an iron mom. Findings stress the value of “me time,” the pervasiveness of “mom guilt,” and the importance of reframing dominant discourses about motherhood.

Details

Family and Sport
Type: Book
ISBN: 978-1-80262-993-4

Keywords

Article
Publication date: 26 December 2023

Ting Dai and Chang Tao

For a thermal protection system (TPS) of long endurance hypersonic flight vehicle (HFV), its thermal insulation property not only determines by the manufactured morphology but…

Abstract

Purpose

For a thermal protection system (TPS) of long endurance hypersonic flight vehicle (HFV), its thermal insulation property not only determines by the manufactured morphology but also changes along time. A thermal conductivity prediction model for aerogel considering heat treatment effect is carried out and applied to solve the heat conduction problem of a TPS. The aim of this study is to provide theoretical and numerical references for further development of aerogels applying to TPSs.

Design/methodology/approach

A thermal conductivity prediction model for aerogel is established considering treatment effect. The heat conduction problem of a TPS is derived and solved by combining the differential quadrature method and the Runge–Kutta method. The prediction results of aerogel thermal conductivities are verified by comparing with those in literature, while the calculated temperature field of TPS is verified by comparing with that by ABAQUS.

Findings

Numerical results show that when applying the current prediction model, the calculated high temperature area in the aerogel layer is narrowed due to the decrease of the thermal conductivity during heat treatment process.

Originality/value

This study will be beneficial to carry out the precise design of TPS for long endurance HFVs.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 4 August 2023

Elisa Herold, Pamela Wicker, Uta Czyrnick-Leber, Bernd Gröben and Milan Dransmann

The purpose of this study is to examine the effects of four different sport programs on various social and subjective health outcomes among prisoners.

Abstract

Purpose

The purpose of this study is to examine the effects of four different sport programs on various social and subjective health outcomes among prisoners.

Design/methodology/approach

Four different sport programs (endurance, strength, dance-like martial arts, soccer) were provided in 2020 and 2021 in a German prison. Participants completed paper-pencil surveys before and after the sport programs (n = 134 observations), including questions about potential social health (enjoyment of physical activity, interpersonal exchange, interpersonal trust, self-efficacy) and subjective health outcomes (health status, health satisfaction, well-being). Further information such as prisoner characteristics were added to the data.

Findings

Results of regression analyses show that the endurance program had a significant positive effect on interpersonal trust, while the soccer program had a negative effect. Subjective well-being increased significantly after the strength and the soccer program. The weekly sport hours before imprisonment had a positive association with enjoyment of physical activity and interpersonal exchange while being negatively related to health status and health satisfaction. Furthermore, the number of months of imprisonment before the survey, being a young offender, the prisoners’ body mass index, educational level and migration background were significantly associated with several social and subjective health outcomes.

Originality/value

This study analyzed the effects of different sport programs for prisoners on various social and subjective health outcomes, revealing differences across programs and outcomes. The findings suggest that sport can be a way to enhance prisoners’ social and subjective health, ultimately facilitating their rehabilitation process.

Details

International Journal of Prisoner Health, vol. 19 no. 4
Type: Research Article
ISSN: 1744-9200

Keywords

Article
Publication date: 13 February 2024

Yi Xia, Yonglong Li, Hongbin Zang, Yanpian Mao, Haoran Wang and Jialong Li

A switching depth controller based on a variable buoyancy system (VBS) is proposed to improve the performance of small autonomous underwater vehicles (AUVs). First, the…

Abstract

Purpose

A switching depth controller based on a variable buoyancy system (VBS) is proposed to improve the performance of small autonomous underwater vehicles (AUVs). First, the requirements of VBS for small AUVs are analyzed. Second, a modular VBS with high extensibility and easy integration is proposed based on the concepts of generality and interchangeability. Subsequently, a depth-switching controller is proposed based on the modular VBS, which combines the best features of the linear active disturbance rejection controller and the nonlinear active disturbance rejection controller.

Design/methodology/approach

The controller design and endurance of tiny AUVs are challenging because of their low environmental adaptation, limited energy resources and nonlinear dynamics. Traditional and single linear controllers cannot solve these problems efficiently. Although the VBS can improve the endurance of AUVs, the current VBS is not extensible for small AUVs in terms of the differences in individuals and operating environments.

Findings

The switching controller’s performance was examined using simulation with water flow and external disturbances, and the controller’s performance was compared in pool experiments. The results show that switching controllers have greater effectiveness, disturbance rejection capability and robustness even in the face of various disturbances.

Practical implications

A high degree of standardization and integration of VBS significantly enhances the performance of small AUVs. This will help expand the market for small AUV applications.

Originality/value

This solution improves the extensibility of the VBS, making it easier to integrate into different models of small AUVs. The device enhances the endurance and maneuverability of the small AUVs by adjusting buoyancy and center of gravity for low-power hovering and pitch angle control.

Details

Industrial Robot: the international journal of robotics research and application, vol. 51 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 25 May 2022

Fatwa Azam Maulana, Ema Amalia and Mochammad Agoes Moelyadi

High Altitude Long Endurance Unmanned Aerial Vehicle (HALE UAV) driven by a hybrid power between battery and solar panel have attracted many researchers. The HALE UAV which…

Abstract

Purpose

High Altitude Long Endurance Unmanned Aerial Vehicle (HALE UAV) driven by a hybrid power between battery and solar panel have attracted many researchers. The HALE UAV which develops at Bandung Institute of Technology has design requirements of a 63 kg MTOW with a cruise velocity of 22.1 m/s at an altitude of 60,000 ft propelled by two propellers. The main problems that arise with the propellers gained from the market are these propellers cannot operate properly at the cruise phase due to inadequate thrust and high drag value. This paper aims to design a propeller that solves those problems.

Design/methodology/approach

The Larrabee method is used to design this propeller geometry with an output in the form of a chord and twist distribution. The CFD approach method is used to improve the design resulting from the Larrabee method.

Findings

This study shows that the inputted thrust value of the propeller designed using the Larrabee method is always higher than the thrust value resulting from the CFD simulation with a difference of around 20% so a design improvement process using CFD is required.

Originality/value

The analysis of propeller implementation in various mission profiles shows that this propeller can operate fully from climbing at sea level to cruising flight at an altitude of 60,000 ft. The same procedure can be applied in other HALE UAV cases to generate a propeller design with different objectives.

Details

International Journal of Intelligent Unmanned Systems, vol. 11 no. 3
Type: Research Article
ISSN: 2049-6427

Keywords

Article
Publication date: 6 March 2024

Xiaohui Li, Dongfang Fan, Yi Deng, Yu Lei and Owen Omalley

This study aims to offer a comprehensive exploration of the potential and challenges associated with sensor fusion-based virtual reality (VR) applications in the context of…

Abstract

Purpose

This study aims to offer a comprehensive exploration of the potential and challenges associated with sensor fusion-based virtual reality (VR) applications in the context of enhanced physical training. The main objective is to identify key advancements in sensor fusion technology, evaluate its application in VR systems and understand its impact on physical training.

Design/methodology/approach

The research initiates by providing context to the physical training environment in today’s technology-driven world, followed by an in-depth overview of VR. This overview includes a concise discussion on the advancements in sensor fusion technology and its application in VR systems for physical training. A systematic review of literature then follows, examining VR’s application in various facets of physical training: from exercise, skill development and technique enhancement to injury prevention, rehabilitation and psychological preparation.

Findings

Sensor fusion-based VR presents tangible advantages in the sphere of physical training, offering immersive experiences that could redefine traditional training methodologies. While the advantages are evident in domains such as exercise optimization, skill acquisition and mental preparation, challenges persist. The current research suggests there is a need for further studies to address these limitations to fully harness VR’s potential in physical training.

Originality/value

The integration of sensor fusion technology with VR in the domain of physical training remains a rapidly evolving field. Highlighting the advancements and challenges, this review makes a significant contribution by addressing gaps in knowledge and offering directions for future research.

Details

Robotic Intelligence and Automation, vol. 44 no. 1
Type: Research Article
ISSN: 2754-6969

Keywords

Article
Publication date: 12 December 2023

T.M. Jeyashree and P.R. Kannan Rajkumar

This study focused on identifying critical factors governing the fire response of prestressed hollow-core slabs. The hollow-core slabs used as flooring units can be subjected to…

Abstract

Purpose

This study focused on identifying critical factors governing the fire response of prestressed hollow-core slabs. The hollow-core slabs used as flooring units can be subjected to elevated temperatures during a fire. The fire response of prestressed hollow-core slabs is required to develop slabs with greater fire endurance. The present study aims to determine the extent to which the hollow-core slab can sustain load during a fire without undergoing progressive collapse under extreme fire and heating scenarios.

Design/methodology/approach

A finite element model was generated to predict the fire response of prestressed hollow core slabs under elevated temperatures. The accuracy of the model was predicted by examining thermal and structural responses through coupled temperature displacement analysis. A sensitivity analysis was performed to study the effects of concrete properties on prediction of system response. A parametric study was conducted by varying the thickness of the slab, fire and heating scenarios.

Findings

Thermal conductivity and specific heat of concrete were determined as sensitive parameters. The thickness of the slab was identified as a critical factor at a higher load level. Asymmetric heating of the slab resulted in higher fire resistance compared with symmetric heating.

Originality/value

This is the first study focused on studying the effect of modeling uncertainties on the system response by sensitivity analysis under elevated temperatures. The developed model with a parametric study helps in identifying critical factors for design purposes.

Details

Journal of Structural Fire Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2040-2317

Keywords

Book part
Publication date: 10 August 2023

Carlo S. Gutierrez

This chapter deals with family/household relevance as a stakeholder institution in rural (farm) communities. The data collection approach is qualitative. Families in Japan and the…

Abstract

This chapter deals with family/household relevance as a stakeholder institution in rural (farm) communities. The data collection approach is qualitative. Families in Japan and the Philippines’ rice-cultivating communities were the subjects of the study. Results revealed that households in the two sites were experiencing a unique ontological crisis vis-á-vis farming communities. The crisis pointed to the problem of farm families’ relegation as secondary stakeholders in the farming sector. Despite the struggle for survival in the farm sector, farm families were differently adaptive and enduring in dealing with the modern development – that is, selective technology adoption, farmland redefinition, struggle and resistance against farm policies, and community group accommodation, to name a few. This endurance contributes to farm family persistence as a relevant institution in Japan and the Philippines.

Details

Resilience and Familism: The Dynamic Nature of Families in the Philippines
Type: Book
ISBN: 978-1-80455-414-2

Keywords

1 – 10 of 364