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The persistent shadow of the supermassive black hole of M87
Get PDFThe Event Horizon Telescope (EHT) observation of M87∗ in 2018 has revealed a ring with a diameter that is consistent with the 2017 observation. The brightest part of the ring is shifted to the southwest from the southeast. In this paper, we provide theoretical interpretations for the multi-epoch EHT observations for M87∗ by comparing a new general relativistic magnetohydrodynamics model image library with the EHT observations for M87∗ in both 2017 and 2018. The model images include aligned and tilted accretion with parameterized thermal and nonthermal synchrotron emission properties. The 2018 observation again shows that the spin vector of the M87∗ supermassive black hole is pointed away from Earth. A shift of the brightest part of the ring during the multi-epoch observations can naturally be explained by the turbulent nature of black hole accretion, which is supported by the fact that the more turbulent retrograde models can explain the multi-epoch observations better than the prograde models. The EHT data are inconsistent with the tilted models in our model image library. Assuming that the black hole spin axis and its large-scale jet direction are roughly aligned, we expect the brightest part of the ring to be most commonly observed 90 deg clockwise from the forward jet. This prediction can be statistically tested through future observations
On products of prime element orders in finite groups
No full textLet be a finite group. The functions and denote the sum of the element orders and the sum of the prime element orders of , respectively. Significant results related to the study of these functions have been published recently. Further, the function was introduced to denote the product of the element orders of . We introduce \nrs(G), which denotes the product of the prime element orders of a finite group . We find a lower bound for \nrs on the set of groups of the same order and deduce a result on nilpotent groups using \nrs
UX Values Framing: An Authoring Tool To Capture Children's Values for Widening Narratives
No full textThis study highlights a value-led investigation into children’s (aged 9–18) views on decolonising museum experiences. The paper presents the challenges and opportunities associated with using a low-fidelity Augmented Reality authoring tool (User Experience Values Framing) to personalise museum experiences. The tool captures children’s values by employing a Value Sensitive Design approach, in addressing issues of representation, power imbalances, and cultural responsiveness in museum technologies. Through four empirical studies, the research examines the motivations behind visiting museums, value preferences, and the emergence of values amongst children. It sheds light on the effectiveness of involving children in the design process of an Augmented Reality authoring tool, highlighting their perspectives on decolonisation narratives and the desire for personalised and inclusive museum experiences. The studies highlight the importance of capturing and integrating values related to decolonisation into museum exhibition design, emphasising the needs and preferences of young audiences. Despite limitations, the insights gained offer valuable guidance for museums seeking to create more inclusive and equitable cultural exhibitions
For a Cinema After Nature: Jacques Perconte and the Art of Withdrawal
No full textThe ‘ontological turn’ has deconstructed the concept of nature, and the work of thinkers such as Philippe Descola, Bruno Latour, or Donna Haraway suggests new paradigms in which we situate ourselves and our presence in a world ‘after nature’. What about film? How to think a cinema after nature? How can film engage with the world without reproducing regimes of organization, and distributions of power, inherited from the systems of dual oppositions constructed around the concept of nature (e.g., visible and invisible, seer and seen, subject and object, shot and reverse shot, absence and presence)? How could a possible ‘cinema after nature’ acknowledge the agency of all things, whatever they are, that signal themselves at different moments of the film's elaboration and give them the possibility to ‘make film’ as they “make world”
The efficacy of dietary supplements on health status and performance of football players: a systematic review
No full textThis study aimed to review the efficacy of commonly used supplements on the health status and performance of football players. We searched several databases for relevant publications published in English up to June 2024 using keywords such as nutritional supplementation, performance, football, and football players. The available literature indicated that l-arginine supplements may improve cardiovascular function, ventilation, the serum level of lactate, and maximal oxygen consumption (VO2 Max) of football players. Branched-chain amino acids (BCAAs) may improve multiple-choice reaction time. Creatine supplements improve jumping, sprinting, change of direction speed, and reduce fatigue. Among the vitamins, vitamin D improves the serum level of injury-related hormones such as cortisol and testosterone. B vitamins reduce the level of blood lactate in the recovery periods. Vitamin E and vitamin C may improve performance by decreasing oxidative stress and increasing the antioxidant capacity and oxygen delivery to exercising skeletal muscles. Iron supplementation improves endurance capacity. Further studies are warranted to confirm the effects of the supplements on football players, to identify the appropriate dosage of the supplements and also to determine their mechanism of action
Utilization of thermal plasma decomposed municipal solid waste bottom ash as partial cement and fine aggregates replacements on cement mortar properties
No full textThis study examines the synergistic effects of bottom ash in mortar production. The bottom ash used in the study was derived from thermal plasma decomposition of municipal solid waste. In the first part of the study, mortars were prepared with varying levels of ash as replacements: 5 %, 10 %, and 15 % for cement replacement and 15 % for sand replacement. The results reveal that using ash as a cement replacement reduces workability by 6.53–13.40 %, compressive strength by 10.93–24.15 %, flexural strength by 12.23–35.55 %, and increases water absorption by 0.79–26.11 % compared to the control. However, ash content of 5–10 % reduces porosity by 2.73–4.32 %. In the second part, washed and unwashed ash was used as a sand substitute at levels of 10–30 % in mortar. Incorporating 10–20 % ash improves compressive strength by up to 14 % and exhibits a slight enhancement in flexural strength, lower porosity, and lower water absorption. Interestingly, only unwashed ash enhances mechanical strengths without affecting porosity and water absorption. These findings demonstrate the potential of bottom ash in improving mortar properties. However, further research and optimization are recommended to maximize the environmental benefits and overall performance of mortar production
Integrating SMEs market and technology orientation: an exploration of digital technological opportunism, agility, future focus and performance
No full textPurpose
Drawing on the resource-based and dynamic capabilities framework, the study examines the influence of market and technology orientation on digital technological opportunism to understand SMEs' future focus and organizational performance given the digital transformation landscape for international expansion.
Design/methodology/approach
Partial-least-square structural equation modeling was employed to examine the hypothesized relationships using cross-sectional survey data from 322 senior and middle-level executives.
Findings
The findings highlight the fact that market and technology orientation capabilities positively influence SMEs’ digital technological opportunism, which is shown to positively influence organizational performance by developing a future focus on digital marketing strategy development in the internationalization process.
Originality/value
The research provides valuable insights into integrating market and technology orientation with digital technological opportunism in SMEs to develop future focus and achieve organizational performance for international expansion
“Blue tastes like salt. It just does”: Exploring generational differences in the construction of cross-sensory metaphors
Get PDFMetaphors improve communication between children and adults, which can be challenging due to differences in experiences. Cross-sensory metaphors convey qualities associated with one sense using terms from another, e.g. a “sharp smell” and could thus improve generational communication by bridging differences in sensory cognition. We observed children (8-11yrs, n=65), young adults (18-24yrs, n=51) and older adults (60-85yrs, n=38) playing Sense-O-Nary, a variation of Pictionary where players construct and interpret cross-sensory metaphors, and analysed differences in metaphor type, degree of elaboration, and association strategies. We found that children relied on “familiar experiences” for metaphor construction, while adults used more diverse association strategies. Degree of elaboration was consistent across ages for tactile and visual stimuli but differed for olfactory stimuli. All groups used “active” metaphors most commonly, but children showed more use of “implicit”, “similes”, and “personification”. We present designs that demonstrate how these characterisations could be leveraged to improve intergenerational communication
The palaeoenvironmental potential of bioarchaeological isotope data
Get PDFBioarchaeology not only provides insights into human, animal, and environmental ecology, but also generates huge amounts of stable and radiogenic isotope data that are not well recognised by other disciplines. Here, we present potential avenues for the integration and interpretation of archaeological isotope data into environmental studies. We emphasise the large spatio-temporal scales on which isotope patterns can be observed, for example using isoscapes, the limitations and potential pitfalls that come with isotope data from archaeological research, and future cross-disciplinary collaborations between bioarchaeology and other palaeo-disciplines