24762 research outputs found
Sort by
Saved by the rook : a case of matchings and Hamiltonian cycles
No full textThe rook graph is a graph whose edges represent all the
possible legal moves of the rook chess piece on a chessboard. The problem
we consider is the following. Given any set M containing pairs of
cells such that each cell of the m1×m2 chessboard is in exactly one pair,
we determine the values of the positive integers m1 and m2 for which
it is possible to construct a closed tour of all the cells of the chessboard
which uses all the pairs of cells in M and some edges of the rook graph.
This is an alternative formulation of a graph-theoretical problem presented
in [1] involving the Cartesian product G of two complete graphs
Km1 and Km2 , which is, in fact, isomorphic to the m1×m2 rook graph.
The problem revolves around determining the values of the parameters
m1 and m2 that would allow any perfect matching of the complete graph
on the same vertex set of G to be extended to a Hamiltonian cycle by
using only edges in G.peer-reviewe
Rethinking political risk : history and prospects
No full textPURPOSE: We study the research question on the theory, policy and prospects of political risk
in international economics.DESIGN/METHODOLOGY/APPROACH: We follow a qualitative political economy analysis due to
the interdisciplinary nature of the question, and not only to the difficulties of measuring it.
Political risk can be an alteration or introduction of prohibitive taxation, embargoes, civil
wars, disbanding of licences, abduction of personnel or their families, expropriation and any
government actions that dissolve an agreement. The study introduces a few measurements of
political risk.FINDINGS: The study indicates the difficulties the definitions have innately. It argues that the
measurements are subjective and far from satisfactory in determining the extent of value of
political risk. Moreover, the subjective models use quite different approaches to determine
the risk. The problem is even more acute in the era of financialization, radical uncertainty
and the digital revolution. Today, business planning is not only difficult (by its very nature
long term) but also dominated by the operating framework of the global capital market
shaped by the technocrats of independent central banks and fund managers who impose
discipline on governments in their "market". The prospects for political risk seem to depend
on democratization, especially of the finance.PRACTICAL IMPLICATIONS: Since there is no theoretical model for the interpretation of political
risk, it is not scientifically valid for businesses to predict it within the framework of
(mainstream) economics alone. Hence, the limitation of quantitative answers. Strong
interdisciplinary gnoseology with a focus on political analysis and social change are
necessary as a complement to economics and institutions for rational business decisions.ORIGINALITY/VALUE: The paper contributes to the resurgent debate on the literature of
economic planning.peer-reviewe
First Pleistocene records of a colubrid snake and wall lizard Podarcis CF. Filfolensis (Bedriaga, 1876) (reptilia : Colubridae, Lacertidae) from Għar il-Fkieren (Fimbank Site), Malta
No full textGħar il-Fkieren is a solution pipe fissure discovered in 2010 during construction in Paceville, Malta,
which has yielded a significant Late Pleistocene fossil assemblage, dated to ca. 63 to 53,000 years
ago. Excavated by the Superintendence of Cultural Heritage, the 10-metre-deep fissure contained
Quaternary deposits rich in skeletal remains, including those of large vertebrates (cervids, tortoises,
avifauna) and microfauna, such as Microtus melitensis, Crocidura sicula, Bufotes viridis, and
Chiroptera. This study reports the first fossil evidence of a small colubrid snake and a wall lizard
(Podarcis cf. filfolensis) in Malta’s Pleistocene record, both identified through skeletal morphology.
These newly documented herpetofaunal taxa bridge gaps in the faunal record and offer new insights
into island endemism and faunal turnover from the Late Pleistocene to the Holocene.peer-reviewe
A comprehensive review of solar PV Integration with smart-grids : challenges, standards, and grid codes
No full textPromoting a sustainable and low-carbon energy future through the integration of renewable energy is essential, yet it presents significant challenges due to the intermittent nature of resources such as solar and wind. This paper examines the technological and economic dimensions of AC, DC, and smart grids, concentrating on the optimization of costs, efficiency, stability, and scalability. Smart grids, enhanced by AI, IoT, and blockchain technologies, play a vital role in energy management optimization, predictive maintenance, and secure energy transactions. Furthermore, the incorporation of renewable energy sources, especially photovoltaics, presents challenges including intermittency, voltage fluctuations, and grid congestion. This paper emphasizes the necessity for updated grid codes and policies that guarantee system stability and the effective functioning of renewable energy systems. The implementation of these regulatory frameworks is crucial for facilitating the efficient integration of renewable energy into the grid, ensuring a reliable and secure power supply while advancing sustainability efforts.peer-reviewe
A scoping review of sustainable strategies adopted in nuclear medicine
No full textIntroduction: Sustainable development is an approach that must be applied to all areas within healthcare, especially those in constant technological development, such as nuclear medicine. The aim of this study was to scope the literature to identify knowledge gaps in the sustainable development of the nuclear medicine field. Methods: The Joanna Briggs Institute methodology for scoping reviews was employed. A search strategy was conducted in PubMed, Embase, CINAHL and Web of Science in December 2024 using Mesh terms and keywords related to sustainability development and nuclear medicine. Three independent reviewers screened titles, abstracts, and full text. Four authors performed the data extraction and analysis. Results: A total of 36 studies met the inclusion criteria. The majority originated from Spain, and most were published in 2022 and 2023. Studies were categorised by procedure type: 33.3 % focused on therapy, 9.7 % on PET imaging, 33.3 % on diagnostic and therapeutic procedures, and 18.1 % on SPECT imaging. They were also categorised by location to include research conducted in hospital settings (n = 23), non-hospital settings (n = 8), both (n = 4) or none (n = 1). Reviewed studies implemented sustainability measures across the sustainability pillars: environmental (n = 30), economic (n = 12), and social (n = 9) pillars. Conclusion: This scoping review has highlighted the growing interest in sustainability, within the nuclear medicine field. Findings indicate that there is a strong emphasis on reducing environmental impact, with efforts such as waste minimisation, implementation of alternative discharge methods, and radionuclide extraction systems gaining popularity; however, further evidence is needed to understand the economic and social impact of nuclear medicine procedures. Implications for practice: The scoping review identified a range of strategies focused on mitigating the adverse impact on the environment and working towards efficient economic and social resources, to foster sustainable practices in nuclear medicine.peer-reviewe
Cultivating the linguistic garden : exploring the pedagogical approaches and challenges in teaching Maltese as a second language to international adults
No full textThis study investigates the challenges and pedagogical strategies in teaching Maltese as a second language (ML2) to international adults in Malta’s multilingual context. With both Maltese and English as official languages, the rise in migrant populations since 2014 has created a need for effective ML2 instruction, leading to the development of new teaching approaches and teacher training initiatives starting in 2018. Through qualitative research involving 36 experienced Maltese language teachers, the study examines the use of plurilingual approaches, the role of heritage languages in language transfer, and the challenges posed by the lack of digital resources, such as language-specific apps, films, and immersive technologies like virtual reality. Findings reveal the potential of leveraging learners’ first languages to aid comprehension, alongside the importance of inclusive strategies in multilingual classrooms. The study also identifies the urgent need for investment in digital tools and platforms to support learner engagement and autonomy. It concludes by emphasising the value of pedagogical innovation, enhanced digital access, and the strategic use of learners’ linguistic repertoires to strengthen outcomes in ML2 acquisition and integration.peer-reviewe
An enhanced rule-based fuzzy segmentation approach for automated urban feature extraction using high-resolution satellite imagery
No full textA fuzzy segmentation approach based on rule-based
fuzzy rules is proposed in this study to obtain urban features using
high-resolution satellite images. Multiresolution segmentation and
spectral difference segmentation are combined to effectively identify
and classify houses, roads, trees, and agricultural fields in urban
areas and rural farms.Afuzzy rule setwas developed using satellite
datasets from IKONOS, LISS IV, and WorldView-2, improving
classification accuracy. In this work, buildings were extracted
from IKONOS images, agricultural fields were extracted from
LISS IV images, and roads and vegetation were extracted from
WorldView-2 images. The map updating capability was demonstrated
for 1:2500 and 1:1000 scales, respectively, for buildings
and agricultural fields. Furthermore, the gray-level cooccurrence
matrix was employed to enhance classification reliability and mitigate
spectral confusion. By automating the process, the need for
additional GIS data is reduced, making it a cost-effective, scalable,
and efficient approach. Compared to traditional manual feature
extraction methods, this method is an effective alternative in urban
planning, land use mapping, and environmental monitoring.peer-reviewe
Camp on campus : love’s labour’s lost’s queer scholar
No full textThis article reconsiders Love’s Labour’s Lost in view of contemporary antagonisms between experts and nonexperts. The link is both thought-provoking and illuminating. The first section explores this tension as it emerges through Shakespeare’s inchoate figure of ‘the scholar’, at once upheld and undermined. Here, the scholar-figure hovers between common and elite, erudite and buffoonish, utterly refined and hopelessly base. ‘He’ is also distinctively set apart from ‘she’: the women of the play who prove themselves much more worldly than their wordy counterparts. The second section furthers this particularly gendered portrayal and follows Berowne’s peculiar navigation of this dichotomy, noting his camp queerness as an ironic paradox that functions beyond binary dualisms and which points, through queer failure, to a possible method of dismantling today’s corrosive political rhetoric.peer-reviewe
Practices of sun protection after skin cancer surgery in Malta
No full textBACKGROUND: Overexposure to Ultraviolet (UV) radiation is well known to be linked to the development of skin cancer. Our study aims to identify changes in patient practices after being diagnosed with skin cancer. Moreover, we identify areas of improvement which clinicians and health care staff can work on to improve patient awareness of harmful effects of UV radiation.METHODS: 97 patients who had a skin cancer procedure at the Plastic Surgery and Burns Unit at Mater Dei Hospital, from January to March 2020, were included. Questionnaires were sent out, the data was anonymized and then inputted into an excel sheet.RESULTS: A response rate of 63.9% was obtained. 51% of the patients stated that they avoided midday sun exposure before and after their surgical procedure and 24% started avoiding the midday sun after their cancer diagnosis. 48% of the patients used sun protective accessories before and after their surgery, 16% started using them after their surgery and 32% do not use accessories to protect themselves from the sun. 33% of the patients used sunblock before and after the procedure, 22% of them claimed that they started using sunblock after the surgery but 45% of them said that they do not use sunblock at all.CONCLUSION: This study shows that a number of skin cancer patients are still not aware of the dangers of sun exposure. Therefore, more work needs to be done locally, not only in terms of primary prevention but also in secondary prevention following a skin cancer intervention.peer-reviewe
Using hydro-pneumatic energy storage for improving offshore wind-driven green hydrogen production — a preliminary feasibility study in the central Mediterranean Sea
Get PDFThis paper presents a preliminary feasibility study for integrating hydro-pneumatic energy storage (HPES) with off-grid offshore wind turbines and green hydrogen production facilities—a concept termed HydroGenEration (HGE). This study compares the performance of this innovative concept system with an off-grid direct wind-to-hydrogen plant concept without energy storage, both under central Mediterranean wind conditions. Numerical simulations were conducted at high temporal resolution, capturing 10-min fluctuations of open field measured wind speeds at an equivalent offshore wind turbine (WT) hub height over a full 1-year, seasonal cycle. Key findings demonstrate that the HPES system of choice, namely the Floating Liquid Piston Accumulator with Sea Water under Compression (FLASC) system, significantly reduces Proton Exchange Membrane (PEM) electrolyser (PEMEL) On/Off cycling (with a 66% reduction in On/Off events), while maintaining hydrogen production levels, despite the integration of the energy storage system, which has a projected round-trip efficiency of 75%. The FLASC-integrated HGE solution also marginally reduces renewable energy curtailment by approximately 0.3% during the 12-month timeframe. Economic analysis reveals that while the FLASC HPES system does introduce an additional capital cost into the energy chain, it still yields substantial operational savings exceeding EUR 3 million annually through extended PEM electrolyser lifetime and improved operational efficiency. The Levelized Cost of Hydrogen (LCOH) for the FLASC-integrated HGE system, which is estimated to be EUR 18.83/kg, proves more economical than a direct wind-to-hydrogen approach with a levelized cost of EUR 21.09/kg of H2 produced. This result was achieved through more efficient utilisation of wind energy interfaced with energy storage as it mitigated the natural intermittency of the wind and increased the lifecycle of the equipment, especially that of the PEM electrolysers. Three scenario models were created to project future costs. As electrolyser technologies advance, cost reductions would be expected, and this was one of the scenarios envisaged for the future. These scenarios reinforce the technical and economic viability of the HGE concept for offshore green hydrogen production, particularly in the Mediterranean, and in regions having similar moderate wind resources and deeper seas for offshore hybrid sustainable energy systems.peer-reviewe