17362 research outputs found
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Hydrological modelling of rainfall-runoff dynamics in the padas river basin: insights for water resources management
No full textWater resources are highly dependent on climatic variations and accurately quantifying the impacts of climate change on surface water availability is crucial for effective water resources management. This study explores the estimation of rainfallrunoff dynamics within the Padas River basin, an essential aspect of water resources planning and management. Utilizing the MIKE 11 NAM model, the research delves into the intricate processes governing catchment runoff, focusing on calibration and validation against observed streamflow data. The study encompasses flow duration curve analysis to elucidate flow rate distributions and river flow recurrence interval analysis to assess the likelihood of different flow magnitudes occurring over varied timeframes. Results reveal significant year-to-year variations in streamflow, emphasizing the dynamic nature of the basin's hydrological regime. Peak streamflow levels during the study period reached approximately 934.82 m³s-1, while the lowest flow averaged around 43 m³s-1. The recurrence intervals associated with specific flow rates, such as 5418.3 m³s-1 for a 100-year interval, provide critical insights for flood risk assessment and infrastructure design. These findings underscore the importance of informed decision-making and adaptive management strategies to ensure resilience against potential flood events in the Padas River basin. Overall, this study contributes to a comprehensive understanding of hydrological processes and associated risks, laying a foundation for sustainable water resources management and resilient infrastructure development in the region
The prediction of elastic modulus in sheet-reinforced composites using a homogenization approach
No full textBased on the equal-stress formula and equal-strain formula of material mechanics, a new formula for predicting Young’s modulus of sheet-reinforced composite is derived by taking sheet-graphene composite as an example. The effectiveness of the formula is verified by comparing it with the mixing rate (ROM), Halpin–Tsai equation, and finite-element simulation. This formula is used to discuss the effect of interface-layer properties on the modulus of composite materials. Compared with the case without interface, when the graphene content is 3% and the interface-layer properties are linearly distributed and exponentially distributed, respectively, the embedded RVE modulus prediction increases by 5.06%, and the sandwich RVE modulus prediction increases by 56.5% and 31.75%, respectively. The influence of the change in interface-layer thickness from 0 to 1.5 nm (determined according to the existing literature) is also discussed. The predicted modulus of embedded RVE and sandwich RVE increases by 73% and 11.3%, respectively. The results show that the influence of the thickness and properties of the interface layer on the modulus prediction of graphene composites cannot be ignored. Combined with the analysis of experimental data, it is found that the experimental data fall within the prediction range of the modulus of the formula, indicating that the formula can be used for the preliminary trend analysis of the mechanical test of graphene-composite materials in the early stage, saving testing costs and time
Anthropogenic impacts on bark and ambrosia beetle assemblages in tropical montane forest in northern Borneo
No full textAnthropogenic disturbances, such as forest conversion, have a profound impact on species distributions and biodiversity in tropical forests. This study aimed to determine the diversity and distribution of bark and ambrosia beetles (Curculionidae: Scolytinae and Platypodinae) across three forest types: Primary Forest (PF), Disturbed Forest (DF), and Rubber Plantation (RP) in southern Sabah, Malaysia. We analyzed biweekly data obtained from ethanol-baited traps over three years, from April 2017 to May 2020, which included 7257 individuals from 154 species. The dominant species remained the same across all forest types. However, species composition was highly stochastic and unpredictable between forest types. The abundance and number of species were highest in RP but lowest in DF. Indigenous forest use in DF mostly for fuel likely reduced the resources for the beetles. Open canopy structure in RP probably increased the number of flying beetles. Although adjacent to PF, RP displayed a distinct species composition predominantly associated with rubber trees. These findings underscore the anthropogenic impact on beetle assemblages due to forest use and emphasize the need for sustainable forest management practices to prevent biodiversity loss and maintain ecosystem stability
Roles of prostaglandins and cyclooxygenases in autism spectrum disorder: a comprehensive review
No full textPurpose of Review Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with multifaceted etiologies. Emerging evidence implicates dysregulation of prostaglandins and cyclooxygenase (COX) enzymes in ASD pathophysiology. This review aims to explore key mechanisms through which prostaglandins and COX enzymes may influence ASD. Recent Findings Recent research highlights significant roles for prostaglandins and COX enzymes in modulating Wnt (Wingless and Int-1) signalling pathways, which are known autism susceptibility pathways, as well as in regulating dendritic arborisation and cerebellar function. Polymorphisms in COX genes have also been linked to ASD, indicating a genetic component to this dysregulation. Furthermore, prostaglandins and COX enzymes show potential as biomarkers for ASD. Summary The accumulated evidence underscores the involvement of prostaglandins and COX enzymes in ASD pathophysiology. This insight offers a deeper understanding of the disorder and may pave the way for more effective diagnostic and treatment strategies
Nutritional profile comparison of Wild and Tagal indigenous Mahseer (Tor duoronensis) from Borneo perbandingan profil Nutrisi Mahseer Asli Liar dan Tagal (Tor duoronensis) dari Borneo
No full textLittle is known about the nutritional status of mahseer (Tor duoronensis), a high-value indigenous freshwater species of Borneo. The present study evaluated the proximate, fatty acid, and amino acid compositions in carcasses of juvenile wild and conserved (tagal system) mahseer. The crude lipid content of the wild-caught fish was significantly higher (P < 0.05) than tagal fish. Mahseer from tagal system contained significantly higher (P < 0.05) fatty acid concentrations of C14:0, C15:0, C16:0, C16.1, C17:0, C18:0, C18:1 n9t, C20:0, C20:4n6, C20:5n3, and C22:6n3, and lower concentrations of C12:0, C18:1 n9c, C18:2 n6c, C18:3 n3, C20:1, and C21:0 fatty acids than wild mahseer. The percentages of total saturated fatty acids and n-3:n-6 ratio were higher in the tagal system than in wild mahseer. Tor duoronensis harvested from the tagal system showed higher total amino acid concentration (756.74 ± 225.21 ng g-1) compared to wild fish (652.10 ± 249.50 ng g-1). Among the amino acid recorded, cysteine content was high in both wild (147.12 ± 206.62 ng g-1) and tagal fish (164.37 ± 229.39 ng g-1). Nine essential amino acids (histidine, arginine, threonine, valine, methionine, lysine, isoleucine, and phenylalanine) that are important in fish’s metabolic and physiological responses were present in both fish groups. This study indicates that the biochemical composition of Tor duoronensis was significantly influenced by their habitat, and these differences may be explained by the components of the fish’s diet. The information generated from this study is beneficial for developing nutritionally balanced practical feed for this species
New newton group Iterative methods for solving large-scale multi-objective constrained optimization problems
No full textWith the rapid development of big data and artificial intelligence technologies, we
are facing increasingly complex data and decision-making problems. Solving large-scale multiobjective constrained optimization problems can help to solve many practical engineering and
scientific problems. The weighted and Lagrange multiplier methods are considered to be classical
and effective methods for dealing with multiple objectives and constraints, but there are some
difficulties in solving the processed unconstrained optimization problems. The Newton method is
a commonly used method for solving this type of problem, but it requires a high computational
complexity. In order to solve these difficulties, we combine four methods such as the Weighted
method, Lagrange multiplier method, Newton method and Explicit Group Gauss-Seidel iterative
method to propose new Newton Group iterative methods such as 2 and 4-point Explicit Group
Gauss-Seidel iterative methods namely as Newton-2EGGS and Newton-4EGGS for solving largescale multi-objective constrained optimization problems. Also, the convergence analysis of the
proposed method is presented. To test the superiority of the proposed method by comparing the
computational results, the Newton-4EGGS iteration is more efficient than both Newton-2EGGS
iterative method and the Newton-Gauss-Seidel iterative method (Newton-GS), especially in terms
of the number of iterations and the computational time
Triboelectric nanogenerator based on tin doped zinc oxide and polyvinyl alcohol composite thin film for energy harvesting applications
No full textThe triboelectric nanogenerator (TENG) collects mechanical energy from its surroundings and converts it to electrical signals that can be used in sustainable energy harvesting technologies to help maintain the social ecosystem. However, TENG operation with pure triboelectric material may not be sufficient to power a small electronic system without modification. The optimal material capable of producing significant electrical energy with flexible structures remains a major barrier to practical application. In this study, tin-doped zinc oxide (Sn:ZnO) and polyvinyl alcohol (PVA) composite thin films were prepared using a simple solution immersion technique at various Sn atomic percentage (at.%) concentrations for use in TENG devices. The crystalline quality of a composite thin film made of Sn:ZnO and PVA was identified using x-ray diffraction. The microstructure changes of the composite thin film were found to be influenced by Sn doping, as studied using optical microscopy. The TENG with 2.5 at.% Sn:ZnO/PVA composite thin film and Kapton film achieved the highest peak voltage of 8.5 V in open circuit and 90 µW output power at 1 MΩ. The produced electrical output was then used to store energy in capacitors. According to its TENG properties, the Sn:ZnO/PVA composite thin film-based TENG has the potential to be used in low power electronic devices
Challenges in sustaining net zero buildings in Malaysia
No full textMalaysia aims to achieve net zero greenhouse gas (GHG) emissions by 2050. The insufficient awareness and comprehension of the net-zero building idea among the Malaysian populace has impeded the construction sector from realising its potential advantages. According to the Global Carbon Project data, Malaysia recorded 7.63 tonnes of carbon emissions per capita. This country also lacks adequate training and expertise in the installation of innovative technologies for net-zero energy buildings. The objective of this study is to investigate the challenges related to the maintenance of net zero buildings in Malaysia. This study uses a questionnaire as a research instrument for data collection. The poll received replies from 104 civil engineers. It conducted a descriptive analysis of the obtained data, assessing the mean and frequency of respondents' agreement. The results indicate that Malaysia's workforce has the lowest average score of 2.13, signifying a deficiency in knowledge concerning the skills necessary for sustainable construction practices. In contrast, the highest mean of 4.43 indicates a positive agreement about the effective integration of Malaysia's current technology into netzero construction projects. To attain the 2050 net zero objective, stakeholders in Malaysia, including government, industry, and the public, must enhance their understanding of net zero sustainability, promote the adoption of sustainable buildings to achieve net zero, and collectively assume responsibility for environmental conservation
Evaluating the validity of TPACK training module for University teachers in Qingdao: Insights from experts
No full textIn recent years, the rapid integration of technology and education has transformed teaching practices, highlighting the necessity for university teachers to develop the ability to effectively integrate technology, pedagogy, and content knowledge. Various TPACK capability enhancement trainings have emerged, but there are no unified standards for the quality of training content and the management of the training process. This study employs the expert scoring method to evaluate the TPACK (Technology, Pedagogy, and Content Knowledge) training module designed for teachers at Qingdao University. Using purposive sampling techniques, five experts in the field of TPACK were invited and consulted to evaluate the content, structure, and applicability of the modules through a systematic scoring process. The TPACK training module includes content from 6 units consisting of 19 sub-units, as well as the implementation plan for the training. The results of the study indicate that the TPACK training module received a high score for its effectiveness, reflecting its relevance and potential for improvement in higher education teaching practices. This research provides valuable insights into the evaluation of professional training modules for university teachers, emphasizing the importance of expert validation in ensuring the quality and effectiveness of such projects
A systematic review of knowledge sharing behaviour in Chinese virtual communities: Multilevel influencing factors
No full textThis study systematically reviews knowledge sharing behaviors in Chinese virtual communities, focusing on multi-level influencing factors and research contributions of Chinese scholars. Using a systematic literature review approach and following the PRISMA framework, this study analyzes 65 high-quality articles published between 2000 and 2023, which are selected from a comprehensive dataset of 1,515 records retrieved from the CNKI database and the CNKI Academic Database. These complementary data sources provide a balanced view of Chinese research disseminated domestically and internationally. The results show that influencing factors cover individual, team, and organizational levels. Individuallevel factors, such as self-efficacy, perceived usefulness, and altruism, are mainly positive, while perceived costs and neuroticism represent a minority of negative influences. Team-level factors, including trust and social network centrality, and organizational-level factors, such as rewards and cultural norms, further enhance knowledge sharing behaviors. Despite much attention paid to positive drivers, negative effects such as information overload and privacy concerns remain underexplored. In addition, emerging technologies with transformative potential, such as blockchain and artificial intelligence, have received little attention.This review highlights the interdisciplinary and evolving nature of research on knowledge sharing behavior in Chinese virtual communities. It explores research gaps, including the need to study negative factors and emerging technologies, laying the foundation for future theoretical and practical advances