bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhanced Gain Dual-Port Compact Printed Meandered Log-Periodic Monopole Array Antenna Design with Octagonal-Ring Shaped FSS for Broadband 28 GHz Applications
Authors: Gültekin Seyfettin Sinan , Yerlikaya Mehmet 
Published: June 2024

AbstractIn this article, we propose a microstrip-fed printed meandered log-periodic monopole array (PMLPMA), and its dual-port configuration incorporating an octagonal ring frequency selective surface (FSS) layer. The dual-port PMLPMA antenna system has a compact structure with a total dimension of 18.75 × 18.75 mm2 and is designed to operate in the 5G n257 (28 GHz) band. The proposed PMLPMA radiator consists of five log-periodic monopole array elements, and the dual-port antenna system comprises two identical PMLPMAs placed vertically next to each other. Additionally, an octagonal ring-shaped single-layer FSS was implemented on the proposed antenna system to increase the gain across the operational band. Simulation results demonstrate that the dual-port PMLPMA antenna achieves a peak gain of about 3.5 dBi without the FSS layer, while a peak gain of 7.35 dBi is achieved when the FSS layer is augmented on the antenna. Moreover, isolation levels exceeding 30 dB are obtained for both cases between the 26.5–29.5 GHz frequency ranges. To verify the simulation results, the dual-port PMLPMA antenna system, and the octagonal ring-shaped FSS layer are also prototyped. The measurements align closely with the simulations in terms of performance criteria such as gain, bandwidth, and radiation patterns. Thus, the 28 GHz band antenna system exhibits great potential for 5G mobile applications.
Microstructural Analysis of Low-Calcium Fly Ash-Based Geopolymer Concrete with Different Ratios of Activator and Binder Under High Temperatures
Authors: Kucukgoncu Hurmet , Özbayrak Ahmet 
Published: June 2024

AbstractGeopolymer concretes have emerged as an alternative to traditional Portland cement concretes with high strength, good durability, well corrosion performance and high-temperature resistance, and being a sustainable and environmentally friendly material. In this study, a comprehensive microstructural analysis of low-calcium fly ash-based geopolymer concrete samples with different alkali activator to binder ratios was conducted after exposure to temperatures ranging from 400 to 800 °C. The experimental results of the geopolymer concrete specimens found out significant findings, including a notable loss of mass and an approximate 80% decrease in compressive strength after exposure to 800 °C. The microstructural analysis underlined crack formation, voids and porosities in the geopolymer matrix at elevated temperatures, affecting the physical and mechanical properties of the material. The study presents significant insights into the behaviour of low-calcium fly ash-based geopolymer concrete with different binder and alkali activator ratios under high temperatures, revealing the performance of geopolymer concretes in extreme environments and the effect of incompatibility between geopolymer concrete and aggregate due to thermal temperature effects on this performance.
An interdisciplinary approach for successful municipal energy transition communication
Authors: Palm Herbert , Pfeffer Hannah , Raith Natallia , Brandstetter Nicole 
Published: June 2024

AbstractThe energy transition toward a sustainable, decentralized energy supply requires the active participation of local municipalities. Its success depends on acceptance and participation across all sections of the population. A role-specific communication strategy is therefore essential to meet the different communication and information habits, value systems, and needs. In this study, a corresponding transactional communication approach is proposed and evaluated, in which communication is understood as a dynamic and interactive process that is oriented toward preference-specific roles. The methodological approach transfers both Jakobson’s communication model from linguistics and Freeman’s matrix from stakeholder management to the context of municipal energy transition communication. In line with our newly proposed agile reference process, a contextualization-based instead of a predominantly functionally oriented energy transition communication strategy can thus be formulated. Applying Jakobson’s model, roles are described primarily in terms of their communicative aspects rather than their functional meaning. The new interdisciplinary approach is demonstrated using the example of a municipality. Results are used to demonstrate a role-specific communication strategy as the base of the subsequent derivation of role-specific actions and instruments.
An Integrated Perspective of Effort and Perception of Effort
Authors: Halperin Israel , Vigotsky Andrew D. 
Published: June 2024

AbstractEffort and the perception of effort (PE) have been extensively studied across disciplines, resulting in multiple definitions. These inconsistencies block scientific progress by impeding effective communication between and within fields. Here, we present an integrated perspective of effort and PE that is applicable to both physical and cognitive activities. We define effort as the energy utilized to perform an action. This definition can be applied to biological entities performing various voluntary or involuntary activities, irrespective of whether the effort contributes to goal achievement. Then, we define PE as the instantaneous experience of utilizing energy to perform an action. This definition builds on that of effort without conflating it with other subjective experiences. We explore the nature of effort and PE as constructs and variables and highlight key considerations in their measurement. Our integrated perspective aims to facilitate a deeper understanding of these constructs, refine research methodologies, and promote interdisciplinary collaborations.
Transitioning to Online Instructions and COVID-19 Response: A View from Mining Emergent College Students Discourse in Online Discussion Forum
Authors: Lin Yiwen , Nixon Nia 
Published: June 2024

AbstractThe COVID-19 pandemic disrupted teaching and learning activities in higher education around the world. As universities shifted to remote instruction in response to the pandemic, it is important to learn how students engaged in learning during this challenging period. In this paper, we examined the changes in learners’ social and cognitive presence in online discussion forums prior and after remote instruction. We also extracted emergent topics during the pandemic as an attempt to explore what students talked about and how they interacted with their peers. We extracted discussion forum posts between 2019 and 2020 from courses that have been offered repeatedly each term at a four-year university in the U.S. Our findings suggest that students exhibited higher social presence through increased social and affective language during remote instructions. We also identified emergent COVID-19 related discourse, which involved sharing personal experience with positive sentiments and expressing opinions on contemporary events. Our qualitative analysis further revealed that students showed rapport and empathy towrads others, and engaged in active sense making of the pandemic through engaging in critical discourse. Our study sheds lights on leveraging discussion forum to facilitate learner experiences and building classroom community in online courses. We further discussed the potential for conducting large-scale computational linguistic modeling on learner discourse and the role of artificial intelligence in deriving insights on learning behavior at scale to support remote teaching and learning.
Unravelling the Web: The Internet’s Double-Edged Impact on COVID-19 Dynamics
Authors: Alfano Vincenzo 
Published: June 2024

AbstractThe intricate relationship between Internet access, freedom, and the spread of COVID-19 during the pandemic remains a crucial topic, important both for understanding what happened and for improving the response to future crises. This study investigates the impact of the share of Internet users, and its relationship with Internet freedom, on the COVID-19 transmission rate, addressing research questions regarding the interplay between these factors. Analyzing a panel dataset of 60 countries during the first wave, hybrid F-GLS models reveal that an increased number of Internet users correlates with a larger number of new daily COVID-19 cases. Conversely, the interaction between Internet users and net freedom attenuates the positive relationship between users and case counts, implying that the latter has a moderating role. These findings emphasize the multifaceted nature of the Internet’s influence on pandemic dynamics, and highlight how it acts both as a facilitator and a constraint.
Development of novel proton exchange membranes based on cross-linked polyvinyl alcohol (PVA)/5-sulfosalicylic acid (SSCA) for fuel cell applications
Authors: Elerian Ahmed F. , Mohamed AbdAllah A. , Elnaggar Elsayed M. , Abu-Saied M. A. 
Published: June 2024

AbstractThe proton-conducting and methanol permeation behaviors of polymeric electrolyte membranes (PEMs), as well as the expensive nature of direct methanol fuel cell (DMFC) components, pose major concerns in DMFC performance and commercialization. As a result, this research aimed to develop low-cost polyelectrolyte membranes based on cross-linked poly(vinyl alcohol)/5-sulfosalicylic acid dehydrate (PVA/SSCA) composite. Chemical cross-linkers and modifiers offer the essential chemical and mechanical stability of the developed membranes for usage as polyelectrolyte membranes (PEMs). The manufactured composite proton exchange membranes provide several benefits, including significant thermal, chemical, and mechanical stability. The results revealed that extending the SSCA molar concentration increased IEC outcomes of the synthesized membranes, reaching an elevated level of (3.31 meq g−1) compared to (0.91 meq g−1) for the Nafion 117 membrane. The proton conductivity of a composite membrane (102 μm thick) measured by impedance spectroscopy was relatively (0.078 S cm−1) and found comparable to other PVA-based composite membranes reported in the literature. Other key parameters, such as methanol permeability, were measured for constructed composite proton exchange membranes (2.52 × 10–7 cm2 s−1), which were much lower than Nafion 117 (3.39 × 10–6 cm2 s−1). The Fourier transform infrared (FT-IR), Raman scattering spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, elemental analysis, and thermal gravimetric analysis (TGA) were among the techniques used to characterize the synthesized membranes. These characterizations confirm the structural interaction between the membrane components’ crystalline nature, and no signs of phase separation or cracks were found; surface morphology and good membrane homogeneity, elemental analysis, and the membranes’ thermal stability (up to 290 °C). The membranes were also mechanically characterized using a universal testing machine (UTM), which revealed good mechanical stability. The findings demonstrate that a low-cost proton exchange membrane could potentially be synthesized for DMFC applications.
Fibroblastic tissue growth on polymeric electrospun membranes: a feasibility study
Authors: Osório Luana A. , Naveenathayalan Angel , Silva Elisabete , Mackay Ruth E. 
Published: June 2024

AbstractIn recent years the interest in synthetic scaffolds has increased significantly as an alternative to animal-derived materials, as well as the advancement of material and manufacturing engineering, has resulted in improved standardisation and reproducibility within the field. Despite these advancements, a significant amount of research on animal-derived scaffolds, whilst research on synthetic materials is lacking for the growth of non-tumourgenic breast cell lines. The main objective of this work is to manufacture biodegradable scaffolds using biocompatible materials such as PVA (Polyvinyl Alcohol), PU (Polyurethane), Ge (Gelatin) and PCL (Poly-(-caprolactone) to test human cell adhesion and investigate the optimal system that supports representative tissue organisation and that could be used as an alternative to Matrigel™. Here, human mammary fibroblasts (HMF) were used as proof of concept. The membranes were manufactured using the process of electrospinning and characterised by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (ATR-FTIR), contact angle, tensile strength, and degradation studies. The assessment of the membranes as a viable biomaterial for the growth and development of cells was studied by MTT proliferation assay, fluorescence microscopy and SEM imaging. Results demonstrate that all materials are suitable for HMF proliferation. However, from microscopy analysis, only PU and PVA membranes induced morphological organisation of HMF similar to those results obtained in the Matrigel™ control conditions. This feasibility study reveals that HMF organisation, and proliferation are affected by the properties of the scaffold. Consequently, scaffolds parameters should be adjusted and manipulated to impact cell behaviour and emulate in vivo conditions.
Optimizing delivery routes for sustainable food delivery for multiple food items per order
Authors: Thipparthy Kaushika Reddy , Khalaf Mohammed I. , Yogi Kottala Sri , Alghayadh Faisal Yousef , Yusupov Akhmadbek , Maguluri Lakshmana Phaneendra , Ofori-Amanfo Paul 
Published: June 2024

AbstractThe diversity of consumer demand for take-out food has led to the characteristic structure of one order with multiple items, where the different food items in a single order are provided by two or more merchants. In the context of multi-item delivery for take-out orders with time windows, this study investigates vehicle routing for order delivery. This research aims to improve the service level of merchants and the efficiency of delivery vehicles. Food vendors receive orders from consumers through online platforms, then package the food items according to the orders. This method is a preliminary exploration of the issue of fulfilment of takeout orders on online platforms, and can provide preliminary theoretical support for decision-making on the delivery process of takeout orders on online platforms. In the context of online catering sales platforms and offline food sales merchants, this paper studies the delivery problem of takeaway orders with a time window and the characteristics of one order and multiple items, and constructs a method that takes the order delivery time requirements into account and minimizes the total order fulfilment cost. Taking into account the time window constraints of both physical restaurants and consumers, genetic algorithms are utilized to solve the order delivery problem. Finally, through case studies and experiments, the effectiveness and feasibility of the mathematical model are validated. Practical recommendations and insights are provided from the perspective of management and route planning.
The effect of Fernblock® in preventing blue-light-induced oxidative stress and cellular damage in retinal pigment epithelial cells is associated with NRF2 induction
Authors: Gallego-Rentero María , López Sánchez Ana , Nicolás-Morala Jimena , Alcaraz-Laso Paula , Zhang Noelia , Juarranz Ángeles , González Salvador , Carrasco Elisa 
Published: June 2024

AbstractBlue light exposure of the ocular apparatus is currently rising. This has motivated a growing concern about potential deleterious effects on different eye structures. To address this, ARPE-19 cells were used as a model of the retinal pigment epithelium and subjected to cumulative expositions of blue light. The most relevant cellular events previously associated with blue-light-induced damage were assessed, including alterations in cell morphology, viability, cell proliferation, oxidative stress, inflammation, and the induction of DNA repair cellular mechanisms. Consistent with previous reports, our results provide evidence of cellular alterations resulting from repeated exposure to blue light irradiation. In this context, we explored the potential protective properties of the vegetal extract from Polypodium leucotomos, Fernblock® (FB), using the widely known treatment with lutein as a reference for comparison. The only changes observed as a result of the sole treatment with either FB or lutein were a slight but significant increase in γH2AX+ cells and the raise in the nuclear levels of NRF2. Overall, our findings indicate that the treatment with FB (similarly to lutein) prior to blue light irradiation can alleviate blue-light-induced deleterious effects in RPE cells, specifically preventing the drop in both cell viability and percentage of EdU+ cells, as well as the increase in ROS generation, percentage of γH2AX+ nuclei (more efficiently with FB), and TNF-α secretion (the latter restored only by FB to similar levels to those of the control). On the contrary, the induction in the P21 expression upon blue light irradiation was not prevented neither by FB nor by lutein. Notably, the nuclear translocation of NRF2 induced by blue light was similar to that observed in cells pre-treated with FB, while lutein pre-treatment resulted in nuclear NRF2 levels similar to control cells, suggesting key differences in the mechanism of cellular protection exerted by these compounds. These results may represent the foundation ground for the use of FB as a new ingredient in the development of alternative prophylactic strategies for blue-light-associated diseases, a currently rising medical interest.
Burden of care and mental health of informal caregivers of children with developmental disabilities in Sub-Saharan Africa: the moderating role of resilience
Authors: Chukwuemeka Nkechi Angela , Obioha Wisdom Chidiebere 
Published: June 2024

AbstractCaregivers play the most important role in the care of children with developmental challenges. The care received by children with developmental disabilities from caregivers is essential and indispensable as these children will not function well without such care. However, caregiver characteristics and factors internal to the caregivers, such as their state of mental health or ability to adapt to caregiving stress, may impact the quality of care that they give to these children and require attention. Therefore, we investigated the unique contributions of resilience and burden of care on the mental health of informal caregivers of children with developmental disabilities (N = 228, 165 females, 63 males, mean age = 27.85, SD = 10.02) aged between 16 to 67 years old. Additionally, we examined whether resilience would moderate the association between the burden of care and mental health. The Connor-Davidson Resilience Scale, Zarit Burden Interview, and General Health Questionnaire were used to collect data from the caregivers. The data were then analysed using Pearson correlation and the Hayes PROCESS module in SPSS 27. The results indicated that burden of care was negatively associated with mental health, while resilience was positively associated with mental health. The result further indicated that resilience did not significantly moderate the association between the burden of care and mental health. The study concludes that resilience is a potential protective factor for the mental health of caregivers and should be the target of interventions that seek to improve the quality of care for children with developmental disabilities.
Interannual Variation and Trend of Carbon Budget Observed for More Than Two Decades at Takayama in a Cool‐Temperate Deciduous Forest in Central Japan
Authors: Murayama Shohei , Kondo Hiroaki , Ishidoya Shigeyuki , Maeda Takahisa , Saigusa Nobuko , Yamamoto Susumu , Kamezaki Kazuki , Muraoka Hiroyuki 
Published: June 2024

AbstractLong‐term carbon dioxide (CO2) flux measurements between the atmosphere and the ecosystem have been made since 1993 at a cool‐temperate deciduous forest site (Takayama) in Japan influenced by the Asian Monsoon, constituting the longest data set among all the AsiaFlux sites. Interannual variations (IAVs) and trends in the annual carbon budget components and related environmental factors were examined. Annual net ecosystem production (NEP) (mean ± 1σ) during the period of eddy covariance measurements in 1999–2021 was 265 ± 86 gC m−2 yr−1, and its IAV was dependent more on gross primary production (GPP) than on ecosystem respiration. The annual NEP and GPP were correlated with the monthly mean NEP, GPP and leaf area index from June to September, as well as with the length of the net carbon uptake period. Significantly increasing and decreasing trends in the annual NEP and GPP were detected during 2004–2013 and 2013–2021, respectively. The increasing trends were mainly caused by the vegetation recovery from typhoon disturbances. On the other hand, although the cause of the decreasing trends was not clearly identified, recent extreme weather events and/or forest succession might be related to the trends. Significant positive correlations between the start and the end of the net carbon uptake period, and between the leaf expansion and leaf fall were found. These may be attributed to phenological characteristics and negative correlation between air temperature in spring and solar radiation in early fall associated with ENSO events that can also influence IAVs in annual NEP and GPP.
Soil and Atmospheric Drought Explain the Biophysical Conductance Responses in Diagnostic and Prognostic Evaporation Models Over Two Contrasting European Forest Sites
Authors: Mallick Kanishka , Sulis Mauro , Jiménez‐Rodríguez Cesar Dionisio , Hu Tian , Jia Aolin , Drewry Darren T. 
Published: June 2024

AbstractDiagnosing and predicting evaporation through satellite‐based surface energy balance (SEB) and land surface models (LSMs) faces challenges due to the non‐linear responses of aerodynamic (ga) and stomatal conductance (gcs) to concurrent soil and atmospheric drought. Despite a soaring popularity to refine gcs formulation in LSMs by integrating soil‐plant hydraulics, SEB models often overlook the utility of gcs. This oversight is attributed to the overriding emphasis on reducing ga uncertainties and the lack of coordination between these two modeling communities. This disengagement between modeling communities poses a persistent challenge in understanding divergent evaporation estimates during intense soil‐atmospheric drought. Here we conducted a theoretical experiment over two contrasting European forest sites to examine the sensitivity of conductances and evaporative fluxes to a water‐stress factor (β‐factor), coupled with land surface temperature (LST) and vapor pressure deficit (representing soil and atmospheric drought proxy). Utilizing a non‐parametric diagnostic model (Surface Temperature Initiated Closure, STIC) and a prognostic model (Community Land Model, CLM5.0), the analysis revealed that the β‐factor, alongside different functional forms of conductances and the loose coupling of CLM5.0 conductances to LST, significantly influenced the response of the two models to soil and atmospheric drought. These discrepancies propagated in the estimates of evaporative fluxes between STIC and CLM5.0. The analysis reaffirms the need for a consensus on theory and models capturing the sensitivity of biophysical conductances to soil‐atmospheric drought interplay. It emphasizes the need for fostering collaboration between modeling communities to enhance the prediction of evaporation in complex environmental conditions.