bluuebunny/crossref_metadata_2025 huggingface dataset:
Unambiguous Wind Direction Estimation Method for Shipborne HFSWR Based on Wind Direction Interval Limitation
Authors: Zhang Yunfeng , Wang Yiming , Ji Yonggang , Li Ming
Published: June 2023

Due to its maneuverability and agility, the shipborne high-frequency surface wave radar (HFSWR) provides a new way of monitoring large-area marine dynamics and environment information. However, wind direction ambiguity is problematic when using monostatic shipborne HFSWR for wind direction inversion. In this article, an unambiguous wind direction measurement method based on wind direction interval limitation is proposed. The two first-order spectral wind direction estimation methods are first presented using the relationship between the normalized amplitude differences or ratios of the broadened Doppler spectrum and the wind direction. Moreover, based on the characteristic of a small wind direction estimation error in a large included angle between the spectral wind direction and the radar beam, the wind direction interval is obtained by counting the distribution of radar-measured wind direction within this included angle. Furthermore, the eliminated ambiguity of wind direction is transformed to judge the relationship between the wind direction interval and the two curves, which represent the relationship between the spreading parameter and the wind direction. Therefore, the remote sensing monitoring of ocean surface wind direction fields can be realized by shipborne HFSWR. The simulation results are used to evaluate the performance of the proposed method and the multi-beam sampling method for wind direction inversion. The experimental results show that the errors of wind direction estimated by the multi-beam sampling method and the equivalent dual-station model are large, and the proposed method can improve the accuracy of wind direction measurement. Three widely used wave directional spreading models have been applied for performance comparison. The wind direction field measured by the proposed method under a modified cosine model agrees well with that observed by the China-France Oceanography Satellite (CFOSAT).
Load Balancing Using Artificial Intelligence for Cloud-Enabled Internet of Everything in Healthcare Domain
Authors: Aqeel Ibrahim , Khormi Ibrahim Mohsen , Khan Surbhi Bhatia , Shuaib Mohammed , Almusharraf Ahlam , Alam Shadab , Alkhaldi Nora A.
Published: June 2023

The emergence of the Internet of Things (IoT) and its subsequent evolution into the Internet of Everything (IoE) is a result of the rapid growth of information and communication technologies (ICT). However, implementing these technologies comes with certain obstacles, such as the limited availability of energy resources and processing power. Consequently, there is a need for energy-efficient and intelligent load-balancing models, particularly in healthcare, where real-time applications generate large volumes of data. This paper proposes a novel, energy-aware artificial intelligence (AI)-based load balancing model that employs the Chaotic Horse Ride Optimization Algorithm (CHROA) and big data analytics (BDA) for cloud-enabled IoT environments. The CHROA technique enhances the optimization capacity of the Horse Ride Optimization Algorithm (HROA) using chaotic principles. The proposed CHROA model balances the load, optimizes available energy resources using AI techniques, and is evaluated using various metrics. Experimental results show that the CHROA model outperforms existing models. For instance, while the Artificial Bee Colony (ABC), Gravitational Search Algorithm (GSA), and Whale Defense Algorithm with Firefly Algorithm (WD-FA) techniques attain average throughputs of 58.247 Kbps, 59.957 Kbps, and 60.819 Kbps, respectively, the CHROA model achieves an average throughput of 70.122 Kbps. The proposed CHROA-based model presents an innovative approach to intelligent load balancing and energy optimization in cloud-enabled IoT environments. The results highlight its potential to address critical challenges and contribute to developing efficient and sustainable IoT/IoE solutions.
Monitoring of Cardiorespiratory Parameters during Sleep Using a Special Holder for the Accelerometer Sensor
Authors: Boiko Andrei , Gaiduk Maksym , Scherz Wilhelm Daniel , Gentili Andrea , Conti Massimo , Orcioni Simone , Martínez Madrid Natividad , Seepold Ralf
Published: June 2023

Sleep is extremely important for physical and mental health. Although polysomnography is an established approach in sleep analysis, it is quite intrusive and expensive. Consequently, developing a non-invasive and non-intrusive home sleep monitoring system with minimal influence on patients, that can reliably and accurately measure cardiorespiratory parameters, is of great interest. The aim of this study is to validate a non-invasive and unobtrusive cardiorespiratory parameter monitoring system based on an accelerometer sensor. This system includes a special holder to install the system under the bed mattress. The additional aim is to determine the optimum relative system position (in relation to the subject) at which the most accurate and precise values of measured parameters could be achieved. The data were collected from 23 subjects (13 males and 10 females). The obtained ballistocardiogram signal was sequentially processed using a sixth-order Butterworth bandpass filter and a moving average filter. As a result, an average error (compared to reference values) of 2.24 beats per minute for heart rate and 1.52 breaths per minute for respiratory rate was achieved, regardless of the subject’s sleep position. For males and females, the errors were 2.28 bpm and 2.19 bpm for heart rate and 1.41 rpm and 1.30 rpm for respiratory rate. We determined that placing the sensor and system at chest level is the preferred configuration for cardiorespiratory measurement. Further studies of the system’s performance in larger groups of subjects are required, despite the promising results of the current tests in healthy subjects.
Classification and Recognition of Building Appearance Based on Optimized Gradient-Boosted Decision Tree Algorithm
Authors: Hu Mengting , Guo Lingxiang , Liu Jing , Song Yuxuan
Published: June 2023

There are high concentrations of urban spaces and increasingly complex land use types. Providing an efficient and scientific identification of building types has become a major challenge in urban architectural planning. This study used an optimized gradient-boosted decision tree algorithm to enhance a decision tree model for building classification. Through supervised classification learning, machine learning training was conducted using a business-type weighted database. We innovatively established a form database to store input items. During parameter optimization, parameters such as the number of nodes, maximum depth, and learning rate were gradually adjusted based on the performance of the verification set to achieve optimal performance on the verification set under the same conditions. Simultaneously, a k-fold cross-validation method was used to avoid overfitting. The model clusters trained in the machine learning training corresponded to various city sizes. By setting the parameters to determine the size of the area of land for a target city, the corresponding classification model could be invoked. The experimental results show that this algorithm has high accuracy in building recognition. Especially in R, S, and U-class buildings, the overall accuracy rate of recognition reaches over 94%.
Vision-Based Recognition of Human Motion Intent during Staircase Approaching
Authors: Islam Md Rafi , Haque Md Rejwanul , Imtiaz Masudul H. , Shen Xiangrong , Sazonov Edward
Published: June 2023

Walking in real-world environments involves constant decision-making, e.g., when approaching a staircase, an individual decides whether to engage (climbing the stairs) or avoid. For the control of assistive robots (e.g., robotic lower-limb prostheses), recognizing such motion intent is an important but challenging task, primarily due to the lack of available information. This paper presents a novel vision-based method to recognize an individual’s motion intent when approaching a staircase before the potential transition of motion mode (walking to stair climbing) occurs. Leveraging the egocentric images from a head-mounted camera, the authors trained a YOLOv5 object detection model to detect staircases. Subsequently, an AdaBoost and gradient boost (GB) classifier was developed to recognize the individual’s intention of engaging or avoiding the upcoming stairway. This novel method has been demonstrated to provide reliable (97.69%) recognition at least 2 steps before the potential mode transition, which is expected to provide ample time for the controller mode transition in an assistive robot in real-world use.
Broadband Measurements of Soil Complex Permittivity
Authors: Stellini Justin , Farrugia Lourdes , Farhat Iman , Bonello Julian , Persico Raffaele , Sacco Anthony , Spiteri Kyle , Sammut Charles V.
Published: June 2023

Agriculture is a major consumer of freshwater and is often associated with low water productivity. To prevent drought, farmers tend to over-irrigate, putting a strain on the ever-depleting groundwater resources. To improve modern agricultural techniques and conserve water, quick and accurate estimates of soil water content (SWC) should be made, and irrigation timed correctly in order to optimize crop yield and water use. In this study, soil samples common to the Maltese Islands having different clay, sand, and silt contents were, primarily, investigated to: (a) deduce whether the dielectric constant can be considered as a viable indicator of the SWC for the soils of Malta; (b) determine how soil compaction affects the dielectric constant measurements; and (c) to create calibration curves to directly relate the dielectric constant and the SWC for two different soil types of low and high density. The measurements, which were carried out in the X-band, were facilitated by an experimental setup comprising a two-port Vector Network Analyzer (VNA) connected to a rectangular waveguide system. From data analysis, it was found that for each soil investigated, the dielectric constant increases notably with an increase in both density and SWC. Our findings are expected to aid in future numerical analysis and simulations aimed at developing low-cost, minimally invasive Microwave (MW) systems for localized SWC sensing, and hence, in agricultural water conservation. However, it should be noted that a statistically significant relationship between soil texture and the dielectric constant could not be determined at this stage.
Compact UHF Circularly Polarized Multi-Band Quadrifilar Antenna for CubeSat
Authors: Nguyen Manh Thao , Ferrero Fabien , Trinh Le-Huy
Published: June 2023

This article presents a multi-band right-hand circularly polarized antenna designed for the Cube Satellite (CubeSat). Based on a quadrifilar structure, the antenna provides circular polarization radiation suitable for satellite communication. Moreover, the antenna is designed and fabricated using two 1.6 mm thickness FR4-Epoxy boards connected by metal pins. In order to improve the robustness, a ceramic spacer is placed in the centerboard, and four screws are added at the corners to fix the antenna to the CubeSat structure. These additional parts reduce antenna damage caused by vibrations in the launch vehicle lift-off stage. The proposal has a dimension of 77 × 77 × 10 mm3 and covers the LoRa frequency bands at 868 MHz, 915 MHz, and 923 MHz. According to the measurements in the anechoic chamber, antenna gains with the values of 2.3 dBic and 1.1 dBic are obtained for the 870 MHz and 920 MHz, respectively. Finally, the antenna is integrated into a 3U CubeSat that was launched by a Soyuz launch vehicle in September 2020. The terrestrial-to-space communication link was measured, and the antenna performance was confirmed in a real-life scenario.
Magnetoresistance and Magnetic Relaxation of La-Sr-Mn-O Films Grown on Si/SiO2 Substrate by Pulsed Injection MOCVD
Authors: Žurauskienė Nerija , Rudokas Vakaris , Tolvaišienė Sonata
Published: June 2023

The results of magnetoresistance (MR) and resistance relaxation of nanostructured La1−xSrxMnyO3 (LSMO) films with different film thicknesses (60–480 nm) grown on Si/SiO2 substrate by the pulsed-injection MOCVD technique are presented and compared with the reference manganite LSMO/Al2O3 films of the same thickness. The MR was investigated in permanent (up to 0.7 T) and pulsed (up to 10 T) magnetic fields in the temperature range of 80–300 K, and the resistance-relaxation processes were studied after the switch-off of the magnetic pulse with an amplitude of 10 T and a duration of 200 μs. It was found that the high-field MR values were comparable for all investigated films (~−40% at 10 T), whereas the memory effects differed depending on the film thickness and substrate used for the deposition. It was demonstrated that resistance relaxation to the initial state after removal of the magnetic field occurred in two time scales: fast’ (~300 μs) and slow (longer than 10 ms). The observed fast relaxation process was analyzed using the Kolmogorov–Avrami–Fatuzzo model, taking into account the reorientation of magnetic domains into their equilibrium state. The smallest remnant resistivity values were found for the LSMO films grown on SiO2/Si substrate in comparison to the LSMO/Al2O3 films. The testing of the LSMO/SiO2/Si-based magnetic sensors in an alternating magnetic field with a half-period of 22 μs demonstrated that these films could be used for the development of fast magnetic sensors operating at room temperature. For operation at cryogenic temperature, the LSMO/SiO2/Si films could be employed only for single-pulse measurements due to magnetic-memory effects.
Review of Power Control Methods for a Variable Average Power Load Model Designed for a Microgrid with Non-Controllable Renewable Energy Sources
Authors: Zelba Mantas , Deveikis Tomas , Gudžius Saulius , Jonaitis Audrius , Bandza Almantas
Published: June 2023

Microgrid systems may employ various combinations of system designs to connect generating units, and the number of different system designs increases exponentially upon adding different brands of inverters to a system. Each of the different microgrid system designs must be set up in a way that it works in balance. An example of an unbalanced microgrid system is given in this paper, with the main issue being the non-predictive excess power, which causes a frequency rise and faulty conditions in the microgrid system. There are many simple options for controlling excess power in a microgrid system; however, none of these options solve the issue permanently while ensuring excess power control without affecting the system’s accumulated energy—the battery state-of-charge (SOC) level. Therefore, there is a need to create a variable average power load (VAPL) device to utilize the excess power at a rate it is changing to avoid a reduction in accumulated energy. The main goal of this study is to review average power control methods for the VAPL device and provide guidance to researchers in selecting the most suitable method for controlling excess power. A key finding of the paper is a suggested optimal average power control method ensuring that the VAPL device is versatile to implement, economically attractive, and not harmful to other devices in a microgrid system.
Factors Affecting Water Quality and Sustainability in Dental Practices in Greece
Authors: Antoniadou Maria , Intzes Anestis , Kladouchas Christos , Christou Iliana , Chatzigeorgiou Stavroula , Plexida Martha , Stefanidakis Valantis , Tzoutzas Ioannis
Published: June 2023

Good water quality, achieved with environmentally friendly means, is essential in ensuring the safe operation of a dental practice. Our aim was to evaluate procedures and protocols used by dentists for water quality and sustainability. Greek dentists (n = 206) participated in this questionnaire-based study. Statistically significant results (p < 0.05) have shown that (a) female dentists were more interested in additional information about water quality (87.5% vs. 71.8%), had water supply directly from the public network to the dental unit (68.8% vs. 73.8%), were more likely to disinfect surfaces between two appointments (97.7% vs. 88.0%) and were more likely to perform annual maintenance to the dental unit (66.3% vs. 57.9%). (b) More experienced dentists were also more likely to clean the waterline network of the unit with a large amount of fluid once a day (39.3–48.3%), had newer equipment, had more handpieces, and spent more time cleaning and disinfecting the unit (χ2 = 26.21). (c) Dentists who have studied abroad were more likely to perform less strict antiseptic protocols while believing that their practices are environmentally friendly (χ2 = 10.93). Dentists with some postgraduate education were more likely to have an assistant, know the active substance of the antiseptic, supply antiseptic to the handpieces automatically and maintain the dental unit annually (χ2 = 7.24). (d) Dentists who practiced general dentistry were less likely to have an assistant and performed less strict protocols while they cleaned suctions with a large amount of fluid less often (χ2 = 11.64). Dentists who practiced in a clinic (with employees) were more likely to have newer equipment, have an assistant and perform stricter water sustainability protocols. (e) Dentists with a higher annual income were also more likely to have an assistant, perform microbiological tests for the quality of the water of the unit, have a continuous water supply system and perform stricter protocols for water quality of the unit. Overall, less experienced (and younger) dentists are more informed about water quality legislation (27.6%) compared to more experienced and older dentists (13.2–17.5%). Gender, work experience, level of education and dental office characteristics are important factors determining water sustainability, waterlines, and equipment maintenance in dental practice. Dental associations should raise awareness regarding water quality and sustainability, investing in lifelong learning, while implementing protocols and green strategies.
Sustainable Apparel Consumption: Personal Norms, CSR Expectations, and Hedonic vs. Utilitarian Shopping Value
Authors: Lin Carolyn A. , Wang Xihui , Yang Yukyung
Published: June 2023

The sustainable consumption trend is gaining popularity among Gen Z. Guided by the environmental awareness construct, Norm Activation Model, corporate social responsibility paradigm, and shopping value perspective, this study aims to assess how environmental awareness is connected to consumer evaluations of their personal consumption behavior and corporate social responsibility to help explain their sustainable apparel purchase intention, in conjunction with consumer shopping motivation. An online survey was conducted with a group of Gen Z consumers (N = 192). The results from testing the conceptual model indicated that environmental awareness was positively linked to personal norms and CSR expectations, both of which were similarly related to green purchase intentions. While hedonic and utilitarian shopping value was positively associated with CSR expectations, they were both negative predictors of green purchase intentions. This study is the first to integrate environmental ethics, personal ethics, expectations of corporate ethics, and hedonic vs. utilitarian consumption value to better understand the attitude–behavior gap in sustainable apparel purchase decision-making.
Navigating Turbulent Environments: Exploring Resilience in SMEs through Complex Adaptive Systems Perspective
Authors: Yapicioglu Balkiz
Published: June 2023

This study seeks to explore how owner–managers of small and medium-sized enterprises navigate a constantly changing and turbulent environment following a traumatic experience and how they build resilience in their organizations by drawing upon memories through a complex adaptive system lens. Specifically, this study investigates the major factors shaping the management strategies of SMEs operating in the infrastructure construction sector in North Cyprus, where foreign aid/the patron country is the primary source of financing and therefore the major driver of strategies. To gather primary data, semistructured interviews were conducted with owner–managers of grade 1 construction SMEs, who can participate in internationally financed public projects. A qualitative approach using thematic analysis was adopted, and findings indicate that the most influential factor shaping the management strategies of SMEs in North Cyprus is the macro characteristics of the sociopolitical environment. These characteristics evoke memories for owner–managers and lead to a dissipative approach towards managing their SMEs, creating resilience in the face of North Cyprus’ ever-changing political environment.
A Creative Approach for the Architectural Technology: Using the ExtrArtis Model to Regenerate the Built Environment
Authors: Ciampa Francesca
Published: June 2023

In the context of cultural heritage reuse, creative businesses can play the role of activators of sustainable transition processes in the built environment. The exercise of the functions by creative enterprises can improve actions of regeneration of local identity, values, and built heritage. The aim is to demonstrate that creative enterprises are strategic industries able to activate actions of custody and cultural heritage valorization, proposing themselves on the territory as culture-led regeneration tools. The methodology discusses integrated strategies that intervene in the systemic criticalities of cities to regenerate tangible and intangible cultural heritage through multidimensional, multi-actor, and multicriteria approaches, matching community and the built environment. The result concerns the identification of a system of actor issues and creative criteria using the ExtrArtis© model, a transformative driver that constitutes a creative class as the guardian of the genius loci.
Multivariate Grey Prediction Model Application in Civil Aviation Carbon Emission Based on Fractional Order Accumulation and Background Value Optimization
Authors: Li Cheng , Li Yangzhou , Xing Jian
Published: June 2023

The GM(1,N) model, as a classical multivariate grey prediction model, can make a holistic and dynamic analysis of multiple factors and reflect the dynamic change relationship between the variable series and the related factor series. However, numerous works in the literature show that the GM(1,N) model has mechanistic defects, parametric defects, and structural defects. Therefore, the thesis establishes the OGM(1,N) model based on the GM(1,N) model by adding the linear correction term and the amount of grey action. According to the principle of dynamic optimization, the PSO algorithm is used to determine the background value. On this basis, the fractional order idea is introduced to push the model order from the integer field to the real field, and the FOBGM(1,N) model is established to systematically reduce the model error. Second, the literature in the ScienceDirect database for the last ten years is reviewed, and the carbon emission impact factors of civil aviation are selected. The calculated carbon emission values are taken as sample data based on Method 2 of Civil Aviation in Volume 2 of the 2006 IPCC Guide to National Greenhouse Gas Inventories. The results show that the prediction accuracy of the model has an increasing trend after multi-layer and multi-angle optimization. Among them, the MAPE of the OGM model and FOBGM model decreased by 24.40% and 31.86% compared with the GM(1,N) model. The 5-year average prediction accuracy of the FOBGM model reaches 99.996%, which verifies the effectiveness and practicality of the model improvement and has certain practical significance and application prospects.
Optimization of Simultaneous Pickup and Delivery Vehicle Routing with Three-Dimensional Balanced Loading Constraints
Authors: Zhang Yinggui , Sheng Lining
Published: June 2023

In order to promote the cost reduction and efficiency improvement of the logistics distribution process and to guarantee the safety of goods transportation, this paper studies the portfolio optimization of goods loading and the problem of simultaneous pickup and delivery vehicle routing. A balanced loading constraint was introduced to restrict loading through two aspects of axle weight bearing and lateral center-of-gravity offset. With the shortest total route length as the objective, this paper constructs a simultaneous pickup and delivery vehicle routing model with three-dimensional (3D) balanced loading constraints (3BL-VRPSPD). Additionally, a hybrid tabu search (TS) algorithm embedded loading test was proposed to solve this problem. Firstly, a heuristic insertion method was applied to determine the initial routing scheme, and the node swapping and relocation operators were designed to construct the tabu neighborhood scheme for routing optimization. On this basis, the 3D balanced loading was incorporated into the routing iteration process. A balanced loading algorithm, combining multiple-indicator ordering and maximum space division strategies (MOMD), was formulated to develop a 3D-balanced loading plan for goods with a pickup and delivery vehicle routing scheme. Finally, standard instances verified the effectiveness of the method. The results show that the proposed method can effectively optimize 3BL-VRPSPD and outperform other algorithms.
The Multi-Scale Model Method for U-Ribs Temperature-Induced Stress Analysis in Long-Span Cable-Stayed Bridges through Monitoring Data
Authors: Zhu Fengqi , Yu Yinquan , Li Panjie , Zhang Jian
Published: June 2023

Temperature is one of the important factors that affect the fatigue failure of the welds in orthotropic steel desks (OSD) between U-ribs and bridge decks. In this study, a new analysis method for temperature-induced stress in U-ribs is proposed based on multi-scale finite element (FE) models and monitoring data First, the long-term temperature data of a long-span cable-stayed bridge is processed. This research reveals that a vertical temperature gradient is observed rather than a transverse temperature gradient on the long-span steel box girder bridge with tuyere components. There is a linear relationship between temperature and temperature-induced displacement, taking into account the time delay effect (approximately one hour). Then, a multi-scale FE model is established using the substructure method to condense each segment of the steel girder into a super-element, and the overall bridge temperature-induced displacement and temperature-induced stress of the local U-rib on the OSD are analyzed. The agreement between the calculated temperature-induced stresses and measured values demonstrates the effectiveness of the multi-scale modeling strategy. This approach provides a valuable reference for the evaluation and management of bridge safety. Finally, based on the multi-scale FE model, the temperature-induced strain distribution of components on the OSD is studied. This research reveals that the deflection of the girder continually changes with the temperature variation, and the temperature-induced strain of the girder exhibits a variation range of approximately 100 με.
The Effect of Land Tenure Institutional Factors on Small Landholders’ Sustainable Land Management Investment: Evidence from the Highlands of Ethiopia
Authors: Abab Shewakena Aytenfisu , Senbeta Feyera , Negash Tamirat Tefera
Published: June 2023

Sustainable Land Management (SLM) is one of the key policy responses being implemented to curb land degradation in the highlands of Ethiopia. However, there is scant evidence to what extent Land Tenure Institutional Factors (LTIFs) influence small landholders’ on-farm investment in SLM. The overall objective of this study is, therefore, to understand the extent to which LTIFs influence on-farm SLM investment in the highlands of Ethiopia through unbundling tenure security (de jure, de facto, and perceived) across a bundle of rights. Survey data were collected between April and May 2021 from 2296 smallholder households and 6692 parcels of 19 highland woredas (districts) in three regional states (Amhara, Oromia, and SNNP) in Ethiopia. A probit regression model was used to estimate the average marginal effects of LTIFs quantitatively and supported by an in-depth qualitative analysis. The results revealed that 10 out of 16 LTIF-related variables have significantly influenced households’ on-farm investment in SLM with average marginal effect ranging from a minimum of 3% (tree tenure security risks) to a maximum of 14% (possession of land certificates), at 95% confidence interval, compared to a mean probability of 45%. The results also revealed that some of the households’ socio-economic and demographic factors and parcel-specific variables have significantly influenced on-farm SLM investment. These imply two policy issues. Firstly, it strengthens the notion that security of tenure may be a necessary condition, but not a sufficient, factor to incentivize smallholders’ on-farm SLM investment. Secondly, an in-depth analysis of the security of tenure categories across a bundle of rights is necessary to help formulate context-specific SLM policy and strategy incentivizing smallholders’ on-farm SLM investment.
Numerical Approach for Solving a Fractional-Order Norovirus Epidemic Model with Vaccination and Asymptomatic Carriers
Authors: Raezah Aeshah A. , Zarin Rahat , Raizah Zehba
Published: June 2023

This paper explored the impact of population symmetry on the spread and control of a norovirus epidemic. The study proposed a mathematical model for the norovirus epidemic that takes into account asymptomatic infected individuals and vaccination effects using a non-singular fractional operator of Atanganaa–Baleanu Caputo (ABC). Fixed point theory, specifically Schauder and Banach’s fixed point theory, was used to investigate the existence and uniqueness of solutions for the proposed model. The study employed MATLAB software to generate simulation results and demonstrate the effectiveness of the fractional order q. A general numerical algorithm based on Adams–Bashforth and Newton’s Polynomial method was developed to approximate the solution. Furthermore, the stability of the proposed model was analyzed using Ulam–Hyers stability techniques. The basic reproductive number was calculated with the help of next-generation matrix techniques. The sensitivity analysis of the model parameters was performed to test which parameter is the most sensitive for the epidemic. The values of the parameters were estimated with the help of least square curve fitting tools. The results of the study provide valuable insights into the behavior of the proposed model and demonstrate the potential applications of fractional calculus in solving complex problems related to disease transmission.
Same but Different? Comparing the Epidemiology, Treatments and Outcomes of COVID-19 and Non-COVID-19 ARDS Cases in Germany Using a Sample of Claims Data from 2021 and 2019
Authors: Bernauer Eva , Alebrand Felix , Heurich Manuel
Published: June 2023

Background: Acute respiratory distress syndrome (ARDS) is a severe lung condition that can be caused by a variety of underlying illnesses. Due to SARS-CoV-2, the number of cases with ARDS has increased worldwide, making it essential to compare this form of acute respiratory failure with classical causes of ARDS. While there have been several studies investigating the differences between COVID-19 and non-COVID-19 ARDS in early stages of the pandemic, little is known about the differences in later phases, especially in Germany. Aim: The aim of this study is to characterize and compare the comorbidities, treatments, adverse events, and outcomes of COVID-19-associated ARDS and non-COVID-19 ARDS using a representative sample of German health claims data from the years 2019 and 2021. Methods: We compare percentages and median values of the quantities of interest from the COVID-19 and non-COVID-19 ARDS group, with p-values calculated after conducting Pearson’s chi-squared test or the Wilcoxon rank sum test. We also run logistic regressions to access the effect of comorbidities on mortality for COVID-19 ARDS and non-COVID-19 ARDS. Results: Despite many similarities, we find that that there are some remarkable differences between COVID-19 and non-COVID-19 ARDS cases in Germany. Most importantly, COVID-19 ARDS cases display fewer comorbidities and adverse events, and are more often treated with non-invasive ventilation and nasal high-flow therapy. Conclusions: This study highlights the importance of comprehending the contrasting epidemiological features and clinical outcomes of COVID-19 and non-COVID-19 ARDS. This understanding can aid in clinical decision making and guide future research initiatives aimed at enhancing the management of patients afflicted with this severe condition.
Post-COVID-19 Syndrome in Non-Hospitalized Individuals: Healthcare Situation 2 Years after SARS-CoV-2 Infection
Authors: Kirchberger Inge , Meisinger Christine , Warm Tobias D. , Hyhlik-Dürr Alexander , Linseisen Jakob , Goßlau Yvonne
Published: June 2023

Although “post-COVID-19 syndrome” (PCS) is reported to be common even in non-hospitalized individuals, long-term information on symptom burden, healthcare needs, utilization, and satisfaction with healthcare is scarce. The objectives of this study were to describe symptom burden, healthcare utilization and experiences with the healthcare offered for PCS in a German sample of non-hospitalized persons 2 years after SARS-CoV-2 infection. Individuals with past COVID-19 confirmed by positive polymerase chain reaction testing were examined at the University Hospital of Augsburg from 4 November 2020 to 26 May 2021 and completed a postal questionnaire between 14 June 2022 and 1 November 2022. Participants who self-reported the presence of fatigue, dyspnea on exertion, memory problems or concentration problems were classified as having PCS. Of the 304 non-hospitalized participants (58.2% female, median age 53.5), 210 (69.1%) had a PCS. Among these, 18.8% had slight to moderate functional limitations. Participants with PCS showed a significantly higher utilization of healthcare and a large proportion complained about lacking information on persistent COVID-19 symptoms and problems finding competent healthcare providers. The results indicate the need to optimize patient information on PCS, facilitate access to specialized healthcare providers, provide treatment options in the primary care setting and improve the education of healthcare providers.
Investigating Seawater Intrusion in Republic of South Africa’s Heuningnes, Cape Agulhas Using Hydrogeochemistry and Seawater Fraction Techniques
Authors: Xaza Abongile , Mapoma Harold Wilson Tumwitike , Abiye Tamiru A. , Clarke Sumaya , Kanyerere Thokozani
Published: June 2023

The Heuningnes Catchment in the Republic of South Africa was used as a case study in this research to describe the application of saltwater fraction/quantification and hydrogeochemistry methods to evaluate the extent of saline intrusion in the coastal aquifers. The argument of the research is that the presence of seawater incursion may be conclusively determined by combining the examination of the major ions, seawater fraction, stable isotopes of water, bromide, and geochemical modeling. Using stable isotopes of oxygen (18O) and deuterium (2H), major ions chemistry, seawater composition, and geochemical modeling, the genesis of salinity and mixing of different water masses were examined. Twenty-nine (29) samples of groundwater were examined. All samples showed water facies of the Na-Cl type, indicating a seawater-related origin. The significance of mixing in coastal aquifers under natural conditions was shown by the hydrogeochemical characteristics of key ions derived from ionic ratios, which demonstrated substantial adherence to mixing lines among endmembers for freshwater as well as saltwater (seawater). The quantification of seawater contribution in groundwater percentages varied from 0.01 to 43%, with three samples having concentrations of seawater above 50%. It was clear from the hydrogeochemical analysis and determination of the proportion of saltwater that the seawater intrusion impacted the coastal fresh groundwater. In addition, the chloride concentration in the groundwater ranged from 81.5 to 26,557.5 mg/L, with the corresponding δ18O values ranging from −5.5‰ to −0.9‰, which suggested that freshwater and saltwater were mixing. The Br−/Cl− ratios showed that evaporation had played a part in elevating groundwater salinity as well. Since saturation indices were below zero, the mineral dissolution could also contribute to the salinization of groundwater. Further proof of seawater incursion in the investigated catchment was supplied by geochemical modeling and bromide. Even though such tools were not verified in multiple coastal aquifers for widespread generalization, the study offered a scientifically significant understanding of the application of such tools on seawater intrusion in coastal aquifers and has useful recommendations for the aquifer setting of similar environments.
Algae and Hydrophytes as Potential Plants for Bioremediation of Heavy Metals from Industrial Wastewater
Authors: Farid Naila , Ullah Amin , Khan Sara , Butt Sadia , Khan Amir Zeb , Afsheen Zobia , El-Serehy Hamed A. , Yasmin Humaira , Ayaz Tehreem , Ali Qurban
Published: June 2023

Aquatic bodies contaminated by heavy metals (HMs) are one of the leading issues due to rapidly growing industries. The remediation of using algae and hydrophytes acts as an environmentally friendly and cost effective. This study was performed to investigate the pollution load, especially HMs, in the wastewater of the Gadoon Industrial Estate and to utilize the hydrophytes (Typha latifolia (TL) and Eicchornia crassipes (EI)) and algae (Zygnema pectiantum (ZP) and Spyrogyra species (SS)) as bioremediators. The wastewater was obtained and assessed for physiochemical parameters before treating with the selected species. The pot experiment was performed for 40 days. Then the wastewater samples and selected species were obtained from each pot to analyze the metal removal efficiency and assess for metal concentrations using atomic absorption spectrophotometry. The dissolved oxygen (DO; 114 mg/L), total suspended solids (TSS; 89.30 mg/L), electrical conductivity (EC; 6.35 mS/cm), chemical oxygen demand (COD) (236 mg/L), biological oxygen demand (BOD; 143 mg/L), and total dissolved solids (TDS; 559.67 mg/L), pH (6.85) were analyzed. The HMs were noted as Zn (5.73 mg/L) and Cu (7.13 mg/L). The wastewater was then treated with the species, and significant reductions were detected in physicochemical characteristics of the wastewater such as DO (13.15–62.20%), TSS (9.18–67.99%), EC (74.01–91.18%), COD (25.84–73.30%), BOD (21.67–73.42%), and TDS (14.02–95.93%). The hydrophytes and algae removed up to 82.19% of the Zn and 85.13% of the Cu from the wastewater. The study revealed that the hydrophytes and algae significantly decreased the HM levels in the wastewater (p ≤ 0.05). The study found TL, EI, ZP, and SS as the best hyper accumulative species for Zn and Cu removal from wastewater. The HMs were removed in the order of Cu > Zn. The most efficient removal for Cu was found by Typha latifolia and Zn by Zygnema pectiantum. It was concluded that bioremediation is an environmentally friendly and cost-effective technique that can be used for the treatment of wastewater due to the efficiency of algae and hydrophytes species in terms of HM removal.
Preliminary Study of Cesium Immobilization in a Geopolymer Matrix
Authors: Kocsis Erika , Fehérvári Máté , Novák Máté , Tóth-Bodrogi Edit , Kovács Tibor
Published: June 2023

Geopolymers are modern synthetic materials that have many beneficial characteristics, e.g. excellent mechanical properties, fire- and heat-resistance, minimal shrinkage and can be molded into shape. Given their aforementioned characteristics, geopolymers could be applicable as conditioning materials, e.g. to handle hazardous waste and radioactive materials. However, their long-term applicability needs to be investigated.The aim of this study is to investigate the mobility of Cs-137 radionuclides in embedding materials. Different geopolymeric matrices - namely kaolinite, bentonite, zeolites and red mud - were tested. The leach test was performed according to the ASTM C1308-08(2017) standard and the activity concentration of Cs-137 isotopes was measured by gamma spectrometry using a high-purity germanium (HPGe) semiconductor detector. According to our preliminary results, the matrices that resulted in the most significant immobilization effect were those in which bentonite, cement, fly ash and 8M NaOH were used, releasing approximately 10% of the cesium.
Annealing Effect on Copper-Doped Sodium Borate Glasses (Na2O.4B2O3)
Authors: Aboutaleb Djamila , Safi Brahim
Published: June 2023

The annealing effect of an alkali borate type glass below its softening point was investigated according to the Na2O-B2O3 binary system. The samples were doped by introducing different amounts of copper oxide (CuO). The properties of elaborate glasses before and after annealing were studied. X-ray diffraction (XRD) as well as optical and infrared spectroscopy were used in this study. The results obtained show that annealing, that is, a heat treatment process, affects the structure of this type of glass by redistributing its structural units and partially correcting any defects, thereby reinforcing the structure. It was noticed that the BO3 units were reformed while the number of BO4 ones decreased, leading to an increase in the coefficient of thermal expansion, a decrease in both the refractive index and optical dispersion, the weakening of mechanical properties as well as a reduction in thermal conductivity and electric permittivity.
Agotamiento del modelo neoliberal en Ecuador: la caída de Guillermo Lasso
Authors: García-Mayoral Álvaro
Published: June 2023

Desde el año 2017 se ha llevado a cabo un proceso de aplicación de una agenda marcadamente neoliberal en Ecuador. Las necesidades de reducción del déficit fiscal y la deuda pública llevaron al gobierno de Lenín Moreno a aplicar medidas de ajuste y a aceptar las condiciones impuestas por financiadores como el FMI. Estas políticas llevaron a la ciudadanía ecuatoriana a una situación de vulnerabilidad extrema agravada por fenómenos como la pandemia de COVID-19 o la guerra en Ucrania. En ese marco, el gobierno liberal conservador de Guillermo Lasso tampoco ha sido capaz de hacer frente a los desafíos económicos y políticos del país y, decretando la “muerte cruzada”, convocó a la sociedad ecuatoriana a unas elecciones que pueden dar por concluido este ciclo neoliberal en Ecuador.
Effect of Atorvastatin and Lactobacillus acidophilus on cholesterol metabolism in experimental hypercholesterolemia
Authors: Çiftci Gülay , Çiftci Alper , Çenesiz Metin , Onuk Burcu , Çenesiz Sena , Gülhan Timur
Published: June 2023

Hypercholesterolemia is a very common health problem in the world. In this study, it was aimed to investigate the effects of atorvastatin and Lactobacillus acidophilus probiotic on cholesterol metabolism, and formation of neurosterides and myelin. Five groups were formed in the study. Group-1 was fed with standard rat chow as a control group. Group-2 was designated as hypercholosterolemi group and fed with cholesterol added rat chow. Group-3 was fed with cholesterol and atorvastatin. L.acidophilus probiotic was given in the last four weeks of the experiment to Group-4. L.acidophilus and atorvastatin were given together for the last four weeks to the Group-5. At the end of the trial, some biochemical parameters were determined by autoanalyzer device and ELISA. LDL receptor (LDL-R), HMG-CoA reductase, GAPDH genes were determined by RT-PCR. In the case of adding cholesterol to the diet, total cholesterol in the serum, LDL-cholesterol level increased, HDL-cholesterol level decreased, liver enzyme activity increased, Ox-LDL level increased significantly in the brain, testosterone, progesterone, MBP level, nNOS activity were significantly increased. GAPDH gene gave bands at the same intensities in brain and liver of in all groups. When compared with GAPDH, band intensities of the LDL-R and HMG-CoA reductase genes were decreased. It was determined that the hypocholesteric effect of the combination of statin and probiotic is better and neurosterides have a positive contribution to the level of serotonin hormone. As a result, it was concluded that L. acidophilus probiotic supplementation with atorvastatin can be recommended as supportive product in the treatment of hypercholesterolemia.
Afectación cardiaca por Síndrome Inflamatorio Multisistémico asociado A SARS-CoV-2 en pacientes pediátricos
Authors: Barrera Castro María Esther , Flores Montesinos Carlos Enrique , Barrera Castro Alberto Rogelio
Published: June 2023

Estudios recientes han planteado que el curso clínico puede ser crítico en niños debido a la naturaleza multifacética de la enfermedad. El Síndrome inflamatorio multisistémico asociado a SARS-CoV-2 (MIS-C), cursa con daño multisistémico, con predominio de afectación cardíaca que compromete la vida del paciente pediátrico. Objetivo. Identificar las principales alteraciones cardíacas por Síndrome inflamatorio multisistémico asociado a SARS-CoV-2 en pacientes pediátricos. Metodología. Se realizó una revisión sistemática mediante una búsqueda informativa en bases de datos. Se incluyeron estudios recientes publicados desde el año 2019 hasta el año 2022 que informaron acerca de las manifestaciones por afectación cardíaca, tratamiento en pacientes con alteración cardíaca por MIS-C y factores de riesgo asociados a MIS-C grave. Conclusiones. Las principales alteraciones cardiacas por síndrome inflamatorio multisistémico asociado a SARS-CoV-2 en pacientes pediátricos mostraron que las patologías más comunes fueron shock, arritmias cardíacas, derrame pericárdico, dilatación de las arterias coronarias y miocarditis aguda, por ende, las comorbilidades cardíacas son muy frecuentes en niños con MIS-C, donde, la  afectación cardíaca y sistémica juega un papel muy importantes en el desarrollo de disfunción ventricular, miocarditis, anomalías de las arterias coronarias, arritmias y alteraciones del ritmo consideradas entres las más comunes.
Performance Analysis of Village Apparatus in Village Government at Sugiharjo Village, District Batang Kuis, Deli Serdang Regency
Authors: Watri Nidi , Hartono Budi , Adam Adam
Published: June 2023

This research is focuses on the performance of village apparatus in administering village government at Sugiharjo Village, District Batang Kuis, Deli Serdang Regency. By analysing the performance of village apparatus in accordance with the performance analysis indicators of Mangkunegara (2019) and the inhibiting factors for village apparatus performance, so that village apparatus can work optimally in carrying out their duties and support the implementation of village government and carrying out government affairs, also in community interests in accordance with the mandate of Law Number 6 of 2014 concerning Villages. This study uses a descriptive method with a qualitative approach, conducting direct interviews with Sugiharjo Village officials and the people in that village. Based on research and analysis of performance indicators: quality of work, quantity of work, discipline, initiative, and responsibility, the performance of the Sugiharjo Village Apparatus in carrying out their duties is considered not optimal, especially when there are still violations of work discipline, the violations related to working hours. Some factors inhibiting the performance of village apparatus in the form of a lack of number of village apparatus and a lack of development quality of human resources in Sugiharjo Village Apparatuses. It is necessary to make efforts to develop human resources for Sugiharjo Village Apparatuses to improve technical, theoretical and work discipline capabilities to improve apparatus performance Sugiharjo village.