Journal Articles, Multidisciplinary Digital Publishing Institute (MDPI)

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  • Performance Evaluation of Numerical Weather Prediction Models in Forecasting Rainfall Events in Kerala, India
    Nitha, V.; Pramada, S. K.; Praseed, N. S.; Sridhar, Venkataramana (MDPI, 2025-03-25)
    Heavy rainfall events are the main cause of flooding, especially in regions like Kerala, India. Kerala is vulnerable to extreme weather due to its geographical location in the Western Ghats. Accurate forecasting of rainfall events is essential for minimizing the impact of floods on life, infrastructure, and agriculture. For accurate forecasting of heavy rainfall events in this region, region-specific evaluations of NWP model performance are very important. This study evaluated the performance of six Numerical Weather Prediction (NWP) models—NCEP, NCMRWF, ECMWF, CMA, UKMO, and JMA—in forecasting heavy rainfall events in Kerala. A comprehensive assessment of these models was performed using traditional performance metrics, categorical precipitation metrics, and Fractional Skill Scores (FSSs) across different forecast lead times. FSSs were calculated for different rainfall thresholds (100 mm, 50 mm, 5 mm). The results reveal that all models captured rainfall patterns well for the lower threshold of 5 mm, but most of the models struggled to accurately forecast heavy rainfall, especially for longer lead times. JMA performed well overall in most of the metrics except False Alarm Ratio (FAR). It showed high FAR, which revealed that it may predict false rainfall events. ECMWF demonstrated consistent performance. NCEP and UKMO performed moderately well. CMA, and NCMRWF had the lowest accuracy either due to more errors or biases. The findings underscore the trade-offs in model performance, suggesting that model selection should depend on the accuracy required or rainfall event prediction capability. This study recommends the use of Multi-Model Ensembles (MME) to improve forecasting accuracy, integrate the strengths of the best-performing models, and reduce biases. Future research can also focus on expanding observational networks and employing advanced data assimilation techniques for more reliable predictions, particularly in regions with complex terrain such as Kerala.
  • A Quantum Key Distribution Routing Scheme for a Zero-Trust QKD Network System: A Moving Target Defense Approach
    Ghourab, Esraa M.; Azab, Mohamed; Gračanin, Denis (MDPI, 2025-03-26)
    Quantum key distribution (QKD), a key application of quantum information technology and “one-time pad” (OTP) encryption, enables secure key exchange with information-theoretic security, meaning its security is grounded in the laws of physics rather than computational assumptions. However, in QKD networks, achieving long-distance communication often requires trusted relays to mitigate channel losses. This reliance introduces significant challenges, including vulnerabilities to compromised relays and the high costs of infrastructure, which hinder widespread deployment. To address these limitations, we propose a zero-trust spatiotemporal diversification framework for multipath–multi-key distribution. The proposed approach enhances the security of end-to-end key distribution by dynamically shuffling key exchange routes, enabling secure multipath key distribution. Furthermore, it incorporates a dynamic adaptive path recovery mechanism that leverages a recursive penalty model to identify and exclude suspicious or compromised relay nodes. To validate this framework, we conducted extensive simulations and compared its performance against established multipath QKD methods. The results demonstrate that the proposed approach achieves a 97.22% lower attack success rate with 20% attacker pervasiveness and a 91.42% reduction in the attack success rate for single key transmission. The total security percentage improves by 35% under 20% attacker pervasiveness, and security enhancement reaches 79.6% when increasing QKD pairs. Additionally, the proposed scheme exhibits an 86.04% improvement in defense against interception and nearly doubles the key distribution success rate compared to traditional methods. The results demonstrate that the proposed approach significantly improves both security robustness and efficiency, underscoring its potential to advance the practical deployment of QKD networks.
  • Reconsidering the Social in Language Learning: A State of the Science and an Agenda for Future Research in Variationist SLA
    Gudmestad, Aarnes; Kanwit, Matthew (MDPI, 2025-03-28)
    The current paper offers a critical reflection on the role of the social dimension of the second language (L2) development of sociolinguistic competence. We center our discussion of L2 sociolinguistic competence on variationist approaches to second language acquisition (SLA) and the study of variable structures. We first introduce the framework of variationist SLA and offer a brief overview of some of the social, and more broadly extralinguistic, factors that have been investigated in this line of inquiry. We then discuss the three waves of variationist sociolinguistics and various social factors that have been examined in other socially oriented approaches to SLA. By reflecting on these bodies of research, our goal is to identify how the insights from this work (i.e., research couched in the second and third waves of variationist sociolinguistics and in other socially oriented approaches to SLA) could be extended to the study of L2 sociolinguistic competence. We argue that greater attention to the social nature of language in variationist SLA is needed in order to more fully understand the L2 development of variable structures.
  • SYNGAP1 Syndrome and the Brain Gene Registry
    Greco, Melissa R.; Chatterjee, Maya; Taylor, Alexa M.; Gropman, Andrea L. (MDPI, 2025-03-30)
    Background: The human brain relies on complex synaptic communication regulated by key genes such as SYNGAP1. SYNGAP1 encodes the GTPase-Activating Protein (SYNGAP), a critical synaptic plasticity and neuronal excitability regulator. Impaired SYNGAP1 function leads to neurodevelopmental disorders (NDDs) characterized by intellectual disability (ID), epilepsy, and behavioral abnormalities. These variants disrupt Ras signaling, altering AMPA receptor transport and synaptic plasticity and contributing to cognitive and motor difficulties. Despite advancements, challenges remain in defining genotype–phenotype correlations and distinguishing SYNGAP1-related disorders from other NDDs, which could improve underdiagnosis and misdiagnosis. Brain Gene Registry: The Brain Gene Registry (BGR) was established as a collaborative initiative, consolidating genomic and phenotypic data across multiple research centers. This database allows for extensive analyses, facilitating improved diagnostic accuracy, earlier interventions, and targeted therapeutic strategies. The BGR enhances our understanding of rare genetic conditions and is critical for advancing research on SYNGAP1-related disorders. Conclusions: While no FDA-approved treatments exist for SYNGAP1-related disorders, several therapeutic approaches are being investigated. These include taurine supplementation, ketogenic diets, and molecular strategies such as antisense oligonucleotide therapy to restore SYNGAP1 expression. Behavioral and rehabilitative interventions remain key for managing developmental and cognitive symptoms. Advancing research through initiatives like the BGR is crucial for refining genotype–phenotype associations and developing precision medicine approaches. A comprehensive understanding of SYNGAP1-related disorders will improve clinical outcomes and patient care, underscoring the need for continued interdisciplinary collaboration in neurodevelopmental genetics.
  • Evaluation of Flange Grease on Revenue Service Tracks Using Laser-Based Systems and Machine Learning
    Rahalkar, Aditya; Mirzaei, S. Morteza; Chen, Yang; Holton, Carvel; Ahmadian, Mehdi (MDPI, 2025-03-31)
    This study presents a machine learning approach for estimating the presence and extent of flange-face lubrication on a rail. It offers an alternative to the current empirical and subjective methods for lubrication assessment, in which track engineers’ periodic visual inspections are used to evaluate the condition of the rail. This alternative approach uses a laser-based optical sensing system developed by the Railway Technologies Laboratory (RTL) located at Virginia Tech in Blacksburg, VA, combined with a machine learning calibration model. The optical sensing system can capture the fluorescence emitted by the grease to identify its presence, while the machine learning model classifies the extent of grease present into four thickness indices (TIs), from 0 to 3, representing heavy (3), medium (2), light (1) and low/no (0) lubrication. Both laboratory and field tests are conducted, with the results demonstrating the ability of the system to differentiate lubrication levels and measure the presence or absence of grease and TI with an accuracy of 90%.
  • Detecting Credit-Seeking Behavior with Programmed Instruction Framesets in a Formal Languages Course
    Elnady, Yusuf; Farghally, Mohammed; Mohammed, Mostafa; Shaffer, Clifford A. (MDPI, 2025-03-31)
    When students use an online eTextbook with content and interactive graded exercises, they often display aspects of two types of behavior: credit-seeking and knowledge-seeking. A student might behave to some degree in either or both ways with given content. In this work, we attempt to detect the degree to which either behavior takes place and investigate relationships with student performance. Our testbed is an eTextbook for teaching Formal Languages, an advanced Computer Science course. This eTextbook uses Programmed Instruction framesets (slideshows with frequent questions interspersed to keep students engaged) to deliver a significant portion of the material. We analyze session interactions to detect credit-seeking incidents in two ways. We start with an unsupervised machine learning model that clusters behavior in work sessions based on sequences of user interactions. Then, we perform a fine-grained analysis where we consider the type of each question presented within the frameset (these can be multi-choice, single-choice, or T/F questions). Our study involves 219 students, 224 framesets, and 15,521 work sessions across three semesters. We find that credit-seeking behavior is correlated with lower learning outcomes for students. We also find that the type of question is a key factor in whether students use credit-seeking behavior. The implications of our research suggest that educational software should be designed to minimize opportunities for credit-seeking behavior and promote genuine engagement with the material.
  • Species Composition, Ecological Preferences, and Chromosomal Polymorphism of Malaria Mosquitoes of the Crimean Peninsula and the Black Sea Coast of the Caucasus
    Moskaev, Anton V.; Bega, Anna G.; Brusentsov, Ilya I.; Naumenko, Anastasia N.; Karagodin, Dmitriy A.; Razumeiko, Vladimir N.; Andrianov, Boris V.; Goryacheva, Irina I.; Lee, Elizaveta Y.; Panov, Vladimir I.; Sharakhov, Igor V.; Sharakhova, Maria V.; Gordeev, Mikhail I. (MDPI, 2025-04-01)
    In this study, we sampled malaria mosquito larvae in natural and artificial breeding places to study the geographical distribution, ecological preferences, and chromosomal variability of different species of the genus Anopheles in the territory of the Crimean Peninsula and the Black Sea coast of the Caucasus. Species were diagnosed using a combination of morphological, cytogenetic, and molecular markers. The ecological conditions of the larval habitats, such as dissolved oxygen content in the water, acidity, salinity, and temperature, were measured. Seven species of malaria mosquitoes were identified in the pool of 2229 individual mosquitoes collected at 56 breeding sites, including An. atroparvus, An. claviger, An. daciae (formerly identified as An. messeae s. l.), An. hyrcanus, An. maculipennis s. s., An. plumbeus, and An. melanoon. The previously recorded species of An. algeriensis, An. messeae s. s., An. sacharovi, and An. superpictus were not found in this study. Anopheles maculipennis was dominant in typical anophylogenic water bodies. Anopheles plumbeus, which used to breed mainly in tree holes in coastal forests, has spread to urban settlements along the Black Sea coast and breeds in artificial containers. Chromosomal polymorphism was studied and found in An. atroparvus and An. daciae populations. Differences in the chromosomal composition of An. daciae populations in Crimea and on the Black Sea coast of the Caucasus were revealed. The Crimean population had a low level of polymorphism in autosomal inversions. The data obtained in this study can be used to inform a better control of potential malaria vectors in the Black Sea coastal region.
  • Pulsed Electromagnetic Field Therapy Alters the Genomic Profile of Bladder Cancer Cell Line HT-1197
    Sandberg, Maxwell; Whitman, Wyatt; Bissette, Randall; Ross, Christina; Tsivian, Matvey; Walker, Stephen J. (MDPI, 2025-04-04)
    Background/Objectives: Pulsed electromagnetic field (PEMF) therapy involves the use of magnetic waveform energy for targeted treatment delivery. This technique has shown promising results in the treatment of various cancers. Currently, treatment of bladder cancer is highly invasive, involving intravesical chemotherapy or radical cystectomy. The potential therapeutic effects of PEMF therapy on bladder cancer are a relatively new and understudied area; therefore, the goal of this investigation was to gain mechanistic insight by examining the effects of PEMF therapy on a bladder cancer cell line in vitro. Methods: Cells from the bladder cancer cell line HT-1197 were cultured and incubated with (treatment group) or without (control group) PEMF therapy for one hour each day for five days. Cell counts were compared using Incucyte® data to determine proliferation rates. At days 1 and 5, total RNA was isolated from cells, and following quantity and quality checks, gene expression was compared between the two groups. Proliferation rates from cell line HT-1197 were compared to prior published results on the bladder cancer cell line HT-1376. Results: HT-1197 cells treated with PEMF therapy had slower proliferation rates compared to controls (p < 0.05), but HT-1376 cells did not (p > 0.05). Principal component analysis showed complete separation of treated and untreated cells, with PEMF treatment accounting for 76% of the variation between the groups. Expression of numerous genes and cancer-related pathways was altered in the treated cells relative to the controls. Conclusions: Bladder cancer HT-1197 cells treated with PEMF therapy had slower proliferation and corresponding changes in gene expression. Several cancer-relevant pathways were differentially regulated following PEMF treatment. The conclusions are limited by the lack of a control healthy urothelial cell line in the experiments. Despite this shortcoming, our results suggest that PEMF therapy may be a promising avenue for further research in the treatment of bladder cancer.
  • Multi-Mode Flight Simulation and Energy-Aware Coverage Path Planning for a Lift+Cruise QuadPlane
    Mathur, Akshay; Atkins, Ella (MDPI, 2025-04-08)
    This paper describes flight planning supported by modeling, guidance, and feedback control for an electric Vertical Take-Off and Landing (eVTOL) QuadPlane small Uncrewed Aircraft System (sUAS). Five Lift+Cruise sUAS waypoint types are defined and used to construct smooth flight path geometries and acceleration profiles. Novel accelerated coverage flight plan segments for hover (Lift) and coverage (Cruise) waypoint types are defined as a complement to traditional fly-over, fly-by, and Dubins path waypoint transit solutions. Carrot-chasing guidance shows a tradeoff between tracking accuracy and control stability as a function of the carrot time step. Experimentally validated aerodynamic and thrust models for vertical, forward, and hybrid flight modes are developed as a function of airspeed and angle of attack from wind tunnel data. A QuadPlane feedback controller augments classical multicopter and fixed-wing controllers with a hybrid control mode that combines multicopter and aircraft control actuators to add a controllable pitch degree of freedom at the cost of increased energy use. Multi-mode flight simulations show Cruise mode to be the most energy efficient with a relatively large turning radius constraint, while quadrotor mode enables hover and smaller radius turns. Energy efficiency analysis over QuadPlane plans with modest inter-waypoint distances indicates cruise or aircraft mode is 30% more energy efficient overall than quadrotor mode. Energy-aware coverage planner simulation results show fly-coverage (cruise) waypoints are always the most efficient given long distances between waypoints. A Pareto analysis of energy use versus area coverage is presented to analyze waypoint-type tradeoffs in case studies with closely spaced waypoints. Coverage planning and guidance methods from this paper can be applied to any Lift+Cruise aircraft configuration requiring waypoint flight mode optimization over energy and coverage metrics.
  • An Application of Explainable Multi-Agent Reinforcement Learning for Spectrum Situational Awareness
    Perini, Dominick J.; Muller, Braeden P.; Kopacz, Justin; Michaels, Alan J. (MDPI, 2025-04-10)
    Allocating low-bandwidth radios to observe a wide portion of a spectrum is a key class of search-optimization problems that requires system designers to leverage limited resources and information efficiently. This work describes a multi-agent reinforcement learning system that achieves a balance between tuning radios to newly observed energy while maintaining regular sweep intervals to yield detailed captures of both short- and long-duration signals. This algorithm, which we have named SmartScan, and system implementation have demonstrated live adaptations to dynamic spectrum activity, persistence of desirable sweep intervals, and long-term stability. The SmartScan algorithm was also designed to fit into a real-time system by guaranteeing a constant inference latency. The result is an explainable, customizable, and modular approach to implementing intelligent policies into the scan scheduling of a spectrum monitoring system.
  • Effects of Embryonic Thermal Manipulation on Body Performance and Cecum Microbiome in Broiler Chickens Following a Post-Hatch Lipopolysaccharide Challenge
    Hundam, Seif; Al-Zghoul, Mohammad Borhan; Ababneh, Mustafa; Alanagreh, Lo’ai; Dahadha, Rahmeh; Mayyas, Mohammad; Alghizzawi, Daoud; Mustafa, Minas A.; Gerrard, David E.; Dalloul, Rami A. (MDPI, 2025-04-17)
    Thermal manipulation (TM) during embryogenesis has emerged as a promising strategy to enhance post-hatch performance and improve resilience to environmental and bacterial stress, which offers a potential alternative to reduce the reliance on antibiotic growth promoters (AGPs) in broiler production. This study investigated TM’s ability to modulate broilers’ cecal microbiota and enhance resilience to lipopolysaccharide (LPS)-induced stress. Eggs in the control group (CON) were incubated at 37.8 °C and 56% relative humidity (RH), while TM eggs were exposed to 39 °C and 65% RH for 18 h daily from embryonic days 10–18. Post-hatch, the LPS subgroups (LPS-CON, LPS-TM) received intraperitoneal LPS injections, and body weight (BW) and temperature (BT) were monitored. Cecal samples were collected for microbiome sequencing. Alpha diversity showed no differences (p > 0.05), but beta diversity revealed differences between groups (PERMANOVA, p < 0.05). Firmicutes and Bacteroidota dominated the microbiota at the phylum level. Oscillospirales were enriched in the TM groups (p < 0.001) and Lactobacillales were increased in the LPS-CON group (p < 0.019). LPS reduced BT in the CON group (p < 0.01), but LPS-TM birds bypassed hypothermia. LPS significantly reduced BW (p < 0.001), while TM had no significant effect. These findings demonstrate TM’s enduring influence on gut microbiota and stress resilience, highlighting its potential to reduce antibiotic reliance and mitigate antimicrobial resistance (AMR) in poultry production.
  • Microgrid Reliability Incorporating Uncertainty in Weather and Equipment Failure
    Nallainathan, Sakthivelnathan; Arefi, Ali; Lund, Christopher; Mehrizi-Sani, Ali (MDPI, 2025-04-17)
    Solar photovoltaic (PV) and wind power generation are key contributors to the integration of renewable energy into modern power systems. The intermittent and variable nature of these renewables has a substantial impact on the power system’s reliability. In time-series simulation studies, inaccuracies in solar irradiation and wind speed parameters can lead to unreliable evaluations of system reliability, ultimately resulting in flawed decision making regarding the investment and operation of energy systems. This paper investigates the reliability deviation due to modeling uncertainties in a 100% renewable-based system. This study employs two methods to assess and contrast the reliability of a standalone microgrid (SMG) system in order to achieve this goal: (i) random uncertainty within a selected confidence interval and (ii) splitting the cumulative distribution function (CDF) into five regions of equal probability. In this study, an SMG system is modeled, and loss of load probability (LOLP) is evaluated in both approaches. Six different sensitivity analysis studies, including annual load demand growth, are performed. The results from the simulations demonstrate that the suggested methods can estimate the reliability of a microgrid powered by renewable energy sources, as well as its probability of reaching certain levels of reliability.
  • The Quantification of Morphological Variation and Development of Morphology-Based Keys to Identify Species of Fusconaia and Pleurobema (Unionidae) in the Green River, Kentucky, USA
    Olivera-Hyde, Miluska; Jones, Jess W.; Hallerman, Eric M. (MDPI, 2025-04-21)
    We quantified morphological variation among genetically identified specimens of Fusconaia flava, F. subrotunda, Pleurobema cordatum, P. plenum, P. sintoxia, and P. rubrum inhabiting the Green River, Kentucky, species with shells that are morphologically similar to each other and thus difficult to identify. Molecular identifications then were compared with phenotype-based identifications by experts, who on average correctly identified 70% of the specimens. Expert identification of the putative species P. rubrum and P. sintoxia resulted in them usually being identified as the latter. Multi-variable decision tree analysis was conducted to determine the best suite of morphological variables for identifying live mussels and shells to species. Cross-validation error rates for these analyses were 12.6% and 4.14% for live mussels and shells, respectively. Both random forest and decision tree analyses showed the most important variables to be the presence/absence of a sulcus and shell shape (trapezoidal, circular, oval, equilateral triangle, or isosceles triangle). Dichotomous keys for identifying shells and live mussels were developed based on key morphological characteristics readily identifiable in the field, including foot color, beak direction, and beak position relative to the anterior margin. However, a definitive identification of these species may still need to rely on molecular methods, especially for endangered species.
  • Analytical Investigation of Electromechanical Hierarchical Metamaterials for Vibration Attenuation and Energy Harvesting
    Mebrat, Ashenafi Abebe; LeGrande, Joshua; Barry, Oumar (MDPI, 2025-03-21)
    This work presents a theoretical study of outward and inward hierarchical metamaterials. Hierarchically configured multiple electromechanical resonators with shunt circuits are implemented, maintaining the same overall mass as that of a comparable single resonator metamaterial. The governing equations of motion for the outward and inward hierarchical configurations are derived. Dispersion relations are determined for each configuration with varying system parameters to identify key design parameters and assess their impact on the system’s dynamic behavior. Furthermore, outer mass displacement transmissibility and normalized total power output of finite chain hierarchical metamaterials are compared to observe vibration attenuation and energy harvesting capacity. The results reveal that the band structure of the hierarchical electromechanical metamaterials depends on the configuration type, the resonator masses, the electromechanical coupling coefficient, and the resistance of the shunt circuit. The first-order hierarchy offers a greater total band gap width, increased bandwidth, and greater flexibility in tuning the band structure. Finite chain transmissibility analysis demonstrates that, compared to the baseline performance of the zero-order hierarchy, the first-order hierarchy exhibits superior abilities in vibration attenuation and energy harvesting for the same total mass. The ideal design requires careful consideration of the resonator masses and their configuration, electromechanical coupling coefficient, and resistance of the shunt circuits. This theoretical work provides a foundation for designing lightweight hierarchical metamaterials for simultaneous vibration attenuation and energy harvesting.
  • Understanding Polysiloxane Polymer to Amorphous SiOC Conversion During Pyrolysis Through ReaxFF Simulation
    Lu, Kathy; Chaney, Harrison (MDPI, 2025-03-22)
    A significant challenge during the polymer-to-ceramic pyrolysis conversion is to understand the polymer-to-ceramic atomic evolution and correlate the composition changes with the precursor molecular structures, pyrolysis conditions, and resulting ceramic characteristics. In this study, a Reactive Force Field (ReaxFF) simulation approach has been used to simulate silicon oxycarbide (SiOC) ceramic formation from four different polysiloxane precursors. For the first time, we show atomically that pyrolysis time and temperature proportionally impact the new Si-O rich and C rich cluster sizes as well as the composition separation of Si-O from C. Polymer side groups have a more complex effect on the Si-O and C cluster separation and growth, with ethyl group leading to the most Si-O cluster separation and phenyl group leading to the most C cluster separation. We also demonstrate never-before correlations of gas release with polymer molecular structures and functional groups. CH4, C2H6, C2H4, and H2 are preferentially released from the pyrolyzing systems. The sequence is determined by the polymer molecular structures. This work is the first to atomically illustrate the innate correlations between the polymer precursors and pyrolyzed ceramics.
  • Feasibility of Little Cherry/X-Disease Detection in Prunus avium Using Field Asymmetric Ion Mobility Spectrometry
    Kothawade, Gajanan S.; Khot, Lav R.; Chandel, Abhilash K.; Molnar, Cody; Harper, Scott J.; Wright, Alice A. (MDPI, 2025-03-25)
    Little cherry disease (LCD) and X-disease have critically impacted the Pacific Northwest sweet cherry (Prunus avium) industry. Current detection methods rely on laborious visual scouting or molecular analyses. This study evaluates the suitability of field asymmetric ion mobility spectrometry (FAIMS) for rapid detection of LCD and X-disease infection in three sweet cherry cultivars (‘Benton’, ‘Cristalina’, and ‘Tieton’) at the post-harvest stage. Stem cuttings with leaves were collected from commercial orchards and greenhouse trees. FAIMS operated at 1.5 L/min and 50 kPa, was used for headspace analysis. Molecular analyses confirmed symptomatic and asymptomatic samples. FAIMS data were processed for ion current sum (Isum), maximum ion current (Imax), and area under the curve (IAUC). Symptomatic samples showed higher ion currents in specific FAIMS regions (p < 0.05), with clear differences between symptomatic and asymptomatic samples across compensation voltage and dispersion field ranges. Cultivar-specific variation was also observed in the data. FAIMS spectra for LCD/X-disease symptomatic samples differed from those for asymptomatic samples in other Prunus species, such as peach and nectarines. These findings support FAIMS as a potential diagnostic tool for LCD/X disease. Further studies with controlled variables and key growth stages are recommended to realize early-stage detection.
  • Blind Interference Suppression with Uncalibrated Phased-Array Processing
    Lusk, Lauren O.; Gaeddert, Joseph D. (MDPI, 2025-03-27)
    As the number of devices using wireless communications increases, the amount of usable radio frequency spectrum becomes increasingly congested. As a result, the need for robust, adaptive communications to improve spectral efficiency and ensure reliable communication in the presence of interference is apparent. One solution is using beamforming techniques on digital phased-array receivers to maximize the energy in a desired direction and steer nulls to remove interference; however, traditional phased-array beamforming techniques used for interference removal rely on perfect calibration between antenna elements and precise knowledge of the array configuration. Consequently, if the exact array configuration is not known (unknown or imperfect assumption of element locations, unknown mutual coupling between elements, etc.), these traditional beamforming techniques are not viable, so a beamforming approach with relaxed requirements (blind beamforming) is required. This paper proposes a novel blind beamforming approach to address complex narrowband interference in spectrally congested environments where the precise array configuration is unknown. The resulting process is shown to suppress numerous interference sources, all without any knowledge of the primary signal of interest. The results are validated through wireless laboratory experimentation conducted with a two-element array, verifying that the proposed beamforming approach achieves a similar performance to the theoretical performance bound of receiving packets in additive white Gaussian noise (AWGN) with no interference present.
  • Consumer Preference and Purchase Intention for Plant Milk: A Survey of Chinese Market
    Wang, Aili; Tan, Chunhua; Yu, Wenwen; Zou, Liang; Wu, Dingtao; Liu, Xuanbo (MDPI, 2025-04-01)
    Plant milks are considered to be nutritious, sustainable, and vegetarian food products, and they have been the fastest growing beverages in the past decade in China. However, few studies have investigated consumers’ demands and purchase behaviors with respect to plant milks. Through an online questionnaire (n = 1052 valid responses), this study identified the factors that influenced individuals’ purchase intentions, purchase behaviors, attitudes, and demands with respect to current and future plant milk products. Through descriptive analysis and PCA, this study revealed that nutritional value (63.6%), taste (56.3%), and calories (42.8%) were the top three factors that Chinese consumers most cared about regarding plant milks. In the current Chinese market, coconut milk is the most popular plant milk with the highest purchase rate (61.2%), followed by soymilk (53.9%). Male consumers preferred plant milk with higher protein content and fortified with antioxidants, while female consumers preferred plant milk low in calories and enriched with collagen, dietary fiber, and probiotics. Chinese consumers are willing to pay higher prices for plant milks with enhanced nutritional value, improved product quality, and strengthened safety assurances. Innovative forms of plant milk, such as bean milk, rice milk, and quinoa milk, may be developed to satisfy the diversified needs of consumers.
  • Phytochemical Composition and Effects of Aqueous Extracts from Moringa oleifera Leaves on In Vitro Ruminal Fermentation Parameters
    Oliveira, Inessa Steffany Torres de; Fernandes, Tatiane; Santos, Aylpy Renan Dutra; González Aquino, Carolina; Vega Britez, Gustavo Daniel; Vargas Junior, Fernando Miranda de (MDPI, 2025-01-20)
    This study evaluated the phytochemical composition of aqueous extracts of Moringa oleifera (MO) obtained by maceration, decoction, and infusion of fresh or dried leaves and their effects on in vitro ruminal fermentation parameters. Phytochemical prospecting analyses were conducted to determine the bioactive compounds in each aqueous extract. Regarding the in vitro ruminal fermentation study, the seven treatments were the following: no addition of extract or control (CON); extract obtained by maceration of fresh leaves (MFL); extract obtained by maceration of dry leaves (MDL); extract obtained by decoction of the fresh leaves (DFL); extract obtained by decoction of dry leaves (DDL); extract obtained by infusion of fresh leaves (IFL) and extract obtained by infusion of dry leaves (IDL). The concentration of all bioactives (saponins, flavonoids, tannins, and alkaloids) quantified was higher when fresh MO leaves were used (p < 0.001). DFL and DDL provided less elimination of azino-bis radicals. On the other hand, MFL resulted in a greater elimination of these radicals. Extracts obtained from fresh leaves resulted in a greater total production of short-chain fatty acids, acetate, and butyrate (p < 0.05). Compared to the control treatment, the inclusion of extracts obtained from fresh leaves provided a higher concentration of propionate (p = 0.049). It is thereby concluded that the use of fresh MO leaves for the production of aqueous extracts is the most recommended, as it results in a higher concentration of bioactive compounds. The use of aqueous extracts of fresh MO leaves increases the total production of fatty acids but does not change their proportion.
  • Enhancing Place Attachment Through Developing Public Open Places: A Cross-Cultural Study in Gold Coast, Australia
    Ghasemieshkaftaki, Marzieh; Dupre, Karine; Campbell, Jennifer; Fernando, Ruwan (MDPI, 2025-01-24)
    Urban studies research has increasingly focused on placemaking and place attachment in public open places. While several studies have explored how immigrants interact with these places, this study investigates how cultural differences affect immigrants’ place attachment, providing a deeper understanding of inclusive urban design. Semi-structured interviews were conducted with 21 students from India, Iran, China, and Australia, in Southport, a preferred neighborhood for immigrants on the Gold Coast, Australia. NVivo software was used to analyze the data and extract themes. The findings highlighted that, despite universal factors such as natural environments and social opportunities, cultural factors are crucial in shaping individuals’ experiences.