bluuebunny/crossref_metadata_2025 huggingface dataset:
Fuelless On-Orbit Assembly of a Large Space Truss Structure Using Repulsion of the Service Spacecraft by Robotic Manipulators
Authors: Orlov Vladislav , Monakhova Uliana , Ovchinnikov Mikhail , Ivanov Danil
Published: August 2024

A servicing spacecraft motion control approach for the problem of on-orbit truss structure assembly is developed in this paper. It is considered that a cargo container with a rod set and servicing spacecraft are in orbit initially. The assembly procedure is based on spacecraft free-flight motion between the structure’s specified points. The spacecraft is equipped with two robotic manipulators capable of attaching to the structure and holding rods. In addition, the spacecraft can repulse from the structure with a given relative velocity using a manipulator, so the spacecraft and the structure receive impulses. The repulsion velocity vector is calculated in order to reach the structure target point to deliver and install the rod into the truss structure, or to reach the cargo container and take a rod. The problem of searching the repulsion velocity is formulated as an optimization problem with constraints, taking into account the limited value of the repulsion velocity, collision avoidance with structure, restrictions on the angular velocity and translational motion of the structure in the orbital reference frame. This problem is solved numerically with an initial guess vector obtained analytically for simplified motion cases. The application of the proposed control scheme to the assembly of a truss-based antenna is demonstrated. It is shown that the servicing spacecraft is successfully transferred between the structure points by means of manipulator repulsion. Main features and limitations of the assembly problem using a spacecraft with two manipulators are discussed.
Development of a Small Dual-Chamber Solar PV-Powered Evaporative Cooling System for Fruit and Vegetable Cooling with Techno-Economic Assessment
Authors: Ndukwu Macmanus Chinenye , Usoh Godwin , Akpan Godwin , Akuwueke Leonard , Ekop Inemesit , Etim Promise , Sam Emmanuel Okon , Oriaku Linus , Omenyi Prince , Oleka Emeka , Abam Fidelis
Published: August 2024

This study evaluates a solar PV-powered evaporative cooling system for vegetable cooling. The system features dual cooling chambers with two different biomass pads, operating at different temperatures. To assess its potential, the research examines the evolution of temperature and humidity of the cooling chamber, evaporative effectiveness, cooling capacity, coefficient of performance (COP), energy metrics, greenhouse gas emissions, and overall cost. The results show that the system achieved a temperature depression range of 0.22 to 5.2 °C and 0.57 to 10.94 °C for wood shavings and polyurethane foam, respectively, under no-load conditions, while the values were 0.79 to 4.7 °C and 1.22 to 9.88 °C, with average values of 3.09 and 7.0 °C, for the same materials under loaded conditions. Loaded conditions also yielded a cooling capacity of 5.7 to 33.93 W for wood shavings and 8.13 to 75.55 W for polyurethane foam. The cooling efficiency ranged from 19.9 to 96.42% for polyurethane foam and 3.62 to 60% for wood shavings. The system’s COP was higher than that of solar-powered mechanical chillers, ranging from 2.37 to 22.92. The energy production factor was 2.3 to 2.4, with a lifecycle conversion efficiency of 0.5 and an energy payback time of 1.1 and 2.2 years for using polyurethane foam and wood shavings, respectively. The net present value was positive, and the levelized cost of energy was low, at 36.7 to 38.3 NGN/kWh (0.043–0.045 USD/kWh), making it a viable alternative to grid-based energy systems in Nigeria. Additionally, the system offers significant CO2 mitigation potential, with estimated carbon credits of NGN 65,059 (USD 71.56) and NGN 98,576.49 (USD 108.43) over its lifetime.
Observed Energy Use by Broiler and Pullet Farms
Authors: Turner Aaron P. , Chastain John P. , Massey Hunter F.
Published: August 2024

Evaluating farm-scale energy used for broiler production can provide insight into how these facilities use energy and allow for seasonal and managerial influences to be evaluated. This study evaluated farm-scale energy consumption for South Carolina broiler production using energy records from 17 broiler and 4 pullet farms. Monthly electric use showed low to moderate correlation (r ranging from 0.476–0.630) with ambient temperature but had limited predictive usefulness. There was no clear pattern in monthly electrical energy use for broiler barns. However, pullet barns were more consistent and could be grouped into seasons. No significant differences (p < 0.05) in annual electric or gas use were observed between farms with generally better equipment and otherwise similar farms, but production type did influence annual electric use. The average annual electrical use was 23.6 kWh m−2 for farms producing larger birds, 8.7 kWh m−2 for those producing smaller birds, and 17.0 kWh m−2 for pullet farms. Electrical energy use accounted for 37% of total energy in broiler barns and 32% of energy in pullet barns. Combined electric and gas consumption averaged 214 MJ m−2 yr−1 across all farms. These findings help better quantify farm-scale energy used for broiler production and provide benchmark values for energy use.
Application of Artificial Intelligence to Forecast Drought Index for the Mekong Delta
Authors: Ha Duong Hai , Duc Phong Nguyen , Luong Thuan Ha , Duc Thang Tang , Ngoc Thang Trinh , Minh Tien Nguyen , Minh Tu Nguyen
Published: August 2024

Droughts have a substantial impact on water supplies, agriculture, and ecosystems worldwide. Agricultural sustainability and production in the Mekong Delta of Vietnam are being jeopardized by droughts caused by climate change. Conventional forecasting methods frequently struggle to comprehend the intricate dynamics of meteorological occurrences connected to drought, necessitating the use of sophisticated prediction techniques. This study assesses the effectiveness of various statistical models (ARIMA), machine learning, and deep learning models (Gradient Boosting, XGBoost, RNN, and LSTM) in forecasting the SPEI over different time periods (1, 3, 6, and 12 months) across six prediction intervals. The models were developed and evaluated using data from 11 meteorological stations spanning from 1985 to 2022. These models incorporated various climatic variables, including precipitation, temperature, humidity, potential evapotranspiration (PET), Southern Oscillation Index (SOI) Anomaly, and sea surface temperature in the NINO4 region (SST_NINO4). The results demonstrate that XGBoost and LSTM models exhibit outstanding performance, showcasing lower error metrics and higher R² values compared to Gradient Boosting and RNN. The performance of the model fluctuated depending on the forecast step, with error metrics often increasing with longer prediction horizons. The use of climatic indices improved the accuracy of the model. These findings are consistent with earlier research on drought episodes in the Mekong Delta and support studies from other areas that show the effectiveness of advanced modeling tools for predicting droughts. The work emphasizes the capacity of machine learning and deep learning models to enhance the precision of drought forecasting, which is vital for efficient water resource management and agricultural planning in places prone to drought.
Comparative Targeted Metabolomics of Ischemic Stroke: Thrombi and Serum Profiling for the Identification of Stroke-Related Metabolites
Authors: Karmelić Ivana , Rubić Ivana , Starčević Katarina , Ozretić David , Poljaković Zdravka , Sajko Mia Jurilj , Kalousek Vladimir , Kalanj Rafaela , Rešetar Maslov Dina , Kuleš Josipa , Roje Bedeković Marina , Sajko Tomislav , Rotim Krešimir , Mrljak Vladimir , Fabris Dragana
Published: August 2024

Ischemic stroke is one of the leading causes of death and permanent disability in the world. Rapid diagnosis and intervention are crucial for reducing its consequences on individuals and societies. Therefore, identifying reliable biomarkers for early detection, prognostics, and therapy can facilitate the early prediction and prevention of stroke. Metabolomics has been shown as a promising tool for biomarker discovery since many post-ischemic metabolites can be found in the plasma or serum of the patient. In this research, we performed a comparative targeted metabolomic analysis of stroke thrombi, stroke patient serums, and healthy control serums in order to determine the alteration in the patients’ metabolomes, which might serve as biomarkers for early prediction or stroke prevention. The most statistically altered metabolites characterized in the patient serums compared with the control serums were glutamate and serotonin, followed by phospholipids and triacylglycerols. In stroke thrombi compared with the patients’ serums, the most significantly altered metabolites were classified as lipids, with choline-containing phospholipids and sphingomyelins having the highest discriminatory score. The results of this preliminary study could help in understanding the roles of different metabolic changes that occur during thrombosis and cerebral ischemia and possibly suggest new metabolic biomarkers for ischemic stroke.
Impact of Coffee Consumption on Subjective Perception and Inflammatory Markers in Patients with Inflammatory Bowel Diseases
Authors: Neamți Lidia , Gheorghe Simona R. , Ventuneac Amalia , Drugan Tudor , Drugan Cristina , Silaghi Ciprian N. , Ciobanu Lidia , Crăciun Alexandra M.
Published: August 2024

Inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are chronic conditions marked by persistent inflammation, impacting patients’ quality of life. This study assessed differences in coffee consumption between CD and UC patients and its potential effects on the subjective perception and objective changes in inflammation markers in these two categories of patients. Using questionnaires, coffee consumption patterns, and perceived symptom effects were evaluated. Biological samples were collected to measure the following inflammatory markers: leukocytes, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and fecal calprotectin (FC). Among 148 patients, 60% reported regular coffee consumption, with no significant difference between CD and UC patients. While 45.93% perceived no impact on symptoms, 48% of those reporting exacerbation continued their regular coffee consumption. FC values were significantly lower in coffee consumers than in non-consumers (p < 0.05), particularly in those consuming natural coffee (p < 0.001), and the case was observed for UC patients (p < 0.05). No significant differences were observed in other inflammatory markers, regardless of coffee type, frequency, or milk addition. This study highlights the commonality of coffee consumption among IBD patients and the association of lower FC levels with coffee consumption, especially in UC patients, suggesting that coffee may influence intestinal inflammatory responses.
Antimicrobial Efficacy of Chemomechanical Carie Removal Agents—A Systematic Integrative Review
Authors: Janvier Adélaïde , Maziere Marie , Rodrigues Célia F. , Lobo Ana Paula , Rompante Paulo
Published: August 2024

Background: Dental caries is the most common oral disease in the world. When treatable, the drilling method continues to be used. This technique has its disadvantages because it is invasive and nonspecific. Chemomechanical carious tissue removal agents (CCRAs) such as Carisolv™ or Papacarie® are non-invasive products that allow for the specific elimination of infected dentin. On the other hand, cariogenic bacteria are largely responsible for the initiation and development of lesions. Objectives: The aim is to analyze whether CCRAs have a relevant antimicrobial effect on cariogenic bacteria. Methods: A bibliographic search strategy was carried out in online databases using PRISMA 2020. The evaluation of the antibacterial efficacy of CCRAs was carried out through the analysis of the reduction in CFUs of cariogenic bacteria, and the presence of bacterial deposits, TVC, SVC and LVC by comparison with conventional drilling methods. Results: The results showed that the percentage of reduction in TVC, SVC and LVC for each agent is mostly high, but not significantly different from mechanical methods. The best results were found with CCRAs when compared to polymeric drills. The results also showed that there is a lack of methodological standardization. Conclusions: CCRAs have been shown to have a relevant antimicrobial effect on cariogenic bacteria; however, more studies need to be carried out using standardized methodologies.
Current Management of Non-ST-Segment Elevation Acute Coronary Syndrome
Authors: Díez-Villanueva Pablo , Jiménez-Méndez César , Cepas-Guillén Pedro , Arenas-Loriente Andrea , Fernández-Herrero Ignacio , García-Pardo Héctor , Díez-Delhoyo Felipe
Published: August 2024

Cardiovascular disease constitutes the leading cause of morbimortality worldwide. Non-ST-segment elevation acute coronary syndrome (NSTE-ACS) is a common cardiovascular condition, closely related to the ageing population and significantly affecting survival and quality of life. The management of NSTE-ACS requires specific diagnosis and therapeutic strategies, thus highlighting the importance of a personalized approach, including tailored antithrombotic therapies and regimens, combined with timely invasive management. Moreover, specific and frequent populations in clinical practice, such as the elderly and those with chronic kidney disease, pose unique challenges in the management of NSTE-ACS due to their increased risk of ischemic and hemorrhagic complications. In this scenario, comprehensive management strategies and multidisciplinary care are of great importance. Cardiac rehabilitation and optimal management of cardiovascular risk factors are essential elements of secondary prevention since they significantly improve prognosis. This review highlights the need for a personalized approach in the management of NSTE-ACS, especially in vulnerable populations, and emphasizes the importance of precise antithrombotic management together with tailored revascularization strategies, as well as the role of cardiac rehabilitation in NSTE-ACS patients.
Microscopic and Color Changes in Direct Dental Restorative Composite Resins upon Immersion in Beverages: Characterization by Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS)
Authors: Hajdu Adrian Ioan , Dumitrescu Ramona , Balean Octavia , Jumanca Daniela , Sava-Rosianu Ruxandra , Floare Lucian , Bolchis Vanessa , Vlase Titus , Galuscan Atena
Published: August 2024

This study aimed to evaluate the staining sensitivity and surface changes in recent composite resins (Herculite Ultra XRV (Kerr, Bolzano, Italy), G-ænial A’CHORD (GC Corp, Tokyo, Japan), and Omnichroma (Yamaguchi, Japan)) when exposed to common beverages such as coffee, red wine, and Coca-Cola. A total of 60 disk-shaped specimens were prepared from three different resin composites (n = 20 each). The specimens were exposed to coffee, red wine, and Coca-Cola for 10 days. Color measurements were taken using a spectrophotometer, and surface morphology and elemental composition were analyzed using SEM and EDS. The SEM and EDS analyses revealed significant changes in the surface morphology and elemental composition of the composites after immersion. Coffee and wine caused significant surface degradation, whereas Coca-Cola resulted in the greatest degree of surface and elemental variations. Color changes (ΔE = 4 ± 0.52) were most notable in Coca-Cola for Herculite Ultra XRV (Kerr, Italy), in red wine for G-ænial A’CHORD (GC Corp, Japan) (ΔE = 12.51 ± 0.38), and in coffee for Omnichroma (Yamaguchi, Japan) (ΔE = 10.85 ± 1.03). The tested beverages significantly affected both the surface condition and the chemical composition of the resin at the surface level. These findings highlight the importance of understanding the effects of common dietary beverages on dental composites.
A Very Early Diagnosis of Complete Androgen Insensitivity Syndrome Due to a Novel Variant in the AR Gene: A Neonatal Case Study
Authors: Ferrante Rossella , Tumini Stefano , Saltarelli Maria Alessandra , Di Rado Sara , Scorrano Vincenzo , Tommolini Maria Lucia , Zucchelli Mirco , Lauriola Federico , Lisi Gabriele , Lauriti Giuseppe , Marino Nino , Stuppia Liborio , Rossi Claudia , Bucci Ines
Published: August 2024

Androgen insensitivity syndrome (AIS) is one of the most common Disorders of Sexual Differentiation (DSDs). AIS is characterized by an X-linked recessive inheritance pattern associated with variants in the androgen receptor (AR) gene that affects the masculinization process in individuals with XY karyotype. Here, we report a neonatal case of a very early diagnosis of complete AIS due to a novel variant in the AR gene. In the present case, after the clinical evaluation, the infant has undergone the following tests: biochemical analyses, including newborn screening workflow, karyotype analysis, and Next-Generation Sequencing (NGS) panel of 50 genes involved in DSDs. The NGS analysis identified a missense variant, c.2108C>A, in the AR gene. According to a cytogenetic analysis, the patient presented a 46, XY karyotype, thus the resulting hemizygote for the AR gene variant. The variant is not currently described in the literature nor in the ClinVar database. However, according to computational models, the variant could have a pathogenetic effect. This clinical case reveals a novel variant of the AR gene with a possible pathogenetic effect associated with AIS and highlights the importance of a multidisciplinary approach for the timely diagnosis and appropriate follow-up of the patient.
Influence of Age and Sex on Post-Craniotomy Headache
Authors: Kim Jong-Ho , Han Sung-Woo , Kwon Young-Suk , Lee Jae-June , Sohn Jong-Hee
Published: August 2024

Post-craniotomy headache (PCH) is a common postoperative complication, and some of these patients progress to chronic PCH (CPCH). We aimed to identify clinical variables associated with PCH and its progression to CPCH, especially possible associations between age and sex differences. Therefore, we examined clinical information on PCH using the Clinical Data Warehouse over 10 years. Of the 1326 patients included, 927 patients (69.9%) experienced PCH. In multivariate analysis for PCH, age was inversely related to risk (p = 0.003), and being female showed a significant association with an increased risk of PCH (p = 0.002). There was also a significant inverse relationship between age and severity of the worst headache, with younger female patients reporting greater severity of the worst headache (p < 0.001). Of the 927 patients who experienced PCH, 319 (34.4%) progressed to CPCH. Sex was a significant factor, with females having a higher risk of developing CPCH compared to males (p < 0.001). In addition, the presence of preoperative headaches significantly increased the risk of CPCH (p = 0.001). The occurrence of PCH is associated with younger age and female sex. In particular, female sex and preoperative headaches increased the risk of developing CPCH. These clinical factors should be considered in patients undergoing neurosurgery.
The Proton Leak of the Inner Mitochondrial Membrane Is Enlarged in Freshly Isolated Pancreatic Islets
Authors: Alshafei Mohammed , Morsi Mai , Reschke Julia , Rustenbeck Ingo
Published: August 2024

In a number of investigations on the mechanism of the metabolic amplification of insulin secretion, differences between the response of freshly isolated islets and of islets cultured for one day have been observed. Since no trivial explanation like insufficient numbers of viable cells after cell culture could be found, a more thorough investigation into the mechanisms responsible for the difference was made, concentrating on the function of the mitochondria as the site where the metabolism of nutrient stimulators of secretion forms the signals impacting on the transport and fusion of insulin granules. Using combinations of inhibitors of oxidative phosphorylation, we come to the conclusion that the mitochondrial membrane potential is lower and the exchange of mitochondrial reducing equivalents is faster in freshly isolated islets than in cultured islets. The significantly higher rate of oxygen consumption in fresh islets than in cultured islets (13 vs. 8 pmol/min/islet) was not caused by a different activity of the F1F0-ATPase, but by a larger proton leak. These observations raise the questions as to whether the proton leak is a physiologically regulated pathway and whether its larger size in fresh islets reflects the working condition of the islets within the pancreas.
A Computational Approach to Demonstrate the Control of Gene Expression via Chromosomal Access in Colorectal Cancer
Authors: Pecka Caleb J. , Thapa Ishwor , Singh Amar B. , Bastola Dhundy
Published: August 2024

Background: Improved technologies for chromatin accessibility sequencing such as ATAC-seq have increased our understanding of gene regulation mechanisms, particularly in disease conditions such as cancer. Methods: This study introduces a computational tool that quantifies and establishes connections between chromatin accessibility, transcription factor binding, transcription factor mutations, and gene expression using publicly available colorectal cancer data. The tool has been packaged using a workflow management system to allow biologists and researchers to reproduce the results of this study. Results: We present compelling evidence linking chromatin accessibility to gene expression, with particular emphasis on SNP mutations and the accessibility of transcription factor genes. Furthermore, we have identified significant upregulation of key transcription factor interactions in colon cancer patients, including the apoptotic regulation facilitated by E2F1, MYC, and MYCN, as well as activation of the BCL-2 protein family facilitated by TP73. Conclusion: This study demonstrates the effectiveness of the computational tool in linking chromatin accessibility to gene expression and highlights significant transcription factor interactions in colorectal cancer. The code for this project is openly available on GitHub.
Enhanced Oxygen Vacancy Formation in CeO2-Based Materials and the Water–Gas Shift Performance
Authors: Kaewtong Sangaroon , Sesuk Thanathon , Tepamatr Pannipa
Published: August 2024

The role of dopants (Sm, Tb and Pr) on the water–gas shift performance of CeO2-based materials was studied. Modification of CeO2 with Sm significantly improved the water–gas shift performance. The catalytic activities of doped CeO2 were increased when compared with the catalytic activities of pure ceria (65% conversion at 600 °C for Ce5%SmO and 50% conversion at 600 °C for CeO2). The key factors driving the water–gas shift performance were reduction behavior and oxygen vacancy concentration. In the redox mechanism of the WGS reaction, CeO2 plays a crucial role in transferring oxygen to CO through changes in the oxidation state. Therefore, Sm is effective in catalyzing the water–gas shift activity because the addition of Sm into CeO2 decreases the surface reduction temperature and alters the oxygen transportation ability through the redox mechanism. XRD results suggested that Mn+ (M = Sm, Tb and Pr) incorporate into ceria lattice to form a solid solution resulting in unit cell enlargement. The defect structure inside the CeO2 lattice generates a strain on the oxide lattice and facilitates the generation of oxygen vacancies. XANES analysis revealed that Sm reduced CeO2 easily by transporting its electron into the d-orbitals of Ce, thus giving rise to more Ce3+ at the CeO2 surface. The presence of Ce3+ is a result of oxygen vacancy. Therefore, the high content of Ce3+ provides more oxygen vacancies. The oxygen vacancy formation results in easy oxygen exchange. Thus, reactive oxygen species can be generated and easily reduced by CO reactant, which enhances the WGS activity.
Post-Traumatic Psychological Experience of COVID-19 Survivors: A Descriptive Phenomenological Study
Authors: Al Nasiri Yusra , Al Balushi Amal , Al Balushi Saira , Al Alawi Kamila , Al Mashari Zainab , Al Muqimi Buthaina , Al Balushi Faiza , Al Awaidy Salah
Published: August 2024

Background: The rising incidence of COVID-19 cases is undeniably having a profound impact on the physiological and psychological welfare of individuals. The incident had the potential to significantly affect an individual’s quality of life, social interactions, and occupational performance. The study explored the experiences of individuals who recovered from COVID-19 and the impact of their illness on their psychological and overall well-being. Methods: A qualitative, phenomenological study was conducted in Oman among 15 patients aged 20 to 60 years, who had been hospitalized at Royal Hospital with moderate to severe symptoms and signs of COVID-19. An in-depth interview was used to collect data. Thematic analysis was carried out to analyze the data using the Braun and Clarke model framework for the analysis. Results: Three themes emerged from the study: (1) The impact of COVID-19 on the survivors; (2) factors that improved patients’ recovery; (3) lessons learned from COVID-19 pandemic. A recent study found important intrinsic and extrinsic factors that helped COVID-19 patients recover quickly. Conclusions: COVID-19 impacted the individuals’ physiological and psychological health. The findings can inform Oman’s psychological support services and raise awareness of the virus’s psychological impact on mental health. The study may help to design a tailored psychological intervention to improve the mental well-being of COVID-19 survivors for better experience and quality of life.
Unification of Mind and Matter through Hierarchical Extension of Cognition: A New Framework for Adaptation of Living Systems
Authors: Nakajima Toshiyuki
Published: August 2024

Living systems (LSs) must solve the problem of adapting to their environment by identifying external states and acting appropriately to maintain external relationships and internal order for survival and reproduction. This challenge is akin to the philosophical enigma of how the self can escape solipsism. In this study, a comprehensive model is developed to address the adaptation problem. LSs are composed of material entities capable of detecting their external states. This detection is conceptualized as “cognition”, a state change in relation to its external states. This study extends the concept of cognition to include three hierarchical levels of the world: physical, chemical, and semiotic cognitions, with semiotic cognition being closest to the conventional meaning of cognition. This radical extension of the cognition concept to all levels of the world provides a monistic model named the cognizers system model, in which mind and matter are unified as a single entity, the “cognizer”. During evolution, LSs invented semiotic cognition based on physical and chemical cognitions to manage the probability distribution of events that occur to them. This study proposes a theoretical model in which semiotic cognition is an adaptive process wherein the inverse causality operation produces particular internal states as symbols that signify hidden external states. This operation makes LSs aware of the external world.
Distribution Network Reconfiguration Optimization Using a New Algorithm Hyperbolic Tangent Particle Swarm Optimization (HT-PSO)
Authors: Puma David W. , Molina Y. P. , Atoccsa Brayan A. , Luyo J. E. , Ñaupari Zocimo
Published: August 2024

This paper introduces an innovative approach to address the distribution network reconfiguration (DNR) challenge, aiming to reduce power loss through an advanced hyperbolic tangent particle swarm optimization (HT-PSO) method. This approach is distinguished by the adoption of a novel hyperbolic tangent function, which effectively limits the rate of change values, offering a significant improvement over traditional sigmoid function-based methods. A key feature of this new approach is the integration of a tunable parameter, δ, into the HT-PSO, enhancing the curve’s adaptability. The careful optimization of δ ensures superior control over the rate of change across the entire operational range. This enhanced control mechanism substantially improves the efficiency of the search and convergence processes in DNR. Comparative simulations conducted on 33- and 94-bus systems show an improvement in convergence, demonstrating a more exhaustive exploration of the search space than existing methods documented in the literature based on PSO and variations where functions are proposed for the rate of change of values.
An On-Line Sensor Fault Detection System for an AC Microgrid Secondary Control Based on a Sliding Mode Observer Model
Authors: Bravo John , Ortiz Leony , García Edwin , Ruiz Milton , Aguila Alexander
Published: August 2024

The current study proposes a strategy for sensing fault detection in the secondary control of an isolated Microgrid based on a high-order Sliding Mode Robust Observers design. The proposed strategy’s main objective is to support future diagnostic and fault tolerance systems in handling these extreme situations. The proposal is based on a generation system and a waste management system. Four test scenarios were generated in a typical Microgrid to validate the designed strategy, including two Battery Energy Storage Systems in parallel, linear, and non-linear loads. The scenarios included normal grid operation and three types of sensing faults (abrupt, incipient, and random) directly affecting the secondary control of a hierarchical control strategy. The results showed that the proposed strategy could provide a real-time decision for detection and reduce the occurrence of false alarms in this process. The effectiveness of the fault detection strategy was verified and tested by digital simulation in Matlab/Simulink R2023b.
Impact of Energy-Related Properties of Cities on Optimal Urban Energy System Design
Authors: Bertilsson Joel , Göransson Lisa , Johnsson Filip
Published: August 2024

This study investigates how differences in energy-related properties of cities influence the composition of a cost-efficient urban energy system, assuming electrification of the transport and industry sectors and zero-emission of CO2. These differences are evaluated for two scenarios regarding the capacities of the modeled cities to import electricity. A linear optimization model that encompasses the electricity, heating, industry, and transport sectors, using measured data from six cities in Sweden, is applied. Results show that when strict constraints on electricity imports are enforced, cities with a lower ratio of annual electricity demand for heat encourage the implementation of power-to-heat solutions in the heating sector. This study also reveals that under such stringent electricity import conditions, cities with a high level of flexibility in electricity demand favor a combination of batteries and solar photovoltaics as opposed to biomass-based electricity production. Conversely, when electricity importation is less restricted and biomass prices surpass 20 EUR/MWh, local electricity generation is outcompeted by imports, and large-scale heat pumps working in tandem with thermal energy storage dominate the heating sector in all modeled cities. This assertion holds true when the maximum electricity import capacity is utilized up to 5000 h annually.
Data Acquisition of Logging While Drilling at the Newly Discovered Gas Hydrate Reservoir in Hyuganada Sea, Japan
Authors: Imai Toshinori , Aung Than Tin , Fujimoto Akira , Ohtsuki Satoshi , Tano Kotaro , Otomo Shuhei , Shimoda Naoyuki , Yoshii Takanao , Sakata Ryugen , Yoneda Jun , Suzuki Kiyofumi
Published: August 2024

From December 2021 to January 2022, MH21-S conducted an exploratory drilling campaign using logging-while-drilling tools to confirm the methane hydrate concentrated zone (MHCZ) for future offshore production tests. In a preliminary screening study using seismic survey data, methane hydrate (MH) prospects have been extracted in The Hyuganada Sea, offshore Kyushu. In the exploration drilling site, a previous study had reported that MH prospects were inferred from four indices. We have selected two MH prospects: one with an anticlinal structure and another with a planus structure. As a result of drilling, a resistivity value higher than 3 Ω·m, which was a criterion for interpreting MHCZs from log data, was confirmed at a depth of 336–376 mBSF in the prospect with an anticlinal structure. The MH saturation calculated using Archie’s formula was 12–95% (average saturation of 70%). The average density porosity at the same depth was 52%. P-wave velocities were faster than the upper layers. Compared with those of the MHCZ at Daini Atsumi Knoll, the MH saturation is expected to be higher, the spread of some strong-amplitude reflectors has been interpreted from seismic survey data, and the potential MH resources in this area can be sufficiently expected.
Environmental Benefits of the West-East Natural Gas Transmission Project: Cross-Regional Energy Optimization and Transformation for Sustainable Development
Authors: Qian Jiaorong , Han Xuze , Ye Mao , Lv Yexin , Che Jing
Published: August 2024

As a key project of China’s western development, the West-East Natural Gas Transmission Project (WENGT) has effectively alleviated China’s uneven energy distribution and supply-demand issues. It has promoted the optimization of China’s energy structure and sustainable development in the new era, helping to achieve the goal of “double carbon”. Based on pollution data from Chinese industrial enterprises from 2000 to 2012, this paper analyzes the impact of the West-East Natural Gas Pipeline Project on the air pollution emissions of industrial enterprises using a difference-in-difference model and explores the moderating role of local government environmental regulations. The findings indicate that the project significantly reduced air pollutant emissions from industrial enterprises in cities along the route, with a more pronounced reduction effect in areas with higher environmental regulation intensity. Additionally, the emission reduction effect varied among different types of enterprises and regions, with private enterprises showing the smallest reduction impact and the eastern coastal region exhibiting the most significant effect. This paper delves into the relationship between sustainable cross-regional energy development and air pollution emissions from industrial enterprises, providing a theoretical basis for energy conservation and emission reduction policies in China.
Photovoltaics Energy Potential in the Largest Greek Cities: Atmospheric and Urban Fabric Effects, Climatic Trends Influences and Socio-Economic Benefits
Authors: Vigkos Stavros , Kosmopoulos Panagiotis G.
Published: August 2024

This comprehensive study explores the influence of aerosols and clouds on solar radiation in the urban environments of nine of Greece’s largest cities over the decade from 2014 to 2023. Utilizing a combination of Earth Observation data, radiative transfer models, and geographic information systems, the research undertook digital surface modeling and photovoltaic simulations. The study meticulously calculated the optimal rooftop areas for photovoltaic installation in these cities, contributing significantly to their energy adequacy and achieving a balance between daily electricity production and demand. Moreover, the research provides an in-depth analysis of energy and economic losses, while also highlighting the environmental benefits. These include a reduction in pollutant emissions and a decrease in the carbon footprint, aligning with the global shift towards local energy security and the transformation of urban areas into green, smart cities. The innovative methodology of this study, which leverages open access data, sets a strong foundation for future research in this field. It opens up possibilities for similar studies and has the potential to contribute to the creation of an updated, comprehensive solar potential map for continental Greece. This could be instrumental in climate change mitigation and adaptation strategies, thereby promoting sustainable urban development and environmental preservation.
Status, Challenges and Future Directions in the Evaluation of Net-Zero Energy Building Retrofits: A Bibliometrics-Based Systematic Review
Authors: Xiaoxiang Qin , Junjia Yin , Haron Nuzul Azam , Alias Aidi Hizami , Law Teik Hua , Abu Bakar Nabilah
Published: August 2024

Net-zero energy building (NZEB), an initiative to address energy conservation and emission reduction, has received widespread attention worldwide. This study aims to systematically explore recent challenges in NZEB retrofit research through a mixed-method approach and provide recommendations and future directions. A review of 106 documents (2020–2024) retrieved from the Web of Science and Scopus databases found that the globalization of NZEB retrofit research is unstoppable. Assessment methods are diverse, ranging from modeling energy efficiency (using different software such as DesignBuilder 7.0, PVsyst 7.4, EnergyPlus 24.1.0, etc.) to multi-attribute decision-making methods (e.g., DEMATEL-AHP/ANP-VIKOR) and comparative analysis. Current assessment metrics are dominated by economic benefits (e.g., net present value, dynamic payback period, and total operating cost) and energy consumption (e.g., electricity consumption and generation), with less consideration of environmental impacts (e.g., carbon reduction), as well as comfort (e.g., thermal comfort and indoor comfort). The study found that current challenges mainly include “Low economic feasibility of retrofitting”, “Building retrofit energy code irrationality”, and “Insufficient understanding, communication, and trust between stakeholders”. To overcome these challenges, the study also proposes a framework of strategies to address them, including (1) maximizing natural space, (2) introducing a tenant equity system, (3) upgrading waste management, (4) strengthening energy monitoring, (5) establishing complete life cycle mechanisms, (6) providing systemic solutions; (7) promoting the use of low-carbon building materials, and (8) increasing policy support.
Turbulent Boundary Layer Control with Multi-Scale Riblet Design
Authors: Zani Md. Rafsan , Maor Nir Saar , Bhamitipadi Suresh Dhanush , Jin Yaqing
Published: August 2024

Motivated by the saturation of drag reduction effectiveness at high non-dimensional riblet spacing in turbulent boundary layer flows, this study seeks to investigate the influence of a secondary blade riblet structure on flow statistics and friction drag reduction effectiveness in comparison to the widely explored single-scale blade riblet surface. The turbulent flow dynamics and drag reduction performance over single- and multi-scale blade riblet surfaces were experimentally examined in a flow visualization channel across various non-dimensional riblet spacings. The shear velocity was quantified by the streamwise velocity distributions from the logarithmic layer via planar Particle Image Velocimetry (PIV) measurements, whereas the near-wall flow dynamics were characterized by a Micro Particle Image Velocimetry (micro-PIV) system. The results highlighted that although both riblet surfaces exhibited similar drag reduction performances at low non-dimensional riblet spacings, the presence of a secondary riblet blade structure can effectively extend the drag reduction region with the non-dimensional riblet spacing up to 32 and achieve approximately 10% lower friction drag in comparison to the single-scale riblet surface when the non-dimensional riblet spacing increases to 44.2. The average number of uniform momentum zones (UMZs) on the multi-scaled blade riblet has also reduced by 9% compared to the single-scaled riblet which indicates the reduction of strong shear layers within a turbulent boundary layer. The inspection of near-wall flow statistics demonstrated that at high non-dimensional riblet spacings, the multi-scale riblet surface produces reduced wall-normal velocity fluctuations and Reynolds shear stresses. Quadrant analysis revealed that this design allows for the suppression of both the sweep and ejection events. This experimental result demonstrated that surfaces with spanwise variations of riblet heights have the potential to maintain drag reduction effectiveness across a wider range of flow speeds.
Comparative Analysis of Deep Learning Models for Optimal EEG-Based Real-Time Servo Motor Control
Authors: Angelakis Dimitris , Ventouras Errikos C. , Kostopoulos Spiros , Asvestas Pantelis
Published: August 2024

This study harnesses EEG signals to enable the real-time control of servo motors, utilizing the OpenBCI Community Dataset to identify and assess brainwave patterns related to motor imagery tasks. Specifically, the dataset includes EEG data from 52 subjects, capturing electrical brain activity while participants imagined executing specific motor tasks. Each participant underwent multiple trials for each motor imagery task, ensuring a diverse and comprehensive dataset for model training and evaluation. A deep neural network model comprising convolutional and bidirectional long short-term memory (LSTM) layers was developed and trained using k-fold cross-validation, achieving a notable accuracy of 98%. The model’s performance was further compared against recurrent neural networks (RNNs), multilayer perceptrons (MLPs), and Τransformer algorithms, demonstrating that the CNN-LSTM model provided the best performance due to its effective capture of both spatial and temporal features. The model was deployed on a Python script interfacing with an Arduino board, enabling communication with two servo motors. The Python script predicts actions from preprocessed EEG data to control the servo motors in real-time. Real-time performance metrics, including classification reports and confusion matrices, demonstrate the seamless integration of the LSTM model with the Arduino board for precise and responsive control. An Arduino program was implemented to receive commands from the Python script via serial communication and control the servo motors, enabling accurate and responsive control based on EEG predictions. Overall, this study presents a comprehensive approach that combines machine learning, real-time implementation, and hardware interfacing to enable the precise and real-time control of servo motors using EEG signals, with potential applications in the human–robot interaction and assistive technology domains.
Applying Specific Habitat Indicators to Study Asteraceae Species Diversity Patterns in Mountainous Area of Beijing, China
Authors: Zhang Lin , Qi Shi , Zhao Tianheng , Li Peng , Wang Xiangyu
Published: August 2024

The distribution pattern and influencing factors of specific species diversity play a crucial role in decision-making for biodiversity conservation. Identifying suitable regional habitat indicators to assess specific species diversity patterns is a global focus topic. A total of 112 sample plots were surveyed to investigate the relationship between Asteraceae species diversity and topography, soil nutrients, and stand factors, using a Structural Equation Model (SEM). Additionally, the Maxent model was utilized to predict the distribution pattern of Asteraceae species diversity in response to specific habitat factors. The findings revealed that soil nutrients, topography, and canopy closure had different impacts on Asteraceae species diversity, with soil nutrients showing the highest relative coefficient, followed by topography and canopy closure. The elevation and slope gradient were identified as direct and indirect influences on Asteraceae species diversity. The contribution rate of potential environmental variables on the Asteraceae species diversity was ranked as follows: STN (29.7%) > SOM (28.5%) > slope (8.5%) > Ele (8.1%). Asteraceae species diversity was found to be abundant in the locations with SOM (>27 g/kg), STN (>1.8 g/kg), Ele (165–333 m), and slopes (5–12 degrees). Soil nutrient content serves as a key indicator for assessing the abundance of Asteraceae species diversity and should be considered in biodiversity conservation.
Safeguarding Local Communities for REDD+ Implementation in Ghana
Authors: Andoh Jewel , Martey Edward , Obeng Elizabeth Asantewaa , Oduro Kwame Antwi , Salimath Pone , Lee Yohan
Published: August 2024

In this study, we primarily assess the relationship between social safeguards and the living standards of local communities in different ecological zones of Ghana, relying on data from the seventh round of the Ghana Living Standard Survey (GLSS 7) and publicly available policy documents from the Ghana Statistical Service and the Forestry Commission of Ghana, respectively. This research aims to assist policymakers and stakeholders to make informed and appropriate decisions when developing social safeguards for emission reduction projects. The GLSS 7 covers 14,009 households, comprising 59,864 individuals in 892 enumeration areas or communities across the 10 regions of Ghana, now divided into 16. The data were collected using a stratified random sampling technique. Principal component analysis was employed to develop a living condition index, after which we generated a second construct based on the number of factors affecting living conditions. The results showed that access to sharecropping, literacy, extension services, financial institutions, a mobile phone network, and markets have significant positive relationships with the living conditions of local communities in Ghana. In addition, 78% of the social safeguards described in Ghana’s REDD+ strategy, Forest and Wildlife Policy, Benefits Sharing Mechanism, and Forest Plantation Development Strategy are aligned with the determinants of local communities’ living conditions. The findings suggest a need to enforce the Benefit Sharing Mechanism, better forest governance, and tenancy reforms in order to prevent the overexploitation of landowners and avoid elite capture. Furthermore, farmers must be linked to financial institutions in order to obtain credits. Additionally, we must seek to provide local communities with better access to markets and mobile phone networks in a way that allows them to carry out their livelihood activities effectively and efficiently. These measures help to reduce the risk of REDD+ actions and ensure sustainability.