bluuebunny/crossref_metadata_2025 huggingface dataset:
Mollusk Thanatocoenoses Unravel the Diversity of Heterogeneous Rhodolith Beds (Italy, Tyrrhenian Sea)
Authors: Bracchi Valentina Alice , Meroni Agostino Niyonkuru , Epis Vivien , Basso Daniela
Published: April 2023

Emerging evidence of rhodolith bed complexity and heterogeneity poses a challenge to monitoring strategies and questions about the role of abiotic factors in controlling the observed morphostructural diversity. Mollusk thanatocoenoses quickly respond to environmental conditions, expressing fidelity to biocoenosis and representing, thus, a useful ecological/paleoecological tool to unravel this heterogeneity. In this research, we studied three distinct rhodolith beds from the Tyrrhenian Sea (Italy), in a range between 40 and 100 m of water depth, together with their mollusk thanatocoenoses, sediment size, and oceanographic conditions. The beds are all heterogeneous and rarely correspond to a specific rhodolith morphotype and shape. On the contrary, the study of the associated thanatocoenoses led to distinguish at least five different assemblages within the known variability of the Coastal detritic (DC) association. DC and deep mud (VP) mollusk species dominate hanatocoenosis A, which is associated with mixed sediment and a low hydrodynamic regime. Thanatocoenosis B corresponds to an assemblage in which DC species mixed with species of adjacent vegetated bottoms in sandy sediment with a medium hydrodynamic. Thanatocoenosis C includes species related to muddy coastal detritic (DE) and offshore detritic (DL) associated with sand and a variable proportion of praline and branch morphotypes. Thanatocoenoses D and E include a wide range of detritic species (DE DC, DL) together with VP and coralligenous (C), associated with exclusive praline and gravelly sand (Thanat. D), or a mixed proportion of branch and praline and mixed sediment (Thanat. E). Our results demonstrate that the study of mollusk thanatocoenoses provides insights into the diversity within and among heterogeneous rhodolith beds. Moreover, rhodoliths, as part of the sediment, create microhabitats suitable for a wide range of mollusk species that contribute to the formation of complex thanatocoenoses.
Survival and Genome Evolution Signatures of Klebsiella pneumoniae Isolates Originated in Seven Species of Aquatic Animals
Authors: Guan Huiqiong , Xie Lu , Chen Lanming
Published: April 2023

Klebsiella pneumoniae can cause life-threatening pneumonia in humans. The bacterium is also the causative agent of nosocomial infection diseases. In our recent research, we reported, for the first time, the presence of K. pneumoniae in fourteen species of aquatic animals sampled in Shanghai, China. Here, we further investigated the bacterial survival and genome evolution traits. The results revealed that K. pneumoniae isolates (n = 7), recovered from 7 species of commonly consumed aquatic animals, had multiple antibiotic and heavy metal resistance profiles. The isolates were capable of growing vigorously at pH 4.5−7.5 and 0.5−1.0% NaCl in TSB medium at 37 °C. Draft genome sequences of the K. pneumoniae isolates were determined (5,256,522−5,857,823 bp, 56.35–57.81% GC contents), which carried many mobile genetic elements, including genomic islands (n = 87), prophages (n = 14), integrons (n = 4), and insertion sequences (n = 22), indicating possible active horizontal gene transfer during the genome evolution. Meanwhile, numerous strain-specific (n = 199−605) genes, antibiotic resistance (n = 20−35, e.g., β-lactamase) genes, and virulence (n = 43−59, e.g., enterobactin)-related genes, were also identified, demonstrating considerable genome variation in the K. pneumoniae isolates. Overall, the results of this study fill prior gaps in understanding the K. pneumoniae genomes derived from aquatic animals.
Benthic Characterization of Mesophotic Communities Based on Optical Depths in the Southern Mexican Pacific Coast (Oaxaca)
Authors: Pérez-Castro Miguel Ángel , Eyal Gal , Leyte-Morales Gerardo Esteban , Hinojosa-Arango Gustavo , Enríquez Susana
Published: April 2023

The distinction between shallow coral reefs and mesophotic coral ecosystems (MCEs) has not been fully clarified yet. The original definition of MCEs, by depths of 30–150 m, fixes their bathymetrical limits and fails to accommodate environmental and biological variation. Recent studies have indicated that water transparency and light availability may explain why MCEs do not occur at fixed depths but vary among localities. This study aimed to evaluate the presence and distribution of MCEs, along the central coast of Oaxaca, through optical depths and the associated benthic community. Using MODIS-Aqua satellite data (Kd490), we estimated the mesophotic optical depths monthly (z10%, z1%, z0.1%), over the last four years. In addition, to characterize benthic community structure, we conducted underwater photo quadrat surveys at two locations on the southern Mexican Pacific coast from 10 to 55 m depth. Significant differences between depths and locations were found in benthic communities. Furthermore, the lower distribution of photosynthetic taxa was different between the two locations but indicative to the z10% and z1% in both cases. Those differences were associated with the upwelling season, which reduces, drastically and differentially, the light availability for benthic communities between the two locations and limits the development of MCEs on the central coast of Oaxaca.
Histologically Confirmed Testicular Metastasis Revealed by [89Zr]Zr-PSMA-617 PET/CT in a Patient with Biochemical Recurrence of Prostate Cancer and Negative Conventional PSMA PET/CT Imaging
Authors: Rosar Florian , Burgard Caroline , Linxweiler Johannes , Wagner Mathias , Ezziddin Samer
Published: April 2023

We present an interesting image of a testicular metastasis from prostate cancer revealed by [89Zr]Zr-PSMA-617 PET/CT imaging in a 70-year-old man with biochemical recurrence and negative conventional [68Ga]Ga-PSMA-11 PET/CT imaging. This case should encourage the consideration of [89Zr]Zr-PSMA-617 PET/CT if conventional PSMA PET/CT imaging had failed to localize biochemical recurrence, and may remind colleagues of this rare but potential metastatic localization in this setting.
Clinical Validation of a Colorimetric Loop-Mediated Isothermal Amplification Using a Portable Device for the Rapid Detection of SARS-CoV-2
Authors: Raddatz Bruna W. , Rabello Felipe J. , Benedetti Rafael , Steil Gisleine J. , Imamura Louise M. , Kim Edson Y. S. , Santiago Erika B. , Hartmann Luís F. , Predebon João V. , Delfino Bruna M. , Nogueira Meri B. , dos Santos Jucélia S. , da Silva Breno G. , Nicollete Diego R. P. , Almeida Bernardo M. M. de , Rogal Sergio R. , Figueredo Marcus V. M.
Published: April 2023

Quick and reliable mass testing of infected people is an effective tool for the contingency of SARS-CoV-2. During the COVID-19 pandemic, Point-of-Care (POC) tests using Loop-Mediated Isothermal Amplification (LAMP) arose as a useful diagnostic tool. LAMP tests are a robust and fast alternative to Polymerase Chain Reaction (PCR), and their isothermal property allows easy incorporation into POC platforms. The main drawback of using colorimetric LAMP is the reported short-term stability of the pre-mixed reagents, as well as the relatively high rate of false-positive results. Also, low-magnitude amplification can produce a subtle color change, making it difficult to discern a positive reaction. This paper presents Hilab Molecular, a portable device that uses the Internet of Things and Artificial Intelligence to pre-analyze colorimetric data. In addition, we established manufacturing procedures to increase the stability of colorimetric RT-LAMP tests. We show that ready-to-use reactions can be stored for up to 120 days at −20 °C. Furthermore, we validated both the Hilab Molecular device and the Hilab RT-LAMP test for SARS-CoV-2 using 581 patient samples without any purification steps. We achieved a sensitivity of 92.93% and specificity of 99.42% (samples with CT ≤ 30) when compared to RT-qPCR.
Prognostic Impact of the Get-with-the-Guidelines Heart-Failure Risk Score (GWTG-HF) after Transcatheter Aortic Valve Replacement in Patients with Low-Flow–Low-Gradient Aortic Valve Stenosis
Authors: Eckel Clemens , Blumenstein Johannes , Husser Oliver , Sötemann Dagmar , Grothusen Christina , Schlüter Judith , Becher Marc , Nef Holger , Elsässer Albrecht , Nickenig Georg , Möllmann Helge , Tiyerili Vedat
Published: April 2023

Objectives: This study examined the prognostic value of the get-with-the-guidelines heart-failure risk score (GWTG-HF) on mortality in patients with low-flow–low-gradient aortic valve stenosis (LFLG-AS) after transcatheter aortic valve implantation (TAVI). Background: Data on feasibility of TAVI and mortality prediction in the LFLG-AS population are scarce. Clinical risk assessment in this particular population is difficult, and a score has not yet been established for this purpose. Methods: A total of 212 heart failure (HF) patients with real LFLG-AS were enrolled. Patients were classified into low-risk (n = 108), intermediate-risk (n = 90) and high-risk (n = 14) groups calculated by the GWTG-HF score. Clinical outcomes of cardiovascular events according to Valve Academic Research Consortium (VARC-2) recommendations and composite endpoint of death and hospitalization for heart failure (HHF) were assessed at discharge and 1 year of follow-up. Results: Baseline parameters of the groups showed a median age of 81.0 years [77.0; 84.0] (79.0 vs. 82.0 vs. 86.0, respectively p < 0.001), median EuroSCORE II of 6.6 [4.3; 10.7] (5.5 vs. 7.2 vs. 9.1, p = 0.004) and median indexed stroke volume of 26.7 mL/m2 [22.0; 31.0] (28.2 vs. 25.8 vs. 25.0, p = 0.004). The groups significantly differed at follow-up in terms of all-cause mortality (10.2 vs. 21.1 vs. 28.6%; p < 0.035). There was no difference in intrahospital event rate (VARC). Postprocedural mean gradients were lower in high-risk group (7.0 vs. 7.0 vs. 5.0 mmHg, p = 0.011). No differences in postprocedural aortic valve area (1.9 vs. 1.7 vs. 1.9 cm2, p = 0.518) or rate of device failure (5.6 vs. 6.8 vs. 7.7%, p = 0.731) could be observed. After adjustment for known predictors, the GWTG score (HR 1.07 [1.01–1.14], p = 0.030) as well as pacemaker implantation (HR 3.97 [1.34–11.75], p = 0.013) turned out to be possible predictors for mortality. An increase in stroke volume index (SVI) was, in contrast, protective (HR 0.90 [0.83–0.97]; p = 0.006). Conclusions: The GWTG score may predict mortality after TAVI in LFLG-AS HF patients. Interestingly, all groups showed similar intrahospital event and mortality rates, independent of calculated mortality risk. Low SVI and new conduction disturbances associated with PPI after THV implantation had negative impact on mid-term outcome in post-TAVI HF-patients.
Prognostic Performance of Bedside Lung Ultrasound Score (LUSS) and ROX Index in Hypoxemic Respiratory Failure Due to COVID-19
Authors: Nova Alice , Rezoagli Emanuele , Eronia Nilde , Benini Annalisa , Scognamiglio Andrea , Foti Giuseppe , Bellani Giacomo
Published: April 2023

Background: Noninvasive ventilation, mainly helmet CPAP, was widely used during the COVID-19 pandemic, even outside of intensive care units. Both the ROX index and the LUS score (LUSS) have been proposed as tools to predict negative outcomes in patients with hypoxemia treated with noninvasive ventilation (NIV) outside of ICUs. We aim to evaluate whether the combination of LUSS with the ROX index improves the predictive performance of these indices in patients with hypoxemia due to COVID-19 pneumonia, treated with NIV outside of ICUs. Methods: This is a monocentric prospective observational study conducted at the university teaching hospital Fondazione IRCCS San Gerardo dei Tintori (Monza, Italy) from February to April 2021. LUSS and ROX were collected at the same time in noninvasively ventilated patients outside of the ICU. An LUS exam was performed by 3 emergency medicine attending physicians with at least 5 years’ experience in point-of-care ultrasonography using a 12-zone system. To evaluate the accuracy of the prognostic indices in predicting a composite outcome (endotracheal intubation and mortality), ROC curves were used. A logistic multivariable model was used to explore the predictors of the composite outcome of endotracheal intubation and in-hospital mortality. An unadjusted Kaplan–Meier analysis was used to explore the association with the composite outcome of survival without invasive mechanical ventilation at the 30-day follow-up by stratifying the 3 indices by their best cut-offs. Results: A total of 79 patients were included in the statistical analysis and stratified into 2 groups based on the presence of a negative outcome, which was reported in 24 patients out of 79 (30%). A great proportion of patients (66 patients—84%) were treated with helmet CPAP. All three indices (LUSS, ROX and LUSS/ROX) were independently associated with negative outcomes in the multivariable analyses. Although the comparison between the AUROC of LUSS or ROX versus LUSS/ROX did not reveal a statistically significant difference, we observed a trend toward a higher accuracy for predicting negative outcomes using the LUSS/ROX index as compared to using LUSS. With the Kaplan–Maier approach, all three indices stratified by the best cut-off reported a significant association with the outcome of 30-day survival without mechanical ventilation. Conclusions: A multimodal noninvasive approach that combines ultrasound (i.e., LUSS) and a bedside clinical evaluation (i.e., the ROX index) may help clinicians to predict outcomes and to identify patients who would benefit the most from invasive respiratory support.
Patient Reported Outcome Measures (PROMs) in Surgery: Evaluation after Minimally Invasive Reduction and Percutaneous K-Wires Fixation for Intra-Articular Calcaneal Fractures
Authors: Brognara Lorenzo , Mazzotti Antonio , Arceri Alberto , Artioli Elena , Casadei Giacomo , Bonelli Simone , Traina Francesco , Faldini Cesare
Published: April 2023

Background: The optimal surgical treatment of intra-articular calcaneal fractures (IACF) is still under debate. In the literature, results are based on clinical or radiographical findings. Few studies have evaluated the effect of patient expectations on patient-reported outcomes after surgery and little is known about outcomes directly reported by the patient who experienced it. Patient reported outcome measures (PROMs) may represent a viable and useful tool for evaluating the efficacy of the procedure and can be considered as an indicators of health-care quality. The aim of this study is to evaluate PROMs after minimally invasive reduction and percutaneous Kirschner-wires fixation for IACF, and to compare PROMs to pre-operative and last follow-up radiographic findings. Methods: 33 consecutive patients with IACF treated with minimally invasive reduction and percutaneous K-wires fixation were included. Data collection included demographics, pre-operative and last available Böhler and Gissane angle X-rays, foot function index (FFI), and foot and ankle outcome score (FAOS). Results: At a mean follow up of 36.7 months, the mean FFI score was 24.3 ± 19.9 and the mean FAOS score was 68 ± 24.8. Patients with better Gissane angle showed better activity limitations FFI subscores. Moreover, worse pre-operative Gissane and Böhler angle were significantly associated with a worse total FAOS score and subscores. Conclusions: Minimally invasive reduction and percutaneous K-wires fixation provided satisfactory PROMs. Despite these results, prospective randomized studies are required to confirm the validity and reliability of PROMs in evaluating different treatments.
Sharia Economy, Islamic Financial Performance and Factors That Influence It—Evidence from Indonesia
Authors: Menne Firman , Mardjuni Sukmawati , Yusuf Muhammad , Ruslan Muhlis , Arifuddin A. , Iskandar Iskandar
Published: April 2023

The contribution of SMEs to economic growth is supported by the development of the sharia economy by the government, making SMEs one of the main pillars in Indonesia’s economic development. This study aimed to analyze the influence of the digital economy, financial literacy, human capital, the role of Islamic financial institutions, government support for strengthening the Islamic economy and the Islamic financial performance of SMEs in Makassar City, Indonesia. This study used a quantitative method with a survey approach. Data were obtained through questionnaires distributed to 350 respondents with a sampling method. The results of this study indicated that the strengthening of the sharia economy, the Islamic financial performance of SMEs, economic digitalization and financial literacy are determined by factors of human capital, the role of Islamic financial institutions and government support. Regarding human capital, the roles of Islamic financial institutions and government support affect the Islamic financial performance of SMEs with a coefficient of determination of 58.5%. Human capital, the role of Islamic financial institutions, government support and financial performance have a positive correlation with the strengthening of the sharia economy with a coefficient of determination of 71.6%. This study supports the improvement of government policies and the construction of financial facilities in improving the Islamic financial performance of SMEs and encourages the strengthening of the sharia economy in Makassar City, South Sulawesi, Indonesia. The limitation of this research is that the research object was only carried out on SMEs in Makassar City; thus, similar research can be increased at the national level to describe the strengthening of the sharia economy and the improvement of the financial performance of SMEs as a whole in Indonesia.
Smartphones and Learning: Evaluating the Focus of Recent Research
Authors: Hartley Kendall , Hoffman Bobby , Andújar Alberto
Published: April 2023

The smartphone has become integral to most aspects of students’ lives and is the primary conduit for accessing the internet. Objective research into the promise and dangers of this device is critical. While educational uses of the smartphone with young adults hold promise, the potential for harm is also present. While objectivity is valued, the focus of researchers can subjectively skew towards optimistic or pessimistic views of technology. The topics addressed in smartphone and learning research illuminate trends and potential biases in the field. This study investigates the issues addressed in smartphone and learning research in the past two years. These topics are compared with smartphone research in a similar field: psychology. The study, using a bibliometric approach, identified an overall negative arc of the literature towards topics such as addiction, depression, and anxiety in the psychology literature. The educational literature topics were comparatively more positive than psychology. Highly cited papers in both fields reflected explorations of adverse outcomes.
Fault Segment Location for MV Distribution System Based on the Characteristic Voltage of LV Side
Authors: Zhang Dehai , Zhang Wenhai , Wang Changzhi , Xiao Xianyong
Published: April 2023

The voltage and current measurement of the medium-voltage (MV) side are used for the traditional fault location method, which leads to a high installation cost of the measurement and complicated post-operational and maintenance work. A fault location method is proposed based on the distributed measurement at the low-voltage (LV) side. On the analysis of voltage distribution rules and the influence of the distribution transformer on voltage transmission, obvious differences are found in the variation of voltage (phase voltage and sequence voltage) at the LV side for different faults—specifically, the detection sensitivity of the voltage to different faults varies. Therefore, a fault location method for the MV distribution network based on characteristic voltage at the LV side is proposed. Firstly, the characteristic voltage is selected adaptively according to the fault type. The suspected fault path is then determined by the characteristic voltage amplitude of measuring points. Finally, the fault segment is located via the characteristic current of each segment. This method can be applied in combination with the widely used LV measurement equipment such as the power consumption information acquisition system and the intelligent fusion terminal to acquire LV side voltage without adding new measurement devices. The distribution difference of the characteristic voltage at the LV side is applied for accurate fault finding, which is an economical and practical new idea for the fault location of the distribution network. The correctness and effectiveness of the method were verified by the simulation of the IEEE 34 system built in PSCAD/EMTDC and a real distribution network.
Summarization of Videos with the Signature Transform
Authors: de Curtò J. , de Zarzà I. , Roig Gemma , Calafate Carlos T.
Published: April 2023

This manuscript presents a new benchmark for assessing the quality of visual summaries without the need for human annotators. It is based on the Signature Transform, specifically focusing on the RMSE and the MAE Signature and Log-Signature metrics, and builds upon the assumption that uniform random sampling can offer accurate summarization capabilities. We provide a new dataset comprising videos from Youtube and their corresponding automatic audio transcriptions. Firstly, we introduce a preliminary baseline for automatic video summarization, which has at its core a Vision Transformer, an image–text model pre-trained with Contrastive Language–Image Pre-training (CLIP), as well as a module of object detection. Following that, we propose an accurate technique grounded in the harmonic components captured by the Signature Transform, which delivers compelling accuracy. The analytical measures are extensively evaluated, and we conclude that they strongly correlate with the notion of a good summary.
Long Distance Military Fiber-Optic Polarization Sensor Improved by an Optical Amplifier
Authors: Kyselak Martin , Vavra Jiri , Slavicek Karel , Grenar David , Hudcova Lucie
Published: April 2023

The ever-increasing demands for the use of fiber-optic sensors powered by long optical fibers is forcing developers to solve problems associated with powering these remote sensors. Due to their non-electric character, these sensors are suitable for many uses, including military applications. The Army of the Czech Republic is very interested in this type of optical fiber sensor as it fulfils the significant prerequisites for use in military areas. However, the army’s requirements are challenging because they require long supply cables in which there is significant attenuation of optical power. At the same time, there is a need for high sensitivity. The subject of our research team’s work was to use amplifiers to power these sensors. The army already uses this type of sensor for short distances as it cannot ignite a gas mixture with an explosive concentration and thus meet the strict requirements of the explosion-poof standard. The novelty of our research lies in the discovered measurement technique that allows the sensors to be powered remotely and in the saving of optical fibers by utilizing duplex communication with a circulator. Furthermore, the research presents an innovative approach to the optimization of the entire sensor by using a bidirectional, sensory, polarization-maintaining optical fiber. The proposed sensor was first verified in laboratory conditions at the Optoelectronics Laboratory of the University of Defense in Brno, and further tests were carried out in the military training areas of Boletice and Březina in the Czech Republic, which is a member of North Atlantic Treaty Organization.
DNCL: Hybrid DOA Estimation and NMDS Cooperative Multi-Target Localization for RFID
Authors: Li Yuting , Ma Yongtao , Tian Chenglong , Su Dianfei , Yang Bo
Published: April 2023

Passive radio frequency identification (RFID) tags have been widely used in logistics, supply chain, warehousing, and other fields. However, for RFID-based automatic inventory management in warehouses, the deployment of current methods is more complex, and the localization range still has some limitations. This paper proposes DNCL, which is a hybrid passive RFID localization scheme based on direction-of-arrival (DOA) estimation and nonmetric multidimensional scaling (NMDS) to achieve spatial coordinate localization of tagged objects on shelves or racks using a single antenna for simple 1D scanning. DNCL uses antenna dynamic scanning to generate a virtual antenna array for the dynamic information capture of tags in the scene, which helps eliminate the phase shift produced by ambient noise. We apply the angle profile linear model to identify the characteristics of each tag and introduce the NMDS algorithm to improve the robustness of the scheme through the fixed layout of the reference tags, which can reliably estimate the coordinates of the tagged objects in the space. This paper realizes a prototype system and validated its practical performance in real complex situationse by COTS RFID devices. The results indicate that DNCL can achieve high accuracy for the localization of passive tags in free space.
Survivability Analysis of Unmanned Aerial Vehicle Network based on Dynamic Weighted Clustering Algorithm with Dual Cluster Heads
Authors: Zhang Yujing , Hu Zhiqun , Wang Zhifei , Wen Xiangming , Lu Zhaoming
Published: April 2023

The unmanned aerial vehicles (UAVs) network is vulnerable due to the high mobility and energy-constrained characteristics of UAVs. Nonetheless, as a UAV-based communication network, a stable network topology is crucial for efficient communication. To this end, in this paper, we propose a dynamic weighted clustering algorithm with dual cluster heads (DWCA-DCH) in this paper to deploy the UAV network. To trade off communication efficiency and lifetime, the selection of prime and backup cluster heads is designed by synthetically considering communication quality and remaining energy of the UAV. Furthermore, a survivability analysis method based on Markov process (SAM-MP) is constructed to analyze the survivability performance of the proposed UAV network based on DWCA-DCH when the UAV node suffers from energy exhausting or accidents. The simulation results show that the survivability and stability of the UAV cluster ad hoc network based on DWCA-DCH proposed in this paper is improved by about 35% compared with the single cluster head network.
Anaerobic Digestion of Olive Mill Wastewater in the Presence of Biochar
Authors: Micoli Luca , Di Rauso Simeone Giuseppe , Turco Maria , Toscano Giuseppe , Rao Maria A.
Published: April 2023

Biological treatments focused on stabilizing and detoxifying olive mill wastewater facilitate agronomic reuse for irrigation and fertilization. Anaerobic digestion is particularly attractive in view of energy recovery, but is severely hampered by the microbial toxicity of olive mill wastewater. In this work, the addition of biochar to the digestion mixture was studied to improve the stability and efficiency of the anaerobic process. Kinetics and yields of biogas production were evaluated in batch digestion tests with biochar concentrations ranging from 0 to 45 g L−1. The addition of biochar reduced sensibly the lag phase for methanogenesis and increased the maximum rate of biogas generation. Final yields of hydrogen and methane were not affected. Upon addition of biochar, soluble COD removal increased from 66% up to 84%, and phenolics removal increased from 50% up to 95%. Digestate phytotoxicity, as measured by seed germination tests, was reduced compared to raw wastewater. Addition of biochar further reduced phytotoxicity and, furthermore, a stimulatory effect was observed for a twenty-fold dilution. In conclusion, biochar addition enhances the anaerobic digestion of olive mill wastewaters by effectively reducing methanogenesis inhibition and digestate phytotoxicity, thus improving energy and biomass recovery.
Microstructure of Surface Pollutants and Brush-Based Dry Cleaning of a Trough Concentrating Solar Power Station
Authors: Wang Chenyang , Guo Jialin , Li Jingyu , Zeng Xiaomei , Pelenovich Vasiliy , Zhang Jun , Yang Bing , Wang Xianbin , Du Yu , Lei Yikun , Lu Naibing
Published: April 2023

The accumulation of pollutants on the surface of a Concentrating Solar Power (CSP) station reduces the power generation efficiency of the whole power plant, affects electricity output, and decreases sales income; therefore, it is particularly important to develop a reasonable and effective cleaning process. Surface pollutants which have a strong interaction with the cleaning process of power stations can determine the quality of cleaning to a certain extent. In this paper, the pollutants on the surface of a trough CSP station with different usage times were collected and characterized using a scanning electron microscope (SEM), a particle size analyzer (PSA), and a transmission electron microscope (TEM). It was found that most of the surface pollutants were of a fine size and included amorphous particles which mainly resulted from the sedimentation of particles suspended for a short time or particles in the process of atmospheric circulation for a long time. Considering the service life of the mirror and the scarcity of water resources in the area where the trough CSP power station is located, a brush-based dry cleaning process with different cleaning times was developed. By comparing the changes in the reflectivity and micro-morphology of the mirror surface before and after cleaning, the feasibility and superiority of the brush-based dry cleaning process were fully confirmed.
Modelling Electroluminescence Emission in Polymeric Material Using Dimensional Analysis Method
Authors: Bani Nurul Aini , Muhammad-Sukki Firdaus , Mas’ud Abdullahi Abubakar , Muhtazaruddin Mohd Nabil , Abu-Bakar Siti Hawa , Rahmat Mohd Khairil , Musa Umar , Rohani Mohamad Nur Khairul Hafizi , Agyeman Michael Opoku
Published: April 2023

The Electroluminescence (EL) technique has garnered significant interest over time for its reliable outcomes that enrich our understanding of the onset of electrical degradation in polymeric material. There is growing interest in combining both the EL technique and space charge measurement methods to obtain a more profound knowledge of the degradation and ageing of insulation. The generation of charge carriers in polymeric materials is widely acknowledged to be a crucial aspect of EL, involving injection, de-trapping, and field dissociation processes. This research investigates the variables that influence how EL emissions behave, including applied voltage or electric field, applied electrical frequency, ageing of material, and selection of materials and gases employed. It was found that these factors can be helpful in predicting the process of electrical ageing in insulation to avoid any catastrophes that may occur. A mathematical approach relating these factors and the intensity of EL is proposed through the aid of Dimensional Analysis method. A close relationship is obtained that suggests this mathematical approach can be utilised as a tool to predict electrical ageing of insulation material.
Characteristic Evaluation of Different Carbonization Processes for Hydrochar, Torrefied Char, and Biochar Produced from Cattle Manure
Authors: Song Eunhye , Kim Ho , Kim Kyung Woo , Yoon Young-Man
Published: April 2023

The amount of cattle manure generated accounts for over 40% of the livestock manure in South Korea. Most livestock manure is utilized as a fertilizer and a soil amendment. However, the soil nutrients have exceeded saturation in South Korea. Accordingly, cattle manure, including lignocellulosic biomass, was applied for solid fuel production in this study. The three different types of carbonization process, namely, hydrothermal carbonization, torrefaction, and carbonization (slow pyrolysis), were estimated for a comparison of the hydrochar, torrefied char, and biochar characteristics derived from cattle manure. The processes were performed at temperatures ranging from 190 to 450 °C. The evaluation of the hydrochar, torrefied char, and biochar produced by three processes was conducted by the proximate, ultimate, calorific value, fuel ratio, and energy yield, which were used for the analysis of fuel quality. Additionally, the ash properties, including silicon dioxide, chlorine, and base-to-acid ratio (B/A) on hydrochar, torrefied char, and biochar were investigated to predict ash deposition during combustion. These analyses are essential to stabilize the operation of the combustion chamber. The thermogravimetric analysis represented the upgraded quality of hydrochar, torrefied char, and biochar by three different carbonization processes.
Optimal Design of Double Stage Internal Loop Air-Lift Bioreactor
Authors: Ramonet Fernando , Haddadi Bahram , Harasek Michael
Published: April 2023

Biorefinery systems play a critical role in the transition towards a sustainable bioeconomy, and bioreactors are a key component in these systems. While mechanically stirred reactors have been extensively studied, there is a lack of research on pneumatically driven systems like air-lift reactors (ALRs). This study aims to address this gap by examining the hydrodynamic behavior of a double draft tube airlift bioreactor using Computational fluid dynamics simulations. Ten different geometric configurations were investigated, with variations in draft tube placement, liquid height, distance between draft tubes and draft tube diameters. Results showed that the placement of the draft tubes heavily influenced hydrodynamic behavior, with smaller distances between draft tubes and a funnel configuration leading to higher velocities. Stable downcomer velocities were achieved by maintaining a consistent distance between the bottom clearance and the sum of the distance between draft tubes and the bottom clearance on the top clearance. The model was validated against literature experimental data. This study provides insight into the optimal design of ALRs, which can contribute to the development of more efficient and effective bioreactor systems. The findings can be used to forecast the most optimal configurations of airlift bioreactors and have significant value for the development of more efficient biorefining concepts in light of the increasing importance of studying biorefineries and their components in the shift towards a biomass-based economy.
Fast Well Control Optimization with Two-Stage Proxy Modeling
Authors: Ng Cuthbert Shang Wui , Jahanbani Ghahfarokhi Ashkan , Wiranda Wilson
Published: April 2023

Waterflooding is one of the methods used for increased hydrocarbon production. Waterflooding optimization can be computationally prohibitive if the reservoir model or the optimization problem is complex. Hence, proxy modeling can yield a faster solution than numerical reservoir simulation. This fast solution provides insights to better formulate field development plans. Due to technological advancements, machine learning increasingly contributes to the designing and building of proxy models. Thus, in this work, we have proposed the application of the two-stage proxy modeling, namely global and local components, to generate useful insights. We have established global proxy models and coupled them with optimization algorithms to produce a new database. In this paper, the machine learning technique used is a multilayer perceptron. The optimization algorithms comprise the Genetic Algorithm and the Particle Swarm Optimization. We then implemented the newly generated database to build local proxy models to yield solutions that are close to the “ground truth”. The results obtained demonstrate that conducting global and local proxy modeling can produce results with acceptable accuracy. For the optimized rate profiles, the R2 metric overall exceeds 0.96. The range of Absolute Percentage Error of the local proxy models generally reduces to 0–3% as compared to the global proxy models which has a 0–5% error range. We achieved a reduction in computational time by six times as compared with optimization by only using a numerical reservoir simulator.
Review of Methods to Create Meteorological Data Suitable for Moisture Control Design by Hygrothermal Building Envelope Simulation
Authors: Kim Sughwan , Zirkelbach Daniel , Künzel Hartwig M.
Published: April 2023

Hygrothermal simulations have become essential for sustainable and resilient building design because moisture is the major cause of problems in buildings. Appropriate meteorological input data are important to obtain meaningful simulation results. Therefore, this article reviews different methods to create Hygrothermal Reference Years (HRY) as severe or average climate inputs. The current standards define HRYs solely based on outdoor temperature, although moisture problems are caused by a combination of climate parameters, including driving rain and other loads. Therefore, there are also methods considering several impact parameters. The existing methods can be classified into two categories: construction-independent and construction-dependent methods. The former determines HRY based on a weather data analysis and is useful for large-scale parametric studies comprising many climatic parameters acting on buildings. The latter is based in addition to computer simulations to verify the HRY also in the context of specific construction types. It is a more comprehensive approach since the moisture responses of constructions are the decisive outcome for performance predictions. The advantages and disadvantages of the different methods are summarized and compared. Lastly, further research questions and simplifications aimed at practitioners are pointed out to arrive at reliable hygrothermal building performance predictions.
P-Y Curve Correction of Shallow Seabed Formation Containing Hydrate
Authors: Diao Haoyu , Fan Honghai , Ji Rongyi , Wu Bangchen , Ye Yuguang , Liu Yuhan , Zhou Fei , Yang Yixiang , Yan Zhi
Published: April 2023

With the continuous growth in global energy demand, the exploration and development of hydrates has been the focus of increasing attention, and the accurate evaluation of the mechanical properties of hydrate layers has become particularly important. In this study, using a self-developed hydrate sample preparation device and hydrate triaxial seepage test platform, triaxial shear tests were carried out using the in situ synthesis method for hydrate sediment in the laboratory, and the stress–strain curves of hydrate sediment with different levels of saturation were obtained. By analyzing the stress–strain curve, the mechanical parameters of hydrate sediment were calculated and simulated using ABAQUS (2021, Dassault systemes, Vélizy Villacoublay France) finite element software. Several p-y curves were calculated and compared with the simulation results, and the p-y curve correction method of the hydrate layer in a shallow seabed was obtained. It was found that the strength of the hydrate sediment increased with an increase in saturation. At the same time, an increase in confining pressure and a decrease in temperature also increased the strength of hydrate deposits. Through comparison with the existing API (American Petroleum Institute) standard p-y curve, it was found that its strength is low because the existence of the hydrate improves the formation strength.
Synergistic Germanium-Decorated h-BN/MoS2 Heterostructure Nanosheets: An Advanced Electrocatalyst for Energy Storage Applications
Authors: Saravanan M. , Palanisamy Rajkumar , Sethuraman V. , Diwakar K. , Kumar P. Senthil , Venkatesh P. Sundara , Kannan N. , Kingston R. Joel , Aravinth K. , Kim Jinho
Published: April 2023

Increasing concerns about the vulnerability of the world’s energy supply and the necessity to implement sustainable technologies have prompted researchers to develop high-performance electrocatalysts that are affordable and efficient for converting and storing renewable energy. This article reports a facile approach to fabricating two-dimensional (2D) Ge-decorated h-BN/MoS2 heterostructure nanosheets by self-assembly for multiple electrochemical applications such as supercapacitor and hydrogen evolution reactions. The organization of the physical and chemical links between the germanium modulations on the heterostructure of boron nitride/molybdenum sulphide (Ge/h-BN/MoS2) were facilitated to generate more active sites. Furthermore, the asymmetric supercapacitor of Ge-decorated h-BN/MoS2 amplified the capacitance to 558.53 F g−1 at 1 A g−1 current density and 159.19 F g−1 at 10 A g−1, in addition to a retention rate of 85.69% after 2000 cycles. Moreover, the Ge-decorated h-BN/MoS2 catalyst realized a low over-potential value, with an RHE of 0.57 (HER) at 5 mA/cm2, a Tafel value of ∼204 mV/dec, and long-term electrolysis stability of 10 h. This work may open the door for further investigations on metal-decorated heterostructures, which have a significant potential for both supercapacitor and water-splitting applications.
A Survey on SDN and SDCN Traffic Measurement: Existing Approaches and Research Challenges
Authors: Islam MD Samiul , Al-Mukhtar Mohammed , Khan MD Rahat Kader , Hossain Mojammel
Published: April 2023

The Software-Defined Network (SDN) is a next-generation network that uses OpenFlow to decouple the control plane from the data plane of forwarding devices. Other protocols for southbound interfaces include ForCES and POF. However, some security issues might be in action on the SDN, so that attackers can take control of the SDN control plane. Since live video calling, QoS control, high bandwidth needs, and resource management are inevitable in any SDN/Software-Defined Cellular Network (SDCN), traffic monitoring is an integral approach for safeguarding against DDoS, heavy hitters, and superspreaders. In such a scenario, SDN traffic measurement comes into action. Thus, we survey SDN traffic measurement solutions to assess how these solutions can make a secure, efficient, and robust SDN/SDCN architecture. This research classifies SDN traffic measurement solutions according to network application behavior and compares several ML approaches. Furthermore, we find out the challenges related to SDN/SDCN traffic measurement and the future scope of research, which will guide the design and development of more advanced traffic measurement solutions for a scalable, heterogeneous, hierarchical, and widely deployed SDN/SDCN architecture. In more detail, we list different kinds of practical machine learning (ML) approaches to analyze how we can improve traffic measurement performances. We conclude that using ML in SDN traffic measurement solutions will help secure SDNs/SDCNs in complementary ways.
Electrochemical Biosensor for Evaluation of Environmental Pollutants Toxicity
Authors: Islam Md. Saiful , Sazawa Kazuto , Sugawara Kazuharu , Kuramitz Hideki
Published: April 2023

Electrochemical biosensors that combine high selectivity of biochemical affinity with precise electrochemical detection are one of the most necessary and powerful tools for assessing environmental pollution. This review addresses electrochemical biosensors that assess environmental pollutant toxicity. Electrochemical biosensors using enzyme activity inhibition, DNA, whole cells, and cytochrome P450 will be introduced, their advantages and applications will be discussed, and trends and challenges for designing reliable sensors for practical use will be addressed.
Uncovering the Potential of Multi-Temporally Integrated Satellite Imagery for Accurate Tree Species Classification
Authors: Cha Sungeun , Lim Joongbin , Kim Kyoungmin , Yim Jongsoo , Lee Woo-Kyun
Published: April 2023

In this study, prior to the launch of compact advanced satellite 500 (CAS500-4), which is an agriculture and forestry satellite, nine major tree species were classified using multi-temporally integrated imageries based on a random forest model using RapidEye and Sentinel-2. Six scenarios were devised considering the composition of the input dataset, and a random forest model was used to evaluate the accuracy of the different input datasets for each scenario. The highest accuracy, with accuracy values of 84.5% (kappa value: 0.825), was achieved by using RapidEye and Sentinel-2 spectral wavelengths along with gray-level co-occurrence matrix (GLCM) statistics (Scenario IV). In the variable importance analysis, the short-wave infrared (SWIR) band of Sentinel-2 and the GLCM statistics of RapidEye were found to be sequentially higher. This study proposes an optimal input dataset for tree species classification using the variance error range of GLCM statistics to establish an optimal range for window size calculation methodology. We also demonstrate the effectiveness of multi-temporally integrated satellite imageries in improving the accuracy of the random forest model, achieving an approximate improvement of 20.5%. The findings of this study suggest that combining the advantages of different satellite platforms and statistical methods can lead to significant improvements in tree species classification accuracy, which can contribute to better forest resource assessments and management strategies in the face of climate change.
Forest Plant Water Utilization and the Eco-Hydrological Regulation in the Karst Desertification Control Drainage Area
Authors: Fan Bo , Xiong Kangning , Liu Ziqi
Published: April 2023

Subtropical forests in southwestern karst areas are the top priority for ecosystem restoration, as studying the water absorption strategies of the major plants in these regions is crucial to determining the species distribution and coexistences within these seasonal subtropical forests, which will help us to cope with the forest ecosystem crisis under future climate change. We used the stable isotope ratios (δD and δ18O) of tree xylem and soil water to assess the seasonal changes in the water use patterns and hydrological niche separations of four dominant tree species in seasonal subtropical forests in southwestern karst areas. The results showed that the soil water’s isotopic composition varied gradiently in the vertical direction and that the variation of the soil water’s isotopic composition was greater in the shallow layer than in its depths. Juglans regia (HT) mainly depended on soil water at a depth of 30–60 cm (41.8 ± 6.86%) and fissure water (32.5 ± 4.21%), while Zanthoxylum bungeanum Maxim (HJ) and Eriobotrya japonica Lindl (PP) had the same water use pattern. In the dry season, HT competed with HJ and PP for water resources, and in the rainy season, HJ and PP competed with Lonicera japonica (JYH), while HJ competed with PP all the time. JYH and HT were in a separate state of hydrologic niche and they did not pose a threat to each other. Coexisting trees are largely separated along a single hydrological niche axis that is defined by their differences in root depth, which are closely related to tree size. Our results support the theory of hydrological niche isolation and its potential responses in relation to drought resistance. This study provides a method for determining more efficient plant combinations within karst forest vegetation habitats and its results will have important implications for ecosystem vegetation restoration.