Experimental Verification Research Articles

Performance improvement of magnesium-based hydrogen storage tanks by using carbon nanotubes addition and finned heat exchanger: Numerical simulation and experimental verification

One of the important tasks of improving the properties of metal hydride reactors is the design of system with optimized heat and mass transfer. Many works are devoted to the selection of the optimal heat exchanger for metal hydride hydrogen storage systems. At the same time, it is necessary to consider the composition of the metal hydride bed, which affects thermal conductivity as well. Little attention has been paid to the study of heat transfer properties in hydrogen storage systems with a heat exchanger and a metal hydride bed based on magnesium hydride and carbon nanotubes. In this work we used numerical simulation to determine the effectiveness of carbon nanotubes addition and heat exchangers with different fin number and geometries on high-temperature magnesium-based hydrogen storage tanks performance. It was found, that increasing the number of fins from three to five makes a smaller contribution in the temperature increasing as compared to the addition of three fins to the heater. The three solid, radial and complex fins have a similar effect on the average Mg/MgH2 bed temperature at 60 min. The most optimal fin number and geometry is three radial fins in terms of the efficiency and the volume it occupies. The addition of carbon nanotubes increases the average temperature of the Mg/MgH2 bed by 67 K for a reactor equipped with a heater without fins. Hydrogen storage system with three radial fins and Mg/MgH2 bed enhanced with carbon nanotubes provides an increase in the average bed temperature of about 180 K as compared to system without fins and nanotubes. This leads to a reduction in the hydrogen absorption time to reach 90% saturation by almost 63% for the three radial fins reactor with carbon nanotubes addition to the metal hydride bed. It has been confirmed that the addition of carbon nanotubes to Mg/MgH2 makes a significant contribution to the heat transfer in the metal hydride bed. In addition, it is shown that both an increase in the heat transfer area and the thermal conductivity coefficient leads to a significant improvement in the efficiency of the metal hydride reactor. In the future, the obtained results can be taken into account when designing hydrogen storage systems based on these materials.

Integration of network pharmacology and transcriptomics to explore the mechanism of isoliquiritigenin in treating heart failure induced by myocardial infarction

BackgroundThe inflammatory response and myocardial remodeling play critical roles in the progression of heart failure (HF) following myocardial infarction (MI). Isoliquiritigenin (ISL) possesses anti-inflammatory properties and has been investigated in cardiovascular diseases such as atherosclerosis. However, the effects and mechanism of ISL on MI-induced HF remain unclear. This research aimed to explore the effects and mechanism of ISL in the treatment of HF on the basis of network pharmacology, transcriptomics, and experimental verification. Methods and resultsWe established an MI-induced HF mouse model in which ISL was administered via gavage for 28 days. Ultrasonic cardiogram data were collected from the mice, and pathological staining was conducted. Then, network pharmacology and molecular docking were performed. Transcriptomic analysis was also conducted on mouse myocardial tissue. Ultimately, we integrated transcriptomic data and network pharmacology to reveal the underlying mechanism, with the results verified through in vivo experiments. Our experiments indicated that ISL improved cardiac function, preserved myocardial structure, inhibited collagen fiber accumulation, reduced inflammatory factor secretion, and mitigated myocardial cell apoptosis in mice with MI-induced HF. A combination of transcriptomics and network pharmacology analysis revealed that core targets of ISL related to HF were significantly enriched in the Tumor Necrosis Factor (TNF) signaling pathway. Molecular docking validation demonstrated that ISL shows strong binding to these core targets. Additionally, in vivo experiments verified that ISL protects against HF post-MI by inhibiting the TNF signaling pathway. ConclusionWe clarified the anti-inflammatory and antimyocardial remodeling mechanisms of ISL in the treatment of HF post-MI, which involves the TNF signaling pathway.

Evaluation of the Mechanism of Yishan Formula in Treating Breast Cancer Based on Network Pharmacology and Experimental Verification.

Yishan formula (YSF) has a significant effect on the treatment of breast cancer, which can improve the quality of life and prolong the survival of patients with breast cancer; however, its mechanism of action is unknown. In this study, network pharmacology and molecular docking methods have been used to explore the potential pharmacological effects of the YSF, and the predicted targets have been validated by in vitro experiments. Active components and targets of the YSF were obtained from the TCMSP and Swiss target prediction website. Four databases, namely GeneCards, OMIM, TTD, and DisGeNET, were used to search for disease targets. The Cytoscape v3.9.0 software was utilized to draw the network of drug-component-target and selected core targets. DAVID database was used to analyze the biological functions and pathways of key targets. Finally, molecular docking and in vitro experiments have been used to verify the hub genes. Through data collection from the database, 157 active components and 618 genes implicated in breast cancer were obtained and treated using the YSF. After screening, the main active components (kaempferol, quercetin, isorhamnetin, dinatin, luteolin, and tamarixetin) and key genes (AKT1, TP53, TNF, IL6, EGFR, SRC, VEGFA, STAT3, MAPK3, and JUN) were obtained. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that the YSF could affect the progression of breast cancer by regulating biological processes, such as signal transduction, cell proliferation and apoptosis, protein phosphorylation, as well as PI3K-Akt, Rap1, MAPK, FOXO, HIF-1, and other related signaling pathways. Molecular docking suggested that IL6 with isorhamnetin, MAPK3 with kaempferol, and EGFR with luteolin have strong binding energy. The experiment further verified that YSF can control the development of breast cancer by inhibiting the expression of the hub genes. This study showed that resistance to breast cancer may be achieved by the synergy of multiple active components, target genes, and signal pathways, which can provide new avenues for breast cancer-targeted therapy.

Photothermal-assisted S-scheme heterojunction of NiPS3 nanosheets modified ZnIn2S4 microspheres for promoting photocatalytic hydrogen evolution

Exploring high-efficiency photocatalysts for solar hydrogen (H2) generation through water splitting is of great significance for addressing both energy shortage and environmental contamination. In this work, a facile self-assembly strategy was developed to couple NiPS3 nanosheets (NPS NSs) with ZnIn2S4 (ZIS) microspheres to synthesize NPS NSs/ZIS (NPS/ZIS) composites, featuring a characteristic of S-scheme charge transfer mechanism. The NPS/ZIS composites possess broad-spectrum light absorption property, improved photothermal effect and efficient charge transfer, showcasing exceptional solar-to-chemical energy conversion capability for visible-light-driven photocatalytic hydrogen evolution (PHE). The photothermal effect derived from NPS NSs loading can facilitate charge carrier transfer across the interfaces and surface reaction kinetics. By carefully adjusting the mass ratio of NPS NSs, the optimized 4-NPS/ZIS exhibits excellent stability and significantly improved PHE activity (1827.6 μmol⋅g−1⋅h−1) in water, which is 18.4 times higher than that of bare ZIS (99.4 μmol⋅g−1⋅h−1). Furthermore, the 4-NPS/ZIS also shows the high PHE efficiency of 312.2 μmol⋅g−1⋅h−1 in seawater. Diverse characterization results reveal that the remarkably enhanced PHE performance primarily arises from the synergistic effect of S-scheme heterostructure, heightened light harvesting capacity, and enhanced photothermal effect. On the basis of density functional theory (DFT) simulations and experimental verifications, a possible PHE mechanism via the S-scheme heterojunction with photothermal assistance in NPS/ZIS is proposed. This study serves as inspiration for the development of novel photothermal-assisted S-scheme photocatalysts, paving the way for efficient and sustainable green energy production.

Effect of flow direction on circumferential velocity, radial velocity, and flow resistance characteristics of rotating gap structures

A rotating gap structure is a type of viscous flow resistance using two disks where the rotation of one disk drives the fluid within the gap, generating rotational inertia. This inertia, combined with viscous friction, determines the flow resistance characteristic curve (pressure drop vs flow rate, or Δp-Q curve). By adjusting the disk's rotational speed, the rotational inertia and the Δp-Q curve can be modified. This paper examines how the radial flow direction (positive and negative) affects the circumferential velocity, radial velocity, and the Δp-Q curve of the rotating gap structure through theoretical modeling and experiments. Results show that radial flow direction and rate influence the symmetric distribution of radial velocity and the linear distribution of circumferential velocity, altering the main components of the Δp-Q curve: the viscous flow resistance curve (Δpvis-Q) and the rotational inertia flow resistance curve (Δprot-Q). The study found that the slope of the Δpvis-Q curve is smaller for positive flow than for negative flow due to differences in radial velocity distribution. Additionally, the circumferential velocity is weakened in positive flow and enhanced in negative flow, resulting in a smaller slope of the Δprot-Q curve for positive flow. These factors cause the Δp-Q curve to deviate from linearity, with greater deviation at higher rotational speeds. Finally, experimental verification was conducted, and the measured Δp-Q curve closely matched the theoretical calculations.

Visual liquefaction process of biomass pyrolysis vapors during indirect heat exchange: experimental description, prediction, and verification

Visual liquefaction process of biomass pyrolysis vapors during indirect heat exchange: experimental description, prediction, and verification

Experimental performance verification of an intelligent detection and assessment scheme for disturbances and imbalances of three-phase synchronous machine output using coherence estimators

In this article, power quality disturbances, such as voltage and current unbalances, series and shunt faults, are monitored in three-phase synchronous machines. Because the imbalances affect machine efficiency and service life, it is essential to figure out whether the three-phase voltages/currents are balanced or unbalanced. An integrated detection algorithm is proposed to detect the unbalanced voltages/currents and various abnormal conditions precisely and quickly, which is based on the coherence estimator. Most existing detection methods require more than one cycle time to determine the contingency conditions, while the proposed technique detects these situations in a fast and discrete protection system. The suggested scheme acquires instantaneous measurements of the three-phase voltages and currents taken at the synchronous machine terminals in order to calculate fifteen coherence coefficients that are utilized to detect and assess any unbalance or trouble accurately and swiftly. A new proposal for imbalance and disturbance indicators based on the coherence estimators is developed in this study. Multiple test cases have been conducted to validate the proposed algorithm capabilities using a real power system, which includes a motor-generator set, a three-phase load and measurement transformers. The experimental results have been revealed that the relay reliability and accuracy percentages have been found to be 98.28% and 98.52%, respectively. The quantitative findings of the imbalance and disturbance assessment are recorded.

PHSOR10 Presentation Time: 9:45 AM: Experimental Verification of 106Ru Brachytherapy Dosimetry Data Using Diodes with Traceability to EBRT Metrology Standard and Monte Carlo Calculated Beam Quality Correction Factors

PHSOR10 Presentation Time: 9:45 AM: Experimental Verification of 106Ru Brachytherapy Dosimetry Data Using Diodes with Traceability to EBRT Metrology Standard and Monte Carlo Calculated Beam Quality Correction Factors

Network pharmacology and experimental verification unraveled the mechanism of Bailing Capsule against asthma.

Asthma is a serious public health challenge around the world. Recent studies into traditional Chinese medicine preparations for asthma have yielded promising findings regarding Bailing Capsule's potential in bronchial asthma prevention and treatment. This study aims to initially clarify the potential mechanism of Bailing Capsule in the treatment of asthma using network pharmacology and in vitro experimental approaches. Network pharmacology was adopted to detect the active ingredients of Bailing Capsule via Traditional Chinese Medicine Systems Pharmacology Database, and the key targets and signaling pathways in the treatment of asthma were predicted. Docking and molecular dynamics simulations were conducted to verify the most important interactions formed by these probes within different regions of the binding site. The predicted targets were validated in lipopolysaccharide-induced 16HBE cell experiment. Seven active ingredients were screened from Bailing Capsule, 294 overlapping targets matched with asthma were considered potential therapeutic targets, such as SRC, TP53, STAT3, and E1A binding protein P300. The main functional pathways involving these key targets include phosphatidylinositol 3-kinase/protein kinase B, mitogen-activated protein kinase, renin-angiotensin system and other signaling pathways, which were mainly involved in the inflammatory response, apoptosis, and xenobiotic stimulus. Moreover, molecular docking showed that Cerevisterol have higher affinity for SRC, TP53, STAT3, and E1A binding protein P300 than other main active components, which is close to the docking results of the co-crystallized ligands to proteins. Consequently, Cerevisterol was selected for molecular dynamics simulation and the results show that Cerevisterol can bind most tightly to SRC, TP53, and STAT3. Bailing Capsule can promote the growth of 16HBE cell, reduce the production of IL-4, TNF-α and IL-6, and down-regulate the levels of SRC and STAT3 mRNA. This study preliminarily reveals the potential mechanism of Bailing Capsule against asthma with the aid of network pharmacology and in vitro cell experiment, which provided reference and guidance for in-depth research and clinical application.

Experimental Verifications of Uninterruptible Power Supply Using a Flywheel Motor-generator and a Planetary Gear

Experimental Verifications of Uninterruptible Power Supply Using a Flywheel Motor-generator and a Planetary Gear

Design, Modeling, and Experimental Verification of Passively Adaptable Roller Gripper for Separating Stacked Fabric

Design, Modeling, and Experimental Verification of Passively Adaptable Roller Gripper for Separating Stacked Fabric

Integrating Network Pharmacology and Experimental Verification to Explore the Pharmacological Mechanisms of Cordycepin against Pulmonary Arterial Hypertension in Rats.

Pulmonary Arterial Hypertension (PAH) is a fatal disease with high morbidity and mortality. Cordycepin has anti-inflammatory, antioxidant and immune enhancing effects. However, the role of Cordycepin in the treatment of PAH and its mechanism is not clear. The Cordycepin structure and PAH-related gene targets were obtained from public databases. The KEGG and GO enrichment analysis of common targets was performed in DAVID. PPI networks were also mapped using the STRING platform. AutoDock Vina, AutoDockTools, ChemBio3D and Pymol tools were selected for molecular docking of key targets. The therapeutic effects of Cordycepin on PAH were observed in Monocrotaline (MCT)-induced PAH rats and platelet-derived growth factor BB (PDGFBB)-induced rat pulmonary artery smooth muscle cells (PASMCs). The right ventricular systolic pressure (RVSP) was detected. HE staining, Western Blot, Scratch assay, EDU and TUNEL assays were used, respectively. Through Network Pharmacology and molecular docking, the Cordycepin-PAH core genes were found to be TP53, AKT1, CASP3, BAX and BCL2L1. In MCT-induced PAH rats, the administration of Cordycepin significantly reduced RVSP, and inhibited pulmonary vascular remodeling. In PDGFBB-induced PASMCs, Cordycepin reduced the migration and proliferation of PASMCs and promoted apoptosis. After the Cordycepin treatment, the protein expressions of TP53, Cleaved CASP3 and BAX were significantly increased, while the protein expressions of p-AKT1 and BCL2L1 were significantly decreased in MCT-PAH rats and PDGFBB-induced PASMCs. This study identified that TP53, AKT1, CASP3, BAX, and BCL2L1 were the potential targets of Cordycepin against PAH by ameliorating pulmonary vascular remodeling, inhibiting the abnormal proliferation and migration of PASMCs and increasing apoptosis of PASMCs. which provided a new understanding of the pharmacological mechanisms of Cordycepin in the treatment of PAH.

Controller design and optimal sizing of battery energy storage system for frequency regulation in a multi machine power system

Frequency regulation is one of the key components needed to keep the power grid stable and reliable in the case of an imbalance between generation and load. This study looks at several control techniques for Battery Energy Storage Systems (BESSs) to keep the frequency stable in the power system during generation/load disruptions. This research aims to build several BESS controllers, including the proportional-integral (PI), proportional integral derivative (PID), and Tilt-Integral Derivative (TID) controllers. Also, the BESS controller parameters are optimized and compared by using metaheuristics based particle swarm optimization (PSO) and the BAT algorithm. However, for practical power systems with high MVA ratings, the size of the battery energy storage systems has to be increased considerably to offset frequency deviations. Additionally, by utilizing PSO to reduce the frequency deviations within prescribed limits, this work presents the optimal BESS sizing for multimachine power systems. Furthermore, the research study examines the impact of BESS connected to various voltage levels, such as LV, MV, and HV subgrids. It also examines BESS's role in frequency management, which is an area of expertise that needs further investigation and is anticipated to have a big influence on the frequency stability of the system. Time domain simulations are carried out, which shows that the PSO based controller design is capable of stabilizing the system frequency with superior performance as well as the BESS's capability to participate effectively in frequency regulation. Additionally, this paper also implements the experimental verification through Hardware-in-the-Loop (HIL) simulations to validate the performance and robustness of the proposed control system. The WSCC 9-bus test system is used to demonstrate the BESS's efficacy. The system is modelled and simulated using the DIgSILENT PowerFactory software.

Study on the Mechanism of Alpinia officinarum Hance in the Improvement of Insulin Resistance through Network Pharmacology, Molecular Docking and in vitro Experimental Verification.

Research has elucidated that the pathophysiological underpinnings of non-alcoholic fatty liver disease and type 2 diabetes mellitus are intrinsically linked to insulin resistance (IR). However, there are currently no pharmacotherapies specifically approved for combating IR. Although Alpinia officinarum Hance (A. officinarum) can ameliorate diabetes, the detailed molecular mechanism through which it influences IR has not been fully clarified. To predict the active components of A. officinarum and determine the mechanism by which A. officinarum affects IR. The active compounds and molecular mechanism underlying the improvement of IR by A. officinarum were predicted via network pharmacology and molecular docking. To further substantiate these predictions, an in vitro model of IR was induced in HepG2 cells using high glucose concentrations. Cytotoxicity and oxidative stress levels were evaluated using Cell Counting Kit-8, reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) assay kits. The putative molecular mechanisms were corroborated through Western blot and RT-PCR analyses. Fourteen principal active components in A. officinarum, 133 potential anti-IR gene targets, and the top five targets with degree values were ALB, AKT1, TNF, IL6, and VEGFA. A. officinarum was posited to exert its pharmacological effects on IR through mechanisms involving lipid and atherosclerosis, the AGE-RAGE signaling pathway in diabetic complications, the PI3K-AKT signaling pathway, fluid shear stress, and atherosclerosis. Intriguingly, network pharmacology analysis highlighted (4E)-7-(4-hydroxy-3-methoxyphenyl)-1-phenylhept-4-en-3- one (A14) as the most active compound. Molecular docking studies further confirmed that A14 has a strong binding affinity for the main targets of PI3K, AKT, and Nrf2. The experiments demonstrated that A14 significantly diminished the ROS and MDA levels while augmenting the SOD activity. Moreover, A14 was found to elevate the protein expression of PI3K, AKT, Nrf2, and HO-1, and increase the mRNA levels of these targets as well as NQO1. A. officinarum could play a therapeutic role in IR through multiple components, targets, and pathways. The most active component of A. officinarum responsible for combating IR is A14, which has the ability to regulate oxidative stress in IR-HepG2 cells by activating the PI3K/AKT/Nrf2 pathway. These findings suggest a potential pharmacological intervention strategy for the treatment of IR.

Design and optimization for a longitudinal-flow corn ear threshing device of low loss and low energy consumption

The traditional corn grain harvester threshing device has the problems of high grain breakage rate, high unthreshed grain rate and high energy consumption when harvesting high water content corn ears. A longitudinal-flow corn ear threshing device and its measurement and control system were proposed to overcome these problems. The working performance and energy consumption of the threshing device were optimized by conducting three factors and five levels corn ear threshing experiments. The experiments took the threshing cylinder speed (X1), threshing gap (X2), and guide vane angle (X3) as the experimental factors, and the grain breakage rate (Y1), unthreshed grain rate (Y2), unit energy consumption (Y3), and threshing concave pressure (Y4) as the experimental indicators. According to the experimental results, the quadratic polynomial regression models between experimental indicators and experimental factors were established. Through models optimization, the optimal working parameters for the threshing device were obtained as X1 at 392.40 r/min, X2 at 40.70 mm, and X3 at 33.16°. Through conducting verification experiment, it was found that under the optimal parameters, the experimental indicators were Y1 at 2.32 ± 0.06 %, Y2 at 0.48 ± 0.04 %, Y3 at 2.14 ± 0.10 kJ/kg, and Y4 at 46.28 ± 3.23N. The errors between the experimental results and the quadratic polynomial regression models were less than 5 %, which indicated that the models had high prediction accuracy. Compared with the unoptimized experimental indicators, the optimized experimental indicators Y1, Y2, Y3 and Y4 decreased by 36.26 %, 39.24 %, 14.74 % and 16.27 %, respectively. The working performance of the threshing device was significantly improved, and the energy consumption was significantly reduced. The relevant research could provide reference for the optimization of the mechanical structure and working parameters of the corn ear threshing device.

Biochar coupling induced charge transfer switching of a NiAl2O4/NiCr2O4 photocatalyst to enhance photocatalytic degradation of tetracycline hydrochloride

A series of novel (NiAl2O4 (NAO)/NiCr2O4 (NCO)) (S1)/GL heterojunction photocatalysts, denoting as x%GL/S1 (x = 5, 10, 15 and 20), were prepared by the polyacrylamide gel method combined with low temperature sintering technique. Various characterizations confirm that there is special interfacial contact and charge transfer between NAO, NCO and GL. The 10%GL/S1 heterojunction exhibited the best photocatalytic activity and cyclic stability for the degradation of tetracycline hydrochloride (TC). Compared to NAO, NCO and NAO/NCO, the degradation efficiency of 10%GL/S1 was significantly improved, and the degradation percentage reached 83.2% within 30 min. The activity of 10%GL/S1 was studied in relation to catalyst content, drug concentration, pH value, water quality, and co-existing anion. Trapping experiments and free radical verification experiments confirmed that the holes, hydroxyl radicals and superoxide radicals played crucial roles in the photocatalysis process. Possible pathways for TC degradation were studied by HPLC-MS, and the ecotoxicity of TC and its degradation intermediates was evaluated by T.E.S.T. software. The charge transfer and photocatalytic mechanisms confirm that the introduction of GL enhances the interfacial interaction between the components, promotes the carrier migration efficiency, provides a large number of active sites for 10%GL/S1 heterojunction, and produces active free radicals after redox reaction with photoinduced electrons, effectively improving the degradation efficiency of TC.

Achieving Ultrahigh Efficiency of Triboelectric Nanogenerator Energy Harvesting Systems via Hybrid Electronic‐Spark Power Management

AbstractSignificant efforts are devoted to optimizing the efficiency of triboelectric energy harvesting systems, particularly through the design of an advanced power management system (PMS) for Triboelectric Nanoenerators (TENGs). A critical aspect of PMS is the design and control of switches. However, existing switches face significant limitations. For spark switches, precise control cannot be achieved, and electronic switches can only operate at voltages below several hundred volts which is limited by the risk of electrical breakdown. To address these limitations, a hybrid electronic‐spark switch power management system (HESS) is proposed. HESS changes the connection of capacitors from parallel to series by deploying a maximum voltage tracking switch components at the peak voltage point, resulting in a much‐elevated voltage level to activate the spark switch. This approach achieves precise control of the spark switch for the first time and significantly reduces the operating voltage of electronic switches. Through simulation and experimental verification, HESS achieves the control at a voltage level of 1.8 kV for spark switch, with an electrical component breakdown voltage of only 450 V. The power density of the HESS is 29.8 mW Hz−1 m−2, which is a new record for electronic switches.

Desulfurization Behavior of Magnetite Pellets Reduced by Isothermal Pure Hydrogen

The desulfurization behavior of magnetite pellets reduced by pure hydrogen at isothermal temperature is studied, the mechanism of self‐oxidation desulfurization is put forward, and the thermodynamic theoretical calculation and experimental verification of this mechanism are carried out. The feasibility of the reaction between iron sulfide and Fe3O4 is analyzed by HSC Chemistry 6.0 software. Additionally, a thermal gravimetric analyzer is used to further study the thermal behavior of pellet material under Ar atmosphere from 400 to 1400 K. The results show that the removal of sulfur in the isothermal reduction process of pure hydrogen does not depend on hydrogen phase diffusion and reduction temperature. During the heating process, self‐oxidation desulfurization occurs in the system, and the self‐desulfurization reaction is more inclined to Fe3O4 + FexSy → FeS + SO2. Under the experimental conditions, the temperature range of self‐oxidation desulfurization under conventional thermal field and microwave field is 700–1100 and 370–1140 K, respectively, and the desulfurization rate is 92.9% and 95.8%, respectively. The key to improving desulfurization by microwave radiation is that iron sulfide has good wave‐absorbing characteristics.

Maximizing transmission capacity in optical communication systems utilizing a microresonator comb laser source with adaptive modulation and bandwidth allocation strategies

Traditional optical communication systems employ bulky laser arrays that lack coherence and are prone to severe frequency drift. Dissipative Kerr soliton microcombs offer numerous evenly spaced optical carriers with a high optical signal-to-noise ratio (OSNR) and coherence in chip-scale packages, potentially addressing the limitations of traditional wavelength division multiplexing (WDM) sources. However, soliton microcombs exhibit inhomogeneous OSNR and linewidth distributions across the spectra, leading to variable communication performance under uniform modulation schemes. Here, we demonstrate, for the first time, to our knowledge, the application of adaptive modulation and bandwidth allocation strategies in optical frequency comb (OFC) communication systems to optimize modulation schemes based on OSNR, linewidth, and channel bandwidth, thereby maximizing capacity. Experimental verification demonstrates that the method enhances spectral efficiency from 1.6 to 2.31 bit ⋅ s−1 ⋅ Hz−1, signifying a 44.58% augmentation. Using a single-soliton microcomb as the light source, we achieve a maximum communication capacity of 10.68 Tbps after 40 km of transmission in the C-band, with the maximum single-channel capacity reaching 432 Gbps. The projected combined transmission capacity for the C- and L-bands could surpass 20 Tbps. The proposed strategies demonstrate promising potential of utilizing soliton microcombs as future light sources in next-generation optical communication.

Metadata harvesting for digital library integration in Ukraine: a comparative study of the OAI-PMH protocol and VuFind’s efficacy

Purpose This paper aims to the problem of building an environment to support scientific research in connection with the development of Open Science in Ukraine. Design/methodology/approach An overview of modern portals for aggregating scientific data was conducted. Analysis of available tools and identifying problems that arise when collecting data from digital libraries and journals was conducted. The validity of choosing VuFind as a tool that allows building an extraction–transformation–loading (ETL) approach for data aggregation and bringing the format and values of metadata fields to one view was experimentally verified. Findings During the experimental verification, problems related to the fact that the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) protocol does not have strict requirements for the data structure, which lead to the complexity of integration, despite the fact that this protocol occupied a leading position, were noted. To simplify these problems, an ETL approach that allowed for the use of ontological methods (e.g. data mapping, linked data and dictionaries to improve the semantics of data for integration processes) was considered. A review of the possibilities of modern tools for OAI-PMH integration, which were actively supported and developed, was conducted. Originality/value This paper was an attempt to outline the problems that arose in integrating resources, with the aim of developing future integration protocols that would have simple means of semantic data validation and built-in ETL mechanism.