Structural Conversion Research Articles

Enhanced Gelation Properties and Saltiness Perception of Low-Salt Surimi Gel with Psyllium Husk Powder.

Reducing salt intake is an effective strategy for preventing and managing hypertension and cardiovascular diseases. In this study, psyllium husk powder (PHP) was incorporated into surimi to address the challenges of diminished saltiness and texture in low-salt surimi products. PHP promoted the conversion of α-helix structures into β-sheet and strengthening intermolecular interactions, such as ionic bonds, hydrogen bonds, hydrophobic interactions, and disulfide bonds. The addition of PHP enhanced the connectivity and uniformity of the surimi gel network, resulting in an increase in gel strength from 11.35 to 13.88 N and a reduction in cooking loss from 6.33% to 2.27%. Additionally, the more compact gel network structure improved the fluidity of immobile water within the low-salt surimi gel. The surimi gel containing 1.5% PHP accelerated a 30% higher Na+ release rate compared to the low-salt surimi gel, enhancing the saltiness perception to levels comparable with high-salt surimi gel, as measured by an electronic tongue. These findings present a promising approach to improving the texture and saltiness perception of surimi gel products while reducing salt content.

Structural, electrical, and photothermal conversion studies of Triglycine sulfate/Graphene oxide composites for pyroelectric detector and energy harvesting applications

Abstract The aim of this study is to investigate the figures of merit for pyroelectric detectors and energy harvesting of polycrystalline triglycine sulfate (TGS) loaded with different weight ratios of graphene oxide (GO). FTIR, XRD, and DSC techniques are used to characterize the synthesized composites. Structural changes in TGS upon GO loading correlate to the subsequent variations in composites' dielectric, pyroelectric, optical, and photothermal properties. The results revealed that doping TGS by low content of GO (1% – 5% by weight) could improve its photothermal effectiveness and figures of merit for pyroelectric detectors and energy harvesting applications.

Automated Parametrization Approach for Coarse-Graining Soil Organic Matter Molecules.

Investigating the molecular structure of soil organic matter (SOM), along with its intramolecular interactions and interactions with other soil components and xenobiotics, is essential due to its ecological importance. However, the complexity and heterogeneity of SOM present significant challenges for systematic studies. While experimental methods are commonly employed, atomistic simulations provide a complementary approach to exploring molecular-level processes. The Vienna Soil Organic Matter Modeler 2 (VSOMM2) facilitates the construction of molecular models of SOM systems with various compositions at the atomistic scale, which can then be examined through molecular dynamics (MD) simulations. This study introduces a parametrization strategy that enables the conversion of VSOMM2-generated structures into a coarse-grained representation, thus allowing larger time and length scales to be explored. By employing a conformer search technique, direct construction and analysis of coarse-grained SOM models with diverse compositions were made possible, eliminating the need for atomistic MD simulations. To demonstrate this approach, coarse-grained SOM models were created based on selected samples from the International Humic Substances Society, considering different water content levels for each model. Comprehensive analyses, including density and potential energy profile calculations, revealed a partial correlation with the SOM compositions and demonstrated that electrostatic interactions govern the structural packing. Moreover, a local phase separation process, particularly the formation of SOM voids, was observed over several microseconds, underscoring the advantages of the coarse-graining technique.

A New Proposed Triple Active Bridge Converter for Fuel Cell Applications

This paper deals with a new proposed three port converter structure dedicated for two-input source hybrid systems especially for fuel cell applications. This converter is made up of three-phase triple active bridges which are galvanically isolated by means of three single phase high frequency transformers. The present converter integrates a fuel cell as the primary power source with a battery that stores energy, harnessing the unique benefits of both sources to deliver reliable power to a DC load through a single power conversion stage. In order to control the power flow between the ports, a phase shift control technique has been carried out to generate the control signals of the load and battery side bridges in reference with those of the fuel cell bridge. A detailed analysis of the proposed converter has been presented in this paper. A novel proposed energy management algorithm has been developed. This algorithm provides a robust solution for managing and distributing power flow between the converter's ports, ensuring an optimal balance of power delivery. The algorithm has been rigorously validated through simulations and experimental test, using Dspace 1104 board.

A Novel Mathematical Approach for Inductor-Current Expressions Definition in Multilevel Dual-Active-Bridge Converters

The study of multilevel dual-active-bridge (DAB) converters has garnered significant attention in recent years thanks to their advantages with respect to the conventional two-level (2L) DAB; namely, its greater performance and its capability to operate at higher voltage. The analysis of the converter high-frequency inductor current (iL) is crucial, for instance, to compute its root mean square (RMS) value, required to estimate the conduction losses in the converter. The mathematical expression of iL is piecewise and multiple variations, i.e., modes, exist depending on the modulation parameter values. This increases the complexity of converter performance analytical study. Thus, a more practical and generalizable expression of iL current is desirable. This paper proposes novel compact analytic expressions for the instantaneous and RMS inductor current in the 2L-NL DAB converter, leveraging binary functions to define the piecewise intervals and to identify the mode as a function of the modulation parameter values. The proposed method paves the way for more simple and computationally efficient DAB performance optimization software tools that allow exploring any given converter structures and modulation strategies.

Excellent broadband sound absorption in composites manufactured by embedding piezoelectric polymer aerogels in porous ceramics

Challenges remain in the design and manufacture of acoustic devices with excellent broadband sound absorption performance. Herein, an efficient acoustic absorber with hierarchical pore structure and additional acoustic-electrical energy conversion mechanism is reported in which combined zirconia porous ceramics and P(VDF-TrFE) piezoelectric aerogels. Reticular cross-scale pore structure enables sound waves to propagate and dissipate effectively. The vibrations generated by piezoelectric aerogels under acoustic excitation further consume sound waves through converting acoustic energy into electrical energy based on the local piezoelectric and triboelectric effect, which improves the medium and low-frequency sound absorption capability. The average sound absorption coefficient of the prepared acoustic composites reaches 0.87 while the noise reduction coefficient is 0.54. Furthermore, the composites also possess low density, high compressive strength, good hydrophobicity and thermal insulation properties for applications. Therefore, this innovative strategy offers new design ideas for the next generation of high-performance acoustic materials with promising applications in transportation and industrial construction.

Characterizing the Structure of Online Conversations Across Reddit

The proliferation of social media platforms has afforded social scientists unprecedented access to vast troves of data on human interactions, facilitating the study of online behavior at an unparalleled scale. These platforms typically structure conversations as threads, forming tree-like structures known as ''discussion trees.'' This paper examines the structural properties of online discussions on Reddit by analyzing both global (community-level) and local (post-level) attributes of these discussion trees. We conduct a comprehensive statistical analysis of a year's worth of Reddit data, encompassing a quarter of a million posts and several million comments. Our primary objective is to disentangle the relative impacts of global and local properties and evaluate how specific features shape discussion tree structures. The results reveal that both local and global features contribute significantly to explaining structural variation in discussion trees. However, local features, such as post content and sentiment, collectively have a greater impact, accounting for a larger proportion of variation in the width, depth, and size of discussion trees. Our analysis also uncovers considerable heterogeneity in the impact of various features on discussion structures. Notably, certain global features play crucial roles in determining specific discussion tree properties. These features include the subreddit's topic, age, popularity, and content redundancy. For instance, posts in subreddits focused on politics, sports, and current events tend to generate deeper and wider discussion trees. This research enhances our understanding of online conversation dynamics and offers valuable insights for both content creators and platform designers. By elucidating the factors that shape online discussions, our work contributes to ongoing efforts to improve the quality and effectiveness of digital discourse.

Exploring and enhancing the accessibility of children's oral health resources (called HABIT) for high risk communities.

Within the city of Bradford in West Yorkshire, South Asian and Eastern European communities have an increased risk of childhood tooth decay, especially among families with Limited English Proficiency. Tooth decay is preventable, with national guidelines advocating home-based behaviours (toothbrushing with fluoride toothpaste and reducing sugar intake). In England, Health Visitors have opportunities to undertake oral health conversations during universal visits for children aged 0-24 months. The HABIT (Health visitors delivering Advice in Britain on Infant Toothbrushing) intervention provides structured oral health conversations, underpinned by complex intervention methodology. A feasibility study found HABIT acceptable to parents, feasible to deliver and led to improvements in home-based behaviours. However, the reach of this original study was limited to those proficient in English. This new study focused on exploring and enhancing the accessibility of the HABIT intervention to parents with Limited English Proficiency. Twenty-four parents participated in interviews and focus groups, with 21 requesting support from interpreters. Community centres and WhatsApp were used to maximise inclusivity. Interviews and focus groups, followed a topic guide and the "Think Aloud" technique, were professionally transcribed, managed in NVivo, and thematically analysed. Team discussions facilitated analytical rigour. Recruitment continued until data saturation. Three themes were developed: (1) Navigating linguistic barriers; (2) Engagement through visuals; and (3) Addressing oral health challenges. Parents employed diverse strategies to interpret resources, including Google Translate, as well as family and wider community members. Consequently, the HABIT resources were modified to include simple text, subtitles, and translation tools. Parents highlighted the benefits of shorter oral health messages with clear visuals to help understanding, and this strategy was applied across all resources. Challenges surrounding children's resistance to toothbrushing, high sugar intake within their wider families and communities, and limited dental access were all raised. The HABIT resources were updated to address these challenges. Collaborative community engagement has enhanced the HABIT resources, enabling access for high-risk communities to preventive oral-health programmes thereby promoting health equity.

Modification of pore structure of coal under hot steam injection as revealed by nuclear magnetic resonance

Heat injection provides a feasible approach for the extremely efficient extraction of coalbed gas. Injecting hot steam can effectively improve the pore structure of coal and increase the permeability of coal. To observe the changes in the pore structure of coal during hot steam injection, low magnetic field nuclear magnetic resonance technology is used to study the variations in the pore structure of coal under different heat injection durations. The results show that hot steam can promote the formation, growth, and expansion of coal pore fissures, thereby enhancing the gas permeability of the coal seam. At the same time, the analysis of relevant nuclear magnetic parameters indicates that when the heat injection duration is 15 minutes, hot steam has the best effect on coal modification. In the early stage of hot steam injection, hot steam stimulates the development of the porous structure. In the middle stage, some pore structures collapse and get blocked due to local thermal stress. In the late stage of hot steam injection, hot steam accelerates the conversion of micropore and mesopore structures into macropore or fissure structures, and hot steam has a significant modification effect on coal.

Design of novel DC-DC interleaved boost converter for BLDC application

The gradual increment of renewable energy sources (RES) integration in the power generation system is involved in achieving the maximum power demand in the world. In RES fuel cells are used for storage systems of energy. The increment and decrement of voltage level can be controlled by the different types of converters as per the application. Based on that researchers have introduced different types of converters like interleaved converters for voltage-boosting applications to operate the drive. But the converters are involved with higher parts count, switching losses, efficient speed regulation, and torque ripple. To bridge the research the challenges involved in design and operation of converter new interleaved converter structure has been proposed. The validation of proposed converter has been performed in environment of MATLAB/SIMULINK and the required characteristics of the converter and BLDC have been presented. To validate constructional and operational features of converter. The hardware has been developed for 1300 W and operational characteristics have been presented

Double-pancake superconducting coil integrated with DFIG-based wind power systems under voltage-dip events: Design and performance analysis study

The doubly fed induction generator (DFIG)-based wind turbine provides massive development in power generation. Uncertain power oscillations and voltage-dip events affect the stability of the DFIG. To mitigate the effect of voltage-dips in short period, superconducting magnetic energy storage (SMES), which possess rapid energy exchange and high power density, is integrated with large-scale renewable power systems. SMES is integrated at the DC link of the DFIG to ensure the power balance and fault ride-through (FRT) capability. During this operation, frequent current changes occur in the high-temperature superconducting (HTS) coil, which leads to an increase in AC losses. As a remedy, an additional power converter structure controlled with a model-predictive controller (MPC) is proposed. Firstly, a scale-down HTS double-pancake coil model is designed using a finite element model by which transport current loss and magnetic field formulation are studied. Additionally, the critical coil current is also verified through experimental studies. The effectiveness of the proposed MPC-based SMES integrated DFIG on DC link voltage and grid current under IEC-61000-4-11 standard, symmetrical and asymmetrical voltage-dip cases are investigated. The obtained results demonstrate that the proposed system effectively reduces transients in DC link voltage and improves the FRT capabilities of the grid.

Liquid-liquid phase separation and conformational strains of α-Synuclein: implications for Parkinson's disease pathogenesis.

Parkinson's disease (PD) and other synucleinopathies are characterized by the aggregation and deposition of alpha-synuclein (α-syn) in brain cells, forming insoluble inclusions such as Lewy bodies (LBs) and Lewy neurites (LNs). The aggregation of α-syn is a complex process involving the structural conversion from its native random coil to well-defined secondary structures rich in β-sheets, forming amyloid-like fibrils. Evidence suggests that intermediate species of α-syn aggregates formed during this conversion are responsible for cell death. However, the molecular events involved in α-syn aggregation and its relationship with disease onset and progression remain not fully elucidated. Additionally, the clinical and pathological heterogeneity observed in various synucleinopathies has been highlighted. Liquid-liquid phase separation (LLPS) and condensate formation have been proposed as alternative mechanisms that could underpin α-syn pathology and contribute to the heterogeneity seen in synucleinopathies. This review focuses on the role of the cellular environment in α-syn conformational rearrangement, which may lead to pathology and the existence of different α-syn conformational strains with varying toxicity patterns. The discussion will include cellular stress, abnormal LLPS formation, and the potential role of LLPS in α-syn pathology.

Pyrene-Functionalized Ru-Catenated Metallacycles: Conversion of Catenated System to Monorectangle through Aging.

Molecular transformation behavior within a mechanically interlocked system is often assisted by chemical manipulation, such as the inclusion of guest molecules, variation in the solution concentration, or swapping of solvents. We present in this report the synthesis of ruthenium metal and π-conjugated pyrene-based (2 + 2)2 catenated rectangles. Additionally, we discuss the structural conversion of these catenated rectangles into monorectangles through adjustments in concentration and solvent composition. In the presence of a methanol solution, a transformation into monorectangles was observed as the concentration declined. However, interestingly, in the presence of a nitromethane solution, an alteration in conformation to monorectangles was noted by just standing at room temperature for a few hours without any chemical manipulation. Furthermore, theoretical calculations were studied to provide insights into the formation of catenated structures over other potential ring-in-ring or Borromean-ring-type structures. The computational study with the GFN2-xTB method combined with density functional theory (DFT) calculations showed that the lower binding energy within the rectangles favors a catenated structure over other potential ring-in-ring or Borromean-ring-type structures. This work represents a new example of an intertwined structure that self-assembles into a catenated ring rather than a ring-in-ring or Borromean ring and transforms into a monorectangle in nitromethane without the use of any template, alteration in solution concentration, or exchange of solvents, but simply by standing at room temperature.

Honeycomb shaped carbon dopped 1T-2H-MoS2 heterojunction counter electrode with high short current for dye sensitized solar cells

Recent years have witnessed energy crises in various regions and the utilization of new energy is crucial. Dye-sensitized solar cells (DSSCs) are the third generation of photovoltaic cells that are expected to be more cost-effective than other types of solar cells. In this work, we report the synthesis of 1T-2H-MoS2/honeycomb shaped carbon (HSC) heterojunction composite counter electrodes for DSSCs via adding porous carbon in the facile hydrothermal method. The effects of HSC on the morphology, structure, electrochemical and photoelectric conversion properties of the 1T-2H-MoS2/HSC composites were investigated systematically. Both the results of electrochemical and photoelectric measurement suggest the excellent performance of the reduction of I3- and the regeneration of dye. The whole cell assembled with the MoS2/HSC-5.0 counter electrode achieved a short current density 22.24 mA∙cm−2 and a power conversion efficiency (PCE) of 8.42 %, which is significantly higher than that of the pure MoS2 electrode (5.89 %) and Platinum electrode (6.76 %), implying the MoS2/HSC-5.0 composite is a promising candidate for counter electrodes catalyst of DSSCs.

Modulation strategy design method for single-inductor multi-port converter based on reinforcement learning

Single-inductor multi-port converters have the characteristics of "more silicon and less magnetism" and have great application potential in many fields. However, single-inductor multi-port converters have many switching modes and the modulation strategy design is complex. The current design method is to manually select the switching mode sequence and perform modal analysis. The design process requires power electronics expertise and experience. This paper proposes a modulation strategy design method for single-inductor multi-port converters based on reinforcement learning. This method uses a neural network to generate the modulation strategy and adopts a set of simple rules to provide rewards for training the neural network. Through reinforcement learning, the neural network can summarize experience in trial and error without human intervention and finally generate the optimal modulation strategy. This method has many advantages: (1) It only requires known conditions such as port voltage and converter structure as input, and some simple constraints as rewards, avoiding complicated manual design; (2) It can use a neural network to generate the optimal modulation strategy under different operating conditions, and has strong adaptability. Based on this method, a modulation strategy design for a single-inductor multi-port converter is carried out, and the effectiveness of the method is verified by experiments.

Observation of Body‐Centered‐Cubic Cu Nanocluster with Partial Cu(0) Character

The structure of nanoparticles is a key determinant of their material properties. The synthesis of non‐face‐centered‐cubic (FCC) Cu nanoclusters (NCs) with Cu(0) character is still challenging due to their instability. Herein, a Cu(0)‐containing Cu NC is first reported to contain a metallic framework of 23 Cu atoms with a body‐centered‐cubic Cu@Cu8 core, stabilized by 6 triphenylphosphine (TPP) and 18 4‐methylbenzenethiolate ligands, as determined by single‐crystal X‐ray crystallography. The observed structure stands in stark contrast to the FCC and other structures reported for Cu NCs. Moreover, this newly formed NC could react with Au+ ion with controlled concentration, rapidly yielding another identifiable and bright red‐emitting AuCu14 cluster upon irradiation. Based on this structural conversion, a new “turn‐on” type of photoluminescent probe can be developed for the detection of Au+ ion with an ultrafast response time (30 s) at a low detection limit (0.13 ppm). This work provides a new way of understanding the growth of metal clusters and exploring their applications in luminescent sensors.

Compilation of Shape Operators on Sparse Arrays

We show how to build a compiler for a sparse array language that supports shape operators such as reshaping or concatenating arrays, in addition to compute operators. Existing sparse array programming systems implement generic shape operators for only some sparse data structures, reduce shape operators on other data structures to those, and do not support fusion. Our system compiles sparse array expressions to code that efficiently iterates over reshaped views of irregular sparse data structures, without needing to materialize temporary storage for intermediates. Our evaluation shows that our approach generates sparse array code competitive with popular sparse array libraries: our generated shape operators achieve geometric mean speed-ups of 1.66×–15.3× when compared to hand-written kernels in scipy.sparse and 1.67×–651× when compared to generic implementations in pydata/sparse. For operators that require data structure conversions in these libraries, our generated code achieves geometric mean speed-ups of 7.29×–13.0× when compared to scipy.sparse and 21.3×–511× when compared to pydata/sparse. Finally, our evaluation demonstrates that fusing shape and compute operators improves the performance of several expressions by geometric mean speed-ups of 1.22×–2.23×.

A novel interleaved BIFRED-Zeta with intelligent MPPT for PV applications

ABSTRACT The current energy perspective postulates profound presence of Renewable Energy Sources (RESs), resulting in need for optimal DC-DC converter design to assure efficient power conversion and minimise losses. By minimising energy losses and improving power quality, an optimal converter design helps ensure a stable and reliable power supply from RESs, which is essential for meeting the growing demand for clean energy. Therefore, this research introduces an innovative Interleaved BIFRED-Zeta converter configuration, designed to meet all criteria associated with an optimal converter design. The interleaved architecture of converter allows the reduction of current ripples and voltage stress along with the improvement of efficiency. Furthermore, the absence of transformer in converter structure enables it to be simple, cost effective and less bulky. The Interleaved Boost Integrated Flyback Rectifier Energy Storage DC-DC (BIFRED)-Zeta converter duty cycle is adjusted continuously using Cascaded Artificial Neural Network (ANN) Maximum Power Point Tracking (MPPT) to further maximise Photovoltaics (PV) system power output. The capability of suggested converter design is demonstrated by the results obtained using simulation and laboratory prototype implementation. Thereby, a peak efficiency of 97.6% is estimated to be achieved using suggested converter design.

Bactericidal and Antifouling Coatings with the "Killing-Repelling-Killing" Triple Function Based on Cationic Copolymers with Structure Conversion and Capsaicin Analogue Release.

The capsaicin analogue N-(4-hydroxy-3-methoxybenzyl) acrylamide (HMBA) was linked with polylauryl methacrylate-b-poly(2-(N,N-dimethylamino)ethyl methacrylate) (PLMA-b-PDMAEMA) via a quaternization reaction with 4-(acrylamidomethyl)-2-methoxyphenyl 2-chloroacetate (AAMPCA). The amphiphilic copolymers were capable of transforming its structure in response to the solvent change from aprotic to protic, which was verified by the 1H NMR spectrum. The resulting cationic copolymers underwent a hydrolysis process in water, yielding zwitterionic groups on surfaces. Meanwhile, the bactericidal reagent HMBA was released. It was proved that the hydrolysis rate of the copolymers accelerated with higher temperature, higher pH value, and higher hydrophilic block units. And the controllable, sustainable release of HMBA was achieved with copolymer-mediated hydrolysis. Protein-repellent and bactericidal tests on the surface of the coating proved that antifouling and bactericidal performances of the coating correlated to the structure conversion abilities of the corresponding copolymer. The dynamic monitoring of Escherichia coli adhesion in 3 h evidenced the antifouling and bactericidal process of copolymers with different block ratios and concentrations. The coating incorporated with 3% PLMA120-b-(PDMAEMA-AAMPCA)120 in polylactic acid base materials showed an adhesion ratio of E. coli less than 1% within 1 h, and the survival ratio of the adhered bacteria is <1%, suggesting its rapid speed and high efficiency in "bacterial repelling and killing". Also, the PLMA120-b-(PDMAEMA-AAMPCA)120 copolymer demonstrated enhanced bactericidal ability compared with the mixture of cationic poly(laruyl methacrylate)120-b-poly(carboxybetaine methacrylate ester)120 (PLMA120-b-PCBMAE120) and free HMBA. The lowest minimal inhibitory concentration was 0.078 mg/mL against Staphylococcus aureus and 0.312 mg/mL against E. coli, respectively.

Simulation and application analysis of a hybrid energy storage station in a new power system

As the proportion of renewable energy infiltrating the power grid increases, suppressing its randomness and volatility, reducing its impact on the safe operation of the power grid, and improving the level of new energy consumption are increasingly important. For these purposes, energy storage stations (ESS) are receiving increasing attention. This article discusses the structure, working principle, and control methods of grid-following and grid-forming energy-storage converters, which are currently commonly used. A simulation analysis was conducted to investigate their dynamic response characteristics. The advantages and disadvantages of two types of energy storage power stations are discussed, and a configuration strategy for hybrid ESS is proposed. This paper presents research on and a simulation analysis of grid- forming and grid-following hybrid energy storage systems considering two types of energy storage according to different capacity scenarios. Finally, a comparative analysis between the systems is presented. A simulation model was established using PSD-BPA (Power System Department-Bonneville Power Administration) to analyze the impact of the capacity ratio of grid-following and grid-forming ESS on their dynamic response characteristics in a hybrid ESS. In addition, a development direction for future ESSs is indicated.