Interconnect Architecture Research Articles

Extraction of Hydroxyapatite from Camel Bone for Bone Tissue Engineering Application.

Waste tissues such as mammalian bone are a valuable source from which to extract hydroxyapatite. Camel bone-based hydroxyapatite (CBHA) was extracted from the femur of camel bones using a defatting and deproteinization procedure. The extracted CBHA was mechanically, chemically, physically, morphologically and structurally characterized. Fourier-Transform Infra-Red (FTIR) spectra, Micro-Raman, and X-ray diffraction analysis confirmed successful extraction of hydroxyapatite. The mechanical properties of the CBHA scaffold were measured using a Universal Instron compression tester. Scanning electron microscopy showed the presence of a characteristic interconnected porous architecture with pore diameter ranging from 50-600 µm and micro-computer tomography (Micro-CT) analysis identified a mean porosity of 73.93. Thermogravimetric analysis showed that the CBHA was stable up to 1000 °C and lost only 1.435% of its weight. Inductively coupled plasma-mass spectrometry (ICP-MS) and Energy-dispersive-X-ray (EDX) analysis demonstrated the presence of significant amounts of calcium and phosphorus and trace ions of sodium, magnesium, zinc, lead and strontium. Following 21 days of incubation in simulated body fluid (SBF), the pH fluctuated between 10-10.45 and a gradual increase in weight loss was observed. In conclusion, the extracted CBHA is a promising material for future use in bone tissue regeneration applications.

Geophysical-laboratory data integration for estimation of groundwater volumetric reserve of a coastal hinterland through optimized interpolation of interconnected geo-pore architecture

Geophysical-laboratory data integration for estimation of groundwater volumetric reserve of a coastal hinterland through optimized interpolation of interconnected geo-pore architecture

Preparation and Characterization of Porous Poly(Lactic Acid)/Poly(Butylene Adipate-Co-Terephthalate) (PLA/PBAT) Scaffold with Polydopamine-Assisted Biomineralization for Bone Regeneration.

The development of scaffolds that simultaneously provide porous architectures and osteogenic properties is the major challenge in tissue engineering. Herein, a scaffold with high porosity and well interconnected networks, namely poly(lactic acid)/poly(butylene adipate-co-terephthalate) (PLA/PBAT), was fabricated using the gas foaming/ammonium bicarbonate particulate leaching technique. Mussel-inspired polydopamine (PDA)-assisted biomineralization generated by two-step simple soaking in dopamine solution and 10× SBF-like solution was performed to improve the material's osteogenicity. Highly porous scaffolds available in less organized opened cell structures with diameters ranging from 10 µm to 100 µm and 200 µm to 500 µm were successfully prepared. The well interconnected porous architectures were observed through the whole thickness of the scaffold. The even deposition of the organic-inorganic bioactive mineralized layer composed of PDA and nano-scale hydroxyapatite (HA) crystals on the scaffold surface was evidenced by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The developed scaffold exhibited high total porosity (84.17 ± 1.29%), a lower surface contact angle (θ = 45.7 ± 5.9°), lower material degradation rate (7.63 ± 2.56%), and a high level of material biocompatibility. The MTT assay and Alizarin Red S staining (ARS) confirmed its osteogenic enhancement property toward human osteoblast-like cells (MG-63). These results clarified that the developed porous PLA/PBAT scaffold with PDA-assisted biomineralization exhibited good potential for application as a biomaterial for bone tissue regeneration and hard tissue engineering.

Hierarchical ZnO arrays engineered hollow carbon nanofibers derived from metal-organic frameworks for flexible supercapacitors

Carbon nanofibers (CNFs) have been playing an essential role in addressing the challenges of the flexibility in energy storage devices. However, the unsatisfactory electrochemical performance and poor electrical conductivity are often caused by insufficient physical contact points of CNFs. The design and implementation of unique electrodes are expected to overcome these issues. Here, the N-doped hierarchical porous carbon nanofibers (NCNFs) hollow framework derived from metal-organic frameworks (MOFs) is fabricated, which is decorated with high conductive reduced graphene oxide rGO and single-crystal ZnO nanorod for engineering the binder-free flexible electrodes NCNF@rGO-x@ZnO. The obtained NCNF@rGO-7@ZnO electrode exhibits the desired specific capacitance of 473 F g-1. An assembled hybrid supercapacitor exhibits the high energy density of 35.16 Wh kg-1 at the power density of 747.2 W kg-1, and superior cycling life. Given these advantages, the NCNF@rGO-7@ZnO is selected as the electrode in a flexible and foldable supercapacitor. There is exceptional flexibility and no visible capacitance loss when the supercapacitor bending at different angles. Furthermore, a timer is successfully driven by two supercapacitor devices connected in series. Hence, a flexible binder-free electrode with excellent electrochemical performance can be obtained by engineering the structure into a hollow interconnected architecture and the rational design of materials.

Highly compressible and environmentally adaptive conductors with high-tortuosity interconnected cellular architecture

Conductive hydrogels that are highly elastic, fatigue resistant and environmentally adaptive are promising materials in the fields of wearable electronics, bioelectronics and soft robotics. However, these materials are challenging to develop, especially for use in harsh environments including organic solvents and extreme temperatures. Here we report a simple method for the fabrication of highly compressible and fatigue-resistant conductive hydrogels with reinforced-concrete-type constituents and high-tortuosity interconnected cellular architecture through a self-assembly and two-stage in situ polymerization process. The obtained composites exhibit excellent mechanical compressibility with negligible residual strain at 50% strain for >104 cyclic loadings both in air and water. Due to the structure-favoured anisotropic response to tensile deformations coupled with elastic recovery, the hydrogel is endowed with sensing dimensions which allow the direction and velocity of movement on the sensor surface to be distinguished. In addition, by interpenetrating with an oleophilic polymer network, highly elastic and adaptive organohydrogels are developed with outstanding sensing performance in a wide variety of organic solvents and cryogenic temperatures. These materials may therefore be suitable for use in flexible and wearable devices in harsh environments.

Nanofibrous Wound Healing Nanocomposite Based on Alginate Scaffold: In Vitro and In Vivo Study

The combination of nanofibers with 3D scaffolds has shown promising results as the wound healing/dressing/care biomaterials. The present study aimed to fabricate and optimized alginate hydrogel composited by Lignin-derived carbon nanofibers (CNFs). The nanofibers were obtained from electrospun Lignin nanofibers as the precursor through two steps heat treatments. The synthesized nanofibers blended with an alginate polymer solution with different concentrations (1, 5, and 10 wt.%) and cross-linked using CaCl2 through the physical cross-linking. The findings illustrated that the prepared Lignin and CNFs have acceptable diameter. The composited Alginate hydrogels possessed a porous internal-structure with interconnected architecture. The fabricated hydrogel exhibited proper porosity and swelling behavior beneficial for wound healing application. The In Vitro experiments revealed that the hydrogel were red blood cell (RBC)-compatible, cytocompatible, and induced proliferative effects on cells. The animal experiments indicated that the application of the hydrogel promoted the process of wound healing. These observations implied that the prepared hydrogel nanocomposites exhibited promising properties and can be considered as wound healing nanobiomaterials.

High performance supercapacitors using selenium partially reduced Co3O4 on carbon cloth electrode with 3D interconnected architecture nanowires

The electrodes with high conductivity, large specific surface area and homogeneous pore size distribution are greatly desirable for supercapacitors applications. Herein, a hydrothermal and subsequent annealing approach was adopted to fabricate 3D interconnected nanowires architecture of selenium partially reduced spinel Co3O4 grew on the carbon cloth (COS@CC). The binder-free COS@CC electrode displays excellent specific capacitance, 1046.9 C g−1 at 1 A g−1, superior rate capability, 51.6% capacitance retention and superior cyclic stability, 92.0% capacitance retention after 15,000 cycles. These electrochemical performances were found to be better than that of the Co3O4@CC electrode. The enhanced electrochemical performance was ascribed to the fact that 3D interconnected architecture nanowires could shorten the ion transfer distance and heighten the rate of the redox reaction. In addition, increased specific surface area and homogeneous mesopore size distribution could assist effective diffusion and transfer of OH– between electrodes and electrolyte. The enhancement of conductivity, which is caused by the selenium partial reduction and more oxygen vacancies in the structure, facilitates electrons transfer and consequently improves the electrochemical properties of supercapacitors. These remarkable electrochemical performances indicate that the CSO@CC can be employed for developing high-energy and power-density supercapacitors.

Highly reversible Zn metal anodes enabled by multifunctional poly zinc acrylate protective coating

The application of low-cost and high-safety aqueous Zn metal batteries is seriously hindered by Zn anode stemming from its uncontrollable dendrite growth and detrimental water-induced side reactions. Herein, a zinc-enriched and negatively charged poly zinc acrylate (PZA) polyelectrolyte with hydrophobic 3D network is firstly constructed on Zn surface through facile UV light irradiation of ZA monomer. The as-obtained PZA coating exhibits a strong adhesion to Zn foil, persistently protecting Zn from water corrosion. Furthermore, the 3D interconnected network architecture favors the fast transport of Zn2+. Meanwhile, the anions can be shielded and desolvation of hydrated Zn2+ is accelerated. Notably, the self-contained Zn2+ in PZA can avoid the supply of sluggish ions. Accordingly, the Zn@PZA anode delivers a low energy barrier and high Zn2+ transference number. Moreover, it endows a superior Coulombic efficiency of 99.7 % and long-life dendrite-free plating/stripping (10 mA cm−2, 2 mAh cm−2). The MnO2||Zn@PZA full cell displays a highly stable cycling behavior for over 700 cycles with a high capacity retention of 95.1 % at 1 A/g together with a satisfactory rate performance. This work delivers an affordable and facile strategy to realize the high reversibility and stability of Zn anodes.

Enhanced bone tissue regeneration with hydrogel-based scaffolds by embedding parathyroid hormone in mesoporous bioactive glass.

To evaluate hydrogel-based scaffolds embedded with parathyroid hormone (PTH)-loaded mesoporous bioactive glass (MBG) on the enhancement of bone tissue regeneration in vitro. MBG was produced via sol-gel technique followed by PTH solution imbibition. PTH-loaded MBG was blended into the hydrogels and submitted to a lyophilisation process associated with a chemical crosslinking reaction to the production of the scaffolds. Characterisation of the MBG and PTH-loaded MBG scaffolds, including the scanning electron microscope (SEM) connected with an X-ray detector (EDX), Fourier transform infrared (FTIR), compression strength, rheological measurements, swelling and degradation rates, and PTH release analysis, were performed. Also, bioactivity using simulated-body fluid (SBF), biocompatibility (MTT), and osteogenic differentiation analyses (von Kossa and Alizarin Red stainings, and μ-computed tomography, μCT) of the scaffolds were carried out. SEM images demonstrated MBG particles dispersed into the hydrogel-based scaffold structure, which was homogeneously porous and well interconnected. EDX and FTIR revealed large amounts of carbon, oxygen, sodium, and silica in the scaffold composition. Bioactivity experiments revealed changes on sample surfaces over the analysed period, indicating the formation of carbonated hydroxyapatite; however, the chemical composition remained stable. PTH-loaded hydrogel-based scaffolds were biocompatible for stem cells from human-exfoliated deciduous teeth (SHED). A high quantity of calcium deposits on the extracellular matrix of SHED was found for PTH-loaded hydrogel-based scaffolds. μCT images showed MBG particles dispersed into the scaffolds' structure, and a porous, lamellar, and interconnected hydrogel architecture. PTH-loaded hydrogel-based scaffolds demonstrated consistent morphology and physicochemical properties for bone tissue regeneration, as well as bioactivity, biocompatibility, and osteoinductivity in vitro. Thus, the scaffolds presented here are recommended for future studies on 3D printing. Bone tissue regeneration is still a challenge for several approaches to oral and maxillofacial surgeries, though tissue engineering applying SHED, scaffolds, and osteoinductive mediators might help to overcome this clinical issue.

Synergistic Engineering of Heterointerface and Architecture in New‐Type ZnS/Sn Heterostructures In Situ Encapsulated in Nitrogen‐Doped Carbon Toward High‐Efficient Lithium‐Ion Storage

AbstractEngineering heterogeneous composite electrodes consisting of multiple active components for meeting various electrochemical and structural demands have proven indispensable for significantly boosting the performance of lithium‐ion batteries (LIBs). Here, a novel design of ZnS/Sn heterostructures with rich phase boundaries concurrently encapsulated into hierarchical interconnected porous nitrogen‐doped carbon frameworks (ZnS/Sn@NPC) working as superior anode for LIBs, is showcased. These ZnS/Sn@NPC heterostructures with abundant heterointerfaces, a unique interconnected porous architecture, as well as a highly conductive N‐doped C matrix can provide plentiful Li+‐storage active sites, facilitate charge transfer, and reinforce the structural stability. Accordingly, the as‐fabricated ZnS/Sn@NPC anode for LIBs has achieved a high reversible capacity (769 mAh g−1, 150 cycles at 0.1 A g−1), high‐rate capability and long cycling stability (600 cycles, 645.3 mAh g−1 at 1 A g−1, 92.3% capacity retention). By integrating in situ/ex situ microscopic and spectroscopic characterizations with theoretical simulations, a multiscale and in‐depth fundamental understanding of underlying reaction mechanisms and origins of enhanced performance of ZnS/Sn@NPC is explicitly elucidated. Furthermore, a full cell assembled with prelithiated ZnS/Sn@NPC anode and LiFePO4 cathode displays superior rate and cycling performance. This work highlights the significance of chemical heterointerface engineering in rationally designing high‐performance electrodes for LIBs.

Shear‐Induced Macropore‐Infused Nanocomposite Emulsion Thermosets

AbstractTo create macropore‐infused nanocomposite emulsion thermosets (MINET), a mixing pathway is demonstrated in which a viscous fluid is kinetically trapped by high shear mixing of immiscible liquids, surfactant, and nanoparticles. The MINETs are prepared from common ingredients that are widely employed in industry, including epoxy resin, vegetable oil, epoxidized soybean oil, and different types of nanoparticles such as silica, activated carbon, alumina, and zinc oxide. MINETs prepared by the presented route are processed at ambient conditions and exhibit low shrinkage (<2%). Furthermore, they are suitable to form macro‐ to microscale structures with high precision and various controlled porosity. The interconnected porous architecture of MINET is even preserved in molded micrometer‐scale features and thus ensures mass transport through multiscale structures. In combination with standard microembossing or photolithography, the high throughput microfabrication of microstructured architectures with tunable pore sizes in a wide range (≈100 nm to ≈10 µm) is possible. As one application example, the parallel production of multiplexed electrospray emitters is demonstrated.

A novel hybrid robust architecture for automatic screening of glaucoma using fundus photos, built on feature selection and machine learning‐nature driven computing

AbstractGlaucoma is a leading cause of permanent vision loss. Early detection and treatment of this infection is critical for recovery and slowing the progression of vision loss. An efficient novel system focused on customized particle swarm optimization (CPSO) and four state‐of‐the‐art machine‐learning classifiers is proposed to boost prediction performance. This interconnected architecture detects glaucoma through five main phases: (1) pre‐processing, (2) segmentation, (3) feature extraction, (4) finding the best scored features, and (5) classification using the proposed CPSO‐machine learning dependent classifier. The subject images belong to the publically available benchmark Digital Retinal Images for Optic Nerve Segmentation retinal fundus data set. Rather than focusing on the initial 20 extracted features of the retinal fundus, half of the critical features are chosen to form a feature vector based on scores provided by the univariate method and the feature importance method separately. These features are fed into this system for training, testing, and multiple sets of results are created as a result of multiple combinations of CPSO and supervised machine‐learning classifiers. These result sets are evaluated using six efficiency metrics. According to the simulation results, the best output is recorded when a univariate selected feature vector is fed into the CPSO—K‐nearest neighbour dependent hybrid method. This model outperformed other models with a maximum accuracy of 0.99, a specificity of 0.96, a sensitivity of 0.97, a precision of 0.97, an F1‐score of 0.97, and a Kappa of 0.94. A fivefold cross‐validation method is used to derive the values. This research would help to achieve good levels of glaucoma care since the proposed system is excellent at distinguishing between stable and glaucomatous eyes. For ophthalmologists, this new technique can be used as second opinion for improving diagnostic accuracy for glaucoma.

CoM/diatomite (M = Mg and Al) for the activation of peroxymonosulfate to degrade atrazine in water: Effect of preparation method, role of acidic/basic sites, and catalytic mechanism

A cost-effective and eco-friendly catalyst is desirable for activating peroxymonosulfate (PMS) into reactive oxygen species (ROS) to abate organic pollutants in water. It is the first-ever research to synthesize a highly efficient PMS-activator by incorporating cobalt on as-synthesized Mg- and Al-loaded diatomite (DM) by impregnation (IM) and precipitation-deposition (PD) methods. The catalysts showed a mixture of the plate and pinnate-like morphologies. Atrazine (ATZ) degradation by diatomite-based catalysts followed the order of Co6Mg10/DM-IM > Co6Mg10/DM-PD > Co6Al10/DM-IM > Co6Al10/DM-PD. ATZ removal by sole PMS and adsorption was negligible. The Co6Mg10/DM-IM morphology, structure, and catalytic activity were well-maintained after reuse, with minor Co (0.05 mg L−1) and Mg (3.05 mg L−1) leaching. The ROS (OH, SO4−, O2− and 1O2) were generated due to redox couples [Co2+/Co3+, and O2−/O2] and decomposition of PMS. Improved catalytic efficiency was ascribed to the Co/Mg and Co/Al synergism, spatially interconnected architecture with lower charge-transfer resistance, open porous structure, diffusion-friendly channels, abundant OH groups, and ROS generation. This research provides an insight into how tuning the surface chemistry of DM in terms of acidity and basicity can enhance the catalytic activity of other transition metals (such Fe, Mn, Cu, and their composites) for AOPs.

A computational approach from design to degradation of additively manufactured scaffold for bone tissue engineering application

PurposeThis paper aims to develop a computational approach to analyze the mechanical behavior, perfusion bioreactor test and degradation of the designed scaffolds. Five types of pore architecture scaffolds have been made using a computer-aided designed tool and fabricated through fused deposition modeling.Design/methodology/approachCompressive structural analysis has been performed using the finite element method to forecast the mechanical performance of the scaffolds. Also, the experimental study was done to validate the simulation outcomes. A computational fluid dynamic analysis was performed to ascertain the fluid pressure distribution, velocity profile, wall shear stress, strain rate and permeability of scaffolds. The interconnected pore architecture of the scaffolds plays a crucial role in enhancing the mechanical properties and fluid flow characteristics.FindingsThe scaffolds with continuous vertical support columns resulted in better strength because they provide better ways to transfer the load. The pore architecture of the scaffold plays a significant role in the path of fluid flow. Scaffolds with regular interconnected pore architecture showed better accessibility of the fluid. The degradation analysis showed that the degradation rate is dependent on the architecture of the scaffolds because of different surface area to volume ratios.Originality/valueThe simulation results provide a straightforward prediction of the scaffold suitability in terms of mechanical strength, perfusion and degradation behavior.Graphical abstract

Poly(butylene succinate) matrices obtained by thermally-induced phase separation: Pore shape and orientation affect drug release

Poly(butylene succinate) (PBS) scaffolds with 3D microporous interconnected architecture and crystallized PBS substructures have been prepared by thermally-induced phase separation (TIPS). Curcumin (CUR) and piperine (PIP) natural drugs were incorporated into the matrices during a one-step fabrication protocol. Alterations in TIPS parameters such as solvent system (1,4 dioxane (DXN) or THF) and cooling condition (intensity and direction of thermal gradient) affected the phase separation process and the scaffold properties. Controlling the crystallization of DXN in a uniaxial direction, resulted in the formation of microtubular scaffolds with oriented porosities. Well-developed PIP crystals and matrix-integrated CUR agglomerates were uniformly distributed throughout the scaffolds. The integration of CUR to the polymer matrix was confirmed by physicochemical evaluations, attributed to a possible interaction with PBS, resulting in a slower release than PIP. The scaffolds with uniaxially-oriented porosities displayed a greater sustained release (only 50–60% after 170 h) due to the restricted drug diffusion through their dense spherulitic pore walls. Due to such structure and smoother well-arranged surfaces, the oriented scaffolds also exhibited greater biocompatibility. Our results reveal the positive influence of TIPS-derived structural orientation on properties of PBS matrices for cell/drug delivery. • Controlling the porous architecture is crucial to designing cell/drug carriers. • Porosity orientation affects the final properties of the polymeric matrix. • Herein, porosity orientation has been controlled by adjusting TIPS thermal gradient. • Uniaxially-aligned pores had spherulitic and denser walls compared to random ones. • Such a structure could impede the drug diffusion, being achieved a sustained release.

IoT System for Detecting the Condition of Rotating Machines Based on Acoustic Signals

Modern predictive maintenance techniques have been significantly improved with the development of Industrial Internet of Things solutions which have enabled easier collection and analysis of various data. Artificial intelligence-based algorithms in combination with modular interconnected architecture of sensors, devices and servers, have resulted in the development of intelligent maintenance systems which outperform most traditional machine maintenance approaches. In this paper, a novel acoustic-based IoT system for condition detection of rotating machines is proposed. The IoT device designed for this purpose is mobile and inexpensive and the algorithm developed for condition detection consists of a combination of discrete wavelet transform and neural networks, while a genetic algorithm is used to tune the necessary hyperparameters. The performance of this system has been tested in a real industrial setting, on different rotating machines, in an environment with strong acoustic pollution. The results show high accuracy of the algorithm, with an average F1 score of around 0.99 with tuned hyperparameters.

VLCC‐Q: Very low computational complexity optical interconnect architecture with queueing for reducing delay and back pressure probability in data center networks

SummaryAn architecture which promised very low computational complexity for optical interconnects in DCN was previously proposed, the very low computational complexity (VLCC) architecture. In this article, we present enhancement over VLCC architecture called very low computational complexity optical interconnect architecture with queueing (VLCC‐Q) architecture which represents M/D/64 output queue. Contention occurs at the destination if the source nodes which access the same destination node exceeds 64. The performance analysis is carried out through mathematical analysis, TCP simulation in NS2 and eye diagram of optical signal. The mathematical analysis gives theoretical bounds of optical switch, whereas TCP analysis gives practical situation results and eye diagram shows that optical signal is practically recoverable after the optical signal passes through various optical components of the optical interconnect. Results clearly show that VLCC‐Q outperforms VLCC architecture in terms of throughput increase, delay reduction and back pressure probability reduction.

TEMPO-mediated oxidized cellulose nanofibers-Cd2+ derived hierarchically porous carbon aerogel for oxygen reduction electrocatalysis

• TOCNFs-Cd 2+ aerogel is constructed via the electrostatic and ionic interactions. • Cd metal acts as the thermally sacrificial template to generate ultralight N-CNA-Cd. • N -CNA-Cd has abundant micro-/meso-pores, rich defects, huge SBET and fibrous network. • An impressive ORR electrocatalytic efficacy was obtained on N-CNA-Cd sample. Carbon aerogel (CA) emerges as a kind of burgeoning material platform for electrocatalysis with merits of the 3D porous and interconnected architecture to facilitate the low-resistant mass diffusion and charge transport. There still remain great challenges in fine-tuning the intrinsic chemical nature and creating hierarchically porous microstructure in CA through a sustainable synthesis route. Here, we employed TEMPO-mediated oxidized cellulose nanofibers (TOCNFs) and a thermally sacrificial template Cd metal with low boiling point (767 °C) to assemble TOCNFs-Cd 2+ hydrogel/aerogel, which is then subsequently converted to ultralight N -doped carbon nanofibers aerogel ( N -CNA-Cd) upon pyrolysis at a moderate temperature. Thanks to the presence of abundant interior micro- and meso-pores, rich defects, huge BET specific surface area (1782 m 2 g −1 ) and interconnected fibrous network, the as-obtained N -CNA-Cd samples demonstrate an impressive electrocatalytic efficacy towards oxygen reduction reaction in terms of the positive half-wave potential (0.84 V), large electrochemical active surface area and considerable stability under both alkaline and acidic conditions. This study provides a versatile strategy for designing and engineering carbonaceous aerogels that can be suited for electrocatalysis and energy storage applications from renewable plant cellulose resources.

Bacterial Polyglucuronic Acid/Alginate/Carbon Nanofibers Hydrogel Nanocomposite as a Potential Scaffold for Bone Tissue Engineering.

3D nanocomposite scaffolds have attracted significant attention in bone tissue engineering applications. In the current study, we fabricated a 3D nanocomposite scaffold based on a bacterial polyglucuronic acid (PGU) and sodium alginate (Alg) composite with carbon nanofibers (CNFs) as the bone tissue engineering scaffold. The CNFs were obtained from electrospun polyacrylonitrile nanofibers through heat treatment. The fabricated CNFs were incorporated into a PGU/Alg polymeric solution, which was physically cross-linked using CaCl2 solution. The fabricated nanocomposites were characterized to evaluate the internal structure, porosity, swelling kinetics, hemocompatibility, and cytocompatibility. The characterizations indicated that the nanocomposites have a porous structure with interconnected pores architecture, proper water absorption, and retention characteristics. The in vitro studies revealed that the nanocomposites were hemocompatible with negligible hemolysis induction. The cell viability assessment showed that the nanocomposites were biocompatible and supported bone cell growth. These results indicated that the fabricated bacterial PGU/Alg/CNFs hydrogel nanocomposite exhibited appropriate properties and can be considered a new biomaterial for bone tissue engineering scaffolds.

Deep Reinforcement Learning-Based Adaptive Voltage Control of Active Distribution Networks with Multi-terminal Soft Open Point

The integration of highly penetrated distributed generators (DGs) aggravates the rise of voltage violations in distribution networks. Connected by multi-terminal soft open points (M−SOPs), distribution networks gradually evolve into an interconnected flexible architecture with high controllability. Distribution networks with M−SOPs can exchange active power flexibly, and M−SOPs can provide local reactive power support to alleviate voltage violations. However, conventional model-based M−SOP optimization methods cannot regulate voltage profiles adaptively owing to the rapid fluctuations of DGs. In this paper, a data-driven voltage control method is proposed for M−SOPs using a deep deterministic policy gradient network (DDPG). First, the data-driven voltage control framework is proposed for M−SOPs based on DDPG. The M−SOP−based voltage control problem is reformatted as a Markov decision process (MDP) to construct the DDPG agent. Based on real-time measurement, the DDPG agent can adaptively regulate the M−SOP operation to address the frequent DG fluctuations. Then, a multi-dimensional and dynamic boundary action masking approach is proposed to address the complex coupling in the action space of M−SOPs. Finally, the effectiveness of the proposed method was verified using the IEEE 33-node system. The results show that the proposed method can adaptively alleviate the voltage fluctuations caused by rapid DG power variations.