bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Photobiomodulation Combined with Fibrin Sealant and Bone Substitute Improving the Bone Repair of Critical Defects
Authors: Pomini Karina Torres , Buchaim Daniela Vieira , Bighetti Ana Carolina Cestari , Andreo Jesus Carlos , Rosso Marcelie Priscila de Oliveira , Escudero José Stalin Bayas , Della Coletta Bruna Botteon , Alcalde Murilo Priori , Duarte Marco Antonio Hungaro , Pitol Dimitrius Leonardo , Issa João Paulo Mardegan , Ervolino Edilson , Moscatel Matheus Bento Medeiros , Bellini Márcia Zilioli , Souza Alexandre Teixeira de , Soares Wendel Cleber , Buchaim Rogerio Leone
Published: October 2022

In this preclinical protocol, an adjunct method is used in an attempt to overcome the limitations of conventional therapeutic approaches applied to bone repair of large bone defects filled with scaffolds. Thus, we evaluate the effects of photobiomodulation therapy (PBMT) on the bone repair process on defects filled with demineralized bovine bone (B) and fibrin sealant (T). The groups were BC (blood clot), BT (B + T), BCP (BC + PBMT), and BTP (B + T + PBMT). Microtomographically, BC and BCP presented a hypodense cavity with hyperdense regions adjacent to the border of the wound, with a slight increase at 42 days. BT and BTP presented discrete hyperdensing areas at the border and around the B particles. Quantitatively, BCP and BTP (16.96 ± 4.38; 17.37 ± 4.38) showed higher mean bone density volume in relation to BC and BT (14.42 ± 3.66; 13.44 ± 3.88). Histologically, BC and BCP presented deposition of immature bone at the periphery and at 42 days new bone tissue became lamellar with organized total collagen fibers. BT and BTP showed inflammatory infiltrate along the particles, but at 42 days, it was resolved, mainly in BTP. In the birefringence analysis, BT and BTP, the percentage of red birefringence increased (9.14% to 20.98% and 7.21% to 27.57%, respectively), but green birefringence was similar in relation to 14 days (3.3% to 3.5% and 3.5% to 4.2%, respectively). The number of osteocytes in the neoformed bone matrix proportionally reduced in all evaluated groups. Immunostaining of bone morphogenetic protein (BMP—2/4), osteocalcin (OCN), and vascular endothelial growth factor (VEGF) were higher in BCP and BTP when compared to the BC and BT groups (p < 0.05). An increased number of TRAP positive cells (tartrate resistant acid phosphatase) was observed in BT and BTP. We conclude that PBMT positively influenced the repair of bone defects filled with B and T.
Poly(2-oxazoline)s as Stimuli-Responsive Materials for Biomedical Applications: Recent Developments of Polish Scientists
Authors: Lusina Aleksandra , Nazim Tomasz , Cegłowski Michał
Published: October 2022

Poly(2-oxazoline)s are the synthetic polymers that are the products of the cationic ring-opening polymerization (CROP) of 2-oxazoline monomers. Due to their beneficial properties, from which biocompatibility, stealth behavior, high functionalization possibilities, low dispersity, stability, nonionic character, and solubility in water and organic solvents should be noted, they have found many applications and gained enormous interest from scientists. Additionally, with high versatility attainable through copolymerization or through post-polymerization modifications, this class of polymeric systems has been widely used as a polymeric platform for novel biomedical applications. The chemistry of polymers significant expanded into biomedical applications, in which polymeric networks can be successfully used in pharmaceutical development for tissue engineering, gene therapies, and also drug delivery systems. On the other hand, there is also a need to create ‘smart’ polymer biomaterials, responsive to the specified factor, that will be sensitive to various environmental stimuli. The commonly used stimuli-responsive biomedical materials are based mostly on temperature-, light-, magnetic-, electric-, and pH-responsive systems. Thus, creating selective and responsive materials that allow personalized treatment is in the interest of the scientific world. This review article focuses on recent discoveries by Polish scientists working in the field of stimuli-responsive poly(2-oxazoline)s, and their work is compared and contrasted with results reported by other world-renowned specialists.
Hydrogel: A Potential Material for Bone Tissue Engineering Repairing the Segmental Mandibular Defect
Authors: Al Maruf D S Abdullah , Ghosh Yohaann Ali , Xin Hai , Cheng Kai , Mukherjee Payal , Crook Jeremy Micah , Wallace Gordon George , Klein Travis Jacob , Clark Jonathan Robert
Published: October 2022

Free flap surgery is currently the only successful method used by surgeons to reconstruct critical-sized defects of the jaw, and is commonly used in patients who have had bony lesions excised due to oral cancer, trauma, infection or necrosis. However, donor site morbidity remains a significant flaw of this strategy. Various biomaterials have been under investigation in search of a suitable alternative for segmental mandibular defect reconstruction. Hydrogels are group of biomaterials that have shown their potential in various tissue engineering applications, including bone regeneration, both through in vitro and in vivo pre-clinical animal trials. This review discusses different types of hydrogels, their fabrication techniques, 3D printing, their potential for bone regeneration, outcomes, and the limitations of various hydrogels in preclinical models for bone tissue engineering. This review also proposes a modified technique utilizing the potential of hydrogels combined with scaffolds and cells for efficient reconstruction of mandibular segmental defects.
Polyelectrolytes for Enzyme Immobilization and the Regulation of Their Properties
Authors: Muronetz Vladimir I. , Pozdyshev Denis V. , Semenyuk Pavel I.
Published: October 2022

In this review, we considered aspects related to the application of polyelectrolytes, primarily synthetic polyanions and polycations, to immobilize enzymes and regulate their properties. We mainly focused on the description of works in which polyelectrolytes were used to create complex and unusual systems (self-regulated enzyme–polyelectrolyte complexes, artificial chaperones, polyelectrolyte brushes, layer-by-layer immobilization and others). These works represent the field of “smart polymers”, whilst the trivial use of charged polymers as carriers for adsorption or covalent immobilization of proteins is beyond the scope of this short review. In addition, we have included a section on the molecular modeling of interactions between proteins and polyelectrolytes, as modeling the binding of proteins with a strictly defined, and already known, spatial structure, to disordered polymeric molecules has its own unique characteristics.
Manufacture and Characterization of Recycled Polypropylene and Olive Pits Biocomposites
Authors: Jurado-Contreras Sofía , Navas-Martos Francisco J. , Rodríguez-Liébana José A. , Moya Alberto J. , La Rubia M. Dolores
Published: October 2022

The present work studies the use of olive pit (OP) as a reinforcement in the manufacture of composites based on a post-consumer recycled polypropylene (rPP). In this way, it is feasible to provide added value from olive pits, a by-product resulting from the olive industry operations, while promoting the circular economy and reducing the use of fossil-based polymers. For this purpose, suitable samples were manufactured using 25 wt% and 40 wt% of OP. Additionally, the effect of incorporating additives was studied: (a) a process control additive (PA), and (b) a coupling agent of maleic anhydride grafted polypropylene (MAPP). The results showed an improvement in Young’s and flexural modulus with the OP addition. The incorporation of PA did not present any significant improvement in the properties of the materials, nevertheless it facilitated the biocomposite manufacturing process. As for the coupling agent, it significantly improved the mechanical properties, achieving the best results with the addition of the two types of additives and 40 wt% of OP. Moreover, the thermal properties were maintained, and there was an increase in crystallinity in all composites compared to rPP. According to the results of the fracture surface analysis, the coupling agent improves reinforcement-polymer matrix cohesion.
Study of Carbon Matrix Composite as Wear-Resistant Plate Material on Improving Wear Resistance and Mixing Effect in Mixing Process
Authors: Pan Yiren , Chen Yihui , Pan Yi , Xue Junxiu , Han Wenwen , Bian Huiguang
Published: October 2022

Silica and carbon black are the most important reinforcing systems in rubber formula. In the process of continuous optimization of the formula, silica gradually replaces carbon black by its characteristics. In view of the wear problem of the components of the mixer chamber caused by the increase in the proportion of silica in the formula, this research applied carbon matrix composite (CMC) materials to wear-resistant plate materials, and compared them with common wear-resistant (CWR) plate materials to explore the impact of replacing CWR plate with CMC on improving wear resistance and mixing effect. The results showed that compared with the CWR plate, CMC wear-resistant plate showed characteristics of a high friction coefficient and low wear rate (reduced by about 23%) in the mixing process of silica compound. However, the friction behavior of carbon black compound and carbon matrix composite wear-resistant plate showed an opposite trend, where the friction coefficient and wear rate increased simultaneously, especially the wear rate that increased by about 35%. The main reasons for the experimental results were related to the characteristics, elemental composition and surface morphology of carbon matrix composite, silica and carbon black. The experimental results also indicated that the carbon matrix composite wear-resistant plate is more suitable for a silica mixing process, and the increasing friction coefficient with decreasing wear rate of wear-resistant plate can further improve the importance of effective friction in mixing and prolonging the service life of wear-resistant plate.
Molecular Simulation of Electron Traps in Epoxy Resin/Graphene Oxide Nanocomposites
Authors: Zhang Xuanning , Xu Hao , Liang Yanyu , Chen Geng , Wu Shaocong , Hao Guohui , Tu Youping , Wang Cong , Xu Yongsheng , Ruan Haoou
Published: October 2022

Trapped space charges in epoxy composite distort the electric field, which will induce the failure of the insulation system, and nano graphene oxide may inhibit the curing behavior of epoxy resin matrix. This paper analyzes how the two interfaces affect the electron traps of epoxy resin/graphene oxide systems with different nanofiller contents. The electron affinity energy of epoxy resin matrix and nano filler molecules in the epoxy resin/graphene oxide system is calculated based on quantum chemistry. It is found that nano graphene oxide has a strong electron affinity energy and is easier to capture electrons. Then the influence of the interface formed by the epoxy resin matrix and the nano graphene oxide on the electron transfer ability is calculated. The epoxy resin matrix contains the electron transfer ability of interfaces formed by nano graphene oxide and the molecular chain is different from that of unreacted molecules. The results can provide a reference for the modification of epoxy resin/graphene oxide nanocomposites.
A Methodology to Obtain the Accurate RVEs by a Multiscale Numerical Simulation of the 3D Braiding Process
Authors: Zhou Wei , Wang Hui , Chen Yizhe , Wang Yaoyao
Published: October 2022

To accurately evaluate the mechanical performance of three-dimensional (3D) braiding composites, it is essential to consider the braiding process and generate realistic representative volume element (RVE) structures. An efficient simulation methodology based on truss elements was used to simulate the 3D four-directional (3D4D) braiding process utilizing the finite element method (FEM) on the macroscale. The goal was to obtain the spatial trajectories of yarns and establish the relationship between the braiding parameters and the preform structure. Based on the initial yarn topology, the yarns were discretized as bundles of virtual sub-yarns. Then, a temperature drop simulation using hybrid elements was implemented to deform the yarn cross-section and obtain the interior, surface, and corner cells on the mesoscale. The simulation results show good agreement with the experiment. A parametric study was deployed to identify the effect of the model input parameters on the computation cost and accuracy. Furthermore, the approach applies to the other braiding processes, such as the cylindrical braiding composite.
Water−Processed Organic Solar Cell with Efficiency Exceeding 11%
Authors: Xie Chen , Liang Songqiang , Zhang Guangye , Li Shunpu
Published: October 2022

Water processing is an ideal strategy for the ecofriendly fabrication of organic photovoltaics (OPVs) and exhibits a strong market−driven demand. Here, we report a state−of−the−art active material, namely PM6:BTP−eC9, for the synthesis of water−borne nanoparticle (NP) dispersion towards ecofriendly OPV fabrication. The surfactant−stripping technique, combined with a poloxamer, facilitates purification and eliminates excess surfactant in water−dispersed organic semiconducting NPs. The introduction of 1,8−diiodooctane (DIO) for the synthesis of surfactant−stripped NP (ssNP) further promotes a percolated microstructure of the polymer and NFA in each ssNP, yielding water−processed OPVs with a record efficiency of over 11%. The use of an additive during water−borne ssNP synthesis is a promising strategy for morphology optimization in NP OPVs. It is believed that the findings in this work will engender more research interest and effort relating to water−processing in preparation of the industrial production of OPVs.
Preparation of Thermosensitive Fluorescent Polyacrylamide Nanofiber Membrane and Visual Temperature Sensing
Authors: Tao Xuejiao , Dai Zhao , Ma Yue , Li Nan
Published: October 2022

Fluorescent fibers are capable of discoloration behavior under special light sources, showing great potential for applications in biomedicine, environmental monitoring, heavy-metal-ion detaction, and anti-counterfeiting. In the current paper, temperature-sensitive fluorescent poly-acrylamide (PAM) nanofiber (AuNCs@PAM NF) membranes are prepared by mixing red fluorescent gold nanoclusters (AuNCs) synthesized in-house with PAM using the electrospinning technique. The AuNCs@PAM nanofibers obtained using this method present excellent morphology, and the AuNCs are uniformly dispersed in the fibers. The average diameter of the AuNCs@PAM NFs is 298 nm, and the diameter of AuNCs doped in the fibers is approximately 2.1 nm. Furthermore, the AuNCs@PAM NF films present excellent fluorescence and temperature-sensitive performance between 15 and 65 degrees. While under the 365 nm UV light source, the fiber film changes from white to red; this discoloration behavior weakens with the increase in temperature, and changes from deep to light red. Therefore, the approximate temperature can be identified using the color change, and a visual temperature-sensing effect can be achieved. The dual functions of temperature-sensitivity and fluorescent properties improve the scientificity and safety of nanofibers in the use of anti-counterfeiting technology.
Electrical Discharge Coating a Potential Surface Engineering Technique: A State of the Art
Authors: Tyagi Rashi , Mandal Amitava , Das Alok Kumar , Tripathi Ashutosh , Prakash Chander , Campilho Raul , Saxena Kuldeep K.
Published: October 2022

Electrical discharge coating (EDC) process is used to deposit material on workpiece surface from sacrificial or green compact tool electrode in an electrical discharge machine. The paper presents the mechanism of EDC using green compact electrode and powder mixed dielectric methods. The tool electrode material, electrode size, process parameters, and type of dielectrics can directly affect the surface integrity of workpiece. Here, a process map of EDC as a function of process parameters, its classification, advantages, and applications for a wide range of engineering materials offers a proper template for the evaluation of coating phenomena. This study shows that EDC is an economic process as compared to other costlier techniques. Additionally, the effect of various EDM and EDC parameters on surface integrity and tribological behavior of deposited coatings is studied with their pros and cons. Finally, the current research trends of EDC and its challenges are elaborated.
Temperature Prediction Model for a Regenerative Aluminum Smelting Furnace by a Just-in-Time Learning-Based Triple-Weighted Regularized Extreme Learning Machine
Authors: Chen Xingyu , Dai Jiayang , Luo Yasong
Published: October 2022

In a regenerative aluminum smelting furnace, real-time liquid aluminum temperature measurements are essential for process control. However, it is often very expensive to achieve accurate temperature measurements. To address this issue, a just-in-time learning-based triple-weighted regularized extreme learning machine (JITL-TWRELM) soft sensor modeling method is proposed for liquid aluminum temperature prediction. In this method, a weighted JITL method (WJITL) is adopted for updating the online local models to deal with the process time-varying problem. Moreover, a regularized extreme learning machine model considering both the sample similarities and the variable correlations was established as the local modeling method. The effectiveness of the proposed method is demonstrated in an industrial aluminum smelting process. The results show that the proposed method can meet the requirements of prediction accuracy of the regenerative aluminum smelting furnace.
Preliminary Study on Size Effect of Fractured Rock Mass with Sand Powder 3D Printing
Authors: Wang Wenhai , Zhao Yang , Jiang Lishuai , Zuo Jiacheng , Liu Guangsheng , Mitri Hani S.
Published: October 2022

The size effect has a significant effect on the mechanical behavior of rock, thereby fundamentally influencing the stability of rock excavations. The main challenge associated with the experimental research on the size effect of fractured rock mass lies in the difficulty of specimen preparation to represent the influence of size and fracture on the mechanical behavior of the rock material. In order to preliminarily explore the feasibility of 3D printing technology in the field of rock mechanics, fractured rock specimens of different sizes and different fracture characteristics were produced using sand powder 3D printing technology. The uniaxial compression test was combined with the digital image correlation method (DIC) technology to study the influence of the size effect on the mechanical properties and deformation and failure of different fractured specimens. The research finds that: (1) The elastoplastic mechanical characteristics of the sand powder 3D printed specimens are similar to soft rock. Specimen size and fracture angle have significant effects on the mechanical properties of specimens. Under different fracture conditions, the uniaxial compressive strength (UCS) and Elasticity Modulus of sand powder 3D specimens should be decreased with the increase of the specimen size, and the size effect has different influences on the specimens with different fracture characteristics. (2) Under different fracture conditions, the crack initiation position and failure mode of specimens of various sizes are affected by the fracture inclination to varying degrees. (3) The size effect of fractured rock mass is closely related to the defect level inside the rock mass. The size effect originates from the heterogeneity inside the material. The research results verify the feasibility of applying sand powder 3D printing technology to study the size effect of fractured rock masses and provide an innovative test method for the size effect test study. Preliminary exploration of the size effect of fractured rock masses provides a powerful reference for related research in this field. The study proves the feasibility of applying sand powder 3D printing technology in similar rock mechanics tests and contributes to understanding the size effect of a fractured rock mass.
How to (Not) Make a Perovskite Solar Panel: A Step-by-Step Process
Authors: Castriotta Luigi Angelo , Leonardi Enrico
Published: October 2022

To date, scientific research on perovskite solar cells (PSCs) and modules (PSMs) has been carried out for more than 10 years. What is still missing in the market potential of this technology is a complete description of the materials needed to connect and fabricate PSMs in order to build a perovskite solar panel. Starting from the state-of-the-art perovskite solar modules, the material and design optimization using different substrates and architecture types, and ending in the lamination of the panel, this work focusses on the study of the feasibility of the fabrication of a perovskite solar panel. A complete description of all steps required will be provided in detail.
Experimental and Numerical Studies of Fine Quartz Single-Particle Sedimentation Based on Particle Morphology
Authors: Liu Chunfu , Lv Kai , Liu Lingyun , Chen Jun , Ren Bao , Bai Xuejie , Min Fanfei
Published: October 2022

The sedimentation characteristics of quartz particles affect their separation and settling dehydration processes. Particle morphology determines the sedimentation equilibrium velocity. In this paper, the sedimentation of a single quartz particle is characterized by employing experimental and CFD-DEM approaches. SEM served to examine quartz particles measuring 30–500 μm, and they exhibited flaky–blocky morphologies with an average long–middle axis ratio of 1.6. Consistent with the SEM-detected morphological features of the quartz particles, suggested here is a simpler drag coefficient model, followed by verification of the model with experimental data. The results show that the velocity of a quartz particle in the non-settling direction had a fluctuation of ±0.2 mm/s. The fluctuation reached 0.4 mm/s at varying settlement release angles. The order in which the particles reached sedimentation equilibrium velocity during the settlement process was double-cone, single-cone, and square when the initial velocity was greater than sedimentation equilibrium velocity. Furthermore, the long–middle axis ratio of quartz particles diminished as their equilibrium sedimentation velocities rose. Given that the quartz particles ranged from 30 to 50 μm in size, the long–middle axis ratio wielded no discernible effect on the sedimentation equilibrium velocity.
Zero-Waste Watermelon Production through Nontraditional Rind Flour: Multiobjective Optimization of the Fabrication Process
Authors: Capossio Juan Pablo , Fabani María Paula , Román María Celia , Zhang Xin , Baeyens Jan , Rodriguez Rosa , Mazza Germán
Published: October 2022

Watermelon is a fruit produced around the world. Unfortunately, about half of it—the rind—is usually discarded as waste. To transform such waste into a useful product like flour, a thermal treatment is needed. The drying temperature for the rind that produces flour with the best characteristics is most important. A multiobjective optimization (MOO) procedure was applied to define the optimum drying temperature for the rind flour fabrication to be used in bakery products. A neural network model of the fabrication process was developed with the drying temperature as input and five process indicators as outputs. The group of process indicators comprised acidity, pH, water-holding capacity (WHC), oil-holding capacity (OHC), and batch time. Those indicators represent conflicting objectives that are to be balanced by the MOO procedure using the weighted distance method. The MOO process showed that the temperature interval from 67.3 °C to 73.1 °C holds the compromise solutions for the conflicting indicators based on the stakeholder’s preferences. Optimum indicator were 0.12–0.19 g malic acid/100 g dwb (acidity), 5.7–5.8 (pH), 8.93–9.08 g H2O/g dwb (WHC), 1.46–1.56 g oil/g dwb (OHC), and 128–139 min (drying time).
Gastroprotective, Biochemical and Acute Toxicity Effects of Papaver decaisnei against Ethanol-Induced Gastric Ulcers in Rats
Authors: Jabbar Ahmed Aj. , Abdullah Fuad O. , Abdoulrahman Kamaran , Galali Yaseen , Ibrahim Ibrahim Abdel Aziz , Alzahrani Abdullah R. , Hassan Rawaz Rizgar
Published: October 2022

Papaver decaisnei (P. decaisnei) has been used as folkloric medicine for many health issues including gastric problems. The current study investigates the gastroprotective roles of P. decaisnei against ethanol-induced ulcers in rodents. Sprague Dawley rats (30) were separated into five groups: the normal group (G1) and the ulcer control group (G2) were orally administered 0.5% carboxymethylcellulose (CMC); the reference group (G3) was administered 20 mg/kg of Omeprazole; two experimental groups were fed with 200 mg/kg (G4) and 400 mg/kg (G5) of the P. decaisnei extract (PDE), respectively. Next, the rats were given absolute ethanol and sacrificed for the analysis of the gastric mucosal injury through microscopic, enzymatic, histologic, and immunohistochemistry assays. The ulcer controls showed significant superficial hemorrhagic gastric mucosal lesions, with a decreased gastric wall mucus and edema production, whereas fewer were found for the reference and plant-treated rats. Furthermore, the PDE pre-treated rats had a significantly reduced the periodic acid-Schiff (PAS) staining intensity, produced the upregulation of the HSP70 protein, and the downregulation of the Bax protein expressions in the stomach epithelium. P. decaisnei displayed a significant role in the upregulation of endogenous antioxidant enzymes (SOD, CAT, and PGE2), significantly reduced malondialdehyde (MDA), TNF-a, IL-6, and upraised the IL-10 levels. Based on the positive impacts, the PDE can be proposed as the protective/treatment agent against gastric ulcers and stomach lesions.
Human-Health and Environmental Risks of Heavy Metal Contamination in Soil and Groundwater at a Riverside Site, China
Authors: Luo Dongyuan , Liang Yuan , Wu Hao , Li Shudi , He Yaoye , Du Junyan , Chen Xixi , Pu Shengyan
Published: October 2022

The contaminated site is considered a high-risk pollution source due to the accumulation of industrial waste and wastewater, which affects the soil and groundwater environment. In this study, through soil and groundwater investigation, we outlined the characteristics of heavy metal contamination in the soil and groundwater of the contaminated site, assessed the health risk of the contaminated site to humans, and established a numerical model to predict the ecological and environmental risks of the site. The results of the study showed that the maximum contamination concentration of pollutants (lead, arsenic, cadmium) in the soil all exceeded the Chinese environmental standard (GB36600-2018, Grade II), that the maximum contamination concentration (cadmium, Cd) of the groundwater exceeded the Chinese environmental standard (GB14848–2017, Grade IV), and that the heavy metal pollution was mainly concentrated in the production area of the site and the waste-residue stockpiles. The total carcinogenic risk and non-carcinogenic hazard quotient of the site’s soil heavy metal contaminants exceed the human acceptable limit, and there is a human health risk. However, the groundwater in the area where the site is located is prohibited from exploitation, and there is no volatility of the contaminants and no exposure pathway to the groundwater, so there is no risk to human health. The simulation prediction results show that, with the passage of time, the site groundwater pollutants as a whole migrate from south to north, affecting the northern surface water bodies after about 12 years, and there is a high ecological and environmental risk. The above findings provide a scientific basis for the study of the soil and groundwater at the riverside contaminated site.
Disassembly Sequence Planning for Green Remanufacturing Using an Improved Whale Optimisation Algorithm
Authors: Yu Dexin , Zhang Xuesong , Tian Guangdong , Jiang Zhigang , Liu Zhiming , Qiang Tiangang , Zhan Changshu
Published: October 2022

Currently, practical optimisation models and intelligent solution algorithms for solving disassembly sequence planning are attracting more and more attention. Based on the importance of energy efficiency in product disassembly and the trend toward green remanufacturing, this paper proposes a new optimisation model for the energy-efficient disassembly sequence planning. The minimum energy consumption is used as the evaluation criterion for disassembly efficiency, so as to minimise the energy consumption during the dismantling process. As the proposed model is a complex optimization problem, called NP-hard, this study develops a new extension of the whale optimisation algorithm to allow it to solve discrete problems. The whale optimisation algorithm is a recently developed and successful meta-heuristic algorithm inspired by the behaviour of whales rounding up their prey. We have improved the whale optimisation algorithm for predation behaviour and added a local search strategy to improve its performance. The proposed algorithm is validated with a worm reducer example and compared with other state-of-the-art and recent metaheuristics. Finally, the results confirm the high solution quality and efficiency of the proposed improved whale algorithm.
Effects of Calcium Sulfate and Chitosan on Textural Modification and Microstructure of Tofu Made from Lentils (Lens culinaris)
Authors: Jao Cheng-Hsun , Lin Chieh-Yi , Chen Chao-Jung , Hsieh Jung-Feng
Published: October 2022

This study investigated calcium sulfate and chitosan on the textural modification and microstructure of tofu made from lentils. The addition of varying amounts of calcium sulfate (0–12 mM) and chitosan (0–1.0%) into lentil milk could affect the gel properties of lentil-based tofu. The gel properties, including the hardness and cohesiveness, of lentil-based tofu significantly increased with the addition of 12 mM calcium sulfate, exhibiting a slightly discontinuous network structure and a slightly regular pore network. However, the gel properties including hardness and cohesiveness significantly decreased with the addition of 1.0% chitosan, presenting a slightly continuous network structure with pores. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that the aggregation of the vicilin, legumin acidic unit and legumin basic unit proteins in lentil milk was induced both by 12 mM calcium sulfate and 1.0% chitosan. Our results suggested that calcium sulfate and chitosan could affect the gel properties, such as hardness and cohesiveness, of lentil-based tofu. Therefore, calcium sulfate and chitosan can be used as practical food additives for the development of texture-modified lentil-based tofu.
Nonstationary Process Monitoring Based on Alternating Conditional Expectation and Cointegration Analysis
Authors: Rao Jingzhi , Ji Cheng , Wen Jiatao , Wang Jingde , Sun Wei
Published: October 2022

Traditional multivariate statistical methods, which are often used to monitor stationary processes, are not applicable to nonstationary processes. Cointegration analysis (CA) is considered an effective method to deal with nonstationary variables. If there is a cointegration relationship among the nonstationary series in the system, it indicates that a stable long-term dynamic equilibrium relationship exists among these variables. However, due to the complexity of modern industrial processes, there are nonlinear relations between variables, which are not considered by the traditional linear cointegration theory. Alternating conditional expectation (ACE) can perform nonlinear transformation on these variables to maximize the linear correlation of the transformed variables. It will be helpful to deal with the nonlinear relations by modeling with transformed variables. In this work, a new monitoring strategy based on ACE and CA is proposed. The data are first transformed by an ACE algorithm, CA is performed after that, and then monitoring statistics are calculated to determine whether the system is faulty. The strategy is applied to the monitoring of a simulation case and a catalytic reforming unit in a petrochemical company. The results show that the strategy can realize the monitoring of nonstationary process, with a higher fault detection rate and a lower false alarm rate compared with the monitoring strategy based on traditional cointegration theory.
Valorization of Lignin and Its Derivatives Using Yeast
Authors: Putra Filemon Jalu Nusantara , Kahar Prihardi , Kondo Akihiko , Ogino Chiaki
Published: October 2022

As the third most plentiful biopolymer after other lignocellulosic derivates such as cellulose and hemicellulose, lignin carries abundant potential as a substitute for petroleum-based products. However, the efficient, practical, value-added product valorization of lignin remains quite challenging. Although several studies have reviewed the valorization of lignin by microorganisms, this present review covers recent studies on the valorization of lignin by employing yeast to obtain products such as single-cell oils (SCOs), enzymes, and other chemical compounds. The use of yeasts has been found to be suitable for the biological conversion of lignin and might provide new insights for future research to develop a yeast strain for lignin to produce other valuable chemical compounds.
Transient Characteristics of Three-Dimensional Flow in a Centrifugal Impeller Perturbed by Simple Pre-Swirl Inflow
Authors: Wang Ze , Zhang Wei
Published: October 2022

The pre-swirl inflow generated by guide vanes could improve the hydrodynamic performances of centrifugal pumps as long as the inflow matches the patterns of internal flow of the impeller. In this work, we present a numerical investigation on the internal flow in a centrifugal impeller subjected to inflow artificially constructed with simple pre-swirling; unsteady Reynolds-Averaged Navier-Stokes (URANS) simulations are performed at the designed flow rate with five values of rotating velocity of the inflow, i.e., Urot/Uref = −0.5, −0.3, 0.0, 0.3 and 0.5, where Urot and Uref denote the rotating and normal velocity component at the entrance of the inflow tube, respectively. The primary objective of this work is to reveal the three-dimensional characteristics of internal flow of the impeller as influenced by the superimposed pre-swirl inflow, and to identify the propagation of inflow within the impeller. The numerical data are presented and analyzed in terms of the streamline fields, the distributions of various velocity components along the circumferential and axial directions, the pressure distribution and limiting streamlines on the surfaces of a blade. Numerical results reveal that separation occurs around the leading edge of the blades and occasionally at the trailing edge, and the internal flow is more uniform in the central region of the channels. A noticeable fluctuation of both radial and circumferential velocities is observed at the outlet of the impeller as it is subjected to counter-rotating inflow, and the greatest fluctuation is close to the hub instead of the middle channel and shroud as for the co-rotating inflow. The boundary layer flow of suction surface is more sensitive to the inflow; occasional small-scale separation bubble occurs on the suction surface around the leading edge for some blades, and reattachment of separated flow is reduced for the counter-rotating inflow.
Hybrid Methodology Based on Symmetrized Dot Pattern and Convolutional Neural Networks for Fault Diagnosis of Power Cables
Authors: Wang Meng-Hui , Sian Hong-Wei , Lu Shiue-Der
Published: October 2022

This study proposes a recognition method based on symmetrized dot pattern (SDP) analysis and convolutional neural network (CNN) for rapid and accurate diagnosis of insulation defect problems by detecting the partial discharge (PD) signals of XLPE power cables. First, a normal and three power cable models with different insulation defects are built. The PD signals resulting from power cable insulation defects are measured. The frequency and amplitude variations of PD signals from different defects are reflected by comprehensible images using the proposed SDP analysis method. The features of different power cable defects are presented. Finally, the feature image is trained and identified by CNN to achieve a power cable insulation fault diagnosis system. The experimental results show that the proposed method could accurately diagnose the fault types of power cable insulation defects with a recognition accuracy of 98%. The proposed method is characterized by a short detection time and high diagnostic accuracy. It can effectively detect the power cable PD to identify the fault type of the insulation defect.
Physical and Chemical Regularities of Phosphorus and Beryllium Recovery by the Sorbents Based on Acrylic Fiber Impregnated by Iron Hydroxide (III)
Authors: Bezhin Nikolay A. , Frolova Mariya A. , Kozlovskaia Ol’ga N. , Slizchenko Evgeniy V. , Shibetskaia Iuliia G. , Tananaev Ivan G.
Published: October 2022

The paper investigates the physicochemical regularities (kinetics and isotherm) of phosphorus and beryllium recovery by sorbents based on polyacrylonitrile (PAN) fiber and Fe(OH)3 obtained by various methods: PAN or pre-hydrolyzed PAN with precipitation of FeCl3 with ammonia, using ready-made or electrochemically generated Na2FeO4, pre-hydrolyzed PAN treated with an alkaline solution of Na2FeO4, as well as their comparison with granular aluminum oxide. The Langmuir, Freudlich and Dubinin–Radushkevich models show high performance of materials for sorption of stable P and Be used as tracers for the release of 7Be, 32P, and 33P from seawater. The obtained kinetic data are processed using kinetic models of intraparticle diffusion and the pseudo-first-order, pseudo-second-order, and Elovich models. Optimal conditions for obtaining sorbents are established, namely, the effect of NaOH concentration at the stages of preparation on the properties of sorbents based on the PAN fiber and Fe(OH)3 obtained by various methods.
Study of Technological Process of Fermentation of Molasses Vinasse in Biogas Plants
Authors: Romaniuk Waclaw , Rogovskii Ivan , Polishchuk Victor , Titova Liudmyla , Borek Kinga , Shvorov Serhiy , Roman Kamil , Solomka Oleksiy , Tarasenko Svetlana , Didur Volodimir , Biletskii Victor
Published: October 2022

The volume of ethanol production waste—molasses waste in Ukraine—reaches up to 4 million m3 per year. It is not easy to dispose of and is polluting the environment. Currently, the development of an effective technology for using molasses in biogas plants to obtain energy gas—biogas—is an urgent problem. The purpose of our work is to determine the rational volume of loading molasses bard into the methane tank in a quasi-continuous mode to obtain the maximum volume of biogas. To achieve this goal, the following experimental studies were carried out: mono-fermentation of molasses and combined fermentation of cattle manure and molasses on a laboratory biogas plant in a periodic mode; on the basis of the obtained laboratory studies, a special simulation model of biogas output during the quasi-continuous fermentation of substrates was established and the amount of molasses added to obtain the maximum biogas output was determined. The maximum output of biogas under the periodic system of loading the methane tank when adding 10.5% molasses to cattle manure is 1.462 l/(h kg DOM); when adding 26.1% molasses to cattle manure, it is 3.594 l/(h kg DOM). In order to increase the yield of biogas, it is advisable to add molasses in the amount of 30% of the volume of the substrate to the substrate based on cattle manure, which allows the discounted payback period of the biogas plant to be reduced to 1.2 years.
Differential Response of Soil Microbial Community Structure in Coal Mining Areas during Different Ecological Restoration Processes
Authors: Guo Yangnan , Wu Junlong , Yu Yan
Published: October 2022

Micro-organisms play important roles in promoting soil ecosystem restoration, but much of the current research has been limited to changes in microbial community structure in general, and little is known regarding the more sensitive and indicative microbial structures or the responses of microbial diversity to environmental change. In this study, based on high-throughput sequencing and molecular ecological network analyses, the structural characteristics of bacterial communities were investigated in response to four different ecological restoration modes in a coal mining subsidence area located in northwest China. The results showed that among soil nutrients, nitrate-nitrogen and fast-acting potassium were the most strongly associated with microbial community structure under different ecological restoration types. Proteobacteria, Actinobacteria, and Acidobacteria were identified as important phyla regarding network connectivity and structural composition. The central natural recovery zone was found to have the smallest network size and low complexity, but high modularity and good microbial community stability. Contrastingly, a highly complex molecular ecological network of soils in the photovoltaic economic zone existed beneath the photovoltaic modules, although no key species, strong bacterial competition, poor resistance to disturbance, and a significant increase in the relative abundance of Gemmatimonadetes were found. Furthermore, the reclamation zone had the highest soil nutrient content, the most complex network structure, and the most key and indicator species; however, the ecological network was less stable and readily disturbed.
Optimizing the Geometric Parameters of a Stepped Labyrinth Seal to Minimize the Discharge Coefficient
Authors: Chun Ye Hwan , Ahn Joon
Published: October 2022

A series of numerical simulations were performed to study the discharge coefficient based on the geometric parameters of a stepped labyrinth seal that sealed the secondary flow path of a gas turbine. In contrast with straight-through seals, stepped labyrinth seals introduce additional geometrical parameters related to the steps. In this study, three shape variables were observed: step height (SH), position, and cavity width (CW). The sensitivity to the leakage flow of the shape variable in the stepped labyrinth seal was analyzed. The mechanism for improving the sealing performance of stepped labyrinth seals was investigated. The results indicated that the stepped labyrinth seal exhibited up to 17.9% higher leakage-suppression performance than the straight labyrinth seal. Seals with large discharge coefficients had a large vena contracta upstream of each tooth structure and a rapidly accelerated axial velocity in the radial direction. We could observe that the discharge coefficient changed according to the flow field in the cavity. The wall shear stress was sensitive to the SH but not to the CW or step position.
Bridging the Operational Efficiency Differences between Franchisors and Franchisees: A Metafrontier Approach
Authors: Kim Seung Beom , Choi Kanghwa
Published: October 2022

A franchise business is a contractual relationship in which the franchisor and franchisee should cooperate to promote sustainable growth of their franchise entities. However, it is still unclear whether the relationship between franchisees and franchisors is a principal–agent or a business partner sharing a business goal. Thus, this study is a first attempt to investigate the relationship between franchisees and franchises using metafrontier and bootstrap DEA from the perspective of efficiency. We measured the efficiency of coffee franchises in Korea, which have grown rapidly in recent years despite the COVID-19 pandemic. Based on the bootstrap DEA results, there was a statistically significant difference in efficiency between franchisors and franchisees under the variable return-to-scale assumption. While the main cause of inefficiency in premium coffee chains is attributed to scale inefficiency, most franchisees have pure technological inefficiency. Thus, coffee franchisees can improve the operational efficiency by adjusting their business scale and reallocating service resources. This study demonstrates tailored operational plans to improve the operational efficiency of premium and mainstream coffee franchises and offers strategic initiatives to decrease the difference in efficiency between franchisors and franchisees.
A Review of the Hydraulic Fracturing in Ductile Reservoirs: Theory, Simulation, and Experiment
Authors: Zhu Dawei , Han Guofeng , Zou Honglan , Cui Mingyue , Liang Chong , Yao Fei
Published: October 2022

The bottom-hole pressure of hydraulic fracturing in ductile reservoirs is much higher than that of the hydraulic fracturing simulation, and the fracture toughness inferred from the field data is 1–3 orders of magnitude higher than that measured in the laboratory. The rock apparent fracture toughness increases with the increase in the confining pressure. Excluding the influence of the fluid viscosity and the fluid lag on the apparent fracture toughness, the fracture process zone (FPZ) at the fracture tip can explain the orders of magnitude of difference in the apparent fracture toughness between the laboratory and the field. The fracture tip is passivated by plastic deformation, forming a wide and short hydraulic fracture. However, the size of the FPZ obtained in the laboratory is in the order of centimeters to decimeters, while an FPZ of 10 m magnitude is speculated in the field. The FPZ size is affected by the rock property, grain size, pore fluid, temperature, loading rate, and loading configuration. It is found that the FPZ has a size effect that tends to disappear when the rock specimen size reaches the scale of meters. However, this cannot fully explain the experience of hydraulic fracturing practice. The hydraulic fracturing behavior is also affected by the relation between the fracture toughness and the fracture length. The fracture behavior of type II and mixed type for the ductile rock is poorly understood. At present, the apparent fracture toughness model and the cohesive zone model (CZM) are the most suitable criteria for the fracture propagation in ductile reservoirs, but they cannot fully characterize the influence of the rock plastic deformation on the hydraulic fracturing. The elastic-plastic constitutive model needs to be used to characterize the stress–strain behavior in the hydraulic fracturing simulation, and the fracture propagation criteria suitable for ductile reservoirs also need to be developed.
Thermodynamic Characteristics Study with Pyrolysis Steam Coupled Multi-Stage Condensers
Authors: Bai Yong , Ma Yunfeng , Ke Changjun , Cheng Wang , Guo Guangyan , Zhao Peng , Cao Can , Liao Lifen , Yang Xuebo , Fan Zhongwei
Published: October 2022

A four-stage condensers in series system was adopted to solve the problems of insufficient condensation of high-temperature pyrolysis steam and difficulty in the classification and recovery of pyrolysis oil, where the internal fluids conducted countercurrent convection heat exchange. A steady-state physical and mathematical model of a single condenser was established to clarify the discipline of heat transfer between the internal fluids. Meanwhile, the model of pyrolysis steam coupled multi-stage condensers was proposed with the help of the model compound firstly. A numerical simulation was carried out and the results showed that when the number of condensers in series was four, the heat transfer process of the system reached saturation, and the heat exchange of the cold and hot fluids was completely realized, and it was of little significance to continue to connect more condensers in series for the condensation of pyrolysis steam. To quickly condense the hot fluid, the key was to increase the mass flow rate of the cold fluid in the first-stage condenser. Compared with the experimental values, the calculated values of hot fluid outlet temperature were not higher than 10%, indicating that the model was highly reliable.