bluuebunny/crossref_metadata_2025 huggingface dataset:
UVA Photocatalytic Ozonation of Water Contaminants
Authors: Beltrán F. J. , Gimeno O.
Published: July 2022

Two decades ago, a new advanced oxidation process (AOP) named photocatalytic ozonation emerged to improve the removal rates of water contaminants. The process is based on a synergism between both oxidation types that significantly increases the concentration of hydroxyl radicals by mainly improving the reduction process taking place on the conduction band of the catalyst. The radiation source extends from UVC to visible light. This chapter deals with this AOP, focusing on aspects related to contaminants (mainly pharmaceuticals) removal, mechanism and kinetics, and centers on the use of UVA radiation.
Catalytic Peroxone Process and the Coupled Processes
Authors: Guo Zhuang , Xie Yongbing , Cao Hongbin
Published: July 2022

The peroxone process proposed by Staehelin and Hoigne in 1982 was used to decompose water contaminants, relying on the reaction between O3 and H2O2 to produce hydroxyl radicals (˙OH). The superiority of this process lies in the rapid production of ˙OH and negligible secondary pollution, but the efficiency is highly dependent on the pH of the water matrix. Specifically, the peroxone process works efficiently under alkaline conditions but suffers from very poor performance in treating acidic wastewater. By the use of tailored catalysts, the established catalytic peroxone process overcomes such a difficulty and becomes an emerging topic of the field. This chapter deals with the catalytic peroxone process, especially the preparation methods, structures and properties of various catalysts and the catalytic mechanism. Following this, peroxone-coupled processes (e.g., with photolysis, photocatalysis, ultrasonication and plasma) that further improve the treatment efficiency of peroxone process were also introduced.
Catalytic Ozonation with Ultrasound
Authors: Zhao Lei
Published: July 2022

As an efficient process for the degradation of pollutants in water treatment, the combination process of ultrasound and ozone is investigated. In this chapter, the generation of ultrasound and typical reactors are introduced at first, and then the reactivity of compounds, reaction kinetics and influencing factors of the system of ultrasound and ozone are investigated. Meanwhile, the ultrasound and ozone can be combined with a variety of processes such as homogeneous and heterogeneous ozonation. In addition, the enhanced mechanism of the process in which the hydroxyl radical is the primary oxidative species and the reactive mechanism of hydroxyl radical with the pollutants are introduced.
Ozonation Nanobubble Technology
Authors: Shi Xiaonan , Marhaba Taha , Zhang Wen
Published: July 2022

This chapter introduces the fundamental principles of ozone nanobubble generation and current applications, as well as the limitations in practical applications. Nanobubbles (NBs) are an emerging research area that shows great potential for enhancing the mass transfer and reaction efficiency of many chemical processes including ozonation. NBs are ultrafine or small bubbles with a size or diameter typically smaller than 1 μm, which exhibit valuable characteristics (e.g. long residence times in water due to their low buoyancy and high stability against coalesces, collapse or burst). Particularly, NBs have a higher efficiency of mass transfer compared to bulk bubbles due to the high specific surface areas. Ozone NBs, a new form of dispersion in water, could potentially increase the longevity and stability of ozone as well as the effective dissolved ozone concentration compared to regular dissolved ozone. Ozone NBs generation and emerging applications are discussed to shed new light on the development of ozonation disinfection. Finally, future directions and research needs for commercialization are highlighted and summarized.
C(sp3)–H oxidation and chlorination catalysed by a bioinspired pincer iron(iii) complex
Authors: Han Jian , Tan Liming , Wan Yanjun , Li Gang , Anderson Stephen N.
Published: July 2022

A pincer iron(iii) catalyst for the oxidation and chlorination of C(sp3)–H bonds was developed.
Expression of concern: Synthesis of polyaniline–magnetite nanocomposites using swollen liquid crystal templates for magnetically separable dye adsorbent applications
Authors: Shore Andrew
Published: July 2022

Expression of concern for ‘Synthesis of polyaniline–magnetite nanocomposites using swollen liquid crystal templates for magnetically separable dye adsorbent applications’ by S. Dutt, T. Vats and P. F. Siril, New J. Chem., 2018, 42, 5709–5719, https://doi.org/10.1039/C7NJ04637E.
Photoacid-catalyzed acetalization of carbonyls with alcohols
Authors: Saway Jason , Pierre Abigail F. , Badillo Joseph J.
Published: July 2022

In this report, we demonstrate that visible light photoactivation of 6-bromo-2-naphthol facilitates the photoacid-catalyzed acetalization of carbonyls with alcohols.
Synthesis of N-alkoxy amines and hydroxylamines via the iridium-catalyzed transfer hydrogenation of oximes
Authors: Xia Yanping , Wang Sen , Miao Rui , Liao Jianhua , Ouyang Lu , Luo Renshi
Published: July 2022

An efficient and practical strategy for the construction of N-alkoxy amines and hydroxylamines through the corresponding oximes is described via an Ir-catalyzed acid-assisted system with high yields and a good substrate scope.
A new layered bidirectional equalizer based on a novel resonant voltage balance converter for the battery voltage active equalization of energy storage system
Authors: Wang Peng , Wei Yaoquan , Peng Qi , Wen Chunxue , Li Jianlin , Zhang Xiaoguang , Liu Shuo , Wei Qingxuan
Published: July 2022

In order to eliminate the impact of battery pack inconsistency on the cycle life and available capacity of the energy storage system and improve the balance speed, a layered bidirectional equalizer based on a novel resonant voltage balance converter is proposed. The equalizer is composed of bidirectional resonant converter circuits in series. One layer contains multiple balanced sub‐circuits based on bidirectional resonant converters, and the equalization thresholds of the balanced sub‐circuits of different layers are changed by designing different electrical parameters. The balance sub‐circuit of the bidirectional resonant converter proposed in this paper can realize the zero‐current turn‐on and turn‐off of the switches, which can effectively reduce the power loss of the equalizer, and the control system is simple, which improves the stability of the system; meanwhile, compared with other equalizers based on switched capacitor or switched inductance converters, the number of switching devices is greatly reduced, and the voltage balance speed is higher. The simulation and experimental results show that the equalizer can achieve a good balance of the battery terminal voltage during charging and discharging and standing state, and the equalization accuracy is higher, which verifies the correctness and effectiveness of the equalizer.
Endoscopic management of tumors of minor ampulla: a multicenter study
Authors: Khalyfa Ahamed A. , Ahsan Nayab , Inam Mahnoor , Ayub Kamran
Published: July 2022

Background and study aims Papillary and duodenal carcinoma are aggressive cancers with poor 5-year survival rates. Papillectomy is a well-established treatment for early-stage carcinoma of the major papilla. Tumors arising in the minor papilla are relatively rare and there is little research available on the endoscopic management of these tumors.

Patients and methods The purpose of this study was to establish the safety and efficacy of endoscopic papillectomy in the management of minor papillary tumors. A total of six patients undergoing ERCP for papillectomy for minor papillary tumor at four hospitals were included in this study over a period of 5 years.

Results Papillectomy was technically successful in all six patients. Pathology revealed adenoma in three patients, adenoma with high-grade dysplasia in one patient, carcinoma in one patient, and carcinoid tumor in one patient. For follow-up, one patient had an additional tumor identified at 2 years which was found to be a recurrence of the original adenoma. This patient was treated with repeat papillectomy with no further evidence of recurrence.

Conclusions In our pilot study, we demonstrate that endoscopic papillectomy appears safe and effective in the management of minor papillary tumors.
Limited Effects of SARS-CoV-2 Pandemic-related Lockdowns and Reduced Population Mobility on Preterm Birth Rates: A Secondary Analysis of Bavarian Obstetric Quality Parameters
from 2010 to 2020
Authors: Stumpfe Florian Matthias , Schneider Michael Oliver , Hein Alexander , Faschingbauer Florian , Kehl Sven , Hermanek Peter , Böhm Julian , Scharl Anton , Beckmann Matthias Wilhelm , Staerk Christian , Mayr Andreas
Published: July 2022

Introduction International studies on preterm birth rates during COVID-19 lockdowns report different results. This study examines preterm birth rates during lockdown periods and the
impact of the mobility changes of the population in Bavaria, Germany.

Material and Methods This is a secondary analysis of centrally collected data on preterm births in Bavaria from 2010 to 2020. Preterm births (< 37 weeks) in singleton and twin
pregnancies during two lockdowns were compared with corresponding periods in 2010 – 2019. Fisherʼs exact test was used to compare raw prevalence between groups. Potential effects of two
fixed lockdown periods and of variable changes in population mobility on preterm birth rates in 2020 were examined using additive logistic regression models, adjusting for long-term and
seasonal trends.

Results Unadjusted preterm birth rates in 2020 were significantly lower for singleton pregnancies during the two lockdown periods (Lockdown 1: 5.71% vs. 6.41%; OR 0.88; p < 0.001;
Lockdown 2: 5.71% vs. 6.60%; OR = 0.86; p < 0.001). However, these effects could not be confirmed after adjusting for long-term trends (Lockdown 1: adj. OR = 0.99; p = 0.73; Lockdown 2:
adj. OR = 0.96; p = 0.24). For twin pregnancies, differences during lockdown were less marked (Lockdown 1: 52.99% vs. 56.26%; OR = 0.88; p = 0.15; Lockdown 2: 58.06% vs. 58.91%; OR = 0.97;
p = 0.70). Reduced population mobility had no significant impact on preterm birth rates in singleton pregnancies (p = 0.14) but did have an impact on twin pregnancies (p = 0.02).

Conclusions Reduced preterm birth rates during both lockdown periods in 2020 were observed for singleton and twin pregnancies. However, these effects are reduced when adjusting for
long-term and seasonal trends. Reduced population mobility was associated with lower preterm birth rates in twin pregnancies.
Capturing, creating, and characterizing circulating tumor cells and clusters
Authors: Piccone Ashley
Published: July 2022

Microfluidic devices can aid in developing in vitro models and pave the way for liquid biopsy as a minimally invasive method for disease monitoring.
Therapeutic functions of astrocytes to treat α-synuclein pathology in Parkinson’s disease
Authors: Yang Yunseon , Song Jae-Jin , Choi Yu Ree , Kim Seong-hoon , Seok Min-Jong , Wulansari Noviana , Darsono Wahyu Handoko Wibowo , Kwon Oh-Chan , Chang Mi-Yoon , Park Sang Myun , Lee Sang-Hun
Published: July 2022

Intraneuronal inclusions of misfolded α-synuclein (α-syn) and prion-like spread of the pathologic α-syn contribute to progressive neuronal death in Parkinson’s disease (PD). Despite the pathologic significance, no efficient therapeutic intervention targeting α-synucleinopathy has been developed. In this study, we provide evidence that astrocytes, especially those cultured from the ventral midbrain (VM), show therapeutic potential to alleviate α-syn pathology in multiple in vitro and in vivo α-synucleinopathic models. Regulation of neuronal α-syn proteostasis underlies the therapeutic function of astrocytes. Specifically, VM-derived astrocytes inhibited neuronal α-syn aggregation and transmission in a paracrine manner by correcting not only intraneuronal oxidative and mitochondrial stresses but also extracellular inflammatory environments, in which α-syn proteins are prone to pathologic misfolding. The astrocyte-derived paracrine factors also promoted disassembly of extracellular α-syn aggregates. In addition to the aggregated form of α-syn, VM astrocytes reduced total α-syn protein loads both by actively scavenging extracellular α-syn fibrils and by a paracrine stimulation of neuronal autophagic clearance of α-syn. Transplantation of VM astrocytes into the midbrain of PD model mice alleviated α-syn pathology and protected the midbrain dopamine neurons from neurodegeneration. We further showed that cografting of VM astrocytes could be exploited in stem cell–based therapy for PD, in which host-to-graft transmission of α-syn pathology remains a critical concern for long-term cell therapeutic effects.
The durability of natural infection and vaccine-induced immunity against future infection by SARS-CoV-2
Authors: Townsend Jeffrey P. , Hassler Hayley B. , Sah Pratha , Galvani Alison P. , Dornburg Alex
Published: July 2022

The durability of vaccine-mediated immunity to SARS-CoV-2, the durations to breakthrough infection, and the optimal timings of booster vaccination are crucial knowledge for pandemic response. Here, we applied comparative evolutionary analyses to estimate the durability of immunity and the likelihood of breakthrough infections over time following vaccination by BNT162b2 (Pfizer-BioNTech), mRNA-1273 (Moderna), ChAdOx1 (Oxford-AstraZeneca), and Ad26.COV2.S (Johnson & Johnson/Janssen). We evaluated anti-Spike (S) immunoglobulin G (IgG) antibody levels elicited by each vaccine relative to natural infection. We estimated typical trajectories of waning and corresponding infection probabilities, providing the distribution of times to breakthrough infection for each vaccine under endemic conditions. Peak antibody levels elicited by messenger RNA (mRNA) vaccines mRNA-1273 and BNT1262b2 exceeded that of natural infection and are expected to typically yield more durable protection against breakthrough infections (median 29.6 mo; 5 to 95% quantiles 10.9 mo to 7.9 y) than natural infection (median 21.5 mo; 5 to 95% quantiles 3.5 mo to 7.1 y). Relative to mRNA-1273 and BNT1262b2, viral vector vaccines ChAdOx1 and Ad26.COV2.S exhibit similar peak anti-S IgG antibody responses to that from natural infection and are projected to yield lower, shorter-term protection against breakthrough infection (median 22.4 mo and 5 to 95% quantiles 4.3 mo to 7.2 y; and median 20.5 mo and 5 to 95% quantiles 2.6 mo to 7.0 y; respectively). These results leverage the tools from evolutionary biology to provide a quantitative basis for otherwise unknown parameters that are fundamental to public health policy decision-making.
High entropy alloy strengthening modelling
Authors: Zang Chengwei , Rivera-Díaz-del-Castillo Pedro E J
Published: July 2022

High entropy alloys (HEAs) have recently drawn attention due to their excellent mechanical properties across wide temperature ranges. This is attributed to phase stability and a wide variety of strengthening mechanisms in operation. Solid solution, precipitation, dislocation, grain-boundary, twin-boundary and phase-transformation strengthening have been reported to play an important role in controlling their mechanical properties. With a focus on yield strength, this paper reviews the different hardening mechanisms reported in the literature. Mathematical formulations and key constant for describing each mechanism are presented and discussed. A strengthening mechanism modelling strategy for HEA design is outlined.
Complex Er-doped selenium-based chalcogenides in the far-infrared region: a structural bonding arrangement study
Authors: Kumari Chandresh , Katyal S C , Chhoker Sandeep , Sharma Pankaj
Published: July 2022

Selenium-based chalcogenide glasses show tremendous infrared transmission in the 2–15 μm region, and these amorphous glasses could be easily formed into optical devices i.e. optical fibers and lenses, owing to their good thermo-mechanical properties. Even though the phonon energy for tellurium-based glasses is on the lower side, still, selenium-based glasses are worthwhile for mid to long-wavelength infrared emissions. Here, we have developed Er-doped selenium-based, Ge
17
Sb
8
Se
75−x

Er

x
where x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0, chalcogenides by conventional melting and quenching technique for possible mid to far-infrared applications. Far-infrared transmission spectra of the synthesized chalcogenides are obtained at room temperature in the spectral range of 35–450 cm−1. The bonding arrangements in the synthesized chalcogenides are investigated as a function of composition. It has been found that with the addition of Er content, the far-infrared transmission spectra shift toward the lower wavenumber side. The experimental results are correlated with the theoretically calculated parameters such as relative probability, bond energy, wave number, force constant etc. The obtained results provide insight into understanding the synthesized chalcogenides’ optical behavior, which is dynamic for designing the optical components operated in mid-infrared to far-infrared regions.
Superradiant pion clouds around primordial black holes
Authors: Ferraz Paulo B. , Kephart Thomas W. , Rosa João G.
Published: July 2022

We show that highly spinning primordial black holes of mass
M ∼ 1012 kg, potentially born in a matter-dominated era after
inflation, can produce clouds of pions in their vicinity via the
superradiant instability, with densities up to that of nuclear
matter. We discuss the electromagnetic signatures of this process,
via neutral pion decay and charged pion annihilation into photons,
computing in particular their contribution to the isotropic
gamma-ray background. This allows us to place upper bounds on the
abundance of such primordial black holes that are comparable to the
ones obtained from Hawking evaporation. We also discuss the
possibility of directly observing such clouds in high-redshift
superclusters.
Quantum kinetic theory of flux-carrying Brownian particles
Authors: Valido Antonio A
Published: July 2022

We develop the kinetic theory of the flux-carrying Brownian motion recently introduced in the context of open quantum systems. This model constitutes an effective description of two-dimensional dissipative particles violating both time-reversal and parity that is consistent with standard thermodynamics. By making use of an appropriate Breit–Wigner approximation, we derive the general form of its quantum kinetic equation for weak system-environment coupling. This encompasses the well-known Kramers equation of conventional Brownian motion as a particular instance. The influence of the underlying chiral symmetry is essentially twofold: the anomalous diffusive tensor picks up antisymmetric components, and the drift term has an additional contribution which plays the role of an environmental torque acting upon the system particles. These yield an unconventional fluid dynamics that is absent in the standard (two-dimensional) Brownian motion subject to an external magnetic field or an active torque. For instance, the quantum single-particle system displays a dissipationless vortex flow in sharp contrast with ordinary diffusive fluids. We also provide preliminary results concerning the relevant hydrodynamics quantities, including the fluid vorticity and the vorticity flux, for the dilute scenario near thermal equilibrium. In particular, the flux-carrying effects manifest as vorticity sources in the Kelvin’s circulation equation. Conversely, the energy kinetic density remains unchanged and the usual Boyle’s law is recovered up to a reformulation of the kinetic temperature.
Optimization of a Can Size Problem Using Real Encoded Chromosome in Genetic Algorithm
Authors: Ashraf M , Gola A , AlArjani A , Hasan F
Published: July 2022

One of the major drawback of Genetic Algorithm (GA) based solutions to many optimization problems is the difficulty to obtain convergence to an optimal solution. One of the possible reason for not obtaining good convergence is due to the improper encoding of chromosomes. Many techniques were proposed in some previous researches for improving the convergence of GA based solutions. However, no consideration regarding the role of chromosome encoding in achieving convergence and optimality both has been discussed in the past. In the present work, a can volume optimization problem is solved with the help of two types of chromosome encoding techniques that are proposed and evaluated in GA environment. First, based on single random gene selection and second based on mean value of genes of the encoded chromosome. A numerical example with an objective function and constraints has been solved and the results for each of the scheme is being discussed.
A Model for the Intelligent Supervision of Production for Industry 4.0
Authors: Klos S , Patalas-Maliszewska J , Tront D
Published: July 2022

Nowadays, the automation of production processes requires qualified engineering staff; unfortunately, such personnel are in very short supply in all EU countries. This article proposes a concept for a model for the intelligent supervision of production for Industry 4.0., the implementation of which will allow the demand for highly skilled engineering staff to be reduced within a company. An analysis of the literature, dedicated to manufacturing enterprises, regarding the intelligent supervision of production systems, is carried out in the article. It follows, therefore, that the Industry 4.0 concept assumes that mechanisms will be implemented, in production resources, in order to enable preventive measures to be taken, vis-à-vis breakdowns, failures and disruptions to the operation of devices. The need to develop a model for the intelligent supervision of production systems, in the face of challenges within the concept of Industry 4.0, is proposed. This model includes the following elements: (1) a configurator allowing devices to be selected for measuring production parameters, (2) a database for registering production system parameters, (3) Convolutional Neural Networks (CNN), as the prediction algorithm and (4) a knowledge-based structure, including operating procedures and good practices for preventing emergency situations, threats and excessive energy consumption in production systems. The usefulness of this model for predictive maintenance, safety and energy efficiency, vis-à-vis the use of production resources, as well as in support of middle management for decisions taken by employees, is described.
The use of random forests to support the decision-making process for sustainable manufacturing
Authors: Antosz K , Kozłowski E , Sęp J , Żabiński T
Published: July 2022

Today’s companies need to change the way they produce and consume goods to meet sustainability requirements. These companies are striving to increase production efficiency, while reducing the use of raw materials, reducing costs and reducing their impact on the environment. Intelligent decision support systems are an inseparable element supporting such action. The presented work the use the data mining method (random forests) to identify the parameters affecting the condition of the cutting blade is presented. The developed model was evaluated using indicators to assess the quality of classifications. The obtained results confirm the high quality of the predictive model. The proposed model can be used to support the decision-making process in determining the life of a cutting tool. This will reduce the consumption of raw materials and production waste, and thus reduce the company’s environmental impact, which is consistent with the assumptions of sustainable production.
Digital Twin-driven approach towards manufacturing processes support
Authors: Helman Joanna
Published: July 2022

Modern systems supporting production processes are undergoing significant changes, which involve challenges related to the digitization of processes. Decision making is becoming more and more dependent on the analysis of various types of data and information from the production process. The 4th Industrial Revolution forces the transition towards new technologies, innovation and digital models also in manufacturing operations. One of the phenomena of Industry 4.0 is Digital Twin, whereby it is possible to analyze and simulate real-time different production variants from the real environment without directly interfering with the actual production process. Thanks to the use of Digital Twin, it is possible to optimize manufacturing procedures, detect physical problems faster and make a decision about a process change with smaller risks to achieve a new higher level of productivity. This paper will introduce the theoretical aspects connected with Digital Twin-driven approach in smart manufacturing and will emphasize its potential towards the application of new-generation information technologies in industry and manufacturing. The systematic literature research will be focused on the analysis of different application areas of Digital Twin in the modern industry. This paper will specify and highlight how manufacturing processes can benefit from the use of the Digital Twin concept.
Digital system for sound sources location problem in multidimensional space using machine learning methods
Authors: Walczyński Maciej , Ruszkowski Piotr , Bozejko Wojciech
Published: July 2022

The issues presented in this work relate to the possibility of detecting the location of the sound source and its effectiveness in production conditions using recordings made with artificial head and processed with using an artificial neural networks. The use of an artificial head and artificial neural networks was motivated by an attempt to map human perception using available computer technology. The work attempts to map the features used for location human sources of sound through digital signal processing and machine learning. Artificial neural networks are commonly used, among others, in image recognition, where, using a camera or camera, the algorithm classifies objects in the image. Machine learning algorithms in addition allow for the implementation of self-learning speech or text recognition models. As part of the work, it was decided to localize the sound for a collection of fifteen different items sources relative to the head. To avoid duplicating similar measurements, the sound source was to the left of the artificial head. For signal processing and programming language was used to prepare the artificial neural network model Python with the Numpy numerical library, a library designed for signal processing Scipy, TensorFlow and Keras.
Application of Scheduling Systems in Smart Manufacturing
Authors: Olender-Skóra M , Gonet A
Published: July 2022

At the present time, where products are more and more often made for a specific customer, the production of such products requires more and more decisions to be made in the shortest possible time. This causes that solutions and methods are sought to support production planning and scheduling in such a dynamic environment of various variables. The problem concerns both the decision support system and the relevant data sets, on the basis of which schedules are generated. The article presents an algorithm related with generating schedules in the production planning system, as well as an application for supporting the process of decision making the purpose of which is choosing the best schedule from the set of available solutions. This is very important from the point of view of “product customization” and intelligent manufacturing.
Dispersion analysis of hydrogen released from a fuel cell electric vehicles with ventilations
Authors: Li Yuejuan , Hou Xulei , Qi Wei , Hong Zehui , Wang Cheng , zhang Bo , Wang Qiubo , Zhang Xiaolu
Published: July 2022

Hydrogen is one of most attractive clean energy and has been broadly used as fuel for vehicles. However, the accidental leakage of the hydrogen may cause fire and casualties. So, it is extremely important to have a good knowledge of the leaking hydrogen dispersion. This study focuses on the effect of vent amount, location and wind pattern on the distribution of leaked hydrogen using CFD models. The dispersion of high-pressure hydrogen horizontally released from a hydrogen fuel cell transit bus in an enclosure with multiple vents is simulated using CFD models. The results figure out an improvement in ventilation with two vents or forced wind imposed at the vents and the results also illustrate keeping distance between two vents makes the improvement much apparently. The hydrogen mass fraction at monitors closed to the vents that is imposed with the wind keeps low level. As a result, all these kinds of positions are not suggested to be the locations for installing the sensors.
Removal Mechanism of Abrasive Jet Polishing with a Novel Nozzle
Authors: Yuan Qiaoling , Chen Xun , Wen Donghui
Published: July 2022

In view of the high-precision and low-damage requirements for surface polishing of hard and brittle components, an abrasive jet polishing process using a novel nozzle with specifically designed shroud was proposed. The removal mechanism of abrasive jet polishing was investigated by simulating the jet flow in the interaction area of the nozzle shroud and workpiece. The simulation results indicate that the velocity of the abrasive jet increases greatly by the shroud and the direction of the jet is aligned almost parallel to the workpiece surface. With such a design, the normal force of the abrasive jet is minimized to reduce the impact damage of the workpiece surface. Further, the stabilized abrasive jet insures a smooth machining. The machining experiments were performed on the quartz glass component, a typical hard and brittle material. The results of the shrouded abrasive jet polishing experiments show that the material removal mainly relied on the shearing and scratching of the workpiece surface rather than the mechanical shock impacts, which is consistent with the simulation findings.
Application of a Digital Twin for Manufacturing Process Simulation
Authors: Olender-Skóra M , Banaś W
Published: July 2022

Due to the growing market demand and increasing customization of products, the enterprises have to increasingly adapt to the prevailing market conditions. However this adaption should be conducted with the lowest production costs and the best possible utilization of resources. One of the ideas, to obtain that, may be an attempt to implement the so called digitization and a digital twin for the enterprise. The article presents the possibilities of enterprise digitization and problems that the enterprises have to deal with, in order to better organize and plan the production process in the modern, dynamically changing environment.
Influence of guide rail error on machining accuracy and compensation method
Authors: Xi J P , Zhang C , Zhang L B
Published: July 2022

This paper introduces the guide rail error and analyses the influence of the guide rail error on the machine tool. Several common measuring and error compensation methods are introduced. To reduce the error of machine tool guide, researchers need to have a full understanding of it, and then take appropriate measures to reduce this error, so as to achieve the purpose of improving the machining accuracy. In this paper, through theoretical analysis, the variation trend of guide rail contour error is obtained, which is verified by laser interferometer, and the appropriate position is selected for error compensation. After the test verification, the test proves that the compensation method can effectively compensate the model rail error.
Study on the Motion Characteristics of Abrasive Media in Vibratory Finishing
Authors: Liu Wenwu , Wang Shuwen , Jiang Qifeng , Morgan Michael , Liu Xiaoxiao
Published: July 2022

In order to investigate the motion characteristics of the abrasive media in the vibratory finishing, the RecurDyn and EDEM coupled simulation method is employed. The simulation results show that the trajectories of the abrasive media are annular spiral motions in general, including a circular motion about the central axis of the vibratory finishing machine and an elliptical motion around the center of the media flow. The reliability of the RecurDyn-EDEM coupled simulation for the vibratory surface finishing process is validated by X-ray real-time detection, which has significance in better understanding of the motion characteristics of abrasive media and the optimal design of the vibratory surface finishing processes.
Analysis for the Process Planning of the Body Side Welding in Delmia
Authors: Dai Huaichu , Lv Gang , Huang Wenjin , Qin Qiang
Published: July 2022

Welding, as an important process for body-in-white (BIW), it should be taken into consideration in the automobile industry where the spot welding is often used. In order to validate the welding process of the whole welding line, the simulation process for the body side which is an important part of the BIW is discussed in the software Delmia according to the layout in AutoCAD which has been designed before. And then the establishment of model, the welding process and the specific working procedures are considered and discussed in the design stage to guarantee that the simulation process in Delmia can be carried on to validate whether the designed process can meet the working requirements. Additionally, the welding operation by multi-robots in a work station is analysed to verify that the number of robots and their positions are acceptable and they can reach working positions. Finally, the planning of the cycle time is obtained and then we can conclude that the designed welding process is feasible to guide the work in site.
Microstructural Design of the Cast Iron via Laser Hardening with Defocused Beam of the Continuous Wave CO2 Laser
Authors: Ahuir-Torres J.I. , Sharp M. , Bakradze N. , Batako A.D.L
Published: July 2022

The cast iron is widely used in mechanical parts due to its good properties, as damping, good fluidity, resistance to deformation, excellent machinability and low cost. However, the number of its applications are reduced because its low corrosion, wear and friction resistance. The microstructure of the metallic materials has high influence on these properties. Laser hardening can improve these properties via designing of the microstructure. The evaluation of the laser parameter influence on the microstructural features is vital for a correct design of the microstructure and therefore, good improvement of the metallic material properties. Although the various laser parameter influence has been analysed on sundry papers, the influence of the distance from focal point and scan speed in the laser hardening microstructures has been rarely evaluated in the literature. Thus, the influence of this parameter on the microstructures generated through laser hardening is the subject matter of this work. The experiments were carried out with continuous wave carbon dioxide laser on samples of ground cast iron. The atmosphere was air flow at 0.7MPa, the laser operated at 100W and the scan rates were 1mm/s and 5mm/s. The distances to focal point of the laser beams ranged from 0.0mm to 5.6mm. The microstructures of the samples were revealed via nital and evaluated with optical microscopy. This work shown that the microstructure of gray iron cast can be designed by mean of laser hardening. In addition, laser hardened zones had various microstructures (e.g. austenitic, martensitic, pearlite and dendritic). The type of the microstructures in laser treated zones was determined by distance from focal point and scan speed. Moreover, the width and the depth of the laser hardened zones were generally enlarged with the increasing of the distance from focal point. Furthermore, the laser irradiation at slow rates, i.e. 1mm/s, produced laser hardened zones larger than laser scan at 5mm/s. In future works, the hardness, wear and friction resistance of the laser hardened samples will be evaluated because the literature review indicates that austenitic and martensitic microstructures show high values of these properties.
Numerical simulations of Quasi-Static Fracture Behaviour of AISI 316 for Nuclear Transport packages
Authors: Angel Olivia , Rothwell Glynn , English Russell
Published: July 2022

Nuclear transport packages must pass stringent post-design safety tests before they can be licensed for use. Impact and thermal tests are designed to replicate the worst case conditions in the event of an accident, and often result in the failure of some materials. The outer construction of nuclear transport packages relies on AISI 316. Finite element (FE) models help demonstrate part of the testing required for the performance of nuclear transport packages. FE codes accurately predict the elastic-plastic response of materials up to the ultimate tensile strength. In this study, preliminary work of a series of 12 specimens are designed for numerical simulations using the FE code ABAQUS on AISI 316. The evolution of stress triaxiality during multiaxial loading conditions such as tensile, compressive, pure shear and combined loading conditions is used to further understand ductile fracture.
Dynamic simulation models as digital twins of logistics systems driven by data from multiple sources
Authors: Krenczyk D
Published: July 2022

In recent years, the development of manufacturing companies in the most dynamic industries, such as automotive, has been conditioned by the use of modern technologies, but also management concepts focused on quality and continuous improvement of processes and services. There was also a rapid increase in the level of production automation with a simultaneously growing level of flexibility in manufacturing systems, forced by the need to adapt the product to the customer’s needs (mass customization). These factors influenced the formation of a new concept for the development of industrial systems, referred to as Industry 4.0. It refers to production based on cyber-physical systems, integrating manufacturing, logistics, and distribution. One of the main components of an intelligent factory, based on cyber-physical systems, is the virtual equivalent of a real system in the form of the digital twin. Based on the feedback from the real system, a digital simulation supported by analytical software on the information platform is created. Dynamic simulation models should automatically adapt to changes in physical objects of the analysed system. Therefore, models of real objects reflecting their current state and logic of behaviour are required. The methods of automatic or semi-automatic generation of simulation models are the answer to these problems. They are based on approaches using data and information obtained from ERP/MES/CAD systems. In this paper, the proposed schemes for data exchange in the process of creation and simulation models and mapping of the dynamics of the actual system are shown.
Recycling-oriented analysis of domestic vacuum cleaner
Authors: Diakun J , Dostatni E , Rojek I , Rybacki P
Published: July 2022

A study of recyclability of a selected product, based on analyses conducted using an original application for the assessment of recyclability of products. The term ‘recycling’ has been defined and the role of recyclability in the process of eco-design specified. Some general recycling-oriented assessment methods have been discussed. The method used in the study, based on a recycling-oriented product model (RmW) and an agent-based system, has been described. The analysis has been applied to a domestic vacuum cleaner, considering the specificity of the industry. A model of the vacuum cleaner has been created in a 3D CAD system and extended with recyclability parameters to support a comprehensive assessment for easiness of dismantling and reusability of materials. Results of the calculations performed by the system have been analysed in order to characterize recycling properties of the cleaner.
A nanoparticle formation model considering layered motion based on an electrical explosion experiment with Al wires
Authors: ZHANG 张 Jiangbo 江波） , GAO 高 Hongxu 红旭 , XIAO 肖 Fei 飞） , LIU 刘 Wei 威 , LIANG 梁 Taixin 泰鑫 , MA 马 Zhongliang 中亮
Published: July 2022

To study the evolution of nanoparticles during Al wire electrical explosion, a nanoparticle formation model that considered layered motion was developed, and an experimental system was set up to carry out electrical explosion experiments using 0.1 mm and 0.2 mm Al wires. The characteristic parameters and evolution process during the formation of nanoparticles were calculated and analyzed. The results show that the maximum velocities of the innermost and outermost layers are about 1200 m·s−1 and 1600 m·s−1, and the velocity of the middle layer is about 1400 m·s−1, respectively. Most of the nanoparticles are formed in the temperature range of 2600 K‒2500 K. The characteristic temperature for the formation of Al nanoparticles is ∼2520 K, which is also the characteristic temperature of other parameters. The size distribution range of the formed nanoparticles is 18 to 110 nm, and most of them are around 22 nm. The variation of saturated vapor pressure determines the temperature distribution range of particle nucleation. There is a minimum critical diameter of particles (∼25 nm); particles smaller than the critical diameter can grow into larger particles during surface growth. Particle motion has an effect on the surface growth and aggregation process of particles, and also on the distribution area of larger-diameter particles. The simulation results are in good agreement with the experiments. We provide a method to estimate the size and distribution of nanoparticles, which is of great significance to understand the formation process of particles during the evolution of wire electrical explosion.
Gore, Madhav Sadashiv
Authors: Mane Purnima , Bharat Shalini
Published: July 2022

Madhav Sadashiv Gore (1921–2010) was an acclaimed social scientist and social work educator who fostered a strong link between social work and the social sciences. He was also a distinguished academic administrator who headed some of India’s most prominent educational institutions, including the Tata Institute of Social Sciences (TISS), which he led for two decades as director (1962–1982).
Maternal perfluorooctane sulfonic acid exposure during rat pregnancy causes hypersensitivity to angiotensin II and attenuation of endothelium-dependent vasodilation in the uterine arteries
Authors: Dangudubiyyam Sri Vidya , Mishra Jay S , Song Ruolin , Kumar Sathish
Published: July 2022

Epidemiological studies show a strong association between environmental exposure to perfluorooctane sulfonic acid (PFOS) and preeclampsia and fetal growth restriction; however, the underlying mechanisms are unclear. We tested the hypothesis that gestational PFOS exposure leads to pregnancy complications via alterations in uterine vascular endothelium-independent angiotensin II-related mechanisms and endothelium-derived factors such as nitric oxide. Pregnant Sprague-Dawley rats were exposed to PFOS 0.005, 0.05, 0.5, 5, 10, and 50 μg/mL through drinking water from gestational day 4 to 20, and dams with PFOS 50 μg/mL were used to assess mechanisms. PFOS exposure dose dependently increased maternal blood pressure but decreased fetal weights. Uterine artery blood flow was lower and resistance index was higher in the PFOS dams. In PFOS dams, uterine artery contractile responses to angiotensin II were significantly greater, whereas contractile responses to K+ depolarization and phenylephrine were unaffected. Plasma angiotensin II levels were not significantly different between control and PFOS dams; however, PFOS exposure significantly increased Angiotensin II type 1 receptor (AGTR1) and decreased AGTR2 protein levels in uterine arteries. Endothelium-dependent relaxation response to acetylcholine was significantly reduced with decreased endothelial nitric oxide synthase expression in the uterine arteries of PFOS dams. Left ventricular hypertrophy and fibrosis were observed, along with increased ejection fraction and fractional shortening in PFOS dams. These results suggest that elevated maternal PFOS levels decrease uterine blood flow and increase vascular resistance via heightened angiotensin II-mediated vasoconstriction and impaired endothelium-dependent vasodilation, which provides a molecular mechanism linking elevated maternal PFOS levels with gestational hypertension and fetal growth restriction.
Temporal variation in DNA methylation during gonadal development in a reptile with temperature-dependent sex determination
Authors: Liu Fang , Xu Haoyang , Ni Wei , Wang Yakun , Hong Xiaoyou , Li Wei , Yu Lingyun , Chen Chen , Wei Chengqing , Liu Xiaoli , Zhu Xinping
Published: July 2022

DNA methylation plays a significant role in transducing external environmental signals to a cellular response in reptiles; however, whether the methylation patterns are conserved across species remains unclear. Here, we examined the genome-wide DNA methylation differentiation between male and female hatchling gonads of the temperature-dependent sex determination (TSD) Mauremys mutica (M. mutica) using methylation-dependent restriction-site associated DNA sequencing (MethylRAD-seq) to test differentially methylated genes underlying sexual development. Several categories, including heat-shock genes (HSP90A, HSP30C), histone- (KDM8) and ubiquitin-related genes (TRIM39), kinases (WNK3), and gonad differentiation or gonadal-development-related genes (HSD17B8, HSD17B12), were identified as candidates for future study. Additionally, we identified several regulatory pathways potentially mediating TSD thermosensitivity such as the GnRH signaling pathway and calcium signaling pathway. These findings provide evidence that sexually dimorphic DNA methylation may be associated with sex determination or sex differentiation in TSD M. mutica.
A Direct Posterior Approach for Subtalar Distraction Arthrodesis
Authors: Lindsey Benjamin B. , Bettin Clayton C.
Published: July 2022

Because of soft tissue constraints, definitive management of hindfoot trauma occasionally requires a direct posterior approach via a coronal split of the Achilles tendon. This article and the accompanying video demonstrate a direct posterior approach for subtalar distraction arthrodesis and review treatment decisions involved with management of these complex cases.
Delayed Distraction Bone Block Arthrodesis for a Sanders IV Calcaneus Fracture Nonunion Using Tricortical Iliac Crest Allograft and Reamer/Irrigator/Aspirator Femoral Autograft
Authors: Solasz Sara Jo , Ganta Abhishek , Konda Sanjit R.
Published: July 2022

We present the surgical technique for arthrodesis of the subtalar and calcaneocuboid joints of a Sanders type IV calcaneal fracture nonunion via a distraction bone block arthrodesis technique with tricortical iliac crest allograft combined with reamer/irrigator/aspirator autograft from the patient's femur. A lateral extensile approach to the calcaneus was used for the exposure, which allowed the surgeon to follow the stepwise complex surgical plan outlined here. Calcaneal nonunions are difficult to treat, but good outcomes can be achieved if proper technique with bone grafting is used.