bluuebunny/crossref_metadata_2025 huggingface dataset:
Crevice Corrosion Behavior of Alloy 690 in High-Temperature Aerated Chloride Solution
Authors: Ning Fangqiang , Tan Jibo , Zhang Ziyu , Wang Xiang , Wu Xinqiang , Han En-Hou , Ke Wei
Published: August 2022

Crevice corrosion behavior of Alloy 690 in high-temperature aerated chloride solution was studied using a self-designed crevice device. The SEM, EDS, XRD, and XPS analyses results indicated that the oxide films outside the crevice consisted of Ni-Cr oxides containing a small amount of hydroxides, and the oxide films on crevice mouth consisted of a (Ni,Fe)(Fe,Cr)2O4 spinel oxides outer layer and a Cr(OH)3 inner layer, and the oxide films inside the crevice consisted of a α-CrOOH outer layer and a Cr(OH)3 inner layer. When crevice corrosion occurred, the hydrolysis of Cr3+ led to the formation of Cr(OH)3 inside the crevice, and caused the pH value of crevice solution to decrease, and Cl− migrated from outside the crevice into inside the crevice due to electrical neutrality principle and accumulation. When the water chemistry inside the crevice reached the critical value of active dissolution of metal, the active dissolution of metal inside the crevice occurred. In addition, (Ni,Fe)(Fe,Cr)2O4 spinel oxides on the crevice mouth were formed by the deposition of metal ions migrated from inside the crevice. The mechanism of crevice corrosion and the formation mechanism of oxide films at different regions were also discussed.
Key Technologies of Physical and Virtual Test Rig for Railway Freight Car body
Authors: Zhao Shangchao , Li Xiangwei , Wang Dongpo , Li Wenquan
Published: August 2022

On the one hand, considering that the traditional fatigue method of railway freight cars is based on damage as a parameter, the influence of stress waveform cannot be considered. On the other hand, physical experiments have the characteristics of lag, long period, and high cost. The full-scale physical test and virtual test of car body are carried out. First of all, the data processing method of small deletion and the inverse problem load acquisition method based on data to data are proposed. Secondly, the dynamic stress calculation method with the bench as the boundary is proposed. Finally, taking the obtained load as the input of the physical and virtual bench, a new fatigue test method for simulating the running attitude of the car body line is completed. The acceleration RMS error of the C70E gondola body is less than 6%, the stress RMS is less than 13%, and the equivalent mileage is 3.125 million highway test results show that the car meets the life requirements of the car body. The inverse problem analysis results of virtual and physical tests are basically consistent, and the study of this method provides a basis for improving the fatigue reliability of freight car bodies.
Effect of Yttrium on the Microstructure and Mechanical Properties of PH13-8Mo Stainless Steels Produced by Selective Laser Melting
Authors: Wang Chang-Jun , Liu Chang , Zhang Meng-Xing , Jiang Lu , Liu Yu , Liu Zhen-Bao , Liang Jian-Xiong
Published: August 2022

In the present work, PH13-8Mo stainless steel parts without yttrium and with yttrium (Y) were manufactured by selective laser melting (SLM). The microstructure, phase composition and grain orientation of the stainless steels parts with Y and without Y were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), electron-backscatter diffraction (EBSD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The characterization results revealed that the addition of Y clearly refined the grain size of the PH13-8Mo steel formed part, resulting in more equiaxed massive grains and in a less anisotropic microstructure. PH13-8Mo stainless steel formed parts were mainly composed of martensite and retained austenite. The addition of Y could significantly increase the content of retained austenite and also generate nano-sized precipitates containing Y. The mechanical test results showed that both strength and toughness of the shaped parts containing Y were improved synergistically. The yield strength reached 1443 MPa, the elongation was 12.2%, and the room temperature impact energy reached 124.25 J/cm2. The strengthening and toughening by Y of the formed parts were mainly attributed to grain refinement, higher volume fraction of the retained austenite and the formation of nano-sized precipitates containing Y.
A Clinical Risk Assessment of a 3D-Printed Patient-Specific Scaffold by Failure Modes and Effects Analysis
Authors: Qi Lim Ping , Huey Lim Sue , Sherilyn Maria , Fernandez-Medina Tulio , Ivanovski Sašo , Hosseinpour Sepanta
Published: August 2022

This study aims to carry out a risk assessment to identify and rectify potential clinical risks of a 3D-printed patient-specific scaffold for large-volume alveolar bone regeneration. A survey was used to assess clinicians’ perceptions regarding the use of scaffolds in the treatment of alveolar defects and conduct a clinical risk assessment of the developed scaffold using the Failure Modes and Effects Analysis (FMEA) framework. The response rate was 69.4% with a total of 41 responses received. Two particular failure modes were identified as a high priority through the clinical risk assessment conducted. The highest mean Risk Priority Number was obtained by “failure of healing due to patient risk factors” (45.7 ± 27.7), followed by “insufficient soft tissue area” (37.8 ± 24.1). Despite the rapid developments, finding a scaffold that is both biodegradable and tailored to the patient’s specific defect in cases of large-volume bone regeneration is still challenging for clinicians. Our results indicate a positive perception of clinicians towards this novel scaffold. The FMEA clinical risk assessment has revealed two failure modes that should be prioritized for risk mitigation (safe clinical translation). These findings are important for the safe transition to in-human trials and subsequent clinical use.
Effects of Preparation Methods on the Microstructure and Mechanical Properties of Graphene-Reinforced Alumina Matrix Composites
Authors: Zhang Danxia , Wu Xiaoqian , Jia Bi , Jiang Hanmei , Liu Yin , Wang Rong , Yang Qian , Wu Huiming , Wu Chunyan
Published: August 2022

Recent years have witnessed a growing research interest in graphene-reinforced alumina matrix composites (Al2O3-G). In this paper, to better achieve the dispersion of graphene in composites, a ball milling method for adding raw materials step by step, called stepwise feeding ball milling, was proposed. The Al2O3-1.0 wt % graphene composites were prepared by this stepwise feeding ball milling and hot pressing. Then, the effects of sintering temperature and sintering pressure on the microstructure and mechanical properties of composites were studied. Results showed that the bending strength, fracture toughness and Vickers hardness of composites increased firstly and then decreased with increasing sintering temperature. The mechanical properties of composites were all at their maximum with the sintering temperature of 1550 °C. For example, the bending strength of composites reached 754.20 MPa, which was much bigger than 478.03 MPa at 1500 °C and 364.01 MPa at 1600 °C. Analysis suggested that the strength of composites was mainly related to the grain size, microflaw size and porosity.
Aluminum Perlite Syntactic Foams
Authors: Thalmaier György , Sechel Niculina Argentina , Csapai Alexandra , Popa Catalin Ovidiu , Batin Gabriel , Gábora Andras , Mankovits Tamas , Vida-Simiti Ioan
Published: August 2022

This paper presents the usage of spark plasma sintering (SPS) as a method to obtain aluminum-expanded perlite syntactic foams with high porosity. In the test samples, fine aluminum powder with flaky shape particles was used as matrix material and natural, inorganic, granular, expanded perlite was used as a space holder to ensure high porosity (35–57%) and uniform structure. SPS was used to consolidate the specimens. The structures were characterized by scanning electron microscopy and compression tests. Energy absorption (W~7.49 MJ/m3) and energy absorption efficiency (EW < 90%) were also determined.
Aluminide Diffusion Coatings on IN 718 by Pack Cementation
Authors: Cojocaru Mihai Ovidiu , Branzei Mihai , Druga Leontin Nicolae
Published: August 2022

This paper addressed the issues of both direct and indirect synthesis of Ni aluminides by pack cementation (pure Ni and IN 718 superalloy). On the Al-Ni diffusion twosome under pressure, at temperatures below and above the Al melting temperature, the appearance and evolution of diffusion porosity because of the Kirkendall–Frenkel effect manifestation was highlighted. It has been confirmed that, as the temperature rises above the Al melting temperature, the porosity decreases. Nickel-based superalloys, and in particular IN 718, significantly increase their performance by increasing the aluminides proportion in the top diffusion coating. This is made possible by changing the value of the Al and Ni weight percentage ratio in this area (noted as Al/Ni). In the case of the diffusion twosome between IN 718 and pack aluminizing mixtures, having in their composition as active components Al powder, Ferroaluminum (FeAl40) or mixtures of Al and Fe powders, at processing temperatures above the Al melting temperature, by modifying the active component of the mixture, substantial changes in the Al/Ni values were observed, as well as in the maximum %Al in the diffusion coating and of its thickness. It was found that, when switching from Al to FeAl40 or powder mixture (Al + Fe), the Al/Ni value changes between 3.43 and 1.01, from initial subunit values. The experiments confirmed that the highest %Al in the top aluminized diffusion coating, for IN 718, was obtained if the powder mixture contained 66.34 wt.% Al.
Microwave Absorption Properties of Carbon Black-Carbonyl Iron/Polylactic Acid Composite Filament for Fused Deposition Modeling
Authors: Wang Fei , Zhou Qianfeng , Zhang Zhe , Gu Yonghua , Zhang Jiliang , Jiang Kaiyong
Published: August 2022

A single microwave absorbent and simple coating structure cannot meet the increasing requirements for broadband and strong absorption. Three-dimensional printing is an effective way to prepare multi-component complex structure metamaterial absorbers, and the key is to prepare raw materials with excellent absorption properties, suitable for 3D printing. In this paper, CB-CIP/PLA composite filament was prepared via a high-energy mixer and twin-screw extruder by compounding the dielectric loss material carbon black (CB) and the magnetic loss material carbonyl iron powder (CIP) with polylactic acid (PLA) as the matrix. The coaxial ring test piece was printed by FDM technology, and the microstructure of the composites was observed and analyzed by SEM. Meanwhile, the electromagnetic parameters of the composites were examined by a vector network analyzer, mainly studying the influence of the CB and CIP content and thickness on the microwave absorbing properties of the composite material. The results show that when the CB content is 20% and the CIP content is 30%, the CB-CIP/PLA composite has excellent microwave absorption and broad bandwidth. When the matching thickness is 1.6 mm, the minimum reflection loss (RL) reaches −51.10 dB; when the thickness is 1.7 mm, the effective absorption bandwidth (RL < −10 dB) is 5.04 GHz (12.96–18 GHz), nearly covering the whole Ku band. This work provides an efficient formulation and process to prepare an absorbing composite filament for FDM.
Experimental Investigation on Mechanical Properties of Geocell Strips at Low Temperature
Authors: Bai Qiyu , He Guofeng , Wang Yong , Liu Jie
Published: August 2022

Geocell is widely used in the treatment of poor roadbed, which can restrain soil laterally and improve the stability of soil. In cold area engineering, a change in temperature can influence the mechanical properties of geocell of different materials. To study the mechanical response of geocell at low temperatures, three types of geocell strips commonly used in engineering, namely the polyethylene (HDPE), polypropylene (PP), and polyester (PET), were studied via the uniaxial tensile test at the ambient temperatures of −5 °C, −20 °C, and −35 °C, respectively. Meanwhile, the tensile strength, fracture mode, and temperature sensitivity of geocell specimens were compared. It is concluded that: (1) at low temperatures, the tensile strengths of HDPE and PET geocell strips are significantly improved, while that of the PP geocell strip is less sensitive to the temperature. (2) The PP geocell is subject to a brittle failure at all ambient temperatures. The PET geocell strip experiences a hard-ductile failure at normal temperatures of −5 °C and −20 °C. While in the tensile test at −35 °C, it is prone to brittle failure and hard-ductile failure. The HDPE geocell strip suffers from ductile failure at all ambient temperatures. (3) At low temperatures, overall, the tensile properties of the PET geocell strip is better than those of the PP and HDPE geocell strips.
A Comprehensive Study on the Rejuvenation Efficiency of Compound Rejuvenators for the Characterization of the Bituminous Binder, Mortar, and Mixture
Authors: Li Mingliang , Ren Shisong , Liu Xueyan , Wu Zhe , Zhang Haopeng , Fan Weiyu , Lin Peng , Xu Jian
Published: August 2022

This study aims to comprehensively investigate the rejuvenation efficiency of various self-developed compound rejuvenators on the physical, mechanical, and aging properties of aged bitumen, asphalt mortar, and mixture. The results revealed that the restoration capacity of vacuum distilled-oil rejuvenators on high-and-low temperature performance-grade of aged bitumen is more significant. In contrast, an aromatic-oil based rejuvenator is good at enhancing low-temperature grade and aging resistance. Moreover, the temperature and time of the curing conditions for mixing recycling of asphalt mixture were optimized as 150 °C and 120 min. Furthermore, the sufficient anti-rutting, structural stability, and moisture resistance of recycled asphalt mixture affirmed the rejuvenation efficiency of compound rejuvenators.
Research on the Manufacturing Process and Heat Transfer Performance of Ultra-Thin Heat Pipes: A Review
Authors: Duan Liuyang , Li Hang , Du Jinguang , Liu Kun , He Wenbin
Published: August 2022

This paper reviews the manufacturing process of ultra-thin heat pipes and the latest process technologies in detail, focusing on the progress of the shape, structure, and heat transfer mechanism of the wick. The effects of the filling rate and tilt angle on the heat transfer performance of the ultra-thin heat pipe, as well as the material selection of ultra-thin heat pipes, is sorted out, and the surface modification technology is analyzed. Besides, the optimal design based on heat pipes is discussed. Spiral woven mesh wick and multi-size composite wick have significant advantages in the field of ultra-thin heat pipe heat transfer, and comprehensive surface modification technology has huge potential. Finally, an outlook on future scientific research in the field of ultra-thin heat pipes is proposed.
Inversion Method of the Young’s Modulus Field and Poisson’s Ratio Field for Rock and Its Test Application
Authors: Yin Yanchun , Liu Guangyan , Zhao Tongbin , Ma Qinwei , Wang Lu , Zhang Yubao
Published: August 2022

As one typical heterogeneous material, the heterogeneity of rock micro parameters has an important effect on its macro mechanical behavior. The study of the heterogeneity of micro parameters is more important to reveal the root cause of deformation and failure. However, as a typical heterogeneous material, the current testing and inversion method is not suitable for micro parameters measurement for the rock. Aiming at obtaining the distribution of micro Young’s modulus and micro Poisson’s ratio of the rock, based on the digital image correlation method (DIC) and finite element method (FEM), this paper proposed a parameter field inversion method, namely the DF-PF inversion method. Its inversion accuracy is verified using numerical simulation and laboratory uniaxial compression test. Considering the influences of heterogeneity, stress state and dimension difference, the average inversion error of Young’s modulus field and Poisson’s ratio field are below 10%, and the proportion of elements with an error of less than 15% accounts for more than 86% in the whole specimen model. Compared with the conventional measuring method, the error of macro Young’s modulus and macro Poisson’s ratio calculated by the DF-PF inversion method is less than 2.8% and 9.07%, respectively. Based on the statistical analysis of Young’s modulus field and Poisson’s ratio field, the parameter homogeneity and quantitative function relation between the micro parameter and the principal strain can also be obtained in laboratory tests. The DF-PF inversion method provides a new effective method of testing Young’s modulus field and Poisson’s ratio field of the rocks under complex stress states.
Effect of P2O5 and Na2O on the Solubility of Molybdenum and Structural Features in Borosilicate Glass
Authors: Liu Hao , Zhu Yongchang , Huo Jichuan , Cui Zhu , Zhang Xingquan , Jiang Qin , Yang Debo , Meng Baojian
Published: August 2022

In this paper, the effect of doping phosphorus in a borosilicate glass matrix to improve the solubility of Mo was investigated by X-ray diffraction (XRD), Raman, and solid-state nuclear magnetic resonance (NMR) spectroscopy, and the effectiveness of Na content on P species inhibiting the growth of the crystallization of Mo was assessed. The results indicate that phosphate-doped borosilicate glass can host 4 mol% of Mo, and that such a borosilicate glass matrix could only accommodate 1 mol% of Mo without phosphate doping. The effectiveness of phosphorus may be correlated with the Na content in borosilicate glass, and a high Na content borosilicate glass matrix requires more P doping to accommodate Mo. In addition, incorporating large amounts of P can compromise the aqueous durability of the glass matrix.
Analysis of Cutting Stability of a Composite Variable-Section Boring Bar with a Large Length-to-Diameter Ratio Considering Internal Damping
Authors: Ma Jingmin , Xu Jianfeng , Li Longfei , Liu Xingguang , Gao Ming
Published: August 2022

Chattering in composite deep-hole boring can directly affect surface processing quality and efficiency and has always been a research hotspot in machining mechanics. In this study, based on Euler–Bernoulli beam theory, the fine control equations for the cutting stability of composite variable-section boring bars were established using the Hamilton principle, in which the sectional change and internal damping of the material were considered. Next, using the Galerkin method and semi-discrete method, the effects of the taper ratio, damping ratio, length-to-diameter ratio, and ply angle on the free vibration characteristics and cutting stability were analyzed in detail. The results show that at a low damping ratio, both the first-order inherent frequency and boring stability can be enhanced with the increase in the taper ratio; at a large damping ratio, increasing the taper ratio can reduce the first-order inherent frequency and boring stability. Finally, the effects of the sectional change on the inherent frequency, displacement response, and convergence were analyzed. A numerical simulation was performed for the model reliability validation. The present research results can provide a theoretical basis and technical guidance for analyzing the cutting stability and fine control of composite variable-section boring bars with large length-to-diameter ratios.
Research Progress and Challenges in Laser-Controlled Cleaning of Aluminum Alloy Surfaces
Authors: Deng Jian , Zhao Guanrong , Lei Jieheng , Zhong Lin , Lei Zeyong
Published: August 2022

Aluminum alloys have been widely utilized in automobiles, aircraft, building structures, and high-speed railways industries due to their excellent structural and mechanical properties. Surface oxide film removal prior to aluminum alloy welding and old paint removal prior to repainting aluminum alloy surfaces are critical factors in ensuring the welding quality and service life of aluminum alloy products. Because of its unique advantages, such as environmental protection and precision control, laser-controlled cleaning has great application potential as a surface cleaning technology in removing oxide films and paint layers on aluminum alloy surfaces. In this paper, the mechanism of laser cleaning of oxide films and paint layers on aluminum alloy is discussed. Furthermore, the impact of various processing parameters such as laser beam power, energy density, scanning speed, and so on is analyzed in detail. After laser cleaning, the corrosion resistance, welding performance, adhesive performance, and other properties of the aluminum alloy are optimized. This paper also discusses several real-time detection technologies for laser cleaning. A summary and the development trend are provided at the end of the paper.
The Role of Physicians’ Digital Tools in Pharmacological Management of Type 2 Diabetes Mellitus
Authors: Janež Andrej , Ješe Rok , Haluzík Martin , Rizzo Manfredi
Published: August 2022

Background and Objectives: The constantly increasing prevalence of type 2 diabetes mellitus (T2DM) and the advent of new treatment options have made management of T2DM patients more demanding. We aimed to (a) estimate the familiarity of general practitioners with novel T2DM treatment options, (b) determine whether a digital tool can aid in their treatment decisions and (c) demonstrate that an evidence-based digital clinical support tool can be made using an existing digital platform. Materials and methods: This proof-of-concept study consisted of two parts: We first conducted a simple online survey among general practitioners of three European countries to estimate their familiarity with novel T2DM treatment options and to determine whether they believe that a digital tool can aid in their T2DM treatment decisions. We then proceeded to develop a new digital tool that provides quick, evidence-based support for treatment of patients with T2DM using an existing digital platform. Results: The online survey was completed by 129/5278 physicians (94 from Italy, 22 from Czech Republic and 13 from Slovenia). Only 30.7% of all general practitioners reported to be either very or extremely familiar with novel T2DM treatments; the vast majority of participating general practitioners (82.8%) reported that they would find a digital clinical decision support tool for treating T2DM patients either very or extremely useful. A digital tool which features the characteristics deemed most important by the polled physicians was subsequently developed. Conclusions: The results of the online survey showed that familiarity of general practitioners with novel T2DM treatment options is relatively low and that there is a need for digital clinical decision support tools intended to facilitate treatment decisions in T2DM patients. We demonstrated that such a tool can easily be developed using an existing digital platform.
Emergency Surgery for Colon Diseases in Elderly Patients—Analysis of Complications, and Postoperative Course
Authors: Pacilli Mario , Fersini Alberto , Pavone Giovanna , Cianci Pasquale , Ambrosi Antonio , Tartaglia Nicola
Published: August 2022

Background and Objectives: Colon diseases can turn in a clinical emergency with the onset of some important complications. Some critical conditions are more common in aged patients because they are frailer. The aim of this study is to examine patients over 80 years of age who are undergoing emergency colorectal surgery, and evaluating the aspects associated with post-operative complications and other problems in the short term. Methods: From November 2020 to February 2022, we included 32 consecutive patients older than 80 undergoing emergency surgery due to colon diseases. We collected and analysed all demographic and operative data, and then applied CR-POSSUM score and correlated this with postoperative hospital stay and the onset of postoperative complications according to the Clavien Dindo classification. Results: Postoperative factors were selectively evaluated based on the clinical scenario and different colic pathologies. There were no statistically significant differences, in terms of postoperative hospital stay, postoperative complications, reoperation rate and 30-day mortality. The number of cases of blood transfusions was significant and was more numerous in cases of intestinal perforation and bleeding cases. The value of the Operative Severity Score in bowel perforations was significantly higher. Conclusions: The use of a score to stratify the risk is a useful tool, especially in elderly patients undergoing emergency surgery. The CR-POSSUM score was important for predicting morbidity in our study. Emergency manifestations of colon diseases in the elderly show higher morbidity and mortality rates. The effect of age on outcome is a concept that needs to be emphasized, so further investigation is needed.
Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio as Prognostic Markers for Advanced Non-Small-Cell Lung Cancer Treated with Immunotherapy: A Systematic Review and Meta-Analysis
Authors: Platini Hesti , Ferdinand Eric , Kohar Kelvin , Prayogo Stephanie , Amirah Shakira , Komariah Maria , Maulana Sidik
Published: August 2022

Background and Objectives: Advanced non-small-cell lung cancer (NSCLC) has led to a high number of mortalities. Immunotherapy, as a first-line treatment in advanced NSCLC, currently has no clarity regarding its prognostic markers to assess the treatment outcome. This systematic review aimed to evaluate neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as prognostic markers in advanced NSCLC patients treated with immunotherapy. Materials and Methods: This systematic review was conducted using the PRISMA guidelines, starting from screening for relevant studies from several databases. Each included cohort study was further assessed by using the Newcastle–Ottawa Quality Assessment Scale, and the available data were extracted for qualitative and quantitative synthesis in pooled and subgroup analysis. Results: A total of 1719 patients were included in this meta-analysis. Hazard ratio (HR) outcomes for progression-free survival (PFS) and overall survival (OS) for NLR and PLR showed significant results, supporting NLR and PLR as prognostic markers (NLR: HR PFS 2.21 [95% CI: 1.50–3.24; p < 0.0001] and HR OS 2.68 [95% CI: 2.24–3.6; p < 0.0001]; PLR: HR PFS 1.57 [95% CI: 1.33–1.84; p < 0.00001] and HR OS 2.14 [95% CI: 1.72–2.67; p < 0.00001]). Subgroup analysis with a cut-off value of 5 for NLR and 200 for PLR also demonstrated notable outcomes. Higher NLR and PLR levels are associated with poor prognostic. Conclusions: There is considerable evidence regarding both markers as prognostic markers in NSCLC patients treated with immunotherapy. However, further studies with more homogeneous baseline characteristics are required to confirm these findings.
Employers’ Perceived Career Impact of Canada’s Parental-Leave Extension from 35 to 61 Weeks—“An Empty Gift”
Authors: Pettigrew Rachael N.
Published: August 2022

Introduced in 1990, Canadian parental-leave policy has seen several iterations. The most recent policy change, introduced in December 2017, extended parental leave from 35 to 61 weeks, resulting in longer work interruptions. Forty-six structured interviews were conducted to explore Canadian employers’ perception of how use of the new extended leave may impact employees’ careers. Though some employers offered explicit support for employees, a large proportion of employers felt that use of the longer leave would negatively impact employees’ careers. The presence of unions appeared to insulate employees from a career impact. A thematic analysis revealed that the career impact perceived by employers resulted from concern for employees’ missed opportunities (e.g., training, promotions), length of absence, specific employment situations (e.g., role, level in the organization, career ambitions, and tenure with the organization), and gendered views of employee leave use. Given that the vast majority of Canadian parental-leave users continue to be women, this research highlights the presence of considerable workplace stigma for work interruptions and that longer parental leave may only serve to exacerbate that stigma, especially for women. Recommendations and implications for parental-leave policy, workers, and employers are discussed.
Ultrafast Heating Heat Treatment Effect on the Microstructure and Properties of Steels
Authors: Gaggiotti Matteo , Albini Luciano , Di Nunzio Paolo , Di Schino Andrea , Stornelli Giulia , Tiracorrendo Giulia
Published: August 2022

The adoption of the ultrafast heating (UFH) process has gained much attention in the last few years, as the green energy and minimization of CO2 emissions are the main aspects of contemporary metal science and thermal treatment. The effect of ultrafast heating (UFH) treatment on carbon steels, non-oriented grain (NGO) electrical steels, and ferriticor austenitic stainless steels is reported in this review. The study highlights the effect of ultrarapid annealing on microstructure and textural evolution in relation to microstructural constituents, recrystallization temperatures, and its effect on mechanical properties. A strong influence of the UFH process was reported on grain size, promoting a refinement in terms of both prior austenite and ferrite grain size. Such an effect is more evident in medium–low carbon and NGO steels than that in ferritic/austenitic stainless steels. A comparison between conventional and ultrafast annealing on stainless steels shows a slight effect on the microstructure. On the other hand, an evident increase in uniform elongation was reported due to UFH. Textural evolution analysis shows the effect of UFH on the occurrence of the Goss component (which promotes magnetic properties), and the opposite with the recrystallization g-fiber. The recovery step during annealing plays an important role in determining textural features; the areas of higher energy content are the most suitable for the nucleation of the Goss component. As expected, the slow annealing process promoted equiaxed grains, whereas rapid heating promoted microstructures with elongated grains as a result of the cold deformation.
Investigation of the Microstructure and Properties of Aluminum–Copper Compounds Fabricated by the High-Pressure Die Casting Process
Authors: Nolte Nane , Lukasczyk Thomas , Mayer Bernd
Published: August 2022

The material combination of aluminum and copper is increasingly coming into focus, especially for electrical contact applications. Investigations of different casting processes show that a significant influence for the formation of a material bond is the thermal impact. For high-pressure die casting (HPDC) processes, the impact is quite low, e.g., due to short cycle times. Despite the high efficiency of this technology, currently there are hardly any investigations in this respect. So, the technology was used in this study to produce aluminum–copper compounds and analyze interfacial layers by means of SEM images and EDX measurements. Furthermore, the mechanical and electrical properties of the compounds were determined by means of tensile shear tests and measurements of the electrical conductivity. By modifying specimen geometry, the thermal impact could be increased and, thus, enhanced compound properties were achieved. Overall, compounds of sufficiently high mechanical strength, as well as electrical conductivity, could be produced by HPDC processes, demonstrating the high technical and economic potential of this casting technique.
Understanding the Mechanism of Abrasive-Based Finishing Processes Using Mathematical Modeling and Numerical Simulation
Authors: Hashmi Abdul Wahab , Mali Harlal Singh , Meena Anoj , Saxena Kuldeep K. , Puerta Ana Pilar Valerga , Prakash Chander , Buddhi Dharam , Davim J. P. , Abdul-Zahra Dalael Saad
Published: August 2022

Recent advances in technology and refinement of available computational resources paved the way for the extensive use of computers to model and simulate complex real-world problems difficult to solve analytically. The appeal of simulations lies in the ability to predict the significance of a change to the system under study. The simulated results can be of great benefit in predicting various behaviors, such as the wind pattern in a particular region, the ability of a material to withstand a dynamic load, or even the behavior of a workpiece under a particular type of machining. This paper deals with the mathematical modeling and simulation techniques used in abrasive-based machining processes such as abrasive flow machining (AFM), magnetic-based finishing processes, i.e., magnetic abrasive finishing (MAF) process, magnetorheological finishing (MRF) process, and ball-end type magnetorheological finishing process (BEMRF). The paper also aims to highlight the advances and obstacles associated with these techniques and their applications in flow machining. This study contributes the better understanding by examining the available modeling and simulation techniques such as Molecular Dynamic Simulation (MDS), Computational Fluid Dynamics (CFD), Finite Element Method (FEM), Discrete Element Method (DEM), Multivariable Regression Analysis (MVRA), Artificial Neural Network (ANN), Response Surface Analysis (RSA), Stochastic Modeling and Simulation by Data Dependent System (DDS). Among these methods, CFD and FEM can be performed with the available commercial software, while DEM and MDS performed using the computer programming-based platform, i.e., “LAMMPS Molecular Dynamics Simulator,” or C, C++, or Python programming, and these methods seem more promising techniques for modeling and simulation of loose abrasive-based machining processes. The other four methods (MVRA, ANN, RSA, and DDS) are experimental and based on statistical approaches that can be used for mathematical modeling of loose abrasive-based machining processes. Additionally, it suggests areas for further investigation and offers a priceless bibliography of earlier studies on the modeling and simulation techniques for abrasive-based machining processes. Researchers studying mathematical modeling of various micro- and nanofinishing techniques for different applications may find this review article to be of great help.
Thermoelectric Energy Micro Harvesters with Temperature Sensors Manufactured Utilizing the CMOS-MEMS Technique
Authors: Shen Yi-Xuan , Tsai Yao-Chuan , Lee Chi-Yuan , Wu Chyan-Chyi , Dai Ching-Liang
Published: August 2022

This study develops a TEMH (thermoelectric energy micro harvester) chip utilizing a commercial 0.18 μm CMOS (complementary metal oxide semiconductor) process. The chip contains a TEMH and temperature sensors. The TEMH is established using a series of 54 thermocouples. The use of the temperature sensors monitors the temperature of the thermocouples. One temperature sensor is set near the cold part of the thermocouples, and the other is set near the hot part of the thermocouples. The performance of the TEMH relies on the TD (temperature difference) at the CHP (cold and hot parts) of the thermocouples. The more the TD at the CHP of the thermocouples increases, the higher the output voltage and output power of the TEMH become. To obtain a higher TD, the cold part of the thermocouples is designed as a suspended structure and is combined with cooling sheets to increase heat dissipation. The cooling sheet is constructed of a stack of aluminum layers and is mounted above the cold part of the thermocouple. A finite element method software, ANSYS, is utilized to compute the temperature distribution of the TEMH. The TEMH requires a post-process to obtain the suspended thermocouple structure. The post-process utilizes an RIE (reactive ion etch) to etch the two sacrificial materials, which are silicon dioxide and silicon substrate. The results reveal that the structure of the thermocouples is completely suspended and does not show any injury. The measured results reveal that the output voltage of the TEMH is 32.5 mV when the TD between the CHP of the thermocouples is 4 K. The TEMH has a voltage factor of 8.93 mV/mm2K. When the TD between the CHP of the thermocouples is 4 K, the maximum output power of the TEMH is 4.67 nW. The TEMH has a power factor of 0.31 nW/mm2K2.
Development of Iron Nanoparticles (FeNPs) Using Biomass of Enterobacter: Its Characterization, Antimicrobial, Anti-Alzheimer’s, and Enzyme Inhibition Potential
Authors: Zafar Sania , Faisal Shah , Jan Hasnain , Ullah Riaz , Rizwan Muhammad , Abdullah  , Alotaibi Amal , Bibi Nadia , Rashid Amin Ur , Khattak Aishma
Published: August 2022

Nanotechnology is a new field that has gained considerable importance due to its potential uses in the field of biosciences, medicine, engineering, etc. In the present study, bio-inspired metallic iron nanoparticles (FeNPs) were prepared using biomass of Enterobacter train G52. The prepared particles were characterized by UV-spectroscopy, TGA, XRD, SEM, EDX, and FTIR techniques. The crystalline nature of the prepared FeNPs was confirmed by XRD. The SEM techniques revealed the particles size to be 23 nm, whereas in FTIR spectra the peaks in the functional group region indicated the involvement of bioactive compounds of selected bacterial strains in the capping of FeNPs. The EDX confirmed the presence of iron in the engineered FeNPs. The FeNPs were then evaluated for its antibacterial, antifungal, antioxidant, anti-inflammatory, anti-Alzheimer’s, anti-larvicidal, protein kinase inhibition, anti-diabetic, and biocompatibility potentials using standard protocols. Substantial activities were observed in almost all biological assays used. The antioxidant, anti-cholinesterase, and anti-diabetic potential of the prepared nanoparticles were high in comparison to other areas of biological potential, indicating that the FeNPs are capable of targeting meditators of oxidative stress leading to diabetes and Alzheimer’s disease. However, the claim made needs some further experimentation to confirm the observed potential in in vivo animal models.
Cross-Domain Active Learning for Electronic Nose Drift Compensation
Authors: Sun Fangyu , Sun Ruihong , Yan Jia
Published: August 2022

The problem of drift in the electronic nose (E-nose) is an important factor in the distortion of data. The existing active learning methods do not take into account the misalignment of the data feature distribution between different domains due to drift when selecting samples. For this, we proposed a cross-domain active learning (CDAL) method based on the Hellinger distance (HD) and maximum mean difference (MMD). In this framework, we weighted the HD with the MMD as a criterion for sample selection, which can reflect as much drift information as possible with as few labeled samples as possible. Overall, the CDAL framework has the following advantages: (1) CDAL combines active learning and domain adaptation to better assess the interdomain distribution differences and the amount of information contained in the selected samples. (2) The introduction of a Gaussian kernel function mapping aligns the data distribution between domains as closely as possible. (3) The combination of active learning and domain adaptation can significantly suppress the effects of time drift caused by sensor ageing, thus improving the detection accuracy of the electronic nose system for data collected at different times. The results showed that the proposed CDAL method has a better drift compensation effect compared with several recent methodological frameworks.
Stable and Fast Planar Jumping Control Design for a Compliant One-Legged Robot
Authors: Luo Guifu , Du Ruilong , Song Sumian , Yuan Haihui , Huang Zhiyong , Zhou Hua , Gu Jason
Published: August 2022

Compliant bipedal robots demonstrate a potential for impact resistance and high energy efficiency through the introduction of compliant elements. However, it also adds to the difficulty of stable control of the robot. To motivate the control strategies of compliant bipedal robots, this work presents an improved control strategy for the stable and fast planar jumping of a compliant one-legged robot designed by the authors, which utilizes the concept of the virtual pendulum. The robot was modeled as an extended spring-loaded inverted pendulum (SLIP) model with non-negligible torso inertia, leg inertia, and leg damping. To enable the robot to jump forward stably, a foot placement method was adopted, where due to the asymmetric feature of the extended SLIP model, a variable time coefficient and an integral term with respect to the forward speed tracking error were introduced to the method to accurately track a given forward speed. An energy-based leg rest length regulation method was used to compensate for the energy dissipation due to leg damping, where an integral term, regarding jumping height tracking error, was introduced to accurately track a given jumping height. Numerical simulations were conducted to validate the effectiveness of the proposed control strategy. Results show that stable and fast jumping of compliant one-legged robots could be achieved, and the desired forward speed and jumping height could also be accurately tracked. In addition to that, using the proposed control strategy, the robust jumping performance of the robot could be observed in the presence of disturbances from state variables or uneven terrain.
Variable Density Filling Algorithm Based on Delaunay Triangulation
Authors: Qiao Yujing , Lv Ning , Ouyang Xuefeng
Published: August 2022

The quality of the filling algorithm in additive manufacturing directly affects the strength of the part. The commonly used 3D printing filling algorithm at this stage is the classic filling algorithm. The density of each part in the filling region is the same, and there is a cavity structure in the transverse direction, which makes the strength of the part in the transverse direction lower. Therefore, this paper proposed a new filling algorithm—variable density filling algorithm based on Delaunay triangulation. First, we performed concave-polygon-convex decomposition on the filling area to form printing sub-regions; then, the filling density value was set according to the required intensity of each region, and we used the Poisson disk sampling algorithm to generate the filling point set. Finally, Delaunay triangulation was performed on the generated point set to generate filled traces. The comparison with the two commonly used classical filling algorithms proves that the algorithm can improve the strength of the part to a certain extent, and the printing time and the consumption of consumables will not increase significantly.
Clamping Fatigue Properties of Shrink-Fit Holder
Authors: Lai Zhouyi , Zhao Zhenyu , Guo Ting , Luo Yuyin , Zhou Houming , Li Changan
Published: August 2022

In order to explore the clamping fatigue properties of shrink-fit holders, ANSYS software was used in this study to analyze the thermal and contact stresses during the clamping process of the shrink-fit holder, and the fatigue analysis was performed by selecting the dangerous areas based on the two stresses. A numerical control shrink-fit holder clamping fatigue test device was manufactured, and the automatic clamping of the shrink-fit holder was executed in this study. After 500 clamping repetitions, a milling test was carried out on the shrink-fit bracket. By collecting the vibration signal of the workpiece during processing and measuring the change in the surface roughness of the workpiece, and then analyzing the change in the machining performance of the shrink-fit holder under different clamping times, we were able to compare and verify the accuracy of the finite element fatigue analysis.
Auto-Regression Model-Based Off-Line PID Controller Tuning: An Adaptive Strategy for DC Motor Control
Authors: Niembro-Ceceña José , Gómez-Loenzo Roberto , Rodríguez-Reséndiz Juvenal , Rodríguez-Abreo Omar , Odry Ákos
Published: August 2022

Brushed (B) and Brushless (BL) DC motors constitute the cornerstone of mechatronic systems regardless their sizes (including miniaturized), in which both position and speed control tasks require the application of sophisticated algorithms. This manuscript addresses the initial step using time series analysis to forecast Back EMF values, thereby enabling the elaboration of real-time adaptive fine-tuning strategies for PID controllers in such a control system design problem. An Auto-Regressive Moving Average (ARMA) model is developed to estimate the DC motor parameter, which evolves in time due to the system’s imperfection (i.e., unpredictable duty cycle) and influences the closed-loop performance. The methodology is executed offline; thus, it highlights the applicability of collected BDC motor measurements in time series analysis. The proposed method updates the PID controller gains based on the Simulink ™ controller tuning toolbox. The contribution of this approach is shown in a comparative study that indicates an opportunity to use time series analysis to forecast DC motor parameters, to re-tune PID controller gains, and to obtain similar performance under the same perturbation conditions. The research demonstrates the practical applicability of the proposed method for fine-tuning/re-tuning controllers in real-time. The results show the inclusion of the time series analysis to recalculate controller gains as an alternative for adaptive control.
Chitosan Nanoparticle Encapsulation of Antibacterial Essential Oils
Authors: Negi Arvind , Kesari Kavindra Kumar
Published: August 2022

Chitosan is the most suitable encapsulation polymer because of its natural abundance, biodegradability, and surface functional groups in the form of free NH2 groups. The presence of NH2 groups allows for the facile grafting of functionalized molecules onto the chitosan surface, resulting in multifunctional materialistic applications. Quaternization of chitosan’s free amino is one of the typical chemical modifications commonly achieved under acidic conditions. This quaternization improves its ionic character, making it ready for ionic–ionic surface modification. Although the cationic nature of chitosan alone exhibits antibacterial activity because of its interaction with negatively-charged bacterial membranes, the nanoscale size of chitosan further amplifies its antibiofilm activity. Additionally, the researcher used chitosan nanoparticles as polymeric materials to encapsulate antibiofilm agents (such as antibiotics and natural phytochemicals), serving as an excellent strategy to combat biofilm-based secondary infections. This paper provided a summary of available carbohydrate-based biopolymers as antibiofilm materials. Furthermore, the paper focuses on chitosan nanoparticle-based encapsulation of basil essential oil (Ocimum basilicum), mandarin essential oil (Citrus reticulata), Carum copticum essential oil (“Ajwain”), dill plant seed essential oil (Anethum graveolens), peppermint oil (Mentha piperita), green tea oil (Camellia sinensis), cardamom essential oil, clove essential oil (Eugenia caryophyllata), cumin seed essential oil (Cuminum cyminum), lemongrass essential oil (Cymbopogon commutatus), summer savory essential oil (Satureja hortensis), thyme essential oil, cinnamomum essential oil (Cinnamomum zeylanicum), and nettle essential oil (Urtica dioica). Additionally, chitosan nanoparticles are used for the encapsulation of the major essential components carvacrol and cinnamaldehyde, the encapsulation of an oil-in-water nanoemulsion of eucalyptus oil (Eucalyptus globulus), the encapsulation of a mandarin essential oil nanoemulsion, and the electrospinning nanofiber of collagen hydrolysate–chitosan with lemon balm (Melissa officinalis) and dill (Anethum graveolens) essential oil.