bluuebunny/crossref_metadata_2025 huggingface dataset:
Emergence of SARS-CoV-2 Variants in the World: How Could This Happen?
Authors: Parra-Lucares Alfredo , Segura Paula , Rojas Verónica , Pumarino Catalina , Saint-Pierre Gustavo , Toro Luis
Published: January 2022

The COVID-19 pandemic has had a significant global impact, with more than 280,000,000 people infected and 5,400,000 deaths. The use of personal protective equipment and the anti-SARS-CoV-2 vaccination campaigns have reduced infection and death rates worldwide. However, a recent increase in infection rates has been observed associated with the appearance of SARS-CoV-2 variants, including the more recently described lineage B.1.617.2 (Delta variant) and lineage B.1.1.529/BA.1 (Omicron variant). These new variants put the effectiveness of international vaccination at risk, with the appearance of new outbreaks of COVID-19 throughout the world. This emergence of new variants has been due to multiple predisposing factors, including molecular characteristics of the virus, geographic and environmental conditions, and the impact of social determinants of health that favor the genetic diversification of SARS-CoV-2. We present a literature review on the most recent information available on the emergence of new variants of SARS-CoV-2 in the world. We analyzed the biological, geographical, and sociocultural factors that favor the development of these variants. Finally, we evaluate the surveillance strategies for the early detection of new variants and prevent their distribution outside these regions.
Promising Assays for Examining a Putative Role of Ribosomal Heterogeneity in COVID-19 Susceptibility and Severity
Authors: Shiao Yih-Horng
Published: January 2022

The heterogeneity of ribosomes, characterized by structural variations, arises from differences in types, numbers, and/or post-translational modifications of participating ribosomal proteins (RPs), ribosomal RNAs (rRNAs) sequence variants plus post-transcriptional modifications, and additional molecules essential for forming a translational machinery. The ribosomal heterogeneity within an individual organism or a single cell leads to preferential translations of selected messenger RNA (mRNA) transcripts over others, especially in response to environmental cues. The role of ribosomal heterogeneity in SARS-CoV-2 coronavirus infection, propagation, related symptoms, or vaccine responses is not known, and a technique to examine these has not yet been developed. Tools to detect ribosomal heterogeneity or to profile translating mRNAs independently cannot identify unique or specialized ribosome(s) along with corresponding mRNA substrate(s). Concurrent characterizations of RPs and/or rRNAs with mRNA substrate from a single ribosome would be critical to decipher the putative role of ribosomal heterogeneity in the COVID-19 disease, caused by the SARS-CoV-2, which hijacks the host ribosome to preferentially translate its RNA genome. Such a protocol should be able to provide a high-throughput screening of clinical samples in a large population that would reach a statistical power for determining the impact of a specialized ribosome to specific characteristics of the disease. These characteristics may include host susceptibility, viral infectivity and transmissibility, severity of symptoms, antiviral treatment responses, and vaccine immunogenicity including its side effect and efficacy. In this study, several state-of-the-art techniques, in particular, chemical probing of ribosomal components or rRNA structures, proximity ligation to generate rRNA-mRNA chimeras for sequencing, nanopore gating of individual ribosomes, nanopore RNA sequencing and/or structural analyses, single-ribosome mass spectrometry, and microfluidic droplets for separating ribosomes or indexing rRNAs/mRNAs, are discussed. The key elements for further improvement and proper integration of the above techniques to potentially arrive at a high-throughput protocol for examining individual ribosomes and their mRNA substrates in a clinical setting are also presented.
Self-Pierce Riveting of Three Thin Sheets of Aluminum Alloy A5052 and 980 MPa Steel
Authors: Achira Satoshi , Abe Yohei , Mori Ken-ichiro
Published: January 2022

Self-pierce riveting of three thin sheets of 980 MPa steel and 5052 aluminum alloy was performed to investigate the effect of sheet configuration on the deforming behaviors of the sheets and the rivet and joint strength. When the lower sheet was aluminum alloy, the joining range was relatively wide, i.e., the interlock hooking the rivet leg tended to be large. In the sheet configuration in which the upper and lower sheets were A5052 and the middle sheet was 980 MPa steel, the rivet leg spread out moderately and the joint without defects was obtained. In the lower 980 MPa steel sheet, fracture tended to occur due to the low ductility of the lower sheet, and the joining range was narrow with the small interlock although the three sheets were joined by an appropriate die shape. In joint strength of joined three sheets, fracture occurred in the lower-strength aluminum alloy sheet if interlocks of about 300 μm and 150 μm could be formed in the lower aluminum alloy sheet and 980 MPa steel sheet, respectively.
Effect of Multi-Pass Power Spinning on Microstructure Homogenization and Mechanical-Property Strengthening of Ti2AlNb-Based Alloy Using Welded Tube Blank
Authors: Wang Sibing , Xu Wenchen , Wang Bo , Yang Guoping , Shan Debin
Published: January 2022

Long seamless tubes of Ti2AlNb-based alloys are difficult to manufacture through conventional forming methods. In this study, a multi-pass power spinning process was first utilized to fabricate thin-walled tube of Ti-22Al-24Nb-0.5Mo alloy using welded thick tube blank, assisted by on-line electro-magnetic induction heating to maintain high spinning temperature during the whole spinning process. After six-pass hot power spinning at 950 ± 30 °C, the microhardness difference of BM (base metal), HAZ (heat affect zone) and FZ (fusion zone) became much smaller, and the microhardness fluctuation ΔHV dropped to 32 from 122 of the as-welded joint due to the phase composition and microstructure homogenization. The grain size of B2 phase was refined to 0.4/0.6 μm from 2.7/10.8 μm of the as-received BM/FZ, respectively. Meanwhile, the B2 phase <111>B2//ND texture of the as-received rolled sheet weakened during multi-pass spinning due to recrystallization, which co-existed with <001>B2//ND texture in final pass. The ultimate tensile strength in axial/tangential direction was increased to 1245/1299 MPa from 1206/1010 MPa of the as-received rolled sheet, respectively, mainly due to the effect of fine grain strengthening. This study provides an effective way to manufacture high-performance tubular workpieces with low cost and high efficiency.
Positron Annihilation Spectroscopy Study of Metallic Materials after High-Speed Cutting
Authors: Li Jinquan , Laptev Roman , Bordulev Iurii , Siemek Krzysztof , Horodek Pawel , Shen Haolun , Lomygin Anton , Cui Jian
Published: January 2022

During high-speed cutting, a white layer is often produced on the machined surfaces after mechanical machining, seriously affecting the mechanical properties. These properties are related to the material structure and the defects induced by cutting. However, there is a lack of research on the atomic-scale defects of the white layer. This paper studied the influence of cutting parameters, namely the feed rate, cutting speed and cutting depth, on atomic-scale defects induced by high-speed cutting in GCr15 steel. Positron annihilation studies showed typical plastically deformed or tempered carbon steel defects with additional vacancy cluster components. The quantity of these clusters changed with cutting parameters. Furthermore, significant changes were observed in the subsurface region up to 1 µm, occurring as a result of simultaneous phase transformations, deformation and thermal impacts. The predominant accumulation of only one type of atomic-scale defect was not observed.
Numerical Simulation of Elastic Wave Field in Viscoelastic Two-Phasic Porous Materials Based on Constant Q Fractional-Order BISQ Model
Authors: Hu Ning , Wang Maofa , Qiu Baochun , Tao Yuanhong
Published: January 2022

The fractional-order differential operator describes history dependence and global correlation. In this paper, we use this trait to describe the viscoelastic characteristics of the solid skeleton of a viscoelastic two-phasic porous material. Combining Kjartansson constant Q fractional order theory with the BISQ theory, a new BISQ model is proposed to simulate elastic wave propagation in a viscoelastic two-phasic porous material. The corresponding time-domain wave propagation equations are derived, and then the elastic waves are numerically simulated in different cases. The integer-order derivatives are discretised using higher-order staggered-grid finite differences, and the fractional-order time derivatives are discretised using short-time memory central differences. Numerical simulations and analysis of the wave field characterisation in different phase boundaries, different quality factor groups, and multilayered materials containing buried bodies are carried out. The simulation results show that it is feasible to combine the constant Q fractional-order derivative theory with the BISQ theory to simulate elastic waves in viscoelastic two-phasic porous materials. The combination can better describe the viscoelastic characteristics of the viscoelastic two-phasic porous materials, which is of great significance for further understanding the propagation mechanism of elastic waves in viscoelastic two-phasic porous materials and viscoelastic two-phasic porous materials containing buried bodies. This paper provides a theoretical forward simulation for fine inversion and reconstruction of layer information and buried body structure in viscoelastic two-phasic porous materials.
Changes in Microstructure and Abrasion Resistance during Miller Test of Hadfield High-Manganese Cast Steel after the Formation of Vanadium Carbides in Alloy Matrix
Authors: Tęcza Grzegorz
Published: January 2022

Hadfield cast steel is characterized by high wear resistance, but this is only when it is subjected to the effect of dynamic loads. During unloaded abrasion, e.g., sand abrasion, its wear resistance is very low and comparable to the wear of carbon cast steel. To increase the wear resistance of this alloy for operation under the conditions of low pressure or low stress, primary vanadium carbides were produced by the metallurgical process to obtain a two-phase structure after alloy solidification. Compared to samples made of Hadfield cast steel, the primary, very hard carbides, evenly distributed in an austenitic or austenitic-martensitic matrix, increase (at least three times) the wear resistance of samples tested in an abrasive mixture of silicon carbide and water. The changes in microstructure and hardness obtained in alloys after heat treatment (quenching at 1000–1150 °C in water and tempering at 600 °C) are presented. The bulk hardness of the matrix ranged from 370 HV to 660 HV. After heat treatment, the secondary, dispersed vanadium carbides, precipitated in the alloy matrix.
New Concept for the Facile Fabrication of Core–Shell CuO@CuFe2O4 Photocathodes for PEC Application
Authors: Trinh Linh , Bienkowski Krzysztof , Wróbel Piotr , Pisarek Marcin , Parzuch Aleksandra , Nawaz Nabila , Solarska Renata
Published: January 2022

The CuO@CuFe2O4 core–shell structure represents a new family of photocatalysts that can be used as photoelectrodes that are able to produce hydrogen under a broad spectrum of visible light. Herein, we report a novel approach for the production of this active film by the thermal conversion of CuFe Prussian Blue Analogues. The outstanding photoelectrochemical properties of the photocathodes of CuO@CuFe2O4 were studied with the use of combinatory photo-electrochemical instrumental techniques which proved that the electrodes were stable over the whole water photolysis run under relatively positive potentials. Their outstanding performance was explained by the coupling of two charge transfer mechanisms occurring in core–shell architectures.
Development of the Platform for Three-Dimensional Simulation of Additive Layer Manufacturing Processes Characterized by Changes in State of Matter: Melting-Solidification
Authors: Svyetlichnyy Dmytro S.
Published: January 2022

A new platform for three-dimensional simulation of Additive Layer Manufacturing (ALM) processes is presented in the paper. The platform is based on homogeneous methods—the Lattice Boltzmann Method (LBM) with elements of Cellular Automata (CA). The platform represents a new computer-based engineering technique primarily focused on Selective Laser Melting (SLM) technology. Innovative computational strategies and numerical algorithms for simulation and analysis of entire powder bed-based technology with changes in state of matter (melting-solidification) are presented in the paper. The models deal mainly with heat transfer, melting and solidification, and free-surface flow. Linking LBM and CA into a complex holistic model allows for complete full-scale simulations avoiding complicated interfaces. The approach is generic and can be applied to different multi-material powder bed-based SLM processes. A methodology for the adaptation of the model to the real material (Ti-6Al-4V alloy) and processing parameters is presented. The paper presents the first quantitative results obtained on the platform and shows the ability of the model to simulate and analyze a very complex technology, entirely without a complicated interface between the sub-models. It solves the large-scale problem connected with computer-aided design and analysis of new multi-passes and multi-materials processes.
A New Anorganic Equine Bone Substitute for Oral Surgery: Structural Characterization and Regenerative Potential
Authors: Addis Alessandro , Canciani Elena , Campagnol Marino , Colombo Matteo , Frigerio Christian , Recupero Daniele , Dellavia Claudia , Morroni Marco
Published: January 2022

Different xenogeneic inorganic bone substitutes are currently used as bone grafting materials in oral and maxillo-facial surgery. The aim of the present study was to determine the physicochemical properties and the in vivo performance of an anorganic equine bone (AEB) substitute. AEB is manufactured by applying a process involving heating at >300 °C with the aim of removing all the antigens and the organic components. AEB was structurally characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray fluorescence (XRF), and Fourier-transformed infrared (FT-IR) spectroscopy and compared to the anorganic bovine bone (ABB). In order to provide a preliminary evaluation of the in vivo performance of AEB, 18 bone defects were prepared and grafted with AEB (nine sites), or ABB (nine sites) used as a control, in nine Yucatan Minipigs. De novo bone formation, residual bone substitute, as well as local inflammatory and tissue effects were histologically evaluated at 30 and 90 days after implantation. The structural characterization showed that the surface morphology, particle size, chemical composition, and crystalline structure of AEB were similar to cancellous human bone. The histological examination of AEB showed a comparable pattern of newly formed bone and residual biomaterial to that of ABB. Overall, the structural data and pre-clinical evidence reported in the present study suggests that AEB can be effectively used as bone grafting material in oral surgery procedures.
Evaluation of the Radiation-Protective Properties of Bi (Pb)–Sr–Ca–Cu–O Ceramic Prepared at Different Temperatures with Silver Inclusion
Authors: Hannachi Essia , Mahmoud K. A. , Almuqrin Aljawhara H. , Sayyed M. I. , Slimani Yassine
Published: January 2022

The influences of the sintering process and AgNO3 addition on the phase formation and radiation shielding characteristics of Bi1.6Pb0.4Sr2Ca2Cu3O10 were studied. Three ceramics (code: C0, C1, and C2) were prepared as follows: C0 was obtained after calcination and only one sintering step, C1 was obtained after calcination and two sintering cycles, and C2 was prepared after the addition of AgNO3 at the beginning of the final sintering stage. C2 displayed the maximum volume fraction of the Bi-2223 phase (76.4 vol%), the greatest crystallite size, and high density. The linear mass attenuation coefficient (µ) has been simulated using the Monte Carlo simulation. The µ values are high at 15 keV (257.2 cm−1 for C0, 417.57 cm−1 for C1, and 421.16 cm−1 for C2), and these values dropped and became 72.58, 117.83 and 133.19 cm−1 at 30 keV. The µ value for the ceramics after sintering is much higher than the ceramic before sintering. In addition, the µ value for C2 is higher than that of C1, suggesting that the AgNO3 improves the radiation attenuation performance for the fabricated ceramics. It was demonstrated that the sintering and AgNO3 addition have a considerable influence on the ceramic thickness required to attenuate the radiation.
The Effect of Active Additives and Coarse Aggregate Granulometric Composition on the Properties and Durability of Pervious Concrete
Authors: Banevičienė Vilma , Malaiškienė Jurgita , Boris Renata , Zach Jiri
Published: January 2022

Pervious concrete (PCO) has many advantages and applications, such as water pooling reduction, noise attenuation, replenishment of groundwater reserves, etc. However, the use of pervious concrete is limited due to its low compressive strength and durability, especially as a result of portlandite leaching from concrete exposed to flowing water. The effects of active additives (nano SiO2 (NS) spent catalyst generated at the fluid catalytic cracking unit (FCCCw) and paper sludge waste burned at 700 °C (PSw)) along with particle size distribution of the coarse aggregate on the properties and durability of pervious concrete were determined in the research. Active additives used in the binder were found to reduce portlandite leaching from concrete exposed to flowing water to significantly increase the resistance of concrete to freezing and thawing cycles and to increase sound absorption, compressive strength and infiltration rate. In addition, industrial waste (FCCCw and PSw) used as active additives significantly reduced the use of clinker in concrete applied in the construction of water pervious systems. The coarse aggregate size distribution had the greatest effect on the density, ultrasound pulse velocity (UPV), porosity, compressive strength and infiltration rate of pervious concrete.
Carbon Nanomaterials (CNMs) and Enzymes: From Nanozymes to CNM-Enzyme Conjugates and Biodegradation
Authors: Rozhin Petr , Abdel Monem Gamal Jada , Giordani Silvia , Marchesan Silvia
Published: January 2022

Carbon nanomaterials (CNMs) and enzymes differ significantly in terms of their physico-chemical properties—their handling and characterization require very different specialized skills. Therefore, their combination is not trivial. Numerous studies exist at the interface between these two components—especially in the area of sensing—but also involving biofuel cells, biocatalysis, and even biomedical applications including innovative therapeutic approaches and theranostics. Finally, enzymes that are capable of biodegrading CNMs have been identified, and they may play an important role in controlling the environmental fate of these structures after their use. CNMs’ widespread use has created more and more opportunities for their entry into the environment, and thus it becomes increasingly important to understand how to biodegrade them. In this concise review, we will cover the progress made in the last five years on this exciting topic, focusing on the applications, and concluding with future perspectives on research combining carbon nanomaterials and enzymes.
Numerical Simulation and Experimental Verification of Residual Stress in the Welded Joints of Weldolet–Branch Pipe Dissimilar Steels
Authors: Mai Chunliang , Hu Xue , Zhang Lixin , Song Bao , Zheng Xiongfei
Published: January 2022

It is well known that welding dissimilar metals can play the advantages and characteristics of those different metals, but it is easy to encounter some problems. In this paper, the thermomechanical behavior of the weldolet–branch dissimilar steel joints in different welding cases is analyzed by establishing a three-dimensional finite element model, and the predicted thermal cycling and residual stresses are verified using experimental tools. The results show that the high temperature area and the heat affected zone on the side of the branch pipe are larger, and there is a large stress gradient at the fusion line on both sides of the weld. Too high or too low temperature between welding layers will cause large residual stress, thus, 200 °C is more suitable for the welding of weldolet–branch joints. The residual stresses of path-1, path-2 and path-3 have similar distributions at 0° and 180° sections, and the circumferential and axial residual stresses on the inner surface are larger than those on the outer surface. The residual stress on the inner and outer surfaces of path-3 is smaller than that of path-1 and path-2 at the 90° and 270° sections as a whole, and the residual stress at the 90° section reaches the minimum.
Gelatin- and Papaya-Based Biodegradable and Edible Packaging Films to Counter Plastic Waste Generation
Authors: Ashfaq Jaweria , Channa Iftikhar Ahmed , Shaikh Asif Ahmed , Chandio Ali Dad , Shah Aqeel Ahmed , Bughio Bushra , Birmahani Ashfaque , Alshehri Sultan , Ghoneim Mohammed M.
Published: January 2022

Most of the food packaging materials used in the market are petroleum-based plastics; such materials are neither biodegradable nor environmentally friendly and require years to decompose. To overcome these problems, biodegradable and edible materials are encouraged to be used because such materials degrade quickly due to the actions of bacteria, fungi, and other environmental effects. In this work, commonly available household materials such as gelatin, soy protein, corn starch, and papaya were used to prepare cost-effective lab-scale biodegradable and edible packaging film as an effective alternative to commercial plastics to reduce waste generation. Prepared films were characterized in terms of Fourier transform infrared spectroscopy (FTIR), water vapor transmission rate (WVTR), optical transparency, and tensile strength. FTIR confirmed the addition of papaya and soy protein to the gelatin backbone. WVTR of the gelatin-papaya films was recorded to be less than 50 g/m2/day. This water vapor barrier was five times better than films of pristine gelatin. The gelatin, papaya, and soy protein films exhibited transparencies of around 70% in the visible region. The tensile strength of the film was 2.44 MPa, which improved by a factor of 1.5 for the films containing papaya and soy protein. The barrier qualities of the gelatin and gelatin-papaya films maintained the properties even after going through 2000 bending cycles. From the results, it is inferred that the prepared films are ideally suitable for food encapsulation and their production on a larger scale can considerably cut down the plastic wastage.
Impact of Electric Vehicles on a Power Line with Photovoltaic Power Plants Connected
Authors: Dulău Lucian Ioan , Bică Dorin
Published: January 2022

Electric vehicles (EVs) are currently popular, and their number is growing; therefore, they have an impact on the power system. In this paper, the impact of electric vehicles on a power line connected to photovoltaic (PV) power plants regarding the power losses and voltage level is presented. The study is performed for a power line located in Mureș County, Romania, to which two photovoltaic power plants are connected. Three supply options are available for the power line, which supplies 15 loads. The power demand of the loads is determined with the power meters installed at the load premises. Electric vehicles are also considered to be connected in different points along the power line at the buses with the lowest voltage level. The results give the power losses and voltage levels for the case of when the PV power plants and EVs are connected to the power line, compared with the case when the EVs are not connected to the power line. The power losses were 400% higher in the case where the EVs were connected when the power demand was higher, while the voltage level was 2% lower if the EVs were connected.
Introducing a Novel Method for Smart Expansive Systems’ Operation Risk Synthesis
Authors: Zhigirev Nikolay , Bochkov Alexander , Kuzmina Nataliya , Ridley Alexandra
Published: January 2022

In different areas of human activity, the need to choose optimal (rational) options for actions from the proposed alternatives inevitably arises. In the case of retrospective statistical data, risk analysis is a convenient tool for solving the problem of choice. However, when planning the growth and development of complex systems, a new approach to decision-making is needed. This article discusses the concept of risk synthesis when comparing alternative options for the development of a special class of complex systems, called smart expansive systems, by the authors. “Smart” in this case implies a system capable of ensuring a balance between its growth and development, considering possible external and internal risks and limitations. Smart expansive systems are considered in a quasi-linear approximation and in stationary conditions of problem-solving. In general, when the alternative to comparison is not the object itself, but some scalar way of determining risks, the task of selecting the objects most at risk is reduced to assessing the weights of factors affecting the integral risk. As a result, there is a complex task of analyzing the risks of objects, solved through the amount by which the integral risk can be minimized. Risks are considered as anti-potentials of the system development, being retarders of the reproduction rate of the system. The authors give a brief description of a smart expansive system and propose approaches to modeling the type of functional dependence of the integral risk of functioning of such a system on many risks, measured, as a rule, in synthetic scales of pairwise comparisons. The solution to the problem of reducing the dimension of influencing factors (private risks) using the vector compression method (in group and inter-scale formulations) is described. This article presents an original method for processing matrices of incomplete pairwise comparisons with indistinctly specified information, based on the idea of constructing reference-consistent solutions. Examples are provided of how the vector compression method can be applied to solve practical problems.
Understanding Interaction Patterns within Deep-Sea Microbial Communities and Their Potential Applications
Authors: Nawaz Muhammad Zohaib , Subin Sasidharan Raghul , Alghamdi Huda Ahmed , Dang Hongyue
Published: January 2022

Environmental microbes living in communities engage in complex interspecies interactions that are challenging to decipher. Nevertheless, the interactions provide the basis for shaping community structure and functioning, which is crucial for ecosystem service. In addition, microbial interactions facilitate specific adaptation and ecological evolution processes particularly essential for microbial communities dwelling in resource-limiting habitats, such as the deep oceans. Recent technological and knowledge advancements provide an opportunity for the study of interactions within complex microbial communities, such as those inhabiting deep-sea waters and sediments. The microbial interaction studies provide insights into developing new strategies for biotechnical applications. For example, cooperative microbial interactions drive the degradation of complex organic matter such as chitins and celluloses. Such microbiologically-driven biogeochemical processes stimulate creative designs in many applied sciences. Understanding the interaction processes and mechanisms provides the basis for the development of synthetic communities and consequently the achievement of specific community functions. Microbial community engineering has many application potentials, including the production of novel antibiotics, biofuels, and other valuable chemicals and biomaterials. It can also be developed into biotechniques for waste processing and environmental contaminant bioremediation. This review summarizes our current understanding of the microbial interaction mechanisms and emerging techniques for inferring interactions in deep-sea microbial communities, aiding in future biotechnological and therapeutic applications.
Biomechanics of Double Poling in Paralympic Cross-Country Skiing—A Cross-Sectional Study Comparing the Standing and Sitting Positions in Healthy Male Subjects
Authors: Sasadai Junpei , Maeda Noriaki , Morikawa Masanori , Komiya Makoto , Shimizu Reia , Fukui Kazuki , Yoshimi Mitsuhiro , Kono Yoshifumi , Urabe Yukio
Published: January 2022

Background and Objectives: Double poling is an important fundamental skill required for cross-country skiing in able-bodied athletes and in those with physical disabilities. Meanwhile, the performance improvement and injury prevention related to double poling requires a thorough assessment, whereas the scapular and shoulder kinematics in different postural conditions remain to be clarified. The main purpose of this study was to evaluate the biomechanics during cross-country ski double poling in the standing and sitting positions. Materials and Methods: Eleven participants underwent kinematic assessments of the shoulder girdle during double poling on a ski ergometer with an electromagnetic tracking device. The cycle rate, stroke length, stroke speed, thorax motion relative to pelvis, scapular motions relative to thorax, humeral motions relative to thorax, and humeral motions relative to scapula were calculated for five double-poling cycles. Results: In the sitting position, the angles of humerothoracic elevation were 18 degrees larger and glenohumeral elevation 13 degrees larger than in the standing position at the upward point and range of motion. Conclusions: The study revealed that double poling in the sitting condition increased the humerothoracic and glenohumeral elevation angle to secure the poling margin. If these are excessive, there is a risk of shoulder injuries such as subacromial impingement.
Evaluation of CADI Low Alloyed with Chromium for Camshafts Application
Authors: Cruz Ramírez Alejandro , Colin García Eduardo , Chávez Alcalá José Federico , Téllez Ramírez Jaime , Magaña Hernández Antonio
Published: January 2022

Different processing routes have been developed to increase the strength and hardness of camshafts for automotive applications. In this work, two carbidic austempered ductile irons (CADIs), alloyed with 0.2 and 0.4 wt% Cr, were evaluated to determine their suitability in the camshaft production by microscopy techniques and mechanical tests. The CADIs were produced at austempering temperatures of 265 and 305 °C, during 30, 60, 90, and 120 min. The microstructural characterization was carried out by optical microscopy, while Rockwell C Hardness, tensile, Charpy impact, and block-on-ring wear loss tests were evaluated for mechanical characterization from the camshaft and standard keel block. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by X-ray diffraction measurements. The process window was found in the range from 60 to 120 min, for both austempering temperatures, while the highest amount of ausferrite was obtained at 90 min. The formation of carbides was increased as the chromium content was increased. The highest hardness (49 HRC) and wear resistance (0.252 mm3) were obtained for the lower austempering temperature (265 °C, 90 min) and higher chromium content (0.4%). The highest austempering temperature (305 °C, 90 min) and lowest chromium content (0.2%) allow for obtaining the highest toughness (22.91 J) and elongation (4.2%), while the highest tensile strength (1027 MPa) was obtained for the CADI containing 0.2% Cr heat-treated to 265 °C.
Influence of Deposition Strategies on Residual Stress in Wire + Arc Additive Manufactured Titanium Ti-6Al-4V
Authors: Ahmad Bilal , Zhang Xiang , Guo Hua , Fitzpatrick Michael E. , Neto Leonor MacHado Santos Carvalho , Williams Stewart
Published: January 2022

Wire + arc additive manufacturing (WAAM) is a modern manufacturing process that has opened new possibilities for rapid builds and reductions in material wastage. This paper explores residual stress in WAAM Ti-6Al-4V walls built using three different deposition strategies: single bead, parallel path, and oscillation path. The effect of interlayer hammer peening and interlayer temperature was investigated for the single bead walls. We also examined the residual stress in compact-tension (C(T)) coupons extracted from large builds (walls) with crack orientation either parallel with or perpendicular to the build direction. This type of sample is often used for the measurement of the fatigue crack growth rate. The contour method was used for experimental determinations of residual stress. In addtion, residual stress in the C(T) coupons was estimated by finite element (FE) analysis. A good agreement was achieved between the contour method and FE analysis. The oscillation-path wall had the lowest residual stress values. For the single bead walls built with various process conditions, residual stress was significantly reduced after removing the substrate. A interlayer temperature of 110 °C resulted in much higher residual stress values in the wall (both tensile and compressive) compared to the continuous build, with much higher interlayer temperature.
Assessment of Fruit and Vegetables Intake with Biomarkers in Children and Adolescents and Their Level of Validation: A Systematic Review
Authors: Yuan Li , Muli Samuel , Huybrechts Inge , Nöthlings Ute , Ahrens Wolfgang , Scalbert Augustin , Floegel Anna
Published: January 2022

Fruit and vegetables (FV) are part of a healthy diet and should be frequently consumed already at a young age. However, intake of FV is difficult to assess in children and adolescents due to various misreporting aspects. Thus, measurement of dietary biomarkers may be a promising alternative to assess FV intake more objectively at young age. To date, dietary biomarkers have been primarily studied in adults, and research focused on their usefulness in children is scarce. However, clinical studies have revealed important differences between children and adults, most importantly in their gut microbiome composition, resulting in differences in postprandial metabolism, as well as in food choices and meal compositions that may influence individual biomarker levels. Therefore, the present review aimed to identify biomarkers of FV intake (BFVI) currently available in children and adolescents and to explore whether there are any differences in the BFVI profile above between children and adolescents and adults. In addition, the current level of validation of BFVI in children and adolescents was examined. In total, 28 studies were eligible for this review, and 18 compounds were identified as potential biomarkers for FV intake in children and adolescents. Carotenoid concentration in skin was a valuable biomarker for total FV intake for both children and adult populations. Common BFVI in blood in adults (e.g., carotenoids and vitamin C) showed inconsistent results in children and adolescents. Biomarkers particularly useful in children included urinary hippuric acid as a biomarker of polyphenolic compound intake originating from FV and the combination of N-methylnicotinic acid and acetylornithine as a biomarker of bean intake. Further studies are needed to assess their kinetics, dose–response, and other validation aspects. There is limited evidence so far regarding valid BFVI in children and adolescents. Thus, to put BFVI into practice in children and adolescents, further studies, particularly based on metabolomics, are needed to identify and validate BFVI that can be used in future epidemiological studies.
Longitudinal Metabolomic Analysis Reveals Gut Microbial-Derived Metabolites Related to Formula Feeding and Milk Sensitization Development in Infancy
Authors: Tang Ching-Min , Lin Gigin , Chiang Meng-Han , Yeh Kuo-Wei , Huang Jing-Long , Su Kuan-Wen , Tsai Ming-Han , Hua Man-Chin , Liao Sui-Ling , Lai Shen-Hao , Chiu Chih-Yung
Published: January 2022

Early exposure to formula milk increases the likelihood of cow’s milk sensitization and food allergies in the later childhood. However, the underlying mechanisms are multifactorial and unclear. Fifty-five children from a follow-up birth cohort study were grouped into exclusive breastfeeding (EBF, n = 33) and formula feeding (EFF, n = 22) in the first six months of life. Urinary metabolites were longitudinally assessed and analyzed at 6 months, 1, and 2 years of age using 1H-nuclear magnetic resonance (NMR) spectroscopy. Integrated analysis of metabolic profiling associated with formula feeding and milk sensitization related to IgE reactions was also investigated. Twenty-two metabolites were significantly obtained in the EFF set at age 0.5, whereas nine metabolites were predominantly obtained in the milk sensitization set at age 1. A subsequent analysis of metabolic change from 6 months to age 1 identified eight metabolites, including 3-methyl-2-oxovaleric acid, glutarate, lysine, N-phenylacetylglycine, N,N-dimethylglycine, 3-indoxysulfate, 2-oxoglutaric acid, and pantothenate associated with formula feeding and milk sensitization with same trend variation. Among them, 3-indoxysulfate, N-phenylacetylglycine, and N,N-dimethylglycine were gut microbial-derived without IgE association. By contrast, 3-methyl-2-oxovaleric acid, glutarate, and lysine were IgE related associated with formula feeding contributing to milk sensitization (p < 0.05). Longitudinal urinary metabolomic analysis provides molecular insight into the mechanism of formula feeding associated with milk sensitization. Gut microbial-derived metabolites associated with formula feeding and IgE associated metabolites related to branched-chain amino acid metabolism play roles in developing sensitization and allergic symptoms in response to formula feeding.
Investigation of the Dynamics of Cavitation Bubbles in a Microfluidic Channel with Actuations
Authors: Shang Xiaopeng , Huang Xiaoyang
Published: January 2022

This work presents experimental and numerical studies on the dynamics of cavitation bubbles in a nozzle-shaped microfluidic channel with PZT (lead-zirconate-titanate) actuations. It is found that a cloud of bubbles can be generated near the center of the microfluidic channel when the actuation voltage is larger than a threshold at 1 kHz. After being generated, the bubbles under actuations oscillate radially with violent expansion and compression, and simultaneously translate upstream towards the opening of the nozzle. Along with radial oscillation and translation, the bubbles undergo frequent and drastic coalescence and breakup, leading to vigorous churning of surrounding liquids. The pressure variation and distribution in the microchannel are calculated by numerical simulation in Ansys Fluent, and results show that there is a low-pressure zone inside the microfluidic channel within each cycle of the actuation period, which is responsible for bubble generation observed in the experiments. The method of bubble generation in this study is novel and can be applied for the enhancement of heat and mass transfer in microfluidic operations.
Architecture of Computing System based on Chiplet
Authors: Shan Guangbao , Zheng Yanwen , Xing Chaoyang , Chen Dongdong , Li Guoliang , Yang Yintang
Published: January 2022

Computing systems are widely used in medical diagnosis, climate prediction, autonomous vehicles, etc. As the key part of electronics, the performance of computing systems is crucial in the intellectualization of the equipment. The conflict between performance, efficiency, and cost can be solved by choosing an appropriate computing system architecture. In order to provide useful advice and instructions for the designers to fabricate high-performance computing systems, this paper reviews the Chiplet-based computing system architectures, including computing architecture and memory architecture. Firstly, the computing architecture used for high-performance computing, mobile, and PC is presented and summarized. Secondly, the memory architecture based on mainstream memory and emerging non-volatile memory used for data storing and processing are introduced, and the key parameters of memory are compared and discussed. Finally, this paper is concluded, and the future perspectives of computing system architecture based on Chiplet are presented.
Multi-Modal Microfluidics (M3) for Sample Preparation of Liquid Biopsy: Bridging the Gap between Proof-of-Concept Demonstrations and Practical Applications
Authors: Liu Yaoping , Wang Wei
Published: January 2022

Liquid biopsy, the technique used to shed light on diseases via liquid samples, has displayed various advantages, including minimal invasiveness, low risk, and ease of multiple sampling for dynamic monitoring, and has drawn extensive attention from multidisciplinary fields in the past decade. With the rapid development of microfluidics, it has been possible to manipulate targets of interest including cells, microorganisms, and exosomes at a single number level, which dramatically promotes the characterization and analysis of disease-related markers, and thus improves the capability of liquid biopsy. However, when lab-ready techniques transfer into hospital-applicable tools, they still face a big challenge in processing raw clinical specimens, which are usually of a large volume and consist of rare targets drowned in complex backgrounds. Efforts toward the sample preparation of clinical specimens (i.e., recovering/concentrating the rare targets among complex backgrounds from large-volume liquids) are required to bridge the gap between the proof-of-concept demonstrations and practical applications. The throughput, sensitivity, and purity (TSP performance criteria) in sample preparation, i.e., the volume speed in processing liquid samples and the efficiencies of recovering rare targets and depleting the backgrounds, are three key factors requiring careful consideration when implementing microfluidic-based liquid biopsy for clinical practices. Platforms based on a single microfluidic module (single-modal microfluidics) can hardly fulfill all the aforementioned TSP performance criteria in clinical practices, which puts forward an urgent need to combine/couple multiple microfluidic modules into one working system (i.e., multi-modal microfluidics, M3) to realize practically applicable techniques for the sample preparation of liquid biopsy. This perspective briefly summarizes the typical microfluidic-based liquid biopsy techniques and discusses potential strategies to develop M3 systems for clinical practices of liquid biopsy from the aspect of sample preparation.
Three Frequency Up-Converting Piezoelectric Energy Harvesters Caused by Internal Resonance Mechanism: A Narrative Review
Authors: Liu Jian , Lu Yongling , Wang Zhen , Li Sen , Wu Yipeng
Published: January 2022

Low frequency mechanical vibrations are ubiquitous in practical environments, and how to efficiently harvest them with piezoelectric materials remains a challenge. Frequency up-conversion strategies—up-converting low frequency vibrations to high frequency self-oscillations—can improve the power density of piezoelectric materials. This paper mainly introduces a kind of frequency which up-converts piezoelectric energy harvesters based on an internal resonance mechanism, compared with the other mechanisms caused by mechanical impact, mechanical plucking, etc.; the internal resonance-based harvesters can up-convert the frequency under a condition of lower excitation level, less energy loss, and less wideband operation bandwidth. Benefits to practical vibrations also exist in these multi-degree-of-freedom nonlinear dynamic systems. Moreover, the value of the frequency up-conversion factor based on the 1:2:6 internal resonance mechanism can reach as much as six so far, which is also a quite a high frequency up-conversion value.
Numerical Modeling of the Effect of Cutting-Edge Radius on Cutting Force and Stress Concentration during Machining
Authors: Li Peng , Chang Zhiyong
Published: January 2022

Cutting is the primary method of material removal, and the quality of machined parts depends on the geometry of cutting tools. In this paper, a new cutting force coefficient model is established, revealing the influence of cutting-edge radius on the cutting process. The effects of cutting-edge radius on the shear angle and cutting force components are analyzed by finite element simulations. A series of simulations is conducted, and the results show that with increased cutting-edge radius, the shear angle decreases nonlinearly, and the cutting force increases gradually. Additionally, the growth rate of the feed force caused by increasing the cutting-edge radius is higher than that of the tangential force. Furthermore, the stress concentration area of the machined surface extends from the surface to the subsurface as the cutting-edge radius increases. The results of this research show that changing the cutting edge affects the cutting force component, shear angle, and stress concentration range during the cutting process. These results provide a theoretical reference for predicting the residual stress in parts.
Microstructure Evolution and Mechanical Properties of Needle-like ZrB2 Reinforced Cu Composites Manufactured by Laser Direct Energy Deposition
Authors: Lv Xiangzhe , Zhan Zaiji , Cao Haiyao
Published: January 2022

Laser additive manufacturing is an advanced material preparation technology, which has been widely used to prepare various materials, such as polymers, metals, ceramics and composites. Zirconium diboride (ZrB2) reinforced copper composite material was fabricated using laser direct energy deposition technology. The microstructure and phase composition of the composite material were analyzed, and the influence of laser energy density on the microstructure and mechanical properties of composite materials was discussed. The results showed that the needle-like ZrB2 ceramic reinforcement was successfully synthesized via an in-situ synthesis reaction. The composites were mainly composed of needle-like ZrB2, Ni dendrites and a Cu matrix. The morphological changes of Ni dendrites could be observed at the interface inside the composite material: cellular crystals → large-sized columnar dendrites → small-sized dendrites (along the solidification direction). The continuous Ni dendritic network connected the ZrB2 reinforcements together, which significantly improved the mechanical properties of the composite material. At a laser energy density of 0.20 kJ/mm2, the average microhardness of the composite material reached 294 HV0.2 and the highest tensile strength was 535 MPa. With the laser energy density increased to 0.27 kJ/mm2, the hardness and tensile strength decreased and the elongation of the Cu composites increased due to an increase in the size of the ZrB2 and a decrease in the continuity of the Ni dendritic.