bluuebunny/crossref_metadata_2025 huggingface dataset:
A Friction Fluctuation Model of Rolling Guideways
Authors: Kono Daisuke , Osumi Tomoyuki
Published: August 2021

Linear ball guideways are widely employed in machine tool drive systems. Friction fluctuation of linear ball guideways cause the fluctuation of feed rate which results in the contour error in synchronous motions using several feed drives. A model-based systematic methodology to design the raceway profile is demanded to reduce the friction fluctuation of rolling guideways. In this study, a model to estimate the rolling resistance fluctuation of a ball sandwiched by two raceways was proposed. The rolling resistance fluctuation was estimated from the contact angle between the ball and raceways. The contact angle was obtained from the surface profile of the raceway. The estimation accuracy of the proposed model was verified by comparing measured and estimated rolling resistances. The raceway that was finished by face milling with a R-bite was used in the experiment to have rolling resistance fluctuation due to a periodic surface profile. The experimental results showed that the rolling resistance fluctuation could be estimated by the proposed model with 30% amplitude error at maximum. The variation of the rolling resistance was influenced by the phase difference between the upper and lower raceway profiles. The rolling resistance variation could be decreased to 1/3 when the phase difference was 1/2 period of the periodic profile component.
Effect of Laser Forming on the Energy Absorbing Behavior of Metal Foams
Authors: Zhang Tom , Liu Yubin , Yao Y. Lawrence
Published: August 2021

Metal foam is light in weight and exhibits an excellent impact absorbing capability. Laser forming has emerged as a promising process in shaping metal foam plates into desired geometry. While the feasibility and shaping mechanism has been studied, the effect of the laser forming process on the mechanical properties and the energy absorbing behavior in particular of the formed foam parts has not been well understood. This study comparatively investigated such effect on as-received and laser formed closed-cell aluminum alloy foam. In quasi-static compression tests, attention was paid to the changes in the elastic region. Imperfections near the laser irradiated surface were closely examined and used to help elucidate the similarities and differences in as-received and laser formed specimens. Similarly, from the impact tests, the dynamically induced deformation and crush band formation were investigated with a modified Charpy impact test scheme. Differences in specific energy absorption were studied and were related to the defects formed during laser forming process. The relative density distribution and evolution of foam specimens were numerically investigated. Laser induced imperfections lead to very minor decrease in the energy absorbing ability of the metal foam, and laser forming still remain as a viable shaping process for metal foams.
Discrete-Element Simulation of Powder Spreading Process in Binder Jetting, and the Effects of Powder Size
Authors: Clares Ana Paula , Manogharan Guha
Published: August 2021

Binder Jetting has gained particular interest amongst Additive Manufacturing (AM) techniques because of its wide range of applications, broader feasible material systems, and absence of rapid melting-solidification issues present in other AM processes. Understanding and optimizing printing parameters during the powder spreading process is essential to improve the quality of the final part. In this study, a Discrete Element Method (DEM) simulation is employed to evaluate the powder packing density, flowability, and porosity during powder spreading process utilizing three different powder groups. Two groups are formed with monoidal size distributions (75–84 μm and 100–109 μm), and the third one consisting of a bimodal distribution (50 μm + 100 μm).

A thorough investigation into the effects of powder size distribution during the powder spreading step in a binder jetting process is conducted using ceramic foundry sand. It was observed that coarser particles result in higher flowability (62% decrease in repose angle) than finer ones due to the cohesion effect present in the latter. A bimodal size distribution yields the highest packing density (8% increase) and lowest porosity (∼12% reduction) in the powder bed, as the finer particles fill in the voids created between the coarser ones. Findings from this study are directly applicable to binder-jetting AM process, and also offer new insights for AM powder manufacturers.
Electrically Assisted Wire Drawing Polarity Effects
Authors: Grimm Tyler J. , Mears Laine
Published: August 2021

Electrically assisted manufacturing is the direct application of an electric current or field to a workpiece during a manufacturing operation. In addition to resistive heating, various anomalous effects have been observed experimentally. Since its conception in the 1950s, scientists continue to debate the existence of these so called electroplastic effects (EPEs) due to conflicted results shown throughout literature. A popular theory of electroplasticity is the electron wind, which postulates that there is a transfer of momentum between electrons and dislocations, which assists their motion during deformation. Though refuted both mathematically and experimentally in other types of tests, the electron wind theory, and therefore the existence of electroplasticity, is interestingly supported by the existence of polarity effects in wire drawing.

A detailed review of the literature that has shown polarity effects in wire drawing is conducted. While the authors of these publications failed to fully disclose all test parameters, requiring several assumptions to be made, it appears that no mathematical/logical trends could be established. It is hypothesized herein that the velocity of the wire in a wire drawing application can influence the drift velocity of electrons, thereby increasing or decreasing current flow explicitly through the moving section of the wire. In order to test this hypothesis, a fixture was constructed which is capable of passing a current through a moving wire at common wire drawing speeds. Modern sensing equipment was used to measure various electrical parameters during testing. The wire speed effect hypothesis was refuted by experimental testing. While the results of experimental testing thus far indicate the existence of electroplasticity, further testing that includes drawing and force measurements must be conducted in order to fully conclude its existence in the wire drawing application.
Designing an Interchangeable Multi-Material Nozzle System for 3D Bioprinting Process
Authors: Nelson Cartwright , Tuladhar Slesha , Habib Md Ahasan
Published: August 2021

Three-dimensional bioprinting is a rapidly growing field attempting to recreate functional tissues for medical and pharmaceutical purposes. Development of functional tissue requires deposition of multiple biomaterials encapsulating multiple cell types i.e. bio-ink necessitating switching ability between bio-inks. Existing systems use more than one print head to achieve this complex interchangeable deposition, which decreases efficiency, structural integrity, and accuracy. In this research, we developed a nozzle system capable of switching between multiple bio-inks with continuous deposition ensuring the minimum transition distance so that precise deposition transitioning can be achieved. Finally, the effect of rheological properties of different bio-material compositions on the transition distance is investigated by fabricating the sample scaffolds.
The Influence of Carbon Nanotubes and Reprocessing on the Morphology and Properties of High-Density Polyethylene/Carbon Nanotube Composites
Authors: Stan Felicia , Sandu Ionut-Laurentiu , Turcanu Adriana-Madalina , Stanciu Nicoleta-Violeta , Fetecau Catalin
Published: August 2021

This study investigates virgin and recycled high-density polyethylene/multi-walled carbon nanotube (HDPE/MWCNT) composites using thermo-physical and mechanical characterization techniques to generate knowledge and understand recyclability of these composites. Firstly, virgin samples with 0.1–5 wt.% of MWCNTs were prepared by injection molding. Then, the HDPE/MWCNT composite waste was mechanically recycled and consecutively reprocessed by injection molding. The experimental results show that, after the first mechanical recycling and reprocessing cycle, the thermal, rheological, mechanical, and electrical properties for the recycled and virgin HDPE/MWCNT composites with 0.1–3 wt.% were rather similar within the experimental error of the measurements. In contrast, the recycled HDPE/MWCNT composites with 5 wt.% showed a reduction in viscosity, mechanical and electrical properties with recycling. After four recycling and reprocessing cycles, degradation in the Young modulus (−35%), tensile strength (−25%), elongation at break (−60%) and electrical conductivity (−2 orders of magnitude) of the HDPE/MWCNT composite with 5 wt.% was observed as compared with the virgin composite.

From an industrial perspective, it is feasible to recycle HDPE/MWCNT composite waste by mechanical recycling and use it to manufacture products with favorable mechanical properties, covering insulating, antistatic and semiconducting ranges depending on the MWCNT loading, owing to the protective effect of carbon nanotubes against thermomechanical degradation.
Multi-Robotic Disassembly Line Balancing Using Deep Reinforcement Learning
Authors: Mei Kai , Fang Yilin
Published: August 2021

With the continuous development of society, the speed of product upgrades is getting faster and faster, and the recycling of EOL products has great benefits to environmental protection and resource utilization. In recent years, with the rapid development of artificial intelligence (AI), more and more scholars have begun to apply reinforcement learning (RL) and deep learning (DL) to solve practical problems. This paper focuses on the application of deep reinforcement learning (DRL) in the multi-robotic disassembly line balance problem (MRDLBP). In the MRDLBP problem, for each workstation, the cycle time (CT) is determined, and the robot resources that can be accommodated are optional. Multi-objective includes minimizing workstation idle time, priority disassembly of high-demand components and minimizing energy consumption. The input model is single, and robotic resources are variable. Firstly, we formulated the mathematical model of the problem and proposed a framework for MRDLBP using DRL. In addition, we modeled the DRL system with three DRL algorithms, including deep Q network (DQN), double DQN (D_DQN) and prioritized experience replay DQN (PRDQN), to solve the problem. Finally, we build different test cases by adjusting the type of input model and the number of robot resources to test the performance of the three algorithms under different complexity conditions.
4D Printing of Complex Ceramic Structures via Controlling Zirconia Contents and Patterns
Authors: Rong Zhicheng , Liu Chang , Hu Yingbin
Published: August 2021

In recent years, more and more attentions have been attracted on integrating three-dimensional (3D) printing with fields (such as magnetic field) or innovating new methods to reap the full potential of 3D printing in manufacturing high-quality parts and processing nano-scaled composites. Among all of newly innovated methods, four-dimensional (4D) printing has been proved to be an effective way of creating dynamic components from simple structures. Common feeding materials in 4D printing include shape memory hydrogels, shape memory polymers, and shape memory alloys. However, few attempts have been made on 4D printing of ceramic materials to shape ceramics into intricate structures, owing to ceramics’ inherent brittleness nature. Facing this problem, this investigation aims at filling the gap between 4D printing and fabrication of complex ceramic structures. Inspired by swelling-and-shrinking-induced self-folding, a 4D printing method is innovated to add an additional shape change of ceramic structures by controlling ZrO2 contents and patterns. Experimental results evidenced that by deliberately controlling ZrO2 contents and patterns, 3D-printed ceramic parts would undergo bending and twisting during the sintering process. To demonstrate the capabilities of this method, more complex structures (such as a flower-like structure) were fabricated. In addition, functional parts with magnetic behaviors were 4D-printed by incorporating iron into the PDMS-ZrO2 ink.
Collaborative Robot Risk of Passage Among Dynamic Obstacles
Authors: Flowers Jared T. , Wiens Gloria J.
Published: August 2021

Industry 4.0 projects ubiquitous collaborative robots in smart factories of the future, particularly in assembly and material handling. To ensure efficient and safe human-robot collaborative interactions, this paper presents a novel algorithm for estimating Risk of Passage (ROP) a robot incurs by passing between dynamic obstacles (humans, moving equipment, etc.). This paper posits that robot trajectory durations will be shorter and safer if the robot can react proactively to predicted collision between a robot and human worker before it occurs, compared to reacting when it is imminent. I.e., if the risk that obstacles may prohibit robot passage at a future time in the robot’s trajectory is greater than a user defined risk limit, then an Obstacle Pair Volume (OPV), encompassing the obstacles at that time, is added to the planning scene. Results found from simulation show that an ROP algorithm can be trained in ∼120 workcell cycles. Further, it is demonstrated that when a trained ROP algorithm introduces an OPV, trajectory durations are shorter compared to those avoiding obstacles without the introduction of an OPV. The use of ROP estimation with addition of OPV allows workcells to operate proactively smoother with shorter cycle times in the presence of unforeseen obstacles.
A Cloud Solution for Service Oriented Workshop Management
Authors: Li Xiaobin , Yin Chao
Published: August 2021

Cloud manufacturing is a state-of-art networked manufacturing model with the idea and technologies of cloud computing to transform traditional production-oriented manufacturing into service-oriented manufacturing. This emerging model can make manufacturing resources, in a manner similar to traditional utilities such as water, gas and electricity, available (offered) over the internet as convenient, scalable, on-demand services to enterprises. The aim is to improve the sharing efficiency of manufacturing resources and reduce manufacturing costs in industries. In this paper, the current research of cloud manufacturing is summarized, including relevant theories, technologies and applications. A cloud solution for workshop management is proposed from a service perspective, along with its architecture and business process. The methodologies, including manufacturing resource virtualization and workshop sensor network configuration are developed to support heterogeneous data integration and effective collaboration among services in cloud. A case study is demonstrated and discussed to validate the proposed cloud service system.
Closed-Loop Control of Silicone Extrusion-Based Additive Manufacturing Based on Machine Vision
Authors: Tian Xiaoqing , Li Yaling , Ma Dingyifei , Han Jiang , Xia Lian
Published: August 2021

In this paper, the control of strand width uniformity in extrusion-based additive manufacturing process based on machine vision is studied. Firstly, the images of the strand width are collected frame by frame by a CCD camera. Secondly, through a series of processes of images acquisition, images processing including images filtering, images binarization and information extraction, the useful information of strand width is obtained. Then, the theoretical relationship between the strand width and printing speed is obtained through experimental research, and a control model is obtained. Finally, by using the control model and the strand width obtained from images processing, the printing speed is adjusted to an appropriate value, which eventually led to the stabilization of the strand width. The uncontrolled and logarithmic controlled, are studied in this work. The results show that the logarithmic controlled strand width is more stable than the uncontrolled strand width. Therefore, the instability of strand width in material extrusion-based additive manufacturing process can be effectively solved by machine vision control.
Performance Evaluation of Robot Polishing in Macro-Micro System Based Polishing Robot
Authors: Koto Katsuki , Tsukada Takuhiro , Ogawa Shotaro , Kakinuma Yasuhiro
Published: August 2021

Polishing is an important process performed in the finishing and repair processes of mechanical parts and is still a manual work of skilled workers. However, in addition to the time and cost required for manual polishing, there are also problems such as a decrease in the number of workers and health hazards due to dust generated during polishing. From these problems, the demand for automatic polishing is increasing at manufacturing sites. To automate polishing process, a macro-micro system based polishing robot which consists of a functional end-effector and industrial robot has been proposed. Regarding end effectors, mechanical design aiming for high rigidity and motion control methods for keeping the contact force constant is being researched. Meanwhile, the tool rotation speed of the spindle is independently controlled typically. Therefore, in this research, a functional polishing module capable of polishing force control and tool rotation control according to the tool feed rate is developed as the end effector. For the polishing automation, the macro-micro system based polishing robot is constructed attaching the polishing module to the industrial robot. From the viewpoint of Preston’s law, the effectiveness of the robot polishing is investigated through polishing experiments and measuring the shape of the polished surface.
Advanced Modeling of Drilling – Realistic Process Mechanics Leading to Helical Chip Formation
Authors: Lortz Wolfgang , Pavel Radu
Published: August 2021

There is considerable interest in the “Industry 4.0 project”. Industry hopes that a general solution of the metal removal problem will be found through the use of highly automated manufacturing data. Scientists hope that the computer will provide better models based on artificial intelligence and machine learning. Initial attempts leveraging existing models did not result in satisfactory results yet — largely because of mathematical, physical and metallurgical reasons. This paper presents a new mathematical-physical model to describe the total process mechanics from volume conservation, to friction, to metal plasticity with self-hardening or softening effects and dynamic phenomena during metal plastic flow. The softening effects are created by high energy corresponding to high strain-rate resulting in high temperatures. Furthermore, the developed equations for strain-rate discontinuities as well as yield shear stress with body forces have an interdependent relationship and lead to plastic deformation with dynamic behavior in the total chip formation zone. This plastic deformation is the only parameter that will not disappear after completing the process. This leads to the opportunity to check the theoretically developed grid deformation and compare it with practical results of the same area. In this publication this new theory will be used to analyze the complex contact and friction conditions between the chip and tool edge of a twist drill during operation. It will be shown that the existing conditions are leading to high wear at the corner edge and flank wear at the tool cutting edge. In addition, the existing temperatures can be estimated and compared with practical measurements, and all these complex and difficult conditions create a helical spiral chip, which could be developed as it will be presented in this paper.
Characterizing the Conductivity of Aerosol Jet Printed Silver Features on Glass
Authors: Ratnayake Dilan , Curry Alexander Thomas , Qu Chuang , Usher John , Walsh Kevin
Published: August 2021

Aerosol Jet Printing shows a lot of promise for the future of printable electronics. It is compatible with a wide range of materials and can be printed on nearly any type of surface features because of its 3–5 mm standoff distance from the substrate. However, nearly all materials printed require some form of post-sintering processing to reduce the electrical resistance. Many companies develop these materials, but only provide a narrow range of post processing results to demonstrate the achievable conductivity values. In this paper, a design of experiment (DOE) is presented that demonstrates a way to characterize any material for Aerosol Jet Printing during and after post sintering processing by measuring conductivity with different time and temperature values. From these results, a linear regression model can be made to develop an equation that predicts conductivity at a given time-temperature value. This paper applies this method to Clariant Ag ink and sinters silver pads in an oven. A linear regression model is successfully developed that fits the data very well. From this model, an equation is derived to predict the conductivity of the Clariant Ag ink for any time-temperature value. Although only demonstrated with an oven and one type of ink, this method of experimentation and model development can be done with any material and any post processing method.
Conical Thermoplastic Composite Anisogrid Lattice Structure by Innovative Out-of-Autoclave Molding Process
Authors: Quadrini Fabrizio , Santoro Daniele , Iorio Leandro , Santo Loredana
Published: August 2021

A new manufacturing process for thermoplastic (TP) composite parts has been used to produce conical anisogrid composite lattice structure (ACLS). An out-of-autoclave (OOA) process has been prototyped by using the compaction exerted by a heat-shrink tube after its exposition to heat in oven. Narrow thermoplastic prepreg tapes have been wounded on a metallic conical patterned mold at room temperature; then, the conical structure has been inserted in the heat-shrink tube and heated. TP unidirectional prepreg tapes have been used with polypropylene matrix and glass fibers. After molding, the TP ACLS has been tested under axial and transverse compression. Conical adapters were used in the transverse loading condition to allow uniform application of the load. Density measurement has been also performed to assess the quality of the OOA process. Results of this study show that TP ACLS with complex shape may be produced with OOA solutions without affecting mechanical performance. In fact, porosity levels of the consolidate ACLS are comparable with the initial prepreg despite of the absence of vacuum during molding. Moreover, high compressive stiffness was measured along both directions without observing damages, buckling or cracks in multiple tests. In the future, this kind of technology could be used for larger ACLSs by substituting the heat-shrink tube with a narrow tape to be wound as well after lamination.
A Computational Study on Novel Runner Extension Designs via 3D Sand-Printing to Improve Casting Performance
Authors: Stebbins Ryan , King Philip , Manogharan Guha
Published: August 2021

3D sand-printing (3DSP) has become more popular in foundry applications due to its ability to create complex gating geometries. Since filling related defects, like entrained air and bi-films, are most commonly caused by high melt velocity and turbulence, recent 3DSP research has focused on designing gating systems to reduce melt velocity and turbulence. However, there have been no reported efforts on advancements in the design of runner extensions as a method to improve casting quality, despite its tremendous impact on the initial metal flow characteristics. The ability to fabricate 3DSP molds allow for unique runner extension designs that aid in improving casting quality. This paper is the first study known to the authors that investigates novel 3D runner extension designs to determine the most effective design for reducing sand casting defects. Based on literature review and design principles developed for 3D sprue geometries, six different runner extensions were studied using Computational Fluid Dynamics (CFD) modeling for foundry pouring conditions. The designs were evaluated on their ability to reduce defects like entrained air and bubbles, as well as to prevent backflow and reflected waves. An unweighted ranking matrix and comparison matrix against the control (straight runner extension) has been established based on air entrainment, tracer, voids, and extension volume. The results showed that the by-pass principal and surge control systems are effective at reducing reflective waves and controlling the ingate flow. The novel 3D duckbill trap extension proposed in this study had the best overall performance based on a 16% reduction in entrained air and a 71% reduction in void particles in the casting volume compared to the control extension design. These results provide a framework to further optimize runner extensions, utilize the advantages of 3D Sand-Printing technology to improve mechanical strength and reduce filling defects in sand-casting.
Development of Intertwined Infills to Improve Multi-Material Interfacial Bond Strength
Authors: Mustafa Irfan , Kwok Tsz-Ho
Published: August 2021

Recently the availability of various materials and ongoing research in developing advanced systems for multi-material additive manufacturing (MMAM) have opened doors for innovation in functional products. One major concern of MMAM is the strength at the interface between materials. This paper hypothesizes overlapping and interlacing materials to enhance the bonding strength. To test this hypothesis, we need a computer-aided manufacturing (CAM) tool that can process the overlapped material regions. However, existing computational tools lack key multi-material design processing features and have certain limitations in making full use of the material information, which restricts the testing of our hypothesis. Therefore, this research also develops a new MMAM slicing framework that efficiently identifies the boundaries for materials to develop different advanced features. By modifying a ray tracing technology, we develop layered depth material images (LDMI) to process the material information from computer-aided design (CAD) models for slicing and process planning. Each sample point in the LDMI has associated material and geometric properties that are used to identify the multi-material regions. Based on the material information in each slice, interlocking joint (T-Joint) and interlacing infill are generated in the regions with multiple materials. Tensile tests have been performed to verify the enhancement of mechanical properties by the use of overlapping and interlacing materials.
Study of Formability Limit Based on Ductile Damage Criteria of Incremental Sheet Forming of Titanium Grade 2 Sheet
Authors: Pal Mainak , Pandya Vandit , Agrawal Anupam
Published: August 2021

Incremental sheet forming (ISF) process is an alternative and advanced sheet metal forming technique, well-known due to its flexible and die-less method of forming compared to other traditional forming methods. It is a modern concept-based sheet forming technique adaptive to develop both simple and complicated shapes/components successfully. The clamped metal sheet undergoes small incremental deformations via layer by layer line movement of ball point type hemispherical tool with the help of numerically controlled (NC) user pre-defined definite toolpath. Numerical simulation is an effective method to study the forming process and predict the formability limit in ISF. In this paper, ductile damage failure criteria has been used to investigate the forming limit diagram (FLD) of commercially pure Titanium grade 2 (CP-Ti Gr2) sheet through finite element simulation in ABAQUS® software. Truncated conical shape geometry with three different incremental step depth (Δz) at constant wall angle has been formed. Simulation results of the FLD have been validated and compared with the experimental data from the literature. Finite element analysis (FEA) for predicting the sheet thickness variation along the forming depth and process forming forces also have been carried out. Higher step depth resulted in better formability of the titanium sheet with less sheet thickness reduction. Forming forces (Fz) with smaller step depth showed good results as compared to other two step depths.
Simulation and Characterization of Nanoparticle Thermal Conductivity for a Microscale Selective Laser Sintering System
Authors: Grose Joshua , Dibua Obehi G. , Behera Dipankar , Foong Chee S. , Cullinan Michael
Published: August 2021

Additive Manufacturing (AM) technologies are often restricted by the minimum feature size of parts they can repeatably build. The microscale selective laser sintering (μ-SLS) process, which is capable of producing single micron resolution parts, addresses this issue directly. However, the unwanted dissipation of heat within the powder bed of a μ-SLS device during laser sintering is a primary source of error that limits the minimum feature size of the producible parts. A particle scale thermal model is needed to characterize the thermal properties of the nanoparticles undergoing sintering and allow for the prediction of heat affected zones (HAZ) and the improvement of final part quality. Thus, this paper presents a method for the determination of the effective thermal conductivity of metal nanoparticle beds in a microscale selective laser sintering process using finite element simulations in ANSYS. CAD models of nanoparticle groups at various timesteps during sintering are developed from Phase Field Modeling (PFM) output data, and steady state thermal simulations are performed on each group. The complete simulation framework developed in this work is adaptable to particle groups of variable sizes and geometric arrangements. Results from the thermal models are used to estimate the thermal conductivity of the copper nanoparticles as a function of sintering duration.
Two-Dimensional Image Based Product Connector Recognition for Robotic Disassembly in Remanufacturing
Authors: Hu Yang , Wang Yalin , Xu Feng , Yao Bitao , Xu Wenjun , Feng Hao
Published: August 2021

Remanufacturing has received increasing attention for environmental protection and resource conservation considerations. Disassembly is a crucial step in remanufacturing, is always done manually which is inefficient while robotic disassembly can improve the efficiency of the disassembly. Aiming at the problem of product connector recognition during the robotic disassembly process, we analyze the template matching and feature matching principles based on two-dimensional images. To reduce the computational complexity of traditional template matching, a stepwise search strategy combining coarse and fine is proposed. Based on this a product connector recognition algorithm based on fast template matching and a product connector recognition algorithm based on feature matching is designed. Taking bolts and hexagon nuts as examples, the recognition effects of the two algorithms are compared and analyzed.
Knowledge Recommendation System for Human-Robot Collaborative Disassembly Using Knowledge Graph
Authors: Hu Yang , Ding Yiwen , Xu Feng , Liu Jiayi , Xu Wenjun , Feng Hao
Published: August 2021

In recent years, more and more attention has been paid to Human-Robot Collaborative Disassembly (HRCD) in the field of industrial remanufacturing. Compared with the traditional manufacturing, HRCD helps to improve the manufacturing flexibility with considering the manufacturing efficiency. In HRCD, knowledge could be obtained from the disassembly process and then provides useful information for the operator and robots to execute their disassembly tasks. Afterwards, a crucial point is to establish a knowledge-based system to facilitate the interaction between human operators and industrial robots. In this context, a knowledge recommendation system based on knowledge graph is proposed to effectively support Human-Robot Collaboration (HRC) in disassembly. A disassembly knowledge graph is constructed to organize and manage the knowledge in the process of HRCD. After that, based on this, a knowledge recommendation procedure is proposed to recommend disassembly knowledge for the operator. Finally, the case study demonstrates that the developed system can effectively acquire, manage and visualize the related knowledge of HRCD, and then assist the human operator to complete the disassembly task by knowledge recommendation, thus improving the efficiency of collaborative disassembly. This system could be used in the human-robot collaboration disassembly process for the operators to provide convenient knowledge recommendation service.
Comparison of the effects of adenosine, isoproterenol and their combinations on pulmonary transit time in rats using contrast echocardiography
Authors: Su Feng , Shi Yun-Yan , Wang Bo , Zheng Xiao-Zhi
Published: August 2021

Aims: To compare the effects of adenosine (Ade), isoproterenol (Iso) and their combinations on pulmonary transit time (PTT) in rats using contrast echocardiography.Material and methods: Thirty-two adult Sprague Dawley (SD) rats were divided into four groups (n=8) according the medicines of tail-intravenous injection: Group 1, control; Group 2, Ade; Group 3, Iso; Group 4, Ade+Iso. They all underwent conventional echocardiography and contrast echocardiography with measurements of PTT.Results: With Ade injection, OnsetRV-OnsetLV PTT (PTT1), PeakRV-PeakLV PTT (PTT2) and OnsetRV-PeakLV PPT (PTT3) decreased and PTT3 had the largest decreased percentage, with the highest performance in differentiating the Ade group from the control group [the area under receiver operating characteristic curve (AUC), sensitivity and Youden’s index was maximal]. With Iso injection, PTT1, PTT2 and PTT1 all increased and PTT1 had the largest increased percentage, with the highest performance in differentiating the Iso group from the control group (AUC, sensitivity and Youden’s index was maximal). With a combination injection of Ade and Iso, the PTT values were similar to the control group and no PTT coulddifferentiate the Ade+Iso group from the control group.Conclusions: Ade or/and Iso exerted distinct effects on PTT. These findings remind us that it is a necessary to consider the effects of medicine (especially cardiopulmonary vasoactive drugs) on the PTT values. At the same time, it provides the basis for the clinical transformation of consecutive Iso/Ade treatment from the perspective of pulmonary circulation.
The role of lung ultrasonography in predicting the clinical outcome of complicated community-acquired pneumonia in hospitalized children
Authors: Ionescu Marcela Daniela , Balgradean Mihaela , Filip Cristina , Taras Roxana , Capitanescu Georgiana Mihaela , Berghea Florian , Berghea Camelia Elena , Cirstoveanu Catalin Gabriel
Published: August 2021

Aims: This study’s objective was to analyze lung ultrasonography (LUS) characteristics in hospitalized pediatric patients with complicated community-acquired pneumonia (CAP). We hypothesized that LUS could be correlated with the clinical outcome in these cases.Materials and methods: In this retrospective study, we evaluated the LUS appearances (at admission and five days after the beginning of the treatment) and the progression of complicated CAP.Results: We identified 45 patients who fulfilled the inclusion criteria. Several complications occurred in these subjects during follow-up including: serofibrinous pleurisy (62.2%), empyema (15.6%), encapsulated pleurisy (11.1%), lung abscess (6.7%) and necrotizing pneumonia (2.2%). In addition, 22.2% of the patients required surgical treatment: draining tube (11.1%), decortication (6.7%) and resection (4.4%). Intensive care unit admission was needed in 8.9% of patients. The median duration of hospitalization was 14 [9.7; 19.7] days. The thickness of pleural effusion with a cut-off value of 10 mm seen by LUS was a predictor for the need for continuous thoracic drainage (p<0.01), segmentectomy or thoracoscopic surgery (p=0.03) and prolonged hospitalization over 10 days (p<0.01). Hyperechogenic pleural effusion, presence of septa and fluid bronchogram on 1st LUS evaluation were independent predictors of segmentectomy or thoracoscopic decortication (p<0.01) and of longer hospitalization (p=0.02, p<0.01, p<0.01 respectively).Conclusions: The ultrasound characteristics of complicated CAP can offer valuable information to predict the clinical evolution of CAP and so can help the development of personalized medical management plans in these patients.
Role of electron and ion irradiation in a reliable lift-off process with electron beam evaporation and a bilayer PMMA resist system
Authors: Sun Bin , Grap Thomas , Frahm Thorben , Scholz Stefan , Knoch Joachim
Published: August 2021

This paper addresses issues related to cracking and blisters in deposited films encountered in a lift-off process with electron beam evaporation and a bilayer PMMA resist system. The impact of charged particles, i.e., electrons and ions, is investigated using an electron beam evaporation chamber equipped with ring-magnets and a plate electrode placed in front of the sample. By replacing the plate electrode with a hollow metallic cylinder, the modified evaporation setup utilizing passive components allows complete elimination of resist shrinkage and bubble formation yielding near perfect deposition results for a large variety of different materials.
Highly selective GaAs/AlGaAs dry etching using HBr/SF6/He
Authors: Barrow Michael , Wright Shawn , Puzycki Sarah , Shah Piyush , Bedford Robert , Zhang Yuanchang , Phillips Jamie
Published: August 2021

Selective etching of GaAs is critical for many applications, including flat optical components and high electron mobility transistors. It is long-known that F-containing process gases produce a nonvolatile AlFx layer on AlGaAs. In this work, we present a selective GaAs etch using an inductively coupled plasma with an HBr/SF6/He etch chemistry. The optimized process exhibits >1μm/min etch rates, >200:1 GaAs:AlGaAs selectivity, >50:1 GaAs:photoresist selectivity, sub-nm surface roughness, and minimal undercut. The effect of aspect ratio is investigated, revealing limitations for deposition of an Si-rich passivation layer. Moreover, selectivity dramatically increases with an AlGaAs etch stop with high (90%) Al content. By characterizing an HBr-based selective GaAs etch, this work provides a possible alternative to the better established chlorine-based selective processes.
An Intentionally Designed Walking Program for Seniors Results in Enhanced Community Connection
Authors: Walters Kellie , Marshall Mary , Wilkinson Alexandra Nicole , Natividad Michael Duxx
Published: August 2021

Social connection is vital for older adults’ physical and psychological well-being, yet nearly one third of them report feeling lonely. The purpose of this study was to evaluate the influence of a monthly walking program (walking once a month for 8 months) on older adults’ community connection. Older adults (Mage = 78.06 ± 5.98 years) completed a focus group at the completion of the program (n = 15). Qualitative findings indicate that participation in the walking program led to enhanced social connection. Researchers developed six major themes: (1) frequent and engaging walking programs, (2) benefits of group activity, (3) enhanced social connections, (4) connection to the community, (5) knowledge about transit, and (6) personal well-being, and 10 subthemes. Implications from this study highlight the importance of designing a walking program with older adults’ needs and desires in mind.
Pragmatic Evaluation of Older Adults’ Physical Activity in Scale-Up Studies: Is the Single-Item Measure a Reasonable Option?
Authors: Macdonald Heather M. , Nettlefold Lindsay , Bauman Adrian , Sims-Gould Joanie , McKay Heather A.
Published: August 2021

Convergent validity and responsiveness to change of the single-item physical activity measure were assessed in adults aged 60 years and older, at baseline (n = 205) and 6 months (n = 177) of a health promotion program, Choose to Move. Spearman correlations were used to examine associations between physical activity as measured by the single-item measure and the Community Health Activities Model Program for Seniors (CHAMPS) questionnaire at baseline and for 6-month change in all participants and for sex and age (60–74 years, and ≥75 years) subgroups. Effect size assessed responsiveness to change in physical activity for both tools. Baseline physical activity by the single-item measure correlated moderately with physical activity by the CHAMPS questionnaire in all participants and subgroups. Correlations were weaker for change in physical activity. Effect size for physical activity change was larger for the single-item measure than for the CHAMPS questionnaire. The single-item measure is a valid, pragmatic tool for use in intervention and scale-up studies with older adults.
Impact of a Novel Training Approach on Hemodynamic and Vascular Profiles in Older Adults
Authors: Woessner Mary N. , Welsch Michael A. , VanBruggen Mitch D. , Johannsen Neil M. , Credeur Daniel P. , Pieper Carl F. , Sloane Richard , Earnest Conrad P. , Ortiz De Zevallos Munoz Joaquin , Church Timothy S. , Ravussin Eric , Kraus William E. , Allen Jason D.
Published: August 2021

Exercise training beneficially moderates the effects of vascular aging. This study compared the efficacy of Peripheral Remodeling through Intermittent Muscular Exercise (PRIME), a novel training regimen, versus aerobic training on hemodynamic profiles in participants ≥70 years at risk for losing functional independence. Seventy-five participants (52 females, age: 76 ± 5 years) were assessed for hemodynamic and vascular function at baseline, after 4 weeks of either PRIME or aerobic training (Phase 1) and again after a further 8 weeks of aerobic and resistance training (Phase 2). Data were analyzed using 2 × 2 repeated-measures analysis of variance models on the change in each dependent variable. PRIME demonstrated reductions in brachial and aortic mean arterial pressure and diastolic blood pressure (p < .05) from baseline after Phase 1, which were sustained throughout Phase 2. Earlier and greater reductions in blood pressure following PRIME support the proposal that peripheral muscular training could beneficial for older individuals commencing an exercise program.
Enactments of Integrated, Disability-Inclusive Sport Policy by Sporting Organizations
Authors: Hammond Andrew M. , Bundon Andrea , Pentifallo Gadd Caitlin , Konoval Tim
Published: August 2021

This article critically analyzed the enactment of disability-inclusive sport policies by provincial sporting organizations in British Columbia. Thirty semistructured interviews with managers representing 13 organizations informed the analysis. Findings highlighted how organizational circumstances prompted managers to enact integration policies in novel ways at the regional level. For instance, nondisabled sporting organizations mediated the adoption of integration policies due to the perceived impact on nondisabled programming. In contrast, disability sport organizations resisted integration out of concern that nondisabled organizations could not deliver programming to an equivalent standard. To thwart the perceived integration threat, disability sport organizations developed novel solutions, such as registering themselves as freestanding organizations. Discussion arises as to whether integration is the “gold standard” of inclusion in disability sport. Policy recommendations are also discussed.
Repurposing RNA sequencing for discovery of RNA modifications in clinical cohorts
Authors: Tan Kar-Tong , Ding Ling-Wen , Wu Chan-Shuo , Tenen Daniel G. , Yang Henry
Published: August 2021

Reusing RNA sequencing data from clinical cohorts reveals relationships between the epitranscriptome and clinical outcomes.
The exon-junction complex helicase eIF4A3 controls cell fate via coordinated regulation of ribosome biogenesis and translational output
Authors: Kanellis Dimitris C. , Espinoza Jaime A. , Zisi Asimina , Sakkas Elpidoforos , Bartkova Jirina , Katsori Anna-Maria , Boström Johan , Dyrskjøt Lars , Broholm Helle , Altun Mikael , Elsässer Simon J. , Lindström Mikael S. , Bartek Jiri
Published: August 2021

The exon junction complex helicase eIF4A3 orchestrates Pol I and Pol II posttranscriptional events.
The physics of cement cohesion
Authors: Goyal Abhay , Palaia Ivan , Ioannidou Katerina , Ulm Franz-Josef , van Damme Henri , Pellenq Roland J.-M. , Trizac Emmanuel , Del Gado Emanuela
Published: August 2021

Ion-water restructuring under confinement is at the origin of ion-specific nanoscale forces that control cement cohesion.
The source scaling and seismic productivity of slow slip transients
Authors: Passarelli Luigi , Selvadurai Paul Antony , Rivalta Eleonora , Jónsson Sigurjón
Published: August 2021

Aseismic and seismic slip scaling indicate similar physics governing tremor and earthquake swarms during slow slip events.
Efficient energy transport in an organic semiconductor mediated by transient exciton delocalization
Authors: Sneyd Alexander J. , Fukui Tomoya , Paleček David , Prodhan Suryoday , Wagner Isabella , Zhang Yifan , Sung Jooyoung , Collins Sean M. , Slater Thomas J. A. , Andaji-Garmaroudi Zahra , MacFarlane Liam R. , Garcia-Hernandez J. Diego , Wang Linjun , Whittell George R. , Hodgkiss Justin M. , Chen Kai , Beljonne David , Manners Ian , Friend Richard H. , Rao Akshay
Published: August 2021

Precisely tuning an organic semiconductor’s crystalline order allows exciton transport to proceed 2-3 orders of magnitude faster.
Bacteriophage Treatment before Chemical Disinfection Can Enhance Removal of Plastic-Surface-Associated Pseudomonas aeruginosa
Authors: Stachler Elyse , Kull Anina , Julian Timothy R.
Published: August 2021

Phages are already utilized in the health care industry to treat antibiotic-resistant infections, such as those on implant-associated biofilms and in compassionate-care cases. Phage treatment could also be a promising new tool to control pathogens in the built environment, preventing infections from occurring.
Elevated Rates of Indeterminate Results on QuantiFERON-TB Gold Plus in COVID-19 Patients
Authors: Shier Kileen L.
Published: August 2021

Interferon gamma release assays are used to screen various patient populations for latent tuberculosis infection. In this issue of the
Journal of Clinical Microbiology
, Ward et al. (J Clin Microbiol 59:e00811-21, 2021,
https://doi.org/10.1128/JCM.00811-21
) investigated an increased indeterminate rate in the QuantiFERON-TB Gold Plus assay among COVID-19 patients that was independent of immunosuppressive agents and lymphopenia.
Human Cytomegalovirus RNA2.7 Is Required for Upregulating Multiple Cellular Genes To Promote Cell Motility and Viral Spread Late in Lytic Infection
Authors: Lau Betty , Kerr Karen , Camiolo Salvatore , Nightingale Katie , Gu Quan , Antrobus Robin , Suárez Nicolás M. , Loney Colin , Stanton Richard J. , Weekes Michael P. , Davison Andrew J.
Published: August 2021

In addition to messenger RNAs (mRNAs), the human genome encodes a large number of long noncoding RNAs (lncRNAs). Many lncRNAs that have been studied in detail are associated with broad modulation of gene expression and have important biological roles.
T Cell-Intrinsic Interferon Regulatory Factor 1 Expression Suppresses Differentiation of CD4+T Cell Populations That Support Chronic Gammaherpesvirus Infection
Authors: Jondle C. N. , Johnson K. E. , Mboko W. P. , Tarakanova V. L.
Published: August 2021

Gammaherpesviruses infect over 95% of the adult population, last the lifetime of the host, and are associated with multiple cancers. These viruses usurp the germinal center response to establish lifelong infection in memory B cells.