bluuebunny/crossref_metadata_2025 huggingface dataset:
Blood-based magnetohydrodynamic Casson hybrid nanofluid flow on convectively heated bi-directional porous stretching sheet with variable porosity and slip constraints
Authors: Lone Showkat Ahmad , Bossly Rawan , Alduais Fuad S. , Al-Bossly Afrah , Khan Arshad , Saeed Anwar
Published: October 2024

Fluid flow through porous spaces with variable porosity has wide-range applications, notably in biomedical and thermal engineering, where it plays a vital role in comprehending blood flow dynamics within cardiovascular systems, heat transfer and thermal management systems improve efficiency using porous materials with variable porosity. Keeping these important applications in view, in current study blood-based hybrid nanofluid flow has considered on a convectively heated sheet. The sheet exhibits the properties of a porous medium with variable porosity and extends in both the x and y directions. Blood has used as base fluid in which the nanoparticles of Cu and CuO have been mixed. Thermal radiation, space-dependent, and thermal-dependent heat sources have been incorporated into the energy equation, while magnetic effects have been integrated into the momentum equations. Dimensionless variables have employed to transform the modeled equations into dimensionless form and facilitating their solution using bvp4c approach. It has concluded in this study that, both the primary and secondary velocities augmented with upsurge in variable porous factor and declined with escalation in stretching ratio, Casson, magnetic, and slip factors along x- and y-axes. Thermal distribution has grown up with upsurge in Casson factor, magnetic factor, thermal Biot number, and thermal/space-dependent heat sources while has retarded with growth in variable porous and stretching ratio factors. The findings of this investigation have been compared with the existing literature, revealing a strong agreement among present and established results that ensured the validation of the model and method used in this work.
Quantum color image encryption: Dual scrambling scheme based on DNA codec and quantum Arnold transform
Authors: Cheng 程 Tao 涛 , Zhao 赵 Run-Sheng 润盛 , Wang 王 Shuang 爽 , Wang 王 Kehan 柯涵 , Ma 马 Hong-Yang 鸿洋
Published: October 2024

In the field of Internet, an image is of great significance to information transmission. Meanwhile, how to ensure and improve its security has become the focus of international research. We combine DNA codec with quantum Arnold transform (QArT) to propose a new double encryption algorithm for quantum color images to improve the security and robustness of image encryption. First, we utilize the biological characteristics of DNA codecs to perform encoding and decoding operations on pixel color information in quantum color images, and achieve pixel-level diffusion. Second, we use QArT to scramble the position information of quantum images and use the operated image as the key matrix for quantum XOR operations. All quantum operations in this paper are reversible, so the decryption operation of the ciphertext image can be realized by the reverse operation of the encryption process. We conduct simulation experiments on encryption and decryption using three color images of “Monkey”, “Flower”, and “House”. The experimental results show that the peak value and correlation of the encrypted images on the histogram have good similarity, and the average normalized pixel change rate (NPCR) of RGB three-channel is 99.61%, the average uniform average change intensity (UACI) is 33.41%, and the average information entropy is about 7.9992. In addition, the robustness of the proposed algorithm is verified by the simulation of noise interference in the actual scenario.
Toroidal injection angle dependence of EC assisted plasma initiation at DIII-D
Authors: Yang J. , Sips A.C.C. , de Vries P. , Sinha J. , Kim H.T. , Glass F. , Austin M. , van Zeeland M. , Herfindal J.L. , Shafer M. , Nelson A.O. , Marini C. , Yoo M.G.
Published: October 2024

An experimental scan of the electron cyclotron waves (EC) toroidal injection angle in plasma breakdown is performed at the DIII-D tokamak. The second harmonic, extraordinary mode EC is used for the study. The dependence of n
e and T
e on the EC injection angle cannot be conclusively drawn from this study due to the large error bars in the n
e and T
e measurements. On the other hand, high T
e data points are observed in some discharges which can be explained by nonlinear heating. The D

α
emission measurement shows a clear relation between the breakdown time and the injection angle. An experimental investigation of the cause of the dependence of breakdown delay on the EC injection angle suggests that when the injection angle is oblique, the EC heating after the reflection at the inboard wall may become ineffective and cause the breakdown delay even when the EC heating before and directly upon injection remains effective. A preliminary run of the heat and transport balance code DYON indicates that the obtained dataset is suitable for a quantitative validation of EC absorption models.
An Immersive VR Training Scenario for Safe Methanol Bunkering in the Maritime Industry
Authors: Liu Yisi , Chee Onn Tham , Lim Eric , Chua Rick , Arif Bin Ari Tantawi Muhammad , Ying Hui Ngiam
Published: October 2024

The maritime industry, pivotal in global commerce, faces critical challenges in mitigating environmental impacts, especially greenhouse gas emissions. The International Maritime Organization (IMO) targets a substantial reduction in emissions by 2050, necessitating innovative approaches to fuel usage. Methanol, recognized for its lower carbon intensity, emerges as a viable alternative fuel. However, its flammability and toxicity introduce complex safety and operational demands. To address these challenges, we have developed a state-of-the-art Virtual Reality (VR) training program specifically for methanol bunkering operations. This training, utilizing Unity 3D and Meta Quest 2, offers a highly interactive and realistic experience. Trainees engage in a comprehensive simulation that covers the entire bunkering process, including safety checks, equipment handling, and emergency response protocols. The VR environment allows for dynamic adjustments by trainers, enhancing the realism and educational value of the scenario. Our program also includes an assessment component that evaluates the trainee’s performance across various metrics such as safety protocol adherence, decision-making, and situational awareness. The anticipated outcome of this VR training initiative is to significantly improve the preparedness of maritime personnel in handling alternative fuels, thereby supporting the industry’s transition towards sustainable practices and contributing to broader environmental protection goals.
CFD studies into frictional effects of ship coatings to enhance condition monitoring & increase efficiency
Authors: Xu Haihua , Ramganesh T , Chen Haoliang , Eng Tan Ching
Published: October 2024

Managing biofouling on ship hulls is essential for reducing CO2 emissions in the shipping industry. Biofouling, characterized by the accumulation of organisms on hulls, escalates surface roughness and hydrodynamic drag, subsequently increasing fuel consumption and CO2 emissions. In response, AkzoNobel, Royal Philips, and Damen Shipyards are developing a fouling prevention technology that utilizes Ultra Violet Light Emitting Diodes (UV-LEDs). The use of an array of multiple UV-LED tiles may lead to non-uniformities from gaps between tiles, potentially increasing frictional resistance due to variations in thickness and surface roughness at the tile joints. This study examines the impact of these non-uniformities on skin friction through simulations using the commercial Computational Fluid Dynamics (CFD) software, Star-CCM+. The analysis highlights effective jointing methods that minimize drag forces by optimizing gap-filling techniques, thus comparing favourably to traditional coatings. The findings contribute significantly to advancing a UV-C hull fouling prevention system, promising reduced environmental impacts and enhanced operational efficiency in the shipping industry.
An emerging market? The European Maritime Industry’s View on Autonomous Maritime Systems: A Survey
Authors: Burmeister Hans-Christoph , Weisheit Jonathan , Kuechle Julius , Bluhm Luka-Franziska , Bergmann Michael
Published: October 2024

Autonomous Maritime Systems have significantly emerged in maritime research over the past decade. But how is this technology adapted by the maritime industry in business applications? Based on a product and application-focused literature review as well as an industrial survey among 52 companies, this paper gives insights into the industrial’s interest in this emerging technology for different maritime segments, their prioritized use cases as well as the main barriers for the emerging market according to the European Maritime Industry. Hereby, it assesses the technology adoption rate specifically for different segments, i.e. Ship Operators, Manufacturers, Ports, Shipbuilding, Offshore and (Hinterland) logistics.
Automation in the Maritime Transport System – A Framework for Planning Resilient Operations
Authors: Ramstad Lone S. , Marie Stene Trine , Fjørtoft Kay , Holte Even
Published: October 2024

Maritime transport systems (MTS) are becoming increasingly automated, integrated and complex. New technology, automation and autonomous systems will contribute to safer, greener, and more efficient transport systems. However, the advancements pose new challenges, and it is a need to understand and manage the potential brittleness and risks. Uncertainties and the unknown should be prepared for when planning the implementation of new technology.

Hence, this paper presents a framework to support the planning for resilient operations when introducing autonomy in a MTS. The framework is based on a resilient approach and is the first draft of a framework being developed within the research project Maritime Resilience Management of an Integrated Transport system (MARMAN).

The approach is intended to facilitate a process where MTS actors work systematically to identify challenges, clarify potential future measures, and prepares for integrating automation and autonomy in a system. The method emphasizes the needs for cooperation, coordination and integrated planning across different transport modalities, organizational boundaries and stakeholders. But also between humans and technology, focusing on the different levels of planning (i.e. strategic, tactical and operational), where the main objectives will be to increase resilience by coping with potential critical events. In addition, continuous learning and commitment between actors and how to use the new technology are crucial for enhancing resilience.
Research on Autonomous Collision Avoidance of USV Based on Improved APF Algorithm
Authors: Gu Chaohong , Feng Youbing , Zhong Weibo , Cai Litao , Chu Huiyan
Published: October 2024

Aiming at the problem of Unmanned Surface Vessel (USV) avoiding dynamic vessels on the sea surface, an Artificial Potential Field method based on Velocity Obstacle Method (VO-APF) was studied. Under the premise of complying with the Convention on the International Regulations for Preventing Collisions at Sea (COLREGs), the overlapping of ship domains is minimized. The Quaternion ship domain was introduced into VO to make it more suitable for collision avoidance judgment in the ship domain, and the collision avoidance time of the ship was predicted, and the reasonable obstacle avoidance point was finally obtained. The attraction function of the obstacle avoidance target point and the repulsion function of the ship domain based on the APF are set, and the USV is subjected to the repulsion force and attraction in the APF, and finally completes the whole dynamic ship collision avoidance task. In the simulation environment, VO, APF and VO-APF were compared in three different encounter situations. The results show that VO-APF can help USV to complete the collision avoidance task under the premise of complying with COLREGs, and the overlap time between USV’s own ship domain and the other ship domain is the shortest, and the safety degree is the highest.
Digital Twin Model Study of Piping Acoustic Induced Vibration Risk
Authors: Li Qi , He Mengfu , Qin Manqing , Lai Haibin
Published: October 2024

The research and calibration of digital twin models are crucial for developing an intelligent monitoring system for pipeline acoustic induced vibration. This study addresses the rapid assessment of acoustic induced vibration risks during the design stage using a digital twin model. First, the likelihood of failure (LOF) due to acoustic induced vibration was calculated based on EI guideline, providing a quantitative risk assessment. Concurrently, numerical simulations were conducted to validate these results. The findings show a high consistency between the two methods, indicating their complementary and validating roles. Therefore, the integrated use of methods based on EI guidelines and numerical simulation provides robust technical support for early-stage assessment of acoustic induced vibration risk in pipeline design, enhancing both accuracy and reliability of the evaluation, and laying a solid foundation for pipeline design and safety assurance.
Steam Pressure Control of Marine Boiler Based on AFSA-PSO-LSSVM
Authors: Yuan Xiemin , Huang Yinrong
Published: October 2024

To solve the problem that the main steam pressure fluctuates greatly when the load of the combustion control system of the marine main boiler changes suddenly, present a combined inverse control system of Support vector machine and PID to control the steam pressure intelligently. The inverse model of the nonlinear system identified by LSSVM is used as the feedforward controller and the PID controller is used as the feedback controller. The hybrid intelligent algorithm of artificial fish swarm Algorithm and particle swarm optimization is used to optimize the parameters of the control system. The AFSA algorithm is used to search the initial values of the parameters and the PSO algorithm is locally updated. Finally, the mechanism of the steam pressure control system of the marine boiler is modeled and simulated, and the algorithm models of AFSA-PSO-LSSVM-PID, AFSA-LSSVM-PID, PSO-LSSVM-PID and LSSVM-PID are established. The experimental results show that the AFSA-PSO-LSSVM-PID model has a good dynamic, stability, anti-interference ability and robustness.
ILKD: An Incremental Learning and Knowledge Distillation Framework for Coronavirus Risk Prediction
Authors: Shen Jiahao , Shen Ao , Huang Hao , Hou Yijie , Kou Zheng
Published: October 2024

The coronavirus pandemic has seriously affected public health and social order. Prediction methods based on machine learning can identify the infectivity phenotype and pandemic risk of coronavirus. Currently, six types of coronaviruses that infect humans have been discovered, with significant differences in viral genome sequences. Continuous genetic variation of the virus will lead to reduced performance of machine learning models and potential learning forgetting. To solve this challenge, we propose an incremental learning and knowledge distillation framework (ILKD). First, we employ Dna2Vec to extract virus features and encode the virus sequence into virus feature vector. Second, we use hierarchical clustering to continuously identify new coronavirus groups. Third, ILKD employ a combined strategy of incremental learning and knowledge distillation to transform the Back Propagation (BP) neural network to continuously learn and predict the phenotypes of human-to-human coronavirus infection. Experimental results show that ILKD can effectively alleviate the learning forgetting phenomenon. Further analysis reveals ILKD has better performance than other incremental learning models, and has important public health application value.
RAF-Unet: A Remote Sensing Identification Method for Forest Land Information with Modified Unet
Authors: Wang Zhiyuan , Chen Lingyan , Shen Wanling , Xiao Jiawen , Xu Zhanghua , Liu Jinfu
Published: October 2024

Carrying out remote sensing refinement identification of forest land in complex environment is of great significance for timely mapping of forest distribution. Aiming at the problem that remote sensing images have bias in the extraction of forest land information data, based on the semantic segmentation algorithm Unet, combining the ResNet50 deep learning network, the attention mechanism module and the feature pyramid structure, we construct RAF-Unet (ResNet+Attention+FPN+Unet) to improve the extraction of forest land information data. The ResNet50 classification network is used as the encoder of the Unet network to extract the feature maps at five different scales; then, the attention mechanism module is introduced in the decoder stage of the Unet network to extract the key task goal information by learning the weight values of the features; finally, the feature pyramid structure is used in the output stage of the encoder to fuse the information from the shallow network and the deep network to extract the remote sensing forest land information in the image. The results show that the RAF-Unet algorithm outperforms the Unet algorithm in all the indexes, with a precision of 95.24%, a recall of 91.80%, an F1-score value of 93.49%, an intersection over union of 87.63%, and an accuracy of 93.68%; the validity of the modules is verified by the ablation experiments, and the ResNet network, the attention mechanism, and the feature pyramid structure are all effective in improve the classification effect. It helps the forestry department to better manage and dynamically monitor forestry information, which is of great significance to the scientific development, utilization and protection of forest land resources.
Event Based Control for Network Security Systems Subject to Actuator Saturation
Authors: Zhang Gengyuan
Published: October 2024

As a typical nonlinear link, actuator saturation exists in most network security protection systems. It easily disrupts the closed-loop performance of the system, leading to instability. The event triggering control policy generally adopts an aperiodic sampling mechanism and transmits information only when the triggering condition is met, which can save system communication and computing resources. An event-triggered controller is designed for a network security system with actuator saturation, and the system stabilization is realized. The attractor domain of the system is estimated by solving optimization problems in the form of linear matrix inequalities. Simulation results show the validity of the conclusions obtained in this paper.
Design and Implementation of a Ka-Band Frequency Source Based on DS+DDS Hybrid Method
Authors: Qian Pei , Ye Balin
Published: October 2024

This article proposes a design scheme for a broadband agile frequency conversion Ka-band frequency source, which adopts a mixed frequency synthesis method of DS+DDS. This method combines the advantages of DDS such as fast frequency switching speed, small frequency step, and wide DS frequency bandwidth, and uses segmented filtering to effectively suppress the disadvantage of DDS spurious error. DS adopts an up conversion and double frequency doubling scheme to broaden the frequency band, with simple design and low cost. The deterioration of phase noise is offset by selecting a low phase noise PLL. Actual measurement shows that the output bandwidth of the frequency source is 8GHz, with spurious suppression ≤ −61dBc, frequency switching time ≤ 140ns, output power ≥ 15dBm, step frequency of 1MHz, and phase noise ≤ −100dBc/Hz@1kHz, meet the design requirements.
Thermal conductivity of insulating materials using a peltier cell based cooling system
Authors: Guzman A , Garcia F , Puma A , Gomez-Leon M , Palo-Tejada E
Published: October 2024

In this work we have built and evaluated a system that allows us to determine the thermal conductivity of insulating materials. We use this system to study the thermal properties of suitable for building materials, typical of high altitude Andean regions.

The equipment’s setup is of a Guarded Hot Plate Apparatus (GHPA), the equipment’s central part has a circular hot plate and a concentric crown shaped disc (guard), which are not in contact each other. Two circular samples are placed on both sides of the hot plate and then the square cold plates are mounted at the lower and upper sides of the samples.

The cold plates are refrigerated by mean of liquid which flows through an spiral coil embedded in it. The liquid is cooled by Peltier cells whose hot sides are in contact with air radiators. The temperature’s gradient is measured between the hot plate and the guard with a Type E thermocouple and to measure the temperature of the cold plates Type K thermocouples are used. To show the equipment’s performance, some thermal conductivity tests were carried out on the following materials: sugar cane bagasse, adobe with Stipa ichu, ashlar and glass.
Structural and functional model of formation of STEM-competencies of students of professional higher education institutions in mathematics teaching
Authors: Pylypenko O S , Kramarenko T H
Published: October 2024

This study focuses on the vocational preparation of learners in professional pre-higher educational establishments. The primary objective is to provide a theoretical foundation for, construct, and empirically evaluate the efficacy of a structural-functional paradigm for cultivating STEM proficiencies among students in these institutions through mathematics instruction. The pedagogical experiment corroborated the research postulate that attaining advanced STEM competencies in mathematics among professional pre-higher education students can be facilitated through a learning model that incorporates specific pedagogical conditions: motivating and stimulating students to engage in educational, cognitive and research activities in mathematics through engagement in cooperation and the use of individual and group coaching; implementation of STEM projects in mathematics teaching; usage of ICT to ensure visibility and research orientation of mathematics teaching. The experimental outcomes and accompanying educational resources have enabled a comprehensive analysis of the challenges associated with implementing STEM methodologies in mathematics instruction. This article aims to elucidate the key attributes of the devised structural-functional model and evaluate its implementation efficacy, with particular emphasis on the application of the authors’ developed pedagogical support materials.
The use of visualization technologies in the study of the probability of life on exoplanets
Authors: Malchenko S L , Mykoliuk D V , Salivon S O
Published: October 2024

The modern generation receives a significant amount of information from various sources daily. The information received should be perceived and analyzed, and conclusions drawn. Young people prefer visual technologies that allow them to obtain and analyse dynamic details quickly. The educational process should not lag; on the contrary, it should prepare a thinking, creative person who can easily use modern digital technologies. This paper discusses the use of the Universal Sandbox 2 universe simulator in the study of astronomy, namely the search for exoplanets and the study of the conditions necessary for the existence of life on them.
The transformation of children’s mental representations of 5-6 year olds for coagulation: precursor models through a storytelling approach
Authors: Kaliampos G , Ioannou M , Pantidos P , Ravanis K
Published: October 2024

The current study presents the results of a qualitative research on the mental representations of children aged 5-6 years regarding the coagulation of everyday materials. Initially, children’s representations on coagulation of butter and chocolate were studied in a pre-test through three different tasks. Subsequently, a teaching intervention was implemented based on a storytelling approach, which is embedded in a socio-constructivist perspective with the aim of establishing a precursor model in children’s thinking about coagulation. Finally, in a post-test, children’s representations after the teaching intervention were studied. The results of the research showed that children have made significant progress in the post-test as the majority of them recognize cooling as a factor in the coagulation of the above materials.
The use of computer modeling in the educational process based on the example of studying Coulomb’s law
Authors: Velychko V Ye , Kaidan V P , Kaidan N V , Fedorenko O G
Published: October 2024

The study analyzes computer modeling tools intended for use in educational and scientific contexts. The concept of modeling as a method of research and a teaching tool is examined, the emphasis is placed on computer modeling. It is shown how physical laws, particularly Coulomb’s law, can be studied through modeling. The study uses pre-made simulators, spreadsheets, mathematical packages, as well as our own software in Object Pascal and Python. Experimental testing has confirmed the effectiveness of computer modeling in teaching natural sciences. A survey of students and teachers showed interest in further use of simulation tools in the educational process.
Ontological analysis of business process modeling of higher education institutions based on the electronic document management system
Authors: Shpakov A V , Gorda O V , Honcharenko Y O
Published: October 2024

Improving the quality of the educational process, bringing it to modern requirements is a complex task, the solution of which requires a systematic approach from higher education institutions and the development of a strategy to improve the quality of service and efficiency of the institution. Formalization and modeling of the management business process allows for effective management decisions. When analyzing large amounts of information to effectively solve the problem of data structuring, as well as the problem of forming new knowledge, it is proposed to use an ontological approach based on the use of associative rules. The ontological analysis of modeling business processes of higher education institutions and analysis of the structure, functions and information flows of organization and management of educational activities based on the structural approach is carried out. Improving the quality of the educational process, bringing it to modern requirements is a complex task, the solution of which requires a systematic approach from higher education institutions and the development of a strategy to improve the quality of service and efficiency of the institution. The use of an ontological model of interaction between subjects and objects of the system makes it possible to assess the level of system efficiency and build a simulation model of management, which will allow predicting the emergence of critical business processes that may lead to a decrease in the efficiency of decision-making and disruptions in the functioning of higher education institutions and their departments.
Experience of conducting integrated irregular classes in robotics
Authors: Valko N V , Kushnir N O
Published: October 2024

In the modern world of electronic devices, a person can bring to life any projects that make their life more comfortable and safe. The basis for such solutions is robotics. Creating and programming a robot today is quite simple. We offer the experience of conducting long-term projects that can take place in summer camps, scientific studios, and extracurricular clubs. The uniqueness of such activities lies in the combination of various types of work that help explore the topic and conduct scientific and technological research. Mastering robotics technology and understanding the principles of their operation is an important aspect of preparing modern children for a safe life in a high-tech world and successful self-realization. The foundation for the study and effective application of these technologies is mathematics, physics, engineering, and programming. Therefore, STEM education, aimed at developing competencies demanded in society, increasing motivation to study traditionally challenging subjects of the natural-mathematical cycle, is of particular importance. The peculiarity of this approach to education is project activity and transdisciplinarity, contributing to the formation of teamwork skills, critical thinking, and a comprehensive understanding of the researched problem. The article presents the experience of a volunteer project to teach robotics to children from Ukraine. Organizational conditions for conducting classes, typical difficulties, examples of projects, and the lesson scenario are provided. The proposed approach to organizing education is based on years of practical experience and can be used by educational institutions and non-profit organizations.
Virtual laboratories for study technologies of environmental protection
Authors: Levytska T O , Ye Piatykop O , Khliestova O A , Bilenko A P
Published: October 2024

This work is devoted to the use of virtual work for teaching bachelors in technologies of environmental protection. An analysis of publications in the field of using virtual laboratories in universities was carried out. The use of virtual laboratory work supports modern approaches to education, stimulates the learning process and creates conditions for more effective mastery of the material. The article describes an example of the development of laboratory work to determine the parameters of the dispersed composition of dust. Virtual laboratory work is developed as a web application, has a user-friendly interface, all data is saved into a database. Students can work at their own pace, repeat experiments, and adapt their approach to learning. The presented virtual laboratory is relevant to use in distance learning.
The formation of visual thinking of students in technical universities in the context of higher mathematics education
Authors: Klochko V I , Bondarenko Z V , Kyrylashchuk S A , Prozor O P , Kyrylashchuk T H
Published: October 2024

The visualisation of teaching higher mathematics as a development of information and communication technologies determines the transition of the educational process to a new level of its development. As a result, it should focus on the visual orientation and modern practice of its use. The question arises as to the formation of students’ visual thinking as a necessary component of the training of a modern specialist. In this context, a study has been conducted on the problem of using visual information and its visual perception in teaching higher mathematics on the example of individual sections, as well as techniques of justification based on visual information. The examples offered in the article form the skills of working with graphic information. Developing visual thinking, they fix attention during the learning process, implicitly and indirectly contributing to the conversion of mental content into a visual image, ensuring the formation of a more complete picture of an image or concept. The article analyses the results of using visualisation in the educational process of students of technical universities. The influence of visualisation on the level of students’ knowledge is analysed. In particular, the ability of a certain contingent of students to perceive and use visual images, their ability to think and express thoughts in images, perceive the content of logic, emotions contained in visual information, as well as the ability to operate with visual images in communication, establish cause and effect relationships and relations between concepts, as well as memorise and reproduce ideas about objects is noted.
Effect of ultrasonic shot peening on microstructure and properties of Cu-Ti alloy
Authors: Huang ZiXin , Liu Lingling , Wang Xiang , Zhang Yang , Li Xiaoxian , Zhang Xuehui
Published: October 2024

Modified surface layers with refined grain size and high microhardness characteristics were prepared on Cu-Ti alloy using ultrasonic shot peening (USP) by controlling the shot diameter. The phase structure and organization morphology of the modified layer were analyzed using x-ray diffraction (XRD), optical microscopy (OM) and scanning electron microscope (SEM). The microhardness, wear resistance and corrosion resistance were systematically characterized. The results showed that the comprehensive surface properties of the sample was optimized at a shot diameter of 3.0 mm. The average grain size was refined to 12.4 nm under the high-frequency impact of steel balls. Owing to the grain refinement and work hardening, the surface microhardness, wear resistance and corrosion resistance of the sample was significantly improved. Among these, the surface microhardness of the sample was enhanced from 257.68 HV0.1 to 313.51 HV0.1, the volume wear rate was decreased from 0.3305 um2 N−1 to 0.1707 um2 N−1, and the self-corrosion current density was also decreased from 1.658 × e−5 mA μm−2 to 4.053 × e−6 mA μm−2. It is proved that USP is one of the effective methods for preparing Cu-Ti alloys with excellent surface properties.
7-axis synchronization-integrated on-the-fly laser texturing system of freeform surface: design and development
Authors: Ma Wenqi , Zhang Jinmiao , Zhao Liang , Hu Zhenjiang , Zhao Xuesen , Sun Tao , Zhang Junjie
Published: October 2024

While laser surface texturing (LST) is a promising manufacturing technique for surface functionalization, simultaneously realizing high precision and high efficiency in the LST of complex curved surface is challenging, due to continuously varied geometries of laser-matter incidence. In the present work, we propose a novel manufacturing system of 7-axis on-the-fly LST for complex curved surface, based on the integrated synchronization of 5-axis linkage motion platform with 2-axis galvanometer. Specifically, the algorithm for decomposing spatial texture trajectory on curved surface into low-frequency and high-frequency parts is established, based on which the kinematic model of synchronized 7-axis system is developed to derive the motion of each axis in both 5-axis linkage motion platform and 2-axis galvanometer simultaneously. Subsequently, the synchronized 7-axis LST system is experimentally realized, including the setup of mechanical stages integrated with optical path, the configuration of numerical control unit, and the development of processing software. Finally, case study of 7-axis on-the-fly LST of freeform aluminum surface is performed, and the advantages in terms of processing efficiency and texturing accuracy over 5-axis linkage LST are demonstrated. The correlation of reduced following errors between mechanical stages with the promoted performance of curved surface texturing by the 7-axis on-the-fly LST is further analyzed. Current work provides a feasible solution for establishing the manufacturing system for high performance LST of complex curved surface.
Artificial hearing systems based on functional cochlea models
Authors: Chang Jinke , Clark Sita Tarini , Roberts Iwan , Hrncirik Filip , Zhang Zhipeng , Bance Manohar
Published: October 2024

The cochlea is one of the most complex organs in the human body, exhibiting a complex interplay of characteristics in acoustic, mechanical, electrical, and biological functions. Functional cochlea models are an essential platform for studying hearing mechanics and are crucial for developing next-generation auditory prostheses and artificial hearing systems for sensorineural hearing restoration. Recent advances in additive manufacturing, organ-on-a-chip models, drug delivery platforms, and artificial intelligence have provided valuable insights into how to manufacture artificial cochlea models that more accurately replicate the complex anatomy and physiology of the inner ear. This paper reviews recent advancements in the applications of advanced manufacturing techniques in reproducing the physical, biological, and intelligent functions of the cochlea. It also outlines the current challenges to developing mechanically, electrically, and anatomically accurate functional models of the inner ear. Finally, this review identifies the major requirements and outlook for impactful research in this field going forward. Through interdisciplinary collaboration and innovation, these functional cochlea models are poised to drive significant advancements in hearing treatments, and ultimately enhance the quality of life for individuals with hearing loss.
Positioning errors and accuracy of CNC machine tools
Authors: El Melegy A , Younes M A
Published: October 2024

Computerized numerically controlled (CNC) machine tools are a solid foundation for modern industrial manufacturing. These machines provide linear and angular displacements in three or five axes. The accuracy of moving and positioning the tooltip relative to the work part’s surface determines the final product’s accuracy. Errors due to machine positioning can be linear or angular or both. This work studies the positioning errors of a vertical turning center CNC machine type. This machine has three axes, two linear X (horizontal) and Z (vertical), and one rotation axis ‘C’. The travel of the spindle carrying the cutting tool along the X-axis is 1400 mm, and the travel of the carriage holding the spindle along the Z-axis is 1300 mm divided into six latches. The machine rotary table which carries the work part can rotate 360°. A highly precise laser interferometer system determines the linear positioning errors in both the X and Z axes. The angular positioning errors for the ‘C’ rotation axis are determined accurately by an autocollimator system. The positioning error measurements are carried out based on ISO 230–2 as a measurement standard of positioning deviation, accuracy, and repeatability. The collected error measurements in linear displacements and angular rotation are analyzed, interpreted, and compared with manufacturer specifications and ISO 13041–4 allowable tolerances.
Layered high-entropy sulfides: boosting electrocatalytic performance for hydrogen evolution reaction by cocktail effects
Authors: Lin Ling , Ding Ziming , Karkera Guruprakash , Diemant Thomas , Chen Dong-Hui , Fichtner Maximilian , Hahn Horst , Aghassi-Hagmann Jasmin , Breitung Ben , Schweidler Simon
Published: October 2024

This study explores high-entropy sulfides (HESs) as potential electrocatalysts for the hydrogen evolution reaction (HER). Novel Pa-3 and Pnma structured HESs containing Fe, Mn, Ni, Co and Mo, were synthesized via a facile mechanochemical method. Structural and chemical properties were extensively characterized using x-ray diffraction, transmission electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray photoelectron spectroscopy. The electrocatalytic performance of four as-prepared HESs in alkaline electrolyte for HER reveals the remarkable outperformance compared to medium-entropy and conventional sulfides. Particularly, (Fe0.2Mn0.2Ni0.2Co0.2Mo0.2)S2 demonstrated outstanding activities, with minimal overpotentials (187 mV at 10 mA cm–2) and outstanding durability under harsh alkaline conditions (a mere polarization increase ΔE = 17 mV after 14 h via chronopotentiometry). The remarkable catalytic activities can be attributed to synergistic effects resulting from the cocktail effects within the high-entropy disulfide. The introduction of Mo contributes to the formation of a layered structure, which leads to an increased surface area and thus to a superior HER performance compared to other HES and conventional sulfides. This work demonstrates the promising potential of HES and underscores that further development for catalytic applications paves the way for innovative routes to new and more efficient active materials for HER catalysis.
Recent advances in branching problems of representations
Authors: Kobayashi Toshiyuki
Published: October 2024

How does an irreducible representation of a group behave when restricted to a subgroup? This is part of branching problems, which are one of the fundamental problems in representation theory, and also interact naturally with other fields of mathematics.

This expository paper is an up-to-date account on some new directions in representation theory highlighting the branching problems for real reductive groups and their related topics ranging from global analysis of manifolds via group actions to the theory of discontinuous groups beyond the classical Riemannian setting.

This article is an outgrowth of the invited lecture that the author delivered at the commemorative event for the 70th anniversary of the re-establishment of the Mathematical Society of Japan, and originally appeared in Japanese in Sugaku 71 (2019).
Morphometric analysis of actin networks
Authors: Akenuwa Oghosa H. , Gu Jinmo , Nebenführ Andreas , Abel Steven M.
Published: October 2024

The organization of cytoskeletal elements is pivotal for coordinating intracellular transport in eukaryotic cells. Several quantitative measures based on image analysis have been proposed to characterize morphometric features of fluorescently labeled actin networks. While helpful in detecting differences in actin organization between treatments or genotypes, the accuracy of these measures could not be rigorously assessed due to a lack of ground-truth data to which they could be compared. To overcome this limitation, we utilized coarse-grained computer simulations of actin filaments and cross-linkers to generate synthetic actin networks with varying levels of bundling. We converted the simulated networks into pseudofluorescence images similar to images obtained using confocal microscopy. Using both published and novel analysis procedures, we extracted a series of morphometric parameters and benchmarked them against analogous measures based on the ground-truth actin configurations. Our analysis revealed a set of parameters that reliably reports on actin network density, orientation, ordering, and bundling. Application of these morphometric parameters to root epidermal cells of Arabidopsis thaliana revealed subtle changes in network organization between wild-type and mutant cells. This work provides robust measures that can be used to quantify features of actin networks and characterize changes in actin organization for different experimental conditions.
Spatiotemporal analysis of F-actin polymerization with micropillar arrays reveals synchronization between adhesion sites
Authors: Hollander Sarit , Guo Yuanning , Wolfenson Haguy , Zaritsky Assaf
Published: October 2024

We repurposed micropillar arrays to quantify spatiotemporal inter-adhesion communication. Following the observation that integrin adhesions formed around pillar tops we relied on the precise repetitive spatial control of the pillars to reliably monitor F-actin dynamics in mouse embryonic fibroblasts as a model for spatiotemporal adhesion–related intracellular signaling. Using correlation-based analyses, we revealed localized information flows propagating between adjacent pillars that were integrated over space and time to synchronize the adhesion dynamics within the entire cell. Probing the mechanical regulation, we discovered that stiffer pillars or partial actomyosin contractility inhibition enhances inter-adhesion F-actin synchronization, and that inhibition of Arp2/3, but not formin, reduces synchronization. Our results suggest that adhesions can communicate and highlight the potential of using micropillar arrays as a tool to measure spatiotemporal intracellular signaling.
Ernst Mach
Authors: Beiser Frederick C
Published: October 2024

This chapter is a reexamination of Ernst Mach. It argues that the reasons for Mach’s fame lie less in his achievements for science but in his skepticism about the achievements of science. Mach was skeptical about the finality and authority claimed for science; he was a critic especially of the dogmatism of science. Although his work on mechanics is seen as the model of scientific exposition and method, Mach was extremely skeptical of the claims made for mechanics. Mach was an early advocate of the history of science, claiming that history was the key for an understanding of a scientific theory. This chapter also examines Mach’s theory of sensation; his empiricism and his critique of atomism. The final section is a critical account of Lenin’s critique of Mach.
motifbreakR v2: expanded variant analysis including indels and integrated evidence from transcription factor binding databases
Authors: Coetzee Simon G , Hazelett Dennis J
Published: October 2024

Motivation

motifbreakR scans genetic variants against position weight matrices of transcription factors (TFs) to determine the potential for the disruption of binding at the site of the variant. It leverages the Bioconductor suite of software packages and annotations to query a diverse array of genomes and motif databases. Initially developed to interrogate the effect of single-nucleotide variants on TF binding sites, in motifbreakR v2, we have updated the functionality.

Results

New features include the ability to query other types of complex genetic variants, such as short insertions and deletions. This capability allows modeling a more extensive array of variants that may have significant effects on TF binding. Additionally, predictions based on sequence preference alone can indicate many more potential binding events than observed. Adding information from DNA-binding sequencing datasets lends confidence to motif disruption prediction by demonstrating TF binding in cell lines and tissue types. Therefore, motifbreakR can directly query the ReMap2022 database for evidence that a TF matching the disrupted motif binds over the disrupting variant. Finally, in motifbreakR, in addition to the existing interface, we implemented an R/Shiny graphical user interface to simplify and enhance access to researchers with different skill sets.

Availability and implementation

motifbreakR is implemented in R. Source code, documentation, and tutorials are available on Bioconductor at https://bioconductor.org/packages/release/bioc/html/motifbreakR.html and GitHub at https://github.com/Simon-Coetzee/motifBreakR.
EuDockScore: Euclidean graph neural networks for scoring protein–protein interfaces
Authors: McFee Matthew , Kim Jisun , Kim Philip M
Published: October 2024

Motivation

Protein–protein interactions are essential for a variety of biological phenomena including mediating biochemical reactions, cell signaling, and the immune response. Proteins seek to form interfaces which reduce overall system energy. Although determination of single polypeptide chain protein structures has been revolutionized by deep learning techniques, complex prediction has still not been perfected. Additionally, experimentally determining structures is incredibly resource and time expensive. An alternative is the technique of computational docking, which takes the solved individual structures of proteins to produce candidate interfaces (decoys). Decoys are then scored using a mathematical function that assess the quality of the system, known as scoring functions. Beyond docking, scoring functions are a critical component of assessing structures produced by many protein generative models. Scoring models are also used as a final filtering in many generative deep learning models including those that generate antibody binders, and those which perform docking.

Results

In this work, we present improved scoring functions for protein–protein interactions which utilizes cutting-edge Euclidean graph neural network architectures, to assess protein–protein interfaces. These Euclidean docking score models are known as EuDockScore, and EuDockScore-Ab with the latter being antibody–antigen dock specific. Finally, we provided EuDockScore-AFM a model trained on antibody–antigen outputs from AlphaFold-Multimer (AFM) which proves useful in reranking large numbers of AFM outputs.

Availability and implementation

The code for these models is available at https://gitlab.com/mcfeemat/eudockscore.