Structural Principles Research Articles

Glass and Liquid Chemistry of Coordination Polymers and MOFs

Abstract The chemistry of coordination polymers and metal-organic frameworks (MOFs) has progressed largely with the development of crystallography. The study of “disordered systems” such as the liquid and glassy states of coordination polymers and MOFs has been developed in recent years, and various methods have been recognised to produce glasses from crystals. The structures of the glass and liquid phases are studied using synchrotron radiation X-rays and spectroscopy. Many of them have the coordination bond-based network structure found in the crystal structures. This suggests that the structural design principles of coordination chemistry can be applied to glasses and liquids of coordination polymers and MOFs. The inherent properties of the disordered system, such as wide compositions and high internal degrees of freedom, high material formability and softness, contribute to the coupled physicochemical properties.

Examining the Role of Motivation, Attitude, and Self-Efficacy Beliefs in Shaping Secondary School Students’ Academic Achievement in Science Course

The aim of this study is to examine the effect of motivation, attitude, and self-efficacy beliefs of secondary school students towards science course on their academic achievement. The relational survey model was used to conduct the study. A total of 635 students, 319 females, and 316 males participated in the study. “Motivation Scale for Learning Science”, “Self-Efficacy Scale for Science”, “Attitude Scale for Science Course” were used as data collection tools. In the study, independent t-test was used to make comparisons in terms of gender, and path analysis using structural equation modeling principles was conducted to determine the direction and level of the relationship between the variables. In the results of the research, significant differences were found in students’ attitudes, motivation, and self-efficacy in terms of the gender variable. It was concluded that students’ attitudes and motivation directly affect their academic achievement. There was a strong positive relationship between attitude and motivation, a low positive relationship between self-efficacy and attitude, and a moderate positive relationship between self-efficacy and motivation. In line with the results of this research, and considering the direct effects of academic achievement on students’ motivation in science course, it is recommended that necessary information and training activities be provided to teachers in order to carry out studies on increasing students’ motivation.

Design of Temperature Monitoring System for Air Cooled Radiators Based on LoRa

Air cooling technology is widely used in the north. When the winter temperature in the north is too low, the cooling radiator is prone to freezing, leading to the inability of air cooling units to operate normally and causing huge economic losses. In response to the above issues, this article designs a monitoring system for air cooled radiators based on LORA communication, based on Internet of Things technology. Analyze the A-type tower structure and heat dissipation principle of the air-cooled condenser, reasonably select the temperature measurement point position, and achieve temperature data transmission through LoRa communication and Ethernet communication technology. The monitoring software is programmed in C # language, which can visually display the temperature distribution information of the air-cooled condenser and store data in real time. The experimental results indicate that the system has certain guiding significance for preventing the freezing phenomenon of air cooled condensers and optimizing operation.

Interaction Principle of Rock-Bolt Structure and Rib Control in Large Deformation Roadways

Interaction Principle of Rock-Bolt Structure and Rib Control in Large Deformation Roadways

Design and dynamics of a 2PSS+PSR+SP+RUPUR-type parallel rotor of helicopter

A novel parallel rotor of the helicopter is designed by combining a 2PSS+PSR+SP+RUPUR-type parallel manipulator with a rotor of the helicopter. Its kinematics and dynamics models are established. Firstly, the structure principle and the merit performances of the parallel rotor are explained by comparing with conventional and existing rotors of the helicopter, and the degree of freedom of the parallel manipulator is calculated. Secondly, the kinematics formulas are derived for solving the displacement, Jacobian matrix, general velocity, Hessian matrix, and acceleration of the parallel rotor and the kinematic limbs. Thirdly, a dynamics model of the parallel rotor is established based on the derived kinematics formulas. Finally, the theoretical kinematics and dynamics solutions are verified by a simulation mechanism of the parallel rotor of the helicopter.

Cascade Defluorination of Perfluoroalkylated Catholytes Unlocks High Lithium Primary Battery Capacities

AbstractExceeding the energy density of lithium−carbon monofluoride (Li−CFx), today's leading Li primary battery, requires an increase in fluorine content (x) that determines the theoretical capacity available from C−F bond reduction. However, high F‐content carbon materials face challenges such as poor electronic conductivity, low reduction potentials (<1.3 V versus Li/Li+), and/or low C−F bond utilization. This study investigates molecular structural design principles for a new class of high F‐content fluoroalkyl‐aromatic catholytes that address these challenges. A polarizable conjugated system—an aromatic ring with an alkene linker—functions as electron acceptor and redox initiator, enabling a cascade defluorination of an adjacent perfluoroalkyl chain (RF = −CnF2n+1). The synthesized molecules successfully overcome premature deactivation observed in previously studied catholytes and achieve close‐to‐full defluorination (up to 15/17 available F), yielding high gravimetric capacities of 748 mAh g−1fluoroalkyl‐aromatic and energies of 1785 Wh kg−1fluoroalkyl‐aromatic. The voltage compatibility between fluoroalkyl‐aromatics and CFx enables design of hybrid cells containing C−F redox activity in both solid and liquid phases, with a projected enhancement of Li–CFx gravimetric energy by 35% based on weight of electrodes+electrolyte. With further improvement of cathode architecture, these “liquid CFx” analogues are strong candidates for exceeding the energy limitations of today's primary chemistries.

Thrust Coordinated Assignment and Ripple Suppression of a Multiple-Modular Permanent Magnet Linear Synchronous Motor Based on Model Predictive Thrust Control

This paper presents a model predictive thrust force control (MPTFC) method for a multiple-modular permanent magnet synchronous linear motor (PMSLM). It focuses on the thrust assignment and thrust ripple of the motor drive system with a multiple-branch inverter. A discrete time model of the PMSLM is established, and the driving system structure and operation principle of the motor are studied. A multi-mode cost function is designed according to the requirements of the different load conditions, and the optimal voltage vector action time is determined. The operation mode is analyzed to determine the distribution factor, so as to reduce the thrust pulsation during operation and improve the performance of the drive system. The results indicate that the proposed MPTFC method is effective in different operating modes, and the drive system has high efficiency and safer performance compared to a conventional drive system.

Rumbo a una metafísica homérica

This article explores some general notions of what could be called a “Homeric metaphysics”, as it underlies the poems, setting some philosophical problems. In the first place, the Homeric arché is analyzed as the explanatory principle of the gods and the totality of the cosmos through theogonic and cosmogonic allusions in the Iliad. Then, the structural principles of the divine order and its projection in the human and natural cosmos are presented, closely linked to the limits of Zeus’s power as ruler of the universe, along with its direct implications on the political level. Thirdly and lastly, the notion of time in the poems is briefly analyzed, as a metaphysical concept that operates in human reality and on which an ethical-existential dimension of the hero is projected, as will be seen in the case of Achilles.

Analysis of Vortex Evolution in the Runner Area of Water Pump Turbine under Runaway Conditions

In order to study the evolution principle of the coherent structure in the low flow rate runaway condition, the pump turbine of a certain pumped storage power plant was employed. The transient dynamic stress of the runner was numerically simulated and examined in this study in order to analyze the coherent structure of the vortex and the stability of the grid connection during the transition process. Based on the realizable k-ε turbulent model, the unsteady flow of the whole pump turbine channels was calculated. The results show that the flow in the runner channels presents with a turbulence state, and with many different scales vortices. These vortex structures are mainly distributed in the inlet region of the blade, the area of the blade trailing edge and the middle section of the runner channels. These vortex structures affect the distribution of the blade pressure load. Moreover, the vortex structure at the inlet of the runner depends on the change in the attack angle. In the flow region formed at the outlet of the blade near the suction surface and the runner cone, the blade has a limited effect on the fluid; thus, the vortex structure depends on the Coriolis force and the centrifugal force joint action. The evolution of these vortex structures will have a greater impact on the grid connection of the power station. During the operation of the power station, it is necessary to reduce the time of transitional conditions so that the power station can operate efficiently.

Evaluation of strengthening approaches on a cultural heritage building in the context of structural performance and restoration principles

Mimari mirasın yaşatılarak gelecek nesillere aktarılması, özgün niteliklerin yanı sıra yapısal bütünlüğün de korunmasını gerektirir. Zamanla ortaya çıkan çeşitli hasarlar, yapıların ilk inşa döneminde sahip oldukları strüktürel performansın azalmasına, deprem gibi anlık etkilerle kısmi veya bütüncül yıkılmalara sebep olmaktadır. Güçlendirme, güvenlik seviyesinin işlev değişikliği ya da standartlar gereğince yükseltilmesini amaçlayan strüktürel müdahalelerdir. İyileştirme veya güçlendirmelerde, yapısal performansın artırılmasının yanı sıra, özgünlüğün de azami düzeyde gözetilmesi gerekir. Çalışma kapsamında, İzmir, Konak İlçesi’nde bulunan ve işlev değişikliği sebebiyle güçlendirilen yapıdaki olası performans değişikliği, sayısal model ve analiz yöntemiyle incelenerek, güvenlik düzeyinin anlamlı düzeyde arttığı belirlenmiştir. Elde edilen verilerin mühendislik dışı disiplinler tarafından da yorumlanabilir sadelikte olması hedeflenmiştir. Güçlendirme uygulaması restorasyonun temel ilkeleri bağlamında değerlendirilmiş, müdahalelerin ihtiyatla gerçekleştirildiği, özgünlük - güvenlik ilişkisinin optimize edildiği, mimari bütünlüğe zarar verilmediği sonucuna varılmıştır.

Structural design and engineering of Striatus, an unreinforced 3D-concrete-printed masonry arch bridge

This paper describes the structural design and engineering of “Striatus”, a 3D-concrete-printed unreinforced masonry pedestrian bridge built in Venice in 2021 as part of the Time Space Existence exhibition organised by the European Cultural Centre. The project combines the latest developments in 3D concrete printing with the structural principles of historic unreinforced masonry. Typically, the structural applications of 3D concrete printing are limited to elements such as columns and walls loaded vertically, perpendicularly to the horizontal printing layers, to formwork elements or secondary structural elements. Indeed, fabrication constraints, delamination issues and the low tensile strength of the concrete have been seen as limiting factors to 3D concrete printing for structural applications demanding resistance to bending or predominant loading directions not perpendicular to the printing layers. By using unreinforced-masonry structural principles, this paper shows that structural elements spanning space horizontally, such as a pedestrian bridge, can be built by using the 3D concrete printing components as the main structure, working only in compression, loaded perpendicularly to the printed layers. Furthermore, as a compression-only structure following masonry principles, Striatus enabled the use of unreinforced concrete without any mechanical or chemical connections between the elements and the separation of concrete and steel, only used for the supports and to equilibrate the horizontal thrust of the arch effect through the tension ties. This work shows how the application of unreinforced masonry principles to 3D concrete printing offers new opportunities in terms of structural design and represents a strategy to increase sustainability by reducing material consumption and allowing reusability and recyclability of the structure. Finally, this paper discusses the critical aspects related to the design of Striatus from an engineering and construction point of view.

Convolutional neural networks for vision neuroscience: significance, developments, and outstanding issues.

Convolutional Neural Networks (CNN) are a class of machine learning models predominately used in computer vision tasks and can achieve human-like performance through learning from experience. Their striking similarities to the structural and functional principles of the primate visual system allow for comparisons between these artificial networks and their biological counterparts, enabling exploration of how visual functions and neural representations may emerge in the real brain from a limited set of computational principles. After considering the basic features of CNNs, we discuss the opportunities and challenges of endorsing CNNs as in silico models of the primate visual system. Specifically, we highlight several emerging notions about the anatomical and physiological properties of the visual system that still need to be systematically integrated into current CNN models. These tenets include the implementation of parallel processing pathways from the early stages of retinal input and the reconsideration of several assumptions concerning the serial progression of information flow. We suggest design choices and architectural constraints that could facilitate a closer alignment with biology provide causal evidence of the predictive link between the artificial and biological visual systems. Adopting this principled perspective could potentially lead to new research questions and applications of CNNs beyond modeling object recognition.

Buckling performance of thin-walled filled steel columns

Concrete-filled composite elements have recently gained popularity as beams and columns all over the world. They have advantages similar to reinforced concrete elements, such as the moulding process and the lack of maintenance of the filled concrete, as well as advantages similar to hollow steel elements, such as enhancing compressive strength and bending capacity by using smaller sections. In this paper, the buckling behaviour of thin-walled steel columns with circular cross-section and different filling materials was investigated under uniaxial load. Six different materials (concrete produced using normal aggregate, concrete produced using waste aggregate, waste fine aggregate, waste coarse aggregate, waste iron dust and polyurethane) were used as filling. Filled columns were compared experimentally with hollow thin-walled steel columns that had the same height and diameter. All specimens had the same length (750 mm), same diameter (60.3mm) and the same wall thickness (3mm). Experimental results were compared with analytical results obtained from a calculation done using the national steel design code, Design, Calculation and Construction Principles of Steel Structures 2016. Additionally, columns specimens were modelled in Abaqus software. Conservative and consistent results were obtained from comparing experimental, analytical, and numerical results.

Design and Simulation Analysis of Piezoelectric Ceramic Tube-Based Fiber Optic Nutator Applied to an Intersatellite Laser Communication System

The signal-receiving end of acquisition, pointing, and tracking (APT) systems applied to intersatellite laser communication terminals usually uses a fast-steering mirror (FSM) to control the fiber-coupling process, has a complex structural design, and induces large errors in the nonideal coaxial optical path. Herein, we propose a fiber-optic nutator using a piezoelectric ceramic tube (PCT) as the driving unit that allows scanning in the focal plane of the light signal to achieve active fiber coupling in the APT system. Specifically, this article describes the structural design principle of a PCT-based fiber optic nutator, establishes a simulation model of the mechanism, and proves the correctness of the simulation model by measuring the deflection angle of a PCT based on a parallel light collimator. The minimum accuracy of the designed nutator was 0.145 μm, the maximum nutation radius R was 20.09 μm, and the maximum nutation bandwidth was 20 kHz, as determined through simulation. Finally, the design parameters of the nutator were evaluated. The PCT-based fiber optic nutator, which met the design parameters, structurally replaced the fiber optic coupling component FSM and fine tracking camera in conventional APT systems successfully. Therefore, the PCT-based fiber optic nutator allows the active coupling control of signal light to a single-mode fiber (SMF) based on energy feedback on a theoretical basis and promotes the lightweight design of relay optical paths in APT systems. In addition, with future work in optimization of the nutation control algorithm, the scanning range and accuracy of the nutator can be improved.

Nonlinear dynamic characteristics of two-dimensional micro-positioning workbench based on giant magnetostrictive actuators

Studying the nonlinear dynamic characteristics of multi-field coupling of the giant magnetostrictive actuator (GMA) is one of the main ways to improve its output performance. Because of the problem that its multi-field coupling nonlinear dynamic characteristics are difficult to accurately describe, the multi-field coupled nonlinear dynamic model of GMA and two-dimensional micro-positioning workbench is established according to the Jiles–Atherton hysteresis model, magnetostrictive model, hysteresis nonlinear magnetic equation and the structural dynamics principle of GMA, respectively. The influence of equivalent damping coefficient, equivalent stiffness, and equivalent mass on the dynamic characteristics of each model is analyzed, and finally, the constructed model and the obtained law are experimentally verified. The results show that the displacement curve calculated by the model is consistent with the experimentally measured displacement curve, the influence of the equivalent damping coefficient, equivalent stiffness, and equivalent mass on the dynamic characteristics of the model measured by the experiment is consistent with the simulation analysis results, and the maximum error of the output displacement is 1.779 um, which verifies the correctness of the model. The research results provide a theoretical basis for improving the dynamic characteristics of GMA and improving the output performance of two-dimensional micro-positioning workbenches.

Syncretism and synaesthesia in music – unification of arts and perceptions

Archaeological and ethnological research has revealed that, since antiquity, music had a syncretic nature. Music, dance, and poetry made up a single whole, aiming at expressing human feelings, sensations and perceptions through melody, rhythm, words, and gestures, and accompanying everyday activities that had various functions. Artistic syncretism is doubled by another structural principle – synaesthesia. The brain process that unifies senses and perceptions, synaesthesia is defined as the spontaneous association of several senses and sensations, in response to the action of a single stimulus. People with the so-called colorful hearing associate auditory reception with the perception of colorful images. Many artists had this ability that was reflected in their artistic creation. Initially the fusion of music and color was researched by theorists, who tried to create musical instruments that would be able to radiate colours during the musical interpretation. The syncretic and synaesthetic relationship between sound and image is individualized at the beginning of the twentieth century. Starting with the Dadaist and futuristic trends, artists seek and discover new forms of expression that unite the audible and the visual in a single form of representation. At present, the interaction between arts is seen as a fact, common also due to multimedia technology that allows the creation of synthetic, syncretic and synaesthetic ambiances, in which perception takes place at a multisensory level, changing the listener's one-sided perception. The art of sounds plays an essential role in syncretism and synaesthesia in music: in the first case, music participates in defining complex forms of artistic manifestation, and in the second, music generates sensations at the level of several senses. The listener benefits from new forms of artistic expression through which the transfer of the states and feelings of the artist to the listener occurs.

Upgrading Of Two Position Anti-skid Valve For Braking System Of Urban Rail Transit Vehicles

Based on the structural principle of the existing two-position anti-skid valve for urban rail vehicles, the valve has been modified to increase the pressure maintaining position based on the original only brake position and release position, so as to upgrade to the three-position anti-skid valve. As the pressure-maintaining position is added, the maximum braking force shall be kept as far as possible under the premise of anti-skid control of the train, so as to shorten the braking distance and ensure driving safety.

Expertenkommission Forschung und Innovation (EFI)*: Gesundheitswirtschaft in der digitalen Transformation

Abstract The healthcare industry comprises a complex system of stakeholders with different interests and needs. For the successful digital transformation of the healthcare industry, it is therefore essential to establish appropriate governance structures that take this complexity into account. To establish these structures, the Commission of Experts for Research and Innovation recommends the set-up of a roadmap clearly specifying the goals to be achieved, the milestones to reach and the critical aspects associated with them, as well as the responsible actors involved. Using the example of the Health Data Space – as a central element of the digital transformation of the healthcare industry – the Commission of Experts outlines the basic framework to illustrate the structural principles of roadmapping.

Prediction using multi-objective slime mould algorithm optimized support vector regression model

Different from the traditional neural network models based on empirical risk minimization principle, support vector regression (SVR) minimizes the upper limit of generalization error by the structural risk minimization principle. SVR is suitable for solving nonlinear, small-sample, high-dimensional modelling, and pattern recognition problems. However, the selection of hyperparameters of SVR can significantly affect the prediction accuracy and computational time. This paper proposes a method to optimize the SVR hyperparameters through an intelligent optimization algorithm, specifically multi-objective slime mould algorithm (MOSMA). MOSMA is a new multi-objective optimization algorithm with strong global search ability and fast convergence. The principle and calculation process of MOSMA are first described in detail. The analytical method for transforming the SVR hyperparameter optimization problem into a multi-objective problem is then presented. The process of optimizing two SVR hyperparameters (the penalty coefficient and radial basis function kernel parameter) based on MOSMA is described in steps. Meanwhile, the procedures of algorithm parameter setting, fitness function design, and population update are given. To investigate the characteristics and performance of MOSMA-SVR, two datasets are used to predict the vibration trend of the spindle of CNC milling machine in one and the maximum bending normal stress in the cutting process in the other. The performance of MOSMA-SVR is evaluated by multiple statistical indexes and compared with seven other prediction models (GA-SVR, PSO-SVR, ABC-SVR, GWO-SVR, SSA-SVR, SMA-SVR and MOWOA-SVR).

Comparative Analysis of Cantilever Retaining Wall with and without Column

Abstract: Retaining walls play a crucial role in civil engineering projects, providing stability to soil, preventing erosion, and mitigating landslides. To design and analyse these walls effectively, a profound understanding of soil mechanics, structural engineering principles, and various wall configurations is required. One notable configuration is the Cantilever Retaining Wall, which is known for its simplicity and effectiveness in resisting lateral earth pressures. However, for taller retaining walls, incorporating a column has shown potential in achieving greater cost-efficiency. This research aims to conduct a comprehensive analysis of cantilever retaining walls, comparing those with and without a column system. The study utilizes manual calculations, as well as software tools like STAAD Pro and Excel spreadsheets, for design optimization. Adherence to the guidelines specified in the Indian Standard IS 456:2000 for reinforced concrete structures ensures compliance with industry standards. The research involves a thorough examination and design of both the Cantilever Retaining Wall (CRw) and the Column Cantilever Retaining Wall (CCRw), considering a 35-meter span and heights ranging from 3 to 9 meters. Through a comprehensive evaluation of construction costs, this study concludes that the CCRw configuration offers superior costeffectiveness compared to the CRw configuration.