Mechanical Elements Research Articles

Benefit-Sharing Mechanism in Cross-Regional Agricultural Product Supply Chain: A Grounded Theory Approach

The accelerated development of economic globalization has given rise to the formation of supply chain networks for cross-regional agricultural products. However, the unequal rights and status of the partners and an imperfect benefit linkage mechanism have made it difficult to reasonably distribute and share benefits. Understanding how to establish a benefit-sharing mechanism among partners has been a popular topic in the industry, but thematic research and discussions are lacking in the academic community. Therefore, in this study, we utilized a grounded theory approach and selected five supply chain master enterprises with different supply chain systems as samples. We constructed a theoretical model of a benefit-sharing mechanism and systematically revealed the key elements and theoretical logic of benefit sharing. The results of this study showed that (1) the five elements of benefit creation, benefit integration, benefit distribution, benefit constraint, and benefit coordination have important impacts on benefit sharing in the supply chain; (2) the dimensions within these five elements are independent of each other, and these elements can be combined to demonstrate a common impact on benefit sharing. The dynamic interaction among the five elements constituted a self-regulating and self-optimizing cyclic system; (3) benefit integration and benefit distribution have a dynamic cyclic facilitating effect on benefit sharing. This study has refined the key elements of the benefit-sharing mechanism, and the results provide theoretical references for benefit sharing and in-depth collaboration among supply chain members.

Investigation of toxin genes and potential to control early shrimp mortality disease of chitosan on some Vibrio parahaemolyticus strains isolated from Mekong Delta

Acute Hepatopancreatic Necrosis Disease (AHPND) is a disease that induces mass early mortality in shrimp caused by Vibrio parahaemolyticus. This bacterium is capable of secreting biofilm - the main element in the host invasion mechanism and also protects V. parahaemolyticus from anti-bacterial agents, especially antibiotics. In this study, 03 strains of V. parahaemolyticus isolated from infected shrimp samples were investigated for toxin genes. They had the toxR gene and lacked tdh, trh and pPVA3-1 virulence plasmid genes. Chitosan was used to inhibit and destroy their biofilm biosynthesis in order to prevent AHPND. The minimum chitosan concentration inhibiting biofilm biosynthesis was 2 g/L. At 3 g/L, chitosan was capable of destroying 87.78 - 88.74% of the formed film. Biofilm analysis before and after treatment with chitosan showed that the EPS rate after treatment was reduced by 68-72.73% compared to that before treatment. The results demonstrated the potential of chitosan in the prevention of AHPND.

Evaluation of Reactor Laboratory Internet Services of Kartini Reactor Based on Regulation of the Minister of PANRB Number 14 of 2017

Kartini Reactor is one of Indonesia's research reactors that is used to learn nuclear technology. One of its services is the Internet Reactor Laboratory (IRL) with online Synchronous Learning-based implementation. To fulfill laws and regulations related to public services, meet the targets of BRIN agency work units, and evaluate to achieve excellent service, a survey is needed to assess the quality of IRL services in a Community Satisfaction Index (IKM) and Community Satisfaction Survey (SKM) using the guidelines of the Minister of PANRB Regulation Number 14 of 2017. The data collection method uses an e-questionnaire distributed to service users, which is then analyzed quantitatively. At the same time, the follow-up improvements use qualitative methods with interviews and observations. The survey results are used to evaluate and improve services to provide excellent service and fulfill community expectations and demands. The results of the quantitative analysis obtained that the results of the service IKM were 3.50 (maximum scale 4.00), and the service SKM value was 87.48 (maximum scale 100), which is included in the category of service quality B, which indicates the performance of the service unit is Good. As a further evaluation for service improvement, three service element values with the lowest values were taken: the system, mechanism, and procedure elements, service time elements, and service product specification elements. The practicum module will be classified based on the difficulty level of the system, mechanism, and procedure. In the service time element, the instructor will start and end the practicum on time, the Zoom admin will act as a time monitor, and students are directed to be present 5 minutes before the practicum. In the service specification product element, untidy practicum modules and unclear PowerPoint visualizations will be improved through synchronization of semester learning plans (RPS) with universities, adjustment of modules according to learning outcomes, standardization of visualization, and instructor training. Keywords: Internet Reactor Laboratory (IRL), Community Satisfaction Index (CSI), Community Satisfaction Survey (CSS), evaluation of practicum services

Magnetically programmed diffractive robotics.

Microscopic robots with features comparable with the wavelength of light offer new ways of probing the microscopic world and controlling light at the microscale. We introduce a new class of magnetically controlled microscopic robots (microbots) that operate at the visible-light diffraction limit, which we term diffractive robots. We combined nanometer-thick mechanical membranes, programmable nanomagnets, and diffractive optical elements to create untethered microbots small enough to diffract visible light and flexible enough to undergo complex reconfigurations in millitesla-scale magnetic fields. We demonstrated their applications, including subdiffractive imaging by using a variant of structured illumination microscopy, tunable diffractive optical elements for beam steering and focusing, and force sensing with piconewton sensitivity.

Построение моделей и статистическая оценка параметров надежности судовых технических средств

A method is proposed to solve the problems that arise when analyzing information obtained from various sources, it is necessary to combine it in a complex of coordinated stochastic models. For most processes of mechanical destruction of machine parts, such as wear, fatigue volumetric or surface destruction, corrosion, etc., the monotony of the implementation of degradation processes leading to failures is characteristic. The scheme of resource allocation formation is given, which corresponds to the main types of mechanical failures occurring in the elements of ship mechanisms. The diagram illustrates a fairly general case when, with an increase in the operating time of an element, its resistance to destruction decreases monotonously, and the damage parameter also increases monotonously. Based on the use of generalized distributions, it is possible to obtain several variants of complexes of mechanical reliability models in which the resource allocation has a fairly simple analytical form. When modeling degradation processes, the DM distribution can be obtained as a special case of distributions and without using the Markov model of random processes. Only the mixing condition of the process implementations is essential. Obtaining various types of operating time distributions before the parameter reaches a fixed level using the obtained dependencies is not associated with any assumptions about the nature of individual implementations of the degradation process, except for their monotony. From the point of view of practical application, the distribution under consideration, obtained on the basis of Weibull’s law, has the advantage of universality, since, unlike the normal law, it can also be used for values of the coefficient of variation significantly exceeding 0.3.

A numerical simulation of a novel self-powered implantable respiration sensor based on a triboelectric nanogenerator for medical applications

Abstract The breathing rate is utilized as a reliable indicator in many cases to predict and diagnose respiratory diseases as well as the respiratory dysfunction caused by diseases such as the cystic fibrosis. Therefore, in this study, a self-powered implantable respiration sensor based on a contact-separation mode triboelectric nanogenerator (TENG) was designed to monitor the respiratory rates by sensing the variation of the diaphragm muscle. For this purpose, a polytetrafluoroethylene film with a thickness of 160 μm and a nylon film with a thickness of 180 μm are employed as the negative and positive triboelectric materials. Two copper layer each with a thickness of 100 μm are placed on the outer surfaces of the triboelectric layers as the conducting electrodes. In order to uniformly deform the moving plate of the TENG, it is rigidly attached to the center of the diaphragm through a silicon mechanical coupling element with dimensions of 80 x 80 μm2. The pressure caused by breathing on the diaphragm muscle, which is in the range of 266-666 Pa, is applied to the center of the device diaphragm. The effect of various parameters including external pressure, frequency and surface charge density on the output performance of the device is also investigated. It is evident that higher external pressure results in intensive deformations of the moving plate of the TENG, leading to a more significant energy conversion efficiency of the device. Similarly, increasing the surface charge density causes an increase in all electrical output parameters. Moreover, the device achieves an output power of 0.209 nW at a load resistance of 20 GΩ by applying a pressure of 666 Pa at a frequency of 0.24 Hz. All the results demonstrate the potential of the new proposed sensor for detecting and monitoring real-time respiratory rates with high sensitivity and clinical applications.

Transformation of the Constitutional Model of Public Formations in the Republic of Belarus

The transformation of the constitutional model of public formations in the conditions of formation and development of the Republic of Belarus is considered as a formal legal objectification of the relevant principles and categorical and conceptual apparatus within the framework of the dynamics of constitutional regulation caused by socio-political and other factors, it provides for a transition from the perception of public formations as an element of the party-state mechanism to the recognition of their independence and functional diversity with the presence of political priority in the intended purpose. It is noted that at the present stage, the constitutional model of public formations in the Republic of Belarus is being transformed within the framework of the development of the constitutional foundations of democracy and civil society, the consolidation of the ideology of the Belarusian state as a constitutional dominant, the revision of the purpose and differentiation. Proposals are being made to develop the relevant constitutional legislation in the Republic of Belarus.

A New Concept for Cervical Expansion Screws Using Shape Memory Alloy: A Feasibility Study.

In general, sufficient anchoring of screws in the bone material ensures the intended primary stability. Shape memory materials offer the option of using temperature-associated deformation energy in a targeted manner to compensate the special situation of osteoporotic bones or the potential lack of anchoring. An expansion screw was developed for these purposes. Using finite element analysis (FEA), the variability of screw configuration and actuator was assessed from shape memory. In particular, the dimensioning of the screw slot, the actuator length, and the actuator diameter as well as the angle of attack in relation to the intended force development were considered. As a result of the FEA, a special configuration of expansion screw and shape memory element could be found. Accordingly, with an optimal screw diameter of 4 mm, an actuator diameter of 0.8 mm, a screw slot of 7.8 mm in length, and an angle of attack of 25 degrees, the best compromise between individual components and high efficiency in favor of maximum strength can be predicted. Shape memory material offers the possibility of using completely new forms of power development. By skillfully modifying the mechanical and shape memory elements, their interaction results in a calculated development of force in favor of a high primary stability of the screw material used. Activation by means of body temperature is a very elegant way of initializing the intended locking and screw strength.

Optimizing university-industry collaboration mechanisms for engineering talent development in the nuclear power sector

In the context of the ongoing scientific and technological revolution and industrial transformation, the primary goal of engineering education is to develop innovative and skilled professionals who can address the evolving needs of economic and social development. The success of this endeavor is contingent upon the effectiveness of university-industry collaboration in creating robust talent cultivation models. This study identifies and constructs key elements of a safeguard mechanism for such collaborations, including laws, regulations, management systems, and operational frameworks. A survey was conducted among university and industry leaders engaged in cooperative projects within the nuclear power sector, revealing significant insights into the current state and deficiencies of existing mechanisms. Based on these findings, the study proposes targeted strategies and recommendations for enhancing the effectiveness of these collaboration mechanisms.

Modified Use of the Component Method to Get More Realistic Force Distribution in Joints of Steel Structures

According to the EN 1993-1-8 Standard, the moment resistance of end-plated connections can be calculated with the use of the component method. In this, a pair-of-force defines the moment resistance. The magnitude and the location of the compression force can be accurately identified. The tension force part is usually the resultant of parallel forces appearing in line with the bolt rows. Following the rules of manual calculation and using a mechanical finite element model, where each component is modelled with spring elements, in some—easily identifiable—cases, leads to different force distribution. The simplifications defined in the Standard provide a longer arm for the same force, and because of this, larger moment resistance at the expense of safety. In this work, an alternative calculation method will be presented that provides the same force values in each bolt row, as the mechanical model of the connection, without constructing the finite element model.

Development of a mechanism for managing the quality of customs services at the post-customs control stage

Subject. The article discusses the need for methodological support and technological justification of assessment and improvement of the customs services quality at the post-customs control stage. Objectives. The study aims to develop a comprehensive methodology to evaluate the effectiveness of structural units and the quality of rendered services as a basic element of the management mechanism. Methods. The study rests on the system methodology. We decomposed the mechanism of customs services quality management, and developed its morphological model during the analysis of individual components of the mechanism. Results. We developed a mechanism to manage the quality of services provided at the stage of post-customs control. It is divided into operational and strategic levels of management decision-making. Furthermore, we disclosed individual elements of the quality management mechanism, identified the main activities of the post-control units, within which key performance indicators are evaluated. As a pragmatic example, we developed a matrix for calculating performance indicators for one of the main areas of activity. Conclusions. The further direction of scientific research should be a model of the consumer of customs services, which determines the economic essence of solving the problem of developing the activities of the Federal Customs Service of Russia at the stage of post-customs control.

Global buckling and residual capacities of circular recycled aggregate concrete-filled stainless steel tube (RACFSST) columns after exposure to fire

The post-fire flexural buckling behaviour and capacities of circular recycled aggregate concrete-filled stainless steel tube (RACFSST) columns are studied in this paper, underpinned by testing and numerical modelling. A testing programme was firstly conducted on twelve column specimens designed with three recycled coarse aggregate replacement ratios (0%, 35% and 70%), including nine column specimens after exposure to the ISO 834 standard fire for 15 min, 30 min and 45 min and three reference column specimens at ambient temperature. The test failure modes, load–mid-height lateral deflection curves and failure loads were reported in detail. The influences of heating durations and recycled coarse aggregate replacement ratios on failure loads and mid-height lateral deflections at failure loads of circular RACFSST column specimens were discussed and their lateral deflection distributions were analysed. The testing programme was followed by a numerical modelling programme, where thermal and mechanical finite element models were developed to repeat the experimental results and afterwards used to carry out parametric studies to generate a numerical data pool over a wide range of cross-section dimensions and member lengths. Based on the test and numerical data, the relevant design rules for circular natural aggregate concrete-filled carbon steel tube columns at ambient temperature, as specified in the European code, Australian/New Zealand standard and American specification, were evaluated, using post-fire material properties, for their applicability to circular RACFSST columns after exposure to fire. It was revealed from the evaluation results that the three design codes led to overall acceptable levels of accuracy and consistency in predicting post-fire flexural buckling capacities of circular RACFSST columns, but with some unsafe predictions.

Development of a computational system to design a helical spring

AbstractSprings are the most basic mechanical elements used in transmission mechanisms. The rapid development of the computer and cellular industry has encouraged spring manufacturers to develop the industry to produce very small springs. Most computer-aided design programs for mechanical parts provide the possibility of designing these parts, as these programs include different types of decisions. All these decisions require coordinates for geometric data as well as metadata. The paper aims to develop software programs to design and analyze springs as one of the most significant mechanical elements used. This paper aims to develop a design software of a helical spring system, where this software is built using a computer program in the language of Visual Basic Version 5. When the user enters data into the system, the system will perform a series of complex calculations in the system, then provide a detailed report on all the engineering dimensions of the spring, and test its efficiency. The output of the software shows the required spring wire parameters. The software was tested with test data from the open literature, and the required wire spring parameters were obtained.

Complexion-induced Cu2+ coordinated phase separation PBI membrane for lithium metal batteries

The uncontrolled dendritic lithium production issues and the highly reactive behavior of lithium with electrolytes has limited use of lithium metal batteries. Herein, we utilized a straightforward method of the Complexion-Induced Phase Separation (CIPS) to fabricate a Cu2+ coordinated polybenzimidazole (PBI) membrane for a lithium metal battery. CIPS offer improved control over the structure and composition of the membrane, potentially leading to improved selectivity in ion transport, enhancing the safety and longevity of the battery. The formation mechanism and influencing elements of PBI-Cu are analyzed through experimental analysis and density functional theory calculations (DFT). The PBI-Cu membrane is effective in facilitating reversible lithium stripping and plating processes, suppressing dendrite formation, and promoting stable long-term cycling. Notably, the PBI-Cu cell demonstrated stable cycling conditions for over 200 h at a very high current density of 4 mA cm−2. The impressive rate performance was also confirmed during Li//LiFePO4 full cell operation, where it maintained a stable capacity of 120 mAh g−1 for more than 300 cycles. This research provides an in-depth insight into membrane design and paves the way for its application in various other energy-related technologies.

The Phenomenon of Psychological Warfare in the Era of the Sun King

The article examines the main aspects of the design of the psychofield (psychological landscape) of the French monarchy in the Early Modern era in the context of the formation of absolutism (as a geopolitical doctrine) in the context of the «military revolution» in Europe. The author examines the transformations of mass consciousness within the framework of the phenomenon of the «mental revolution», which determined the emergence of new forms of legitimization of social ties in the context of the formation of innovative systems of constructing loyalties that replace, absorb or conflict with alternative identities within the framework of a new state-building, in an imperial situation. The author touches upon the problem of the formation of a new «psychoparadigma», which determines the course of a number of social and political processes that determined the formation of court society as an element of the state mechanism. A direct reflection of this process was a complex of political, psychological and socio-cultural transformations, which, following N. Henschel, we interpret as the «myth of absolutism», which gave rise to a whole complex of innovations in the development of mass consciousness, which was most manifested, first of all, in the development of military affairs. A direct reflection of this phenomenon was, among other things, the active use of the practice of «psychological warfare» in the campaigns of the «Sun King», which is associated with a rethinking of the degat principle characteristic of the Middle Ages – waging a devastating war.

A piezoelectric human motion energy harvester with stress amplification mechanism

The kinetic energy is rich in human walking, which may be exploited to provide sustainable energy for portable and miniaturized devices by properly design of the energy harvester. In order to effectively amplify the actual force on the piezoelectric material upon the external load, a beam-shaped piezoelectric energy harvester (PEH) is designed. The PEH is prepared by embedding poly(vinylidene fluoride) (PVDF) piezoelectric strips into the compression zone of the beam. The underlying mechanism is discussed via mechanical theoretical modeling and finite element simulation. It is demonstrated that the actual integrated force on the piezoelectric film of PVDF is about 31.7 times that of the external force applied on the beam’s mid-span. The study would pave the way for force amplification mechanism in designing PEHs and holds promises for portable device applications.

Coupled thermal-electrical–mechanical characteristics of lightning damage in woven composite honeycomb sandwich structures

In this study, lightning strike damage of woven carbon fibre-reinforced polymer laminates (W-CFRPs) and woven composite honeycomb sandwich panels (W-CHSPs) are simulated using the proposed sequential thermal-electrical–mechanical finite element (FE) coupling model incorporating dielectric breakdown of materials. Surface current with an amplitude of 200 kA and corresponding lightning shockwave overpressure were applied on each composite. The FE model coupled with LaRC05 criterion was used to study the failure behaviours of intralaminar damage and interlaminar delamination of the W-CFRPs and W-CHSPs. A series of lightning strike tests were performed to validate the FE model. Detailed lightning damage assessments and mechanisms were characterized by a combination of visual inspection, image processing, ultrasonic scanning and micro computed tomography (Micro-CT) and showed good agreements with the FE-predicted results. It can be concluded that shockwave overpressure significantly impacts lightning-induced damages, thereby supporting the effectiveness of the newly proposed sequential thermal-electrical–mechanical coupling model, which demonstrates improved predictive accuracy.

Forms of Representation of Military Culture in Computer Games

The purpose of this article is to identify the forms of representation of military culture in computer games. In the course of the research, six types of interpretations of military culture were presented on the basis of a systematic approach, which made it possible to formulate a more general, broad concept that served as a basis for the subsequent discovery of its aspects and representations in computer games developed since the 2000s. The representation of aspects of military culture in games is reflected in four forms of representation: through game theme, individual game elements and stories, game genre, and game mechanics. The first one takes into account that the military theme is revealed in computer games in several forms of relation to reality: military-historical games; games thematically related to the modern army and modern military conflicts; games modelling military conflicts of the near future; fantasy games representing the army or armed forces of the distant future; fantasy games. The second demonstrates that mechanical elements and plot moves related to military culture can be present in games of almost all genres. The third defines genres related to military culture, the division of which is along the lines of personalized participation in military actions/simulation of a certain command and operation level, and each of them has its own aspects. The distinctive feature of the above forms is a limited representation of military culture, subjective focus on individual aspects. The fourth form of representation assumes a positive forecast of the development of computer games about military culture. It is expected that a simulator of everyday activities of servicemen will appear, which would make it possible to take a new look at military games and reflect the requirements of Russian legislation in the field of defense. This will help, among other things, to shape the directions of the state cultural policy for the development and preservation of the spiritual and moral foundations and traditional values of Russian culture embodied in modern forms and genres of art.

Риск-ориентированный анализ безопасности эксплуатации транспортных средств на основе использования инструментов цифровизации

The issue of occupational safety during activities of transportation in conditions of intensified impact of factors of the external environment is considered. The constituent elements of the occupational safety mechanism for the implementation of transportation processes have been analyzed. Based on the studies of injury rate in railway transport, the key causes of occupational safety decrease in contemporary geopolitical conditions have been detected, and the options for the improvement of occupational safety considering the implementation of digital technologies enabling the accumulation, registration, structuring, and analysis of large amounts of data have been considered. It is crucial for the use of blockchain technology to register the information about the movement of a vehicle without the possibility of its correction and monitor the condition of the transport infrastructure. A hybrid approach has been proposed for the development of the occupational safety mechanism based on the implementation of the «force field analysis» approach implying the identification and assessment of the impact of factors of the external environment that can directly or indirectly affect occupational safety in the transportation sphere. Using this approach enables the consideration of the riskiness of the transportation process based on the analysis of factors facilitating the improvement of life safety and factors hampering the implementation of innovations in the sphere of movement of vehicles. Based on the studies, a model of risk-oriented analysis of the safety of vehicle operation that characterizes the level of occupational safety when assessing emerging risks during vehicle operation, oriented to the systematization of analysis of statistical data, has been presented. The options to improve the occupational safety mechanism based on the monitoring of potentially hazardous transportation risks generated by changing factors of the external environment and the assessment of consequences of risks have been proposed to develop measures of risk prevention.

Impacts of the Thermocline Feedback Uncertainty on El Niño Simulations in the Tropical Pacific

AbstractAs a key dynamic element of the Bjerknes feedback mechanism, the thermocline effect (TE) is critically important to El Niño modeling. In this study, the potential influence of TE‐related parametric uncertainties on El Niño is investigated using the conditional nonlinear optimal parametric perturbation (CNOP) method based on an intermediate coupled model (ICM). The optimal perturbation of the TE‐related parameter (OTEP), which substantially affects El Niño simulations, is estimated through the CNOP approach. Results reveal that the El Niño simulation is highly sensitive to the TE uncertainty in the eastern equatorial Pacific, with OTEP‐induced simulation errors demonstrating an El Niño‐like growth trend. On one hand, as indicated by the simulated El Niño intensity, the uncertainty in the TE in the eastern region can easily affect the strength of the Bjerknes feedback‐related thermocline effect and atmospheric circulation. On the other hand, the enhanced TE is highly favored to accelerate the growth of the SST error due to the air–sea interaction, thus severely affecting the El Niño simulations. Therefore, adequately representing the TE in the equatorial eastern Pacific is emphasized for effectively improving El Niño simulations.