System Equipment Research Articles

Summer period analysis of the rotary desiccant - hybrid cooling system combined with solid oxide fuel cells using human waste fuel

This paper proposes and simulates a desiccant air cooling system integrated with a vapor compression cooling unit and a heat recovery unit for an office building in Çanakkale, Turkey, during the summer season. The required electrical energy for equipment of the proposed system is supplied by an Solid Oxide Fuel Cells (SOFC) unit using human waste as fuel. Moreover, some of the waste heat generated by the SOFC is used to regenerate the desiccant wheel. The simulation also includes the effects of three different refrigerants for the vapor compression cooling unit. Among the refrigerants, the highest electrical COP was obtained for the system using R1234ze(Z), which is 3.14% and 2.40% higher than the systems using R717 and R1233zd(E), respectively. Additionally, the system using R1234ze(Z) achieved electrical savings of 9.97% and 9.23% compared to the other systems. These electrical savings resulted in fuel savings of 1.19% and 0.90% for R1234ze(Z) compared to R717 and R1233zd(E), respectively. During the summer season, the electricity production from the existing SOFC unit met 82.00% of the total electricity consumption of the desiccant hybrid cooling system. Furthermore, a difference of 3984.56 kWh in primary energy consumption was identified between the desiccant hybrid cooling systems operating with the SOFC and without the SOFC during the summer season.

Multiphysics simulation of a high power coaxial-to-waveguide transition

Coaxial-to-waveguide transitions are widely used in high-power microwave paths. Coupling elements in the form of capacitive probes and current loops, traditionally used in coaxial-waveguide transitions, often lead to a decrease in their dielectric strength. This problem is especially acute in the case of rectangular waveguide with reduced-height, which are widely used due to their small mass and dimensions. This paper presents the results of the development and multiphysics simulation of a C-band coaxial-to-waveguide capacitive-type transition designed to operate at high power levels, including under conditions of low atmospheric pressure. A thermal analysis was carried out and the conditions for the occurrence of multipactor and corona breakdowns were investigated. The developed coaxial-to-waveguide transition can be used in radio-electronic equipment of terrestrial and space communication systems. The obtained results of development and research can be used in the design of transmission line matching devices for on-board radio-electronic systems.

Research on the Application of Digital Twin Technology in Equipment Maintenance

Digital twin technology is to make full use of the data such as physical model, sensor update, running history, integrate the multi-subject multi-physical quantity, multi-scale, multi-probability simulation process, complete the mapping in virtual space, thus reflect the whole life cycle process of the corresponding entity equipment. In this paper, the digital twin of a certain type of equipment system is studied to realize the operation condition monitoring, fault intelligent diagnosis and so on, so as to improve the maintenance efficiency and effect of the equipment.

One-Year Surveillance of a Patient Cohort’s Lung Ultrasonography Findings Post Mild-Moderate COVID-19 Infection

Objective: Lung involvement due to COVID-19 infection relates to patient clinical outcomes. However, little evidence exists on whether an abnormal lung sonogram, during an initial outpatient infection, may signal an abnormal immunologic response and lasting abnormalities. The aim of this study was to observe whether high-risk outpatients, previously infected with SARS CoV-2 and found to have an initial abnormal lung sonogram, had persistent diagnostic findings at a 1-year re-examination. Materials and Methods: A prospective longitudinal cohort study was performed, based on a prior study completed in January 2022 wherein 55/201 (27%) of consecutive outpatients infected with SARS-CoV-2 received therapy at an outpatient monoclonal antibody clinic and had presented with an abnormal lung ultrasound containing at least 3 apical lung B-line artifacts (LUS+). One year later, the original 55 LUS+ patients were contacted for re-examination; as a result, 14 LUS+ patients consented to a repeat LUS tospecifically recheck the apical area of the lungs for persistent B-line artifacts. The same ultrasound equipment system and imaging methodology were used for this cohort of patients. Additional data was collected regarding COVID-19 test-positive re-infection, persistent pulmonary symptoms during the past year, and COVID-19 vaccination status. Results: Of the 14 LUS+ patients, the mean cohort age was 63 ± 9 years, of which 71% were men. Over the ensuing year, 43% had persistent symptoms, 71% had updated vaccination, and 36% had a self-reported re-infection. The re-infection was reported to have occurred a median of 7 months after the initial infection. The cohort was sub-divided into those with persistent LUS+ compared to those that reverted to a normal scan. The mean age was 69 ± 10 years among those LUS+ compared to 56 ± 8 years in the normalized group. The body mass index (BMI) was 32 kg/m2 in those LUS+ compared to 27 kg/m2 in the normalized group. The cohort has 6 men and 2 women in the LUS+ group compared to 4 men and 2 women in the normalized group. One LUS+ patient out of eight reportedly had been reinfected compared to four normalized patients out of six stated being reinfected. Three LUS+ patients out of eight reported having persistent symptoms compared to three normalized patients out of six complaining of continued COVID-19 symptoms. Conclusion: Based on the 1-year repeated LUS, for this cohort, there was a high prevalence of persistent symptoms and lung abnormalities, in those who had mild-moderate outpatient COVID-19 and received monoclonal antibody therapy. The longitudinal data collection on this cohort of COVID-19 positive outpatients may suggest that individual immune responses or viral virulence factors may play a role in B-line persistence. Certainly, future LUS results may be confounded by a previous COVID-19 infection.

The Management of Nurturing, Child Care for Children Aged 18 to 36 Months Using a Participatory Approach: A Case Study of Preschools in Thanh Hoa Province

In the education system, each level of education has its own characteristics and must be given special attention, including preschool education, which is the first stage of personality formation and understanding of each person, so it must be considered a key educational task, the top priority in the national education system. Through going to school, children will be comprehensively developed in terms of physical, intellectual, emotional, aesthetic, and personality formation. Currently, with the economic development situation, the need for comprehensive development for children is also more focused not only by parents but also in each school. This has become the goal to develop and perfect the system of equipment, facilities, and capacity of teachers and the school's management team. The study uses a participatory approach based on the management participation of management groups in particular and components in education in general, thereby assessing the current status of management of child care and nurturing activities. The research results also show that the management of preschools still has many shortcomings, including the differences in economic characteristics of each region, the quality of the teaching staff, facilities and equipment, etc. There are many issues that still need attention due to the uneven development between regions and areas. Therefore, in order for activities to develop more and more, it is still necessary to pay attention to investment and research the current

Retraction Note: Application of interactive multimedia based on optical imaging equipment in digital calligraphy information processing system

Retraction Note: Application of interactive multimedia based on optical imaging equipment in digital calligraphy information processing system

Application of SHAP and Multi-Agent Approach for Short-Term Forecast of Power Consumption of Gas Industry Enterprises

Currently, machine learning methods are widely applied in the power industry to solve various tasks, including short-term power consumption forecasting. However, the lack of interpretability of machine learning methods can lead to their incorrect use, potentially resulting in electrical system instability or equipment failures. This article addresses the task of short-term power consumption forecasting, one of the tasks of enhancing the energy efficiency of gas industry enterprises. In order to reduce the risks of making incorrect decisions based on the results of short-term power consumption forecasts made by machine learning methods, the SHapley Additive exPlanations method was proposed. Additionally, the application of a multi-agent approach for the decomposition of production processes using self-generation agents, energy storage agents, and consumption agents was demonstrated. It can enable the safe operation of critical infrastructure, for instance, adjusting the operation modes of self-generation units and energy-storage systems, optimizing the power consumption schedule, and reducing electricity and power costs. A comparative analysis of various algorithms for constructing decision tree ensembles was conducted to forecast power consumption by gas industry enterprises with different numbers of categorical features. The experiments demonstrated that using the developed method and production process factors reduced the MAE from 105.00 kWh (MAPE of 16.81%), obtained through expert forecasting, to 15.52 kWh (3.44%). Examples were provided of how the use of SHapley Additive exPlanation can increase the safety of the electrical system management of gas industry enterprises by improving experts’ confidence in the results of the information system.

Nondestructively Determining Soluble Solids Content of Blueberries Using Reflection Hyperspectral Imaging Technique

Effectively detecting the quality of blueberries is crucial for ensuring that high-quality products are supplied to the fresh market. This study developed a nondestructive method for determining the soluble solids content (SSC) of blueberry fruit by using a near-infrared hyperspectral imaging technique. The reflection hyperspectral images in the 900–1700 nm waveband range were collected from 480 fresh blueberry samples. An image analysis pipeline was developed to extract the spectrums of blueberries from the hyperspectral images. A regression model for quantifying SSC values was successfully established based on the full range of wavebands, achieving the highest RP2 of 0.8655 and the lowest RMSEP value of 0.4431 °Brix. Furthermore, three variable selection methods, namely the Successive Projections Algorithm (SPA), interval PLS (iPLS), and Genetic Algorithm (GA), were utilized to identify the feature wavebands for modeling. The models calibrated from feature wavebands generated an RMSEP of 0.4643 °Brix, 0.4791 °Brix, and 0.4764 °Brix, as well as the RP2 of 0.8507, 0.8397, and 0.8420 for SPA, iPLS, and GA, respectively. Furthermore, a pseudo-color distribution diagram of the SSC values within blueberries was successfully generated based on established models. This study demonstrated a novel approach for blueberry quality detection and inspection by jointly using hyperspectral imaging and machine learning methodologies. It can serve as a valuable reference for the development of grading equipment systems and portable testing devices for fruit quality assurance.

Significantly Enhanced Corona Resistance of Epoxy Composite by Incorporation with Functionalized Graphene Oxide

Enhancing the corona resistance of epoxy resin (EP) is crucial for ensuring the reliable operation of electrical equipment and power systems, and the incorporation of inorganic nanofillers into epoxy resin has shown significant potential in achieving this. In this study, functionalized graphene oxide (KHGO) was synthesized via a sol-gel method to enhance the corona resistance of EP with electrochemical impedance spectroscopy (EIS) used to assess the properties of KHGO/EP composites. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) verified the successful grafting of epoxy groups onto the GO surface. The thermal conductivity and stability of the KHGO/EP composite initially increased with KHGO content but declined when the content exceeded 1.2 wt.%. Positron annihilation lifetime spectroscopy (PALS) indicated that KHGO improved interfacial compatibility with EP compared to GO, with agglomeration occurring when KHGO content exceeded a threshold value (1.2 wt.%). EIS analysis revealed that the corona resistance of the KHGO/EP composite was optimal at a filler content of 0.9 wt.%. After corona treatment, the saturation water uptake of the 0.9 wt.% KHGO/EP composite decreased by 15% compared to pure EP with its porosity reduced to just 1/40th of that of pure EP. This study underscores that well-dispersed KHGO/EP composite exhibits excellent corona resistance property suggesting the potential for industrial applications in high-voltage equipment insulation.

Resonance Suppression Method Based on Hybrid Damping Linear Active Disturbance Rejection Control for Multi-Parallel Converters

The parallel operation of multiple LCL-type converters will result in a deviation of the resonant frequency and resonance phenomena. The occurrence of harmonic resonance can cause problems such as an increase in harmonic voltage and current. This can lead to the malfunction of relay protection and automatic devices, causing damage to system equipment. In severe cases, it can cause accidents and threaten the safe operation of the power system. A hybrid damping active disturbance rejection control (HD-ADRC) method is proposed in this paper to suppress the harmonic resonance of parallel LCL-type converters. First, a third-order linear disturbance rejection controller (LADRC) including the linear extended-state observer and the error-feedback control rate is designed based on LCL-type converter model analysis. The proposed method considers the resonance couplings caused by both internal and external disturbances as the total disturbance, thus improving the anti-disturbance capabilities as well as the operational stability of converters in parallel. Then, a hybrid damping control is proposed to reconstruct the damping characteristics of converters to suppress the parallel resonance spike and reduce the resonance frequency offset. And the parameter selection of the control system is optimized through a stability analysis of the tracking performance and anti-disturbance performance of the HD-ADRC controller. Finally, all the theoretical considerations are verified by simulation and experimental results based on the Matlab/Simulink 2018B and dSpace platform. The simulation and experimental results show that the PI controller gives a THD of 5.33%, which is reduced to 4.66% by employing the HD-LADRC, indicating an improved decoupling between the converters working in parallel with the proposed control scheme.

Maintenance Tasks for 20 Kv Medium-Voltage Switchgear Based on Technical Judgment Experience and Manufacturer

A 20 kV medium-voltage switchgear is an important equipment in the electricity system that distributes electricity generated by the 20 kV electric power generator to electricity users. Calor Emag, Merlin Gerin, Alsthom, Fuji, AEG, Schneider, Meidensha, Goldstar, Modalek, Areva, and Siemens are among the companies that make products. This study describes a method for maintaining 20 kV medium-voltage switchgear, an essential equipment in the electricity system. In less technical terms, the failure rate is high at the beginning of an asset's life, which follows the curve of the bathtub. However, the failure rate quickly declines as we identify and discard defective components and eliminate early sources of potential failures, such as installation errors. This study introduces a novel approach by examining the relationship between maintenance tasks, which are based on technical judgment and experiences, and the maintenance tasks provided by the manufacturer for 20 kV medium voltage switchgear. The goal is to develop and deliver the most effective maintenance method for 20 kV medium voltage switchgear, to prevent malfunctions or even catastrophic explosions, while maintaining the lowest possible maintenance costs. Total use of labor over 2 years (24 months) for daily, monthly, 3 monthly, and 2 yearly is 3554-man hours (MH). It provides a comprehensive approach to preventing malfunctions and explosions, resulting in optimal maintenance costs and performance.

The Security and Protection System of Electromechanical Equipment in Smart Campus using the Improved Data Mining Algorithm

In order to improve the maintenance and management efficiency of campus electromechanical equipment and reduce or even avoid the safety risks brought by campus electromechanical equipment, this work uses the data mining algorithm to design the security and protection system of campus electromechanical equipment. First, this work constructs the campus electromechanical equipment classification model using the Bayesian algorithm of data mining algorithm and designs a simulation experiment to verify the effect of the classification model. Then, the security and protection system for the campus electromechanical equipment is designed. It includes the system business process, system function design, system core module’s function design and system implementation. Finally, a simulation experiment is designed to verify the system’s performance. The results show that: (1) Bayesian algorithm is superior to the K-Nearest Neighbor (KNN) algorithm in both classification effect and running time. (2) When the browser concurrency in the system increases, the server processor and memory usage also increases, but the value meets the expected requirements. It shows that the system has a certain browser concurrency-bearing capacity. Moreover, as the browser concurrency of the system increases, the response time of the test also increases, but the value meets the expected requirements. This work aims to improve the maintenance efficiency of campus electromechanical equipment and provide a reference for the safety protection work of electromechanical equipment in other enterprises or units.

Certification considerations and sound field simulation of civil aircraft cabin passenger address

Abstract In the design of a civil aircraft cabin passenger address system, it is quite necessary and very important to sufficient consider and demonstrate the system design architecture, equipment selection and arrangement to ensure that the system sound quality complies with the requirements of CCAR25.1423(c). In the design phase, the certification considerations of the passenger address system should be researched in advance to comply with CCAR25.1423(c). The cabin sound field distribution and STI of the civil aircraft cabin passenger address system should be simulated through professional tools to predict, demonstrate and judge the sound quality before the system preliminary design review (PDR). In this paper, the certification considerations of passenger address are developed and elaborated from the system equipment arrangement, automatic gain design, and inhibit method of the Larsen effect. Based on two loudspeaker arrangement options, the cabin sound field distribution and STI of the passenger address are simulated to indicate its compliance with CCAR 25.1423(c) from the proposal design level theoretically.

A Novel Method for Tailoring the Electromagnetic Radiation Emission Limits of Equipment in Complex System

A Novel Method for Tailoring the Electromagnetic Radiation Emission Limits of Equipment in Complex System

Reliability evaluation of direct current gathering system in onshore wind farm based on reliability block diagram-sequential monte carlo

The full DC wind power generation system has effectively overcome the harmonic resonance, reactive power transmission, and other problems of the traditional AC wind power system, which has broad prospects for development. As a key component of the mentioned system, the reliability of the collection system is critical to the safe and stable operation of the entire onshore wind farm. Firstly, this paper investigates the key equipment and topology of the onshore wind farm DC collection system. Secondly, considering both the internal components and external environment of the wind farm, a component outage probability model based on weather factors is constructed to provide accurate data for the reliability evaluation of the DC collection system of the wind farm. The Reliability Block Diagram is used to analyze the internal logical connection of different topologies of onshore wind farm DC collection systems in detail. Then, a reliability evaluation method of an onshore full DC wind farm collection system based on Reliability Block Diagram-Sequential Monte Carlo is proposed. Finally, a 50 MW onshore wind farm is studied as a sample to compare and analyze the assessment results of the reliability of different collection system topologies. The results show that the reliability of the DC collection system of onshore wind farms has significant advantages.

Poisonous Workplaces: What Workers Faced in British Chemical Weapons Factories.

Soldiers were not the only victims of chemical warfare in the twentieth century; the workers who produced these weapons also risked injury and death. Focusing on British chemical weapons factories during both world wars, this article advances our understanding of the human costs not only of war but also of the preparation for war. Technologies such as physical barriers, ventilation systems, protective equipment, and detection systems mitigated some hazards to workers, but financial constraints, wartime pressures, and limited knowledge of the damage caused by prolonged exposure to low levels of chemical weapons resulted in serious damage to workers' bodies.

Design of intelligent remote monitoring and diagnosis system for equipment

Design of intelligent remote monitoring and diagnosis system for equipment

Analysis of The EwacsPro Auto Dispatch System in XYZ Company Using Technology Readiness Level (TRL) and Technology Acceptance Model 2 (TAM2) Adoption

Fleet Management System (FMS) is a system that quite good to manage the haul cycle and can be useful for reducing the idle time of the conveyance. The development of an FMS with an Auto Dispatch System (ADS) that utilizes digital information technology can make management easier. ADS is the system which has assignment logic systems for transport equipment, either directly suggesting to the operator through computerized systems or through dispatchers. XYZ Company developed its own ADS, called Early Warning & Control System Pro (EwacsPro), which has been tested on 1 of 4 total pits they have in ABC jobsite, using the LTE Communication network, which is the first in Indonesia. The problem behind this research is that the system has never been tested for readiness. This research aims to analyze, evaluate and explore the level of readiness of the EwacsPro system using the Technology Readiness Level (TRL) method and also analyze the level of operator acceptance of the use of the EwacsPro system adopting Technology Accetance Model 2 (TAM2) using Structural Equation Modeling (SEM) analysis. The research will provide recommendations to the XYZ management for improvements related to EwacsPro at ABC Jobsite so that it can provide benefits according to the technological design which has been made, using Business Model Canvas (BMC) tool. The EwacsPro system reached level 9 TRL with a fulfillment rate of 80%. There are 7 variables that significantly influence EwacsPro's Usage Behavior directly and 1 variable that significantly influences using 2 influencing moderator variables of the TAM2 analysis. The R-square test also shows that all values are above 0.75, which means that there is a strong influence from the measurement of the exogenous latent variable on the endogenous latent variable.

Construction method of high-horsepower tractor digital twin

Background Agricultural machinery equipment is the core element of advanced agricultural productivity. The operation system of agricultural machinery equipment involves machine-human-environment-society interactions. Limited by the production mode, operation mode, etc., the design and development, manufacturing, operation and maintenance control, recycling and other links of agricultural machinery equipment are still independent of each other. The massive information in the agricultural production process has not been fully utilized, so there are some outstanding problems such as low operating performance, low production efficiency, and poor integration of agricultural machinery and agronomy. Methods Focusing on the agricultural production process, this paper proposes the construction method for a high-horsepower tractor digital twin, and expounds on its operation mechanism. Taking high-horsepower tractor ploughing operation as an example, by deploying tractors, central servers, and an Internet of Things (IoT) platform, we developed a digital twin service platform for the agricultural production system of intelligent agricultural machinery equipment and built a tractor digital twin to verify the effectiveness of the proposed method. Results The accuracy rate of the tractor ploughing quality prediction service based on this platform is 96.65%. Under open-loop control, the number of excellent, good, medium and poor sets of the tractor ploughing quality are 153, 955, 1470, and 1422, respectively. After adopting closed-loop control, the number of excellent and good sets increased by 378, and 821, respectively, and the number of medium and poor groups decreases by 119 and 1080, respectively. Through this platform, the operation quality can be effectively and accurately predicted and improved, which verifies the effectiveness of the proposed construction method of high-horsepower tractor digital twin. Conclusions This research provides a method framework for the construction of the digital twin of tractor operation and maintenance control processes, and provides strong support for the vigorous development of intelligent agriculture.

Model of the non-stationary thermal processes in the ground heat pump system

One of the main directions for improving heat supply systems is the tendency to switch to low-temperature heating systems by using heat pump units is the tendency of implementation the low-temperature heating systems based on the use of heat pump units. In the work, the main attention is focused on the improvement of thermal parameters and circuit design features of elements of the heat pump system of heat supply using soil energy. For this purpose, the toolkit of mathematical modelling of processes in ground heat pumps is applied, taking into account the climatic conditions of Ukraine. The paper proves the technical possibility of creating an autonomous system of alternative heat supply for energy-saving technologies with the possibility of using ground energy, taking into account environmental requirements. It is substantiated that the use of the proposed systems is a promising direction for Ukraine, which is experiencing a shortage of its own energy resources, because it provides an opportunity to increase the share of organic fuel substitution and reduce the volume of heat emissions into the environment. A mathematical model of heat processes in the elements of the heat exchange equipment of the heat pump system based on renewable energy (soil energy) and secondary energy (wastewater) was developed, taking into account environmental requirements (preventing hypothermia of the soil during the operation of soil pipes and damage to vegetation, respectively), which allows choosing a rational mode of operation of the system under seasonal climatic changes and technological conditions. Numerical modelling of heat processes in elements of the heat exchange equipment of the heat pump system using groundwater and waste water was performed, and the energy and environmental efficiency of the system under variable climatic and technological factors was determined. Analysis and generalization of the calculation results of the heat pump heat supply systems using alternative energy based on the proposed mathematical model, taking into account environmental requirements (preventing thermal relaxation of the soil) allows to take into account the change in the temperature gradient around the soil heat exchanger and more accurately determine the heat flow from each section of the heat exchanger. It has been established that for heat pumps with soil heat exchangers, the maximum substitution ratio of the traditional fuel is 75 %, and the economically feasible quantity of soil heat exchangers is 9 units. Heat pumps using waste water can completely replace traditional heat supply systems. For individual consumers, it is possible to recommend heat pump units with soil heat exchangers, at the same time, it is necessary to provide a backup source of energy to increase the reliability of heat supply.