Exchange Technology Research Articles

Business accounting and information support through the QR- coding system

Business accounting and information support through the QR- coding system

Heat transfer performance and electrohydrodynamic characteristics optimization of a dividing-wall-type ionic wind heat exchanger

Heat exchangers play a major role in reducing emissions and conserving energy. There is a plethora of theoretical research on the enhancement of heat transfer caused by ionic wind, but there is still a lack of studies on the practical application of ionic wind in heat exchangers to increase heat exchange capacity. This work developed an original ionic wind heat exchanger with a dividing wall. It may be applied to difficult circumstances when conventional heat exchangers fail for air-to-air heat exchange. The study conducted experiments to investigate the impact of many factors, including intake air velocity, discharge spacing, and electrode distribution scheme, on the ionic wind intensity and the heat exchanger's increased heat transfer coefficient. A two-dimensional model was used to analyze the internal flow and thermal properties of the heat exchangers with wire emitters. By combining active and passive heat exchange technologies, an ionic wind heat exchanger with serrated grounded electrodes was presented. The outcomes demonstrated that a suitable intake air velocity enhances the heat exchanger's capacity for heat exchange. The improved heat exchange effect of ionic wind is more important when the inlet wind speed is less than 1 m/s. When the intake air velocity approaches 1.3 m/s, the ionic wind has less of an impact on the heat exchanger's capacity for heat exchange. The benefits of improved heat transfer are promoted by placing the emitter closer to the channel entry. Increasing the operating voltage further enhances the heat transfer enhancement ratio (HTER). The number and arrangement of wire electrodes should be chosen with consideration for the 'barrier effect' between neighboring emitters and the distance from the entrance when utilizing multiple wire electrodes. In comparison to the three-wire and five-wire electrodes, the four-wire electrode heat exchanger's HTER values were increased by 5.9 % and 14.3 %, respectively. The ionic wind heat exchanger's capacity for heat transfer is further increased using a zigzag grounding electrode. The zigzag uses a decreased aspect ratio, and the emitter is positioned slightly above the tip, improving the system's heat transfer capabilities. When compared to a heat exchanger with a flat plate grounded electrode, the four-wire electrode heat exchanger produced a 158 % increase in HTER value.

Life cycle assessment and techno-economic analysis of nanotechnology-based wastewater treatment: Status, challenges and future prospectives

BackgroundWater pollution is a pressing concern stemming from both natural and anthropogenic activities. The challenges associated with water treatment technologies are adsorption (fouling and corrosion of the adsorbent), flocculation (increased sludge generation and high operation cost), ion exchange (high cost and improper ion removal), chemical precipitation (sludge generation), and membrane technologies (membrane fouling and storage). These technologies have been overstretched and struggle to meet increasingly stringent water quality standards. More recent progress has been made in using nanotechnology for wastewater treatment. Nano-technology offers several advantages over traditional technologies. Many nano-based technologies support reuse, require less space, produce fewer toxic intermediates, and are adaptable to support the emerging concept of decentralized water treatment. An essential aspect of this review is a detailed techno-economic analysis, assessing the long-term viability of nanotechnology-based wastewater treatment methods from an economic standpoint. MethodsThis review outlines the current state of nanotechnology in wastewater treatment, addressing environmental and economic aspects, challenges, and future potential. Significant findingsUnderstanding the sustainability and feasibility of these innovative technologies is crucial for their successful integration into wastewater treatment practices, ensuring a more effective and environmentally friendly approach to water remediation.

Improving tertiary education via remote learning: Insights from students and educators

Relevance. The growing adoption of distance learning in higher education necessitates an understanding of the pedagogical conditions that facilitate its effective implementation. Purpose. This study aimed to identify the pedagogical conditions that support successful integration of distance learning technologies in higher education. Methodology. A questionnaire survey was conducted among 206 first- to fourth-year pedagogy students, complemented by interviews with 28 teachers. The survey and interviews focused on experiences, advantages, and disadvantages of distance learning from both students� and teachers� perspectives. Results. The findings revealed that 89% of students favoured distance learning, highlighting benefits such as time and budget savings, comfortable home learning environments, easy access to necessary information, and flexible learning schedules. However, 11% of students reported dissatisfaction due to issues like internet outages, perceived lower quality of education, and lack of communication with peers and instructors. Teachers identified several challenges, including students� information assimilation, their own adaptation to teaching in distance formats, and administrative hurdles. Conclusions. Distance learning technologies, distinct from traditional methods, emphasize independent student activities and the use of information technology for knowledge exchange. Addressing the identified challenges and leveraging the benefits can significantly enhance the distance learning experience. Keywords: student adaptation; self-education; network technologies; digitalisation in education; pedagogical conditions

Construction of a stable expression HEK293T engineered cell line adapted to high-density suspension culture

The HEK293 cell line has received FDA approval and is increasingly used to produce therapeutic glycoproteins. However, the cell line faces the challenge of long-term expression instability. This problem could be solved by specifically integrating exogenous genes into stable sites and developing a HEK293 cell platform to efficiently and stably express recombinant proteins with large-scale suspension culture. The study uses CRISPR/Cas9 and recombinase-mediated cassette exchange (RMCE) technologies to integrate a variety of exogenous genes into specific chromosomal sites, such as the hROSA26 site, AAVS1 site, and CCR5 site. We evaluated the stability and expression intensity of exogenous proteins at different insertion sites under suspension culture conditions. A monoclonal cell line expressing enhanced green fluorescent protein (EGFP) is obtained using CRISPR/Cas9-mediated specific integration. The positive monoclonal cell lines express EGFP after 60 consecutive passages, and no significant differences in protein expression titer are observed. These results show that, under suspension culture conditions, the hROSA26 locus could stably express exogenous proteins after 60 generations. HEK293 cell lines integrating HSA (68 kDa) and IFNβ-HSA (89 kDa) genes at the above three sites were obtained respectively using Bxb1-mediated RMCE technology, and batch experiments demonstrated their expression capacity. In summary, a stable and efficient protein expression platform of HEK293 cells is successfully constructed and could be adapted to serum-free suspension culture.

Geothermal In-Situ Heat Transfer Control Factor Simulation and Numerical Analysis

Geothermal energy, as a renewable and clean energy source, holds immense potential in meeting energy demands and reducing carbon emissions. Its unique sustainability and environmental friendliness make it an important complement to addressing today's energy challenges. Coaxial tubing in-situ heat exchange technology for geothermal wells, as a key extraction method for geothermal energy, is subject to control by multiple critical factors that directly relate to its efficiency and feasibility. This paper aims to delve into the technology of coaxial tubing in-situ heat exchange for geothermal wells through numerical simulation analysis, with a focus on studying the impacts of three key factors on its performance: heat transfer medium flow rate, inlet water temperature, and cement thermal conductivity. Through numerical analysis, this study aims to reveal the variations of these factors to provide more refined control methods and optimize the coaxial tubing in-situ heat exchange technology for geothermal wells. By conducting experimental simulations and numerical analysis on these key factors, this paper aims to provide strong support for optimizing the coaxial tubing in-situ heat exchange technology for geothermal wells, which will contribute to advancing geothermal energy technology and promoting the sustainable utilization of clean energy.

Research on the Application of Virtual Reality Technology in the Cultural Exchange of Tourist Attractions Under the Background of Artificial Intelligence

Virtual reality is an immersive interactive technology that captures the entire location within 360 degrees with the help of special cameras, mounts and software. This paper discusses the role of artificial intelligence technology and virtual reality technology in the cultural communication of tourist attractions. In tourist attractions, VR technology provides a glimpse of information about the tourist attraction with the help of VR photography and VR video. This study provides a new idea for the design of interactive cultural communication devices and uses supervised learning algorithms to make their versatility and interactivity fully reflected in the communication effect . The results of the study show that by using supervised learning algorithms, artificial intelligence based virtual reality provides 97% high accuracy.

Determination of technogenic risks when using various water purification technologies

In modern conditions, ensuring the reliability and safety of water supply systems is a primary task for the industrial economy and the safety of life of the population of Ukraine. Constant bombing and damage to critical infrastructure facilities, including water management facilities, endangers the stability and quality of the country's water resources. In this context, conducting research on the identification of man-made risks in water treatment systems using various technologies, as well as developing strategies to increase the reliability and safety of operation of water supply systems are becoming relevant for the industrial sector of Ukraine. In order to increase the reliability of water treatment units and their operational safety, man-made risks were investigated when using ion exchange, electrodialysis, and water distillation technologies at thermal power plants. It is shown that during normal operation of the ion-exchange water purification system with an average productivity of 400 m3/h, in the case of frequent changes in the concentration of salts at the inlet, the risk of receiving underpurified water is 0.0783. This value must be taken into account for the assessment of economic and social-ecological risks, since it exceeds the generally accepted value of 0.01. When using electrodialysis water purification and frequent changes in the concentration of salts at the inlet, the risk of receiving underpurified water is 0.0271. This value is also greater than 0.01 risk accepted as acceptable. The water distillation technology has enough margin to compensate for any deviations in the purification process and gives a very low risk. However, the distillation process is more effective in removing only soluble impurities, while in the case of suspended substances, in particular of organic origin, there is a risk of exceeding the limit of 0.01.

Review of Operation Performance and Application Status of Pulsating Heat Pipe

Due to the rapid development of science and technology in today’s era, electronic equipment is constantly upgrading. Today, the developmental trend of electronic equipment is miniaturization, portability and multi-functionality. However, multi-functionality often means multi-components, so it is undoubtedly a great test of heat dissipation ability to accommodate more components in a smaller volume. Without sufficient heat dissipation capacity, a large number of components will stop working or even be damaged because of the heat generated during operation. As a new passive cooling and heat exchange technology, pulsating heat pipes have many advantages, such as having no external energy input, a simple structure, changeable installation forms and low installation requirements. They have shown great potential in the field of thermal management, and have attracted a lot of scholars’ attention since they were put forward. Because of their operational stability and heat exchange ability in high heat flux environments, they are the best choice for cooling electronic equipment at present. If they can be fully studied and utilized, pulsating heat pipes can not only reduce the consumption of heat dissipation resources but also reuse heat energy to realize the sustainable utilization of resources. This paper briefly introduces the demand background and structural principle of pulsating heat pipes, and summarizes the research on the parameters of pulsating heat pipes and the application status of pulsating heat pipes. The parameters involve working fluid type, pipe diameter, elbow number, liquid filling rate, inclination angle, etc. After classifying the parameters that affect the operation results of pulsating heat pipes, this paper summarizes the research at this stage, and points out the lack of research fields, such as heat flux density, and new application fields of unconventional gravity environment by combining the literature content with the current scientific and technological development trends and experimental parameters, such as thermodynamics.

'WASAP': WARM as soon as possible - A low-cost instant blood warmer based on dual tube heat exchanger and nanofluid technology.

'WASAP': WARM as soon as possible - A low-cost instant blood warmer based on dual tube heat exchanger and nanofluid technology.

Asymmetries in tourism demand

ABSTRACT This research investigates the impact of key macroeconomic determinants on tourist demand in Greece, focusing on destination competitiveness, income levels, real interest rates, real exchange rate volatility (ERV), trade openness, technology infrastructure, human capital, and travel costs. By introducing a novel index, the study comprehensively evaluates these influences on Greece’s tourist influx over the long term. It also explores the asymmetric long-term impacts of ERV and tourists’ income, highlighting the importance of the direction and size of these effects. The findings are essential for developing effective long-term economic policies to enhance tourism in economies like Greece, where tourism significantly contributes to economic development.

Highly Sensitive On-Chip Grating-Based Optical Sensor on Glass Substrate: Cost-Effective Design

This paper presents a novel on-chip optical sensing system using ion exchange technology and phase-shifted Bragg grating design. The sensor geometry has been optimized using a finite difference time domain (FDTD) solver to achieve maximum sensitivity and figure of merit (FOM). The proposed design offers high sensitivity to changes in refractive index and low fabrication costs. The ion exchange process used to create the sensor allows for precise refractive index control, optimizing the sensor’s sensitivity and FOM. A graded-index waveguide and a phase-shifted Bragg grating structure also contribute to the sensor’s high sensitivity. The proposed sensor design was tested for water-based sensing applications, achieving a FOM of 227.63 and a 343.1 nm/RIU sensitivity. These values are significantly higher than those reported for other Bragg grating sensors, highlighting the potential of the proposed design for high-performance sensing applications. The sensor’s high sensitivity and low fabrication costs make it a promising technology for future sensing and monitoring applications.

Field installation of ion exchange technology for purification of retention reservoirs from nitrogen-based nutrient contamination

N- and P-nutrient contamination is recognised as one of the key factors that reduces the quality of water. In this context, a new water purification installation was set up in the Turawa reservoir (district Opole, Poland). The process involves ion exchange columns operated in twin configuration: once one column filtrates water, the second one regenerates. The installation design is modular, and the devices are placed in a container station. This enables efficient water purification in various locations and further offers scalability. The research focused on the design and optimization of the installation, as well as environmental assessment of how the installation influenced the quality of water. This technology afforded a decrease in the concentrations of NO3− ions, suggesting an apparent selectivity. The removal of NO3− reached 97 % and was maintained for over 100 m3 of purified water. In turn, the removal of PO43− was not effective; however, the collected data allowed the installation design to be adjusted such that the cascade arrangement of ion exchange columns can be considered. The technology was assessed over all four seasons in the two-year test period (2020−2021). This revealed that environmental factors, such as season, air temperature, wind, and relative humidity, influence the operation of the installation. The installation functions optimally in spring with an average air temperature of 11–20 °C, high relative humidity of 90–100 %, and an average wind speed of 2 m/ s. The implementation of the technique could easily broaden the perspectives of Earth's water preservation and sustainability.

Zeta potential and activation energy effects in an EMHD non-Newtonian nanofluid flow over a wedge with Darcy-Forchheimer porous medium

The transmission of mass and heat alters the distinctive of non-Newtonian nanoliquid, which have several applications including extrusion, cooling of metallic plates, transport of biological fluids, coating, heat exchanger technology, and feed roll material movement. Mass and heat transfers in tangential hyperbolic nanoliquid streams via a wedge were analyzed, along with the roles played by Arrhenius activation and electro-magneto-hydrodynamics. Additionally, the impact of Darcy-Forchheimer flow and magnetic fields are considered in this simulation. By choosing suitable similarity variables, the necessary nonlinear partial differential formulation is transformed into nonlinear ODE’s (ordinary differential equations). After that, the equations are solved in Matlab through BVP4c solver. Flow fields, heat and mass transfer primary affecting factors were shown in graphically and discussed. Also, the coefficient of skin friction, Nusselt and Sherwood numbers are also presented graphically in the primary influenced parameters. An escalation in the Weissenberg number causes a decrease in the values of nanoliquids velocity, but an escalation in the power law index parameter causes an enhancement in nanoliquids velocity. If the suction and injection fluid have a zeta potential opposite that of the surface, it may improve interaction and change the boundary layer, thereby decreasing the coefficient of skin friction.

Clostridium Bacteria: Harnessing Tumour Necrosis for Targeted Gene Delivery.

Necrosis is a common feature of solid tumours that offers a unique opportunity for targeted cancer therapy as it is absent from normal healthy tissues. Tumour necrosis provides an ideal environment for germination of the anaerobic bacterium Clostridium from endospores, resulting in tumour-specific colonisation. Two main species, Clostridium novyi-NT and Clostridium sporogenes, are at the forefront of this therapy, showing promise in preclinical models. However, anti-tumour activity is modest when used as a single agent, encouraging development of Clostridium as a tumour-selective gene delivery system. Various methods, such as allele-coupled exchange and CRISPR-cas9 technology, can facilitate the genetic modification of Clostridium, allowing chromosomal integration of transgenes to ensure long-term stability of expression. Strains of Clostridium can be engineered to express prodrug-activating enzymes, resulting in the generation of active drug selectively in the tumour microenvironment (a concept termed Clostridium-directed enzyme prodrug therapy). More recently, Clostridium strains have been investigated in the context of cancer immunotherapy, either in combination with immune checkpoint inhibitors or with engineered strains expressing immunomodulatory molecules such as IL-2 and TNF-α. Localised expression of these molecules using tumour-targeting Clostridium strains has the potential to improve delivery and reduce systemic toxicity. In summary, Clostridium species represent a promising platform for cancer therapy, with potential for localised gene delivery and immunomodulation selectively within the tumour microenvironment. The ongoing clinical progress being made with C. novyi-NT, in addition to developments in genetic modification techniques and non-invasive imaging capabilities, are expected to further progress Clostridium as an option for cancer treatment.

Modelling and optimization of Li+ extraction from brine with high Mg/Li ratio by electrochemically switched ion exchange considering thermodynamics and dynamics simultaneously

Electrochemically switched ion exchange (ESIX) technology has been proven to be an efficient and environmental-friendly method for extracting Li+ from brine lakes. To deeply understand and mathematically express the underlying physical process of Li+ extraction in ESIX, a model is developed to describe Li+ extraction from brine lakes with a high Mg/Li mass ratio (500:1) by ESIX with an electrode coated with λ-MnO2 film. The kinetics and thermodynamics of the Li+ extraction process is considered simultaneously by coupling the Frumkin-Bulter-Volmer theory modified by electroactive site concentration with a modified Gouy-Chapman-Stern model. The local sensitivity analysis indicates that the performance of ESIX in Li+ adsorption is greatly influenced by cell voltage, film mass, and Stern capacitance of carbon black film, whereas these parameters have little effect on Mg2+ adsorption. The individual parameter analysis elucidates that the mass and Stern capacitance of carbon black film can regulate the potential drop distributions in different regions of ESIX system, resulting in a maximum Li+ extraction efficiency of 90.22 % due to the increased driving force in the faradic reaction and reduced charge transfer resistance. The optimization of combined parameters indicates that the optimum operation can be achieved at the conditions with a cell voltage ranging between 1.0 and 1.2 V, a Stern layer capacitance with electric double layer volume for carbon black film of 5.4 × 107 F/L, and an initial Li+ content of the treatment solution: carbon black film: λ-MnO2 film mass ratio of 0.1 kg: 9 kg: 8 kg.

Magnetic Levitation Remote Control Laboratory Based on Matlab and Websockets

This work proposes a novel architecture for constructing remote laboratories, employing modular building blocks: Matlab/Simulink software for control system design and simulation, WebSocket communication technology for continuous data exchange, and a front-end application developed using the Angular framework. To facilitate WebSocket communication on the Matlab server side, the MatlabWebSocket library is implemented. Beyond the Angular framework, interactivity within the remote laboratory is further enhanced through 3D visualization of the controlled system using a Three.js based library.These combined technologies are applied in the development of a remote laboratory for a fast, unstable, and nonlinear magnetic levitation system. The laboratory allows users to remotely set desired values and control parameters for experiments, while also providing continuous data visualization in various forms, including numerical readouts, graphs, and 3D animations. This approach demonstrates the effectiveness of the proposed architecture for building remote laboratories for complex systems.

Study of technological parameters of ion exchange resins and technology of recultivation of off-balance uranium-containing dumps

Study of technological parameters of ion exchange resins and technology of recultivation of off-balance uranium-containing dumps

Energy conservation of HVAC systems in isolation rooms using heat pipe heat exchangers

Isolation rooms are crucial in healthcare facilities to prevent the spread of infectious diseases. Infectious diseases can be transmitted to humans from humans or through animals known as zoonoses. With the increase in the number of COVID-19 cases, isolation rooms have become one of the most critical facilities in hospitals. Maintaining the correct temperature and humidity in these isolation rooms is a challenge, considering the heating, ventilation, and air conditioning (HVAC) systems that continuously consume large amounts of energy. With the application of energy conservation methods, the total energy consumption of HVAC systems can be reduced. Many studies have shown that the heat pipe heat exchanger (HPHE) technology can contribute significantly to energy savings using HVAC systems. In this study, the effectiveness of an HPHE on an HVAC system in an isolation room was examined, and the total energy reduction was quantified. The HPHE consisted of two rows with ten heat pipes in each row, arranged in a staggered configuration with fresh air temperature and mass flow variations. The inlet fresh air temperatures varied at 32, 35, 37, and 40 °C and fresh air velocities at 1.2, 1.6, 2.2, and 2.6 m/s. Using a chiller, the inlet fresh air was cooled to a comfortable temperature zone, approximately 24.4–25.2 °C, in the isolation room. Notably, higher velocities decreased the effectiveness of the HPHE. An increase in the flow rate enhanced the system, thereby improving the heat recovery value. The increase in the inlet fresh air temperature from 32 °C, that yielded an energy saving of 1.23 W, to 40 °C, resulted in a further energy saving of 1.85 W. The application of the HPHE in the HVAC system in isolation rooms represents a significant innovation that contributes to a reduction in total energy consumption.

An energy efficient hybrid membrane technique for the removal of toxic metals from aquatic environment

Electrodeionization (EDI), integrates electrodialysis (ED) and ion exchange (IE) technology. The purpose of this study is to utilize an EDI unit for eliminating copper from wastewater. This process was demonstrated using a three-compartment system, comprising a central compartment filled with a cation exchange resin (CER), separated from the anodic and cathodic chambers by two cationic exchange membranes (CEM), with the anode and cathode placed in the anodic and cathodic chambers, respectively. Purolite C 160 was used to showcase how operational variables, such as initial concentration, contact duration, resin dosage, and temperature, were optimized for the most effective copper removal during batch mode operation. The optimized conditions were an initial concentration of 100 ppm, a Purolite C dose of 0.5 g/L, a contact time of 1 h, and a pH of 8. At an initial copper concentration of 100 ppm and a supply voltage in the range of 10 to 25 V, the highest copper removal achieved was close to 99.98 per cent. For this study, copper was eliminated in the described experiments up to 99.98%, with energy consumption in the EDI unit varying between 3.87 and 25.29 kWh per kg of removed copper.