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As a new type of two-dimensional nanomaterial, two-dimensional transition metal carbon/nitride (MXene) has attracted much attention because of its high specific surface area, high conductivity and solvability. MXene is often used as a basic material to construct macroscopic composites. In recent years, it has been used to manufacture MXene structural-functional integrated fiber materials and mqd derivatives of MXene, which has a wide application prospect in multifunctional fibers, energy conversion and storage (ECS), sensors, catalysis and lubrication, electromagnetic shielding (EMI), supercapacitors (SCs) and so on. And has achieved some results. In this paper, the international research progress of MXene materials in recent years is reviewed, and its structure, properties and preparation methods are summarized. On this basis, its development in the field of energy storage (such as supercapacitors) is summarized, the shortcomings in this field are pointed out, and the future development trend is prospected.

The usage of hybrid structures brings advantages in their application. Structures with appropriately combined materials within the supporting structure are able to withstand higher loads and overcome larger spans. Effective structural solutions can also be achieved by combining materials such as cross laminated timber, concrete, and steel. The result is the achievement of a more efficient construction and at the same time achieve an aesthetic, but also an ecological structure, furthermore, creating a slimmer ceiling structure can ensure financial savings. In order to achieve the maximum use of the potential of the structure, it is necessary to create suitable structural connections. By creating a suitable joint among the ceiling decks and the beam, it is possible to create a load-bearing ceiling structure that behaves like a continuous deck. In this paper, numerical analysis of selected types of joints are performed and compared. During the examination, an adjustment has been made for alternative joint variation. After updating the proportions of components in this specimen, alternative sample of joint was able to withstand loads applied during analysis. Examined joint connection offers alternative to original joint connection.

The nonlinear effects in the fiber lasers have always been explored and studied as people are pursuing higher quality fiber lasers in different wavelengths for profound applications. In recent years, 1.7 μm band fiber lasers have received the tremendous attention due to their unique spectral properties in biological imaging, organic gases detection, material processing and other fields. In this paper, the research progress of nonlinear effects-based 1.7 μm fiber lasers is thoroughly reviewed. Meanwhile, the four nonlinear effects applied in 1.7 μm fiber lasers included stimulated Raman scattering (SRS), super-continuum (SC), four-wave mixing (FWM), soliton self-frequency shift (SSFS) are introduced, as well as the principle, characteristics and advantages of each method. In addition, the latest researches on the 1.7 μm fiber lasers based on the hybrid gain are summarized in detail. Finally, the conclusion included the obstacles and adversities is given and the future development tendency of nonlinear effects-based 1.7 μm fiber lasers is prospected.

The requirements on structural engineers to design more subtle flat slabs are still increasing and therefore they must often design a large amount of reinforcement against punching. The maximum amount of transverse reinforcement is limited by the maximum punching capacity of slab, so the precise determination of the limit is essential. In the second generation of Eurocode 2, the model for the assessment of the maximum possible increase of the punching shear resistance of slab is less empirical and it considers the performance of the punching shear reinforcement. The main objective of the paper is to develop nonlinear finite element model, which would determine as closely as possible the maximum punching capacity of flat slab, strongly reinforced with punching shear reinforcement. So that, an effect of some transverse reinforcement’s parameters on the maximum punching shear strength could be investigated quite easily. For this purpose, the software GID was used. The calibrated NLFE model showed quite good agreement with experiment. The difference is less than 8 %, even for slabs reinforced with double-headed studs it did not exceed 1%.

According to the experience in the construction of water conservancy and hydropower projects in the Mainland, RCC dam construction has two main advantages: the rapid construction speed of roller compacted concrete can realize early power generation, and the price of fly ash is much lower than that of cement, which can reduce the project cost. Tibet has special geographical environment and climatic conditions, and generally has the characteristics of “high altitude, low pressure, low temperature, large temperature difference between day and night, and dry climate”. Taking the dam-building environment in central Tibet as an example, through investigation and research and analogy of similar projects, this paper analyzes the adaptability of construction of RCC gravity dams in Tibet from the aspects of geographical environment, climatic conditions, material properties, construction progress, and project cost. Adaptability to high altitudes. It provides a reference for choosing a safe, reliable, economical and reasonable dam type in the construction of water conservancy and hydropower projects. It provides reference for selecting safe, reliable, economical and reasonable dam types in water conservancy and hydropower engineering construction.

In this paper, high density rigid polyurethane foam is used as sandwich skeleton and shear thickening fluid as material core. A shear thickening fluid/polyurethane sandwich structure with light impact resistance was designed and fabricated. High strain rate impact test was carried out. It was found that STF-2/PU reached the peak load of 4978N in 13 ms after receiving 20 J impact energy, and the energy absorption ratio was as high as 43%. The shear thickening fluid/polyurethane honeycomb sandwich foam prepared by secondary foaming process has stable structure and can effectively absorb impact energy to achieve good protection effect.

Transmission lines are affected by the natural environment for a long time, and bolts are prone to frequent vibration, resulting in loosening or falling off. In this paper, the loose mechanism of transmission line threaded connection is analysed, and the transverse vibration comparative test of bolt locking method is carried out. A new type of locking nut has been developed, which has good locking performance and convenient installation. According to different operating environments, the principle of differential bolt locking is proposed.

Weathering will cause the proportion of chemical composition of ancient glass products to change, thereby affecting the classification judgment of glass type. In order to reasonably analyze the composition content of ancient glass products, this paper provides a reference for studying the content change trend of glass weathering by exploring whether the appearance of glass cultural relics affects the weathering trend and the weathering composition law. According to the relationship between glass surface weathering and ornamentation, color and glass type, a linear regression model is constructed, and in order to solve the problem of heteroscedasticity in the perturbation term, the OLS robust + standard error method is used to improve the model parameters. The results show that the ornaments are B and C and are more likely to weather, high potassium glass is easy to weather, the color is green is mostly unweathered glass, and the color is black There is a tendency to change to weathered glass. The lower the content of potassium oxide, iron oxide and alumina in high potassium, the easier it is to weather, the higher the silica content, the easier it is to weather, and the regularity of weathering and component content of lead barium compared with high potassium is not obvious.

Cities represent a massive area of dense materials that accumulate heat, do not retain rainwater, and therefore create an unpleasant condition for life. Many countries apply green roofs as an effective and practical tool to mitigate the adverse effects of urbanization. They are often designed as intensive and extensive. In recent years, a lot of research has been done on green roofs for a better understanding of their behavior in different conditions. In recent years, experimental green roofs have also started emerging in Slovakia. At the same time, the idea of restoring vegetation to industrial zones with help of such construction was made. The paper focuses on the latest planned phase of the project for the greening of an office building with an adjacent area in an industrial zone. Phase five consists of the design of a biodiverse green roof that will provide an alternative habitat for fauna and flora. The main elements of the design are the compositions of green and wetland roofs. Moreover, the paper summarizes the already implemented phases of the project.

The global buildings industry has an enormous responsibility to transform towards a regenerative and decarbonized future. The new project SECOVE 101056201 aims to establish a network of cooperation among Centre of Vocational Excellence (CoVEs) in the sector of clean and sustainable energy. The CoVEs will be established in 5 European countries (Greece, Spain, Italy, Slovakia, and Portugal) and will all cooperate transnationally with each other through common structured forms of dialogue and communication. The paper deals with the main activities and goals.

In the previous study, different structures of hoppers were proposed. And the dust suppression performance of hoppers were evaluated. In this paper, different materials of hoppers were selected.And influence of different material on particle behaviors were studied based on the discrete element method (DEM). Results shows that the wall material with low collision recovery coefficient for the hopper has positive effect on suppressing dust diffusion.and the wall material with high static friction coefficient showed little effect on the particle flow state through the hopper.

With the application of new generation intelligent technologies such as big data, cloud computing and numerical simulation in engineering, the level of intelligent construction has been gradually improved. In the development process of intelligent construction, it faces many problems, such as new technology, safety, human recognition and so on. This paper studies the privacy protection of intelligent construction, analyses the causes of privacy disclosure on the basis of information classification, and then puts forward privacy protection methods. The research shows that the privacy security of intelligent construction needs to clarify the scope and formulate effective protection strategies.

Waste glass from fibreglass production is waste that is generated at various stages of production. In nature, it is a combination of glass fibres, fine dust, but also larger glass grains, for example also from leakages during production. This material is or may be contaminated by impregnation, lubricants or some impurities that prevent its recovery during production. The main objective of this study is to assess the suitability of glass fibre waste and to optimise the pre-treatment of the raw material for use in the composite. This paper describes the determination of chemical composition, mineralogical composition by X-ray diffraction analysis, determination of bulk density, water absorption and specific surface area. The results obtained are compared with the primary raw material - glass fibre. The results showed that the waste from glass fibre production is primarily composed of silica, calcium, alumina and boron. Minor components include magnesium oxide, sodium oxide, fluorine, iron oxide, strontium oxide, potassium oxide, titanium dioxide, sulphur dioxide and chromium oxide. The specific surface area of treated glass fibre waste correlates with the specific surface area of cement, which is a prerequisite for the use of this waste as a partial substitute for cement in the production of building materials.

The foam characteristics plays a key role towards the application of aviation apparatus, which also affected by several influencing factors. This paper focuses on researching the key factors of the foam characteristics of the domestic and imported aviation lubricating oils, by comparing a certain type of domestic aviation lubricating oil or imported aviation lubricating oil’s foam characteristics at different oxidation temperature or oxidation length by virtue of utilizing aviation lubricating oil oxidation experimental device. The influencing factors that impact foam characteristics were analyzed to provide important theoretic and experimental support.

The work deals with the modification of the properties of epoxy adhesive. The modification consists of reinforcing this adhesive with cellulose fibres. In the field of wood glued elements, the current research focuses on the possibility of increasing the ductile behaviour of the epoxy adhesive, which would significantly increase the ability of the adhesive to transfer the stresses induced by the volumetric changes of the wood adherend. For this purpose, the adhesive was modified with fibres having a reinforcing character, which may include cellulose fibres. Due to the epoxy resin’s non-polar nature and the cellulose fibre's hydrophilic nature, which inhibits the fibre's homogeneous dispersion, the fibres have been modified with silanes. This paper describes the effect of adhesive modification by determination of tensile and shear strength at different amounts of filling and different types of silane pre-treatment of cellulose fibres. The optimum filling amount can be considered as 1.0% filling of nanofibrillated cellulose (NFC) with epoxy-functional silane pre-treatment.

The issue of anchoring sheet metal components has been part of construction practice for a very long time. Sheet metal components can be found on most contemporary buildings and due to the increasing thickness of insulation the possibility of anchoring to the supporting substrate is a problem. This paper discusses the issue of the bonded joint size dependence on the load capacity for fastening sheet metal elements to ETICS facades. A thixotropic silane modified polymer adhesive was used for this research. It was concluded that the size has a significant effect on the load capacity of the joint and their dependence was described.

BIM, or Building Information Modelling, is the future of architecture, engineering, construction and operations. We very often associate this definition with new buildings, while 80% of buildings in 2050 already exist today. A significant part of them are historical buildings. It is important to know how we can use BIM in this context and how this modern design tool serves to model and manage the unpredictable situations and complexities of historic buildings. The dissimilarity, the difficulty of data exchange between interested parties and therefore the difficulty of standardization is in this regard the challenge to be overcome with older buildings. In connection with architectural heritage, information modelling of heritage buildings is referred to under the name of HBIM, which is a built architecture representation system composed of libraries of semantically structured and parameterized objects. The basic process is the processing of the data in our possession, which are all transferred to a BIM-type model. SCAN to BIM is an operation that allows you to connect a point cloud created by laser scanner or photogrammetry to develop historical building management models that can be used in different application areas: accessibility and improvement, archival documentation research, conservation and visualization of cultural heritage, reconstruction and management of heritage, artificial intelligence (AI) and virtual reality (VR).The purpose of the paper is to provide an basic overview of the concept of HBIM. The contribution provides a brief overview of the regulatory framework and an overview of the methodology and workflow in the mentioned area with the appropriate conclusions.

The hopper is a kind of important equipment in bulk handling process. In this paper, an experimental platform was designed. The experimental platform was mainly composed of a feeding head, a vertical conveying screw machine, a horizontal conveying screw and a lifting device, a supporting structure, the visual experimental system,the electrical system and the acquisition system. the particle behavior for hoppers can be assessed by the experimental platform. And the visual experimental system will help to investigate the real particle flow behavior and will provide instructions for hopper design in future

Under different types of internal and external faults of transformers, electrical quantities such as voltage, differential current and transformer oil flow rate change accordingly. In this paper, the variation law is studied, and the variation law of differential current and other electrical quantities under different types of faults and abnormal conditions inside and outside the transformer area is verified by simulation. The characteristics of faults inside and outside the area are different, and the faults inside and outside the transformer area are judged. At the same time, ANSYS Maxwell 3D, ANSYS Fluent and other software are used to model and simulate the transformer, and the oil flow rate changes under different operating conditions such as normal operation, external fault and internal fault of the transformer are analyzed.

A gas relay in the transformer, an important non-electricity protection equipment, only triggers the stem leaf spring for the serious gas alarm when the baffle rotates to a certain angle, which cannot judge the transformer fault in the event of heavy gas before running state and fault development process, this paper puts forward a kind of based on gas relay panel corner of transformer running state monitoring methods. The partial structure of the gas relay is improved, and the baffle corner signal is extracted by installing a Hall sensor on the back of the baffle. On this basis, this paper develops a test stand capable of simulating the baffle characteristics of gas relays at different fault energies. Subsequently, the baffle angle variation law under different fault energies is studied, and the influence of pipe pressure and pipe flow rate on the baffle angle is given. The results show that, based on this improved gas relay, the real-time baffle angle information can reflect the internal operating state of the transformer and provide an effective method for transformer operating condition monitoring.

This paper focuses on the usage of mesh density and element type in the analysis of 3D objects, which are crucial components of 3D object Finite Element Method (FEM) analysis. The document is based on theoretical principles and will be supported by practical numerical examples using the FEM software Abaqus. In order to conduct an accurate FEM analysis, it is vital to employ an appropriate mesh that is easily convertible for calculations and free from imperfections. The suitability of the mesh depends on two key parameters: density, which is determined by the material being used, and element type, such as tetrahedrons, hexahedrons, polyhedrons, and others. Different types of elements and mesh densities in FEM software often involve multiple settings that primarily impact the accuracy of the model, as well as the calculation time and convergence quality. This article is divided into three sections: the first part focuses on the theoretical foundations, the second part presents a practical example, and the third part offers conclusions and comparisons.

The development of cracks is a regular phenomenon that causes water and various chemicals to seep into the structure reducing the strength and longevity of the building. The intrusion of external materials might affect the reinforcements when exposed to moisture and CO2 exposure, degrading the structure. Regular maintenance and treatments are needed to fix the cracks and maintain the structure. Research is in progress identifying solutions to these issues with active and self-processes in concrete which aids in repairing the cracks by generating calcium carbonate (CaCO3) particles which could seal the porosity of concrete and micro-cracks. Various bacteria like Bacillus pasteurii, Bacillus subtilis, Bacillus cohnii and Bacillus sphaericus are chosen for the crack sealing treatment as those bacteria could survive in an alkaline medium. Distinct species of bacteria have various growth conditions. Bacterial self-healing treatments were situated in an environment containing various minerals and chemicals at a constant temperature and for a specific amount of time to develop healing properties. This paper investigates the different experimental works studied on self-healing processes in large concrete samples with different sizes and materials. Studies revealed that bacteria enhanced the systemic toughness, flow ability, durability, and flexural modulus of normal concrete. This paper also investigates the different mathematical formulations established to examine the stress-strain behaviour of bacterium, which has been utilized to increase the strength of concrete.

The power electronic transformer structure can increase the output side voltage while reducing the volume of the transformer, which has the effect of increasing power density and expanding the DC side. Based on the current research and application of the PET rectifier modules. The 12-pulse rectification is not prone to failure in simple structures, so it is usually suitable for medium and high-power occasions. This article first introduces the rectifier topology model and its ideal waveform in an ideal state. Considering the actual situation of the power grid and power electronic transformers, there are phenomena of leakage inductance and magnetic flux leakage. This paper focuses on the non-ideal state to derive the theoretical formula and waveform derivation. And the 12-pulse rectifier circuit is modelled and simulated in MATLAB/Simulink. The main consideration is the simulation model of the 12-pulse rectifier section. In this study, a three-phase AC voltage is used to go in series with a three-phase winding transformer to equivalently replace the PET.

In the past few years, there has been a growing concern about the pollution caused by fossil fuels, leading to a significant interest in photovoltaic power generation due to its clean and environmentally friendly features. However, suppressing leakage currents is a major problem for Non-isolated PV inverters. This paper focuses on the leakage current suppression methods, summarises three main leakage current suppression paths and systematically analyses and classifies the DC-bypass topology, the H5 topology and the Neutral Point Clamped (NPC) three-level topology. In order to address the issue mentioned above, several approaches can be taken. Firstly, a suitable sinusoidal pulse width modulation strategy is implemented. Additionally, alterations are made to the common mode impedance Z. Furthermore, efforts are made to ensure a proper match of circuit parameters. The analyses in this paper are all carried out based on bridge-type inverters to provide a reference for the study of leakage current suppression in Non-isolated Inverter. Future studies will be more efficient when similar issues arise.

The research for the new environmental friendly construction material that will match the durability of ancient concrete has provoked interest into the study of alkali activated cementitious systems over the last two decades. It results in the development of Geopolymer Concrete. This paper represents the development of geopolymer mixes of various ratios of fly ash and GGBS and their mechanical properties were studied. aa Literature review on mechanical and durability properties of geopolymer concrete also been done. The ratio of sodium hydroxide to sodium silicate is 1:2 which is kept a constant to prepare the mix and alkaline liquid to binder ratio as 0.70, but changing the concentration of sodium hydroxide solution as 6M, 4M and 3M to prepare the mix Id. i.e. F75G25, F50G50 and F25G75, respectively (where F and G are Fly Ash and GGBS and the numerical value indicates the percentage of replacement of fly ash by GGBS) were prepared in AML laboratory, CSIR-SERC, Chennai. Ambient curing of concrete at room temperature was adopted.The compressive strength at age of 3, 7 and 28 days were determined. The strength of geopolymer concrete was increased with increase in percentage of GGBS in a mix. It was observed that the mix Id F25G75 gave maximum compressive strength for concentration of NaOH as 3M . Leaching of GPC reduces with increase in percentage of GGBS in a mix. Thus the geopolymer concrete have a relatively higher strength.

Although concrete is a prominent building material in nearly all construction applications, it is also known for its reinforcement corrosion and thus material degradation due to crack formation. These severe durability issues ignited the use of microorganisms to self-heal concrete cracks in a biological way by promoting the precipitation of CaCO3 on their cell walls. Filamentous fungi have recently emerged as high-potential self-healing agents because of their ability to grow in large mycelial networks providing abundant nucleation sites for CaCO3 precipitation. Based on the extensive research already conducted on bacteria-based self-healing concrete, protection of the microbial spores in the concrete mix is key to the survival of the microorganism. This research therefore applied a natural encapsulation technique derived from bacteria-based literature on fungal spores. The fungus Trichoderma reesei, already known in the field of self-healing concrete, was used to prepare the capsules. First results showed that the fungus was able to withstand the encapsulation process, yet could not survive when embedded in cement due to its harsh conditions. The possibilities to optimize the procedure are however discussed in the paper and give rise to a broad range of research opportunities.

The emergence of digital technology has transformed the way we consume and interact with media, with one of the most significant innovations being the development of e-ink displays. These displays replicate the appearance of ink on paper, providing a low-power, high-contrast alternative to traditional backlit LCD screens. As a result of their advantages such as easy readability, low power consumption, and customization options, e-ink displays have gained widespread adoption in a range of devices such as e-readers, smartwatches, public signage, and transportation timetables. This paper aims to provide a comprehensive understanding of e-ink displays by examining their history, technology, current applications, advantages, and limitations. Additionally, the paper discusses the environmental and cost benefits of e-ink displays in contrast to traditional print media. The role e-ink displays can play in reducing paper waste and carbon emissions is emphasized. By exploring the unique features and benefits of e-ink displays, this paper provides a comprehensive overview of this important technology and its impact on the digital landscape.

The enormous quantity of sewage water produced each day continues to present a serious challenge for its treatment and management. Sewage water is one of the most abundant sources of biomass, such as bacteria. Concrete, on the other hand, is the second most widely employed substance on the planet, after freshwater. Cracking of concrete is a major factor affecting the strength and durability of the material. The development of a crack pattern can contribute to increasing the permeability of concrete, which is typically associated with a significant decrease in its durability. Under specific circumstances, bio concrete is a self-healing biomaterial. Bacteria have the ability to precipitate calcite in concrete or form a layer of calcite precipitation, which plays a crucial role in the remediation of plastic shrinkage microcracks, thereby enhancing the structural integrity and durability of concrete over the long term. This paper summarises the study of investigating the possibility of using sewage water as a self-healing agent, using bacteria from different stages of treatment to heal cracks in concrete samples, and evaluating the effect of sewage water from different stages of treatment on fresh and hardened concrete properties. Based on the data collected from the experiments. Complete replacement of ordinary tap mixing water with sewage water from the Biological Reactor oxygen Zone achieved cracks healing of a crack width of 200 μm in less than 14 days without compromising the binder and mortar properties such setting time, slump value, compressive and flexural strength when compared to a reference sample made with tap mixing water.

Technological progress has driven the rapid development of power electronics and enhanced the scale of the industry. SiC MOSFET devices have obvious advantages in applications such as high temperature resistance, high voltage resistance, and low switching loss. However, the different characteristics of such devices will bring related problems that seriously affect the reliability of the device and system. The drive circuit is effective in solving these problems with its small input resistance, parasitic inductance, and large enough drive voltage and current. Starting from the concept and related theoretical composition of SiC MOSFET driver module, this paper mainly analyses the impact of the driver module on the contemporary power electronics industry, and explains the application of the core research theory of the circuit to the industrial level. This paper also analyses the current situation of power electronics industry from the perspective of innovation theory, and looks forward to the prospect of power semiconductor devices.

Social media influences and celebrity endorsers are the dominant marketing strategies marketers follow to promote brands and businesses. The scholars also prioritized examining the diverse issues of social media influences and celebrity endorsers. On this ground, we systematically review the current trend of research to provide a state-of-the-art understanding of the factors prior researchers explored related to social media influences and celebrity endorsers to influence consumer brand purchasing behavior. We have extensively reviewed 200 peer-reviewed papers, including 86 research frameworks from recent (last five years) scientific double-blind articles that obtained at least four citations. We also deeply studied the social learning and source credibility theory used to test the proposed relationships. In the vein of the reviewed articles on social media influences and celebrity endorsers, we have summarized and listed the variables examined in different research contexts. The study reveals that interaction, customization, entertainment, word of mouth, and trendiness are the popular dimensions of social media influences, which the previous scholars explored to measure their effects on consumer brand purchasing intention in diverse contexts. Additionally, attractiveness, trustworthiness, credibility, and expertise are the widely used constructs for assessing the impact of celebrity endorsers on consumer brand purchasing behavior. To the best of our knowledge, this study is the first to provide a list of recent factors associated with social media influences and celebrity endorsers through which the scholars can get insight into the current trend of research. This study is the blueprint for future research to capture a quick view of recent trends in social media influences, celebrity endorsers, and consumer brand purchasing behavior. Finally, based on the comprehensive review of previous literature, we suggested a study to measure the associations of social media influences and celebrity endorsers with brand image, consumer attitude, and consumer brand choice behavior by the backdrop of social learning and source credibility theory in the context of any brands like Smartphone.

A structural assessment study on the “Humayun Palace” in Tamil Nadu, a cultural heritage structure, constructed in the early 1700’s was done. Based on the original design documentation collected through records, a static analysis model of the building was generated. This structure is a 3-storey building and details of all the provisions from the slab system to the roof tiles were made. The results developed by these models, aimed at fully understanding the original design concept of the various members, as well as at evaluating their current static and seismic safety conditions, are reported in this paper. This analysis was examined using E-TABS software, whose geometric limitations lead to minor encumbrances. Some complex geometric façade features were approximated to convenience and overcome. The results of the analyses highlight safe conditions and good performance objectives in general, but for some important exceptions. The overall satisfactory performance may be attributed to the overdesigning with excessive safety factors carried out by builders of that century, enabling the structure to withstand conditions way past its intended life. However, the question as to how well the structure will hold good in the future is hypothetical. It is for the same reason that the Public Works Department has allocated nearly 96 crore rupees for the rehabilitation of the same. This investigation is synchronous with the objectives of the said rehabilitation project and has established an exhaustive analysis of the structural health of the structure.

As the global demand for sustainable and environmentally friendly energy supply continues to increase, photovoltaic technology, as an important form of new energy, has received extensive attention. Photovoltaic grid-connected system is currently the most widely used form of photovoltaic power generation system. It converts direct current into alternating current and injects it into the grid to meet the power demand of users. However, the power grid imposes a series of requirements on grid-connected photovoltaic systems, one of which is the handling of harmonic problems. This article will focus on harmonic generation and how to perform THD (Total Harmonic Distortion) mitigation. As the key equipment of photovoltaic grid-connected system, inverter plays an important role in harmonic filtering. With a brief introduction to inverter-related THD. In this paper, by exploring how to optimize harmonic filtering to improve the performance and reliability of grid-connected photovoltaic systems, it is found that the method of suppressing THD by changing the PMW modulation is simple in calculation, easy to implement, and has high output waveform quality. And the method of suppressing THD by changing the equipment can reduce the harmonic quality.

Constructing a portfolio from a large number of active stocks is a critical as well as challenging investment decision due to high volatility and biased decision making. The abundance and availability of _nancial data gives machine learning (ML) an advantage to optimize investment decisions. The k-means algorithm is used to cluster observations into di_erent groups, each of which contains those with similar properties. In this paper, three factors are considered to cluster stocks and select clusters with best performing stocks for portfolio construction. It enhances the cardinal investment decision of stock selection to construct optimized portfolios. The out-of-sample performance demonstrates high economic gains from the proposed strategy with an average Sharpe ratio of 0.7.

The study focuses on the conservation of natural resources by replacing three vital construction materials: (i) Ordinary Portland Cement (OPC) with Marble Dust (MD) (ii) Fine Aggregate (FA) with tile in powdered form and (iii) aggregate with tile chips (TC) for the building construction works. In this present study, the abovementioned materials were used in 10, 20, and 30% as a replacement. As per the current scenario, only limited research papers are available that show what happens when the components are used as individual substitutions for the materials. Due to the lack of supporting evidence for material substitutions in concrete construction, the philosophy of experimenting with the use of mixtures of substitute materials in concrete has emerged. Experiments were conducted with M25 grade concrete, and the best mixes, M24 and M32, are mixes that replace all three traditional components of concrete, achieving strengths of 31.11, 2.76, and 8.0 N/mm2 in compression, 33.33, and 2.76, and 8.25 N/mm2 in flexure, respectively.

Silicon carbide (SIC) Metal-Oside-Semi-conductor Field-Effect Transistor (MOSFET) have excellent performance compared to traditional silicon components. The short circuit protection of SIC MOSFET plays an important role in ensuring the reliability and performance of SIC MOSFET. Due to the high internal heat flux and short short-circuit endurance time of SIC components, the short-circuit stability of SIC components is lower than that of silicon components. The paper briefly introduces two main types of SIC short circuit: hard switch short circuit and load short circuit and their characteristics, discusses the main types of contact and non-contact short circuit protection methods such as desaturation detection, parasitic inductance detection, gate voltage detection, shunt detection, instantaneous power consumption detection and Rogowski coil detection and compares their advantages and disadvantages. The desaturation detection method is the most widely used short-circuit protection method. Although the cost is low and the structure is simple, The desaturation detection has the inherent disadvantage of detecting the blind spot. The other detection methods overcome the defect of detection blind area, and the detection speed and accuracy are obvious advantages, but they also have their own limitations to limit their popularization.

In this paper, thermogravimetric analysis of different types/grades of polyvinyl chloride (PVC) wall panel is carried out using thermogravimetric analyzer. The data output from the analyzer is subjected to data analysis software i.e., OriginPro 2018, from which thermal attributes are find out for different grades of PVC wall panel i.e., soft PVC, hard PVC, WPVC and SPVC. The thermogravimetric attributes i.e., onset degradation temperature Ti, final degradation temperature Tf,, reaction interval and the peak temperature TP from the derivative thermogravimetric curve for the four basic types of PVC were comparatively analyzed for the characterization purpose. Beside the thermal characterization, the thermogravimetric analysis also disclosed the compositional attributes of the four types of PVC wall panel. The analysis in this paper characterized the SPVC as the most thermally stable PVC wall panel followed by hard, soft and WPVC.

The emergence of electric vehicles (EVs) has become a better alternative to withstand enormous damage to the environment and human life due to the widespread use of conventional cars. As a vital element in EVs, this paper analysed and compared the key features of different DC-DC topologies from different areas, then, explored strategies to improve DC-DC converter performance. The purpose of all these studies and designs is to help researchers in the automotive industry to choose the right DC-DC converter topology for their needs to achieve the required power density. By continuously improving the design and evaluation of DC-DC converters, it can improve the performance and efficiency of electric vehicles, and further promote the use of sustainable energy. This will help reduce reliance on traditional fuels, lower carbon emissions, improve air quality and move the entire transportation industry towards a greener, more sustainable future.

Solar photovoltaic power generation is crucial for combating climate change and promoting sustainable development. As the demand for renewable energy continues to rise, photovoltaic power generation offers a viable solution. This paper focuses on suppressing leakage currents in five-level photovoltaic inverters. By comparing and analyzing two types of inverters – the single-phase T-type five-level transformerless inverter and the single-phase asymmetric five-level transformerless inverter – using simulation and experimental data, the study reveals the effective suppression of leakage currents in both designs. The T-type inverter's unique configuration and advanced control algorithms significantly reduce leakage currents, while the asymmetric inverter's optimized design and operational parameters show notable proficiency in suppressing leakage currents. This research contributes to improving the performance and reliability of multi-level transformerless photovoltaic inverters, thereby supporting the widespread adoption of solar photovoltaic power generation as a sustainable energy solution.

Although steel reinforcements are used to withstand tensile forces in concrete, cracks are an unavoidable phenomenon. The presence of cracks, in fact, increases the risk for lowering the service life and durability of concrete structures. A critical issue occurs when due to splitting forces, cracks appear in concrete along the tensioned rebars which damage the bonding between the steel and concrete matrix. As a mitigation plan, the cracks should be healed at short notice and the bonding has to be recovered by the potential use of healing agents. This paper aims to investigate the bond behaviour of steel reinforcement in self-healing concrete. Two biomasses were employed as healing agents namely HTN (bacteria-based) and YEAST (fungi-based). The fresh and hardened properties of the normal and self-healing concretes were initially evaluated. The bond properties were investigated by performing pull-out tests on three different states of concrete: uncracked, cracked, and healed. Results revealed that the additions of biomasses did not induce negative effects on the compressive strength of hardened concrete. Moreover, the average bond strength of uncracked concretes containing HTN and YEAST improved by 20% and 8%, respectively, as compared with normal concrete. The introduction of a crack caused a significant reduction in bond strength regardless of the addition of healing agents. Nevertheless, it was found that the bond strength was slightly recovered after healing under water immersion.

This paper investigates the autogenous self-healing capability of conventional concrete (C30/37) mixtures with water encapsulated in sepiolite. Sepiolite was added in two conditions: previously saturated and dry, at a dosage of 5% by the cement weight. Sepiolite is added in substitution for the sand fraction. For these two mixes and a reference mix without sepiolite, disks of size f100x50 mm were produced and were pre-cracked at 28 days of age by splitting test until reaching residual cracks of 300±150 μm. Crack width was measured by using an optical microscope. Self-healing was promoted after pre-cracking in certain exposures: 1) continuous water immersion at 20°C for 56 days, 2) a high humidity environment at 20°C and 95% of relative humidity for 28 days and water immersion for additional 28 days, and 3) pre-saturation for one day and 55 days in a humidity chamber. Self-healing was analyzed with water permeability by comparing the results before and after the healing stage. Afterward, chlorides’ penetration through the healed cracks was evaluated to study the possible protection provided by crack healing. Uncracked specimens were also tested as a reference for chloride penetration. Mixes were characterized by measuring compression strength at 28 days, slump, air content, and fresh density. The results show that water immersion is an adequate way to improve autogenous self-healing. Sepiolite can improve the self-healing capability of concrete with only one day of pre-saturation and then healing in high humidity conditions, especially in mixes with sepiolite introduced in saturated conditions. On the contrary, sepiolite may have resulted in a higher chloride penetration compared to samples without sepiolite.

The state of Tamilnadu is located along the south west of Indian peninsula. The state has nearly 40 river basin and most of them are seasonal. The river Thamirabarani is one of the perennial rivers covering 3 districts namely Tenkasi, Tirunelveli and Tuticorin. The river originates from the eastern side of the west coast and confluences with Bay of Bengal at a village called Punnakayal in Tuticorin district. The Thamirabarani river is known for its irrigation potential in the upper reaches. By the time it reaches the lower end, the flow is very low. The east coast is well known for its littoral drift which is dominantly towards the north direction. The village is famous for its fishing potential. The study area of Punnakayal is influenced by two monsoons namely south west and north east. Due to absence of high flow in the non-monsoon period, the estuaries are highly blocked by sand bar formation. Because of this sand bar formation, the fisherman find it difficult to go in to deep sea during low tide time. Hence studies were made and remedial measures were suggested and completed. The details of hydrologic analyses, hydraulic modelling, hydrodynamic studies, assessment of littoral drift remedial measures and post project performance are detailed in the paper.

The laser-powder bed fusion (L-PBF) process presents advantages over other polymer additive manufacturing processes in terms of part strength and high production rate possible with the technology. The high cost and limited re-use of nylon powder used in the process however limit the large-scale adoption of the technology in industry. This paper investigated the re-use of PA12 powder that is no longer suitable for the L-PBF process through producing filament for the fused deposition modelling (FDM) process. Results from the study showed that parts with good mechanical strength and reasonable dimensional accuracy can be produced using FDM.

Building integrated photovoltaic (BIPV) system is a new and modern technique for solar energy production in Kandahar. Due to its location, Kandahar has abundant sources of solar energy. People use both monocrystalline and polycrystalline silicon solar PV modules for the grid-connected solar PV system, and they don’t know that which technology performs better for BIPV system. This paper analysis the parameters, described by IEC61724 “Photovoltaic System Performance Monitoring Guidelines for Measurement, Data Exchange and Analysis” to evaluate which technology shows better performance for the BIPV system. The monocrystalline silicon BIPV system has a 3.1% higher array yield than the polycrystalline silicon BIPV system. The final yield is 0.2% somewhat higher for monocrystalline silicon than polycrystalline silicon. Monocrystalline silicon has 0.2% and 4.5% greater yearly yield factor and capacity factors than polycrystalline silicon respectively. Monocrystalline silicon shows 0.3% better performance than polycrystalline silicon. With 1.7% reduction and 0.4% addition in collection losses and useful energy produced respectively, monocrystalline silicon solar PV system shows good performance than polycrystalline silicon solar PV system. But system losses are the same for both technologies. The monocrystalline silicon BIPV system injects 0.2% more energy to the grid than the polycrystalline silicon BIPV system.

Low density, high strength, high corrosion resistance, and biocompatibility are some of the attractive characteristics of parts produced through additive manufacturing from Ti6Al4V powder. This alpha-beta alloy is the workhorse of the titanium industry, and it is applied for manufacturing of structural components of aircraft, hydraulic systems, engine components, helicopter rotor blades, rockets and spacecraft. In the study presented in this paper, a plasma spheroidisation process was used to develop spherical powder from irregularly shaped commercial titanium Grade 5 powder. Properties of the powder relevant to metal additive manufacturing, namely particle shape and size, chemical composition, flow characteristics and density, were determined to establish the usability of the developed powder. It was concluded that plasma spheroidisation of irregularly shaped Ti6Al4V Grade 5 powder for AM application was feasible for powder size ranges between 45 and 150 μm, because the oxygen content did not increase for size fractions in this range.

Under China's relevant policies, the focus on civilian vehicles has shifted from fuel vehicles to new energy vehicles. However, there are a variety of choices for the positive electrode materials of battery systems, and different positive electrodes have different advantages. This paper investigates three cathode materials used in new energy vehicles, describes their preparation methods, and compares their performances. The results are that the highest first discharge specific capacity is for a lithium-ion battery prepared from LiNi0.94Co 0.04Al 0.02(OH)2 as the cathode material, and the highest first coulomb efficiency and cycle capacity retention is for a lithium iron phosphate battery prepared from a LiFePO4/C composite. The purpose of studying the three materials in this paper is to understand the advantages and disadvantages of the batteries used in the current new energy electric vehicles, and in the follow-up research, try to further improve their characteristics according to these their battery capacity and thermal stability.

New batteries are the mainstream of battery development, and many industries cannot live without new batteries. Most of the new batteries do not pollute the environment and exceed traditional batteries in terms of energy efficiency and charge and discharge times. This paper mainly introduces solid battery, metal battery, sodium ion battery, lithium sulfur battery, fuel cell and nickel-metal hydride battery. In addition, the new battery is compared with the traditional batteries represented by lead-acid batteries, zinc-manganese batteries, zinc-air batteries, zinc-silver batteries, zinc-mercury batteries and Mg-manganese batteries, so as to analyze that the new battery has higher energy under the same volume, and the service life of the new battery is far longer than that of the traditional battery while charging and discharging more times. And in the production and use or waste treatment process will not produce a large number of heavy metals or harmful gases harmful to the human body or the environment, more friendly to the human body and the environment. However, the new battery also inevitably has many shortcomings, most of the new battery production and processing cost is high, raw material acquisition difficulty is high, waste utilization rate is low, manufacturing difficulty is high, the process flow line is complex, and so on, and in the study of the new battery in electric vehicles, aerospace, solar panels and daily life after the application of the new battery speculated that the future development prospects of the new battery is very broad. Although there are many problems with new batteries that can not be solved, the future will slowly replace the status of traditional batteries, and finally understand that new batteries will have a positive effect on the development of human beings.

In recent years, the damaging effects of burning fossil fuels on the environment and petrol has started to decline, the demand for sustainable energy has risen sharply, and lithium electronic batteries have become a hot spot today due to their high specific capacity, high self-discharge rate, long life and high safety performance. Since lithium metal is an active metal, its preparation and preservation have high requirements on the environment. This paper discusses the development history, working principle, classification and practical application of lithium electronic batteries in real life. The two types of lithium batteries are called lithium metal batteries and lithium ion batteries, respectively. The battery of lithium electronic battery is composed of positive electrode, diaphragm, organic electrolyte, battery shell and negative electrode. Rechargeable battery is also called “lithium ion". Its working principle is to cycle lithium ion back and forth between positive and negative electrodes, and to add and reuse lithium ion alternately and continuously between positive and negative electrodes during charge and discharge. There are basically three categories of lithium-ion battery electrolyte: liquid, solid and molten salt. At present, lithium iron phosphate or frequently used nickel-manganese-cobalt ternary materials are employed as the cathode of standard goods., and negative electrode is mainly graphite and other carbon materials. A better study could result from a deeper understanding of lithium-ion batteries, providing a wealth of theoretical knowledge for in-depth research.

With the concept of carbon neutrality and carbon emissions peak, the Chinese government emphasize the importance of the application of renewable energy like photovoltaic energy. Internationally, some countries and regions already have ability to replace fossil energy with renewable resources such as wind, solar, wind, and hydrogen energy. This thesis focuses on photovoltaic energy and its applications. Photovoltaic energy usually uses monocrystalline silicon and polysilicon as raw materials, and this paper compares the advantages and disadvantages of both raw materials. The technology of building PV integration, which combines PV cells with buildings, and the technology that increases the conversion efficiency of PV cells by passivating the back contact of the emitting area are described in detail. In addition, this study illustrates the reasons that limit the development of photovoltaic cells under the current technology in terms of both self-factors and environmental factors. The self-factors are mainly the conversion rate of its own materials and energy consumption of meta-components, and the environmental factors are mainly the geographical location leading to the solar altitude angle and the amount of solar radiation. In the future, the global PV market will continue to maintain a rapid growth trend, driven by favorable factors such as the continued decline in the cost of photovoltaic power generation and the positive market orientation.

Graphene is the single layer of carbon atoms, which shows extraordinary electrical, mechanical, thermal, and optical capabilities. This research summarizes recent advances in applying graphene for energy storage, environmental engineering, and electronic devices. The two common synthetization approaches of graphene, top-down and bottom-up are illustrated. Graphene enhances lithium-ion batteries and supercapacitors as electrode materials due to its excellent physical and chemical properties such as high surface area and conductivity. The preparation methods of the graphene used in electrodes are shared. It removes both inorganic and organic pollutants from water through adsorption. As a printed 3D scaffold, graphene effectively absorbs gaseous pollutants. Graphene nanostructures improve the sensitivity of the biosensors: fluorescence sensors, electrochemical sensors, the surface plasmon resonance (SPR) sensors, the surface enhanced Raman scattering sensors. Highly conducting graphene paper can replace metals in flexible antennas. Graphene-metal nanocomposites transfer heat efficiently and cool electronics when dispersed in fluids. The multifunctionality and sustainability of graphene materials hold promise for nextgeneration technologies.

Organochlorine pollutants are a class of compounds formed by combining chlorine atoms with carbon atoms, and common organochlorine pollutants include chloroform and hexachlorocyclohexane. These compounds are persistent and difficult to degrade, so they exist in the environment for a long time. Organochlorine pollutants pose serious hazards to both humans and the environment. As a result, reducing the release of organochlorine pollutants and strengthening monitoring are important measures to protect the environment and human health. Treatment methods for organochlorine pollutants include physical methods such as adsorption and membrane separation, chemical methods such as oxidation, reduction and hydrolysis, and biological treatment methods such as microbial degradation and biosorption. Treatment of organochlorine pollution has great benefits. Treatment of organochlorine pollution can reduce the harm caused by these pollutants to the environment, improve the quality of water and air, and reduce the hazards of human health. This paper will first discuss what organochlorines are, the types of organochlorines, and the hazards of organochlorines, then discuss how to detect organochlorine residues in water, soil, and air, and finally propose specific methods for dealing with organochlorines and remediation programs for organochlorine pollution in water and soil.