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Latvian Journal of Physics and Technical Sciences最新文献

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Investigation of Cenosphere-Based Lightweight Ceramic Matrixless Syntactic Foam Through Spark Plasma Sintering 通过火花等离子烧结研究基于仙人球的轻质无基质陶瓷合成泡沫
IF 0.5
Latvian Journal of Physics and Technical Sciences Pub Date : 2024-07-18 DOI: 10.2478/lpts-2024-0026
T. Eiduks, R. Drunka, V. Abramovskis, I. Zalite, P. Gavrilovs, J. Baronins, V. Lapkovskis
{"title":"Investigation of Cenosphere-Based Lightweight Ceramic Matrixless Syntactic Foam Through Spark Plasma Sintering","authors":"T. Eiduks, R. Drunka, V. Abramovskis, I. Zalite, P. Gavrilovs, J. Baronins, V. Lapkovskis","doi":"10.2478/lpts-2024-0026","DOIUrl":"https://doi.org/10.2478/lpts-2024-0026","url":null,"abstract":"\u0000 The current study introduces porous ceramic materials fabricated from cenospheres through spark plasma sintering. The investigation delves into the impact of sintering temperature, mould diameter (20 and 30 mm), and cenosphere size on the resulting material properties. Notably, sample shrinkage initiates at 900 °C and demonstrates an upward trend with temperature escalation, while a larger mould diameter contributes to sample shrinkage. Elevated sintering temperature leads to increased apparent density across various sample series, such as CS 63–150 µm in a 20 mm mould (0.97 to 2.3 g/cm³ at 1050–1300 °C), CS 150–250 µm in a 20 mm mould (0.93 to 1.96 g/cm³ at 1050–1200 °C), and others in different mould sizes. Total porosity decreases from 61.5 % to 3.9 % with a rising sintering temperature (1050 to 1250 °C), while open porosity starts decreasing at lower temperatures. Closed porosity peaks in samples sintered at 1150 °C. Furthermore, an increase in sintering temperature from 1050 to 1300 °C boosts the compressive strength of CS 63–150 samples in a 20 mm mould from 11 MPa to 312 MPa. These findings align with the Rice model, illustrating an exponential relationship between compressive strength, material porosity, and fully dense material compressive strength.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141824399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A Technical and Economic Study of Sustainable Power Generation Backup 可持续备用发电的技术和经济研究
IF 0.5
Latvian Journal of Physics and Technical Sciences Pub Date : 2024-07-18 DOI: 10.2478/lpts-2024-0029
A. Backurs, L. Zemite, L. Jansons
{"title":"A Technical and Economic Study of Sustainable Power Generation Backup","authors":"A. Backurs, L. Zemite, L. Jansons","doi":"10.2478/lpts-2024-0029","DOIUrl":"https://doi.org/10.2478/lpts-2024-0029","url":null,"abstract":"\u0000 This study focuses on overview and general economic viability evaluation of four types of portable electric generators: diesel and petrol internal combustion engines, batteries/accumulators and inverter systems (especially lithium polymer and lithium-ion battery systems), hydrogen fuel cell systems and combination (hybrid) of the latter. It does not include the rarely used, inefficient forms of energy conversion, such as steam turbines, as well as energy generators that are difficult to adjust with consumption and supply variations (variable forms of RES like wind and solar energy). The main targets of the study are battery/inverter systems, hydrogen fuel cell systems, and hybrid battery/inverter and hydrogen fuel cell systems, with hydrogen fuel cell systems being the thematic core.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141824950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Experimental Study of a Solar Trigeneration System Prototype 太阳能热电联产系统原型的实验研究
IF 0.5
Latvian Journal of Physics and Technical Sciences Pub Date : 2024-07-18 DOI: 10.2478/lpts-2024-0028
A. Snegirjovs, G. Klavs
{"title":"Experimental Study of a Solar Trigeneration System Prototype","authors":"A. Snegirjovs, G. Klavs","doi":"10.2478/lpts-2024-0028","DOIUrl":"https://doi.org/10.2478/lpts-2024-0028","url":null,"abstract":"\u0000 A prototype solar trigeneration system was built in a new private single-family residential house for experimental purposes. The prototype system was designed to supply the building with the required thermal energy and cooling to a full extent. In addition, one of the conditions is that the thermal and the electrical energy generated by the solar systems should be used for the needs of the building to a maximum extent. The prototype system provides an opportunity to recover thermal energy both during the heating and the cooling season.\u0000 This article describes the prototype configuration, the first results of testing, analysis of the results obtained, and the operational features and shortcomings of the open system, as well as the possibilities for its improvement.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141827326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Smart Grid Standardisation: Contributions and Opportunities of EU Horizon 2020 Projects 智能电网标准化：欧盟地平线 2020 项目的贡献与机遇
IF 0.5
Latvian Journal of Physics and Technical Sciences Pub Date : 2024-07-18 DOI: 10.2478/lpts-2024-0025
Mutule, I. Antoskova, P. Carroll, C. Papadimitriou, A. Morch, V. Efthymiou
{"title":"Smart Grid Standardisation: Contributions and Opportunities of EU Horizon 2020 Projects","authors":"Mutule, I. Antoskova, P. Carroll, C. Papadimitriou, A. Morch, V. Efthymiou","doi":"10.2478/lpts-2024-0025","DOIUrl":"https://doi.org/10.2478/lpts-2024-0025","url":null,"abstract":"\u0000 Standards are critically important for smartening the grid because they affect the interoper-ability, compatibility, efficiency, and realisation of new technologies and services. In this paper we assess the contribution of EU funded Horizon 2020 projects to adapting or initiating new Smart Grid standards. We provide a comprehensive overview of the Smart Grid standardisation ecosystem and identify opportunities for researchers and innovators to participate in stan-dardisation activities. We identify 225 Horizon 2020 Smart Grid projects and explore which have contributed to the creation or revision of Smart Grid standards. We identify the type of standardisation activities undertaken and explore the factors that influence engagement. We have found that 21 % of EU Horizon 2020 Smart Grid projects engage in some level of standardisation activities. Of these projects the majority (60 %) are involved in understanding standards, 31 % actively engage in influencing standards, while 8 % successfully participate in elaborating new standards. Our study demonstrates that despite the complexity of the Smart Grid Standardisation ecosystem, EU funded researchers and innovators play an important role in the standardisation process.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141824867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Comparative Analysis of Thermal Characteristics: Virgin Polyacrylonitrile (PAN) Versus Electrospun Pan Nanofibre Mats 热特性比较分析：原生聚丙烯腈 (PAN) 与电纺泛纳米纤维垫的热特性对比分析
IF 0.5
Latvian Journal of Physics and Technical Sciences Pub Date : 2024-07-18 DOI: 10.2478/lpts-2024-0031
J. Sanchaniya
{"title":"Comparative Analysis of Thermal Characteristics: Virgin Polyacrylonitrile (PAN) Versus Electrospun Pan Nanofibre Mats","authors":"J. Sanchaniya","doi":"10.2478/lpts-2024-0031","DOIUrl":"https://doi.org/10.2478/lpts-2024-0031","url":null,"abstract":"\u0000 The utility of polymers in the fabrication of nanofibres via electrospinning is well established. Paramount to their application is understanding of their thermal properties, as these dictate not only their processability but also their mechanical robustness, stability under elevated temperatures, and suitability for intended applications. The electrospinning process, which involves heating polymers and subjecting them to high voltage, inherently modifies their thermal characteristics. This study attempts to elucidate these alterations, particularly by focusing on polyacrylonitrile (PAN) nanofibres. Employing techniques such as thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC), the study compares the thermal properties of electrospun PAN nanofibre mats with those of their virgin counterparts. The PAN nanofibres were synthesised by electrospinning the PAN polymer solution and collecting the resultant mat on a flat plate collector. For a comparative analysis, virgin PAN, from which nanofibres were derived, underwent identical thermal testing. The findings reveal a reduction in the glass transition temperature of PAN nanofibres by approximately 3–5 % compared to virgin PAN. In addition, a significant reduction in heat capacity of about 42 % was observed in the nanofibres. Additionally, the TGA results indicated solvent evaporation at approximately 110 °C. Therefore, this investigation sheds light on the nuanced alterations in the thermal characteristics of PAN nanofibre mats as a result of the electrospinning process, providing vital insights for their application in various thermal management scenarios.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141825711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Experimental Measurement of Working Parameters of Conical Electromagnetic Levitation Coils 锥形电磁引力线圈工作参数的实验测量
IF 0.5
Latvian Journal of Physics and Technical Sciences Pub Date : 2024-07-18 DOI: 10.2478/lpts-2024-0030
V. Silamiķelis, J. Snikeris, A. Apsītis, A. Pumpurs
{"title":"Experimental Measurement of Working Parameters of Conical Electromagnetic Levitation Coils","authors":"V. Silamiķelis, J. Snikeris, A. Apsītis, A. Pumpurs","doi":"10.2478/lpts-2024-0030","DOIUrl":"https://doi.org/10.2478/lpts-2024-0030","url":null,"abstract":"\u0000 Electromagnetic levitation (EML) is a promising technique allowing to melt various materials, including refractive metals, while avoiding physical contact between the molten material and components of the melting system, thus avoiding contamination of the molten material. EML coils act both as a container and a heating source for a conductive sample placed within it. EML systems are difficult to optimize for specific tasks and computational simulations are often used to aid the process. Development of simulations of EML processes is an ongoing field of research. Obtaining precise experimental measurement data of EML processes is important for development and verification of computational simulations. This study aims to provide experimental data of simultaneous measurements for magnetic field, Joule heating and lift force in different conical EML coils with a counterturn.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141827735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Characterisation of Hybrid Photodetector Signals for Satellite Laser Ranging Application 用于卫星激光测距的混合光电探测器信号特性分析
IF 0.5
Latvian Journal of Physics and Technical Sciences Pub Date : 2024-07-18 DOI: 10.2478/lpts-2024-0027
K. Salmins, J. Kaulins
{"title":"Characterisation of Hybrid Photodetector Signals for Satellite Laser Ranging Application","authors":"K. Salmins, J. Kaulins","doi":"10.2478/lpts-2024-0027","DOIUrl":"https://doi.org/10.2478/lpts-2024-0027","url":null,"abstract":"\u0000 The hybrid photodetector (HPD) is a photomultiplier tube combined with the semiconductor device within the vacuum. The photoelectrons emitted from the photocathode directly hit the semiconductor enabling efficient electron multiplication with low noise and symmetric output pulse. These properties make a hybrid photodetector a good solution for photon-counting applications. At the Satellite Laser Ranging Station of the Institute of Astronomy at the University of Latvia, the hybrid photodetector characteristics were evaluated for SLR applications, including multiphoton mode and time-walk compensation.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141824370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Implementation of Classical Motion Cueing Algorithms for Serial Manipulator Based Motion Simulator: Larrmos Case Study 为基于串行机械手的运动模拟器实现经典运动提示算法：Larrmos 案例研究
IF 0.5
Latvian Journal of Physics and Technical Sciences Pub Date : 2024-07-18 DOI: 10.2478/lpts-2024-0024
A. Stupāns, P. Maksimkins, A. Senfelds, L. Ribickis
{"title":"Implementation of Classical Motion Cueing Algorithms for Serial Manipulator Based Motion Simulator: Larrmos Case Study","authors":"A. Stupāns, P. Maksimkins, A. Senfelds, L. Ribickis","doi":"10.2478/lpts-2024-0024","DOIUrl":"https://doi.org/10.2478/lpts-2024-0024","url":null,"abstract":"\u0000 The study focuses on the development and evaluation of a motion control system for the Large Range Robotic Motion Simulator (LaRRMoS), which is based on a serial manipulator with 6 degrees-of-freedom. Two motion cueing algorithms (MCAs) – Classical Washout Filter (CWF) and Classical Washout Filter with Cylindrical coordinates (CYL) – are implemented and tested for simulation fidelity and LaRRMoS workspace utilization. CWF and CYL motion cueing performance gets assessed in two use cases: car simulation and luge sports simulation. The car case is a typical driving simulator application. The luge sports case is chosen for its high dynamics to assess the limits of the robot and motion cueing. Though this study uses a pre-recorded set of motion data and runs simulations in non-interactive mode, it aims for real-time interactive simulation for LaRRMoS in the future, so only MCAs capable of real-time operation are inspected. Conducted tests show that the CYL algorithm provides superior performance in highly dynamic motion replication, particularly in lateral accelerations.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141825745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Towards Scalable Synthesis of TiSe2 and VSe2 Thin Films 实现 TiSe2 和 VSe2 薄膜的规模化合成
IF 0.6
Latvian Journal of Physics and Technical Sciences Pub Date : 2024-03-30 DOI: 10.2478/lpts-2024-0009
K. Kadiwala, E. Dipans, L. Dipane, E. Butanovs, B. Polyakov
{"title":"Towards Scalable Synthesis of TiSe2 and VSe2 Thin Films","authors":"K. Kadiwala, E. Dipans, L. Dipane, E. Butanovs, B. Polyakov","doi":"10.2478/lpts-2024-0009","DOIUrl":"https://doi.org/10.2478/lpts-2024-0009","url":null,"abstract":"\u0000 Transition metal dichalcogenides (TMDs), specifically those involving V and Ti, possess fascinating material properties, making them interesting candidates for scientific studies. The existing growth methods of these materials are typically limited by scalability – either low yield or high cost. Here, we propose an alternative 2-step method valid for scalable production. In the first step, precursor films of Ti / V are deposited using magnetron sputtering, followed by the second step of selenization of these samples using elemental Se in a vacuum-sealed quartz ampoule for conversion to their respective diselenide material. Synthesized films are char-acterised using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and X-ray photoelectron (XPS). The method demonstrated here can be used to increase the active surface area of TiSe2 and VSe2 for their potential catalytic and HER applications using nanostructured substrates, while also providing an opportunity for scalable synthesis of films that can be extended to synthesize other TMDs as well.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140363618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Towards High-Precision Quadrotor Trajectory Following Capabilities: Modelling, Parameter Estimation, and LQR Control 实现高精度四旋翼飞行器轨迹跟踪能力：建模、参数估计和 LQR 控制
IF 0.6
Latvian Journal of Physics and Technical Sciences Pub Date : 2024-03-30 DOI: 10.2478/lpts-2024-0015
A. Hanif, I. E. Putro, A. Riyadl, O. Sudiana, Hakiki, H. Y. Irwanto
{"title":"Towards High-Precision Quadrotor Trajectory Following Capabilities: Modelling, Parameter Estimation, and LQR Control","authors":"A. Hanif, I. E. Putro, A. Riyadl, O. Sudiana, Hakiki, H. Y. Irwanto","doi":"10.2478/lpts-2024-0015","DOIUrl":"https://doi.org/10.2478/lpts-2024-0015","url":null,"abstract":"\u0000 Quadrotor unmanned aerial vehicles (UAVs) are small, agile four-rotor systems suitable for various applications, from surveillance to disaster support missions. Hence, achieving high-precision trajectory tracking is crucial for their successful deployment. This research focuses on modelling, parameter identification, and Linear Quadratic Regulator (LQR) control design for quadrotors, aiming to enhance their trajectory following capabilities. The quadrotor dynamics are a sixth degree-of-freedom (6DOF) equation of motion derived from Newton’s second law, encompassing moment of inertia, centre of gravity, weight, and thrust of propeller parameters. Experimental measurements are conducted to accurately determine these parameters, ensuring a realistic representation of the quadrotor system. Subsequently, a linearized model is constructed to provide a suitable plant for control system development. The LQR control design is intended to improve the trajectory tracking performance. This control strategy is validated through simulation and practical experiments, demonstrating its effectiveness in achieving high-precision trajectory following capabilites. The proposed approach demonstrates that LQR control effectively guides the quadrotor to resemble a predefined trajectory, experiencing only 3 % overshoot observed during the initial phase of flight.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140364095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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