Latvian Journal of Physics and Technical Sciences最新文献_第3页

Sodium Citrate and Polyvinylpyrrolidone Captured Silver Nanoparticles Transfer to Organic Solvents 柠檬酸钠和聚乙烯吡咯烷酮捕获的银纳米粒子向有机溶剂转移

IF 0.6

Latvian Journal of Physics and Technical Sciences Pub Date : 2024-02-01 DOI: 10.2478/lpts-2024-0003

J. Mikelsone, A. Vembris

{"title":"Sodium Citrate and Polyvinylpyrrolidone Captured Silver Nanoparticles Transfer to Organic Solvents","authors":"J. Mikelsone, A. Vembris","doi":"10.2478/lpts-2024-0003","DOIUrl":"https://doi.org/10.2478/lpts-2024-0003","url":null,"abstract":"\u0000 Silver nanoparticles (NPs) have gathered extensive attention due to their properties – chemical stability, good conductivity, catalytic activity, and antimicrobial activity. This makes NPs suitable for potential applications in the development of new technologies in the field of photonics, electronics, medicine, biochemical sensing, and imaging. Nanoprisms have local surface plasmon resonance starting from visible to near infra-red spectrum, broadening the possibilities of their applications. Ag NPs typically are synthesized in aqueous solution but the handling of NPs often requires their dispersion into nonpolar solvents and their mixing with organic compounds. Thus, nanoparticle transfer to organic media is essential for application in the field of emission enhancement due to NPs – organic semiconductor interaction. A shell changing method for NP tranfer was successfully used with a high transfer rate, but rather low stability. The previously proposed sonochemical method for NP transfer from aqueous to organic polymeric media is extended to different organic solvents. The ultrasonic method is suitable to obtain stable NPs in both organic solvent and organic solvent/organic compound solutions, and it can be stored at ambient conditions for at least several months. Transfer efficiency is suficient and NPs remain stable in an organic solvent like chlorobenzene, anisole, dichloromethane. The method has potential in NPs containing thin film preparation because sonication prevents the agglomeration of clusters.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139820920","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

Compensation of Accuracy Error for Time Interval Measurements 补偿时间间隔测量的精度误差

IF 0.6

Latvian Journal of Physics and Technical Sciences Pub Date : 2024-02-01 DOI: 10.2478/lpts-2024-0005

V. Bespal’ko, A. Litvinenko, V. Stepanovs, V. Kurtenoks, V. Smetska, V. Lapkovskis

{"title":"Compensation of Accuracy Error for Time Interval Measurements","authors":"V. Bespal’ko, A. Litvinenko, V. Stepanovs, V. Kurtenoks, V. Smetska, V. Lapkovskis","doi":"10.2478/lpts-2024-0005","DOIUrl":"https://doi.org/10.2478/lpts-2024-0005","url":null,"abstract":"\u0000 A method of accuracy error compensation for the time interval is examined, allowing to decrease the dependence of accuracy error on the duration of measured intervals and minimising the influence of destabilising factors – ambient temperature changes and the initial deviation of the meter clock generator frequency from the nominal value. The compensation method is based on a calibration procedure that measures precise time intervals under conditions of changing ambient temperature. Then the dependence of the accuracy error on temperature for a particular meter is recorded. Based on these data, a correction table is compiled containing correction factors and temperature values at which these factors were determined. Under real measurement conditions, the correction factor corresponding to the current temperature is determined from the table for measured result correction. The table with correction factor values could be stored in the memory of the meter or processing computer. Experimental verification of the method showed that applying a correction for a meter with a standard XO class clock generator (certificated instability of ±50 ppm) could obtain an equivalent clock generator instability of ±0.15 ppm. The application of the method is efficient in cases where the use of high-end clocking to ensure the required measurement accuracy is not economically feasible.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139883105","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

Charge Assessment for Nitrate-Based Salt as a Phase Change Material for a Medium-Temperature Latent Storage Tank 将硝酸盐作为相变材料用于中温潜热式储罐的电荷评估

IF 0.6

Latvian Journal of Physics and Technical Sciences Pub Date : 2024-02-01 DOI: 10.2478/lpts-2024-0006

Ismail, Y. I. Widodo, R. A. Rahman

{"title":"Charge Assessment for Nitrate-Based Salt as a Phase Change Material for a Medium-Temperature Latent Storage Tank","authors":"Ismail, Y. I. Widodo, R. A. Rahman","doi":"10.2478/lpts-2024-0006","DOIUrl":"https://doi.org/10.2478/lpts-2024-0006","url":null,"abstract":"\u0000 The present study assesses the heat characteristic of the nitrate-salt mixture as a phase change material (PCM) for a medium-temperature latent storage system (LSS). Two binary and ternary mixtures are evaluated, which demonstrate different thermal behaviour. The highest melting and latent heat capacity is obtained by KNO3(0.4)/NaNO3(0.6) at 223.8 °C and 161.5 J/g. However, it has a higher supercooling degree with a partial phase transition between 217.6 °C and 251.5 °C, making it unfeasible for a medium-temperature LSS tank. The ternary mixture (TM) with NaNO2(0.4)/KNO2(0.53)/NaNO3(0.7) demonstrates a stable phase transition with minimum partial phase transition (22.1 °C) and suitable heat of fusion (98.1 J/g). Further evaluation through static thermal profiling demonstrates that the TM has a notable performance during solid-sensible charge with a charge level indicator (CLI) around 45.3 %–49.1 %. The TM can be charged up to 85.7 % until the end stage of the phase transition. It promotes a better storage capacity with suitable performance since the system can be charged effectively at a suitable temperature range (< 160 °C) for various applications. The micrograph observation indicates some dispersed particles and local agglomeration, which makes phase stabilization as an advantageous method to promote a stable phase change process. The TM can be considered a suitable PCM for a medium-temperature LSS tank that allows for a better solar thermal renewable system operation.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139883625","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

General and Complete Synchronization of Mutual Coupling System of Quantum Dot Semiconductor Lasers With Optical Feedback 带光反馈的量子点半导体激光器相互耦合系统的一般和完全同步化

IF 0.6

Latvian Journal of Physics and Technical Sciences Pub Date : 2024-02-01 DOI: 10.2478/lpts-2024-0007

O. H. Abdulkareem, R. H. Abdali, B. A. Ghalib

引用次数: 0

Exposure Buildup Factors in Concrete, Lead for Point Isotropic and Unidirectional Photon Sources in the Energy Range from 10 to 50 MeV 10 至 50 MeV 能量范围内各向同性点光子源和单向光子源在混凝土、铅中的辐照堆积因子

IF 0.6

Latvian Journal of Physics and Technical Sciences Pub Date : 2024-02-01 DOI: 10.2478/lpts-2024-0002

I. Alhagaish, A. K. Aqili

引用次数: 0

A Practical Solution to Reduce Interference from Led Lights 减少 LED 灯干扰的实用解决方案

IF 0.6

Latvian Journal of Physics and Technical Sciences Pub Date : 2024-02-01 DOI: 10.2478/lpts-2024-0004

J. Kallunki

{"title":"A Practical Solution to Reduce Interference from Led Lights","authors":"J. Kallunki","doi":"10.2478/lpts-2024-0004","DOIUrl":"https://doi.org/10.2478/lpts-2024-0004","url":null,"abstract":"\u0000 The study explores the detection of a harmful, wide-band interference signal, whose origin is a traditional desk LED (light-emitting diode) lamp. The interference signal was noticed on the sensitive solar spectrometer observing system, which was operating at a frequency range between 100 and 300 MHz. The interference signal was so strong and wide-band that it destroyed totally the solar observations. The study introduces two practical EMI (Electromagnetic Interference) reducing methods: ferrite cores and shielding (shielding effectiveness, S.E.). Their theoretical background is presented, and, in addition, these methods are tested in practice. The measurements and tests showed that even simple ferrite core was a very effective method to reduce interference effects. It is important that a suitable setup will be found: a single ferrite core cannot solve a whole problem. This interference problem is very demonstrative and it can be used in educational purposes at an undergraduate level at Metropolia University of Applied Sciences, Finland. This study reveals the fact that standard lamps, which are on the market, do not necessarily follow good EMC (Electromagnetic Compatibility) practices.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139815918","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

Charge Assessment for Nitrate-Based Salt as a Phase Change Material for a Medium-Temperature Latent Storage Tank 将硝酸盐作为相变材料用于中温潜热式储罐的电荷评估

IF 0.6

Latvian Journal of Physics and Technical Sciences Pub Date : 2024-02-01 DOI: 10.2478/lpts-2024-0006

Ismail, Y. I. Widodo, R. A. Rahman

{"title":"Charge Assessment for Nitrate-Based Salt as a Phase Change Material for a Medium-Temperature Latent Storage Tank","authors":"Ismail, Y. I. Widodo, R. A. Rahman","doi":"10.2478/lpts-2024-0006","DOIUrl":"https://doi.org/10.2478/lpts-2024-0006","url":null,"abstract":"\u0000 The present study assesses the heat characteristic of the nitrate-salt mixture as a phase change material (PCM) for a medium-temperature latent storage system (LSS). Two binary and ternary mixtures are evaluated, which demonstrate different thermal behaviour. The highest melting and latent heat capacity is obtained by KNO3(0.4)/NaNO3(0.6) at 223.8 °C and 161.5 J/g. However, it has a higher supercooling degree with a partial phase transition between 217.6 °C and 251.5 °C, making it unfeasible for a medium-temperature LSS tank. The ternary mixture (TM) with NaNO2(0.4)/KNO2(0.53)/NaNO3(0.7) demonstrates a stable phase transition with minimum partial phase transition (22.1 °C) and suitable heat of fusion (98.1 J/g). Further evaluation through static thermal profiling demonstrates that the TM has a notable performance during solid-sensible charge with a charge level indicator (CLI) around 45.3 %–49.1 %. The TM can be charged up to 85.7 % until the end stage of the phase transition. It promotes a better storage capacity with suitable performance since the system can be charged effectively at a suitable temperature range (< 160 °C) for various applications. The micrograph observation indicates some dispersed particles and local agglomeration, which makes phase stabilization as an advantageous method to promote a stable phase change process. The TM can be considered a suitable PCM for a medium-temperature LSS tank that allows for a better solar thermal renewable system operation.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139823919","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

High Resolution Quadrupole Mass Spectrometer for Ion Beam Processing 用于离子束处理的高分辨率四极杆质谱仪

IF 0.6

Latvian Journal of Physics and Technical Sciences Pub Date : 2024-02-01 DOI: 10.2478/lpts-2024-0001

J. Blahins, A. Bzhishkian

引用次数: 0

Compensation of Accuracy Error for Time Interval Measurements 补偿时间间隔测量的精度误差

IF 0.6

Latvian Journal of Physics and Technical Sciences Pub Date : 2024-02-01 DOI: 10.2478/lpts-2024-0005

V. Bespal’ko, A. Litvinenko, V. Stepanovs, V. Kurtenoks, V. Smetska, V. Lapkovskis

{"title":"Compensation of Accuracy Error for Time Interval Measurements","authors":"V. Bespal’ko, A. Litvinenko, V. Stepanovs, V. Kurtenoks, V. Smetska, V. Lapkovskis","doi":"10.2478/lpts-2024-0005","DOIUrl":"https://doi.org/10.2478/lpts-2024-0005","url":null,"abstract":"\u0000 A method of accuracy error compensation for the time interval is examined, allowing to decrease the dependence of accuracy error on the duration of measured intervals and minimising the influence of destabilising factors – ambient temperature changes and the initial deviation of the meter clock generator frequency from the nominal value. The compensation method is based on a calibration procedure that measures precise time intervals under conditions of changing ambient temperature. Then the dependence of the accuracy error on temperature for a particular meter is recorded. Based on these data, a correction table is compiled containing correction factors and temperature values at which these factors were determined. Under real measurement conditions, the correction factor corresponding to the current temperature is determined from the table for measured result correction. The table with correction factor values could be stored in the memory of the meter or processing computer. Experimental verification of the method showed that applying a correction for a meter with a standard XO class clock generator (certificated instability of ±50 ppm) could obtain an equivalent clock generator instability of ±0.15 ppm. The application of the method is efficient in cases where the use of high-end clocking to ensure the required measurement accuracy is not economically feasible.","PeriodicalId":43603,"journal":{"name":"Latvian Journal of Physics and Technical Sciences","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139822974","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

High Resolution Quadrupole Mass Spectrometer for Ion Beam Processing 用于离子束处理的高分辨率四极杆质谱仪

IF 0.6

Latvian Journal of Physics and Technical Sciences Pub Date : 2024-02-01 DOI: 10.2478/lpts-2024-0001

J. Blahins, A. Bzhishkian

引用次数: 0