Devices and Methods of Measurements最新文献

{"title":"Output Characteristics of Graphene Field Effect Transistors","authors":"V. N. Mishchenka","doi":"10.21122/2220-9506-2020-11-4-298-304","DOIUrl":"https://doi.org/10.21122/2220-9506-2020-11-4-298-304","url":null,"abstract":"The use of graphene, which has high mobility of charge carriers, high thermal conductivity and a number of other positive properties, is promising for the creation of new semiconductor devices with good output characteristics. The aim was to simulate the output characteristics of field effect transistors containing graphene using the Monte-Carlo method and the Poisson equation.Two semiconductor structures in which a single layer (or monolayer) of graphene is placed on a substrate formed from 6H-SiC silicon carbide material are considered. The peculiarity of the first of them is that the contact areas of drain and source were completely located on the graphene layer, the length of which along the longitudinal coordinate was equal to the length of the substrate. The second structure differed in that the length of the graphene layer was shortened and the drain and source areas were partly located on the graphene layer and partly on the substrate.The main output characteristics of field-effect transistors based on the two semiconductor structures considered were obtained by modeling. The modeling was performed using the statistical Monte Carlo method. To perform the simulation, a computational algorithm was developed and a program of numerical simulation using the Monte-Carlo method in three-dimensional space using the Poisson equation was compiled and debugged.The results of the studies show that the development of field-effect transistors using graphene layers can improve the output characteristics – to increase the output current and transconductance, as well as the limit frequency of semiconductor structures in high frequency ranges.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89918004","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}

{"title":"Methodology of Defining of the Radiation Therapy Components for Various Methods of Patients’ Treating Using Medical Linear Accelerators and Gamma-Therapeutic Devices","authors":"E. Titovich, M. Piatkevich, N. Makarava","doi":"10.21122/2220-9506-2020-11-4-289-297","DOIUrl":"https://doi.org/10.21122/2220-9506-2020-11-4-289-297","url":null,"abstract":"One of the main factors affecting the effectiveness of radiation therapy is the constancy of the patient’s position on the treatment table created by immobilization devices of various designs and held throughout the entire irradiation procedure, which guarantees the accuracy of the delivery of the prescribed dose distribution. The purpose of the work was to establish the numerical values of the dominant components of a radiation therapy session for each of the irradiation techniques most commonly used in clinical practice of the radiation therapy.To determine the numerical values of the components of the radiation therapy session, the authors have measured each component for some clinical cases of patients’ irradiation placed. The patients had been diagnosed with the following malignant tumours: prostate cancer, breast cancer, lung cancer, head and neck tumours. More than 2000 individual measurements have been carried out with the help of such medical linear accelerators as \"Clinac\", \"Unique\", \"Truebeam\", and the gamma-therapeutic apparatus named \"Theratron\".The numerical values of the time spent on 3 groups of parameters of an irradiation session were established: the mechanical parameters of the radiation therapy equipment, the functional characteristics of the irradiation systems and the parameters that directly depend on the personnel involved in an irradiation procedure.According to the measurement results, the flow diagram for the procedures of verifying a patient’s position on the therapeutic table (2 different techniques), preceding their irradiation and the radiation therapy procedures themselves was proposed. It has been shown that a number of session components can run in parallel to each other thus optimizing the time spent by a patient in the treatment room.Using the obtained values of the time spent on the radiation session parameters it is possible to actualize the mathematical model that will allow the medical physicist to determine in advance the duration of the irradiation session at the stage of treatment planning and choose a radiation therapy technique taking into account the individual parameters of the irradiation session in each particular clinical case.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78173194","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}

{"title":"Smartphone-Based Automated Non-Destructive Testing Devices","authors":"V. Petryk, A. Protasov, R. Galagan, A. Muraviov, I. Lysenko","doi":"10.21122/2220-9506-2020-11-4-272-278","DOIUrl":"https://doi.org/10.21122/2220-9506-2020-11-4-272-278","url":null,"abstract":"Currently, non-destructive testing is an interdisciplinary field of science and technology that serves to ensure the safe functioning of complex technical systems in the face of multifactorial risks. In this regard, there is a need to consider new information technologies based on intellectual perception, recognition technology, and general network integration. The purpose of this work was to develop an ultrasonic flaw detector, which uses a smartphone to process the test results, as well as transfer them directly to an powerful information processing center, or to a cloud storage to share operational information with specialists from anywhere in the world.The proposed flaw detector consists of a sensor unit and a smartphone. The exchange of information between the sensor and the smartphone takes place using wireless networks that use \"bluetooth\" technology. To ensure the operation of the smartphone in the ultrasonic flaw detector mode, the smartphone has software installed that runs in the Android operating system and implements the proposed algorithm of the device, and can serve as a repeater for processing data over a considerable distance (up to hundreds and thousands of kilometers) if it necessary.The experimental data comparative analysis of the developed device with the Einstein-II flaw detector from Modsonic (India) and the TS-2028H+ flaw detector from Tru-Test (New Zealand) showed that the proposed device is not inferior to them in terms of such characteristics as the range of measured thicknesses, the relative error in determining the depth defect and the object thickness. When measuring small thicknesses from 5 to 10 mm, the proposed device even surpasses them, providing a relative measurement error of the order of 1 %, while analogues give this error within 2–3 %.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78392791","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}

{"title":"In-Band Pumped Continuous-Wave Lasers Based on Ho:KY(WO4)2 Crystal and Ho:KGdYbY(WO4)2 Epitaxial Layer","authors":"O. Dernovich, N. V. Gusakovа, V. Kisel, A. Kravtsov, S. Guretsky, A. Pavlyuk, N. Kuleshov","doi":"10.21122/2220-9506-2020-11-4-264-271","DOIUrl":"https://doi.org/10.21122/2220-9506-2020-11-4-264-271","url":null,"abstract":"2 μm lasers are in demand for a number of practical applications, such as environmental monitoring, remote sensing, medicine, material processing, and are also used as a pump sources for optical parametric generators. Crystals of double potassium tungstates doped with ions of rare-earth elements were shown to be promising materials both for  the  creation  of  classical  solid-state  lasers  and  waveguide  lasers. The aim of this work was to develop a tunable pump laser in the spectral region of 1.9 µm based on double tungstate crystals doped with thulium ions and to study the lasing characteristics of a Ho:KY(WO4)2 crystal and a Ho:KGdYbY(WO4)2 single-crystal epitaxial layer under in-band pumping.With a Ho(1at.%):KY(WO4)2  crystal, continuous wave low-threshold lasing with an output power of 85 mW with a slope efficiency of 54 % at 2074 nm was achieved. For the first time to our knowledge, continuous wave laser  generation  in  a  waveguide  configuration  is  realized  in  a  single-crystal  layer of potassium tungstate doped with holmium ions grown by liquid-phase epitaxy. The maximum output power at a wavelength of 2055 nm was 16.5 mW.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79319174","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}

{"title":"Implementation of the Spectral Method for Determining of Measuring Instruments' Dynamic Characteristics","authors":"A. F. Sabitov, I. A. Safina","doi":"10.21122/2220-9506-2020-11-2-155-162","DOIUrl":"https://doi.org/10.21122/2220-9506-2020-11-2-155-162","url":null,"abstract":"The spectral method for establishing dynamic response of measuring instruments basically requires determining the amplitude spectrum of the signal in its informative part that includes the amplitude spectrum at zero frequency. The operating frequency range of existing low-frequency spectrum analyzers is above zero frequency that leads to an uncertainty in dynamic response of measuring instruments determined by the spectral method. The purpose of this paper is to develop a program for calculating the signal amplitude spectrum, starting from zero frequency, to implement a spectral method for determining the dynamic response of measuring instruments on computers equipped with the MatLab package.To implement the spectral method for determining the dynamic response of measuring instruments, we developed a program in the MatLab 2013b environment that determines the signal amplitude spectrum from zero Hertz. The program reads the source data from Excel tables and presents the calculated amplitude spectrum as a chart and a report table.It is shown that the developed program calculates the signal amplitude spectrum with a standard deviation of not more than 3.4 % in the frequency range of 0 to 10 rad/s. The calculated amplitude spectrum allows determining the time constant of first-order aperiodic measuring instruments with an uncertainty of not more than 0.166 % at any noise level, if their frequencies are outside the information part of the spectrum.We demonstrated the claimed advantage of the spectral method for determining dynamic response using the developed program by the example of a high-frequency noise in the transient response of some measuring instruments.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88385503","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}

{"title":"Method of Achieving the Least Loss of Information in an Asynchronous Binary Single-Photon Communication Channel with a Receiver Based on a Photon Counter","authors":"A. M. Timofeev","doi":"10.21122/2220-9506-2020-11-1-70-81","DOIUrl":"https://doi.org/10.21122/2220-9506-2020-11-1-70-81","url":null,"abstract":"A mathematical model of asynchronous optical communication channel with a photon counter applied as a receiving module has been built. The expression for calculating of data throughput of this channel has been obtained. As a result of implemented experimental investigations it has been established that the data throughput of asynchronous optical communication channel containing a photon counter on the basis of avalanche photodetector as a receiving module depends on optical radiation and photodetector supply voltage.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90122425","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}

{"title":"Technique for Studying of the Dynamics of Changes of a Smoky Environment Parameters during the Transition of Pyrolysis to Flame Combustion","authors":"A. A. Antoshyn, V. I. Nikitin","doi":"10.21122/2220-9506-2019-10-4-382-390","DOIUrl":"https://doi.org/10.21122/2220-9506-2019-10-4-382-390","url":null,"abstract":"The existing methods for monitoring the performance of multi-criteria fire detectors do not provide for verification of their characteristics in the conditions of transition from smoldering to flame burning. The aim of the work is the development of the research methods of the environmental parameters during the transition from smoldering (pyrolysis) to flame combustion for simulation a test fire while checking the quality of multi-criteria fire detectors.A technique to conduct research of environmental parameters under conditions of heating wood samples of different sizes to a temperature of selfignition and burning crumpled and smooth paper has been developed.Changes in the concentration of carbon monoxide, specific optical density, and scattering ability during the transition from smoldering (pyrolysis) to flame burning of prepared wood and crumpled paper were studied for the first time.It is shown that the controlled environmental parameters during the transition from smoldering pyrolysis to flame burning change together. Conclusion: the speed of growth of the scattering ability of smoke decreases by 2.4 times, the speed of increase in the specific optical density and concentration of carbon monoxide increases by 2 and 5.3 times (respec-tively), during the transition from pyrolysis to flame burning of wood.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76685360","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}

{"title":"Application of Satellite Image Processing Methods for Hydrocarbon Field Search","authors":"R. V. Fiodоrtsev, A. R. S. Cuenca, D. Kozhevnikov, V. Medina, R. Delgado","doi":"10.21122/2220-9506-2019-10-4-373-381","DOIUrl":"https://doi.org/10.21122/2220-9506-2019-10-4-373-381","url":null,"abstract":"The object of the study is software methods of the Earth surface images processing obtained from the VRSS-2 satellite to determine the spectral composition of the vegetation cover to detect the presence of carotenoids during prolonged exposure to hydrocarbons.The photosynthetic pigments of higher plants (chlorophylls, carotenoids and phytobiliproteins) were analyzed. In the chloroplasts of higher plants, chlorophyll and carotenoids are present in a ratio of about 3:1. The presence of hydrocarbons increases the amount of carotenoids. Carotenoids have absorption bands in the blue-violet region from 400 to 500 nm and a high reflection coefficient in the red-orange and yellow spectral regions, which corresponds to the multispectral MSS operating mode (B2) of the VRSS-2 satellite camera. An analysis of the vegetation growing in the study area of the Puerto Kumarebo settlement showed that the best indicator of the presence of hydrocarbons in the soil is Prosopis juliflora – CUJI with a deep root system of up to 50 m, growing in the study area.Using ENVI software, a comparative evaluation of the efficiency of photographs image processing was carried out using the normalized relative vegetation index (NDVI) and the structure-insensitive pigment index (SIPI) to detect changes in the color of green vegetation. It has been established that the SIPI index is more applicable for hydrocarbon search tasks. Moreover, the recorded index fluctuations in the area of uniform vegetation at the level of 2.5 % are characteristic of normal growing conditions and cannot serve as evidence of the presence of factors indicating the presence of hydrocarbons in the soil. For a more detailed assessment of the presence of carotenoids in the foliage and the presence of hydrocarbons in the soil, photographs with high optical resolution of objects on the surface are required.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91124350","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}

{"title":"Effect of Hole Extraction from the Base Region of a Silicon p–n–p Transistor on its Reactive Impedance","authors":"N. Gorbachuk, N. Poklonski, Ya. N. Marochkina, S. V. Shpakovski","doi":"10.21122/2220-9506-2019-10-4-322-330","DOIUrl":"https://doi.org/10.21122/2220-9506-2019-10-4-322-330","url":null,"abstract":"Transistor structures are the basic elements of integrated circuitry and are often used to create not only transistors themselves, but also diodes, resistors, and capacitors. Determining the mechanism of the occurrence of inductive type impedance in semiconductor structures is an urgent task, the solution of which will create the prerequisites for the development of solid-state analogs of inductors. The purpose of the work is to establish the effect of extraction of non-equilibrium charge carriers from the base region on the reactive impedance of a bipolar p–n–p transistor.Using impedance spectroscopy in the frequency range 20 Hz–30 MHz, the structures based on p–n–p transistors KT814G manufactured by JSC “INTEGRAL” were studied. It is shown that in the transistor structures it is possible to observe the “effect of negative capacitance” (inductive type impedance). It is established that the most probable cause of the inductive type impedance is the accumulation of uncompensated charge of holes in the base, the value of inductive impedance is influenced by both the injection efficiency in the base–emitter junction and the extraction efficiency in the base–collector junction.The results can be applied in the elaboration of technologies for the formation of elements of silicon based integrated circuits with an impedance of inductive type.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79214953","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}

{"title":"Scattering of Elastic Waves by an Inhomogeneous Boundary in the Acoustic Testing of Permanent Joints","authors":"А. Р. Баев, Н. В. Левкович, А. Л. Майоров, М. В. Асадчая","doi":"10.21122/2220-9506-2019-10-4-360-372","DOIUrl":"https://doi.org/10.21122/2220-9506-2019-10-4-360-372","url":null,"abstract":"Improving the reliability and testing performance of permanent joints оf different materials made by welding, spraying, gluing, soldering and other methods is an important production task, for which the ultrasonic method is the simplest and most effective. The purpose of this work was to expand the technical possibilities and increase the sensitivity of ultrasonic testing of adhesion defects of materials joints based on the establishment of laws governing the formation of a scattering field of elastic waves from an inhomogeneous boundary in three-dimensional space and issuing recommendations for the development of suggested method.For the first time, in the framework of classical concepts, the scattering fields of elastic waves of an acoustic beam with a circular cross section moving across the boundary of a semi-infinite defect are calculated. It is proposed to use a phase shift between the waves reflected from the indicated surfaces, which varies in the range of π/4–π, as an important parameter of the material joint's defect. It has a significant effect on the field pattern and its angular amplitude extrema — minima and maxima of different orders when the defect boundary is moved relative to the center of the acoustic beam spot.The features of the evolution of the structure of the scattering field are established, which make it possible to identify optimal conditions for the detection of weakly reflective defects in sound. It is shown that it is possible in principle to estimate the defect's area by measuring a change in the amplitude of the primary maximum of the radiation pattern of the scattered waves.Specific examples show the effectiveness of using the proposed method for a number of practical applications.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74267221","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}