Devices and Methods of Measurements最新文献

{"title":"Analysis of Illumination Generated by LED Matrices Distribution","authors":"P. Bogdan, E. Zaytseva, P. O. Baranov, A. I. Stepanenko","doi":"10.21122/2220-9506-2022-13-1-60-67","DOIUrl":"https://doi.org/10.21122/2220-9506-2022-13-1-60-67","url":null,"abstract":"Сreation of indoor lighting systems with the possibility of changing its parameters in space and time is a promising direction within the framework of the intellectual environment system. The aim of this work was to create a methodology for calculating the illumination created by LED matrices which does not require the use of specialized software products and is adapted to the possibility of varying the parameters of LEDs and illuminated rooms.The urgency of creating a room lighting system that simulates the conditions of natural lighting taking into account the need to change its spectral composition in time, in space taking into account the physical and psychological state of a person is substantiated. The possibility of using well-known computer programs to calculate the distribution of illumination in the room is analyzed.A method has been developed for calculating the distribution of illumination on a plane using both a flat LED matrix and a matrix with an inclined arrangement of the planes of individual LEDs. It is shown that the distribution of illumination is a function of the indicatrix of the light intensity of the LED, its location in space, the number of LEDs in the matrix.Illumination distribution has been calculated for various light sources consisting of RGB LEDs both for desktop and ceiling lighting was calculated. It is established that when using matrices containing the same LEDs distribution of illumination is very nonuniform. The inclined arrangement of LED planes slightly increases uniformity reducing the maximum illumination. For ceiling lighting the option of uniform distribution of LEDs within the ceiling plane provides more uniform illumination than when the same number of LEDs are arranged in groups of matrices.Results of LED sources modeling indicate the need to modernize simple orthogonal matrices containing the same type of elements with the same power modes for all elements in order to increase the uniformity of illumination and efficiency. Such modernization can be carried out by changing the geometry of matrices differentiating the power modes of individual LEDs. The developed calculation program can be supplemented with options for introducing the above changes, as well as options for analyzing the spectral distribution of light in space. ","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":"31 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81227928","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":"Er3+,Yb3+:YGdSiO5 Crystal as Gain Media for Lasers Emitting in the Spectral Range of 1.5–1.6 µm","authors":"K. Gorbachenya, A. Yasukevich, V. Kisel, N. Tolstik, A. A. Tarachenko, V. I. Homan, L. Pavlovskiy, V. Orlovich, E. Volkova, V. Yapaskurt, N. Kuleshov","doi":"10.21122/2220-9506-2022-13-1-17-26","DOIUrl":"https://doi.org/10.21122/2220-9506-2022-13-1-17-26","url":null,"abstract":"Solid-state erbium lasers, emitting in the spectral range of 1.5–1.6 µm, are of great interest for several industrial applications. Nowadays the Er:glass is the most widespread laser material for obtaining laser radiation at the wavelength near 1.5 µm. However, the maximal output powers of such lasers are restricted by hundreds of milliwatts because low thermal characteristics of the glass host. By this reason the search for new crystalline hosts doped with erbium ions is the actual task.In this article the investigation results of spectroscopic properties of Er3+,Yb3+:YGdSiO5 (YGSO) crystals are reported. Polarized absorption and luminescence spectra were measured. The lifetimes of energy levels were determined. The excited state absorption spectra were measured. It was shown that excited state absorption band does not overlap with gain band in the range 1.5–1.6 µm. The energy transfer efficiency from ytterbium to erbium ions was estimated. The stimulated emission and gain cross-section spectra for Er3+ ions in YGSO were calculated.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":"9 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84626111","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":"Methods for Accuracy Increasing of Solid Brittle Materials Fracture Toughness Determining","authors":"V. Lapitskaya, T. Kuznetsova, S. Chizhik, B. Warcholiński","doi":"10.21122/2220-9506-2022-13-1-40-49","DOIUrl":"https://doi.org/10.21122/2220-9506-2022-13-1-40-49","url":null,"abstract":"Method for determining of the fracture toughness of brittle materials by indentation is described. The critical stress intensity factor KIC quantifies the fracture toughness. Methods were developed and applied to improve the accuracy of KIC determination due to atomic force microscopy and nanoindentation. It is necessary to accurately determine parameters and dimensions of the indentations and cracks formed around them in order to determine the KIC . Instead of classical optical and scanning electron microscopy an alternative high-resolution method of atomic force microscopy was proposed as an imaging method.Three methods of visualization were compared. Two types of crack opening were considered: along the width without vertical displacement of the material and along the height without opening along the width. Due to lack of contact with the surface of the samples under study, the methods of optical and scanning electron microscopy do not detect cracks with a height opening of less than 100 nm (for optical) and less than 40–50 nm (for scanning electron microscopy). Cracks with opening in width are determined within their resolution. Optical and scanning electron microscopy cannot provide accurate visualization of the deformation area and emerging cracks when applying small loads (less than 1.0 N). The use of atomic force microscopy leads to an increase in accuracy of determining of the length of the indent diagonal up to 9.0 % and of determining of the crack length up to 100 % compared to optical microscopy and up to 67 % compared to scanning electron microscopy. The method of atomic force microscopy due to spatial three-dimensional visualization and high accuracy (XY ± 0.2 nm, Z ± 0.03 nm) expands the possibilities of using indentation with low loads.A method was proposed for accuracy increasing of KIC determination by measuring of microhardness from a nanoindenter. It was established that nanoindentation leads to an increase in the accuracy of KIC determination by 16–23 % and eliminates the formation of microcracks in the indentation.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":"7 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75430244","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":"Assessing of a Radiation Therapy Sessionʼs Duration at the Stage of Pre-Radiation Preparation","authors":"M. Piatkevich, E. Titovich","doi":"10.21122/2220-9506-2022-13-1-68-73","DOIUrl":"https://doi.org/10.21122/2220-9506-2022-13-1-68-73","url":null,"abstract":"The treatment planning process includes a review of the radiation treatment plan which leads to a decision on the patientʼs treatment technique. The scope of this study was to create a mathematical model for calculating of a radiation therapy session duration during the pre-radiation planning stage.For dosimetric planning of radiation treatment the authors provided a formula and an algorithm for determining of a patientʼs irradiation session duration. Radiation therapy session parameters such as radiation technique, number of monitor units, characteristics of radiotherapy equipment, number of radiation fields, radiation field parameters (angles of rotation of the radiotherapy coach, collimator, gantry), presence / absence of dose-modulating devices, dose rate, and duration of patient position verification procedures have all been taken into account during the development of software. The developed application explains how to define typical timing characteristics for various items as well as how to select a template from a built-in drop-down menu. If the dosimetric plan does not match for one of the templates, the program provides a space for defining of all parameters manually.The anticipated deviations of the true indicators from the expected indicators of the duration of the radiation therapy session were assessed. A total of 300 cases have been completely measured, with 100 cases studied for each irradiation technique (IMRT, VMAT, 3D). The maximum detection confidence value for the 3DCRT irradiation technique is 2.3 %, while the deviation for the IMRT and VMAT irradiation techniques is less than 1 %. The magnitude and degree of the deviation of the measured value from the expected one for a variety of characteristics and features have been revealed to depend on the actions of the personnel.The program developed allows medical physicists to analyze the timing parameters of the specified dosimetric planning methodologies directly on the treatment planning workstation. Evaluation of the duration of a radiation therapy session during the treatment planning stage, selection of various radiation treatment modalities, and consideration of the characteristics of the radiation session in each clinical case are available for analysis and further justified action. ","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":"108 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79210301","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":"Determination of 238U Content by Gamma Radiation Emitting from 234mPa Radionuclide","authors":"A. Khruschinski, S. Kutsen, A. Zhukouski, Naoyuki Sugai, H. Sugai, Michinori Mogi","doi":"10.21122/2220-9506-2022-13-1-32-39","DOIUrl":"https://doi.org/10.21122/2220-9506-2022-13-1-32-39","url":null,"abstract":"Radionuclide 238U is one of the most important radioactive elements that must be controlled in nuclear power engineering, geological exploration, control of radioactive contamination of soils and raw materials used in construction. The most optimal way to control 238U is to use the 234mPa radionuclide, the activity of which, due to its short lifetime (≈ 1.2 min), is unambiguously related to the activity of 238U even if the secular equilibrium is disturbed in the sample under studyРossibility of use of the 234mPa nuclide gamma radiation to determine 238U with a scintillation detector in a medium containing natural radionuclides is investigated and demonstrated using the simplest examples. The proposed algorithm for determining of the 238U content is based on the Monte Carlo simulation of the detector response to the radiation of the 234mPa radionuclide at its 1001 keV energy line and subsequent processing of the experimental spectrum, including the Wiener filtering of the signal. This method makes it possible to determine the content of 238U in a continuous homogeneous medium while presence of natural radionuclides in it.The algorithm for determining of 238U content includes several main steps. Filtering based on the Wiener algorithm allows selecting a slowly changing part of the spectrum. Results of Monte Carlo simulations make it possible to determine the detection efficiency in a limited informative region of the spectrum, which includes, along with the 1001 keV peak from the 234mPa nuclide, which is a decay product of the radionuclide 234Th, and the peak of an interfering radionuclide from the decay chain of 232Th. This part of the spectrum does not contain any other lines of gamma radiation from natural radionuclides – decay products of both thorium and uranium chains. These two peaks in the spectral region under study can be separated from each other in a medium with a typical concentration of 234Th.Analysis of results of the activity of depleted uranium metal measuring in accordance with the proposed algorithm shows the possibility of determining of 238U content with an uncertainty of 3–5 %.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":"31 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78202196","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":"Devices and Methods for Measuring of the Ambient Air Dust. Short Review","authors":"N. Mukhurov, A. Khodin, Y. Kim","doi":"10.21122/2220-9506-2022-13-1-7-16","DOIUrl":"https://doi.org/10.21122/2220-9506-2022-13-1-7-16","url":null,"abstract":"The main characteristics of airborne micro/nanoparticles, their impact on human health and air quality standards are presented. International standards classify microparticles by size (PM10, PM2.5, PM1, UFP), establish maximum allowable concentrations and control methods. Particular attention is paid to carbonand virus-containing microparticles control. To monitor the air environment in enclosed spaces and in transport, the portable sensors of micro-, nanoparticles are required with the ability to classify them by size and electrophysical characteristics.Detection of microparticles includes the sorting of particles entering the sensor by size and material type, subsequent actual detection of particles of the same kind, with subsequent classification by size, electrical and morphological characteristics. Separation of nanoand microparticles by size before detection improves the sensitivity and selectivity of the detector both in size and material. The virtual impactor and dielectrophoresis method are considered for integration in a Lab-on-Chip type sensor. Detection of microparticles is performed by separating the dispersed phase from the aerosol followed by the analysis, or directly in the air flow. The classification of detection methods according to speed and functionality is given. Among the methods allowing detection of micrometer and submicrometer size particles, the most suitable for miniaturization and serial production of Lab-on-Chip sensors are the multi-wavelength photoelectric, MEMS, and capacitor elements.The microelectromechanics, microfluidics and microoptics technologies make it possible to create portable sensor systems of the Lab-on-Chip type to detect particulates matter of micrometer and submicrometer size. A micro-, nanoparticles detector prototype based on alumina technology using MEMS elements for a compact Lab-on-Chip type sensor is presented. The proposed design for multifunctional portable detector of airborne micro/nanoparticles is prospective for industry, transport, medicine, public and residential buildings applications.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":"184 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88471678","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 for Increasing of Lens Gluing Technological Process Efficiency and a Reliable Evaluation of Output Controlled Parameters","authors":"R. V. Fiodоrtsev, E. Metelskaya, V. A. Marchik, A. Kuznetsov, A. E. Makarevich","doi":"10.21122/2220-9506-2022-13-1-50-59","DOIUrl":"https://doi.org/10.21122/2220-9506-2022-13-1-50-59","url":null,"abstract":"The use of glued lens components in optical devices improves the image quality of telescopic and photographic lenses or inverting systems by eliminating a number of aberrations, and also reduces light losses in the optical system of the device. The traditional production process of lenses gluing involves the sequential execution of a set of technological operations and takes a significant period of time. The purpose of the research was to improve the accuracy and productivity of the technological process of lenses gluing by improving the optical system of the control and measuring device and automating the operation of lenses optical axes combining by introducing an electronic reference system and mechanisms for micro-movements of optical parts.A technique is proposed for centering of two and three-component optical blocks by an autocollimation flare which provides a matching accuracy of less than 0.5 μm. The possibility of constructive modernization of the classic ST-41 autocollimation microscope with parallel separation of the displayed output information in the visual and television channels is shown. An automated system for controlling of the process of convergence of autocollimation points in the device is proposed. Using software methods an electronic grid template is formed on the monitor screen, onto which images of autocollimation points are projected. The decentering value 2Δe is determined and a corrective control voltage is applied to three stepper motors and pushers for transverse movement of the glued optical part.Specialized software has been developed for automatically bringing the position of the autocollimating crosshair to the center of the measuring scale of the grid based on a combination of two methods of “least squares” and “successive approximation”. Compliance with a number of technological transitions and the accompanying control of geometric parameters make it possible to achieve greater accuracy in determining the eccentricity of the crosshairs of the aligned optical axes of the glued lenses. ","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":"1 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87295319","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":"Compact Passively Q-Switched Tm:KY(WO4)2 Laser","authors":"V. Kisel","doi":"10.21122/2220-9506-2022-13-1-27-31","DOIUrl":"https://doi.org/10.21122/2220-9506-2022-13-1-27-31","url":null,"abstract":"Diode-pumped thulium lasers emitting in the spectral range near 2 μm are attractive for applications in different areas: surgery, rangefinding, and environmental atmosphere monitoring. In this article the latest results of Tm:KYW laser performance with a polycrystalline Cr:ZnSe as the most available saturable absorber for 2 μm spectral region are presented.A maximum continuous-wave output power of ≈ 0.65 W with a slope efficiency of 55 % was obtained at the wavelength of 1940 nm. Laser pulses with energy of 26 μJ and repetiotion rate of 6 kHz coresponding to 156 mW of average output power at 1910 nm were obtained at 2.2 W of incident puwp power for the Cr:ZnSe saturable absorber with initial transmission of 95 %. By using of saturable absorber with lower initial transmission of 90 % laser pulses with energy of 40 μJ and duration as short as 10 ns were realized. The maximal pulse repetition rate was 2.8 kHz at incident pump power of 2.2 W.Based on the obtained results, it can be concluded that Tm:KYW crystals are promising active media for the compact passively Q-switched lasers emitting in the spectral range near 2 μm for the usage in surgery and rangefinding. Also, described laser is planned to be used as a laser source in laser-induced damage threshold measurements setup for investigation of damage threshold of saturable absorbers as well as nonlinear crystals at the wavelength near 2 μm.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":"125 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91051413","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":"Compositionally Disordered Doped with Cerium Crystalline Garnet Type Materials for Brighter and Faster Scintillations","authors":"M. Korzhik","doi":"10.21122/2220-9506-2021-12-4-280-285","DOIUrl":"https://doi.org/10.21122/2220-9506-2021-12-4-280-285","url":null,"abstract":"Ce-doped tetracationic garnets (Gd, M)3Al2Ga3O12(M = Y, Lu) form a family of new multipurpose promising scintillation materials. The aim of this work was to evaluate the scintillation yield in the materials of quaternary garnets activated by cerium ions with partial isovalent substitution of the matrix-forming gadolinium ions by yttrium or lutetium ions.Materials were obtained in the form of polycrystalline ceramic samples, and the best results were shown by samples obtained from the raw materials produced by the coprecipitation method. It was found that ceramics obtained from coprecipitated raw materials ensure a uniform distribution of activator ions in the multi-cationic matrices, which enables the high light yield and fast scintillation kinetics of the scintillation. It was demonstrated that the superstoichiometric content of lutetium/gadolinium in the material is an effective method to suppress phosphorescence accompanied scintillation. For ceramics with the composition (Gd, Lu)3Al2Ga3O12 , a scintillation yield of more than 50.000 ph/MeV was achieved. The scintillation kinetics was measured to be close to the kinetics with a decay constant of 50 ns.In terms of the set of the parameters, the developed scintillation materials are close to the recently developed alkali halide materials LaBr3:Ce, GdBr3:Ce. Moreover, they have high mechanical hardness, are characterized by the absence of hygroscopicity, and are better adapted to the manufacture of pixel detectors used in modern devices for medical diagnostics.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":"107 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73502201","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":"Autonomous Streaming Space Objects Detection Based on a Remote Optical System","authors":"V. Baranova, V. Saetchnikov, A. Spiridonov","doi":"10.21122/2220-9506-2021-12-4-272-279","DOIUrl":"https://doi.org/10.21122/2220-9506-2021-12-4-272-279","url":null,"abstract":"Traditional image processing techniques provide sustainable efficiency in the astrometry of deep space objects and in applied problems of determining the parameters of artificial satellite orbits. But the speed of the computing architecture and the functions of small optical systems are rapidly developing thus contribute to the use of a dynamic video stream for detecting and initializing space objects. The purpose of this paper is to automate the processing of optical measurement data during detecting space objects and numerical methods for the initial orbit determination.This article provided the implementation of a low-cost autonomous optical system for detecting of space objects with remote control elements. The basic algorithm model had developed and tested within the framework of remote control of a simplified optical system based on a Raspberry Pi 4 single-board computer with a modular camera. Under laboratory conditions, the satellite trajectory had simulated for an initial assessment of the compiled algorithmic modules of the computer vision library OpenCV.Based on the simulation results, dynamic detection of the International Space Station in real-time from the observation site with coordinates longitude 25o41′49″ East, latitude 53o52′36″ North in the interval 00:54:00–00:54:30 17.07.2021 (UTC + 03:00) had performed. The video processing result of the pass had demonstrated in the form of centroid coordinates of the International Space Station in the image plane with a timestamps interval of which is 0.2 s.This approach provides an autonomous raw data extraction of a space object for numerical methods for the initial determination of its orbit.","PeriodicalId":41798,"journal":{"name":"Devices and Methods of Measurements","volume":"27 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74301214","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}