Статті в журналах: "Primary measuring converter"

1

Solovev, Denis B., and Alena E. Merkusheva. "Novel Active Current Transducers for Diesel Power Stations." International Journal of Power Electronics and Drive Systems (IJPEDS) 7, no. 1 (March 1, 2016): 152. http://dx.doi.org/10.11591/ijpeds.v7.i1.pp152-158.

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Autonomous diesel power plants found the active application at the organization of autonomous power supply of the mining enterprises. In article the problem of increase of efficiency of use of control units is considered by the active power of synchronous generators of diesel power plants. As a solution the new innovative offer in the form of the developed device of the measuring converter of active current which is one of the main components of game-trolno-measuring equipment of diesel power plants is offered. The developed scheme is simpler, in comparison with the similar converters of active current executed on the basis of current transformers. In the developed scheme of the measuring converter it is offered to use the differentiating induction converters of current as primary measuring converters. It allows to reduce many times number of the elements entering the standard scheme, and also mass-dimensional characteristics of the device

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2

Inozemtsev, Maxim, Natalia Grigoreva, Natalia Volynkina, and Atabek Alibaev. "Selection and experimental study of the linear displacement converter for the automated monitoring system of mine roofs." E3S Web of Conferences 315 (2021): 03006. http://dx.doi.org/10.1051/e3sconf/202131503006.

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The justification of the linear displacement sensors installation in mine workings is described in this paper. The required technical characteristics of the sensors are given. The main types of primary linear displacement converters are presented. The choice of inductive solenoid-type converters and sensors based on linear differential transformers (LVDT) is justified. The advantages and disadvantages of inductive transducers, their accuracy and measurement limits are described, and measuring methods of inductance of the solenoid-type transducers and the converter output signal based on LVDT are considered. The results of sensors experimental studies based on the solenoid-type inductive transducers are presented.

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3

Manuliak, I. Z., S. I. Melnychuk, Yu Yo Striletskyi, and V. M. Harasymiv. "Gas flow measuring system using signal processing on the basis of entropy estimations." Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, no. 5 (2020): 125–30. http://dx.doi.org/10.33271/nvngu/2021-5/125.

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Purpose. To increase the accuracy of gas flow measurement in tachometric transducers based on the improvement of structural, hardware and algorithmic support of information and measuring systems. Methodology. The gas consumption value is determined by the parameters of information and measurement signals. Sensor signals interacting with the environment are traditionally processed on the basis of amplitude and frequency methods. The research methodology is based on the information theory, methods of statistical and spectral analysis, digital signal processing, the theory of gas dynamics, based on mathematical modeling in a computational experiment, as well as the theory of errors and measurement results uncertainty. The statistical characteristics of the measuring signals of the converter presented in the unitary basis are studied. Findings. The conducted research resulted in development of an information-measuring system to control the sensitivity threshold of the transducers of the primary volume and the volume of gas consumption based on the developed primary transducer, which allows providing relative standard uncertainty of cost determination within 0.5%. A special processor has been developed to calculate the entropy estimates of signal information. Originality. For the first time, a method for the formation and processing of information-measuring signals, which is based on the use of pressure pulsations due to the movement of the measuring element of the converter in the toroidal measuring cell, is proposed. Implementation of the measuring element of a spherical converter, whose density is almost commensurable with the density of the controlled medium is offered. Practical value. The proposed method allows providing a lower sensitivity threshold compared to the industrial implementation of tachometric type transducers.

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4

Sedalishchev, V. N., Ya S. Sergeeva, D. O. Strahatov, and S. P. Pronin. "Specifics of Construction of Measuring Transducers with Logometric Output Based on Interconnected Piezoresonators." Izvestiya of Altai State University, no. 4(120) (September 10, 2021): 53–58. http://dx.doi.org/10.14258/izvasu(2021)4-08.

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The paper presents the results of simulation modeling of measuring devices. The simulation modeling is based on the use of coupled oscillations in systems with two degrees of freedom. Methods of controlling the parameters of the oscillatory system of the converter based on interconnected piezoresonators are considered. A comparative assessment of the metrological characteristics of possible variants of piezoresoanase sensors with logometric (differential) output is conducted. It is shown that when the Q-factor of the oscillatory system of the primary converter is affected, a higher sensitivity of the measuring process is provided by the control of the active resistance of the coupling element replacement circuit between the resonators. In this case, it is proposed to use the ratio of the oscillation amplitudes of one of the interconnected resonators measured at the frequencies of common-mode and antiphase oscillations in the system as the output signal of the sensor. When the frequency-setting parameters of the converter are affected, it is recommended to use the ratio of the oscillation amplitudes of two interconnected piezoresonators measured at one of the normal frequencies of synchronized oscillations in the system to generate the output signal. There are several advantages of measuring devices of this type, such as high sensitivity, simplicity of design, low cost, manufacturability, and operational applicability for harsh conditions.

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5

Gornostaev, A. I. "Optimization of the structure of the unified multichannel interface temperature control module for measuring instruments of spacecraft." Spacecrafts & Technologies 3, no. 3 (2019): 171–83. http://dx.doi.org/10.26732/2618-7957-2019-3-171-183.

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In the development of a unified multi-channel interface temperature control module for measuring instruments, built on a main-modular principle on the basis of the central instrument module and used on spacecraft for various purposes, the primary task is to determine its structure, which allows to provide temperature control on the elements of the spacecraft design in different measurement ranges and with different requirements for accuracy and stability of measurement. The article is devoted to the analysis of general requirements to the structure of the multi-channel interface temperature control module, in which the measuring channels can have different technical characteristics and the choice of variants for measuring the resistance of thermal converters to ensure the elimination of the systematic component of the measurement error. It is shown that in the structure of a unified multichannel interface temperature control module there should be a multichannel measurement scheme forming several measurement channels with different technical characteristics operating on a common channel of analog-to-digital conversion. To match the measuring channels with different input resistances and operating in different measurement ranges with the common channel of the analog-to-digital converter, it is necessary to use a controlled normalizing amplifier. To eliminate the systematic component of the measurement error, it is necessary to use three- or four-wire variants of the measurement schemes of thermal resistance converters, which allow the automatic compensation of the measurement error introduced by the resistances of the wires of the communication lines of the measuring cables, and the automatic calibration of the measurement error introduced by the measuring channels. To compensate for the nonlinear component of the measurement error introduced by thermal resistance converters, it is necessary on the basis of piecewise linear approximation of their nominal static characteristics to divide the operating ranges of measurement into subranges and to carry out automatic calibration measurement errors in each subrange separately.

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6

Dreyzin, V. E., Mohammed Al Kadhimi Ali Noori, and V. E. Bondyrev. "Ionosphere monitoring sensor, placed on nanosatellites." Monitoring systems of environment, no. 2 (June 24, 2021): 54–65. http://dx.doi.org/10.33075/2220-5861-2021-2-54-65.

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In this paper, we propose a sensor for the density and composition of the upper atmosphere (ionosphere), designed for installation on nanosatellites. The relevance and existing problems of direct instrumental studies of the ionosphere at altitudes of 150-500 km are shown. Of the existing types of vacuum meters, the most suitable for autonomous operation at these altitudes are ionization vacuum meters with inverse magnetron primary converters with a cold cathode. However, the existing industrial types of such vacuum meters are unsuitable for operation in the ionosphere due to high concentration of charged particles in the air, resulting in large distortions of the readings. In addition, they have large weight and size characteristics and energy consumption, which exclude the possibility of their installation on nanosatellites. To solve these problems, a mathematical model of the electrophysical processes, occurring in the core of such a converter, was developed which significantly reduced its weight and size characteristics and energy consumption. And to eliminate the influence of charged particles, it is equipped with an electron-ion trap, which additionally made it possible to measure the concentration of electrons and ions in the environment. The design of such a combined converter is described, and calculations of the electric and magnetic fields in the core of the vacuum gauge converter and the electric fields in the interelectrode space of the trap are performed. A method for calculating the current values of such a combined converter has been developed, which makes it possible to estimate the required measurement ranges of the sensor measuring channels. The results obtained allow us to proceed with its experimental design.

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7

Isaiev, V. V., and О. М. Velychko. "RESEARCH OF THE STATE PRIMARY STANDARD OF UNIT OF ALTERNATING CURRENT." Key title Zbìrnik naukovih pracʹ Odesʹkoï deržavnoï akademìï tehnìčnogo regulûvannâ ta âkostì -, no. 2(17) (2020): 14–22. http://dx.doi.org/10.32684/2412-5288-2020-2-17-14-22.

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The article is devoted to the results of the research in order to solve the problem of metrological support of production and operation of thermoelectric power converters, precision meters and AC power sources in the branches of the national economy. The optimal solution to the problem of metrological support is to create a national standard unit of alternating current. The article conducts theoretical research, comparison with foreign analogues and analysis of methods for measuring and reproducing the strength of alternating current. The analysis of the precision means intended for measurement, reproduction and comparison of force and voltage of alternating current is carried out. Theoretical bases of creation of a high-precision standard of unit of alternating current are outlined. To build a national standard, the method of comparing the AC current with the equivalent DC current using a precision thermoelectric converter and shunts was chosen. The composition and requirements to the operating conditions of the national standard are determined. Since the storage and reproduction of a unit of alternating current must be realized by comparison with the equivalent direct current, the main source of uncertainty of measurements of this unit is a combination of uncertainties of measurements of thermoelectric comparator Fluke 792A, precision shunts A40, which are part of the standard, output voltage meters measure the electrical resistance to direct current and the output signal of the thermocomparator. According to the results of research work, for the first time in Ukraine the national standard of an alternating current unit was put into operation.

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8

Крыгин, Сергей Сергеевич, та Юрий Иванович Торба. "Измерение напряженно-деформированного состояния деталей АГТД методом тензометрии". Aerospace technic and technology, № 4sup2 (27 серпня 2021): 44–51. http://dx.doi.org/10.32620/aktt.2021.4sup2.06.

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The subject of study in the article is various methods of measuring the stress-strain state of AGTE parts by the tensometry method. Differences were revealed when measuring the stress-strain state of rotor and stator parts, in different frequency ranges (study of static, static-dynamic and dynamic deformations). Methods for compensating or reducing the influence of external factors on the measurement results, such as temperature changes and electromagnetic interference, are indicated. The aim is to develop recommendations for research of AGTE parts in a test bench in a gradient of varying temperatures and in a complex electromagnetic environment of the engine. A review of the sources of inaccuracies, errors and interference arising during preparation for testing and directly during the measurement of the SDS of AGTE parts is performed. The effects of wiring, cabling, grounding and shielding can not only increase the level of errors, but can also negate the advantages of an expensive and extremely reliable electronic part of the system. The advantages and disadvantages of the most common schemes for connecting strain gages, as well as their areas of application are presented. Possible ways to compensate for imaginary deformations at temperatures outside the range of thermal compensation of primary converters. A list of common strain gauge systems with their advantages and disadvantages is given for each type of parts and frequency ranges of measurements. When strain measurement rotary parts to output the signal from the strain gauge to recording equipment used various current collector. The possibility of using wireless interfaces for communication between the primary converter and the recording equipment is also indicated. The described methods are: ways to compensate for imaginary deformations caused by changes in the temperature of the investigated part and connecting wires. Elimination or minimization of electromagnetic interference on the measuring channel. An estimate is given of the total error in measuring the deformation for a particular object under study for the final loading cycle, the specificity of the bench strain gauge path, the errors of the current collector in bench conditions, and others in the process of static strain gauging.

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9

Pyrozhenko, Ye V., V. V. Sebko, V. G. Zdorenko, N. M. Zashchepkina, and O. M. Markina. "Informative testing method of beer sewage samples for mini-breweries." Archives of Materials Science and Engineering 1, no. 106 (November 1, 2020): 28–41. http://dx.doi.org/10.5604/01.3001.0014.5930.

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Purpose: of the article is to investigate the theoretical rules of thermal transformer eddy current converter (TTC) during the preparation of ecological monitoring of brewery sewage samples based on the implementation of contactless two-parameter eddy current method of testing of the specific electrical conductivity λt and the temperature t of the beer sewage sample. It should be noted that this makes it possible to simultaneously prevent the causes of beer sewage samples deviation from the specified environmental safety indicators and to take adjustments. Design/methodology/approach: The theory of TTC operation concerning the electrical and temperature characteristics testing of beer sewage samples has been further developed by implement new universal transformation functions Δφt = f (Gt) and Δφ = f (xt), which relate the normalized difference components of the converter signals to physical and chemical characteristics of the sample. Due to this, it is possible to simultaneously prevent the causes of beer sewage samples deviation from the specified ecological safety indicators and to take appropriate adjustments. Findings: The method of two-parameter measuring test of the specific electrical conductivity λt and the temperature t of the beer sewage sample was developed on the basis of new universal transformation functions. Analysing the numerical data of electrical conductivity λ, TDS and pH at the initial temperature t1 = 15°C, the alkaline nature of beer sewage was determined. Research limitations/implications: The frequency range of the magnetic field f = 80-100 MHz, it is difficult to maintain in laboratory conditions, so the proposed method requires the use of modern high-frequency equipment, the radius of the probe depends on the radius of the primary converter frame. And therefore is quite a complicate to find appropriate tank. Practical implications: is to determine the nature of beer sewage based on the results of electrical and temperature parameters measurements during implementing a two-parameter eddy current method, which allows to prevent the reasons for beer sewage samples deviations from the specified environmental safety measures and to take appropriate adjustments. An important practical result is also the determination of the signal components and the normalized characteristics of the primary eddy current converter with a sample of beer sewage. They allow to calculate, design and create multi-parameter automated devices for measuring test of the physicochemical parameters of beer sewage samples. In turn, as a result of the physicochemical composition analysis of the sample, improving the accuracy of measurements of physicochemical parameters - there is an opportunity to improve and create advanced methods of wastewater purification on a weak electrolytic basis. Originality/value: The article originality is the investigation of the theoretical rules of thermal TTC by implementing a new multi-parameter eddy current method of measuring the specific electrical conductivity λt and the temperature t of the beer sewage sample based on the implementation of universal transformation functions Δφt = f (Gt) and Δφ = f (xt) that relate the converter signals to the physicochemical characteristics of the beer sewage sample, which helps to prevent the causes of the beer sewage samples deviation from the specified environmental safety indicators and take appropriate adjustments.

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10

Tang, Ge Shi, Li Li, Liang Zeng, Lue Chen, and Lv Zhou. "Measurement and Analysis of the Circuit Delay of CEI System." Applied Mechanics and Materials 128-129 (October 2011): 611–15. http://dx.doi.org/10.4028/www.scientific.net/amm.128-129.611.

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By using a four port Vector Network Analyzer (VNA), a caesium clock, a time-interval counter and a signal source to measure the delay of CEI system segmentally. Design measuring methods respectively for three segments of the circuit. When measure the delay, it is found that, delay of antenna’s amplifier output port to the input port of down converter (DC) is stable; the fluctuation of DC’s delay is less than 2ns; the cable delay’s standard deviation is stable at 0.1ns; we get a nanosecond accuracy for whole system. The methods of time delay measurement and the design of CEI system will provide a foundation and primary data for future deep space missions.

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11

Savchenko, E. G., and V. M. Stuchebnikov. "PRESSURE SENSORS FOR CRYOGENIC MEDIA." Electronic engineering Series 2 Semiconductor devices 259, no. 4 (2020): 43–48. http://dx.doi.org/10.36845/2073-8250-2020-259-4-43-48.

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This article describes theperformance of pressure sensors for ciyogenic media, produced by the industrial group MID A. The company claims that these sensors are superior to any similar devices made in Russia. One of the features is that its primary converter can be installed directly on a tank or pipeline with a cryogenic medium. This is enabled by the use of Silicon-on-Sapphire measuring element. The sensor is capable to measurepressure and temperature simultaneously, using the same sensing element. We demonstrate that the sensor has good metrological characteristics at liquid nitrogen temperatures, and show how the process of thermal cycling in the calibration and manu facturing of the device influences the stabilization of its output signal.

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Osadchuk, O. V., A. O. Semenov, O. S. Zviahin, O. O. Semenova, and A. V. Rudyk. "Increasing the sensitivity of measurement of a moisture content in crude oil." Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, no. 5 (2020): 49–53. http://dx.doi.org/10.33271/nvngu/2021-5/049.

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Purpose. Investigation of a moisture frequency transducer based on a moisture-sensitive capacitive element of a cylindrical structure with mesh electrodes for a system for measuring the amount and parameters of crude oil. Methodology. When constructing a moisture-sensitive element, an oscillatory method for measuring humidity was applied to achieve high sensitivity and accuracy while maintaining a low cost of the device. A moisture sensitive capacitive sensor based on a cylindrical structure with mesh electrodes was introduced into the measuring generator system based on a transistor structure with a negative differential resistance. Findings. Analytical expressions are obtained to describe the dielectric constant of an inhomogeneous mixture of water and oil. Using these equations, the capacitance of a moisture-sensitive sensor with mesh electrodes is calculated as a dependence of the moisture content of crude oil. It was determined that the capacitance of the moisture sensitive sensor increased from 20 to 44 pF when the mass moisture of crude oil changed from 0 to 30%. The sensitivity of the developed capacitive sensor is 0.8 pF/% when using a measuring device in the form of a crude oil pipeline with a diameter of 50 millimeters. Originality. A mathematical model has been developed for the primary transducer of the moisture content of crude oil based on a cylindrical capacitor structure with net-like electrodes, which allows determining the value of the capacitance of the primary transducer of the moisture content of crude oil. A self-oscillator device for controlling the moisture content of crude oil has been developed on the basis of the structure of bipolar and field-effect transistors with a cylindrical capacitor structure with mesh electrodes. Practical value. Circuitry solutions for a moisture transducer for crude oil have been developed. The results of experimental studies showed that for the selected version of the moisture converter circuit, the output signal frequency decreased in the range from 1.617 to 1.27 MHz with a change in the mass moisture content of the Turkmen mixture from 0 to 30%, respectively, and is close to a linear dependence. The wide frequency range of the output signal of the secondary converter with the frequency output of the measured information increases the accuracy of moisture measurement in crude oil by an order of magnitude.

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13

Neftisov, A., O. Talipov, and O. Andreeva. "DEVICE FOR DETERMINING THE VALUE OF THE STEADY-STATE ELECTRICITY IN THE PRIMARY CIRCUIT USING A REED SWITCH AND A MICROPROCESSOR." Scientific Journal of Astana IT University, no. 6 (June 30, 2021): 52–58. http://dx.doi.org/10.37943/aitu.2021.75.95.005.

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This article discusses an innovative device designed to determine the value of the steady-state current in the primary circuit of electrical installations using reed switches and a microprocessor without the use of current transformers. The typical structure of relay protection devices is considered. The main elements are presented. When choosing a primary converter, a reed switch was taken, because it has certain advantages over current transformers. As part of the research, experimental installations for measurements were assembled. They made it possible to emulate the real conditions in which the relay protection devices have to function, unnecessary and to depict the characteristics of future devices. The code is presented that allows the microprocessor device to function according to the laid down algorithm. A device on a reed switch and a microprocessor is presented, which allows transmitting a certain amount of current in the primary circuit in digital form (binary code) to the microprocessor protection. The presented measuring device made it possible to implement a method for determining the magnitude of the steady-state short-circuit current.

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14

Zaitsev, I. O., A. S. Levytskyi, and V. E. Sydorchuk. "AIR GAP CONTROL SYSTEM FOR HYDROGENERATORS." Devices and Methods of Measurements 8, no. 2 (June 9, 2017): 122–30. http://dx.doi.org/10.21122/2220-9506-2017-8-2-122-130.

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In this paper, we report of the solving the actual problem of control the air gap in the hydrogenerators. The aim of the study was development of a computerized information-measuring system for measuring the air gap in the hydrogenator, which used two capacitive sensors with parallel coplanar electrodes, and the method of determining the shape of the envelope parameters hydrogenerator rotor poles relative to the center axis of rotation, using the measurement results of the air gap.In practical studies of the sensor circuit it has been shown that its use allows for the informative value of the sensor capacitance conversion function to obtain a high accuracy and resolution measurement with digital linearization of converting function of the sensor with use program utility. To determine the form deviations of the envelope line of the rotor pole from the ideal cylinder, which is one of the main structural defects of the technological errors as results the distortion of the shape of the air gap in the hydrogenator, when the machine was manufacture and assembly. It is proposed to describe the shape of the envelope to use a Fourier transform. Calculation of the coefficients of the Fourier series is performed using the method of least squares as the regression coefficients.Application of this method in processing the measuring data in a computerized information-measuring system the developed with the primary converter with coplanar parallel electrodes allowed attaining the high measurement accuracy and resolution informative in magnitude of the capacity.

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Roenko, V. V., T. I. Chistyakov, D. V. Tarakanov, and R. V. Khalikov. "Assessment of the electrical conductivity of thermally activated water jets containing injections of inhibiting salt used to extinguish electrical equipment at gas compressor stations." Pozharovzryvobezopasnost/Fire and Explosion Safety 30, no. 1 (March 2, 2021): 64–74. http://dx.doi.org/10.22227/pvb.2021.30.01.64-74.

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Introduction. One of the main problems of fire extinguishing at gas compressor stations is fires in confined spaces where electrical installations can be under voltage. To extinguish these fires, the co-authors propose to use jets of thermally activated water containing salts that inhibit burning. It is necessary to assess the electrical conductivity of water jets to prevent the exposure of fire-fighting units to electrical injuries.Materials and methods. In the experimental study, the principal electricity measuring instrument is digital dc megaohmmeter M4122U, which takes readings if operated from a laptop. The flow rate was measured using IT 2518 measurement complex and TDR14–2–3 primary flow converter of the turbine type. Termit T-35 hardness converter performed electromagnetic water treatment.Theoretical fundamentals. Measurements of leakage currents in jets of thermally activated water, fed through fire nozzles mounted onto a multi-purpose fire truck, were taken, and the maximum permissible distance to an electrical installation was determined experimentally and analytically using an experimental stand.Results and discussions. Averaged values of resistance of a jet of thermally activated water fed from a long-range nozzle at control points do not leave the confidence corridor with a probability of 0.95, which means that they do not cause a significant change in dc resistance. Inhibiting salt, injected into the water, reduces the resistance of jets of thermally activated water by no more than 2–3 % compared to under-heated water. The treatment of the inhibiting salt, injected into the under-heated water, using Termit T-35 hardness converter, does not significantly change the resistance of thermally activated water jets.Conclusions. It is theoretically and experimentally proved that the injection of inhibiting salts into the underheated water, as well as the electromagnetic treatment of water using low-power stiffness converters, do not significantly affect the electrical conductivity of jets of thermally activated water if compared to jets that contain no inhibiting admixtures. The extinguishing of surfaces of electrical installations using jets of thermally activated water containing flame inhibiting injections of salts, as well as the development of an inerting concentration in confined spaces of gas compressor stations is electrically safe for any person engaged in fire extinguishing.

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Cutler, J., J. Bortnik, C. Dunson, J. Doering, and T. Bleier. "CalMagNet – an array of search coil magnetometers monitoring ultra low frequency activity in California." Natural Hazards and Earth System Sciences 8, no. 2 (April 15, 2008): 359–68. http://dx.doi.org/10.5194/nhess-8-359-2008.

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Abstract. The California Magnetometer Network (CalMagNet) consists of sixty-eight triaxial search-coil magnetometer systems measuring Ultra Low Frequency (ULF), 0.001–16 Hz, magnetic field fluctuations in California. CalMagNet provides data for comprehensive multi-point measurements of specific events in the Pc 1–Pc 5 range at mid-latitudes as well as a systematic, long-term study of ULF signals in active fault regions in California. Typical events include geomagnetic micropulsations and spectral resonant structures associated with the ionospheric Alfvén resonator. This paper provides a technical overview of the CalMagNet sensors and data processing systems. The network is composed of ten reference stations and fifty-eight local monitoring stations. The primary instruments at each site are three orthogonal induction coil magnetometers. A geophone monitors local site vibration. The systems are designed for future sensor expansion and include resources for monitoring four additional channels. Data is currently sampled at 32 samples per second with a 24-bit converter and time tagged with a GPS-based timing system. Several examples of representative magnetic fluctuations and signals as measured by the array are given.

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Prathaban, Arumbu Venkadasamy, and Dhandapani Karthikeyan. "Grey wolf optimization-recurrent neural network based maximum power point tracking for photovoltaic application." Indonesian Journal of Electrical Engineering and Computer Science 26, no. 2 (May 1, 2022): 629. http://dx.doi.org/10.11591/ijeecs.v26.i2.pp629-638.

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To increase the photovoltaic (PV) power-generation conversion, MPPT is the primary concern. This works explains about the grey wolf optimization (GWO - RNN)-based hybrid maximum power point tracking (MPPT) method to get quick and maximum photovoltaic (PV) power with zero oscillation tracking. The GWO – RNN based MPPT method doesn’t need additional sensor for measuring irradiance and temperature variables. The NLT is used for the multi-level inverter (MLI) control strategy to achieve less harmonics distraction and less switching losses with better voltage and current profile. This employed methodology brings remarkable aspects in the PV boosting potential extraction. A GWO – RNN controlled LUO converter is a zero output harmonic agreement impedance matching interface that is MPPT is performed by placing the PV modules between the load regulator power circuit and the load regulator power circuit. To actualize the proposed hybrid GWO – RNN model for the PV system, perturb and observe, RNN, ant colony optimization, and artificial bee colony MPPT techniques are employed. The MATLAB interfaced dSPACE interface is used to finish the hands-on validation of the intended grid-integrated PV system. The obtained results eloquently support the appropriate design of higher-performance control algorithms.

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18

Borisov, R. A., I. V. Antonets, and A. V. Krotov. "Static and Total Pressure Sensor Development Methodology based on Elastic Sensing Elements and Optical Rules." Herald of the Bauman Moscow State Technical University. Series Instrument Engineering, no. 1 (134) (March 2021): 33–50. http://dx.doi.org/10.18698/0236-3933-2021-1-33-50.

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Information on the parameters of static atmospheric pressure and total pressure of the incoming air flow is the primary information in the air signal system, which is part of the integrated aircraft control system. This information makes it possible to calculate the altitude and speed of the aircraft for automated and automatic control. Static and total pressures are measured by aerometric parameter sensors, whose technical characteristics largely determine the range and values of the measurement accuracy of the air signal system. Relying on the requirements for aircraft flight safety and in accordance with the existing standards for horizontal and vertical separation, rather stringent requirements are imposed on the accuracy of air pressure measurement. Instrumental errors in measuring static and total air flow pressures with a probability of 0.95 should not exceed 0.02 and 0.05 % of the measurement range. The considered original aerometric pressure sensor based on an optical rule, whose high sensitivity requires minimal deformation of the elastic sensitive element, makes it possible to fulfill these requirements. The non-contact digital information retrieval and the operation of the information system under vacuum conditions significantly increased the efficiency of measurement processes. The paper focuses on an algorithm for calculating the main design parameters of elastic sensitive elements in almost the entire range of their standard sizes taking into account the technical capabilities of the secondary converter. The results of the experiments and experimental studies confirmed the sufficiency of theoretical methods for calculating the parameters of elastic elements for pressure sensors

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Ornatskyi, D. P., S. V. Ehorov, and V. V. Dovhan. "CORRECTION OF ERRORS OF THE MEASURING CHANNEL AVERAGE ACTIVE POWER." Tekhnichna Elektrodynamika 2022, no. 1 (January 24, 2022): 75–81. http://dx.doi.org/10.15407/techned2022.01.075.

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In the article is offered the structural scheme of error correction of the precision measuring channel of average active power for researches in laboratory conditions and exclusively within the limits of changes of the basic frequency of a network. A feature of the scheme is the use of calibration of functional transducers with piecewise linear approximation. The input voltages of these converters are a triangular voltage, which is formed at the output of the integrator by integrating rectangular bipolar meanders, which are formed from the output signals of the frequency divider phase shifter synchronized with the network by a device based on the original precision amplitude-pulse system of phase frequency tuning. Compensatory small-sized low-voltage transformers using measuring amplifiers with differentially split inputs are used as primary converters, which increases the linearity of the characteristic in a wide dynamic range, due to which additive-multiplicative correction of errors of the whole measuring path by two points is realized. The article presents the results of computer modeling of the main functional components of the measuring channel, which confirm its precision and high metrological characteristics. References 10, Figures 2.

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Kirovskaya, I. A., E. N. Kopylova, E. V. Mironova, A. O. Ekkert, R. V. Ekkert, O. V. Kropotin, V. I. Krasheninin, and Yu I. Matyash. "New materials — primary converters of semiconductor measuring cells based on InAs-CdTe system." Omsk Scientific Bulletin, no. 171 (2020): 74–79. http://dx.doi.org/10.25206/1813-8225-2020-171-74-79.

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Banzak, O. V., O. V. Sieliykov, M. V. Olenev, S. V. Dobrovolskaya, and O. I. Konovalenko. "RESEARCH PROCESSES OF GAMMA RADIATION DETECTOR FOR DEVELOPING A PORTABLE DIGITAL SPECTROMETER." Collection of scientific works of the Military Institute of Kyiv National Taras Shevchenko University, no. 69 (2020): 5–12. http://dx.doi.org/10.17721/2519-481x/2020/69-01.

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When considering methods of combating the illicit circulation of nuclear materials, it is necessary to detect trace amounts of materials, and in many cases not to seize them immediately, but to establish the place of storage, processing, routes of movement, etc. As a result, there is a new demand for isotope identification measurements to meet a wide range of different requirements. Measurements should be carried out in the field in a short time, when results need to be obtained within tens of seconds. The devices with which the personnel work should be small and low-background. Such requirements appear when working to identify cases of illegal trade in nuclear materials and radioactive sources, as well as when solving radiation protection problems and when handling radioactive devices and waste. In this work, new generation radiation sensors and measuring systems based on them have been created, which open up previously unknown possibilities in solving problems of nuclear fuel analysis, increasing the accuracy and efficiency of monitoring technological parameters and the state of protective barriers in nuclear power plants, and creating means for IAEA inspections. For the first time a portable digital gamma-ray spectrometer for radiation reconnaissance in the field was developed and created. Distinctive features of such devices are: The analysis showed that the required value of error due to energy dependence of the sensitivity can be achieved using, for example, Analog Devices 10-bit AD9411 ADCs with a sampling rate of 170 MHz. The number of quantization levels is determined by the requirement to measure the dose rate of gamma radiation with an energy of at least 10 keV. This minimum energy corresponds to the use of 10-bit ADCs. On the basis of the developed model, an ionizing radiation detector for dosimetry was created. Its fundamental difference from known devices is the use of CdZnTe crystals as a primary gamma-ray converter (sensor). The advantages of such a solution, proved by previous studies, made it possible to create a detector with: high resolution, no more than 40 keV; a wider dynamic range of values of the recorded radiation dose rate - from background to emergency operating modes of the reactor; lower value of the energy equivalent of noise.

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Danilin, A. I., and A. A. Gretskov. "Primary converters for the implementation of Doppler method for measuring blade oscillation power unit." VESTNIK of the Samara State Aerospace University, no. 2(44) (October 24, 2014): 25. http://dx.doi.org/10.18287/1998-6629-2014-0-2(44)-25-29.

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Zheleznyak, V. K., V. B. Tolubko, L. P. Kriuchkova, and A. P. Provozin. "Rationale for the parameters of the measuring transducer in RFID technology with inductive coupling." Proceedings of the National Academy of Sciences of Belarus, Physical-Technical Series 64, no. 1 (March 28, 2019): 98–109. http://dx.doi.org/10.29235/1561-8358-2019-64-1-98-109.

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In the work the technology of radio-frequency identification of objects with inductive coupling is considered, using passive electric oscillating circuits tuned to fixed frequencies from the working frequency range as identification features of the object. The choice of the primary measuring transducer and the informative parameter is based on the results of the analysis of the system of inductively coupled active and passive electric oscillation circuits, known from the theory of radio engineering circuits. The parameters of the measuring transducer ensuring the fulfillment of the requirements for identification and localization of objects specified by technological conditions are substantiated. Factors that are potentially dangerous with respect to reducing the information reliability of the measuring transducer are considered, as well as the possibility of reducing their influence to a minimum. The problems of experimental research are formulated. It is shown that the analysis can be performed by software discrete adjustment of the primary measuring transducer and the generator feeding it. In this case, the task of increasing the speed is targeted at decreasing the duration of the step of tuning the primary measuring transducer. The required reliability of object identification is achieved by: ensuring high stability of the frequencies of the generator supplying the primary measuring transducer; accuracy and stability of tuning of the primary measuring transducer to the frequencies of the supplying generator; protection of the primary measuring transducer from the influence of interference generated by external sources and other measuring converters of the object identification system (electromagnetic compatibility of the object identification system); sufficient magnitude of the response of the primary measuring transducer to the introduction of passive electrical oscillation circuits; sufficient frequency tuning interval for passive electric oscillation circuits; accuracy and stability of tuning of passive electric oscillation circuits; stability of the detection threshold relative to the initial level of the informative parameter. Electromagnetic compatibility of measuring transducers, whose sensing elements are in the zone of mutual influence, is provided by synchronizing the operation of measuring transducers with shunting of inactive sensors, screening, mutual orientation and spacing of sensing elements.

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Likhttsinder, Boris Ya. "Ensor networks – distributed information measuring and information control systems." Vestnik of Samara State Technical University. Technical Sciences Series 29, no. 2 (August 30, 2021): 76–87. http://dx.doi.org/10.14498/tech.2021.2.5.

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The problems of control and management of geographically distributed objects are considered. The sensor networks operating on the ZigBee technology are considered. The characteristics of the 802.15.4 ZigBee standard are given. The advantages of this technology are shown when building networks that are not very critical to traffic delays. The elements of such a network are considered. The primary converters used in such networks and their energy characteristics are considered. The issues of reducing and compensating delays in control circuits are considered. It is shown that modern wireless sensor networks can be considered as distributed information measuring and information control systems.

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Moskalyuk, S. A., and E. B. Yankevich. "The use of precision optical Fresnel dividers together with primary standard laser radiation intensity measuring converters." Measurement Techniques 55, no. 3 (June 2012): 265–74. http://dx.doi.org/10.1007/s11018-012-9950-x.

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Yakubov, Mirjalil, Kamolbek Turdibekov, Absaid Sulliev, Islom Karimov, Saydiaziz Saydivaliyev, and Sarvar Xalikov. "Improvement of the information-measuring complex for diagnostics of traction power supply objects at high-speed traffic." E3S Web of Conferences 304 (2021): 02014. http://dx.doi.org/10.1051/e3sconf/202130402014.

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This paper considers the improvement of the information-measuring complex for diagnostics and monitoring of traction power supply equipment under high-speed traffic, which has several features associated with a multilevel hierarchical structure, spatial distribution of objects, energy modes and functional relationships. The analysis of the transmission and conversion of measuring analogue information into a digital one, considering the maximum frequency of the primary signal spectrum components according to the sampling and quantization parameters to determine the time of the signal converted into a digital form is made. Functional dependencies and an algorithm for measuring information processing, considering the multilevel structure of traction power supply, which allow increasing the reliability and accuracy of diagnosing the main objects in high-speed traffic, are obtained.

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Sattarov, Khurshid. "THE MAIN REQUIREMENTS OF CLOUD COMPUTING MONITORING FOR PRIMARY MEASURING CONVERTERS OF THE POWER SUPPLY SYSTEM WITH SPECIFIC LOADS." Вестник КазАТК 120, no. 1 (March 25, 2022): 106–10. http://dx.doi.org/10.52167/1609-1817-2022-120-1-106-110.

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Large-scale measures are being taken in the republic to further improve the energy sector, the widespread use of renewable energy sources, as well as the creation of elements, devices and a complex for monitoring the quality indicators of reactive power of electricity supply systems. The article discusses the development and requirements of converters of quantities and parameters for Cloud Computing monitoring of power supply with a unified output value in the form of secondary voltage.

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OSADCHUK, Jaroslav, Alexander OSADCHUK, and Vladimir OSADCHUK. "RESEARCH OF AUTOGENERATOR PARAMETRIC TEMPERATURE SENSORS." Herald of Khmelnytskyi National University 305, no. 1 (February 23, 2022): 175–83. http://dx.doi.org/10.31891/2307-5732-2022-305-1-175-183.

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Autogenerator parametric temperature sensors based on transistor microelectronic structures with negative differential resistance with primary transducers such as thermistors and thermodiodes are proposed, and the primary thermosensitive elements are active elements of sensor autogenerator circuits, which simplifies their design. Based on the consideration of physical processes in primary heat-sensitive transducers and autogenerators of sensors, mathematical models of temperature sensors have been developed, on the basis of which parametric dependences of transformation and sensitivity functions are obtained. It is shown that the main contribution to the conversion function is made by temperature. This causes a change in the equivalent capacitance and negative differential resistance of the sensor autogenerators, which in turn changes the output frequency of the temperature sensors. The sensitivity of the temperature sensors varies from 1.2 kHz/0C to 2.35 kHz/0C when the temperature changes from 0 0C to 125 0C. The obtained parametric dependences of temperature sensor conversion functions show the possibility to obtain basic sensor characteristics much easier and clearly demonstrate the influence of each parameter of primary converters and autogenerator elements on sensor output frequency in comparison with calculations of conversion functions from equivalent device circuits based on Kirchhoff equations solution. Frequency output temperature sensors do not require analog-to-digital converters and amplifiers for further processing of information signals, which reduces the cost of information and measuring equipment, in addition, it is possible to transmit information over distances when operating sensors at ultrahigh frequencies.

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Kuchumov, Mikhail, and Sergej Evtushenko. "New Soil Stress Measurement Sensor Based on the Effect of Elastic Charging of Electrodes." Buildings 12, no. 3 (March 9, 2022): 327. http://dx.doi.org/10.3390/buildings12030327.

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The purpose of this work was to develop a prototype of a soil stress sensor using a new technique for converting mechanical quantities, with functions for measuring stress changes in soils emerging under the action of a dynamic load associated with earthworks using construction machinery, impact of transport, underground explosions and earthquakes. The development is intended to solve problems in increasing the overall efficiency of monitoring buildings and structures and measurement accuracy. Within the framework of the study, the basic requirements for primary converters of mechanical quantities operating underground were formulated. The design solutions of such sensors, which affect the quality of the information received, have been evaluated. As a result of the study, a new effect of “elastic charging of the interfacial layer of a solid metal electrode” for measuring normal stress in soils was explored and proposed eligible for this purpose. Consequently it became possible to apply this new approach to developing the soil stress measurement sensor, including the creation of its functional scheme of operation, and selection of the hardware set, construction elements and materials taking into account the nature of sensor work. Eventually, laboratory experiments obtaining numerical characteristics were carried out.

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Курбатов, А. В., Д. А. Кондрашов, И. А. Драничников, and Ф. А. Попов. "INFORMATION MEASURING SYSTEM STRENGTH TESTS. SYNCHRONIZATION SUBSYSTEM OF MEASURING AND EXECUTIVE EQUIPMENT." Южно-Сибирский научный вестник, no. 1(41) (February 28, 2022): 17–22. http://dx.doi.org/10.25699/sssb.2022.41.1.010.

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В промышленности и научных исследованиях существуют быстропротекающие дорогостоящие процессы, которые невозможно будет повторить. Такие процессы, в частности, имеют место при стендовых испытаниях изделий из высокоэнергетических материалов. Как объект измерений они характеризуются несколькими десятками видов измеряемых параметров, значительным количеством измерительных каналов, жесткими требованиями к точности как собственно измерений, так и фиксации времени их проведения. В Информационно-Измерительной Системе (ИИС) прочностных испытаний, разработанной в АО «ФНПЦ «Алтай», решение данной задачи осуществляется средствами рассмотренной в статье подсистемы, реализованной в виде аппаратно-программного комплекса «Центральный пульт». В структуре ИИС он обеспечивает выполнение функций: синхронизация процессов измерений модулей в многоканальной системе сбора данных; мониторинг процессов, протекающих при испытании изделия; управление внутренними системами испытательного стенда по заданным сценариям; сохранение технических данных о процессах, протекающих во время испытания изделия, с их точными временными характеристиками. Во время проведения испытания подсистема обеспечивает синхронизацию процессов запуска и остановки многоканальных систем сбора данных, первичных преобразователей, исполняющих и управляющих систем. Мониторинг процессов, протекающих в изделии и на стенде во время испытания, позволяет отслеживать и фиксировать неисправности испытуемого изделия или стенда. Управление системами испытательного стенда осуществляется по заданным сценариям, позволяющим реализовать временные диаграммы работы аппаратуры - циклограммы. Данные о состоянии процессов, имеющих место при испытании изделий, в т.ч. и их точные временные характеристики, сохраняются в базе данных. В процессе эксплуатации подсистемы в составе ИИС она была применена при испытаниях различных видов изделий с использованием двухсот датчиков потенциометрии, сотни датчиков тензометрии и сотни температурных датчиков, обеспечив высокую точность синхронизации измерительных процессов при научных исследованиях быстропротекающих дорогостоящих процессов. In industry and research, there are high-speed, costly processes that cannot be replicated. Such processes, in particular, take place during bench tests of products made of high-energy materials. As an object of measurements, they are characterized by several dozen types of measured parameters, a significant number of measuring channels, strict requirements for the accuracy of both the actual measurements and the recording of the time of their carrying out. In the Information-Measuring System (IMS) of strength tests, developed at JSC "Federal Scientific and Practical Center" Altai ", the solution of this problem is carried out by means of the subsystem considered in the article, implemented in the form of the hardware-software complex" Central console ". In the structure of the IMS, it provides the following functions: synchronization of the measurement processes of modules in a multichannel data collection system; monitoring of processes occurring during product testing; control of the internal systems of the test bench according to specified scenarios; preservation of technical data on the processes occurring during product testing, with their exact time characteristics. During the test, the subsystem provides synchronization of the processes of starting and stopping multichannel data acquisition systems, primary converters, execution and control systems. Monitoring of the processes occurring in the product and on the bench during testing allows you to track and fix malfunctions of the tested product or bench. The control of the test bench systems is carried out according to the specified scenarios, which make it possible to implement the timing diagrams of the equipment operation - cyclograms. Data on the state of the processes taking place during the testing of products, incl. and their exact timing are stored in the database. During the operation of the subsystem as part of the IMS, it was used in testing various types of products using two hundred potentiometry sensors, hundreds of strain gauges and hundreds of temperature sensors, ensuring high accuracy of synchronization of measuring processes in scientific research of high-speed expensive processes.

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Druzhinin, A. A., A. P. Kutrakov, S. I. Nichkalo, and V. M. Stasiv. "Information and measuring system on the basis of strain sensors based on silicon microcrystals." Технология и конструирование в электронной аппаратуре, no. 3 (2018): 9–14. http://dx.doi.org/10.15222/tkea2018.3.09.

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One of the promising directions of development of information and measuring systems for monitoring and diagnostics is the use of intelligent sensors of various physical quantities, in particular pressure, temperature, deformation, acceleration, etc. The main functional feature that distinguishes such sensors is the possibility of signal processing directly in the measuring zone, which involves the temperature compensation of the output signal, linearization of the transformation function. Along with primary converters, intelligent sensors include analog-to-digital and digital-to-analog converters, microcontroller, memory-storage device, input/output interfaces. However, the technologies used today for the creation of existing microelectronic sensors are quite complex and require special process equipment and materials, that leads to an increase in their value. The aim of this work is to develop an information and measurement system for use in conjunction with mechanical sensors based on strain gauges made of silicon whiskers in terms to provide a higher efficiency. The deformation and temperature characteristics of sensors of mechanical quantities (pressure, force and deformation) with strain gauges on the basis of p-type Si whiskers (ρ=0.005—0.02 Ω∙cm) in the temperature range from –60 to +60°C were analyzed. It has been established that at a deformation level of ±6∙10–4 relative units, the high values of sensitivity and linearity of strain gauge characteristics are maintained, and the hysteresis effect due to the characteristics of elastic elements is shown to the smallest extent. It is shown that the temperature dependence of relative change in the resistance of strain gauge resistors based on p-Si whiskers with resistivity of 0.005 Ω∙cm is characterized by the smallest nonlinearity. This simplifies the problem of compensation of the temperature errors, which are typical for such sensors. The temperature coefficient of resistance for strain gauges was found to be 0.15%/°Ñ. The information and measuring system was developed on the basis of pressure sensor with strain gauges made of silicon whiskers (ρ=0.005 Ω∙cm). This pressure sensor provides the simultaneous measurement of pressure and temperature in the ranges 0...100 kPa and –60...+60°Ñ, respectively. The measuring channel of the developed system was based on the AVR ATmega328P microcontroller, which provides the ability to create modern high-precision distributed data gathering and display systems. As a result of testing, satisfactory results were obtained regarding stability, sensitivity and measurement ranges of the developed information and measuring system. The main measurement error did not exceed 0.1%. The measuring circuit can be easily adapted to a new task without making any significant changes to its hardware, the function of the device is easily adjusted by changing the work program.

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Surekha, S., and Md Zia Ur Rahman. "An Intelligent cognitive sensing and detection strategy for medical telemetry networks." Journal of Intelligent & Fuzzy Systems 41, no. 6 (December 16, 2021): 6127–36. http://dx.doi.org/10.3233/jifs-202673.

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In medical telemetry networks, cognitive radio technology is mostly used to avoid licensed spectrum underutilization and by providing access to unlicensed spectrum users without causing interference to primary users, this concept is widely used in development of smart hospitals and smart cities. In medical telemetry networks frequency spectrum concept is used for providing treatment to patients who are far away from hospitals. In cognitive radios, spectrum sensing concept is used in which energy detection method is mostly used because it is simple to implement. While measuring health care environments using cognitive radios probability detection, false alarm probability and threshold parameters are calculated. In this paper for identifying spectrum holes in spectrum sensing using energy detection, distributed diffusion non-negative least mean square algorithm is proposed. It gives better results compared to energy detection concept alone in terms of probability detection converged earlier. If number of nodes are increasing probability detection is decreased from one and move towards left and its SNR is around 1.5-2 dB with proposed method. Hence simulation results give better results in terms of sensing ability while measuring patient condition.

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Dang, Jie, Ning Wang, and Hasan K. Atiyeh. "Review of Dissolved CO and H2 Measurement Methods for Syngas Fermentation." Sensors 21, no. 6 (March 19, 2021): 2165. http://dx.doi.org/10.3390/s21062165.

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Syngas fermentation is a promising technique to produce biofuels using syngas obtained through gasified biomass and other carbonaceous materials or collected from industrial CO-rich off-gases. The primary components of syngas, carbon monoxide (CO) and hydrogen (H2), are converted to alcohols and other chemicals through an anaerobic fermentation process by acetogenic bacteria. Dissolved CO and H2 concentrations in fermentation media are among the most important parameters for successful and stable operation. However, the difficulties in timely and precise dissolved CO and H2 measurements hinder the industrial-scale commercialization of this technique. The purpose of this article is to provide a comprehensive review of available dissolved CO and H2 measurement methods, focusing on their detection mechanisms, CO and H2 cross interference and operations in syngas fermentation process. This paper further discusses potential novel methods by providing a critical review of gas phase CO and H2 detection methods with regard to their capability to be modified for measuring dissolved CO and H2 in syngas fermentation conditions.

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Nakamura, H., I. Asano, M. Adachi, and J. Senda. "Analysis of pulsating flow measurement of engine exhaust by a Pitot tube flowmeter." International Journal of Engine Research 6, no. 1 (February 1, 2005): 85–93. http://dx.doi.org/10.1243/146808705x7329.

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The Pitot tube flowmetering technique has been used to measure pulsating flow from a vehicle engine exhaust. In general, flowmetering techniques that utilize differential pressure measurements based on Bernoulli's theory are likely to show erroneous readings when measuring an average flowrate of pulsating flow. The primary reason for this is the non-linear relationship between the differential pressure and the flowrate; i.e. the flowrate is proportional to the square root of the differential pressure. Therefore, an average of the differential pressure does not give an average of pulsating flow. In this study, fast response pressure transducers have been used to measure the pulsating pressure. Then the pulsating differential pressure is converted to the flowrate while keeping the pulsation unaveraged. An average flowrate is then calculated in the flowrate domain in order to maintain linearity before and after averaging. The peak amplitude of a pulsation measured here was about 1800 L/min at an average flowrate of 70 L/min when the engine ran at idle speed. This measurement has been confirmed by measuring the pulsation with a gas analyser. The results show a large amount of back and forth gas movement in the exhaust tube. This magnitude of pulsation can cause as much as five times higher erroneous results with the pressure domain averaging when compared to a flowrate domain averaging.

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Kolipinski, Mietek, Mani Subramanian, Kristina Kristen, Steven Borish, and Stacy Ditta. "Sources and Toxicity of Mercury in the San Francisco Bay Area, Spanning California and Beyond." Journal of Environmental and Public Health 2020 (September 15, 2020): 1–17. http://dx.doi.org/10.1155/2020/8184614.

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Анотація:

This report synthesizes and evaluates published scientific literature on the environmental occurrence and biomagnification of mercury with emphasis on the San Francisco Bay Area (SFBA), California. Mercury forms various compounds, well known for their toxicity in humans and environmental ecosystems. Elemental mercury is transported and distributed by air, water, and sediments. Through the metabolic processes of algae and bacteria, mercury is converted into organic compounds, such as methylmercury (MeHg), which then bioaccumulates up through trophic levels. In fish, it is found primarily in skeletal muscle, while in humans, the primary target organs are the brain and kidneys. Health concerns exist regarding bioaccumulation of mercury in humans. This paper reviews the known anthropogenic sources of mercury contamination, including atmospheric deposition through aerial transport from coal burning power plants, cement production, and residual contaminants of mercury from gold mining, as well as mercury-containing waste from silver amalgams emitted from dental offices into waterways. Although tools exist for measuring mercury levels in hair, breast milk, urine, blood, and feces in humans, current diagnostic tools are inadequate in measuring total mercury load, including deposited mercury in tissues. Additionally, insufficient attention is being paid to potential synergistic impacts of mercury interaction with multipliers such as lead, cadmium, and aluminum. We provide specific data on methylmercury concentrations at different trophic levels, followed by recommendations for reducing the level of mercury in the SFBA in order to protect the health of humans and other species.

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Sajith, Vishnu. "Thermal Energy and Power Production: Impact on the Global Environment." International Journal for Research in Applied Science and Engineering Technology 9, no. 11 (November 30, 2021): 286–94. http://dx.doi.org/10.22214/ijraset.2021.38787.

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Abstract: Thermal energy is energy that comes from a substance whose molecules and atoms are vibrating faster due to a rise in temperature. In thermodynamic terms, Thermal energy is the internal energy present in a system in a state of thermodynamic equilibrium by virtue of its temperature. Thermal energy cannot be converted to productive work as easily as the energy of the systems that are not in thermodynamic equilibrium. Matter is made up of molecules and atoms that are constantly moving. The increase in temperature causes these particles to move faster and collide with each other. The hotter the substance, the more its particles move, and the higher its thermal energy. Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy. That is, thermodynamics involves measuring thermal energy. ➣ In this paper we will be talking about the primary concepts of thermodynamics related to the formulation of thermal energy and then explain the correlation between thermal energy and thermal power. We also have included a CASE Study on the adverse Environmental effects of Thermal power production.

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Zhang, Rong, and Andrew G. Alleyne. "Dynamic Emulation Using an Indirect Control Input." Journal of Dynamic Systems, Measurement, and Control 127, no. 1 (June 16, 2004): 114–24. http://dx.doi.org/10.1115/1.1876496.

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This paper presents a generalized framework to analyze and design controllers for a class of dynamic emulation systems. This class of systems features some structurally distinctive control frameworks which inherently limit the available bandwidth for dynamic emulation. The primary focus is on control structures that we define as indirect. This means the signal from the controller does not affect the physical plant directly; it interacts in combination with other exogenous signals to affect a behavior on the physical system interacting with the emulated load. It is shown that the achievable closed-loop performance is limited in a unique way: the high-frequency response of the controlled closed-loop system converges to the dynamics of the open-loop physical plant that is interacting with the emulated load. This paper illustrates the three controller configurations of the indirect emulation and gives guidelines on how to improve the performance within the identified structural limitations. The three configurations are: a feedback design measuring plant output only, a feedforward design measuring an exogenous signal, and a two degree-of-freedom design combining feedback and feedforward measurements. A detailed analysis in the frequency domain is used to support the experimental results illustrated on a Hardware-in-the-Loop (HIL) system. The demonstration case is a high-bandwidth transient dynamometer to emulate rapidly varying loads associated with an earthmoving vehicle powertrain.

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Yablokov, A. A., G. A. Filatova, A. S. Timofeev, and A. E. Petrov. "Development and study of the fault location function for the information system based on digital transformers." Vestnik IGEU, no. 4 (2019): 63–74. http://dx.doi.org/10.17588/2072-2672.2019.4.063-074.

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The existing methods of fault location (FL) on power lines are often unable to provide the required accuracy and are unstable to the influence of metering-distorting factors. The main source of errors of the FL devices is the primary current and voltage transducers. Using innovative current and voltage sensors (including Rogowski coils for physical measurement of the primary current derivative) as part of digital measuring transformers allows significant improvements in the accuracy of measuring electrical values during short-circuits. The aim of the work was to develop an enhanced accuracy FL function as part of an information system (IS) that takes into account the characteristics of non-traditional primary converters and, in general, digital current and voltage transformers. The methods of the electrical circuit theory, mathematical simulation and physical-mathematical modeling are used. The computer experiments are carried out in the modern modeling systems Matlab + Simulink and RSCAD, and the physical and mathematical modeling – in the real-time modeling complex RTDS. For modeling power transmission lines, the specific parameters were assumed to be known and unchanged. The developed FL function differs from its analogs as it uses information signals from digital current and voltage transformers, is characterized by operation stability under the influence of some metering-distorting factors (presence of transient resistance, changes in electrical load, breakdown phase, presence of capacitance of phases to earth, etc.) and an error not exceeding 8 % (at large distances and in the presence of transitional resistance in short-circuit locations) or 3 % (in the absence of metering-distorting factors). A prototype of the IS with the FL function has been designed and experimentally tested. The developed FL function allows increasing the accuracy of short-circuit location determination and reducing the time of finding the fault. Fault location IS data can be used by the operating personnel of electrical networks. The reliability of the obtained results is determined by the methods of the classical electrical circuit theory and the theory of electromagnetic transients in electrical power systems, and by the convergence of the results obtained in the study of the function accuracy in different modeling complexes.

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Artemieva, Olga, Daria A. Nikanova, Alexander Kositsin, Irina Lashneva, Larisa P. Ignatieva, Alexander A. Sermyagin, and Natalia A. Zinovieva. "PSX-B-21 Diagnosis of early mastitis in dairy cows: Somatic cells and bacterial pathogen measuring." Journal of Animal Science 99, Supplement_3 (October 8, 2021): 269–70. http://dx.doi.org/10.1093/jas/skab235.494.

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Abstract Mastitis is an inflammatory condition of the breast that can be caused by chemical, physical, traumatic injury or bacteria. In recent years, biomarkers for the mastitis diagnosis have been actively studied. The aim of the study was to assess the relationship between SCC and pathogenic bacteria in milk occurrence. The study carried out by milk samples collected in the experimental herd (Krasnodar region, Russia) from 85 Holsteinized Black-and-White cows. Healthy cows (HC; n = 4), cows at risk for clinical mastitis (RCM, n = 22), subclinical (SCM; n = 25) and clinical mastitis (CM; n = 34) groups were divided by a bacteriological cultivation and SCC level (Fossomatic7 DC). SCC results were logarithmically converted to SCS. Consequent groups were included animals with SCS level: HC (SCS < 4.1), RCM (4.2≤SCS≤5.3), SCM (5.4≤SCS≤6.3), CM (SCS >6.4). HC group of animals showed SCS equal to 3.11±0.28, 4.85±0.44 for RCM, 5.8±0.28 for SCM and 7.43±0.87 for CM. Identification of isolated bacteria species was carried out by conventional biochemical methods using the API20E, APIStaph, API20Strep tests (bioMerieux SA,France). Number of isolated pathogenic bacteria in CM group was 57 strains of which 33.3% were attributed to Enterobacteriaceae, 45.6% to coagulase-negative staphylococci (CONS), 12.3% to S.aureus and 8.8% to Ps.aeruginosa. In SCM group there were assigned 48 strains: 32.5% to Enterobacteriaceae strains, 42.5% to CONS, 20.0% to S.aureus, 5.0% to Ps.aeruginosa. The antibiotic susceptibility was determined according to NCCLS and EUCAST. S.aureus isolates showed the highest sensitivity to erythromycin (4.3% of resistant strains) and the highest resistance to ciprofloxacin (100%), tetracycline (95.0%), rifampicin (88.5%), benzylpenicillin (79.3%), novobiocin (69.2%) and fusidin (65.5%). The primary analysis of SCC and milk microbiological profile can be able to increase the accuracy of mastitis occurrence diagnosing that contributes to taking the right decision for choosing an antibiotic to preserve the cows’ health in Russian cattle population. The study was funded by RSF (project No.21-76-20046)

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Lin, Huilong, Xuelu Wang, Yingjun Zhang, Tiangang Liang, Qisheng Feng, and Jizhou Ren. "Spatio-temporal dynamics on the distribution, extent, and net primary productivity of potential grassland in response to climate changes in China." Rangeland Journal 35, no. 4 (2013): 409. http://dx.doi.org/10.1071/rj12024.

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Net primary productivity (NPP) of grassland is one of the key components in measuring the carrying capacity of livestock. Not only are grassland researchers concerned with the performance of NPP simulation models under current climate conditions, they also need to understand the behaviour of NPP–climate models under projected climatic changes. One of the goals of this study was to evaluate the three NPP–climate models: the Miami Model, the Schuur Model, and the Classification Indices-based Model. Results indicated that the Classification Indices-based Model was the most effective model at estimating large-scale grassland NPP. Both the Integrated Orderly Classification System of Grassland and the Classification Indices-based Model were then applied to analyse the succession of grassland biomes and to measure the change in total NPP (TNPP) of grassland biomes from the recent past (1950–2000) to a future scenario (2001–2050) in a geographic information system environment. Results of the simulations indicate that, under recent-past climatic conditions, the major biomes of China’s grassland are the tundra and alpine steppe, and steppe, and these would be converted into steppe and semi-desert grassland in the future scenario; the potential grassland TNPP in China was projected to be 0.72 PgC under recent-past climatic conditions, and would be 0.83 Pg C under the future climatic scenario. The ‘safe’ carrying capacity of livestock that best integrates a wide range of factors, such as grassland classes, climatic variability, and animal nutrition, is discussed as unresolved. Further research and development is needed to identify the regional trends for the ‘safe’ carrying capacity of livestock to maintain sustainable resource condition and reduce the risk of resource degradation. This important task remains a challenge for all grassland scientists and practitioners.

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Liu, Sixin, Qi Lu, Hongqing Li, and Yuanxin Wang. "Estimation of Moisture Content in Railway Subgrade by Ground Penetrating Radar." Remote Sensing 12, no. 18 (September 8, 2020): 2912. http://dx.doi.org/10.3390/rs12182912.

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China is strongly dependent on railway transportation, but the frost heaving of the subgrade in cold regions has seriously affected the safety and comfort of trains. Moisture content is an essential parameter in the subgrade frost heave. Non-destructive and efficient geophysical methods have great potential in measuring the moisture content of railway subgrade. In this paper, we use the common mid-point (CMP) measurement of ground penetrating radar (GPR) to estimate the propagation velocity of electromagnetic waves in a subgrade application. We establish a synthetic model to simulate the railway subgrade structure. The synthetic CMP gathers acquired from shallow and thin layers are seriously disturbed by multiple waves and refraction waves, which make the routine velocity analysis unable to provide accurate velocities. Through the analysis of numerical simulation results, it is found that the primary reflection waves, multiple waves, and refraction waves are dominant in different offset ranges of CMP gather. Therefore, we propose a solution of the optimal gather at a certain range of offset dominated by the primary reflection wave to calculate the velocity spectrum and extract the accurate velocities for the subgrade model. The relative dielectric constants of the corresponding layers are calculated after the stacking velocities are converted into the interval velocities. Then, the moisture content is obtained by the Topp formula, which expresses the relationship between dielectric constant and moisture content. Finally, we apply the optimal gather scheme and the above interpretation process to the GPR data acquired at the railway site, and we form a long moisture content profile of the railway subgrade. Compared with the polarizability measured by the induced polarization (IP) method, it is found that the regions with high moisture content correspond to polarizability anomalies with different strengths. The comparison shows the reliability of GPR results to some extent.

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Gutsche, Alexander, Nico Dingenouts, Xiaoai Guo, Manuel Meier, and Hermann Nirschl. "Probing the absolute scattering intensity by means of a laboratory-based small-angle X-ray scattering camera using an imaging plate detector." Journal of Applied Crystallography 49, no. 1 (February 1, 2016): 15–23. http://dx.doi.org/10.1107/s1600576715021469.

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This paper deals with the application of an imaging plate (IP) detector for probing absolute intensities in small-angle X-ray scattering experiments. The IP detector is used with an in-house modified Kratky camera. It is shown that the normalization of scattering data to the transmitted primary beam intensity properly compensates for various unwanted features typically associated with the IP detector,e.g.the fading effect and poorly reproducible scanning times, promoting precise absolute intensity calibration. The absolute intensity calibration was performed by measuring a large number of different silica sols serving as secondary standards. The calibration factor, which converts the measured data into absolute units, was determined by the average over the data obtained for different silica sols, providing a precise calibration of the IP detector. In particular, it is shown that silica sols do not require application of synchrotron radiation or a long exposure time as typically needed if pure liquids or standard proteins are used as secondary standards. To check the applicability of the IP detector in a real synthesis, Stöber silica particles were synthesized under various reaction conditions and the scattering intensity was probed and converted into absolute units. The volume fractions and the number densities of silica particles provided by the absolute intensities showed a good agreement with theoretical values predicted for the different reaction conditions. Therefore, the IP detector can be used for accurate probing of absolute intensities.

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Machelski, Czesław. "Soil–steel structure shell displacement functions based on tensometric measurements." Studia Geotechnica et Mechanica 40, no. 3 (October 20, 2018): 170–79. http://dx.doi.org/10.2478/sgem-2018-0020.

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AbstractThis paper analyses the effects of loads that change their location, i.e. moving but quasi-static loads. Displacements defining the deformation of the soil–steel structure’s shell buried in soil are calculated from the results of measurements performed using a dense grid of points located on the circumferential section of the corrugated plate. In this way, all the components of the structure, namely the corrugated plate, the backfill and the pavement with its foundation, as well as the natural (real) principles of their interaction, are taken into account in the solution. In the proposed algorithm, unit strains are converted into displacements, whereby results as accurate as the ones obtained by direct experimental measurements are obtained. The algorithm’s main advantages are that the number of points is limitless, they are regularly distributed on the circumferential section of the shell and any displacement directions can be obtained. Consequently, the deformations of the shell can be faithfully reproduced. The algorithm’s convenient feature is that one can use a simplified computational diagram of the shell in the form of a beam having the shape of the shell in 2D space (without the other components of the soil–steel structure). The advantage of this measuring method (electric resistance tensometry) is that there is no need to build the solid scaffold used for displacement measurements. The research focuses on the analysis of the displacements and the unit strains arising during the primary and secondary (return) travel of the load.

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Koefoed-Nielsen, Pernille B., Nikolaos Karamperis, and Kaj Anker Jørgensen. "Validation of the Calcineurin Phosphatase Assay." Clinical Chemistry 50, no. 12 (December 1, 2004): 2331–37. http://dx.doi.org/10.1373/clinchem.2004.034066.

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Abstract Background: The calcineurin inhibitors cyclosporine and tacrolimus are used as primary immunosuppressive drugs in transplant patients. Measuring calcineurin phosphatase (CaN) activity is a proposed pharmacodynamic approach to optimize dosing of these drugs. Methods: Whole blood samples were obtained from 10 patients treated with calcineurin inhibitors and 20 healthy volunteers and frozen at −80 °C. CaN activity was measured by its ability to dephosphorylate a 19-amino acid peptide previously phosphorylated with [γ-32P]ATP. Radioactivity was quantified by liquid scintillation, and results were converted from cpm to U of CaN. Validation of the assay included enzyme kinetics, linearity, precision (at low and normal CaN activities), analytical recovery, and limit of detection. Results: The enzyme followed simple Michaelis-Menten-type kinetics: Vmax was estimated as 240 nmol 32P · L−1 · min−1 and Km as 70 μmol/L. The assay was linear within the concentration range examined. Analytical recovery varied from 68% to 72%. The total analytical SD was 0.059 and 0.053 U of CaN for high and low CaN activity, respectively. The within-day SD for high and low activity was 0.032 and 0.039 U of CaN, respectively. The limit of detection was 0.04 U of CaN, which is far below the values measured in patients treated with CaN inhibitors. Conclusions: In addition to the pharmacokinetic monitoring applied today, the CaN assay can be used to monitor patients treated with calcineurin inhibitors, hopefully leading to prolonged graft survival.

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Oort, Q., L. Dirven, F. Boele, R. Grant, H. Sato, A. Talacchi, T. Young, J. C. Reijneveld, and M. J. B. Taphoorn. "OS3.3 Development of an EORTC questionnaire measuring instrumental activities of daily living (IADL) in patients with brain tumours: phase I-III." Neuro-Oncology 21, Supplement_3 (August 2019): iii9. http://dx.doi.org/10.1093/neuonc/noz126.027.

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Abstract BACKGROUND In brain tumour patients, impairments in every day functioning can impact quality of life, and are therefore an important outcome in both clinical trials and practice. One way to measure every day functioning is with an activities of daily living (ADL) questionnaire. Instrumental ADL (IADL) are the cognitively more complex activities, that are essential to function autonomously within society. Cognitive decline may therefore negatively impact IADL, making these activities particularly relevant to brain tumour patients. The aim of this study is to develop a reliable and valid questionnaire to measure IADL in primary malignant and metastatic brain tumour patients. MATERIAL AND METHODS The questionnaire development study followed the standard European Organisation for Research and Treatment of Cancer (EORTC) four phase methodology: (I) generation of activities list, (II) construction of item list, (III) pre-testing, and (IV) field testing. This report covers phases I-III. To ensure cross-cultural validity, participants were recruited from different countries (The Netherlands, United Kingdom, Italy, Austria and Japan). In phase I, potential activities were identified based on a literature review and in-depth interviews with patients, proxies and healthcare professionals. In phase II, activities were turned into items, and translated into all required languages by the EORTC Translation Unit. In phase III, the item list was pre-tested in patient-proxy dyads. In accordance with predetermined decision rules to reduce items, final items were selected, and preliminary psychometric properties (i.e. factor structure, validity, reliability) were assessed. RESULTS Phase I (N=44 dyads) resulted in 59 IADL activities which were converted into 59 items in phase II. In phase III, N=85 dyads completed and reviewed this item list. The item list was subsequently reduced to 32 items. An exploratory factor analysis indicated several items measuring similar underlying constructs (e.g. domestic life and using computer/smartphone) showing acceptable to good (α≥0.7) internal consistency (range α=0.69–0.89). Seven items were less related to these underlying constructs (e.g. work or managing your own medication), and therefore single items. Construct validity, measured with known-group comparisons analyses between cognitively impaired and unimpaired patients, showed significant differences in scores between the two groups on some scales and several single items. CONCLUSION The currently developed EORTC IADL-BN32 questionnaire can be a valuable asset in assessing IADL functioning in brain tumour patients, but further validation in phase IV is required and is planned.

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Vittal, Prabhu Ravikala, N. Sriraam, C. K. Mala, and J. Saritha. "A Measure to Study Skin Reflectance using Non-Invasive Photosensor with Economic Design." International Journal of Biomedical and Clinical Engineering 4, no. 1 (January 2015): 51–63. http://dx.doi.org/10.4018/ijbce.2015010105.

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Non-invasive mode of clinical testing has created a major impact on the society and finds huge demand in the clinical domain. There are several instances where such approach receives more co-operations from the patient. Replacing the traditional practice with such non-invasive procedure requires appropriate clinical investigation and validations, specifically exact location of veins for intravenous applications like venepuncture and other medical procedures. Collection of blood samples for bilirubin test for new-borns, blood sugar level detection also needs a special attention where such non-invasive procedure is highly preferred. Such clinical methodology highly relies on the selection/design of photo sensor and works on the principles of light that gets scattered from the human skin. This specific research study attempts to measure the effect of the photo sensor on the skin reflection and how the properties can be exploited for bilirubin test to detect jaundice for new-borns. Neonatal jaundice often referred as hyperbilirubinemia which indicates the concentration of serum bilirubin levels in blood stream. The higher and lower bilirubin levels can cause irreversible brain damage which is referred as kernicterus. The yellowish spot due to bilirubin deposition in the neonatal skin tissue indicates the presence or absence of jaundice. Several attempts have been made in the recent past to develop non-invasive mode of measuring the blood concentration level for recognition of bilirubin levels. The proposed research study involves in measuring the skin reflectance using photo sensor and to measure the bilirubin concentration in a non-invasive mode. A GaAsP yellow LED with a wavelength of 590nm with TEPT5700 light sensors was applied and Arduino real time processor was interfaced to the circuitry. The system was designed in such a manner that the buzzer activation indicates the severity of the bilirubin concentration. The lab based circuitry was converted in to indigenous prototype and was tested with newborn in a real time mode. The clinical validation was found to be quite promising. It can be concluded that the designed system was found to be more economic and can introduce in the primary healthcare sector.

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Fleming, Irma D., Carla Tang, and Giavonni M. Lewis. "620 Outbreak of Carbapenem-Polymyxin-Quat-Resistant Acinetobacter Baumannii Associated with Mafenide Acetate shortages: An Interdisciplinary Approach to Eradication." Journal of Burn Care & Research 42, Supplement_1 (April 1, 2021): S164—S165. http://dx.doi.org/10.1093/jbcr/irab032.270.

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Abstract Introduction In the wake of Hurricane Maria, many US hospitals experienced massive drug shortages requiring substitution with alternative therapies. Our regional center experienced an increased incidence of Carbapenem-Polymyxin-Quat-Resistant Acinetobacter baumannii(CPQRA) infections, compared to a previous year of no infections. Here we describe a successful interdisciplinary approach to its eradication. Methods We conducted a retrospective review of CPQRA outbreaks for November and December 2018 in the burn ICU. De-identified data was collected and analyzed. In collaboration with the state’s department of health and epidemiology section, whole-genome sequencing was carried out on bacterial isolates. In addition, we instituted adenosine triphosphate (ATP) monitoring on all surfaces, a process of rapidly measuring actively growing microorganisms. Results Resistant Acinetobacter was isolated from five ICU patients, two of whom died with CPQRA bacteremia, producing a case-fatality rate of 40%. The two cases that died both suffered traumatic injuries with multiple fractures in addition to an average TBSA of 58%. Non-fatal cases suffered no other traumatic injuries and had an average TBSA of 51%.During this period, genitourinary irrigant (neomycin-Polymyxin B) and polymyxin ointment were the primary topical agents for wound care. Whole genome sequencing revealed a qacEdelta1 positive strain and identified the primary source as a patient that returned from a long-term care facility carrying the converted A. Baumannii infection. ATP testing also showed increased levels in patient rooms and surgical suite. Conclusions As a result of these findings, we achieved eradication by developing new and reinforcing traditional practices of infection control. This included UV light therapy to all ICU rooms and surgical suite, oversight of environmental services procedures, rigorous enforcement of hospital infection control procedures, auditing hand hygiene, increased efforts in antibiotic stewardship and discontinuing Polymyxin containing topicals. By January 2019 there were no new cases of CPQRA in the ICU. This study shows that the resistance and rapid spread of CPQRA can be controlled with the cooperation of hospital staff, environmental services, infection control, pharmacy, and the state’s department of health. With the coordinated efforts of all parties, we were able to successfully eradicate a virulent and fatal resistant A. baumannii strain.

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Fleming, Irma D., Carla Tang, Lois Remington, and Giavonni Lewis. "69 Outbreak of Carbapenem-polymyxin-quat-resistant Acinetobacter Baumannii Associated with Mafenide Acetate Shortages: An Interdisciplinary Approach to Eradication." Journal of Burn Care & Research 41, Supplement_1 (March 2020): S45. http://dx.doi.org/10.1093/jbcr/iraa024.073.

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Abstract Introduction In the wake of Hurricane Maria, many US hospitals experienced massive drug shortages requiring substitution with alternative therapies. Our regional center experienced an increased incidence of Carbapenem-Polymyxin-Quat-Resistant Acinetobacter baumannii(CPQRA) infections, compared to a previous year of no infections. Here we describe a successful interdisciplinary approach to its eradication. Methods We conducted a retrospective review of CPQRA outbreaks for November and December 2018 in the burn ICU. De-identified data was collected and analyzed. In collaboration with the state’s department of health and epidemiology section, whole-genome sequencing was carried out on bacterial isolates. In addition, we instituted adenosine triphosphate (ATP) monitoring on all surfaces, a process of rapidly measuring actively growing microorganisms. Results Resistant Acinetobacter was isolated from five ICU patients, two of whom died with CPQRA bacteremia, producing a case-fatality rate of 40%. The two cases that died both suffered traumatic injuries with multiple fractures in addition to an average TBSA of 58%.Non-fatal cases suffered no other traumatic injuries and had an average TBSA of 51%.During this period, genitourinary irrigant (neomycin-Polymyxin B) and polymyxin ointment were the primary topical agents for wound care. Whole genome sequencing revealed a qacEdelta1 positive strain and identified the primary source as a patient that returned from a long-term care facility carrying the converted A. Baumannii infection. ATP testing also showed increased levels in patient rooms and surgical suite. Conclusions As a result of these findings, we achieved eradication by developing new and reinforcing traditional practices of infection control. This included UV light therapy to all ICU rooms and surgical suite, oversight of environmental services procedures, rigorous enforcement of hospital infection control procedures, auditing hand hygiene, increased efforts in antibiotic stewardshipand discontinuing Polymyxin containing topicals. By January 2019 there were no new cases of CPQRA in the ICU. This study shows that the resistance and rapid spread of CPQRA can be controlled with the cooperation of hospital staff, environmental services, infection control, pharmacy and the state’s department of health. With the coordinated efforts of all parties, we were able to successfully eradicate a virulent and fatal resistant A. baumannii strain. Applicability of Research to Practice Describe an approach to eradicating resistant organisms and provide a roadmap to characterize the source, implement control measures to terminate an outbreak, and institute preventive measures.

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Leggett, L. M. W., and D. A. Ball. "Granger causality from changes in level of atmospheric CO<sub>2</sub> to global surface temperature and the El Niño–Southern Oscillation, and a candidate mechanism in global photosynthesis." Atmospheric Chemistry and Physics 15, no. 20 (October 21, 2015): 11571–92. http://dx.doi.org/10.5194/acp-15-11571-2015.

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Abstract. A significant difference, now of some 16 years' duration, has been shown to exist between the observed global surface temperature trend and that expected from the majority of climate simulations. For its own sake, and to enable better climate prediction for policy use, the reasons behind this mismatch need to be better understood. While an increasing number of possible causes have been proposed, the candidate causes have not yet converged. With this background, this paper reinvestigates the relationship between change in the level of CO2 and two of the major climate variables, atmospheric temperature and the El Niño–Southern Oscillation (ENSO). Using time-series analysis in the form of dynamic regression modelling with autocorrelation correction, it is shown that first-difference CO2 leads temperature and that there is a highly statistically significant correlation between first-difference CO2 and temperature. Further, a correlation is found for second-difference CO2 with the Southern Oscillation Index, the atmospheric-pressure component of ENSO. This paper also shows that both these correlations display Granger causality. It is shown that the first-difference CO2 and temperature model shows no trend mismatch in recent years. These results may contribute to the prediction of future trends for global temperature and ENSO. Interannual variability in the growth rate of atmospheric CO2 is standardly attributed to variability in the carbon sink capacity of the terrestrial biosphere. The terrestrial biosphere carbon sink is created by the difference between photosynthesis and respiration (net primary productivity): a major way of measuring global terrestrial photosynthesis is by means of satellite measurements of vegetation reflectance, such as the Normalized Difference Vegetation Index (NDVI). In a preliminary analysis, this study finds a close correlation between an increasing NDVI and the increasing climate model/temperature mismatch (as quantified by the difference between the trend in the level of CO2 and the trend in temperature).

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Yook, Soonhyun, Chaitanya Gupte, Zhixian Han, Eun Yeon Joo, Hea Ree Park, and Hosung Kim. "407 Explanatory analysis of polysomnography for the identification of sleep apnea hypopnea events using deep learning neural network." Sleep 44, Supplement_2 (May 1, 2021): A161—A162. http://dx.doi.org/10.1093/sleep/zsab072.406.

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Abstract Introduction Using deep learning algorithms, we investigated univariate and multivariate effects of four polysomnography features including heart rate (HR), electrocardiogram (ECG), oxygen saturation (SpO2) and nasal air flow (NAF) on the identification of sleep apnea and hypopnea events. This explanatory analysis that may clarify the sensitivity and specificity of those features to SAs and SHs have not been probed. Methods We studied 804 polysomonography samples from 704 patients with obstructive sleep apnea and 100 controls. The input data were converted into scalograms as 4-channel 2D images to train Xception networks. For training, 77,638 patches were sampled from the original 6-hour sleep data with 30-second time width. A 10% of these patches were segregated as the test-set. With each feature sets, we tested the following classifications: 1) normal vs apnea vs hypopnea; 2) normal vs. apnea+hypopnea; 3) normal vs. apnea; and 4) normal vs. hypopnea. Results SpO2 classified normal vs. apnea most accurately (98%), followed by NAF (85%), ECG (77%), and HR (63%). SpO2 also showed the highest accuracy in classifying normal vs. hypopnea (87%), and normal vs. apnea+hypopnea (96%) and three groups (82%). When the combination of four features were used, the classification accuracies were generally improved compared to use of SpO2 only (normal vs. apnea 99%; vs. hypopnea 89%; vs. apnea+hypopnea: 94%; three groups: 86%). Conclusion Deep learning with SpO2 or NAF feature most accurately classified apneas from normal sleep events, suggesting these features’ characterization of sleep apnea events. Oxygen desaturation, which is a typical pattern of hypopnea, was only the feature showing reliable accuracy in classifying hypopnea vs. normal. Nevertheless, combination of four polysomnography features could improve the identification of sleep apnea and hypopnea. Furthermore, classifying normal vs. apnea+hypopnea was more accurate than separately classifying three groups, suggesting deep learning approaches as the primary screen tool. Since the classification accuracy of using SpO2 was higher than any other features, developing a portable equipment measuring SpO2 and running deep learning algorithms has the potential for inexpensive, accurate diagnostics of obstructive sleep apnea syndrome. Support (if any) This study was supported by USC STEVENS CENTER FOR INNOVATION TECHNOLOGY ADVANCEMENT GRANTS (TAG), BrightFocus Foundation Award (A2019052S).

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