28 research outputs found
Experimental study of smog microphysical and optical vertical structure in the Silesian Beskids, Poland
This study presents the vertical profiles of aerosol optical and microphysical properties obtained from cable car
and ground-based measurements in the Silesian Beskids, Poland. The data were collected during a measurement
campaign between 25 February and March 11, 2018. An AE-51 micro-aethalometer and PMS7003 and OPC-N2
optical particle counters were mounted on the cable car and used to measure the profiles of equivalent of black
carbon (eBC) concentration and aerosol size distribution. In situ measurements of the optical properties of the
aerosols were obtained using an AE-31 aethalometer and photoacoustic devices. A prototype lidar was used to
determine the planetary boundary layer (PBL) height and the aerosol layers. In the middle phase of the study
(1–6 March 2018), significant night-time temperature inversions were observed. During the inversion period, the
parameters describing the amount of aerosols in the air increased significantly. The concentration of eBC
exceeded the level of 15 μg/m3 several times, with an average level of 5.39 ± 4.42 μg/m3. Conversely, the results
obtained in the first and third phases of the experiment were at the level of the aerosol background, being 1.45 ±
0.88 μg/m3 and 0.90 ± 0.95 μg/m3, respectively. Significant differences were also observed in the vertical
profiles of PM10 mass and eBC concentration. In the middle phase of the study, the profiles showed a significant
reduction in the concentration of pollutants with height, while in the first and third phases, there were slight
variations with height
Temperature Influence on the Functional Properties of Inductive Components with Mn-Zn Ferrite Cores
The paper presents the results of investigation of the temperature influence on the inductance and power losses in ferrite cores. Such effect can significantly influence the utility parameters of electronic devices, particularly in precision equipment. For example slight parameter change in this type of components in measuring devices can cause significant changes in output parameters. It is also equally important for mobile devices where increase of losses can limit the duration of service. Special measurement system composed of hysteresis graph, cryostat and PC was utilized to perform the experiment. The cores used during the investigation had closed magnetic circuit. In order to perform measurements of magnetic properties of the material, two sets of windings (magnetizing and sensing) were made on each core. The cores were placed in a cryostat, which was used to set the temperature value within the range from -20 to +50°C. The magnetic properties were measured by the hysteresis graph, to assess the influence of the temperature on the functional parameters
Temperature Influence on the Functional Properties of Inductive Components with Mn-Zn Ferrite Cores
The paper presents the results of investigation of the temperature influence on the inductance and power losses in ferrite cores. Such effect can significantly influence the utility parameters of electronic devices, particularly in precision equipment. For example slight parameter change in this type of components in measuring devices can cause significant changes in output parameters. It is also equally important for mobile devices where increase of losses can limit the duration of service. Special measurement system composed of hysteresis graph, cryostat and PC was utilized to perform the experiment. The cores used during the investigation had closed magnetic circuit. In order to perform measurements of magnetic properties of the material, two sets of windings (magnetizing and sensing) were made on each core. The cores were placed in a cryostat, which was used to set the temperature value within the range from -20 to +50°C. The magnetic properties were measured by the hysteresis graph, to assess the influence of the temperature on the functional parameters
Investigation of Magnetoelastic Properties of Ferrite Material under Low Magnetizing Fields Corresponding to Rayleigh Region
The following paper presents original results of study on the magnetoelastic properties of Ni-Zn (nickel-zinc) ferrite material under low magnetizing fields, corresponding to the so-called Rayleigh region. The investigated material was formed into frame-shape sample allowing to obtain uniform stress distribution. Special digitally controlled measurement system was utilized to perform investigation. Obtained results are presented in the paper. On the basis of them mathematical description of magnetoelastic effect in investigated material was developed as an extend of the Rayleigh model of magnetic hysteresis. Comparison of the experimental and modeling results indicates that the developed model is correct
Magnetoelastic Villari Effect in Ferrite Materials for Force and Stress Sensors Working in Low Magnetizing Field Region
The following paper presents the original results of investigation on the magnetoelastic properties of ferrite materials magnetized in low field region, which could be utilized in development of force and stress sensors. The objects of investigation were two ferrite materials (manganese-zinc Mn-Zn and nickel-zinc Ni-Zn). The magnetoelastic characteristics of the materials were investigated with the special measurement system, allowing measurement of magnetic parameters of the ferrite materials magnetized with low fields under the influence of the compressive stress. The obtained results indicate that there is a strong correlation between the magnetic properties of the material in low magnetizing field region, and applied mechanical stress, which allows development of the magnetoelastic stress or force sensor with ferrite core working in low magnetizing field region
New Methodology of Testing the Stress Dependence of Magnetic Hysteresis loop of the L17HMF Heat Resistant Steel Casting
This paper presents the results of investigation on the
tensile stresses dependence of magnetic characteristics
of the L17HMF steel casting. To ensure uniform stress
distribution in the sample for this investigation and the
closed magnetic circuit, the frame-shaped samples were
used. This is very important because it provides results
independent of the shape and dimensions of the sample.
On the columns of the sample both sensing and magnetizing
windings were made. It is highly recommended
to wound magnetizing and sensing windings on both
columns. Due to the specialized force reversing system,
compressive force generates the uniform tensile stresses
in the sample. Magnetic characteristics are measured
under these stresses by digitally controlled hysteresis
graph. On the base of results of measurements the magnetoelastic
characteristics of L17HMF steel casting were
determined. Determined this characteristic is necessary
to developed nondestructive testing method for monitoring
of industrial and energetic constructions with elements
made by L17HMF steel casting
Growth of Ternary and Quaternary ZnSe Compounds with Transition Metals by Chemical Vapor Transport
Halogen transport method was applied to grow the crystals of solid solutions of ZnSe and transition metals at the temperature far below the melting point and phase transition temperature. The large crystals of ZnMnSe, ZnFeSe, ZnNiSe and ZnFeSSe were obtained. The technological parameters and shape of the quartz reactor were chosen for growth of a large crystal by self-nucleation; the transparent quartz furnace enabled the control of nucleation by visual observation. The parameters of crystal growth were determined. The crystal quality was estimated by X-ray diffraction method. The composition of crystals was determined by electron microprobe analysis and energy dispersive X-ray fluorescence analysis
Magnetic Amorphous Micro-Force Sensor
In this paper the innovative method of microforce measurement based on air gap influence on magnetic circuits properties is presented. Magnetic ribbon core with air gap is put under transverse compressive stress perpendicular to the magnetic field direction generated by low-mass calibration weight. Change of the air gap induced by the force acting on the core causes change of its magnetic parameters. The possibility of utilization of various magnetic amorphous materials is investigated. Obtained results indicate a possibility of application of the developed sensor in microforce measurements
Precipitates in CdNiSe Crystals Grown by the Bridgman Method
Single crystals of CdNiSe alloys (x ranging from 0 to 0.075) were investigated using electron microprobe and X-ray diffraction. The analysis shows the presence of Ni-Se precipitates. The solubility limit of Ni is estimated to be 0.008
Functional Properties of Monolayer and Bilayer Graphene Hall-Effect Sensors
The paper describes the design, development, and investigation of a new type of Hall-effect sensors of a magnetic field made of graphene. The epitaxial growth of high-quality graphene structures was performed using a standard hot-wall CVD reactor, which allows for easy integration with an existing semiconductors production technologies. The functional properties of developed Hall-effect sensors based on graphene were investigated on special experimental setup utilizing Helmholtz coils as a source of reference magnetic field. Monolayer and quasi-free-standing bilayer graphene structures were tested. Results presented in the paper indicate that graphene is very promising material for development of Hall-effect sensors. Developed graphene Hall-effect sensor exhibit highly linear characteristics and high magnetic field sensitivity