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Number of results: 25
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Abstract

Standard shipping documents such as bills of lading, charter parties, ship management contracts or cargo declarations are prepared to facilitate international maritime traffic. Their application improves the process of determining the content of various types of contracts, which is important in view of the increasing pace of economic turnover. The Baltic and International Maritime Council (BIMCO) plays a leading role in the development of such documents. The shipping documents it creates, as well as individual contractual clauses, are widely used in global shipping. BIMCO's activity, including its contribution to the creation of rules, general terms and standard contracts for international trade, is fundamental, and BIMCO itself can be considered the most important international maritime non-governmental organization in this respect.

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Authors and Affiliations

Cezary Łuczywek
ORCID: ORCID
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Abstract

The article focuses on selected aspects of the technical and economic analysis of the 0.8 MW agricultural biogas plant. The electrical power, generated in a cogeneration system, fed power to the neighbouring overhead power grid, Węgrów – Sokołów Podlaski, while the heat energy recovered from combustion gases and liquids cooling the engine was used to heat digesters, a residential building, drying room and farm buildings. The planned annual production equals c.a. 6400 MWh per year given the 8000 h of engine operation. The substrates used as input for the digestive chambers were as follows: fermented maize, pig slurry and liquid digestate pulp.
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Authors and Affiliations

Karol Tucki
Mikołaj Kominek
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Abstract

Based on laboratory tests of selected properties of secondary waste (ashes and dusts) from municipal waste incineration plants, the possibility of recovering some properties of waste in the process of filling the post-mining voids in the salt mine was assessed. The furnace bottom ash and the waste from the flue gas treatment from one of the national incineration plants were examined. The grain curves of dry waste and the density of the prepared mixtures were characterized. Twelve variants of the compositions of ash-based mixtures with varying proportions of the individual components were considered, taking into account both fresh water and brine. For each variant of the composition, the amount of redundant liquid appeared as well as the time of solidifying of the mixture to a certain strength and the compressibility values obtained. Considering the possibility of transporting mixtures in mines by means of pipelines at relatively long distances, and allowing the filling of large salt chambers to be filled and evenly filled, flow parameters were determined. In addition, the permeability of solidified waste samples was investigated, showing the potential for reducing the strength of the waste mass due to the action of water or brine. The technical feasibility of eliminating redundant liquid in the binding process has been confirmed, which is particularly important in salt mines. Preliminary values for the amount of binder (5%÷10%) to be added to the mixtures to obtain the specified strength properties of the artificially formed mass at Rc = 0.5 MPa. Attention was paid to the important practical aspect resulting from the rapid increase of this type of waste in the comming years in Poland and at the same time vast potential for their use in salt mining, where we have a huge capacity of salt chambers available.

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Authors and Affiliations

Krzysztof Skrzypkowski
Waldemar Korzeniowski
Katarzyna Poborska-Młynarska
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Abstract

Pyrolysis is often a first step in the incineration process, especially of the hazardous waste. One of examples of such installation is presented in the paper cylindrical pyrolysis chamber, applied in the incineration plant for medical waste. In the chamber the carbonisation of the waste takes place and the products, such as volatiles and carbonisate are burned in the cylindrical combustion chamber surrounding the pyrolysis chamber. Such configuration provides the heat transport from the flue gases to the carbonising material. To model the processes taking place in the pyrolysis chamber the energy and mass balance equations have been defined. The system of equations was solved for the exemplary material, such as wood sawdust, of a known thermophysical properties. Results are presented as diagrams of various parameters inside the two-dimension domain of the chamber.
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Authors and Affiliations

Krzysztof Wacławiak
Jan Niedziakiewicz
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Abstract

This paper presents a mechanical positioning system for a measuring microphone designed for acoustic studies in anechoic and reverberation chambers at the Department of Mechanics and Vibroacoustics, AGH. The results are discussed in the context of mechanical positioning and its impact on the outcome of the execution of individual measurement procedures. Moreover, areas for research were identified and solution concepts shown for further development of the automation of acoustic measurements in different research rooms in order to reduce the human involvement in them.

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Authors and Affiliations

Józef Felis
Tadeusz Kamisiński
Artur Flach
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Abstract

This article investigates the possibilities of the recovery of raw materials at the Kraków–Płaszów municipal wastewater treatment plant (WWTP). The materials include sand coming with raw sewage and delivered by septic tankers, after cleaning sewage systems. Following the Regulation of the Minister of Climate (January 2020), sand from grit chambers is classified in the waste catalog as waste, with the code of 19 08 02. (Journal of Laws of 2020, item 10). The purchase of very efficient units has optimized the grit chamber operation and minimized the amount of waste generated as well as being an odor nuisance. The paper presents a mass balance for sand collected at the WWTP. Due to the use of new sand separators, the amount of this waste has been reduced by 28%. The paper presents the sieve curves of sand collected at the wastewater treatment plant and during the cleaning of sewage wells, as well as for sand mixtures. The sand mixture was prepared to allow some variations in the grain size characteristics of the sand. The graining differentiation indexes and curvature indexes were calculated. In addition, in laboratory tests, the leachability of heavy metals and the content of dry matter (DM) and dry mineral matter (DMM) were determined. The laboratory tests confirmed the reduction of organic solids to a level below 3% of dry weight; the content of heavy metals remained below the level of detection. The experiments confirmed that sand from the WWTP can be used as fine-grained aggregate in the production of concrete.
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Authors and Affiliations

Justyna Górka
1
ORCID: ORCID
Dominika Poproch
2 3
ORCID: ORCID
Małgorzata Cimochowicz-Rybicka
1
ORCID: ORCID
Bartosz Łuszczek
4
ORCID: ORCID

  1. Faculty of Environmental Engineering and Energy, Cracow University of Technology, Kraków, Poland
  2. Doctoral School, Cracow University of Technology, Kraków, Poland
  3. Krakow Water, Kraków, Poland
  4. Kraków Water, Kraków, Poland
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Abstract

There has been considerable research done on multi-chamber mufflers used in the elimination of industrial venting noise. However, most research has been restricted to lower frequencies using the plane wave theory. This has led to underestimating acoustical performances at higher frequencies. Additionally, because of the space-constrained problem in most plants, the need for optimization of a compact muffler seems obvious. Therefore, a muffler composed of multiple rectangular fin-shaped chambers is proposed. Based on the eigenfunction theory, a four-pole matrix used to evaluate the acoustic performance of mufflers will be deduced. A numerical case for eliminating pure tones using a three-fin-chamber muffler will also be examined. To delineate the best acoustical performance of a space-constrained muffler, a numerical assessment using the Differential Evolution (DE) method is adopted. Before the DE operation for pure tone elimination can be carried out, the accuracy of the mathematical model must be checked using experimental data. The results reveal that the broadband noise has been efficiently reduced using the three-fin-chamber muffler. Consequently, a successful approach in eliminating a pure tone using optimally shaped three-fin-chamber mufflers and a differential evolution method within a constrained space has been demonstrated.
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Authors and Affiliations

Min-Chie Chiu
Ying-Chun Chang
Ho-Chih Cheng
Wei-Ting Tai
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Abstract

The investigations deal with mass transfer in simulated biomedical systems. The modification of classical diffusion chamber, sequential unit (SU) system, imitated different biomedical setups, boundary conditions. The experiments simulated: diffusion chamber (also with two barriers), transport through the membrane to the blood stream, transport from the stent eluting drug simultaneously to the vessel cells and to the blood stream. The concentrations of substances and the relative mass increases/decreases for SU systems indicate that the order of the curves follows the order of mass transfer resistances. The strong dependence of mass transfer rates versus type of diffusing substance was confirmed. The calculated drug fluxes, diffusion coefficients, permeation coefficients are convergent with literature. Permeation coefficients for complex sequential systems can be estimated as parallel connexion of constituent coefficients. Experiments approved functionality of the SU for investigations in a simulated biomedical system. Obtained data were used for numerical verification.

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Authors and Affiliations

Anna Adach
Natalia Kister
Andrzej Skassa
Aleksandra Bugalska
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Abstract

A system setup for measurements of acoustic field, together with the results of 3D visualisations of acoustic energy flow are presented in the paper. Spatial sampling of the field is performed by a Cartesian robot. Automatization of the measurement process is achieved with the use of a specialized control system. The method is based on measuring the sound pressure (scalar) and particle velocity(vector) quantities. The aim of the system is to collect data with a high precision and repeatability. The system is employed for measurements of acoustic energy flow in the proximity of an artificial head in an anechoic chamber. In the measurement setup an algorithm for generation of the probe movement path is included. The algorithm finds the optimum path of the robot movement, taking into account a given 3D object shape present in the measurement space. The results are presented for two cases, first without any obstacle and the other - with an artificial head in the sound field.

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Authors and Affiliations

Maciej Szczodrak
Bożena Kostek
Andrzej Czyżewski
Józef Kotus
Adam Kurowski
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Abstract

The aim of this study was to compare computer assisted sperm analysis (CASA) results of frozen thawed bull semen using three different chambers. Sixty bull frozen semen samples were thawed (37°C; 30 sec), extended in PBS (30×106 spermatozoa/mL; 37°C) and incubated (37°C; 2 min). Each semen sample was analyzed by CASA [total motility, progressive (pro)/ non-progressive/rapid/medium/slow movement spermatozoa, VCL, VSL, VAP, ALH, BCF, LIN, STR, WOB and hyperactive spermatozoa] using three different chambers: a Makler® chamber (MC; 10 μm); a Leja 4 chamber slide (LC; 20 μm); and a Glass slide covered with a coverslip (GSC; 10.3 μm). The Makler chamber gave higher values compared to both the LC and GSC for almost all examined parameters. No systematic effect was evident between LC and GSC for VCL, VSL, VAP, LIN, STR, WOB, ALH, and BCF. Method agreement between MC and LC was generally moderate, between MC and GSC poor and between LC and GSC moderate to good. In general, narrower limits of agreement were found in samples with lower values. In conclusion, the CASA outcomes could be influenced by the analysis chambers. This finding should be taken into consideration when comparing results from different laboratories.

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Authors and Affiliations

A. Basioura
G. Tsousis
C. Boscos
A. Lymberopoulos
I. Tsakmakidis
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Abstract

At the beginning of the year 2024, 65 years will have passed since the establishment of the Chamber of Experts of the Association of Polish Electrical Engineers (SEP). During this period, SEP underwent significant changes. Particularly serious changes in the conditions for practicing association expertises have occurred in recent years, along with dynamic economic and political changes in Poland. Expertise is strongly based on economic conditions and the ways in which scientific, technical and industrial competences are expanded and available in the society. In the past, these highest competencies were quite strictly limited to well-organized professional communities related to scientific and technical associations such as SEP, and federal bodies such as NOT. Competencies were also generated in the best industrial centres associated with academic polytechnic centres. Today the role of expertises in electrical, electronics and ICT engineering is undergoing significant changes.
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Authors and Affiliations

Maria Zastawny
1
Andrzej Skorupski
2
Ryszard S. Romaniuk
2

  1. SEP
  2. WUT, Poland
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Abstract

On the basis of mathematical modeling of fluid flow in vortex devices verification of use of detached-eddy simulation method in the swirling flows in vortex chamber superchargers is made. Research of a flow with use of different turbulence models was made for vortex chamber supercharger in two working points of the characteristic: with the open exit channel and closed. Verification has been spent on integrated parameters, and also on kinematic, by comparison of static pressure value of on the top end cover of the device. It is received that the hybrid turbulence model DES does not allow, as well as model SST precisely to predict value of vacuum on an axis of the vortex chamber. The error makes an order of 20 %. However, DES predicts almost correct, on 20 % big, than model SST, values of vacuum on an axis in a throat axial diffuser on an input in the vortex chamber. Besides, by means of DES it is possible to describe more adequately unsteady structures near to an axis of the vortex chamber, and also vortex core precession that does not allow to make SST turbulence model. By optimization of vortex devices, and vortex chamber superchargers in particular, simulation time essentially is better to use SST turbulence model with rotation-curvature correction.
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Authors and Affiliations

A. Rogovyi
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Abstract

The paper presents the first off-grid system designed to supply electricity to the equipment mounted on components of the district heating network in district heating chambers. The proposed off-grid system is equipped, among other things, with a turbine and a generator intended for electricity production. On-grid power supply is a common way of providing electricity with strictly defined, known and verified operating parameters. For off-grid power supply, however, there are no documented testing results showing such parameters. This paper presents selected results of tests and measurements carried out during the operation of an off-grid supply system powering the equipment installed in a district heating chamber. The values of voltage obtained from a turbine-driven generator are analysed in detail. The analysis results can be used as the basis for further works aiming to optimize the off-grid system of electricity supply to devices installed in district heating chambers.
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Authors and Affiliations

Robert Wiśniewski
1
Agata Kania
1
Wiesław Zima
2
Jan Taler
2

  1. Municipal Heat Supply Company, Jana Pawła II 188, 30-969 Kraków, Poland
  2. Cracow University of Technology, Department of Energy, Jana Pawła II 37, 31-864 Kraków, Poland
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Abstract

Shape optimization on mufflers within a limited space volume is essential for industry, where the equipment layout is occasionally tight and the available space for a muffler is limited for maintenance and operation purposes. To proficiently enhance the acoustical performance within a constrained space, the selection of an appropriate acoustical mechanism and optimizer becomes crucial. A multi-chamber side muffler hybridized with reverse-flow ducts which can visibly increase the acoustical performance is rarely addressed; therefore, the main purpose of this paper is to numerically analyze and maximize the acoustical performance of this muffler within a limited space.

In this paper, the four-pole system matrix for evaluating the acoustic performance - sound transmission loss (STL) - is derived by using a decoupled numerical method. Moreover, a simulated annealing (SA) algorithm, a robust scheme in searching for the global optimum by imitating the softening process of metal, has been used during the optimization process. Before dealing with a broadband noise, the STL's maximization with respect to a one-tone noise is introduced for the reliability check on the SA method. Moreover, the accuracy check of the mathematical models with respect to various acoustical elements is performed.

The optimal result in eliminating broadband noise reveals that the multi-chamber muffler with reverse-flow perforated ducts is excellent for noise reduction. Consequently, the approach used for the optimal design of the noise elimination proposed in this study is easy and effective.

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Authors and Affiliations

Min-Chie Chiu
Ying-Chun Chang
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Abstract

In order to investigate the effect of the surface shape on the performance of perforated panels, three non-flat shapes were considered for perforated panel with their absorption performance compared with the usual shape of the (flat) perforated panel. In order to simulate the absorption coefficient of a non-flat perforated panel, the finite element method was implemented by the COMSOL 5.3a software in the frequency domain. Numerical simulation results revealed that all the shapes defined in this paper improve the absorption coefficient at the mid and high frequencies. A and B shapes had a higher performance at frequencies above 800 Hz compared to the flat shape. Also, shape C had a relative superiority at all frequencies (1–2000 Hz) compared to the reference shape; this superiority is completely clear at frequencies above 800 Hz. The maximum absorption coefficient occurred within the 400–750 Hz range. After determining the best shape in terms of absorption coefficient (shape C), a perforated panel of 10 m2 using fiberglass fibers and desired structural properties was built, and then it was also subjected to a statistical absorption coefficient test in the reverberation chamber according to the standard. The results of the statistical absorption coefficient measurement showed that the highest absorption coefficient was 0.77 at the frequency of 160 Hz. Also, to compare the experimental and numerical results, these conditions were implemented in a numerical environment and the statistical absorption coefficient was calculated according to the existing relationships. A comparison of the numerical and laboratory results revealed acceptable agreement for these two methods in most frequency spectra, where the numerical method was able to predict this quantity with good accuracy.
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Authors and Affiliations

Zahra Hashemi
1
Ali Fahim
2
Mohammad Reza Monazzam
3

  1. Behbahan Faculty of Medical Sciences, Behbahan, Iran
  2. School of Engineering Science, College of Engineering, University of Tehran, Tehran, Iran
  3. School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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Abstract

In the family of iron-based alloys, ductile iron enjoys the highest rate of development, finding application in various industries. Ductile iron or the cast iron with spheroidal graphite can be manufactured by various methods. One of them is the Inmold spheroidization process characterized by different technological solutions, developed mainly to increase the process efficiency. So far, however, none of the solutions has been based on the use of a reactor made outside the casting mould cavity. The method of spheroidization inside the casting mould using a reaction chamber developed at the Foundry Research Institute is an innovative way of cast iron treatment. The innovative character of this method consists in the use of properly designed and manufactured reactor placed in the casting mould cavity. Owing to this solution, the Inmold process can be carried out in moulds with both horizontal and vertical parting plane. The study presents the results of examinations of the microstructure of graphite precipitates and metal matrix of castings after spheroidization carried out by the Inmold process using a reactor and mould with vertical parting plane. Special pattern assembly was made for the tests to reproduce plates with wall thicknesses of 3; 5; 7; 10; 20 and 30 mm. The content of residual magnesium was determined for all tested castings, while for castings of plates with a wall thickness equal to or larger than 10 mm, testing of mechanical properties was additionally performed.

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Authors and Affiliations

J. Kamińska
M. Angrecki
Z. Stefański
A. Palma
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Abstract

Recently, aluminum matrix syntactic foams (AMSFs) have become notably attractive for many different industrial areas like automotive, aerospace, construction and defense. Owing to their low density, good compression response and perfect energy absorption capacity, these advanced composite materials are also considered as strong alternatives to traditional particle reinforced composites and metal foams. This paper presents a promising probability of AMSF fabrication by means of industrial cold chamber die casting method. In this investigation, contrary to other literature studies restricted in laboratory scale, fully equipped custom-build cold chamber die casting machine was used first time and all fabrication steps were designed just as carried out in the real industrial high pressure casting applications. Main casting parameters (casting temperature, injection pressure, piston speed, filler pre-temperature and piston waiting time) were optimized in order to obtain flawless AMSF samples. The density alterations of the syntactic foams were analyzed depending upon increasing process values of injection pressure, piston speed and piston waiting time. In addition, macroscopic and microscopic investigations were performed to comprehend physical properties of fabricated foams. All these efforts showed almost perfect infiltration between filler particles at the optimized injection parameters.

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Authors and Affiliations

C. Bolat
A. Goksenli
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Abstract

The article presents the results of the research on the influence of the shape of reaction chamber on spheroidisation of cast iron produced with use of the inmold method. The amounts of nodular graphite precipitates in castings produced with the use of different reaction chambers have been compared.

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Authors and Affiliations

P. Just
T. Pacyniak
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Abstract

The effectiveness of cast iron spheroidization with FeSiMg master alloy by the traditional method and using a reaction chamber placed in the cavity of foundry mould was compared. The method of cast iron treatment in mould cavity using a reaction chamber is an innovative technology developed by the Foundry Research Institute in Krakow. The effectiveness of the spheroidization process carried out by both methods was checked on a series of test castings. The article also presents the results of metallographic examinations and mechanical testing, including the discussion of magnesium yield and its assimilation rate.

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Authors and Affiliations

J. Kamińska
M. Angrecki
Z. Stefański
A. Palma
E. Pamuła
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Abstract

The aim of the present study was to investigate whether the anterior chamber constitutes part of the normal migratory pathway of CD4+ and CD8+ lymphocytes in cattle and swine. The cells obtained from aqueous humor of cows and pigs were stained for CD4 and CD8 receptors, and subsequently analyzed with flow cytometry. The mean percentage of CD4+CD8-, CD4-CD8+ and CD4+CD8+ cells within the total lymphocyte population of the bovine anterior chamber was, respectively, 17.88, 12.64 and 27.26%. In turn, the mean values of these parameters in pigs were 1.77, 38.48 and 17.45, respectively. Among bovine and porcine CD4+CD8+ cells prevalent were those displaying CD4lowCD8low and CD4lowCD8high phenotypes, respectively. The results suggest that the anterior chamber in cattle and swine is an element in the normal migratory pathway of CD4+, CD8+ and CD4+CD8+ cells. Furthermore, the contribution of these subsets in the anterior chamber lymphocyte population can differ considerably between animal species.
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Authors and Affiliations

H. Ziółkowski
T. Maślanka
P. Socha
N. Ziółkowska
M. Dąbrowski
J. Małaczewska
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Abstract

In response to the problems of high-temperature gas intrusion and ablation in the expansion slit between ceramic tiles under complex flow conditions in the floating-wall combustion chamber, as well as the issue of hooks exceeding their service temperature, numerical simulations and analysis were conducted for this paper. The study revealed the mechanisms of gas intrusion and sealing and proposed two evaluation metrics for evaluating the cooling effect: the maximum temperature of the hook and the proportion of high-temperature area on the sidewall of the tile. Furthermore, the CRITIC weighting method was used to analyze the weight of these metrics. Based on this, the spacing, radius, and length effects on sealing and cooling effectiveness were studied, and multi-parameter calculations and optimization were performed. The results showed that the degree of gas intrusion in the transverse slit was significantly higher than that in the longitudinal slit. In addition, the sealing method of the jet impingement could effectively cool the downstream of both the transverse and longitudinal slit. The spacing of the jet impingement holes had the greatest impact on the cooling effect, followed by the radius and length. Finally, when the spacing of the holes is 10 mm, the length is 18.125 mm, and the radius is 1.6 mm, the cooling effect is optimal, with the proportion of high-temperature area on the side wall of the tile being 20.86% and the highest temperature of the hook reaching 836.02 K.
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Authors and Affiliations

Hong Shi
1
ORCID: ORCID
Rui Wang
1
ORCID: ORCID
Mingmin Chen
2
Jiao Wang
1
Jie Yuan
3
Qianwei Zhang
1
Kaijie Yang
3

  1. College of Energy & Power Engineering, Jiangsu University of Science and Technology, China
  2. College of Power and Energy Engineering, Harbin Engineering University, China
  3. College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, China
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Abstract

The article presents the assessment of the levels of radiated electromagnetic interference by commercial UAVs in the context of their popular use for various military tasks. The test was conducted in the frequency range from 30 MHz to 6 GHz, in an electromagnetically anechoic chamber, in accordance with the procedures provided for this type of checks. Apart from the control frequencies (which of course exceed the standards), it can be said that most of the tested UAVs using brushless motors do not exceed the emission levels specified by the military standard MIL-STD-461G. This opens the way to the use of COTS UAV as a carrier of electronic systems for the tasks of recognizing sources of radio signals in the investigated band.
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Authors and Affiliations

Rafał Przesmycki
1
ORCID: ORCID
Jarosław Michalak
1
ORCID: ORCID

  1. Military University of Technology, ul. Gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland
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Abstract

This article provides a thorough description of a range of non-standard application cases in which EMC laboratories can be used other than those traditionally associated with this kind of facilities. The areas covered here include investigations of: wireless and radio systems (such as IoT and broadband radio systems) also that require ultra-high operational dynamic range, emulation of interference-free and/or heavilymultipath propagation environment, shielding effectiveness of cabinets and materials (i.e. thin, light and flexible as textiles as well as heavy and thick such as building construction elements).

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Authors and Affiliations

Kamil Staniec
Zbigniew Jóskiewicz
Jarosław Janukiewicz
Tadeusz Więckowski

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