Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 43
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

We propose a Bayesian approach to estimating productive capital stocks and depreciation rates within the production function framework, using annual data on output, employment and investment only. Productive capital stock is a concept related to the input of capital services to production, in contrast to the more common net capital stock estimates, representing market value of fixed assets. We formulate a full Bayesian model and employ it in a series of illustrative empirical examples. We find that parameters of our model, from which the time-path of capital is derived, are weakly identified with the data at hand. Nevertheless, estimation is feasible with the use of prior information on the production function parameters and the characteristics of productivity growth. We show how precision of the estimates can be improved by augmenting the model with an equation for the rate of return.
Go to article

Authors and Affiliations

Jakub Boratyński
1
Jacek Osiewalski
2

  1. University of Lodz, Lodz, Poland
  2. Cracow University of Economics, Cracow, Poland
Download PDF Download RIS Download Bibtex

Abstract

In this study, the noise sources to which a coal miner, who works at the Kurul panel of Kilimli Colliery, Zonguldak, was exposed were investigated. These sources were positioned at different points from the surface to the workface. Noise levels were measured according to the working periods of the coal miners around the machines. The results were evaluated under the Turkish Noise Regulation. The critical exposure times in which the coal miners could work without the use of personal protective equipment were examined according to the noise values to which they were exposed. In addition, the personal noise exposure values of the machine operators (boring machine, electro-hydraulic drill, and pick hammer) were determined during the development works. Two different types of noise measurements, with a microphone at the ear level and inside the ear protector, were conducted. The results obtained when the microphone of the personal dosimeter was at ear level, were found to be 15 dBA higher than those when the microphone was inside the ear protector. As a result, the selection methods of ear protectors were analyzed. Recommendations were given for those working on the risky tasks at the panel.
Go to article

Authors and Affiliations

Ilknur Erol
1
ORCID: ORCID
Okan Su
2
ORCID: ORCID

  1. Çukurova University, Dept. of Mining Engineering, Adana, Türkiye
  2. Zonguldak Bülent Ecevit University, Dept. of Mining and Mineral Extraction, Zonguldak, Türkiye
Download PDF Download RIS Download Bibtex

Abstract

The article is the result of a project aimed at developing and implementing a design of composite accessories for support in excavations located in underground hard coal mines. The research team verified the possibility of using elements made of prefabricated composite structural profile as an alternative to steel and reinforced concrete lining elements used to improve support’s stability and protect against rockfall.
This paper includes a research experiment on the possibilities of using a composite C-profile element as lining made in the pultrusion technology with a longitudinal position of the roving. The prefabricated structural profiles were adapted to the function by designing seatings for fitting the flanges for arch support’s V-profiles. Prototypes of these elements were subjected to bench tests in compliance with the guidelines for testing mesh linings. In addition, computer simulations using the finite element method were carried out.
The values obtained during the tests were compared with the requirements for lightweight mesh and included the Polish standard PN-G-15050 and reinforced A-type concrete lining defined in the standard ­PN-G-06021. The team determined the areas where material strength exceeded and the structure was damaged. Despite the limited quantity of laboratory tests and lack of field tests in actual mining conditions, it was possible to address the argument of the research and determine whether it is possible to use C-profile made in the pultrusion technology as a lining element.
Go to article

Bibliography

[1] PN-G-15050:2018-01 Obudowa wyrobisk górniczych. Siatki okładzinowe zgrzewane.
[2] PN-G-06021:1997 Obudowa górniczych wyrobisk korytarzowych. Okładziny żelbetowe.
[3] M. Rotkegel. Wpływ sposobu montażu siatek okładzinowych na ich pracę. Przegląd Górniczy 70 (3), 79-85 (2014).
[4] J. Olszewski, Leksykon górniczy: praca zbiorowa. Katowice: Wydawnictwo Śląsk (1989).
[5] L . Nickels, The future of pultrusion. Reinf. Plast. 63 (3), 132-135 (2019). DOI: https://doi.org/10.1016/j.repl.2019.01.003
[6] G .G. Litwinskij, G.I. Gajko, N.I. Kyldyrkajew, Stalnyje ramnyje kriepi gornych wyrabotok. Kijew: Technika (1999).
[7] M. Grodzicki, M. Rotkegel, The concept of modification and analysis of the strength of steel roadway supports for coal mines in the Soma Basin in Turkey. Studia Geotechnica et Mechanica 40 (1), 38-45 (2018). DOI: https://doi.org/10.2478/sgem-2018-0006
[8] G .I. Gayko, M. Rotkegel, Issliedowanija niesuszcziej sposobnosti arocznoj kriepi pri razlicznych wariantach nagrużienia. Ugoł Ukrainy 2, 45-47 (2003).
[9] P. Horyl, R. Snuparek, P. Marsalek, K. Pacześniowski, Simulation of laboratory tests of steel arch support. Arch. Min. Sci. 62 (1), 63-176 (2017). DOI: http://doi.org/10.1515/amsc-2017-0012455
[10] H. Filcek, J. Walaszczyk, A. Tajduś, 1994. Metody komputerowe w geomechanice górniczej. Śląskie Wydawnictwo Techniczne (1994).
[11] R .D. Cook, D.S. Malkus, M.E. Plesha, R.J. Witt, Finite Element Modeling for Stress Analysis. John Wiley & Sons, Inc. (2002).
[12] CO SMOS/M User’s Guide, Los Angeles, Structural Research & Analysis Corp. (1999).
[13] E. Rusiński, Metoda elementów skończonych. System COSMOS/M. Wydawnictwo Komunikacji i Łączności (1994).
[14] A. Pytlik. Tests of steel arch and rock bolt support resistance to static and dynamic loading induced by suspended monorail transportation. Studia Geotechnica et Mechanica 41 (2), 81-92 (2019). DOI: https://doi.org/10.2478/sgem-2019-0009
[15] A. Pytlik. Comparative bench testing of steel arch support systems with and without rock bolt reinforcements. Arch. Min. Sci. 64 (4), 747-764 (2019). DOI: http://doi.org/10.24425/ams.2019.131064
[16] PN-G-15022:2018-11 Odrzwia podatne z kształtowników korytkowych – Wymagania wytrzymałościowe i badania.
[17] PN-G-15024:2017-10 Obudowa wyrobisk górniczych – Rozpory stalowe dwustronnego działania.
[18] PN-G-15026:2017-04 Obudowa wyrobisk górniczych – Strzemiona oraz złącza odrzwi z kształtowników korytkowych – Badania wytrzymałościowe.
[19] PN-G-14050:1998 Betonity fundamentowe do obudowy odrzwiami z łuków korytkowych wyrobisk górniczych poziomych i mało nachylonych – Wymagania i badania.
[20] PN-G-15092:1999 Kotwie górnicze – Badania.
[21] PN-G-15533:1997 Górnicza obudowa indywidualna – Stojaki cierne – Wymagania i badania.
Go to article

Authors and Affiliations

Marek Rotkegel
1
ORCID: ORCID
Jerzy Korol
1
ORCID: ORCID
Dagmara Sobczak
1
ORCID: ORCID

  1. Central Mining Institute, Plac Gwarków 1, 40-166, Katowice, Poland
Download PDF Download RIS Download Bibtex

Abstract

The aim of the study was to compare the extended high-frequency (EHF) hearing thresholds (10–16 kHz) in tinnitus and non-tinnitus ears, in a group of 98 patients with unilateral tinnitus and normal hearing at standard audiometric frequencies, in a 0.125–8 kHz range. It was found that a total of 65 patients (66%) had a hearing loss (a threshold shift >20 dB HL) in the EHF range and the EHF hearing loss occurred more frequently in the tinnitus ear than in the non-tinnitus ear. The data also indicate that the EHF thresholds increased with the patient’s age and were in most patients higher in the tinnitus ear than in the non-tinnitus ear.
Go to article

Authors and Affiliations

Lidija Ristovska
1
Zora Jachova
2

  1. City General Hospital “8th September” Department of Otorhinolaryngology, Division of Audiology, Skopje, North Macedonia
  2. Ss. Cyril and Methodius University in Skopje, Faculty of Philosophy, Institute of Special Education and Rehabilitation, Skopje, North Macedonia
Download PDF Download RIS Download Bibtex

Abstract

Magnetic properties of silicon iron electrical steel are determined by using standardized measurement setups and distinct excitation parameters. Characteristic values for magnetic loss and magnetization are used to select the most appropriate material for its application. This approach is not sufficient, because of the complex material behavior inside electrical machines, which can result in possible discrepancies between estimated and actual machine behavior. The materials’ anisotropy can be one of the problems why simulation and measurement are not in good accordance.With the help of a rotational single sheet tester, the magnetic material can be tested under application relevant field distribution. Thereby, additional effects of hysteresis and anisotropy can be characterized for detailed modelling and simulation.

Go to article

Authors and Affiliations

Gregor Bavendiek
Nora Leuning
ORCID: ORCID
Fabian Müller
Benedikt Schauerte
ORCID: ORCID
Andreas Thul
Kay Hameyer
ORCID: ORCID
Download PDF Download RIS Download Bibtex

Abstract

When the in-wheel motor is working, it will be affected by gravity, centrifugal force and electromagnetic force. These three kinds of mechanical loads will affect the mechanical stress characteristics of the in-wheel motor, and then affect the reliability of the in-wheel motor structure. In order to understand the influence of the above loads on the mechanical stress of the in-wheel motor, this paper takes a 15-kWbuilt-in permanent magnet in-wheel motor as the research object. Based on the establishment of the electromagnetic field and structure field coupling analysis model of the in-wheel motor, the mechanical stress of the in-wheel motor under different mechanical loads under rated and peak conditions are calculated and analyzed, and the influence of different mechanical loads on the stress and deformation of the in-wheel motor are studied. The research results show that, regardless of the rated operating condition or the peak operating condition, the in-wheel motor has the largest mechanical stress and deformation under the combined action of centrifugal force and electromagnetic force, and the smallest mechanical stress and deformation under the action of gravity only; under the same load (except for the case of gravity only), the stress and deformation of the in-wheel motor under the peak operating condition are larger than those under the rated operating condition; and the maximum stress and deformation of the in-wheel motor appear at the rotor magnetic bridge and the inner edge of the rotor, respectively, so the rotor is an easily damaged part of the in-wheel motor.
Go to article

Authors and Affiliations

Jie Xu
1
ORCID: ORCID

  1. Shandong University of Technology, School of Transportation and Vehicle Engineering, China
Download PDF Download RIS Download Bibtex

Abstract

As for a single line-to-ground fault in an ungrounded distribution system, the power-frequency current is too low to detect the fault. The transient current is more palpable than that at a power-frequency of 50 or 60 Hz. It is an effective method to estimate the fault using the transient fault current. To analyze and calculate the transient current of single line-to-ground faults, an equivalent circuit is proposed in this paper. This model is based on distributed parameters of power lines. And it contains positive, negative and zero sequence information. The transient equivalent circuit consists of equivalent resistance, equivalent inductance and equivalent capacitance. And the method of calculation the equivalent ele- ments is also submitted.MATLAB simulation results showthat the newtransient equivalent circuit has higher accuracy and stronger adaptability compared with the traditional one.

Go to article

Authors and Affiliations

Jun Jiang
Ling Liu
ORCID: ORCID
Download PDF Download RIS Download Bibtex

Abstract

We designed, fabricated, and evaluated a monopole water antenna (WA) filled with pure water. A 2.4 GHz patch antenna (PA) was used for measurement comparison, and the current density distribution and 3D field strength radiation distribution and reflection coefficient of the PA had a fundamental mode and a higher-order mode at 3.5 GHz, whose polarization was 90 degrees different. The 2.4 GHz monopole WA could receive only the fundamental mode of the PA. The 3.5 GHz WA could receive the higher-order mode of the PA by rotating the WA by 90 degrees. The transmission coefficient of the 2.4 GHz WA decreased with the square of the spacing, similar to the spatial propagation characteristics of electromagnetic waves. Almost the same results could be expected if planar or three-dimensional antennas were used instead of monopole electrodes.
Go to article

Authors and Affiliations

Koyu Chinen
1
Ichiko Kinjo
2

  1. GLEX, Yokohama, Japan
  2. Information and Communication System Engineering, Dept., National Institute of Technology, Okinawa College, Nago, Japan
Download PDF Download RIS Download Bibtex

Abstract

The studies on lexical availability deal with the available lexicon, the set of words that speakers have in the mental lexicon and which use is determined by the specific topic of the communication. This article presents the preliminary results of an exploratory research on the lexical availability in the Polish language of a sample of 147 students from 6 secondary schools in 6 Polish cities. Following a sociolinguistic methodology, the analysis considers the incidence of variables such as ‘sex’, ‘sociocultural level’ and ‘educational level’.
Go to article

Authors and Affiliations

Antonio María López González
1
ORCID: ORCID

  1. Uniwersytet Łódzki
Download PDF Download RIS Download Bibtex

Abstract

Progress in the industry is accompanied by the development of new materials and more efficient technological production processes. At present, additive production is becoming very attractive in all industries (research, development, production), which brings a number of advantages compared to subtractive methods (customization, production speed, control of material properties by users, etc.). The main advantage of 3D printing is the controlled deposition of material in defined places. Instead of demanding manual labour, fully automated production via computers leads to the manufacturing of complex components from materials whose production in conventional ways would be problematic or even impossible. Because these are new technologies, the main direction of research at present is to identify the basic physical properties of these materials under different types of loading.
The main goal of this article is to observe the dependence of the behaviour of the extruded material (thermoplastic reinforced with chopped carbon fibre) on the printing parameters (thickness of the lamina, the orientation of the fibres of the printed material, etc.). Based on published scientific works, it appears that these settings have a significant impact on the achieved physical properties. This is the reason why the authors decided to analyze the influence of these parameters on the basis of processed data from experimental measurements of mechanical properties in the MATLAB program. As this is FFF printing, an essential condition is to identify and specify the directional dependence of the behavior of the printed material. This physical phenomenon is a necessary condition for gradual knowledge for the purposes of a subsequent mathematical description of the material properties. According to the authors, for the purposes of modeling these materials in FEM-based programs, it is essential to define the directional dependence in the plane of the lamina.
Go to article

Authors and Affiliations

J. Majko
1
ORCID: ORCID
M. Handrik
1
ORCID: ORCID
M. Vaško
1
ORCID: ORCID
M. Sága
1
ORCID: ORCID
P. Kopas
1
ORCID: ORCID
F. Dorčiak
1
ORCID: ORCID
A. Sapietová
1
ORCID: ORCID

  1. University of Žilina, Faculty of Mechanical Engineering, Department of Applied Mechanics, Univerzitná 8215/1, 010 26 Žilina, Slovak Republic
Download PDF Download RIS Download Bibtex

Abstract

In this paper, we present an experimental setup developed for the calibration of dynamic force transducers which is based on the drop mass method. The traceability to SI units is realized through well-known mass characteristics and a reference shock accelerometer attached to that mass. Two approaches are proposed to analyse dynamic force employing a drop mass system. One approach depends on the inertial force of a falling mass while the other deals with the work-energy principle. Results of both approaches are then compared to the response of a statically calibrated force transducer. It is shown that the obtained maximum relative deviations between the response of force transducer and the first approach results are 1% while those of the second approach are 2%.
Go to article

Bibliography

[1] Fujii, Y., Isobe, D., Saito, S., Fujimoto, H., & Miki, Y. (2000). A method for determining the impact force in crash testing. Mechanical Systems and Signal Processing, 14(6), 959–965. https://doi.org/10.1006/mssp.1999.1272
[2] Fujii, Y. (2003). A method for calibrating force transducers against oscillation force. Measurement Science and Technology, 14(8), 1259–1264. https://doi.org/10.1088/0957-0233/14/8/310
[3] Hjelmgren, J. (2002). Dynamic Measurement of Force – A Literature Survey (SP Report 2002:34). SP Swedish National Testing and Research Institute SP Measurement Technology.
[4] Jun, Y., Yiqing, C., Xuan, H., & Xiao, Y. (2017). Impulse force calibration with dropped weight and laser vibrometer. IMEKO 23rd TC3, 13th TC5 and 4th TC22 International Conference, Finland, 19. https://www.imeko.org/publications/tc3-2017/IMEKO-TC3-2017-030.pdf
[5] Kobusch, M., Link, A., Buss, A., & Bruns, T. (2007). Comparison of shock and sine force calibration methods. IMEKO 20th TC3, 3rd TC16 and 1st TC22 International Conference, Maxico. https://www.imeko.org/publications/tc3-2007/IMEKO-TC3-2007-007u.pdf
[6] Satria, E., Takita, A., Nasbey, H., Prayogi, I. A., Hendro, H., Djamal, M., & Fujii, Y. (2018). New technique for dynamic calibration of a force transducer using a drop ball tester. Measurement Science and Technology, 29(12). https://doi.org/10.1088/1361-6501/aaeb71
[7] Schlegel, C., Kieckenap, G., Glöckner, B., Buß, A., & Kumme, R. (2012). Traceable periodic force calibration. Metrologia, 49(3), 224–235. https://doi.org/10.1088/0026-1394/49/3/224
[8] Sivaselvan, M. V., Reinhorn, A. M., Shao, X., & Weinreber, S. (2008). Dynamic force control with hydraulic actuators using added compliance and displacement compensation. Earthquake Engineering and Structural Dynamics, 37(15), 1785–1800. https://doi.org/10.1002/eqe.837
[9] Stanford, A. L., & Tanner, J. M. (1985). Work, Power, and Energy. In Physics for Students of Science and Engineering (pp. 109–144). Elsevier Inc. https://doi.org/10.1016/b978-0-12-663380-1.50008-2
[10] Vlajic, N., & Chijioke, A. (2017). Traceable calibration and demonstration of a portable dynamic force transfer standard. Metrologia, 54(4), S83–S98. https://doi.org/10.1088/1681-7575/aa75da
[11] Yang, Y., Zhao, Y., & Kang, D. (2016). Integration on acceleration signals by adjusting with envelopes. Journal of Measurements in Engineering, 4(2), 117–121. https://www.jvejournals.com/ article/16965/pdf
[12] Zhang, L., & Kumme, R. (2003). Investigation of interferometric methods for dynamic force measurement. In XVII IMEKO World Congress, Metrology in the 3rd Millennium, Croatia, 315–318.
[13] Zhang, L.,Wang, Y., & Zhang, L. (2010). Investigation of calibrating force transducer using sinusoidal force. AIP Conference Proceedings, 1253, 395–401. https://doi.org/10.1063/1.3455481
Go to article

Authors and Affiliations

Shaker A. Gelany
1
Gouda M. Mahmoud
1

  1. National Institute of Standards (NIS), Tersa St, El-Haram, PO Box 136, Code 12211, Giza, Egypt
Download PDF Download RIS Download Bibtex

Abstract

International standards from IEC and IEEE regulate power grid parameters such as theRMSvalue, frequency, harmonic and interharmonic distortion, unbalance or the presence of transients, that are important to assure the quality of distributed power. Standard IEC 61000-4-30 suggests the zero crossing algorithm for the measurement of the power grid frequency, but also states that different algorithms can be used. This paper proposes a new algorithm, the Fractional Interpolated Discrete Fourier Transform, FracIpDFT, to estimate the power grid frequency, suitable for implementation in resource limited embedded measurement systems. It is based on the non-integer Goertzel algorithm followed by interpolation at non-integer multiples of the DFT frequency resolution. The proposed algorithm is validated and its performance compared with other algorithms through numerical simulations. Implementation details of the FracIpDFT in an ARM Cortex M4 processor are presented along with frequency measurement results performed with the proposed algorithm in the developed system.
Go to article

Authors and Affiliations

Nuno M. Rodrigues
1
Fernando M. Janeiro
2
Pedro M. Ramos
1

  1. Instituto de Telecomunicações, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
  2. Instituto de Telecomunicações, Universidade de Évora, 7000-671 Évora, Portugal
Download PDF Download RIS Download Bibtex

Abstract

Eye fluids (aqueous humour and vitreous humour) may be helpful in estimating ante-mortem blood levels, since some parameters measured in these fluids have proved to be stable or to change in a predictable way after death. This would help in diagnosing the cause of death in some diseases or to evaluate ante-mortem blood levels in certain animals not easy to handle or with difficult access. In order to establish reference values of some parameters in blood and eye fluids (aqueous humour and vitreous humour), as well as the possible correlation among these three different fluids, various minerals and electrolytes (Ca, P, Mg, K, Na, Fe, Cr, Co, Ni, Cu, Zn, Se and Mo) were measured in 15 four to five year-old Lidia bulls, all dying after a period of significant stress and major exertion. Plasmatic values of Mg and P were much greater than reported in the literature. In general, mineral plasmatic values were greater than those found in ocular fluids (aqueous and vitreous), while Na, K and Cr were similar in the three fluids. We have verified the existence of correlations in P, Co and Mo among the three fluids measured, and between Se of plasma and vitreous humour. But the most marked correlations were observed in Mo (plasma -aqueous humour, r = 0.893, plasma-vitreous humour, r = 0.945, HA -HV, r = 0.849), in P (plasma-vitreous humour, r = 0.726) and in Co (plasma-vitreous humour, r = 879).

Go to article

Authors and Affiliations

J.R. González-Montaña
F. Escalera-Valente
J.M. Lomillos
A.J. Alonso
V. Gaudioso
M.E. Alonso
Download PDF Download RIS Download Bibtex

Abstract

African swine fever (ASF) is an acute, hemorrhagic, and devastating viral infectious disease that causes important economic losses to the swine industry. Currently, there are no effective vaccines or drugs available. Epigenetic mechanisms, especially cytosine methylation of cytosine- -phosphate-guanine (CpG) islands, have a significant impact on the life cycle of several viruses. Hence, drugs targeting DNA methylation may potentially be used for the treatment of ASF. Here, we selected the inner core, core shell, inner membrane, capsid, and external envelope membrane, to analyze the characteristics of CpG islands in the ASF virus (ASFV) genomes. Furthermore, we analyzed the promoters and CpG islands in the upstream regions of these genes. Results showed that the CpG islands of seven genes were conserved in the genomes of two genotype of ASFV strains, whereas the CpG islands of other genes were relatively conserved (ASFV strains differed mainly in the quantity of CpG islands). The different distribution of CpG islands in the genomes of different ASFV strains may affect their methylation status, which may in turn affect the regulation of viral gene expression, leading to different clinical outcomes. In addition, the predicted promoter regions based on the upstream sequences of most genes overlapped with CpG island positions. Methylation of the binding sites of the promoter regions inhibits the binding of the transcription factors to the promoters, thus inhibiting the activation of the promoters and limiting the synthesis of viral proteins. The results of this study provide a basis for exploring new antiviral therapeutic strategies from an epigenetic perspective.
Go to article

Authors and Affiliations

Y.-Y. Yu
1
M.-S. X
2
Q. Liu
1

  1. Nanchong Key Laboratory of Disease Prevention, Control and Detection in Livestock and Poultry, Nanchong Vocational and Technical College, Nanchong 637131, China
  2. Chongqing Three Gorges Vocational College, Wanzhou 404155, China
Download PDF Download RIS Download Bibtex

Abstract

The following article presents the results of selected properties of regranulates of polyamide 6.6, regranules of polyamide contaminated with polypropylene and regranules of polyamide contaminated with silicone. The tested materials came from the reprocessing of polyamides 6.6 originally derived from production of airbags from renowned world producers (material for the research came from production waste). The results of examination were referred to regranulates of uncontaminated polyamide but also obtained from waste from the production of these airbags.
The influence of impurities on properties of regranulates such as their density and melt flow index was assessed. The tests allowed to show a significant impact of impurities on the density but above all on the mass and volume flow rate index which ranged from 47 to 116 g/10 min.
In the case of standardized test specimens selected thermal and mechanical properties were analyzed. Differential scanning calorimetry was used to assess the impact of impurities on the thermal properties of polyamides, allowing primarily identification of materials and impurities (especially polypropylene) as well as characteristic temperatures and the enthalpy of melting of the materials being analyzed. The mechanical properties were assessed using a DMA device. DMA research allowed to determine changes in mechanical properties in a wide temperature range of tested materials. It allowed to obtain full characteristics of changes in material stiffness under the influence of two factors, i.e. temperature and content of impurities, like polypropylene or silicone.
Go to article

Authors and Affiliations

T. Stachowiak
1
ORCID: ORCID

  1. Częstochowa University of Technology, Faculty of Mechanical Engineering and Computer Science, Department of Technology and Automation, Częstochowa 42-200, 69 J.H. Dąbrowskiego Str., Poland
Download PDF Download RIS Download Bibtex

Abstract

The hydro-mechanical drawing combines conventional deep drawing and sheet hydroforming and is widely used in the automotive industry. In this study, we designed and fabricated an indigenous experimental set-up that is low cost, low weight and portable. This study investigated the deformation of sheet metals into hemispherical cup-shaped parts made of different materials, viz., aluminium 8011 alloys, copper C12200 and steel EN10130 alloys. The initial thickness of sheet metal was 0.4 mm, the most common thickness range used in automotive applications. The deformation behaviour in terms of dome height has been measured by varying the pressure of the fluids. Aluminium 8011 alloy sheets showed a maximum dome height of 11.46 mm at a pressure of 1.47 MPa with no rupture. Steel EN10130 sheets had a maximum dome height of 10.89 mm at a pressure of 9.31 MPa. It was concluded that the behaviours of materials are different in the hydro-mechanical drawing process than in mechanical tests. Copper C12200 sheet showed superior formability with a maximum dome height of 18.91 mm at a pressure of 7.06 MPa than other materials without fracture.
Go to article

Bibliography

[1] M.-G. Lee, Y.P. Korkolis, and J.H. Kim. Recent developments in hydroforming technology. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 229(4):572–596, 2015. doi: 10.1177/0954405414548463.
[2] C. Bell, J. Corney, N. Zuelli, and D. Savings. A state of the art review of hydroforming technology. International Journal of Material Forming, 13:789–828, 2020. doi: 10.1007/s12289-019-01507-1.
[3] F.T. Feyissa and D.R. Kumar. Enhancement of drawability of cryorolled AA5083 alloy sheets by hydroforming. Journal of Materials Research and Technology, 8(1):411–423, 2019. doi: 10.1016/j.jmrt.2018.02.012.
[4] L.H. Lang, Z.R. Wang, D.C. Kang, S.J. Yuan, S.H. Zhang, J. Danckert, and K.B. Nielsen. Hydroforming highlights: sheet hydro-forming and tube hydro-forming. Journal of Materials Processing Technology, 151(1-3):165–177, 2004. doi: 10.1016/j.jmatprotec.2004.04.032.
[5] K. Siegert, M. Häussermann, B. Lösch, and R. Rieger. Recent developments in hydroforming technology, Journal of Materials Processing Technology, 98(2):251–258, 2000. doi: 10.1016/S0924-0136 (99)00206-X.
[6] H. Hu, J.-F. Wang, K.-T. Fan, T.-Y. Chen, and S.-Y. Wang. Development of sheet hydroforming for making an automobile fuel tank. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 229(4):654–663, 2015. doi: 10.1177/0954405414554666.
[7] T. Nakagawa, K. Nakamura, and H. Amino. Various applications of hydraulic counter-pressure deep drawing. Journal of Materials Processing Technology, 71(1):160–167, 1997. doi: 10.1016/S0924- 0136(97)00163-5.
[8] H. Amino, K. Nakamura, and T. Nakagawa. Counter-pressure deep drawing and its application in the forming of automobile parts. Journal of Materials Processing Technology, 23(3):243–265, 1990. doi: 10.1016/0924-0136(90)90244-O.
[9] K. Nakamura and T. Nakagawa. Sheet metal forming with hydraulic counter pressure in Japan. CIRP Annals, 36(1):191–194, 1987. doi: 10.1016/S0007-8506(07)62583-9.
[10] S.H. Zhang, Z.R. Wang, Y. Xu, Z.T. Wang, and L.X. Zhou. Recent developments in sheet hydroforming technology. Journal of Materials Processing Technology, 151(1-3):237–241, 2004. doi: 10.1016/j.jmatprotec.2004.04.054.
[11] N. Abedrabbo, M.A. Zampaloni, and F. Pourboghrat. Wrinkling control in aluminum sheet hydroforming. International Journal of Mechanical Sciences, 47(3):333–358, 2005. doi: 10.1016/j.ijmecsci.2005.02.003.
[12] M. Koç and O.N. Cora. Introduction and state of the art of hydroforming. In: M. Koç (editor), Hydroforming for Advanced Manufacturing, pages 1–29, Elsevier, 2008. doi: 10.1533/9781845694418.1.
[13] M. Chen, X. Xiao, H. Guo, and J. Tong. Deformation behavior, microstructure and mechanical properties of pure copper subjected to tube hydro-forming. Materials Science and Engineering: A, 731 (2018) 331–343. doi: 10.1016/j.msea.2018.06.068.
[14] A.A. Emiru, D.K. Sinha, A. Kumar, and A. Yadav. Fabrication and characterization of hybrid aluminium (Al6061) metal matrix composite reinforced with SiC, B 4C and MoS 2 via stir casting. International Journal of Metalcasting, 2022. doi: 10.1007/s40962-022-00800-1.
[15] F. Hasan, R. Jaiswal, A. Kumar, and A. Yadav. Effect of TiC and graphite reinforcement on hardness and wear behaviour of copper alloy B-RG10 composites fabricated through powder metallurgy. JMST Advances, 4:1–11, 2022. doi: 10.1007/s42791-022-00043-5.
[16] K.S.A. Ali, V. Mohanavel, S.A. Vendan, M. Ravichandran, A. Yadav, M. Gucwa, and J. Winczek. Mechanical and microstructural characterization of friction stir welded SiC and B 4C reinforced aluminium alloy AA6061 metal matrix composites. Materials, 14 (11):3110, 2021. doi: 10.3390/ma14113110.
[17] L. Prasad, N. Kumar, A. Yadav, A. Kumar, V. Kumar, and J.~Winczek. In situ formation of ZrB 2 and its influence on wear and mechanical properties of ADC12 alloy mixed matrix composites. Materials, 14(9):2141, 2021. doi: 10.3390/ma14092141.
[18] S. Thiruvarudchelvan and F. Travis. An exploration of the hydraulic-pressure assisted redrawing of cups. Journal of Materials Processing Technology, 72(1):117–123, 1997. doi: 10.1016/S0924-0136 (97)00138-6.
[19] J.B. Kim, D.W. Lee, D.Y. Yang, and C.S. Park. Investigation into hydro-mechanical reverse redrawing assisted by separate radial pressure—process development and theoretical verification. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 211(6):451–462, 1997. doi: 10.1243/0954405971516419.
[20] M. Janbakhsh, M. Riahi, and F. Djavanroodi. A practical approach to analysis of hydro-mechanical deep drawing of superalloy sheet metals using finite element method. International Journal of Advanced Design and Manufacturing Technology, 6(1):1–7, 2013.
[21] E. Karajibani, R. Hashemi, and M. Sedighi. Forming limit diagram of aluminum-copper two-layer sheets: numerical simulations and experimental verifications. The International Journal of Advanced Manufacturing Technology, 90:2713–2722, 2017. doi: 10.1007/s00170-016-9585-1.
[22] S. Yaghoubi and F. Fereshteh-Saniee. An investigation on the effects of the process parameters of hydro-mechanical deep drawing on manufacturing high-quality bimetallic spherical-conical cups. The International Journal of Advanced Manufacturing Technology, 110:1805–1818, 2020. doi: 10.1007/s00170-020-05985-5.
[23] Z.P. Xing, S.B. Kang, and H.W. Kim. Softening behavior of 8011 alloy produced by accumulative roll bonding process. Scripta Materialia, 45(5):597–604, 2001. doi: 10.1016/S1359-6462(01)01069- 7.
[24] A. Hasanbaşoğlu and R. Kaçar. Resistance spot weldability of dissimilar materials (AISI 316L–DIN EN 10130-99 steels). Materials & Design, 28(6):1794–1800, 2007. doi: 10.1016/j.matdes.2006.05.013.
[25] B. Meng and M.W. Fu. Size effect on deformation behavior and ductile fracture in microforming of pure copper sheets considering free surface roughening. Materials & Design, 83:400–412, 2015. doi: 10.1016/j.matdes.2015.06.067.
[26] A.G. Olabi and A. Alaswad. Experimental and finite element investigation of formability and failures in bi-layered tube hydro-forming. Advances in Engineering Software, 42(10):815–820, 2011. doi: 10.1016/j.advengsoft.2011.05.022.
[27] M. Rahimi, P. Fojan, L. Gurevich, and A. Afshari. Aluminium Alloy 8011: Surface characteristics. Applied Mechanics and Materials, 719–720:29–37, 2015. doi: 10.4028/www.scientific.net/AMM.719-720.29.
[28] G. Pantazopoulos. Metallurgical observations on fatigue failure of a bent copper tube. Journal of Failure Analysis and Prevention, 9:270–274,2009. doi: 10.1007/s11668-009-9225-2.
[29] K.A. Annan, R.C. Nkhoma, and S. Ngomane. Resistance spot welding of a thin 0.7 mm EN10130: DC04 material onto a thicker 2.4 mm 817M40 engineering steel. Journal of Southern African Institute of Mining and Metallurgy, 121(10):1–7, 2021. doi: 10.17159/2411-9717/1597/2021.
[30] T. Maki and J. Cheng. Sheet hydroforming and other new potential forming technologies. In: IOP Conference Series: Materials Science and Engineering, 418:012117, 2018. doi: 10.1088/1757- 899X/418/1/012117.
[31] A.K. Sharma and D.K. Rout. Finite element analysis of sheet hydro-mechanical forming of circular cup. Journal of Materials Processing Technology, 209(3):1445–1453, 2009. doi: 10.1016/j.jmatprotec.2008.03.070.
Go to article

Authors and Affiliations

Binayak Nahak
1
ORCID: ORCID
Anil Kumar
2
ORCID: ORCID
Anshul Yadav
2
Jerzy Winczek
3
ORCID: ORCID

  1. Motilal Nehru National Institute of Technology Allahabad, Prayagraj – 211004, India
  2. Kamla Nehru Institute of Technology, Sultanpur – 228118, India
  3. Częstochowa University of Technology, Częstochowa, Poland
Download PDF Download RIS Download Bibtex

Abstract

The effectiveness of applied means of traffic noise protection can be determined through examining acoustic climate of the areas located near the communication routes. It allows to determine sound level in a specific area and determine the extent that its inhabitants are exposed to the effects of noise. The research and the analysis of the acoustic climate were carried out in the town of Podszosie, located in the vicinity of the S7 expressway. The aim of the research was: to determine the level of noise emitted by traffic on the S7 expressway, to determine the effectiveness of noise barriers installed in a given area, to determine the sound level in the vicinity of properties located in Podszosie, to determine whether the noise level in Podszosie is normal. The conducted research allowed the authors to determine the sound level prevailing in the study area, and to what extent its inhabitants are exposed to the effects of noise and how to prevent it. Showing the scale of the problem posed by noise from road transport. In addition to carrying out activities aimed at reducing its level, society should also be made aware of the harmful effects of its impact.
Go to article

Bibliography


[1] T.W. Collins, S. Nadybal, S.E. Grineski, “Sonic injustice: Disparate residential exposures to transport noise from road and aviation sources in the Continental”. US Journal of Transport Geography, 8, pp. 102–604. 2020. https://doi.org/10.1016/j.jtrangeo.2019.102604.
[2] H-J. Althaus, P. de Haan, R.W. Scholz, “Traffic noise in LCA Part 2: Analysis of existing methods and proposition of a new framework for consistent, context-sensitive LCI modeling of road transport noise emission”. International Journal of Life Cycle Assessment, 14(7), pp. 676–686. 2009. http://dx.doi.org/10.1007/s11367-009- 0117-1.
[3] K.S. Jraiw, “A computer model to assess and predict road transport noise in built-up areas”. Applied Acoustics, 21(2), pp. 147–162. 1987.
[4] Y. Lan, H. Roberts, M.P. Kwan, M. Helbich, “Transportation noise exposure and anxiety: A systematic review and meta-analysis”. Environmental Research, 191, pp. 110–118. 2020. https://doi.org/10.1016/j.envres.2020.110118.
[5] B. Schäffer, M. Brink, F. Schlatter, D. Vienneau, J.M. Wunderli, “Residential green is associated with reduced annoyance to road traffic and railway noise but increased annoyance to aircraft noise exposure”. Environment International, 143, pp. 105–885. 2020. https://doi.org/10.1016/j.envint.2020.105885.
[6] F. Alías, J.C. Socoró, R.M. Alsina-Pagès, “Wasn-based day–night characterization of urban anomalous noise events in narrow and wide streets”. Sensors 20(17), 4760, pp. 1–26. 2020. https://doi.org/10.3390/s20174760.
[7] Division of Process Automation and Logistics “Analysis of the causes and methods of noise prevention in road transport” Kazimierz Pulaski University of Technology and Humanities in Radom, 2018.
[8] P. Górski, T. Krukowicz, L. Morzyński, “Ocena możliwości zastosowania aktywnych metod redukcji hałasu w transporcie drogowym. Assessment of the possibility of using active noise reduction methods in road transport” (in [Polish]). Warszawa, CIOP-BIP, pp. 72–94. 2008.
[9] F.X. Bécot, “Tyre noise over impedance surfaces - Efficient application od the Equivalent Sources method”. Paris, HAL archives-ouvertes.fr, ISBN 91-7291-313-4. 2003.
[10] W. Gardziejczyk, “"Cicha" nawierzchnia drogowa jako sposób na ograniczenie poziomu hałasu od ruchu samochodowego. Low-noise pavement as a way of limitation of traffic noise level” (in [Polish]). Inżynieria Ekologiczna. Politechnika Białostocka, 40, pp. 65–73. 2014. https://doi.org/10.12912/2081139X.70.
[11] B. Galińska, J. Kopania, “Hałas drogowy, a skuteczność ekranów z oktagonalnymi reduktorami dźwięku. Noise road and effectiveness of noise barrier with octagonals sound reductor” (in [Polish]). Autobusy: technika, eksploatacja, systemy transportowe, 17(6), pp. 168–171. 2016.
[12] A. Ongel, “Inclusion of noise in environmental assessment of road transportation”. Environmental Modeling and Assessment, 21, pp. 181–192. 2016. https://doi.org/10.1007/s10666-015-9477-z.
[13] A. Suzuki, T. Tetsuo, E. Tsuyoshi, K. Toshfumi, T. Tomoshige, “Study of fan noise reduction for automotive Radiator Cooling Fans”. Tokio, Mitsubishi Heavy Industries, Ltd. Technical Review, 43(3), pp. 1–9. 2006.
[14] E. Beach, M. Gilliver, W. Williams, “Leisure noise exposure: participation trends, symptoms of hearing damage, and perception of risk”. International Journal of Audiology, 52(sup1), pp. 20–25. 2013. https://doi.org/10.3109/14992027.2012.743050.
[15] Z. Łukasik, A. Kuśmińska-Fijałkowska, J. Kozyra, S. Olszańska, “Analysis of investment processes in a transport environment and the aspect of financing transport means”. Proceedings of the 23nd International Conference Transport Means 2019, pp. 1579–1584. 2019.
[16] J. Gnap, B. Šarkan, V. Konečný, T. Skrúcaný, “The Impact of Road Transport on the Environment”. In: Sładkowski A. (eds) Ecology in Transport: Problems and Solutions. Lecture Notes in Networks and Systems, 124, pp. 251–309. Springer, Cham. 2020. https://doi.org/10.1007/978-3-030-42323-0_5.
[17] R. Slávik, J. Gnap, “Selected problems of night-time distribution of goods within city Logistics”. Transportation Research Procedia, 40, pp. 497–504. 2019. https://doi.org/10.1016/j.trpro.2019.07.072.
[18] L. Gagnom, G. Dore, M.J. Richard, “An overview of various new road profile quality evaluation criteria: part 1”. International Journal of Pavement Engineering, 16(3), pp. 224–238. 2015. https://doi.org/10.1080/10298436.2014.942814.
[19] P. Veselik, M. Sejkorova, A. Nieoczym, J. Caban, “Outlier identification of concentrations of pollutants in environmental data using modern statistical methods”. Polish Journal of Environmental Studies, 29(1), pp. 853–860. 2020. https://doi.org/10.15244/pjoes/112620.
[20] J. Ližbetin, M. Hlatká, L. Bartuška, “Issues concerning declared energy consumption and greenhouse gas emissions of FAME biofuels”. Sustainability, 10(9), pp. 25–30. 2018. https://doi.org/10.3390/su10093025.
[21] Kellner, F., Otto, A., “Allocating CO2 emissions to shipments in road freight transportation”. Journal of Management Control, 22(4), pp. 451–479. 2012. https://doi.org/10.1007%2Fs00187-011-0143-6.
[22] A Jevinger, J.A. Persson, “Consignment-level allocations of carbon emissions in road freight transport”. Transp. Res. Part D: Transp Environ, 48, pp. 298–315. 2016. https://doi.org/10.1016/j.trd.2016.08.001.
[23] W. Paszkowski, M. Dąbrowski, “The use of acoustic maps in modeling features of objects oriented on acoustic quality of the environment”. Proceedings of 17th International Multidisciplinary Scientific GeoConference. Informatics, geoinformatics and remote sensing. Cartography and GIS, 17(23), pp. 769–776. 2017. https://doi.org/10.5593/sgem2017/23/S11.096.
[24] G. Nowacki, I. Mitraszewska, T. Kamiński, A.Wierzejski An influence of infrasound and infrasound noise on the behaviour of drivers of mechanical vehicle, Journal of KONES Power train and Transport, Vol.14, No. 3 2007.
[25] Risk of low-frequency noise for drivers of road transport, Central Institute for Labor Protection – National Research Institute, Warsaw 2010.
Go to article

Authors and Affiliations

Zbigniew Łukasik
1
ORCID: ORCID
Aldona Kuśmińska-Fijałkowska
1
ORCID: ORCID
Jacek Kozyra
1
ORCID: ORCID
Sylwia Olszańska
2
ORCID: ORCID

  1. Faculty of Transport, Electrical Engineering and Computer Science, Kazimierz Pulaski University of Technology and Humanities in Radom, Radom, Poland
  2. Chair of Logistics and Process Engineering, University of Information Technology and Management in Rzeszow, Rzeszow, Poland
Download PDF Download RIS Download Bibtex

Abstract

Modeling and numerical analysis of the design of building structures, their technology, organization and management methods of construction processes are the subject of the work of many scientists in Poland. Schedule designers try to best reflect the reality of construction projects with the available methods, although this procedure is not always successful. One of the scheduling methods is the Time Coupling Methods (TCM), which can be refined using the predictive durations of the Multivariate Method of Statistical Models (MMSM) construction processes and standard deviations. A new scheduling method in the probabilistic approach was developed – Probabilistic Time Couplings Method I (PTCM I). At PTCM I, work is organized in such a way as to maintain the continuity of work of employees, as downtime of workers is disadvantageous and costly. The total duration of the new investment was forecasted and compared with the other methods of scheduling and with real time after its completion. The results clearly show that the developed methodology can be successfully used in scheduling construction works.
Go to article

Authors and Affiliations

Paulina Kostrzewa-Demczuk
1
ORCID: ORCID
Magdalena Rogalska
2
ORCID: ORCID

  1. Kielce University of Technology, Faculty of Civil Engineering and Architecture, Al. Tysiąclecia Państwa Polskiego 7, 25-314 Kielce, Poland
  2. Lublin University of Technology, Faculty of Civil Engineering and Architecture, Nadbystrzycka St. 40, 20-618 Lublin, Poland
Download PDF Download RIS Download Bibtex

Abstract

In the literature, researchers present construction projects as temporary self-organising coalition networks, composed of specialist entities that work towards set goals. The number of parties involved in the various processes during construction causes communications relations to be exceedingly complex and to change. The environment of a construction project is dynamic and complex, and self-organising communication networks are sensitive to institutional and social change. It becomes necessary to identify situations rooted in both insufficient communication during the carrying out of a project and its excess, which generates unnecessary cost. Effective control of information flow within self-organising communication networks through its planning and monitoring by project management can contribute to achieving project goals. This paper presents a proposal of an optimisation approach (in terms of minimising communication costs) to information flow planning that accounts for various constraints, on the example of a real-world case of building a housing complex in Poland.
Go to article

Authors and Affiliations

Ewelina Kania
1
ORCID: ORCID
Grzegorz Śladowski
2
ORCID: ORCID
Elżbieta Radziszewska-Zielina
3
ORCID: ORCID
Bartłomiej Sroka
1
ORCID: ORCID
Bartłomiej Szewczyk
2
ORCID: ORCID

  1. MSc. Eng., Cracow University of Technology, Faculty of Civil Engineering, ul. Warszawska 24, 31-155 Cracow, Poland
  2. PhD. Eng., Cracow University of Technology, Faculty of Civil Engineering, ul. Warszawska 24, 31-155 Cracow, Poland
  3. Prof. PhD. Eng., Cracow University of Technology, Faculty of Civil Engineering, ul. Warszawska 24, 31-155 Cracow, Poland
Download PDF Download RIS Download Bibtex

Abstract

This paper presents and analyses the results of a simulation of the acoustic field distribution in sectors of a 1024-element ring array, intended for the diagnosis of female breast tissue with the use of ultrasonic tomography. The array was tested for the possibility to equip an ultrasonic tomograph with an additional modality - conventional ultrasonic imaging with the use of individual fragments (sections) of the ring array. To determine the acoustic field for sectors of the ring array with a varying number of activated ultrasonic transducers, a combined sum of all acoustic fields created by each elementary transducer was calculated. By the use of MATLAB software, a unique algorithm was developed, for a numerical determination of the distribution of pressure of an ultrasonic wave on any surface or area of the medium generated by the concave curvilinear structure of rectangular ultrasound transducers with a geometric focus of the beam. The analysis of the obtained results of the acoustic field distribution inside the ultrasonic ring array used in tomography allows to conclude that the optimal number of transducers in a sector enabling to obtain ultrasound images using linear echographic scanning is 32 ≤ n ≤ 128, taking into account that due to an increased temporal resolution of ultrasonic imaging, this number should be as low as possible.

Go to article

Authors and Affiliations

Wiktor Staszewski
Tadeusz Gudra
Krzysztof J. Opieliński
Download PDF Download RIS Download Bibtex

Abstract

In this work we present the design and the manufacturing processes, as well as the acoustics standardization tests, of an acoustic barrier formed by a set of multi-phenomena cylindrical scatterers. Periodic arrangements of acoustic scatterers embedded in a fluid medium with different physical properties are usually called Sonic Crystals. The multiple scattering of waves inside these structures leads to attenuation bands related to the periodicity of the structure by means of Bragg scattering. In order to design the acoustic barrier, two strategies have been used: First, the arrangement of scatterers is based on fractal geometries to maximize the Bragg scattering; second, multi-phenomena scatterers with several noise control mechanisms, as resonances or absorption, are designed and used to construct the periodic array. The acoustic barrier reported in this work provides a high technological solution in the field of noise control.

Go to article

Authors and Affiliations

Sergio Castiñeira-Ibáñez
Constanza Rubio
Vicent Romero-García
Juan Vicente Sánchez-Pérez
Luís Miguel García-Raffi
Download PDF Download RIS Download Bibtex

Abstract

Research over a three year period indicated that P. ramorum occurred rarely in Poland on Rhododendron spp., in spite of established monitoring in nurseries, trade stands, forest and water from early spring to late autumn each year. The pathogen was not found in forests on Vaccinium vitisidaea, Calluna vulgaris, Fagus sylvatica and Quercus rubra, proving its limited spread. The species was detected, however, from 2 rivers. P. citricola was isolated from most of surveyed plants. Besides this P. cactorum, P. cinnamomi, P.citrophthora and P. nicotianae var. nicotianae were isolated from diseased plants. Additionally Pestalotia sydowiana, species of Fusarium, Botrytis cinerea and Trichoderma were often found in diseased plant tissues. Laboratory and glasshouse research showed slight differences in colonization of plants by P. ramorum and P. citricola. However, taking into account the range of host plants, and frequency of pathogen occurrence in infected plant material and water, it became clear that P. citricola poses a much greater danger than P. ramorum to the natural environment in Poland.

Go to article

Authors and Affiliations

Leszek B. Orlikowski
Tomasz Oszako
Aleksandra Trzewik
Teresa Orlikowska
Download PDF Download RIS Download Bibtex

Abstract

In this paper a DC-link voltage balancing strategy for multilevel Cascaded H-Bridge (CHB) converter is proposed. Presented solution bases on optimal choice of active vector durations in Space-Vector Pulse Width Modulation (SV-PWM). It makes it possible to DC-link voltages control and to properly generate the output voltage vector in the case of DC-link voltage unbalance. Results of simulation and experimental researches on proposed control strategy are presented in the paper.
Go to article

Authors and Affiliations

Arkadiusz Lewicki

This page uses 'cookies'. Learn more