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Prevalence of metabolic syndrome and improper nutritional status among adolescents

Agnieszka Ostromęcka Elżbieta Sochacka-Tatara Agnieszka Pac

Folia Medica Cracoviensia | 2023 | Vol. 63 | No 2 | 149-163 | DOI: 10.24425/fmc.2023.145919

Keywords metabolic syndrome adolescents nutritional status cholesterol glucose obesity

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Abstract

Prevalence of metabolic syndrome (MetS) and its components is a growing issue, including pediatric populations. However, because of many definitions used, it is difficult to assess the true fre-quency of these problems.
The aim of this study was to assess the prevalence of MetS and its components as well as the frequency of problems with inadequate nutritional status among adolescents.
One hundred ninety-six teenagers aged 15–18 years, living in Krakow and its vicinity were examined including measurement of blood pressure, anthropometric parameters and blood levels of cholesterol and glucose.
The prevalence of MetS was low and varied from 0.5% to 2.0% depending on the definition. Based on Cook’s definition of MetS, the most common components were hypertension (12.8%) and hypertriglycer-idemia (12.8%). Improper body weight (based on BMI) was found in 23.5% of adolescents, including 5.1% underweight, and 18.4% overweight or obese. According to the body fat percentage (BF%), 45.8% of the boys were underfat and 6.3% had too much body fat, while only 4% of the girls were below the BF% reference values and 15% above. All girls and 86.5% of boys had too low total body water. In conclusion, the prevalence of metabolic syndrome in population of Krakow adolescents was relatively low, but more than 12% of the adolescents had a hypertension or hypertriglyceridemia. Based on BMI most of adolescents were found to have adequate body weight, but examination of fat content in the body high prevalence of underfat was observed, especially among boys.

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Authors and Affiliations

Agnieszka Ostromęcka

Elżbieta Sochacka-Tatara

Agnieszka Pac

Chair of Epidemiology and Preventive Medicine, Faculty of Medicine, Jagiellonian University Medical College, Kraków, Poland

An influence of parameters of micro-electrical discharge machining on wear of tool electrode

Govindan Puthumana

Archive of Mechanical Engineering | 2017 | vol. 64 | No 2 | 149-163 | DOI: 10.1515/meceng-2017-0009

Keywords Micro-EDM tool wear ratio process inputs statistical methods main effects interactions regression analysis

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Abstract

To achieve better precision of features generated using the micro-electrical discharge machining (micro-EDM), there is a necessity to minimize the wear of the tool electrode, because a change in the dimensions of the electrode is reflected directly or indirectly on the feature. This paper presents a novel modeling and analysis approach of the tool wear in micro-EDM using a systematic statistical method exemplifying the influences of capacitance, feed rate and voltage on the tool wear ratio. The association between tool wear ratio and the input factors is comprehended by using main effect plots, interaction effects and regression analysis. A maximum variation of four-fold in the tool wear ratio have been observed which indicated that the tool wear ratio varies significantly over the trials. As the capacitance increases from 1 to 10 nF, the increase in tool wear ratio is by 33%. An increase in voltage as well as capacitance would lead to an increase in the number of charged particles, the number of collisions among them, which further enhances the transfer of the proportion of heat energy to the tool surface. Furthermore, to model the tool wear phenomenon, a egression relationship between tool wear ratio and the process inputs has been developed.

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Bibliography

[1] L. Tang and Y.F. Guo. Electrical discharge precision machining parameters optimization investigation on S-03 special stainless steel. The International Journal of Advanced Manufacturing Technology, 70(5-8):1369–1376, 2014. doi: 10.1007/s00170-013-5380-4.
[2] V.K. Meena and M.S. Azad. Grey relational analysis of micro-EDM machining of Ti-6Al-4V alloy. Materials and Manufacturing Processes, 27(9):973–977, 2012. doi: 10.1080/10426914.2011.610080.
[3] S.P. Sivapirakasam, J. Mathew, and M. Surianarayanan. Multi-attribute decision making for green electrical discharge machining. Expert Systems with Applications, 38(7):8370–8374, 2011. doi: 10.1016/j.eswa.2011.01.026.
[4] T. Muthuramalingam and B. Mohan. Influence of discharge current pulse on machinability in electrical discharge machining. Materials and Manufacturing Processes, 28(4):375–380, 2013. doi: 10.1080/10426914.2012.746700.
[5] Y.H. Guu, C.Y. Chou, and S.-T. Chiou. Study of the effect of machining parameters on the machining characteristics in electrical discharge machining of Fe-Mn-Al alloy. Materials and Manufacturing Processes, 20(6):905–916, 2005. doi: 10.1081/AMP-200060412.
[6] B. Jabbaripour, M.H. Sadeghi, Sh. Faridvand, and M.R. Shabgard. Investigating the effects of EDM parameters on surface integrity, MRR and TWR in machining of Ti–6Al–4V. Machining Science and Technology, 16(3):419–444, 2012.
[7] R. Mukherjee and S. Chakraborty. Selection of EDM process parameters using biogeography based optimization algorithm. Materials and Manufacturing Processes, 27(9):954–962, 2012. doi: 10.1080/10426914.2011.610089.
[8] S.S. Agrawal and V. Yadava. Modeling and prediction of material removal rate and surface roughness in surface-electrical discharge diamond grinding process of metal matrix composites. Materials and Manufacturing Processes, 28(4):381–389, 2013. doi: 10.1080/10426914.2013.763678.
[9] M.Ch. Panda and V. Yadava. Intelligent modeling and multiobjective optimization of die sinking electrochemical spark machining process. Materials and Manufacturing Processes, 27(1):10–25, 2012. doi: 10.1080/10426914.2010.544812.
[10] V.V. Reddy, A. Kumar, P.M. Valli, and C.S. Reddy. Influence of surfactant and graphite powder concentration on electrical discharge machining of PH17-4 stainless steel. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 37(2):641–655, 2015. doi: 10.1007/s40430-014-0193-4.
[11] B. Jabbaripour, M.H. Sadeghi, M.R. Shabgard, and H. Faraji. Investigating surface roughness, material removal rate and corrosion resistance in PMEDM of -TiAl intermetallic. Journal of Manufacturing Processes, 15(1):56–68, 2013. doi: 10.1016/j.jmapro.2012.09.016.
[12] A. Bhattacharya, A. Batish, and N. Kumar. Surface characterization and material migration during surface modification of die steels with silicon, graphite and tungsten powder in EDM process. Journal of Mechanical Science and Technology, 27(1):133–140, 2013. doi: 10.1007/s12206-012-0883-8.
[13] M.P. Jahan,Y.S.Wong, and M. Rahman. Acomparative experimental investigation of deep-hole micro-EDM drilling capability for cemented carbide (WC-Co) against austenitic stainless steel (SUS 304). The International Journal of Advanced Manufacturing Technology, 46(9-12):1145–1160, 2010. doi: 10.1007/s00170-009-2167-8.
[14] H.S. Lim, Y.S. Wong, M. Rahman, and M.K.E. Lee. A study on the machining of high aspect ratio micro-structures using micro-EDM. Journal of Materials Processing Technology, 140(1):318–325, 2003. doi: 10.1016/S0924-0136(03)00760-X.
[15] M.P. Jahan, Y.S. Wong, and M. Rahman. A comparative study of transistor and RC pulse generators for micro-EDM of tungsten carbide. International Journal of Precision Engineering and Manufacturing, 9(4):3–10, 2008.
[16] H.S. Liu, B.H. Yan, F.Y. Huang, and K.H. Qiu. A study on the characterization of high nickel alloy micro-holes using micro-EDM and their applications. Journal of Materials Processing Technology, 169(3):418–426, 2005. doi: 10.1016/j.jmatprotec.2005.04.084.
[17] F. Han, S. Wachi, and M. Kunieda. Improvement of machining characteristics of micro-EDM using transistor type isopulse generator and servo feed control. Precision Engineering, 28(4):378–385, 2004. doi: 10.1016/j.precisioneng.2003.11.005.
[18] F.L. Amorim and W.L. Weingaertner. The influence of generator actuation mode and process parameters on the performance of finish EDM of a tool steel. Journal of Materials Processing Technology, 166(3):411–416, 2005. doi: 10.1016/j.jmatprotec.2004.08.026.
[19] Y.S. Wong, M. Rahman, H.S. Lim, H. Han, and N. Ravi. Investigation of micro-EDM material removal characteristics using single RC-pulse discharges. Journal of Materials Processing Technology, 140(1):303–307, 2003. doi: 10.1016/S0924-0136(03)00771-4.
[20] N. Natarajan and P. Suresh. Experimental investigations on the microhole machining of 304 stainless steel by micro-EDM process using RC-type pulse generator. T he International Journal of Advanced Manufacturing Technology, 77(9-12):1741–1750, 2015. doi: 10.1007/s00170-014-6494-z.
[21] D.J. Kim, S.M. Yi, Y.S. Lee, and C.N. Chu. Straight hole micro EDM with a cylindrical tool using a variable capacitance method accompanied by ultrasonic vibration. Journal of Micromechanics and Microengineering, 16(5):1092, 2006. http://stacks.iop.org/0960-1317/16/i=5/a=031.
[22] Y. Li, M. Guo, Z. Zhou, and M. Hu. Micro electro discharge machine with an inchworm type of micro feed mechanism. Precision Engineering, 26(1):7–14, 2002. doi: 10.1016/S0141-6359(01)00088-5.
[23] J. Ramkumar, N. Glumac, S.G. Kapoor, and R.E. DeVor. Characterization of plasma in micro-EDM discharge using optical spectroscopy. Journal of Manufacturing Processes, 11(2):82–87, 2009. doi: 10.1016/j.jmapro.2009.10.002.
[24] K.P. Maity and R.K. Singh. An optimisation of micro-EDM operation for fabrication of microhole. The International Journal of Advanced Manufacturing Technology, pages 1–9, 2012. doi: 10.1007/s00170-012-4098-z.
[25] M.S. Azad and A.B. Puri. Simultaneous optimisation of multiple performance characteristics in micro-EDM drilling of titanium alloy. The International Journal of Advanced Manufacturing Technology, 61(9-12):1231–1239, 2012. doi: 10.1007/s00170-012-4099-y.
[26] B.B. Pradhan, M. Masanta, B.R. Sarkar, and B. Bhattacharyya. Investigation of electro-discharge micro-machining of titanium super alloy. The International Journal of Advanced Manufacturing Technology, 41(11-12):1094, 2009. doi: 10.1007/s00170-008-1561-y.
[27] H.S. Liu, B.H. Yan, F.Y. Huang, and K.H. Qiu. A study on the characterization of high nickel alloy micro-holes using micro-EDM and their applications. J ournal of Materials Processing Technology, 169(3):418–426, 2005. doi: 10.1016/j.jmatprotec.2005.04.084.
[28] F.L. Amorim and W.L. Weingaertner. The influence of generator actuation mode and process parameters on the performance of finish EDM of a tool steel. Journal of Materials Processing Technology, 166(3):411–416, 2005. doi: 10.1016/j.jmatprotec.2004.08.026.
[29] U. Natarajan, X.H. Suganthi, and P.R. Periyanan. Modeling and multiresponse optimization of quality characteristics for the micro-EDM drilling process. Transactions of the Indian Institute of Metals, 69(9):1675–1686, 2016. doi: 10.1007/s12666-016-0828-5.
[30] M.A.Ahsan Habib and M. Rahman. Performance analysis ofEDMelectrode fabricated by localized electrochemical deposition for micro-machining of stainless steel. The International Journal of Advanced Manufacturing Technology, 49(9-12):975–986, 2010. doi: 10.1007/s00170-009-2479-8.
[31] F.T. Weng, R.F. Shyu, and C.S. Hsu. Fabrication of micro-electrodes by multi-EDM grinding process. Journal of Materials Processing Technology, 140(1):332–334, 2003. doi: 10.1016/S0924-0136(03)00748-9.
[32] K. Takahata, N. Shibaike, and H. Guckel. High-aspect-ratio WC-Co microstructure produced by the combination of LIGA and micro-EDM. Microsystem Technologies, 6(5):175–178, 2000. doi: 10.1007/s005420000052.
[33] T.Y. Tai, T. Masusawa, and H.T. Lee. Drilling microholes in hot tool steel by using microelectro discharge machining. Materials Transactions, 48(2):205–210, 2007. doi: 10.2320/matertrans.48.205.
[34] D.D. DiBitonto, P.T. Eubank, M.R. Patel, and M.A. Barrufet. Theoretical models of the electrical discharge machining process. I. A simple cathode erosion model. Journal of Applied Physics, 66(9):4095–4103, 1989. doi: 10.1063/1.343994.
[35] P. Govindan and S.S. Joshi. Experimental characterization of material removal in dry electrical discharge drilling. International Journal of Machine Tools and Manufacture, 50(5):431–443, 2010. doi: 10.1016/j.ijmachtools.2010.02.004.
[36] S. Joshi, P. Govindan, A. Malshe, and K. Rajurkar. Experimental characterization of dry EDM performed in a pulsating magnetic field. CIRP Annals-Manufacturing Technology, 60(1):239–242, 2011. doi: 10.1016/j.cirp.2011.03.114.
[37] P. Govindan, A. Gupta, S.S. Joshi, A. Malshe, and K.P. Rajurkar. Single-spark analysis of removal phenomenon in magnetic field assisted dry EDM. J ournal of Materials Processing Technology, 213(7):1048–1058, 2013. doi: 10.1016/j.jmatprotec.2013.01.016.
[38] D.C. Montgomery. Design and Analysis of Experiments. JohnWiley & Sons, New York, 2008.

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Authors and Affiliations

Govindan Puthumana

Technical University of Denmark, Lyngby, Denmark

Simulation and numerical parameter identification of a biologically inspired bipedal robot with passive elements

Daniela Förg Heinz Ulbrich

Archive of Mechanical Engineering | 2010 | vol. 57 | No 2 | 149-163 | DOI: 10.2478/v10180-010-0008-9

Keywords multibody simulation bipedal robots biomechanics parameter identification

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Abstract

The goal of the project is to investigate the influence of elastic mechanisms on technical, bipedal locomotion. In particular, the paper presents the parameter identification for a biologically inspired two-legged robot model. The simulation model consists of a rigid body model equipped with rubber straps. The arrangement of the rubber straps is based on the arrangement of certain muscle groups in a human being. The parameters of the elastic elements are identified applying numerical optimisation. Thus two optimisation algorithms are investigated and compared with respect to robustness and computing time. Moreover, different objective functions are defined and discussed. The behaviour of the resulting configuration of the system is explored in terms of biomechanics.

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Authors and Affiliations

Daniela Förg

Heinz Ulbrich

Life after the end of the world: Post-apocalypse in Marek Baraniecki's “Cassandra's Head” and Jacek Dukaj's “The Old Axolotl”

Marta Błaszkowska

Ruch Literacki | 2020 | No 2 (359) | 149-163 | DOI: 10.24425/rl.2020.133845

Keywords Polish literature of the late 20th century science fiction and fantasy dystopia post-Apocalypse Lacanian orders of perception Jacques Lacan (1901–1981) Jacek Dukaj (b. 1974) Marek Baraniecki (b. 1954)

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Abstract

This is a critical reading of two Polish science-fiction novels of the post-Apocalypse subgenre, Cassandra’s Head by Marek Baraniecki and The Old Axolotl by Jacek Dukaj, with the help of concepts borrowed from the philosophical toolkit of Jacques Lacan. Each of the two books envisages an apocalyptic catastrophe and its consequences as well as the subsequent attempts to rebuild human civilization. The action in either novel is shaped by tensions between the Symbolic and the Real. The latter, though suppressed and shut out, keeps resurfacing, usually when it is least expected, leaving an indelible marks in the life of the survivors. An analysis of the handling of this conflict in the two novels offers a number of insights into the way these two fundamental modes (or, Lacanian orders) of human perception are integrated into the worlds of post-Apocalyptic fiction.

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Authors and Affiliations

Marta Błaszkowska

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Prevalence of metabolic syndrome and improper nutritional status among adolescents

Abstract

Authors and Affiliations

An influence of parameters of micro-electrical discharge machining on wear of tool electrode

Abstract

Bibliography

Authors and Affiliations

Simulation and numerical parameter identification of a biologically inspired bipedal robot with passive elements

Abstract

Authors and Affiliations

Life after the end of the world: Post-apocalypse in Marek Baraniecki's “Cassandra's Head” and Jacek Dukaj's “The Old Axolotl”

Abstract

Authors and Affiliations