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Abstract

In this study, the compressive deformation of crushed sandstone was tested using a crushed rock deformation-seepage test system, and the effects of various factors, including crushed rock grade, grade combination, water saturation status, and stress loading method (i.e., continuous loading or cyclic loading and unloading), on the compressive deformation of crushed sandstone was analyzed from four perspectives including stress-strain, bulking coefficient, deformation mechanism and energy dissipation. The results indicate that the stress-strain relations of crushed sandstone are closely associated with all factors considered, and are well represented by exponential functions. The strain observed for a given applied stress increased with increasing crushed rock grade throughout the loading period. Crushed sandstone grades were combined according to a grading index (n), where the proportion of large-grade rocks in the sample increased with increasing n. The bearing capacity of a water-saturated crushed sandstone sample with n = 0.2 was less than that of an equivalent dry sample for a given applied stress. The stress-strain curve of a water-saturated crushed sandstone sample with n = 0.2 under cyclic loading and unloading was similar to that obtained under continuous loading. Observation and discovery, the deformation mechanism of crushed sandstone was mainly divided into four stages, including crushing, rupture, corner detachment and corner wear. And 20% of the work done by testing machine is used for friction between the crushed sandstone with the inner wall of the test chamber, and 80% is used for the closing of the void between the crushed sandstone, friction sliding, crushing damage.

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Authors and Affiliations

Yanan Sun
Peisen Zhang
ORCID: ORCID
Wei Yan
ORCID: ORCID
Fenqian Yan
Junda Wu
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Abstract

Application of retractable enclosures enables to lengthen operation periods for outdoor swimming pools operated in the moderate climate zone. Enclosures allow to diminish energy losses from water in the pool to the environment. Thermal calculations for pools with retractable enclosures are difficult to carry out because of a number of required parameters which can only be estimated. One of them is the transmission of solar radiation through the enclosure. The present paper presents the method of estimation of this parameter for swimming pool enclosures made of polycarbonate panels that have multichannels structure. In order to calculate transmission, the methodology considering the multiples of solar reflection inside the enclosure and their absorption by polycarbonate has been elaborated. Calculation results for transmission of the enclosure were verified experimentally. Analysis of results show that the transmission depends strongly on the enclosure’s construction and on the direction of solar radiation on the enclosure. Mean transmission values of enclosure under research were determined both from calculations and experiment are equal to about 0.69 and 0.64, respectively. However, experimentally determined mean values of total transmission by parallel and perpendicular solar directions in relation to channel axes are equal to about 0.69 and 0.60, respectively.
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Bibliography

[1] Buonomano A., De Luca G., Figaj R.D., Vanoli L.: Dynamic simulation and thermo-economic analysis of a PhotoVoltaic/Thermal collector heating system for an indoor-outdoor swimming pool. Energ. Convers. Manage. 99(2015), 176–192.
[2] Chwieduk D.: Solar Energy of Building. Arkady, Warszawa 2011 (in Polish).
[3] Garnysz A., Zapałowicz Z.: Model of heat and mass transfer in swimming pool with roofing system. In: Proc. XX Int. Tagung “Forschung – Praxis – Didaktik im modernen Maschinenbau”. Stralsund, 21–24 Sept. 2011.
[4] Garnysz A., Zapałowicz Z.: Thermal calculations for swimming pool with the roofing system. In: Proc. 3rd Int. Conf. Low Temperature and Waste Heat Use in Energy Supply Systems – Theory and Practice. Bremen, 25–26 Oct. 2012, 72–78.
[5] Garnysz A., Zapałowicz Z.: Model of heat and mass transfer in swimming pools with roofing systems. Developments in Mechanical Engineering Vol. 5 (J.T. Cieslinski, J. Szymczak, Eds.), Gdansk University of Technology Publishers, Gdansk 2012, 49–58.
[6] Garnysz A., Zapałowicz Z.: Influence of environmental conditions on selected thermal parameters for the swimming pool with movable enclosure. Zeszyty Naukowe Politechniki Rzeszowskiej 290, Mechanika, RUTMech XXXI, 86(2014), 2/14, 207– 214 (in Polish).
[7] Garnysz A., Zapałowicz Z.: Comparison of characteristic thermal parameters for a swimming pool with retractable pool enclosures exploited in autumn and spring seasons. In: Proc. XV Int. Conf. on Heat Transfer and Renewable Sources of Energy (A.A. Stachel, D. Mikielewicz, Eds.), Wydawnictwo Uczelniane ZUT, Szczecin 2014, 301–306.
[8] Garnysz A.: Experimental study of thermal parameters for the swimming pool with movable transparent enclosure. Instal 1(2014), 33–36 (in Polish).
[9] Govaer D., Zarmi Y.: Analytical evaluation of direct solar heating of swimming pools. Sol. Energy 27(1981), 6, 529–533.
[10] Grudzinska M.: Mathematical models of solar transmission through transparent insulation. Fizyka budowli w teorii i praktyce VI(2011), 4, 21–26 (in Polish).
[11] http://energy.gov/energysaver/articles/swimming-pool-covers (accessed: July 2019).
[12] http://libart.com/ (accessed: 7 July 2019).
[13] http://www.alutherm.com.pl/ (accessed: 7 July 2019) (in Polish).
[14] http://www.aquashield.com (accessed: 7 July 2019).
[15] http://www.telescopicpoolenclosures.com (accessed: 7 July 2019).
[16] Katsaprakakis D.A.: Comparison of swimming pools alternative passive and active heating systems based on renewable energy sources in Southern Europe. Energy 81(2015), 738–753.
[17] Mousia A., Dimoudi A.: Energy performance of open air swimming pools in Greece. Energ. Buildings 90(2015), 166–172.
[18] Pluta Z.: Theoretical Basis of Photothermal Solar Energy Conversion. Oficyna Wydawnicza Politechniki Warszawskiej, Warszawa 2006 (in Polish).
[19] Desirable pool. E-fachowiec (2010), 3. http://www.efachowiec.info/ (accessed: 7 July 2019) (in Polish).
[20] Swimming pool covers, rolling devices and roofing. AstralPool catalog. http://www.astralpool.pl/dokumenty/331–362.pdf (accessed: 7 July 2019) (in Polish).
[21] Specialists in design, planning and build of aluminium, timber and PVCu pool enclosures. https://www.telescopicpoolenclosures.com/images/telescopic-poolenclosures- brochure.pdf (accessed: 7 July 2019).
[22] Pool technology. 2014/15. Basenhurt’s catalog. http://www.basenhurt.pl/katalog 2014/KatalogBasenHurt2014_15.pdf (accessed: 6 June 2015).
[23] EN 16153:2013+A1:2015 Light transmitting flat multiwall polycarbonate (PC) sheets for internal and external use in roofs, walls and ceilings. Requirements and test methods.
[24] ITB: Technical Assessment ITB AT-15-8917/2012. Płyty komorowe z poliweglanu Lexan Thermoclear LT2UV: 62RS, 82 RS, 102 RS, 105 RS, 163TS, 166RS, 165X, 169X, 206RS, 205X, 209X, 256RS, 255X, 259X, 253X and 325X, Warszawa 2013, ISBN 978-83-249-6236-8 (in Polish).
[25] Lexan Thermoclear: Polycarbonate cellular panels. Technical documentation . Sabic 02.2014 (in Polish).
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Authors and Affiliations

Zbigniew Zapałowicz
1
Agnieszka Garnysz-Rachtan
1

  1. West Pomeranian University of Technology in Szczecin, Faculty of Mechanical Engineering and Mechatronics, Department of Energy Technologies, Al. Piastów 19, 70-310 Szczecin, Poland
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Abstract

Functionally Graded Materials (FGM) are extensively employed for hip plant component material due to their certain properties in a specific design to achieve the requirements of the hip-joint system. Nevertheless, if there are similar properties, it doesn’t necessarily indicate that the knee plant is efficiently and effectively working. Therefore, it is important to develop an ideal design of functionally graded material femoral components that can be used for a long period. A new ideal design of femoral prosthesis can be introduced using functionally graded fiber polymer (FGFP) which will reduce the stress shielding and the corresponding stresses present over the interface. Herein, modal analysis of the complete hip plant part is carried out, which is the main factor and to date, very few research studies have been found on it. Moreover, this enhances the life of hip replacement, and the modal, harmonic, and fatigue analysis determines the pre-loading failure phenomena due to the vibrational response of the hip. This study deals with the cementless hip plant applying the finite element analysis (FEA) model in which geometry is studied, and the femoral bone model is based in a 3D scan.
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Bibliography

[1] S. Gross and E.W. Abel. A finite element analysis of hollow stemmed hip prostheses as a means of reducing stress shielding of the femur. Journal of Biomechanics, 34(8):995–1003, 2001. doi: 10.1016/s0021-9290(01)00072-0.
[2] D. Lin, Q. Li, W. Li, S. Zhou, and M.V. Swain. Design optimization of functionally graded dental implant for bone remodeling. Composites Part B: Engineering, 40(7):668–675, 2009. doi: 10.1016/j.compositesb.2009.04.015.
[3] G. Jin, M. Takeuchi, S. Honda, T. Nishikawa, and H. Awaji. Properties of multilayered mullite/Mo functionally graded materials fabricated by powder metallurgy processing. Materials Chemistry and Physics, 89(2-3):238–243, 2005. doi: 10.1016/j.matchemphys.2004.03.031.
[4] E. Yılmaz, A. Gökçe, F. Findik, H.O. Gulsoy, and O. İyibilgin. Mechanical properties and electrochemical behavior of porous Ti-Nb biomaterials. Journal of the Mechanical Behavior of Biomedical Materials, 87:59–67, 2018. doi: 10.1016/j.jmbbm.2018.07.018.
[5] A.T. Şensoy. M. Çolak, I. Kaymaz, and F. Findik. Optimal material selection for total hip implant: a finite element case study. Arabian Journal for Science and Engineering, 44:10293--10301, 2019. doi: 10.1007/s13369-019-04088-y.
[6] T.A. Enab and N.E. Bondok. Material selection in the design of the tibia tray component of cemented artificial knee using finite element method. Materials and Design, 44:454–460, 2013. doi: 10.1016/j.matdes.2012.08.017.
[7] H. Weinans, R.Huiskes, and H.J. Grootenboer. The behavior of adaptive bone-remodeling simulation models. Journal of Biomechanics, 25(12):1425–1441, 1992. doi: 10.1016/0021-9290(92)90056-7.
[8] J.A. Simões and A.T. Marques. Design of a composite hip femoral prosthesis. Materials & Design, 26(5):391–401, 2005. doi: 10.1016/j.matdes.2004.07.024.
[9] S. Tyagi and S.K. Panigrahi. Transient analysis of ball bearing fault simulation using finite element method. Journal of The Institution of Engineers (India): Series C, 95:309–318, 2014. doi: 10.1007/s40032-014-0129-x.
[10] I.S. Jalham. Computer-aided quality function deployment method for material selection. International Journal of Computer Applications in Technology, 26((4):190–196, 2006. doi: 10.1504/IJCAT.2006.010764.
[11] E. Karana, P. Hekkert, and P. Kandachar. Material considerations in product design: A survey on crucial material aspects used by product designers. Materials & Design, 29(6):1081–1089, 2008. doi: 10.1016/j.matdes.2007.06.002.
[12] M.F. Ashby. Materials Selection in Mechanical Design. Butterworth-Heinemann, Oxford, 1995.
[13] C. Vezzoli and E. Manzini. Environmental complexity and designing activity. In: Design for Environmental Sustainability, pages 215–217. Springer, London, 2008. doi: 10.1007/978-1-84800-163-3_11.
[14] M. Kutz. Handbook of Materials Selection. John Wiley & Sons, New York, 2002.
[15] R.V. Rao and B.K. Patel. A subjective and objective integrated multiple attribute decision making method for material selection. Materials & Design, 31(10):4738–4747, 2010. doi: 10.1016/j.matdes.2010.05.014.
[16] X.F. Zha. A web-based advisory system for process and material selection in concurrent product design for a manufacturing environment. The International Journal of Advanced Manufacturing Technology, 25:233–243, 2005. doi: 10.1007/s00170-003-1838-0.
[17] F. Giudice, G. La Rosa, and A. Risitano. Materials selection in the Life-Cycle Design process: a method to integrate mechanical and environmental performances in optimal choice. Materials & Design, 26(1):9–20, 2005. doi: 10.1016/j.matdes.2004.04.006.
[18] F. Findik and K. Turan. Materials selection for lighter wagon design with a weighted property index method. Materials & Design, 37:470–477, 2012. doi: 10.1016/j.matdes.2012.01.016.
[19] M. İpek, İ.H. Selvi, F. Findik, O. Torkul, and I.H. Cedimoğlu. An expert system based material selection approach to manufacturing. Materials & Design, 47:331–340, 2013. doi: 10.1016/j.matdes.2012.11.060.
[20] J.A. Basurto-Hurtado, G.I. Perez-Soto, R.A. Osornio-Rios, A. Dominguez-Gonzalez, and L.A. Morales-Hernandez. A new approach to modeling the ductile cast iron microstructure for a finite element analysis. Arabian Journal for Science and Engineering, 44:1221–1231, 2019. doi: 10.1007/s13369-018-3465-y.
[21] E. Yılmaz, F. Kabataş, A. Gökçe, and F. Fındık. Production and characterization of a bone-like porous Ti/Ti-hydroxyapatite functionally graded material. Journal of Materials Engineering and Performance, 29:6455--6467, 2020. doi: 10.1007/s11665-020-05165-2.
[22] E. Yılmaz, A. Gökçe, F. Findik, and H.Ö. Gulsoy. Assessment of Ti–16Nb– xZr alloys produced via PIM for implant applications. Journal of Thermal Analysis and Calorimetry, 134:7–14, 2018. doi: 10.1007/s10973-017-6808-0.
[23] H.F. El-Sheikh, B.J. MacDonald, and M.S.J. Hashmi. Material selection in the design of the femoral component of cemented total hip replacement. Journal of Materials Processing Technology, 122(2-3):309–317, 2002. doi: 10.1016/S0924-0136(01)01128-1.
[24] T.S. Rubak, S.W. Svendsen, K. Søballe, and P. Frost. Total hip replacement due to primary osteoarthritis in relation to cumulative occupational exposures and lifestyle factors: a nationwide nested case–control study. Arthritis Care & Research, 66(10):1496–1505. doi: 10.1002/acr.22326.
[25] İ. Çelik and H. Eroğlu. Selection application of material to be used in hip prosthesis production with analytic hierarchy process. Materials Science & Engineering Technology, 48(11):1125–1132, 2017. doi: 10.1002/mawe.201700046.
[26] A. Aherwar, A. Patnaik, M. Bahraminasab, and A. Singh. Preliminary evaluations on development of new materials for hip joint femoral head. Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications, 233(5):885–899, 2019. doi: 10.1177/1464420717714495.
[27] A. Hafezalkotob and A. Hafezalkotob. Comprehensive MULTIMOORA method with target-based attributes and integrated significant coefficients for materials selection in biomedical applications. Materials & Design, 87:949–959, 2015. doi: 10.1016/j.matdes.2015.08.087.
[28] G. Bergmann, G. Deuretzbacher, M. Heller, F. Graichen, A. Rohlmann, J. Strauss, anf G.N. Duda. Hip contact forces and gait patterns from routine activities. Journal of Biomechanics, 34(7):859–871, 2001. doi: 10.1016/s0021-9290(01)00040-9.
[29] A.Z. Şenalp, O. Kayabasi, and H. Kurtaran. Static, dynamic and fatigue behavior of newly designed stem shapes for hip prosthesis using finite element analysis. Materials and Design, 28(5):1577–1583, 2007. doi: 10.1016/j.matdes.2006.02.015.
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Authors and Affiliations

Saeed Asiri
1
ORCID: ORCID

  1. Mechanical Engineering Department, Engineering College King Abdulaziz University, Jeddah, Saudi Arabia
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Abstract

This study focuses on the problem of mapping impervious surfaces in urban areas and aims to use remote sensing data and orthophotos to accurately classify and map these surfaces. Impervious surface indices and green space assessments are widely used in land use and urban planning to evaluate the urban environment. Local governments also rely on impervious surface mapping to calculate stormwater fees and effectively manage stormwater runoff. However, accurately determining the size of impervious surfaces is a significant challenge. This study proposes the use of the Support Vector Machines (SVM) method, a pattern recognition approach that is increasingly used in solving engineering problems, to classify impervious surfaces. The research results demonstrate the effectiveness of the SVM method in accurately estimating impervious surfaces, as evidenced by a high overall accuracy of over 90% (indicated by the Cohen’s Kappa coefficient). A case study of the “Parkowo-Lesne” housing estate in Warsaw, which covers an area of 200,000 m², shows the successful application of the method. In practice, the remote sensing imagery and SVM method allowed accurate calculation of the area of the surface classes studied. The permeable surface represented about 67.4% of the total complex and the impervious surface corresponded to the remaining 32.6%. These results have implications for stormwater management, pollutant control, flood control, emergency management, and the establishment of stormwater fees for individual properties. The use of remote sensing data and the SVM method provides a valuable approach for mapping impervious surfaces and improving urban land use management.
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Authors and Affiliations

Janusz Sobieraj
1
ORCID: ORCID
Marcos Fernández Marín
2
ORCID: ORCID
Dominik Metelski
3
ORCID: ORCID

  1. Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16,00-637 Warsaw, Poland
  2. Universitat Politccnica de Valcncia, Department of Computer Science and Artificial Intelligence,46980 Paterna (Valencia), Spain
  3. University of Granada, Faculty of Economics and Business Sciences, Campus Cartuja, 18071Granada, Spain
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Abstract

During four Polish Geodynamical Expeditions to West Antarctica between 1979 and 1991, seismic measurements were made along 21 deep refraction profiles in the Bransfield Strait and along the coastal area of Antarctic Peninsula using explosion sources. Recordings were made by 16 land stations and 8 ocean bottom seismometers. Good quality recordings were obtained up to about 250 km distance. This allowed a detailed study of the seismic wave field and crustal structure. Three-dimensional tomographic inversion was carried out using first arriv­als from the complete data set including off-line recordings. As a result, we obtained a 3-D model of the P-wave velocity distribution in the study area. In the area adjacent to the Antarctic Peninsula coast, sedimentary cover of 0.2 to 3 km thickness was found, whereas in the shelf area and in the Bransfield Strait sedimentary basins with thickness from 5 to 8 km were observed. In the Bransfield Strait a high velocity body with Vp > 7.5 km/s was found at 12 km depth. The use of the off-line data allowed for determination of the horizontal extent of the body. The thickness of the crust varies from more than 35-40 km in the coastal area south of the Hero Fracture Zone to 30-35 km in the area of Bransfield Strait and South Shetland Islands and about 12 km in the Pacific Ocean NW of South Shetland Islands.

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Authors and Affiliations

Piotr Środa
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Abstract

Unification of laws on carriage of goods by sea on the international plane is likely the most sensible way to avoid conflict of laws and conflict of jurisdiction. Nevertheless, application of conflict-of-lawrules may still be inevitable.

Since 17 December 2009 the primary source of conflict-of-law rules has been Regulation (EC) no. 593/2008 of the European Parliament and of the Council of 17 June 2008 on the law applicable to contractual obligations (Rome I). This Regulation prompted a major reform of Polish private international law; the new law was enacted on 4 February 2011 and entered into force on 16 May 2011. Currently, as the Author points out, the flag of the vessel is no longer relevant as a potential connecting factor in shipping contracts.

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Authors and Affiliations

Iwona Zużewicz-Wiewiórowska
ORCID: ORCID

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