Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 57
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The dynamics of economic development determines the need to develop technologies for waste recycling especially the acquisition of condensed fuels for the needs of the local diversification of energy sources. In a short time, Poland will probably lack its own produced electricity. To apply the process of diversification of energy sources, by developing methods of generating energy from waste, it becomes crucial to protect the environment. The use of cogeneration technology based on fuels derived from waste, in particular concentrated oil and gas fuels, is becoming more common and provides the basis for securing the energy supply in the preferred diversification process. Plastic waste processing in the controlled depolymerization process, which is the reverse of the polymerization process for hydrocarbon recovery – uses petroleum derivatives its production. At present, the greatest interest arises in the material recovery of plastics and rubber in the process of anaerobic thermal decomposition (thermolysis/pyrolysis), which is used on an industrial scale and consists in the degradation of polymer bonds into low molecular weight. The imperative of a modern economy is to obtain energy from fuels from waste treatment, including hazardous waste, preferably in the cogeneration process. The fuel obtained from waste may be used to obtain thermal or electric energy in order to diversify energy sources. The article presents innovative Polish technologies of obtaining fuel in processes of anaerobic thermal decomposition mainly of elastomeric and polymeric waste (including hazardous ones) for direct application in power generators of various power.

Go to article

Authors and Affiliations

Artur Gołowicz
Andrzej Wojciechowski
Download PDF Download RIS Download Bibtex

Abstract

In modern conditions of economic globalization, strengthening market relations and aggravated competition, the economic development of an enterprise directly depends on the introduction of innovations. The transition to an innovative path of development requires the enterprise to determine its readiness and assess the possibility of development and the further implementation of innovations. Modern trends in the production of conventional liquid fuels in Ukraine, in particular, analysis of the production of motor gasoline and primary oil refining in Ukraine, the share of motor gasoline produced in Ukraine in the total volume of gasoline used, the volume of bioethanol production by Ukrainian distillery factories have been analyzed in the article. An assessment of the resource production potential for the production of bioethanol in Ukraine has been carried out. Possibilities of bioethanol production in Ukraine at distilleries have been investigated. An analysis of molasses production in Ukraine and theoretically possible volumes of bioethanol production from molasses in Ukraine have been calculated. The scheme of key strategic priorities for the development of the food ethanol and bioethanol in Ukraine has been proposed. The advantages of using bioethanol in the gasoline-ethanol blends for vehicles have been noted, a SWOT analysis map for organizing the production of bioethanol at sugar beet processing plant and distilleries has been generated. The needs of Ukraine in the production of bioethanol have been calculated and, according to the results obtained, the volumes of bioethanol production have been predicted.
Go to article

Authors and Affiliations

Grygorii Kaletnik
1
ORCID: ORCID
Natalia Pryshliak
1
ORCID: ORCID
Yana Palamarenko
1
ORCID: ORCID

  1. Vinnytsia National Agrarian University, Vinnytsia, Ukraine
Download PDF Download RIS Download Bibtex

Abstract

In this work genetic programming is applied to the problem of generating maximum entanglement in multi-qubit systems of different structures. We provide quantum circuits that prepares multipartite entangled states in systems consisting of up to 8 qubits. We present results pertaining to the minimum size of a quantum circuit preparing a maximally entangled multi-qubit state in cases of reduced sets of quantum gates that correspond to spin chain quantum systems.

Go to article

Authors and Affiliations

Przemysław Sadowski
Download PDF Download RIS Download Bibtex

Abstract

The LQR (linear quadratic regulator) control problem subject to singular system constitutes a optimization problem in which one must be find an optimal control that satisfy the singular system and simultaneously to optimize the quadratic objective functional. In this paper we establish a sufficient condition to obtain the optimal control of discounted LQR optimization problem subject to disturbanced singular system where the disturbance is time varying. The considered problem is solved by transforming the discounted LQR control problem subject to disturbanced singular system into the normal LQR control problem. Some available results in literatures of the normal LQR control problem be used to find the sufficient conditions for the existence of the optimal control for discounted LQR control problem subject to disturbanced singular system. The final result of this paper is in the form a method to find the optimal control of discounted LQR optimization problem subject to disturbanced singular system. The result shows that the disturbance is vanish with the passage of time.

Go to article

Authors and Affiliations

Lyra Yulianti
Admi Nazra
Zulakmal
Arifah Bahar
Muhafzan
Download PDF Download RIS Download Bibtex

Abstract

The aim of this study was to investigate the effectiveness of Acceptance and Commitment Therapy (ACT) among parents of children with autism spectrum disorder (ASD) through reducing psychopathology, improving quality of life, and developing psychological skills (psychological flexibility, self-compassion, and ego-resiliency). The study was quasi-experimental in the form of a four-week ACT intervention; three measurements were obtained (baseline, one week after training, one month after training). It involved 60 participants divided into three groups: two criteria groups (ACT in the off-line form, N=20, ACT in the on-line form, N=20), and one control group (N=20). The results showed a significant improvement in the area of quality of life and the level of psychological skills among parents participating in the ACT training, and this improvement was maintained both a week and a month after the end of the training. The form of participation in the training did not differentiate the groups, which may indicate their equivalence. In addition, significant intergroup differences were shown between participants from the criterion groups and those from the control group, as the subjects who did not participate in the training were characterized by lower quality of life and lower level of psychological skills, and higher intensity of psychopathological symptoms. The results can be used both in designing further scientific research and in clinical practice, especially in the psychological care of families of persons diagnosed with ASD, with special focus on the area of developing psychological skills and the use of short-term therapeutic methods.
Go to article

Authors and Affiliations

Anna Pyszkowska
1
Małgorzata Ewa Górnik-Durose
1

  1. University of Silesia, Katowice, Poland
Download PDF Download RIS Download Bibtex

Abstract

There is a growing body of research investigating the relationships among gratitude, self-esteem, and subjective well-being. However, there remains a scarcity of research examining the impact of self-esteem on the relationship between gratitude and subjective well-being within Arabic context. In this study, 300 Arabic speaking adults completed measurements of gratitude, self-esteem, satisfaction with life, and positive and negative experiences. Participants’ ages ranged between 18 and 54 years with a mean age of 29.67 years (SD = 8.91). The correlation results revealed that there were significant positive relationships between gratitude, self-esteem, satisfaction with life, and positive experience, while there were significant negative relationships between gratitude, self-esteem, satisfaction with life, and negative experience. The results also showed that gratitude and self-esteem directly predicted subjective well-being. Additionally, using structural equation modeling, self-esteem exerted a mediation effect on the relationship between gratitude and subjective well-being. The results suggest that enhancing self-esteem could assist adults who have gratitude to experience greater subjective well-being. Using the source of self-esteem, researchers and professionals could improve one’s subjective wellbeing by employing various gratitude activities.

Go to article

Authors and Affiliations

Murat Yildirim
Nouf Abdullah Alshehri
Izaddin Ahmad Aziz
Download PDF Download RIS Download Bibtex

Abstract

The issue of linguistic interference will be analysed from the point of view of medical translations in the Italian-Polish linguistic pair. Since linguistic interference can manifest itself at almost all levels of the text (phonetic, orthographic, morphological, syntactic, socio-cultural), with the analysis of the fragments taken from translated medical documents we would like to understand which are the most frequent cases of the phenomenon when it comes to translated medical texts and which factors favour the interference most.
Go to article

Authors and Affiliations

Katarzyna Maniowska
1

  1. Università Marie Curie-Skłodowska
Download PDF Download RIS Download Bibtex

Abstract

Presently, finding effective, simple, inexpensive, hygienic and safe pest control agents are the biggest challenges in management of stored product insects, where those features are available in most physical factors. The insecticidal efficiency of four diversified physical control agents (ultraviolet and microwave irradiations, thermal remediation and silica nanoparticles) were assayed against the most common coleopteran insect species ( Sitophilus oryzae L. and Tribolium castaneum Herbst) on stored wheat. Exposing tested insects to microwave irradiations (2450 MHz) for 25 sec gave preventive efficiency for stored material, which reached 97.68 and 99.02%, respectively. Sufficient exposure periods to kill 50% of the coleopteran adults (LT50%) were 13 and 14 sec, respectively. For effective control with UV radiations, S. oryzae should be exposed for 12 h and T. castaneum for 24 h. An exposure period of 24 h caused progeny reduction 95.24 and 89.72% and gave preventive efficiency of 94.25 and 93.37%, respectively. Values of LT50% were 56.76 and 74.04 h, respectively. Exposing infested samples of the tested species to 70oC for 10 min killed 100% of adults and caused complete cessation of egg laying. Furthermore, 65°C or 70°C caused full progeny reduction. The lowest level of stored product weight loss (1.15 and 1.35%, respectively) occurred at 70°C, where sufficient exposure temperatures to kill 50% of the coleopteran adults (LTD50%) were 60.95°C and 61.63°C, respectively. Synthetic silica nanoparticles (SSiNPs) were more toxic against the tested populations than bio-silica nanoparticles (BSiNPs) after 48–72 h. A concentration of 1.00 g kg–1 of tested silica nanoparticles caused significant reduction in adult populations, saved wheat grain vitality and gave least lost weights of flour (3.35–6.85%).
Go to article

Authors and Affiliations

Khalil A. Draz
1
Magdy I. Mohamed
2
Reda M. Tabikha
1
Adnan A. Darwish
1
Mohamed A. Abo-Bakr
1

  1. Plant Protection Department, Faculty of Agriculture, Damanhour University, Damanhour, Egypt
  2. Stored Product Pests Department, Plant Protection Research Institute, Agricultural Research Center, Alexandria, Egypt
Download PDF Download RIS Download Bibtex

Abstract

There are significant ruby formations across the world that have been commercialized. In Türkiye there are many mineralogical formation regions with gemological features of high quality. However, there is not enough information in the literature about the formation of ruby in Türkiye, and its usability as a precious stone. In contrast to previous studies, this paper was conducted to reveal the gemological properties of Doğanşehir (Malatya province) rubies and to investigate the usability of polished and cut ruby samples as gemstones. Ruby corundum formations of gemstone quality have recently been discovered in Göksun ophiolites in the Doğanşehir district of Türkiye. These ruby formations take place in greenish and grayish amphibolites in the Göksun ophiolites. The ruby crystals are observed in colors ranging from pink to red and sizes ranging between 2 × 10 mm and 30 × 50 mm. The tectonic position, geological environment, petrographic, mineralogical, geochemical, and gemological characteristics of Doğanşehir crystals indicate that they can be classified as rubies and can be likened to those gems formed in amphibolites in Tanzania. This indicates that Doğanşehir rubies have gemological and mineralogical parameters that are competitive with rubies existing in other places across the world after polishing and cutting. Examples of Doğanşehir rubies prepared by polishing and cutting show that these rubies may feature in the global market in the coming years. Doğanşehir rubies are suitable for COBACORE (community based comprehensive recovery) cutting mostly in large sizes and amounts. Thus, it is a potential gemstone source. Samples prepared by polishing and cutting indicate their suitability as gemstones.
Go to article

Authors and Affiliations

Taşkın Deniz Yıldız
1
ORCID: ORCID
Ni̇hal Deri̇n Coşkun
2
ORCID: ORCID
Veli̇ Uz
3
ORCID: ORCID
Ali̇ İssi̇
3
ORCID: ORCID
Bektaş Uz
4

  1. Adana Alparslan Türkeş Science And Technology University, Department of Mining Engineering, Türkiye
  2. Ordu University, Department of Ceramics and Glass, Türkiye
  3. Dumlupınar University, Department of Materials Science and Engineering, Türkiye
  4. Istanbul Technical University, Department of Geology Engineering, Türkiye
Download PDF Download RIS Download Bibtex

Abstract

The impact of wind power plants on the environmental components is assessed taking into account a number of their parameters, in particular the technical characteristics of wind turbines, the characteristics of networks, engineering and other structures. To do this the life cycle of the wind power plants is described taking into account (by way of inventory) all the necessary materials and resources. Waste management scenarios have been developed, the use of which will make it possible to reduce the harmful impact on the environment. Based on the inventory and input data on the wind farm under study, a diagram is generated – a tree of life cycle processes of the wind power plant – to determine the potential environmental impacts. A list of impact categories that represent the load on the environment caused by the wind power plant is defined; also, the relative contribution of harmful factors is determined for each category, taking into account possible scenarios of waste management. Ecological profiles have been built for all potential impacts on the environment. After normalisation and determination of significance, individual estimates of all indicators and their distribution in three categories of lesions were obtained: human health, ecosystem quality and resources, as well as four stages of the wind farm life cycle: production, dismantling and disposal, operation, transportation and installation. The obtained profiles made it possible to determine individual indicators and eco-indicators, expressed in eco-points that characterise the wind farm under study.
Go to article

Bibliography

BABAK V.P., BABAK S.V., MYSLOVYCH M.V., ZAPOROZHETS A.O., ZVARITCH V.M. 2020. Methods and models for information data analysis. In: Diagnostic systems for energy equipments. Ser. Studies in Systems, Decision and Control. Vol. 281 p. 23–70. Springer. DOI 10.1007/978-3-030-44443-3_2.
BOJKO T.G., PASLAVSKYI M.M., RUDA M.V. 2019. Stability of composite landscape complexes: model formalization. Scientific Bulletin of UNFU. Vol. 29(3) p. 108–113. DOI 10.15421/40290323.
BOSAK N., CHERNIUK V., MATLAI I., BIHUN I. 2019. Studying the mutual interaction of hydraulic characteristics of water distributing pipelines and their spraying devices in the coolers at energy units. Eastern-European Journal of Enterprise Technologies. Vol. 3/8 (99) p. 23–29. DOI 10.15587/1729-4061.2019.166309.
BURTON T., SHARPE D., JENKINS N., BOSSANYI E. 2001. Wind energy. Handbook. Brisbane England. John Wiley & Sons. ISBN 0471489972 pp. 609.
CHAPMAN P.F., ROBERTS F. 1983. Metal resources and energy. Ser. Butterworths Monographs in Materials. Boston. Butterworth- Heinemann Ltd. ISBN 0408108029 pp. 248.
CHERNIUK V.V., IVANIV V.V., BIHUN I.V., WOJTOWICZ JA.M. 2019. Coefficientof flow rate of inlet cylindrical nozzles with lateral orthogonal inflow. In: Lecture Notes in Civil Engineering. Book Series. Vol. 47 [e-book]. Ed. Z. Blikharskyy. Proceedings of CEE p. 50–57.
CHMIELNIAK T. 2008. Technologie energetyczne [Energy technologies]. Warszawa. WNT. ISBN 9788379260324 pp. 564.
CLEARY B., DUFFY A., O’CONNOR A. 2012. Using life cycle assessment to compare wind energy infrastructure. International Symposium on Life Cycle Assessment and Construction. Nantes, France 10– 12.07.2012 p. 87–98.
Danish Energy Agency 2020. Energy Statistics 2020 [online]. [Access 27.05.2020]. Available at: https://ens.dk/en/our-services/statis-tics-data-key-figures-and-energy-maps/annual-and-monthly-sta-tistics
DSTU ISO 14040:2004 2007. Ekologhichne keruvannja. Ocinjuvannja zhyttjevogho cyklu. Pryncypy ta struktura [Environmental management. Life cycle assessment. Principles and structure]. Kyiv. Derzhstandart Ukrajiny.
EU 2010. ILCD Handbook – General guide for Life Cycle Assessment – Detailed guidance. 1st ed. 2010. EUR 24708 EN. Luxembourg. European Commission – Joint Research Centre – Institute for Environment and Sustainability: International Reference Life Cycle Data System Publications Office of the European Union. ISBN 978-92-79-19092-6 pp. 394. DOI 10.2788/38479.
GHENAI CH. 2012. Life cycle analysis of wind turbine. In: Sustainable development, energy, engineering and technologies, manufacturing and environment. Ed. Ch. Ghenai. InTech p. 19–32. DOI 10.5772/29184.
GOEDKOOP M., OELE M., LEIJTING J., PONSIOEN T., MEIJER E. 2016. Introduction to LCA with SimaPro. [online]. [Access 01.08.2012]. Available at: https://www.presustainability.com/download/Sima-Pro8IntroductionToLCA.pdf
ISO 14040 Environmental Management. 1997. Life Cycle Assessment. Principles and framework. International Organisation for standardisation: Geneva, Switzerland. ISO 14042: DSTU ISO/TR 14047:2007 (ISO/TR 14047:2003, IDT) Ekologhichne upravlinnja. Ocinjuvannja vplyviv u procesi zhytt-jevogho cyklu. Pryklady zastosuvannja. [Environmental management. Impact assessment in the life cycle. Application examples], Kyiv. Derzhstandart Ukrajiny.
KOLLNER T., JUNGBLUTH N. 2000. Life cycle impact assessment for land use. Third SETAC World Congress, 21–25.05.2000, Brighton, UK p. 17–35.
LENZEN M., WACHSMANN U. 2004. Wind turbines in Brazil and Germany: An example of geographical variability in life-cycle assessment. Applied Energy. Vol. 77 p. 119–130.
MARTINEZ E., SANZ F., PELLEGRINI S., JIMÉNEZ E., BLANCO J. 2009. Life cycle assessment of a multi-megawatt wind turbine. Renewable Energy. Vol. 34(3) p. 667–673. DOI 10.1016/j.renene.2008.05.020.
POMBO O., ALLACKER K., RIVELA B., NEILA J. 2016. Sustainability assessment of energy saving measures: a multi-criteria approach for residential buildings retrofitting. A case study of the Spanish housing stock. Energy and Buildings. Vol. 116 p. 384–394. DOI 10.1016/j.enbuild.2016.01.019.
PROKOPENKO O., CEBULA J., CHAYEN S., PIMONENKO T. 2007. Wind energy in Israel, Poland and Ukraine: Features and opportunities. International Journal of Ecology and Development. Vol. 32(1) p. 98–107.
SINHA R., LENNARTSSON M., FROSTELL B. 2016. Environmental footprint assessment of building structures: A comparative study. Building and Environment. Vol. 104 p. 162–171. DOI 10.1016/j.buildenv.2016.05.012.
TÓTH T., SZEGEDI S. 2007. Anthropogeomorphologic impacts of onshore and offshore wind farms. Acta Climatologica et Chorologica. Vol. 40–41 p. 147–154.
UN 1992. Climate change and transnational corporations analysis and trends [online]. New York. United Nations. ISBN 92-1-104385-9. [Access 20.06.2006]. Available at: http://www.ieer.org/reports/ climchg/ch7.pdf
VAN DE MEENT D., BAKKER J., KLEPPER O. 1997. Potentially Affected Fraction as an indicator of toxic stress, application of aquatic and terrestrial ecosystems in The Netherlands. 18th Annual Meeting of SETAC, November. San Francisco pp. 245. Vestas 2004. General Specification V90 – 3.0 MW 60 Hz Variable Speed Turbine [online]. [Access 20.05.2006]. Available at: https://report.nat.gov.tw/ReportFront/PageSystem/reportFileDownload/C09503816/002
Vestas 2005. Life cycle assessment of offshore and onshore sited wind power plants based on Vestas V90-3.0 MW turbines [online]. [Access 20.05.2006]. Available at: https://www.vestas.com/content/dam/vestas-com/global/en/sustainability/reports-and-ratings/lcas/LCA_V903MW_version_1_1.pdf.coredownload.inline.pdf
ZBICINSKI I., STAVENUITER J., KOZLOWSKA B., VAN DE COEVERING H. 2006. Product design and life cycle assessment. Ser. Environmental Management. No. 3. Uppsala. The Baltic University Press. ISBN 91-975526-2-3 pp. 314.
Go to article

Authors and Affiliations

Mariia Ruda
1
ORCID: ORCID
Taras Boyko
1
ORCID: ORCID
Oksana Chayka
1
ORCID: ORCID
Maryna Mikhalieva
2
ORCID: ORCID
Olena Holodovska
1
ORCID: ORCID

  1. Lviv Polytechnic National University, 12 Bandera Str., 79000, Lviv, Ukraine
  2. Hetman Petro Sahaidachnyi National Army Academy, Lviv, Ukraine
Download PDF Download RIS Download Bibtex

Abstract

The article reviews selected systems and technological variants of biogas production. Biogas installations and methods of biogas production were characterized in terms of control and measurement. The required technical and technological criteria for biogas production and treatment were indicated. The conditions of biorefining in the context of the generation of new products were analysed. Based on the amount of manure produced in pig production, the potential of biogas production in Poland was indicated based on the visualization of the biogas production potential by poviats in Poland. The substrate in the form of slurry, manure and other agricultural waste for the production of agricultural biogas in Poland was analysed quantitatively. The economic aspects in the agricultural biogas plant sector were revealed, indicating the operation of the economies of scale for this industry sector.
An example of a pilot biogas production for anaerobic digestion using pig slurry is presented. The paper presents pre-liminary results of experimental studies on the course of changes in the biogas volume flow for the average daily production of agricultural biogas and the qualitative composition of agricultural biogas produced from pig slurry. The results of the measurements show a clear influence of the hydrodynamic mixing system of the substrate for the evaluation of the biogas flow through the adhesive bed in the context of agricultural biogas production in the range (1–14) m3 d–1.
Go to article

Authors and Affiliations

Grzegorz Wałowski
1
ORCID: ORCID

  1. Institute of Technology and Life Sciences, Falenty, Department of Renewable Energy, Poznań Branch, ul. Biskupińska 67, 60-463 Poznań, Poland
Download PDF Download RIS Download Bibtex

Abstract

Appropriate agrotechnical measures make it possible to optimise plant cultivation and obtain yields of the highest quality with an appropriate economic production index. The aim of the study was to evaluate different sowing density and row spacing on the morphological and mechanical properties of white lupine ( Lupinus albus L.) seeds. The field experiment was conducted at the Experimental Station for Variety Evaluation in Przecław (50°11'25.2" N, 21°28'55.0" E). The experiment was established at two row spacings (15 cm and 30 cm) and three sowing densities (60, 75, 90 plants per m 2). Mechanical parameters evaluated included destructive force FD (N), relative deformation DR (%) and destructive energy ED (mJ). Seed morphological properties such as weight, length and width were also assessed. Sphericity was also calculated. In the present study, improvements in the mechanical properties of the seeds were obtained by increasing the plant density per unit area of the experiment. In the case of morphological characteristics, only the weight of the analysed lupine seeds changed significantly as a result of row spacing. On the other hand, sowing density did not significantly affect morphological traits. of white lupine seeds. Apart from the spacing and sowing density of plants, the weather conditions in particular years of research were an important factor determining the properties of seeds. Determining the optimum sowing density and row spacing in the field contributes to the optimisation of the production process. Quasi-static mechanical tests are often used to obtain reasonable data on the physical properties of plant materials.
Go to article

Authors and Affiliations

Dagmara Migut
1
ORCID: ORCID
Renata E. Tobiasz-Salach
1
ORCID: ORCID
Barbara Stadnik
1
ORCID: ORCID
Piotr Kuźniar
2
ORCID: ORCID

  1. University of Rzeszow, Department of Crop Production, Zelwerowicz 4 St, Rzeszow, Poland
  2. University of Rzeszow, Department of Food and Agriculture Production Engineering, Rzeszow, Poland
Download PDF Download RIS Download Bibtex

Abstract

The influence of the hold time of the austempering heat treatment at 280°C on the microstructure and corrosion resistance in NaCl-based media of austempered ductile iron was investigated using X-ray diffraction, micro-hardness measurements, corrosion tests and surface observations. Martensite was only found in the sample which was heat treated for a short period (10 minutes). Corrosion tests revealed that this phase does not play any role in the anodic processes. Numerous small pits were observed in the α-phase which is the precursor sites in all samples (whatever the value of the hold time of the austempering heat treatment).

Go to article

Authors and Affiliations

H. Krawiec
V. Vignal
J. Lelito
A. Krystianiak
E. Tyrała
Download PDF Download RIS Download Bibtex

Abstract

There are several springs with the large discharge around the Watuputih Karst Hills area that playing a crucial role in supplying water for both domestic and irrigation needs. The springs are located in the fault and fold zones of the Rembang anticlinorium system. This study was designed to determine the characteristics of karst aquifers from one year of monthly spatio-temporal data on discharge parameters and physico-chemical properties (temperature, pH, EC, Ca2+, Mg2+, HCO3–) of the four major springs, namely Brubulan Tahunan, Sumbersemen, Brubulan Pesucen, and Sendang Sayuran. It used sta-tistical calculations to characterize spring discharge and hydrochemical variations, as well as bivariate correlation analysis and flow-duration curve (FDC). The variability index (Iv), variability (V), and spring coefficient of variation parameters (SCVP) classified Brubulan Tahunan and Sumbersemen as springs producing stable, fairly constant discharge with low variations but characterized Brubulan Pesucen as having unstable, varying discharge with moderate variations. The results showed gently sloping hydrograph, low variations in discharge and hydrochemical properties, a relatively prolonged re-sponse of discharge and CO2-H2O-CaCO3 interaction to rainfall, and slope changes in the FDC. In other terms, although the springs are controlled by faults and folds, they have diffuse groundwater storage system in the form of densely fractured and porous media. These findings also indicate a less developed interconnected conduit, although Brubulan Pesucen is relatively more developed than Sumbersemen and Brubulan Tahunan. The geological structure and hydraulic gradient formed between the groundwater recharge and discharge areas are proven to control the amount of spring discharge actively.

Go to article

Authors and Affiliations

Taat Setiawan
Boy Y.C.S.S. Syah Alam
Eko Haryono
Hendarmawan
Download PDF Download RIS Download Bibtex

Abstract

The aim of the present study was to investigate inline lactate dehydrogenase (LDH) dynamic changes based on different cow factors – different number and stages of lactation, milk yield, and the status of reproduction in clinically healthy dairy cows.

In the Herd Navigator system, LDH activity levels (μmol/min per litre) were measured using dry-stick technology. A total of 378 cows were selected. According to their reproductive status, the cows were classified as belonging to the following groups: Fresh (1 – 44 days after calving); Open (45 – 65 days after calving); Inseminated (1 – 35 days after insemination); Pregnant (35 – 60 days after insemination and pregnant). According to their productivity, the cows were classified into the following groups: <15 kg/day, 15 – 25 kg/day, 25 – 35 kg/day and >35 kg/day. The cows were milked with a DeLaval milking robot (DeLaval Inc. Tumba Sweden) in combination with a Herd Navigator analyser (Lattec I/S. Hillerød Denmark).

In conclusion inline dynamic changes in the milk LDH concentration may increase together with the rise in the lactation period frequency. The highest LDH level determinated in the group of the fresh cows ranged from 5 to 10 DIM, while the highest LDH concentration level was found in the fresh cow milk. Thus, there was a positive relationship between the milk concentration of LDH and the milk yield.

Go to article

Authors and Affiliations

R. Antanaitis
D. Malašauskienė
M. Televičius
V. Juozaitienė
A. Rutkauskas
G. Palubinskas
Download PDF Download RIS Download Bibtex

Abstract

The article presents the results of metallographic and tribological tests on GX120MnCr13 cast steel that was previously subjected to heat treatment (including solution treatment from 1100°C and isothermal holding at 250, 400, and 600°C for 100 hours). The temperatures of the isothermal holding process were selected in order to reflect the possible working conditions of the cast elements that can be made of this cast steel. Wear tests were carried out under dry friction conditions using the ball-on-disc method using a ZrO2 ball as a counter-sample. The tests were carried out with a load of 5 N. The influence of the long-term isothermal holding process on the microstructure of the tested cast steel was analysed by light and scanning microscopy; however, abrasion marks were also examined using a confocal microscope. Based on the tests conducted, it was found that in the microstructures of the sample after solution treatment and samples that were held in isothermal condition at 250 and 400°C, the grain boundary areas were enriched in Mn and Cr compared to the areas inside the grains. Pearlite appeared in the sample that was heated (or held in isothermal holding) at 600°C; its share reached 41.6%. The presence of pearlite in the austenitic matrix increased the hardness to 351.4 HV 10. The hardness of the remaining tested samples was within a range of 221.8–229.1 HV 10. Increasing the hardness of the tested cast steel directly resulted in a reduction in the degree of wear as well as the volume, area, and width of the abrasion marks. A microscopic analysis of the wear marks showed that the dominant process of the abrasive wear of the tested friction pair was the detachment and displacement of the tested material through the indentation as a result of the cyclical impact of the counter-sample.
Go to article

Bibliography

[1] Głownia, J. (2002). Alloy steel castings – application. Kraków: FotoBit. (in Polish).
[2] Maratray, F. (1995). High carbon manganese austenitic steels. Paris: International Manganese Institute.
[3] Krawczyk, J., Matusiewicz, P., Frocisz, Ł., Augustyn-Nadzieja, J., Parzycha, S. (2018). The wear mechanism of mill beaters for coal grinding made-up from high manganese cast. In the 73 WFC, 23-27 September 2018. Kraków, Poland.
[4] Zambrano, O.A., Tressia, G. & Souza, R.M. (2020). Failure analysis of a crossing rail made of Hadfield steel after severe plastic deformation induced by wheel-rail interaction. Engineering Failure Analysis. 115, 1-24. DOI: 10.1016/j.engfailanal.2020.104621.
[5] Wróbel, T., Bartocha, D., Jezierski, J.; Kalandyk, B., Sobula, S., Tęcza, G., Kostrzewa, K., Feliks, E. (2023). High-manganese alloy cast steel in applications for cast elements of railway infrastructure. In the Proceedings of XXIX International Scientific Conference of Polish, Czech and Slovak Foundrymen Współpraca / Spolupráca, 26-28 April 2023. Niepołomice, Poland.
[6] Machado, P.C., Pereira, J.I. & Sinatora, A. (2021). Subsurface microstructural dynamic recrystallization in multiscale abrasive wear. Wear. 486-487, 204111, 1-14. DOI: 10.1016/j.wear.2021.204111.
[7] Tressia, G., Penagos, J.J. & Sinatora, A. (2017). Effect of abrasive particle size on slurry abrasion resistance of austenitic and martensitic steels. Wear. 376-377, 63-69. DOI: 10.1016/j.wear.2017.01.073.
[8] Olawale, J.O., Ibitoye, S.A., Shittu, M.D. & Popoola, A.P.I. (2011). A study of premature failure of crusher jaws. Journal of Failure Analysis and Prevention. 11(6), 705-709. DOI: 10.1007/s11668-011-9511-7.
[9] Stradomski Z., Stachura S., Stradomski G. (2013). Fracture mechanisms in steel castings. Archives of Foundry Engineering. 13, 88-91. DOI: 10.2478/afe-2013-0066.
[10] Martin, M., Raposo, M., Prat, O., Giordana, M.F. & Malarria, J. (2017). Pearlite development in commercial Hadfield steel by means of isothermal reactions. Metallography, Microstructure, and Analysis. 6, 591-597.
[11] Martin, M., Raposo, M., Druker, A., Sobrero, C. & Malarria, J. (2016). Influence of pearlite formation on the ductility response of commercial Hadfield steel. Metallography, Microstructure, and Analysis. 5(6), 505-511. https://doi.org/10.1007/s13632-016-0316-7.
[12] Tęcza, G. & Sobula, S. (2014). Effect of heat treatment on change microstructure of cast high-manganese Hadfield steel with elevated chromium content. Archives of Foundry Engineering. 14, 67-70.
[13] Krawczyk, J., Bembenek, M. & Pawlik, J. (2021). The role of chemical composition of high-manganese cast steels on wear of excavating chain in railway shoulder bed ballast cleaning machine. Materials. 16, 1-16. DOI: 10.3390/ma14247794.
[14] Fedorko, G., Molnár, V., Pribulová, A., Futaš, P., Baricová, D. (2011). The influence of Ni and Cr-content on mechanical properties of Hadfield ́s steel. In the 20th Anniversary International Conference on Metallurgy and Materials – Metal, May 2011 (pp. 18-20). Brno, Czech Republic.
[15] Najafabadi, V., Amini, K. & Alamdarlo, M. (2014). Investigating the effect of titanium addition on the wear resistance of Hadfield steel. Metallurgical Research and Technology. 111(6), 375-382. DOI: 10.1051/metal/2014044.
[16] Tęcza, G. & Garbacz-Klempka, A. (2016). Microstructure of cast high-manganese steel containing titanium. Archives of Foundry Engineering. 16(4), 163-168. DOI: 10.1515/afe-2016-0103.
[17] Kalandyk, B., Tęcza, G., Zapała, R. & Sobula S. (2015). Cast high-manganese steel – the effect of microstructure on abrasive wear behaviour in Miller test. Archives of Foundry Engineering. 15, 35-38. DOI: 10.1515/afe-2015-0033.
[18] Shan, Q., Ge, R., Li Z., Zhou, Z., Jiang ,Y., Lee, Y.-S. & Wu, H. (2021). Wear properties of high-manganese steel strengthened with nano-sized V2C precipitates. Wear. 482-483, 203922, 1-10. DOI: 10.1016/j.wear.2021.203922.
[19] Ayadi, S. & Hadji, A. (2021). Effect of chemical composition and heat treatments on the microstructure and wear behavior of manganese steel. International Journal of Metalcasting. 15(2), 510-519. DOI: 10.1007/s40962-020-00479-2.
[20] Gürol, U. & Can Kurnaz, S. (2020). Effect of carbon and manganese content on the microstructure and mechanical properties of high manganese austenitic steel. Journal of Mining and Metallurgy Section B - Metallurgy. 56, 171-182. DOI: 10.2298/JMMB191111009G.
[21] Kalandyk, B., Zapała, R., Kasińska, J. & Madej, M. (2021) Evaluation of microstructure and tribological properties of GX120Mn13 and GX120MnCr18-2 cast steels. Archives of Foundry Engineering. 21(3), 67-76. DOI: 10.24425/afe.2021.138681.
[22] Atabaki, M.M., Lafaril, S. & Abdollah-Pour, H. (2012) Abrasive wear behavior of high chromium cast iron and Hadfield steel-A comparison. Journal of Iron and Steel Research, International. 19, 43-50. DOI: 10.1016/S1006-706X(12)60086-7.
[23] Gierek, A. (2005). Zużycie tribologiczne. Gliwice: Wyd. Politechniki Śląskiej.
[24] Kalandyk, B., Zapała, R., Madej, M., Kasińska, J. & Piotrowska, K. (2022). Influence of pre-hardened GX120Mn13 cast steel on the tribological properties under technically dry friction. Tribologia. 3, 17-24. DOI: 10.5604/01.3001.0016.1020.
[25] El-Fawkhry, M.K., Fathy, A.M., Eissa, M.M. & El-Faramway, H. (2014). Eliminating heat treatment of Hadfield steel in stress abrasion wear applications, International Journal of Metalcasting. 8, 29-36. DOI: 10.1007/BF03355569.
[26] Cybo, J., Jura, S. (1995). Functional description of isometric structures in quantitative metallography. Functional description of isometric structures in quantitative metallography. Gliwice: Wyd. Politechniki Śląskiej. (in Polish).
[27] Standard EN 10349: 2009. Cast steel castings - Castings made of manganese austenitic cast steel. (in Polish).
[28] Standards PN-EN ISO 6507-1: 2007. Metallic materials - Vickers hardness test.
[29] Standards ISO 20808: 2016. Fine ceramics (advanced ceramics, advanced technical ceramics) - Determination of friction and wear characteristics of monolithic ceramics by ball-on-disc method. [30] Mishra, S. & Dalai R. (2021). A comparative study on the different heat-treatment techniques applied to high manganese steel. Materials Today: Proceedings. 44(1), 2517-2520. DOI: 10.1016/j.matpr.2020.12.602.
[31] Kawalec, M. & Fraś, E. (2009). Effect of silicon on the structure and mechanical properties of high-vanadium cast iron. Archives of Foundry Engineering. 9(3), 231-234.
[32] Dziubek, M., Rutkowska-Gorczyca, M., Dudziński, W. & Grygier, D. (2022). Investigation into changes of microstructure and abrasive wear resistance occurring in high manganese steel X120Mn12 during isothermal annealing and re-austenitisation process. Materials. 15(7), 2622. DOI: 10.3390/ma15072622.
[33] El Fawkhry M. K. (2021). Modified Hadfield steel for castings of high and low gouging applications. International Journal of Metalcasting. 15(4), 613-624. DOI: 10.1007/s40962-020-00492-5.
[34] Lindroos, M., Apostol, M., Heino, V., Valtonen, K., Laukkanen, A., Holmberg, K. & Kuokkala, V.T. (2015). The deformation, strain hardening, and wear behavior of chromium-alloyed Hadfield steel in abrasive and impact conditions. Tribology Letters. 57, 1-11. DOI: 10.1007/s11249-015-0477-6.
[35] Luo, Q. & Zhu, J. (2022). Wear property and wear mechanisms of high-manganese austenitic Hadfield steel in dry reciprocal sliding. Lubricants. 10(3), 1-18. DOI: /10.3390/lubricants10030037.
Go to article

Authors and Affiliations

Barbara Kalandyk
1
ORCID: ORCID
Renata E. Zapała
1
ORCID: ORCID
Iwona Sulima
2
ORCID: ORCID
Piotr Furmańczyk
3
ORCID: ORCID
Justyna Kasińska
3
ORCID: ORCID

  1. AGH University of Krakow, Faculty of Foundry Engineering, al. A. Mickiewicza 30, 30-059 Krakow, Poland
  2. University of the National Education Commission Krakow, Institute of Technology, ul. Podchorążych 2, 32-084 Krakow, Poland
  3. Kielce University of Technology, Faculty of Mechatronics and Mechanical Engineering, Poland
Download PDF Download RIS Download Bibtex

Abstract

In the Middle Ages, tens of thousands types of uni-faced bracteate coins were struck in the period 1140−1520. The existence of hundreds of small independent currency areas with their own mints in central, eastern, and northern Europe and the strong link between bracteates and periodic re-coinage explain the large number of bracteate types. The classification and dating of coins can provide insight into economic and monetary development when studying coin hoards and cumulative finds. A central problem when classifying bracteates is that most of them are anonymous, i.e., there are seldom any legends or letters. However, bracteates struck in closely located mints almost always have the same regional monetary standard. In this study, I show how monetary standards in combination with social attributes can be used to classify bracteates when both legends and find information are lacking. I also provide an economic explanation why closely related mints voluntary joined a specific monetary standard.
Go to article

Authors and Affiliations

Roger Svensson
1
ORCID: ORCID

  1. The Research Institute of Industrial Economics (IFN) P.O. Box 55665, SE–10215 Stockholm, Sweden
Download PDF Download RIS Download Bibtex

Abstract

The paper presents special forms of an ensemble of classifiers for analysis of medical images based on application of deep learning. The study analyzes different structures of convolutional neural networks applied in the recognition of two types of medical images: dermoscopic images for melanoma and mammograms for breast cancer. Two approaches to ensemble creation are proposed. In the first approach, the images are processed by a convolutional neural network and the flattened vector of image descriptors is subjected to feature selection by applying different selection methods. As a result, different sets of a limited number of diagnostic features are generated. In the next stage, these sets of features represent input attributes for the classical classifiers: support vector machine, a random forest of decision trees, and softmax. By combining different selection methods with these classifiers an ensemble classification system is created and integrated by majority voting. In the second approach, different structures of convolutional neural networks are directly applied as the members of the ensemble. The efficiency of the proposed classification systems is investigated and compared to medical data representing dermoscopic images of melanoma and breast cancer mammogram images. Thanks to fusion of the results of many classifiers forming an ensemble, accuracy and all other quality measures have been significantly increased for both types of medical images.
Go to article

Authors and Affiliations

Fabian Gil
1
Stanisław Osowski
1 2
Bartosz Świderski
3
Monika Słowińska
4

  1. Military University of Technology, Faculty of Electronics, Institute of Electronic Systems, ul. gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland
  2. Warsaw University of Technology, Faculty of Electrical Engineering, pl. Politechniki 1, 00-661 Warsaw, Poland
  3. University of Life Sciences, ul. Nowoursynowska 166, 02-787 Warsaw
  4. Central Clinical Hospital Ministry of Defense, Military Institute of Medicine – National Research Institute, ul. Szaserów 128, 04-141 Warsaw, Poland
Download PDF Download RIS Download Bibtex

Abstract

The objective of this study was to review the current knowledge based on in vitro and in vivo studies, that evaluated the enamel damage connected with removal of metal and ceramic orthodontic brackets taking into account different debonding methods. Brackets fracture was also assessed. The protocol for this study was constructed according to the PRISMA statement. The literature review was performed in MEDLINE via PubMed, Cochrane and Scopus databases in May 2021. The searching was repeated in Journal of Stomatology, Orthodontic Forum and grey literature was screened using Google Scholar. Out of eligible studies 207 were screened by title and abstract, 85 subjected to full-text analysis and 30 were qualified for the research. The prevalence of enamel fracture ranged from 0 to 94.4%. The results of our review do not allow to identify the manual method of debonding that minimizes the risk of enamel damage. Thermal method and laser irradiation reduce the risk of enamel fracture.
Go to article

Authors and Affiliations

Marta Gibas-Stanek
1
Piotr Pełka
2
Małgorzata Pihut
1

  1. Department of Prosthodontics and Orthodontics, Dental Institute, Jagiellonian University Medical College, Kraków, Poland
  2. 5th Military Clinical Hospital with Policlinic, Orthodontic Clinic, Kraków, Poland
Download PDF Download RIS Download Bibtex

Abstract

Efficiency of agitation was considered for different physical systems on the basis of our own experimental studies on homogenisation, heat and mass transfer as well as gas hold-up. Measurements were performed for different physical systems: Newtonian liquids of low and higher viscosity, pseudoplastic liquid, gas–liquid and gas–solid–liquid systems agitated in vessels of the working volume from 0.02 m3 to 0.2 m3. Agitated vessels of different design were equipped with a high-speed impeller (10 impellers were tested). Comparative analysis of the experimental results proved that energy inputs (power consumption) should be taken into account as a very important factor when agitation efficiency is evaluated in order to select a proper type of equipment. When this factor is neglected in the analysis, intensification of the process can be estimated only.
Go to article

Bibliography

Busciglio A., Opletal M., Moucha T., Montante G., Paglianti A., 2017. Measurement of gas hold-up distribution in stirred vessels equipped with pitched blade turbines by means of Electrical Resistance Tomography. Chem. Eng. Trans., 57, 1273–1278. DOI: 10.3303/CET1757213.

Cudak M., 2016. Experimental and numerical analysis of transfer processes in a biophase–gas–liquid system in a bioreactor with an impeller (in Polish). BEL Studio Sp. z o.o., Warszawa.

Cudak M., 2020. The effect of vessel scale on gas hold-up in gas–liquid systems. Chem. Process Eng., 41, 4, 241–256. DOI: 10.1515/cpe-2016-0005.

Cudak M., Galego Zarosa R., Lopez Vazquez I., Karcz J., 2019. An effect of different factors on the production of mechanically agitated multiphase biophase–gas–liquid systems. Chem. Eng. Trans., 74, 1021–1026. DOI: 10.3303/CET1974171.

Cudak M., Kiełbus-R˛apała A., Major-Godlewska M., Karcz J., 2016. Influence of different factors on momentum transfer in mechanically agitated multiphase systems. Chem. Process Eng., 37, 41–53. DOI: 10.1515/cpe-2016-0005.

Harnby N., Edwards M.F., Nienow A.W., 1997. Mixing in the process industries. Butterworth Co Ltd, London.

Kamienski J., 2004. Agitation of multiphase systems (in Polish), WNT, Warszawa.

Karcz J., Cudak M., 2002. Efficiency of the heat transfer process in a jacketed agitated vessel equipped with an eccentrically located impeller. Chem. Pap., 56, 6, 382–386.

Karcz J., Cudak M., Szoplik J., 2005. Stirring of a liquid in a stirred tank with an eccentrically located impeller. Chem. Eng. Sci., 60, 2369–2380. DOI: 10.1016/j.ces.2004.11.018.

Karcz J., Major M., 2001. Experimental studies of heat transfer in an agitated vessel equipped with vertical tubular coil (in Polish). Inz. Chem. i Proc., 22, 445–459.

Kiełbus-Rąpała A., 2006. The studies of transfer processes in a mechanically agitated three-phase liquid–gas–solid system (in Polish). PhD thesis, Technical University of Szczecin, Szczecin.

Kiełbus-Rąpała A., Karcz J., 2009. Influence of suspended solid particles on gas–liquid mass transfer coefficient in a system stirred by double impellers. Chem. Pap., 63, 2, 188–196. DOI: 10.2478/s11696-009-0013-y.

Kiełbus-Rąpała A., Rapisarda A., Karcz J., 2019. Experimental analysis of conditions of gas–liquid–floating particles system production in an agitated vessel equipped with two impellers. Chem. Eng. Trans., 74, 1027–1032. DOI: 10.3303/CET1974172.

Kracik T., Petricek R., Moucha T., 2020. Mass transfer in coalescent batch fermenters with mechanical agitation. Chem. Eng. Res. Des., 160, 587–592. DOI: 10.1016/j.cherd.2020.03.015.

Kuncewicz Cz., 2012. Mixing of high viscosity liquids: Process principles (in Polish). Łódz University of Technology, Łódz.

Lee B.W., Dudukovic M.P., 2014. Determination of flow regime and gas hold-up in gas–liquid stirred tanks. Chem. Eng. Sci., 109, 264–275. DOI: 10.1016/j.ces.2014.01.032.

Littlejohns J.V., Daugulis A.J., 2007. Oxygen transfer in a gas–liquid system containing solids of varying oxygen affinity. Chem. Eng. J., 129, 67–74. DOI: 10.1016/j.cej.2006.11.002.

Major-Godlewska M., Karcz J., 2018. Power consumption for an agitated vessel equipped with pitched blade turbine and short baffles. Chem. Pap., 72, 1081–1088. DOI: 10.1007/s11696-017-0346-x.

Michalska M., 2001. Heat transfer in a stirred tank equipped with the vertical tubular coil and rotating agitator (in Polish). PhD thesis, Technical University of Szczecin, Szczecin.

Nagata S., 1975. Mixing. Principles and applications, Kodansha Ltd. Tokyo. Novak V., Rieger F., 1994. Mixing in unbaffled vessel. 8th European Conference on Mixing, Cambridge, 21– 23.09.1994, ICHEME Symposium Series, 136, 511–518.

Oldshue J.Y., 1983. Fluid mixing technology. McGraw-Hill, New York.

Ozkan O., Calimli A., Berber R., Oguz H., 2000. Effect on inert solid particles at low concentrations on gas–liquid mass transfer in mechanically agitated reactors. Chem. Eng. Sci., 55, 2737–2740. DOI: 10.1016/S0009-2509(99)00532-1.

Paul E.L., Atiemo-Obeng V.A., Kresta S.M., 2004. Handbook of industrial mixing: Science and Practice. Wiley.

Petera K., Dostal M., Verisova M., Jirout T., 2017. Heat transfer at the bottom of a cylindrical vessel impinged by a swirling flow from an impeller in a draft tube. Chem. Biochem. Eng. Q., 31, 343–352. DOI: 10.15255/CABEQ.2016.1057.

Petricek R., Moucha T., Rejl F.J., Valenz L., Haidl J., Cmelikova T., 2018. Volumetric mass transfer coefficient, power input and gas hold-up in viscous liquid in mechanically agitated fermenters. Measurements and scale-up. Int. J. Heat Mass Transf., 124, 1117–1135. DOI: 10.1016/j.ijheatmasstransfer.2018.04.045.

Rosa V.S., Torneiros D.L.M., Maranhão H.W.A., Moraes M.S., Taqueda M.E.S., Paiva J.L., de Moraes Júnior D., 2020. Heat transfer and power consumption of Newtonian and non-Newtonian liquids in stirred tanks with vertical tube baffles. Appl. Therm. Eng., 176, 115355, 1–24. DOI: 10.1016/j.applthermaleng.2020.115355.

Stręk F., 1981. Agitation and agitated vessels (in Polish). WNT, Warszawa.

Szoplik J., 2004. The studies of the mixing time in a stirred tank with an eccentrically located impeller (in Polish). PhD thesis, Technical University of Szczecin, Szczecin.

Szoplik J., Karcz J., 2005. An efficiency of the liquid homogenization in agitated vessels equipped with off-centred impeller. Chem. Pap., 59, 6a, 373–379.

Tatterson G.B., 1991. Fluid mixing and gas dispersion in agitated tanks. McGraw Hill Inc, Tokyo.

Zwietering T.N., 1958. Suspending of solids particles in liquid by agitation. Chem. Eng. Sci., 8, 244–253. DOI: 10.1016/0009-2509(58)85031-9.
Go to article

Authors and Affiliations

Joanna Karcz
1
Jolanta Szoplik
1
ORCID: ORCID
Marta Major-Godlewska
1
Magdalena Cudak
1
Anna Kiełbus-Rapała
1

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, al. Piastów 42, 71-065 Szczecin, Poland
Download PDF Download RIS Download Bibtex

Abstract

The road network development programme, as well as planning and design of transport systems of cities and agglomerations require complex analyses and traffic forecasts. It particularly applies to higher-class roads (motorways and expressways), which in urban areas, support different types of traffic. Usually there is a conflict between the needs of long-distance traffic, in the interest of which higher-class roads run through undeveloped areas, and the needs of bringing such road closer to potential destinations, cities [1]. By recognising the importance of this problem it is necessary to develop the research and methodology of traffic analysis, especially trip models. The current experience shows that agglomeration models are usually simplified in comparison to large city models, what results from misunderstanding of the significance of these movements for the entire model functioning, or the lack of input data. The article presents the INMOP 3 research project results, within the framework of which it was attempted to increase the accuracy of traffic generation in agglomeration model owing to the use of BigData – the mobile operator’s data on SIM card movements in the Warsaw agglomeration.

Go to article

Authors and Affiliations

A. Brzeziński
T. Dybicz
Ł. Szymański
Download PDF Download RIS Download Bibtex

Abstract

In this paper, the problem of deformation induced by an open pit excavation in anisotropic stiff soils is analysed by FE modelling. The presented research is focused on the influence of material model with anisotropic stiffness on the accuracy of deformation predictions as compared with the field measurements. A new hyperelastic-plastic model is applied to simulate anisotropic mechanical behaviour of stiff soils. It is capable to reproduce mixed variable stress-induced anisotropy and constant inherent cross-anisotropy of the small strain stiffness. The degradation of stiffness depending on strain is modelled with the Brick-type model. The model formulation and parameters are briefly presented. General deformation pattern obtained in the exemplary 2D boundary value problem of an open pit excavation is investigated considering different values of inherent cross-anisotropy coefficient of small strain stiffness. The numerical simulations are performed as a coupled deformation-flow analysis which allows to properly model the drainage conditions. The excavation phases are simulated by removal of soil layers according to the realistic time schedule. Finally, the monitored case of the trial open pit excavation in heavily overconsolidated Oxford Clay at Elstow, UK is simulated with proposed material model both in 2D and 3D conditions. The obtained calculation results are compared with displacement measurements and discussed.
Go to article

Authors and Affiliations

Katarzyna Lisewska
1
ORCID: ORCID
Marcin Cudny
1
ORCID: ORCID

  1. Gdansk University of Technology, Faculty of Civil and Environmental Engineering, ul. Gabriela Narutowicza 11/12, 80-233 Gdansk, Poland

This page uses 'cookies'. Learn more