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Number of results: 8
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Effectiveness of "Enhanced Coagulation" in Low Mineralization Water Treatment

Jolanta Gumińska
Archives of Environmental Protection | 2005 | vol. 31 | No 3 | 109-115
Keywords soft water organic compounds enhanced coagulation trihalomcthans
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Abstract

During the process of ,,enhanced coagulation" except for colloids and suspensions removal, the removal of associated organic compounds including DPD (Disinfection By-Products) precursors is crucial. It is often necessary to decrease color and turbidity of treated water to values which arc significantly lower than accepted for drinking water. On the basis of presented results of the research it was found out that under strict technological conditions coagulation of low mineralization waters ensures effective treatment, including significant THMs precursors removal, even when water is of low temperature. However, it is necessary to apply two different methods of coagulation (volumetric coagulation and direct filtration) dependently of water temperature with the usage of the same equipment (a flocculation chamber, a vertical sedimentation tank and a pressure rapid filter) including the same point of a coagulant dosing. During the periods of ,,high temperature" the treatment should be based on volumetric coagulation and during the periods of ,,low temperature" of water direct filtration should be applied.
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Authors and Affiliations

Jolanta Gumińska

Review of impacts of climate changes on the urban water security of Islamabad, Pakistan

Attaullah Shah Rehmat Karim Karamat Ali
Journal of Water and Land Development | 2022 | No 54 | 109-115 | DOI: 10.24425/jwld.2022.141561
Keywords climate change global warming Islamabad urban water
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Abstract

The global warming and subsequent climate change has seriously threatened the glaciers of the Hindukush Karakoram Himalaya (HKH) region. These glaciers provide water to more than 60% people of the 11 countries, including Pakistan. The capital city of Pakistan has witnessed unprecedented urbanisation, population increase, development of new townships and associated economic activities. These challenges, together with climate change, have created severe pressure on the water resources of the city. In this mixed mode research, including questionnaire survey of 20 questions was distributed among the residents of the city online through Google Form. The questions were related to the expected impact of climate change on the availability of water, measures for conservation of water etc. About 205 residents from various parts of the city with different demographic backgrounds responded. This was followed by Focus Group Discussions (FDGs) of the experts and the major challenges to the urban water security of Islamabad with special reference to climate change have been assessed. The research has revealed that the water resources of the city are highly unsustainable. The residents have high concerns about the availability and quality of water. The results have shown that there is a number of governance issues in water distribution systems of the city. There are no organized water conservation strategies employed by City Government. The lack of institutional and policy framework has further complicated the situation. Residents seem willing for metering of water for its conservation. Recommendations have been made to municipal authorities for rational water resource management of the city.
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Authors and Affiliations

Attaullah Shah
1
Rehmat Karim
2
Karamat Ali
3
  1. Karakorum International University, Department of Civil Engineering Technology, University Road, Gilgit, 15100, Baltistan, Pakistan
  2. Karakorum International University, Department of Tourism and Hospitality Management, Gilgit, Baltistan, Pakistan
  3. Karakorum International University, Department of Environmental Sciences, Gilgit, Baltistan, Pakistan

Evaluation of Wear Mechanisms of Graphites Used for Crystallisers for Continuous Casting

A. Brudny J. Kulasa B. Juszczyk J. Myalski S. Roskosz R. Wycisk P. Kwaśniewski P. Strzępek M. Poręba
Archives of Foundry Engineering | 2022 | vol. 22 | No 4 | 109-115 | DOI: 10.24425/afe.2022.143958
Keywords Innovative foundry technologies and materials Wear resistance Graphite Crystalliser Tribology
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Abstract

This paper presents the results of research concerning the evaluation of tribological properties of graphite materials used, among others, for crystallisers for continuous casting of non-ferrous metals and their alloys. Graphite materials differing not only in their physical properties but also in the technology of their production were selected from a wide range of commercially available products. Wear resistance investigations of the tested graphite materials were carried out on a pin-on-disc tribometer under technically dry friction conditions on a sliding distance of 1000 m. A constant load but variable speed was used in the tests. The mean value of the coefficient of friction and the wear of the material were determined based on the tribological tests carried out. It was observed that as the speed increases, the average value of the coefficient of friction decreases, while the wear increases. A microstructural analysis of the wear track showed that the friction mechanism depends mainly on the graphite formation technology, which is related to the microstructure of the tested materials, and to a lesser extent to their physical and mechanical properties. Varying the speed values made it possible to trace changes in the wear mechanism, on the basis of which it is possible to predict the durability and reliability of graphite crystalliser operation.
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Bibliography

[1] Kwaśniewski, P., Strzępek, P., Kiesiewicz, G., Kordaszewski, Sz., Franczak, K., Sadzikowski, M., Ściężor, W., Brudny, A., Kulasa, J., Juszczyk, B., Wycisk, R. & Śliwka, M. (2021). External surface quality of the graphite crystallizer as a factor influencing the temperature of the continuous casting process of ETP grade copper. Materials. 14(21), 6309, 1-14. DOI: 10.3390/ma14216309.
[2] Brudny, A., Kulasa, J., Cwolek, B., Malec, W. & Juszczyk, B. (2022). Influence of the continuous casting process of tin-zinc-lead bronze on the wear of the graphitecrystallizer. Metalurgija. 61(3-4), 785-788. ISSN 0543-5846.
[3] Lee, S.-M., Kang, D.-S. & Roh, J.-S. (2015). Bulk graphite: materials and manufacturing process. Carbon Letters. 16(3), 135-146. DOI: 10.5714/CL.2015.16.3.135.
[4] Özmen, Y. (2015). Tribological behavior of carbon-based materials. In ASME 2015 International Mechanical Engineering Congress and Exposition, 12-19 November (pp. 13-19). Houston, Texas, USA. DOI: 10.1115/IMECE2015-50233.
[5] Erdemir, A. & Donnet, C. (2006). Tribology of diamond-like carbon films: recent progress and future prospects. Journal of Physics D Applied Physics. 39(18), 311-327. DOI: 10.1088/0022-3727/39/18/R01.
[6] Alisin, V. & Roshchin, M.N. (2019). Tribology of carbon-containing materials at high temperatures. Journal of Physics Conference Series. 1399(4), 044034, 1-6. DOI: 10.1088/1742-6596/1399/4/044034.
[7] Zhai, W., Srikanth, N., Kong, L.B. & Zhou, K. (2017). Carbon nanomaterials in tribology. Carbon. 119, 150-171. DOI: 10.1016/j.carbon.2017.04.027.
[8] Grill, A. (1993). Review of the tribology of diamond-like carbon. Wear. 168(1-2), 143-153. DOI: 10.1016/0043-1648(93)90210-D.
[9] Szeluga, U., Pusz, S., Kumanek, B., Myalski, J. Hekner, B., Tsyntsarski, B., Oliwa, R. & Trzebicka, B. (2018). Carbon foam based on epoxy/novolac precursor as porous micro-filler of epoxy composites. 105, 28-39. DOI: 10.1016/j.compositesa.2017.11.004.
[10] Szeluga, U., Olszowska, K., Pusz, S., Myalski, J., Godzierz, M., Kobyliukh, A. & Tsyntsarski, B. (2021) Effect of grain fractions of crushed carbon foam on morphology and thermomechanical and tribological properties of random epoxy-carbon composites. Wear. 466-467, 1-14. DOI: 10.1016/j.wear.2020.203558.
[11] SGL Carbon. (2022). SGL Carbon. Retrieved March 2022 from https://www.sglcarbon.com/
[12] Robertson, J.F.R. (2002). Diamond-like amorphous carbon. Materials Science and Engineering Reports. 37(4-6), 129-281. DOI: 10.1016/S0927-796X(02)00005-0.
[13] Pérez-Mayoral, E., Matos, I., Bernardo, M. & Fonesca, I.M. (2019). New and advanced porous carbon materials in fine chemical synthesis. Emerging precursors of porous carbons. Catalysts. 9 (2), 133, 1-35. DOI: 10.3390/catal9020133.
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Authors and Affiliations

A. Brudny
1
ORCID: ORCID
J. Kulasa
1
ORCID: ORCID
B. Juszczyk
1
ORCID: ORCID
J. Myalski
2
ORCID: ORCID
S. Roskosz
2
ORCID: ORCID
R. Wycisk
3
P. Kwaśniewski
4
ORCID: ORCID
P. Strzępek
4
ORCID: ORCID
M. Poręba
5
ORCID: ORCID
  1. Łukasiewicz Research Network - Institute of Non-Ferrous Metals, Poland
  2. Silesian University of Technology, Faculty of Materials Engineering, Poland
  3. Carbo-Graf Sp. z o.o., Poland
  4. AGH University of Science and Technology, Department of Non-Ferrous Metals, Poland
  5. Rzeszów University of Technology, The Faculty of Mechanical Engineering and Aeronautics, Poland

Autologous activated platelet-rich plasma (PRP) in bone tissue healing – does it work? Assessment of PRP effect on bone defect healing in animal models

S. Skwarcz I. Bryzek A. Gregosiewicz E. Warda K. Gawęda M. Tarczyńska R. Węgłowski J. Skwarcz R. Nadulski A. Starek J. Sanford
Polish Journal of Veterinary Sciences | 2019 | vol.22 | No 1 | 109-115 | DOI: 10.24425/pjvs.2019.127077
Keywords platelet-rich plasma bone regeneration bone defects rabbit model
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Abstract

Introduction: Platelet-rich plasma (PRP) preparations can be used in bone tissue healing but there are numerous doubts among clinical orthopedists about effectiveness of this method.

Materials and methods: The studies were carried out in 12 rabbits of white termond breed. In operating room we operationally generated cylindrical, unicortical defects of the diameter of 4 mm in the middle of the shafts of both femurs. The defects in the left bones were left without filling and served as controls, and 0.7 ml of the ready-to-use PRP was administered to the defects in the right bones (experimental group). We evaluated the usefulness of the diagnostic methods applied: biomechanical tests, micro-CT tests, densitometry, typical radiology, macroscopic measurements, histopathological examinations.

Results: The macroscopic measurements showed a statistically significant increase in the dimension in the area of the right defect filled with PRP in relation to the control group. In experimented group, the assessment of the X-ray images showed the formation of a callus cuff around the defects. Densitometric examinations showed no statistically significant differences between defects in the experimental and control group. The analysis of the micro-CT examina- tions showed an increase in the total volume of the tissue examined (Vb) and the low density tissue fraction (Vb2) in the experimental group. The biomechanical examinations revealed signi- ficant decrease in the maximum breaking force (F max) necessary to break the bone in the experi- mental group in relation to the control group.

Conclusions: Platelet-rich plasma (PRP) stimulates bone formation in the area of bone defects and may accelerate bone regeneration.

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Authors and Affiliations

S. Skwarcz
I. Bryzek
A. Gregosiewicz
E. Warda
K. Gawęda
M. Tarczyńska
R. Węgłowski
J. Skwarcz
R. Nadulski
A. Starek
J. Sanford

Technical Notes. Earmuff Noise Leakage Measurements and Evaluation

Samir N.Y. Gerges Rafael N.C. Gerges Roberto A. Dias
Archives of Acoustics | 2015 | vol. 40 | No 1 | 109-115 | DOI: 10.1515/aoa-2015-0013
Keywords earmuffs
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Abstract

This paper reports the quantitative effect of leakage on the noise attenuation of earmuff hearing protectors. The technology used in this study to measure the noise leakage is considered to be a new contribution to this topic. An array of sensors placed between an earmuff and a dummy human head or flat surface was used to measure the contact area. Areas of no contact are considered as the leakage elements. Eight earmuffs varying from high quality/high cost to low quality/low cost were tested, the leakage areas were measured and the reduction in the noise attenuation due to leakage was calculated
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Authors and Affiliations

Samir N.Y. Gerges
Rafael N.C. Gerges
Roberto A. Dias

The Protection of Maritime Activity in Times of Crisis and War

Andrzej Makowski Dariusz Bugajski
Prawo Morskie | 2001 | No XVI | 109-115
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Abstract

The article presents the principles and the organization of supervision and protection of seagoing activities that are applied and enforced by the navies ofNATO member states. Assuming that the most likely kind of conflict in the future will be a regional conflict, characterized by limited range and a fluctuating level of danger, and also by a continuation of commercial maritime activity, NATO has developed appropriate procedures in the area of supervision and protection ofmaritime activity, both during the conflict and in a time of crisis (and of growing crisis). This article discusses contemporary views relating to supervision and protection of maritime activity. It presents the regional system of supervision and protection of maritime activity, its detailed organization, and the principles of its operation. It presents - for the first time in a Polish publication - the issue of supervision and protection of maritime activity developed by NATO.
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Authors and Affiliations

Andrzej Makowski
ORCID: ORCID
Dariusz Bugajski

History-Historiography- Ideology ( Reflections on Zarys historii historiografii polskiej by Andrzej F. Grabski)

Ewa Domańska
Historyka Studia Metodologiczne | 2001 | vol. 31 | 109-115
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Abstract

In this analysis of 'Zarys historii historiografii polskiej ('An Outline History of Polish Historiography') by Andrzej F. Grabski, the Author stresses the ideological dimensions of historiography and the relation between historical knowledge and political power. If modem academic history can be viewed as the ideological support of the nation-state, then the study of Polish historiography can serve as a useful introduction to the history of Poland itself. This is so, because the history of the nation cannot be separated from the different representations of it.
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Authors and Affiliations

Ewa Domańska
ORCID: ORCID

Reviews

Wiadomości Numizmatyczne | 2005 | Rok XLIX | Zeszyt 1 (179) | 109-115
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