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Number of results: 10
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Abstract

The paper presents the way of water quality improvement in storage reservoirs, using pre-dams with plant filters. Pre-dams, built above the main reservoirs, reduce the inflow of pollutants transported by the river and take over most of biochemical processes responsible for eutrophication of the stored water. As a result, water flowing to the main reservoir contains smaller loads of pollutants. The above-mentioned method is more economic, requires relatively short construction time and is less laborious than generally used methods of surface water protection. It is specially recommended to improve the quality of water in small reservoirs, where quick silting and eutrophication occur. Proper functioning of pre-dams depends on proper selection of their parameters, such as: water storage time, water flow velocity, filling depth and type of plant filters. The authors estimated the effectiveness of a pre-dam reservoir situated above the main reservoir in Mściwojów on the Wierzbiak River. The pre-dam reservoir consists of a three-chamber sediment tank and three chambers with plant barriers. The purpose of the chambers is to decrease the quantity of sediments, the biogenie substances and other pollutants carried with water flowing to the main reservoir. Research carried out during the period 2000-2001 showed that pre-dams significantly contributed to the improvement of the water quality in the main reservoir - nitrates were eliminated in ca 65% and phosphates in ca 52%.
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Authors and Affiliations

Włodzimierz Czamara
Alicja Czamara
Mirosław Wiatkowski
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Abstract

The article deals with the state of utilization and protection of the water· resources in the Mokaśnica river basin (MRB) within the larger Mostarsko Biało catchment area (MRB). The authors present data on the Mostarsko Blato basin, provided through the analyses of the results of earlier research projects dealing with surface and groundwater flows, particularly related to the research carried out in the MR fl. The previous water engineering works in the MRB have been analyzed for effects on the natural environment and the influence of such works on the regime of surface flow and groundwater aquifer geometry. In order to protect the area of the MRB from further devastation, the authors suggest some protective measures and due improvements. A special environmental protection study is necessary lor heller management otthe MRB waters and the natural environrncnt, including the analysis ofthe possibility of losing said water resources due to the implemented engineering interventions.
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Authors and Affiliations

Bozo Soldo
Josip Mesec
Mladen Zelenika
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Abstract

In article a two-dimensional photonic crystal (PhC) is considered and modelled as a new generation antireflection coating for optoelectronic devices. Traditional antireflective coatings (ARCs) reduce the reflection of the radiation only – the new generation of antireflective coatings should affect the distribution of the radiation also. Such functionality can be provided by the two-dimensional PhC which reduce the reflection and scatter transmitted light. Prior to the fabrication, the PhCs should be designed and analysed. Results of the analysis should provide quantitative means for choice of materials and design solutions. In work, we analyse the electromagnetic field distribution as Poynting vectors inside the materials of optoelectronic devices, in order to investigate the possibility of improving the construction of future optoelectronic devices. Furthermore, we calculate the reflection and transmission of that ARC. It’s a complex optic analysis of new generation of ARC. The numerical analysis has been performed with the FDTD method in Lumerical Software. In work, we consider the two-dimensional photonic crystal on the top surface of optoelectronic structures. We compared the results with the traditional ARC from these same parameters as PhC: thickness and material. As an example, we presented the application of modelled, photonic crystal, thin-film, GaAs solar cells with PhC on top. The efficiency of this solar cell, using the photonic crystal, was improved by 6.3% over the efficiency of this same solar cell without PhC. Thus, our research strongly suggests that the unique properties of the photonic crystal could be used as a new generation of ARC.

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Authors and Affiliations

D. Przybylski
S. Patela
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Abstract

Polish water resources depend on precipitations, which are variable in time and space. In dry years the water balance is negative in central parts of Poland but sudden thaws and downfalls may result in periodical water excess and dangerous floods almost in the entire country. The retention capacity of artificial reservoirs in Poland permits to store only 6% of the average annual runoff, which is commonly considered insufficient. Another method to increase retention is soil water con-trol. About fifty percent of soils in Poland consist of light and very light sandy soils with low water capacity. Loams and organogenic soils cover approximately 25% and 8.5% area of the country, re-spectively. Almost half of agricultural lands (48%) have relatively good water conditions, but the rest requires soil water control measures. An increase of the soil water content could be achieved by changes of soil properties, water table control and soil water management. Modernization and recon-struction of drainage and irrigation systems, which were built mainly in the period 1960–1980, is needed.

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Authors and Affiliations

Edward Pierzgalski
Jerzy Jeznach
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Abstract

In order to study the dynamic splitting tensile properties of new and old concrete after high temperature treatment, the effects of different impact velocities and temperatures on failure modes, dynamic splitting strength and energy absorption of new and old concrete were analyzed by impact dynamic splitting tensile test use of variable cross-section Φ 74 mm split Hopkinson pressure bar apparatus. The results show that: Impact velocity and temperature not only affect the dynamic splitting strength of new and old concrete bonding specimens, but also affect the failure modes and degree of breakage. The dynamic splitting strength of new and old concrete increases with the increase of impact velocity, but the increase rate decreased with the increase of temperature. The dynamic splitting strength first increases slowly and then decreases dramatically with the increase of temperature. In the dynamic splitting test of new and old concrete, the energy absorption increases with the increase of impact velocity and decreases with the increase of temperature.
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Bibliography

[1] Z.Y. Bu, W.Y. Wu, “Inter shear transfer of unbounded prestressing precast segmental bridge column dry joints”, Engineering Structures, vol. 154, no. 1, pp. 52–65, 2018, DOI: 10.1016/j.engstruct.2017.10.048.
[2] Zhi-fang Zhao et al., “Experimental study on adhesive tensile performance of young on old concrete”, Journal of Building Stucture, vol. 22, no.2, pp. 51–56, 2001.
[3] Zhi-fang Zhao, Guo-fan Zhao, and Cheng-kui Huang, “Research on adhesive bending behavior of young on old concrete”, China Civil Engineering Journal, vol. 33, no. 2, pp. 67–72, 2000.
[4] Li-na Jin et al., “Experimental study of shear performance of new-to-old concrete interface”, Journal of Experimental Menchanics, vol. 29, no. 5, pp. 611–619, 2014.
[5] B.Wang et al., “Evaluation of tensile bonding strength between UHTCC repair materials and concrete substrate”, Construction and Building Materials, vol. 112, pp. 595–606, 2016, DOI: 10.1016/j.conbuildmat.2016.02.149.
[6] A.M. Diab, A.E.M.A. Elmoaty, and M.R.T. Eldin, “Slant shear bond strength between self compacting concrete and old concrete”, Construction and Building Materials, vol. 130, pp. 73–82, 2016, DOI: 10.1016/ j.conbuildmat.2016.11.023.
[7] H.H. Hussein, “Interfacial properties of ultrahigh-performance concrete and high-strength concrete bridge connections”, Journal of Materials in Civil Engineering, vol. 28, no.5, pp. 1943–5533, 2016, DOI: 10.1061/(ASCE) MT.1943-5533.0001456.
[8] A.T. Bassam et al., “Mechanical and permeability properties of the interface between normal concrete substrate and ultra high performance fiber concrete overlay”, Construction and Building Materials, vol. 36, pp. 538–548, November 2012, DOI: 10.1016/j.conbuildmat.2012.06.013.
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[10] Ju-hui Zhang and Yue Li, “Research summary on factors about influencing strength of interfacebetween new and old concrete”, Concrete, vol. 10, pp. 156–162, 2017.
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[13] Bao-jun Pang et al., “Experimental study on impact properties of reactive powder concrete using SHPB after exposure in high temperature”, Journal of Building Materials, vol. 15, no. 3, pp. 317–321, 2012, DOI: 10.3969/j.issn. 1007-9629.2012.03.005.
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Authors and Affiliations

Hai Cao
1
ORCID: ORCID

  1. Huangshan University, School of Civil Engineering and Architecture, HuangShan 245041,China
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Abstract

A composition of lipids of some Antarctic Crustacea (Euphausia superba. E. triacantha. Thysanoessa macrura and Mysidacea gen. sp. indet.) caught in the Admiralty Bay (South Shetlands) was compared. Lipids of E. superba differed in low content of waxes that evidences for different management of lipids than in other examined Crustacea.

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Authors and Affiliations

Anna Kołakowska
ORCID: ORCID
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Abstract

The author defines the following: terrorist act; terrorism; ecological terror; terrorist threats; illegal use of terror; terrorist acts in internal and international law. The article discusses terrorism in light of Polish and European law and ecological safety and terrorism (eco-terrorism). Issues o f ecological safety in Europe were addressed in Helsinki in 1975 at the meeting of nations participating in the Conference on Safety and Co-operation in Europe. In the twenty-first century, the general regulations regarding fighting terrorism are applied to ensure ecological safety. Specifically, this refers to the European convention on fighting terrorism laid out in Strasbourg on January 27, 1977 under the auspices of the Council of Europe. The author addressed the issue of actions taken by radical ecologists within the framework of the activities of non-governmental ecological organizations. Actions of a terrorist character undertaken at sea are also discussed. Establishing a contiguous marine coastal zone is an effective method for fighting terrorism.

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Authors and Affiliations

Janina Ciechanowicz-McLean
ORCID: ORCID
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Abstract

The paper reports on investigation and development of a flywheel device intended for an energy storage prototype. The goal was to design and experimentally verify the concept of self-integrated flywheel with smart control of energy flow and accumulation. The Flywheel Energy Storage System (FESS) must has high energy efficiency and structural robustness. Investigation on structural dynamics of the composite flywheel connected with outer type rotor was carried out using Finite Element Method. The FESS is designed to run in vacuum and is supported on low-energy, controlled, active magnetic bearings (AMBs). The flywheel device of 10 MJ energy density and a weight of 150 kg with two integrated rotors/generators of 50 kW power density each is intended to operate up to 40 000 rpm.

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Authors and Affiliations

Arkadiusz Mystkowski
Artur Rowiński
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Abstract

In the interview, Dipesh Chakrabarty gives an insight into recent transformations of historical thinking and writing. He discusses various faces of recent democratisation of history, like the proliferation of environmental history and the decolonialisation perspective. He outlines the genealogy of the term “provincializing”, known from his notable work Provincializing Eu-rope. Finally, he elaborates on the emergence of “the planetary” (or “a planetary age”) and recalls the contributions of Martin Heidegger and Carl Schmitt on the conceptualisation of the issue.
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Authors and Affiliations

Tomasz Wiśniewski
1
ORCID: ORCID

  1. Uniwersytet im. Adama Mickiewicza w Poznaniu
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Abstract

The article presents the history of private life as a new trend in historical research initiated by Philipe Aries and taken up by historians connected with anthropological history. The Author focuses on the problem of privacy as a concept occuring in the fields of sociology and psychology and tries to determine the domain of the history of private life. Special stress is put on the differences between the discussed branch of history and the history of everyday life.
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Authors and Affiliations

Barbara Klich

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