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Number of results: 10
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Abstract

Acid mine drainage (AMD) is widespread environmental problem associated with both working and abandoned mining operation, resulting from the microbial oxidation of pyrite in presence of water and air, to form an acidic solution containing metal ions. The present study aims to adjust low pH, remove iron, manganese and sulphate from AMD generated at open pit Jiří and depth Jiří, Sokolovská uhelná, Czech Republic. The local AMD is very problematic due to its composition and process taking place in the Water Preparing Plant Svatava (WPPS), where only pH value is adjusted and mainly high concentration of iron and suspended solids are removed.

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Authors and Affiliations

Silvie Heviánková
Iva Bestová
Miroslav Zechner
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Abstract

Hydroacoustic projectors are useful for generating low frequency sounds in water. Existing works on hydroacoustic projectors require two significant enhancements, especially for designers. First, we need to understand the influence of important projector design parameters on its performance. Such insights can be very useful in developing a compact and efficient projector. Second, there is a need for an integrated model of the projector based on easily available and user-friendly numerical tools which do not require development of complex customised mathematical analogs of projector components. The present work addresses both such needs. Towards these goals, an experimentally validated, easy-to-build projector model was developed and used to conduct design sensitivity studies. We show that reductions in pipe compliance and air content in oil, and an increase in orifice discharge coefficient can yield remarkable improvements in projector’s SPL. We also show that reductions in pipe length and cylinder diameter cause moderate improvements in performance in mass and stiffness controlled regions, respectively. In contrast, the projector performance is insensitive to changes in pistonic mass, cylinder length, and diaphragm stiffness. Finally, we report that while pipe compliance and air content in oil can sharply alter system resonance, the effects of changes in pipe length and pistonic mass on it are moderate in nature.
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Authors and Affiliations

Vattaparambil Sreedharan Sreejith
1
Nachiketa Tiwari
1

  1. Dhwani Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Uttar Pradesh 208016, India
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Abstract

Processes applied for preliminary treatment of wastewater from refineries and petrochemical plants create the oily sludge, containing high percentage of water and only a bit less of hydrocarbons. This sludge is collected in storage tanks, because no application for it can be found. Our researches had as a first step the aim to convert this fluid sludge into solid substance (product) by adding of quicklime and then utilize the product in the road construction as a bottom layer of the road. The product should be added in the amount of a few percent comparing to the rest of soil. The second step of the research was an assessment of an impact of the product used for construction of experimental sections of roads and squares on environment by monitoring of surface and ground water quality in their vicinity. If the contribution of the product in total amount of the road material is less than 8% the influence is kept under limits.
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Authors and Affiliations

Bronisław Bartkiewicz
Iwona Obierak
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Abstract

The use of non-centralised water supply in remote settlements is currently the only possible option. Monitoring the wa-ter quality of such supply sources is a complicated task in such areas, especially when there are active karst processes and difficult groundwater conditions. The application of deterministic analytical models of water supply under the risk of dis-turbance to groundwater dynamics is not efficient. Significant quantitative and even qualitative changes in groundwater conditions may take place between the calculated points, and the underestimation of these changes in expectation-driven computation models may result in serious geoecological issues. This research studied and justifies the use of adaptive dy-namic hydrogeological control in an area of non-centralised water supply based on the identification of key zones of geo-dynamic karst monitoring and the electrical express-monitoring of water resources. The identification of key zones is based on an integrated analysis of available groundwater information that describes changes in groundwater hydrodynamic condi-tions at the time of the karst forecast. The development of karst-suffusion processes is accompanied by more intense dy-namic changes in local areas of geologic environment compared to the general variation in intensity. Information about the occurrence of destructive groundwater processes by means of selective geodynamic monitoring may thus be obtained much earlier than with environmental geodynamics monitoring as a whole. The experimental hydrogeological control of an area of non-centralised water supply was conducted on the right bank of the Oka River in Nizhny Novgorod region, a locality with an active manifestation of karst processes. Structure and algorithms of space-time processing of hydrogeological con-trol data developed by authors have been used. The approach based on multifrequency vertical electrical sounding (MFVES) method has shown good correspondence with direct borehole observation when measuring depth of the first aq-uifer. Zones of unsafe water use have been revealed. The results demonstrated the effectiveness of the proposed method and the need for further regular observations of destructive groundwater processes by means of selective hydrogeodynamic monitoring.

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Authors and Affiliations

Oleg R. Kuzichkin
ORCID: ORCID
Roman V. Romanov
ORCID: ORCID
Nikolay V. Dorofeev
ORCID: ORCID
Anastasia V. Grecheneva
ORCID: ORCID
Gleb S. Vasilyev
ORCID: ORCID
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Abstract

The author’s aim was to present actual conditions of rural primary schools functioning and the spatial differentiation of their network reorganization with particular emphasis on the consequences of those schools liquidation change their a governing body other from the local government units (LGU) to local community organizators. The study was focused on rural areas of the Małopolskie Voivodship over 2000–2016 period. In the paper were presented the number of pupils and schools (open and closed) and the school governing bodies structure too. Those data, obtained by the author from the Local Data Banks and the Board of Education in Cracow and were presented for each statistical locality. A population and settlement concentration in many rural areas made costs of schools maintenance higher and higher. Thus school governing bodies faced a difficult decision – either to reorganize the actual school network or to spend more on education from the municipal budget. Most complicated structures is observed in the rural areas showing depopulation and dispersed settlement, the zones of traditional agricultural. In all rural areas of the Małopolskie Voivodship, the number of pupils in primary schools during the analysed period decreased nearly by 30%. Thus 118 small rural schools were closed i.e. in the county Miechów, of 43 schools remained only 21. The number of closed schools would be much higher without a activity of the local communities, which began to take over their schools from the LGU. Within rural areas the Małopolskie Voivodship in 2016, 123 schools were run by local organization i.e. over 11,5% of all the rural primary schools.

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Authors and Affiliations

Marcin Semczuk
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Abstract

The thermodynamic properties, which are the important bulk properties for solids, have been investigated for ZrB2 under pressure through the quasi harmonic Debye model. The dependences of thermal expansion, Gruneisen parameter, Debye temperature and specific heat on pressure P are successfully obtained. The obtained results are in a good agreement with the available experimental and other theoretical data.

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Authors and Affiliations

Tanveer Ahmad Wani
Basant Kumar Das
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Abstract

Characterisation of two-spotted spider mite ( Tetranychus urticae Koch , Acari: Tetranychidae) response to aqueous extracts from selected plant species. Aqueous extracts from four plant species of known insecticidal activity on arthropods were tested against two-spotted spider mite females to describe their mode of action on the spider mite. The extracts effects on: (a) the mite establishment on host plant; (b) initiation of feeding (probing behaviour); (c) initiation of permanent feeding and (d) the mite mortality (a toxic effect) was measured using various experimental techniques. The highest toxic action was shown by NeemAzal-T/S (an extract from Azadirachta indica; production of Trifolio-M GmbH company) and repellent by water extract from Allium sativum and Urtica dioica. NeemAzal T/S also shown a strong activity as a feeding suppresant for T. urticae.

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Authors and Affiliations

Zbigniew T. Dąbrowski
Urszula Seredyńska
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Abstract

In order to rebuild a poetic voice that had been threatened by major historical events, from 1958, the Nerudian poetic subject inaugurated a particular sincerity through the humor. By focusing on a figure of language described by Nicholas Manning in Rhétorique de la sincérité, this paper examines a dialectical mechanism at work in the volume: which is the rehabilitation of the poetic voice by means of the very questioning of his legitimacy.
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Authors and Affiliations

Mélina Cariz
1
ORCID: ORCID

  1. Lycee François Mansart, Saint-Maur Des Fosses, France
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Abstract

The aim of this study was to design and test an adjustable hydro-pneumatic damper for cab suspension. The goal was to make a simple and cheap solution for a damper, which is intended to be placed between the hydraulic cylinder and accumulator. Damping behaviour of different terrain types had to be taken into consideration. Terrain type varies from field to road driving and damping should react rapidly to varying conditions.

In this study, the semi-active damper has been built with a hydraulic direct acting cartridge type 2/2-way proportional flow control valve. Flow-pressure curves and dynamic tests were carried out in the laboratory. The dynamic test with forced vibration focused on stability in damping frequencies and step response between different states. Also, total damping force was measured in different damping states and the proportional valve’s precise step responses and stability were investigated in a closed hydraulic system.

As a result, this research gave a lot of new information about the proportional valve’s applicability to work as a semi-active damper and information about damping behaviour. Research showed that a proportional valve can work in a cab suspension damper as well as a multi-fixed orifice damper. Bi-directional flow in the proportional valve was found to remain stable in cab suspension working conditions. The proportional valve also has the ability to work as a continuous state damper, which could lead to better damping results with the appropriate control system.

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Authors and Affiliations

Pasi Ruotsalainen
Kalervo Nevala
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Abstract

In 1972 a seventeenth century wooden church has been moved from Bączal Dolny to an open-air museum. Over 30 coins dating back to a period ranging between the middle seventeenth century and the middle twentieth century have been found in thxe place where the church used to be located. Lack of older coins proves that if there was another church in this area before the 1600s, it could not have been erected on the same spot.

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Authors and Affiliations

Krzysztof Wnęk

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