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Abstract

For majority of running waters point pollution sources are the main sources of pollution. Knowing the water self-purification capacity one can modify the quality of waters through proper management of the discharged pollutants. This study focuses on identifying such solutions for pollutant discharge into the Kłodnica and Bytomka rivers, which would allow for achieving at least the Ill class of surface water quality. Simulation of selected wastewater management scenarios was carried out. The best solutions for the water environment were identified. Only environmental effects which resulted in improvement of the water quality were analyzed. The economical aspect of actions, the undertaking ofwhich is indispensable for achieving the assumed goal, was not taken into account. The selection of the best solutions considering the cost effectiveness cannot be made until a feasibility study for particular undertakings has been completed. Sal i nity and biodegradable pollutants determined by BOD coefficient were taken into consideration. The simulation was carried out using an integrated simulation model IRM (Integrated River Model). In order to protect the river from excessive salinity the optimum solution for the Bytomka River would be desalination, whereas for the Kłodnica River- directing salty mining waters outside its catchment. For protection from biodegradable pollutants the only solution would be tightening the effectiveness criteria for municipal wastewater treatment. Meeting the minimum standards for wastewater treatment, currently obligatory in municipal wastewater treatment plants, will not ensure the assumed water purity level in these rivers.
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Authors and Affiliations

Rudolf Bujok
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Abstract

2D position error in the Global Positioning System (GPS) depends on the Horizontal Dilution of Precision (HDOP) and User Equivalent Range Error UERE. The non-dimensional HDOP coefficient, determining the influence of satellite distribution on the positioning accuracy, can be calculated exactly for a given moment in time. However, the UERE value is a magnitude variable in time, especially due to errors in radio propagation (ionosphere and troposphere effects) and it cannot be precisely predicted. The variability of the UERE causes the actual measurements (despite an exact theoretical mathematical correlation between the HDOP value and the position error) to indicate that position errors differ for the same HDOP value.
The aim of this article is to determine the relation between the GPS position error and the HDOP value. It is possible only statistically, based on an analysis of an exceptionally large measurement sample. To this end, measurement results of a 10-day GPS measurement campaign (900,000 fixes) have been used. For HDOP values (in the range of 0.6–1.8), position errors were recorded and analysed to determine the statistical distribution of GPS position errors corresponding to various HDOP values.
The experimental study and statistical analyses showed that the most common HDOP values in the GPS system are magnitudes of: 0.7 (�� = 0•353) and 0.8 (�� = 0•432). Only 2.77% of fixes indicated an HDOP value larger than 1. Moreover, 95% of measurements featured a geometric coefficient of 0.973 – this is why it can be assumed that in optimal conditions (without local terrain obstacles), the GPS system is capable of providing values of HDOP ≤ 1, with a probability greater than 95% (2��). Obtaining a low HDOP value, which results in a low GPS position error value, calls for providing a high mean number of satellites (12 or more) and low variability in their number.
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Authors and Affiliations

Mariusz Specht
1

  1. Department of Transport and Logistics, Gdynia Maritime University, Morska 81-87, 81-225 Gdynia, Poland
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Abstract

The aim of this publication is to design a procedure for the synthesis of an IDT (interdigital transducer) with diluted electrodes. The paper deals with the surface acoustic waves (SAW) and the theory of synthesis of the asymmetrical delay line with the interdigital transducer with diluted electrodes. The authors developed a theory, design, and implementation of the proposed design. They also measured signals. The authors analysed acoustoelectronic components with SAW: PLF 13, PLR 40, delay line with PAV 44 PLO. The presented applications have a potential practical use.

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Authors and Affiliations

Milan Šimko
Miroslav Gutten
ORCID: ORCID
Milan Chupáč
Matej Kučera
Adam Glowacz
ORCID: ORCID
Eliasz Kantoch
Hui Liu
Frantisek Brumercik
ORCID: ORCID
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Abstract

This experiment aimed to determine the effect of adaptive duration to saline water on behaviors, weight gain and blood biochemical parameters in growing goats. The experiment was arranged in a completely randomized design, which included four treatments with five animals per group. The goats were administered either fresh water (control) or seawater with a salinity of 1.5%, with varying durations of adaptation to seawater. The adaptive durations included an abrupt change (A0) from fresh water to seawater with a salinity of 1.5% or stepwise adaptation either 4 (A4) or 7 (A7) days of increasing saline concentrations. The results showed that dry matter intake in the non-adapted goats (A0 group) was lower than that of the control group or the adapted goats throughout the experiment (p<0.05). In contrast, water intake from drinking saline water was greater than that in the control group (p<0.05). Body weigh did not differ among the treatments; however, non-adapted goats exhibited a lower weight gain than the adapted goats (p<0.05). The goats in the A0 and A4 groups exhibited increased plasma levels of urea, AST, and ALT compared with the control and A7 groups. However, blood electrolyte levels remained unchanged and were within the normal range for goats. Therefore, it is concluded that the stepwise adaptation to seawater with a salinity of 1.5% for 21 days has no influence on productivity and health status of goats.
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Bibliography

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Authors and Affiliations

T. Nguyen
1
N. Nguyen Trong
2
N. Chaiyabutr
3
S. Thammacharoen
3

  1. Department of Agricultural Technology, College of Rural Development, Can Tho University, 3/2 street, Can Tho city 94000, Vietnam
  2. Department of Animal Science, College of Agriculture, Can Tho University, 3/2 street, Can Tho city 94000, Vietnam
  3. Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, HenriDunang street, Bangkok 10330, Thailand
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Abstract

The study has been carried out at two experimental sites. It aims to assess the impact of the reuse of raw wastewater, purified and diluted with conventional water on the physicochemical quality of soils compared to irrigated soils with con-ventional drilled water and non-irrigated soil. The obtained results show that the electrical conductivity EC and sodium gradually increase in all the plots irrigated with wastewater. Additionally, a slight increase in the pH levels at the first site and a slight decrease in the second site was seen, but at both sites the soils remained alkaline. The infiltration rate of water slide decreases in relation to the amount of irrigation, especially in plots irrigated by raw and treated wastewater. For the same plots, the values of organic matter increased, and the values obtained for the exchangeable sodium percentage (ESP) became high in the third year and reached 17.0% and 16.7% respectively.
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Authors and Affiliations

Smail Njimat
1
ORCID: ORCID
Fouad Elfettahi
2
Hajar Griou
1
ORCID: ORCID
Mohammed Y. El Brouzi
3
Mohammed Aboulouafa
1
ORCID: ORCID
Said Ibn Ahmed
1

  1. Laboratory of Materials, Electrochemistry and Environment, University Ibn Tofail, Faculty of Sciences, Department of Chemistry, 14200, Kenitra, Morocco
  2. Agricultural Technical Institute, Ain Taoujdate, El Hajeb, Morocco
  3. Laboratory of Genetics, Neuroendocrinobiology and Biotechnology. Faculty of Sciences, Department of Biology
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Abstract

Sublevel caving (SLC) mining method has several features that make it one of the preferred methods for ore extraction due to its high productivity and early access to ore recovery. However, there are some major challenges associated with the SLC method such as ground surface subsidence, high unplanned ore dilution, and the potential for air blast. To remedy these shortcomings, a recent approach has been to modify the SLC method by introducing rockfill into the void atop the production zone to provide continued support for the host rock and prevent it from caving. This paper discusses in detail the merits of the Modified SLC or MSLC. In comparison with other long-hole stoping methods that are predominantly practiced in metal mines, the MSLC method boasts several advantages. Early production achieved from the topmost level helps reduce the payback period. Productivity is enhanced due to multilevel mining without the use of sill pillars. The cost of backfilling is significantly reduced as there is no need for the construction of costly backfill plants. Continuous stoping is achieved without delays as mining and backfilling take place concurrently from separate mining horizons. A significant reduction in underground development costs is achieved as fewer slot raises and crosscuts are required for stope preparation. These merits of the Modified SLC method in steeply dipping orebodies are discussed by way of reference to real-life mine case studies. Dilution issues are addressed, and the benefits of top-down mining are explained. Typical mine design, ventilation, materials handling, and mining schedules are presented. Geomechanics issues associated with different in-situ stress environments are discussed and illustrated with simplified mine-wide 3D numerical modeling study.
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Authors and Affiliations

Kenneth K. Adams
1
ORCID: ORCID
Tuo Chen
1
ORCID: ORCID
Atsushi Sainoki
2
ORCID: ORCID
Hani S. Mitri
1
ORCID: ORCID

  1. McGill University, Canada
  2. Kumamoto University, Japan

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