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Abstract

Low-frequency mechanical vibrations can trigger disasters such as coal-gas outbursts. An in-house “vibration-triaxial stress-seepage” experimental apparatus was used to measure the gas flow rate of rock specimens with varying vibrational frequency, gas pressure, and confining pressure. The results of these tests were then used to derive expressions that describe how the permeability of gas-containing coal rocks is related to these aforementioned factors. In addition, sensitivity coefficients were defined to characterise the magnitude of the permeability response to each permeability-affecting factor (i.e., vibrational frequency and gas pressure). The following insights were gained, regarding the effects of vibrational frequency on the permeability of gas-containing coal rocks: (1) If gas pressure and confining pressure are fixed, the permeability of gas-containing coal rocks rapidly increases, before gradually decreasing, with increasing vibrational frequency. Thus, the permeability of the gas-containing coal rock is always larger with vibrations than without. (2) If vibrational pressure and confining pressure are fixed, the relationship between the permeability of gas-containing coal rocks and gas pressure is consistent with the “Klinkenberg effect,” i.e., the permeability initially decreases, and then increases, with increasing gas pressure. (3) The change in permeability induced by each unit change in gas pressure is proportional to the gas pressure sensitivity coefficient. (4) The change in permeability induced by each unit change in vibrational frequency is proportional to the vibrational frequency sensitivity coefficient.
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Authors and Affiliations

Zhu Bairu
1
ORCID: ORCID
Song Yang
1
ORCID: ORCID
Wu Beining
1
ORCID: ORCID
Li Yongqi
1
ORCID: ORCID

  1. Liaoning Technical University, School of Civil Engineering, Fuxin, Liaoning, 123000, China
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Abstract

Notothenia coriiceps, N.rossii and Lepidonotothen nudifrons were sampled from Admiralty Bay from March to November 1997 and from January to February 1999. The ratio of N.coriiceps to N.rossii individuals in catches regularly increased during 22 years from 0.4 in 1977 to 9.5 in 1999. Oving to its reproductive strategy and avoidance of shallow waters N.rossii may be more vulnerable to overfishing. The condition factor was the most stable (CV 6 -10%), variations in the of hepatosomatic index and index of stomach fullness were intermediate (21 -38%and 40 -43%,respectively), and the gonadosomatic index was the most variable (65 -100%). Lack of seasonality in two somatic indices (condition factor and index of stomach fullness) in N.coriiceps adults is a direct effect of high food availability and unlimited food detection all year round. In contrast, the seasonality of a reproductive index (gonadosomatic index) of these fish is a response to the highly seasonal trophic conditions for pelagic larvae.

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Authors and Affiliations

Ewa Kamler
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Abstract

The article discusses problems related to rules and regulations determining compensations for the mining usufruct of mineral deposits covered by the so called “state mining ownership”. Specific acts of law framing agreements on mining usufruct between government and mining enterprises were analyzed. Rules and algorithms applied to calculate an appropriate compensation are evaluated leading to several conclusions, including the one about lack of a direct legal grounding for them. Such a situation creates disputes and may be risky for all involved. It was also indicated that, in parallel, the State lets another class of mineral deposits, namely the ones owned as a result of real estate ownership and the related Civil Code regulations confirmed by the mining law. In such cases, a mining entrepreneur gets usufruct of a real estate, but only the one with mineral rights. Subsequently a comparison of the rules and algorithms established for determining compensation for mining usufruct and for usufruct of real-estates comprising rights for mineral assets was performed. Arguments for a far going harmonization between these two were put forward. This implies that a starting point for determining any compensation has to be a valuation of a relevant mineral deposit market value as opposed to any universal, however complicated, prescribed algebraic formula. Such a process is complicated and demands competences in geology, mining and finance. Consequently, regulations set in the Polish Mineral Asset Valuation Code shall be applied to both a running a valuation process and indicating competent persons. As a result, recommendations leading to correlate rules applied in both cases are put forward including the adoption of mineral asset valuation as a fundament to determine the level of compensation for the mining usufruct. The closing section contains recommendations regarding necessary changes in the legal framework.

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Authors and Affiliations

Ryszard Uberman
Robert Uberman
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Abstract

Statystyczny Polak spędza przeciętnie około 20% swojego życia na wykonywaniu pracy zawodowej, stąd działania pracodawcy, jego służb bhp i organów państwowej kontroli skupiają się nad zapewnieniem możliwie jak najbardziej bezpiecznych warunków środowiska pracy. Całkowite wyeliminowanie z otoczenia pracownika czynników, będących źródłem zagrożeń niebezpiecznych, szkodliwych bądź uciążliwych, w wielu przypadkach jest zadaniem trudnym, a często niemożliwym. Wynika to z faktu, iż dany czynnik stanowić może podstawową składową procesu technologicznego i nie może zostać wykluczony, tak jak to ma miejsce w przypadku prac szczególnie niebezpiecznych, np. podczas używania materiałów wybuchowych przeznaczonych do użytku cywilnego. W takim wypadku szczegółowa identyfikacja oraz ocena poziomu zagrożeń, uwzględniająca wiedzę ekspercką z zakresu stosowanych środków strzałowych oraz technologii, stanowi przyczynek do wzrostu poziomu bezpieczeństwa pracownika pomimo stosowania niebezpiecznych substancji, niebezpiecznych środków pracy czy niebezpiecznych technologii. W trakcie eksploatacji metodą odkrywkową jednym z najczęściej stosowanych sposobów odspojenia i rozdrobnienia złoża skalnego jest użycie materiałów wybuchowych. Taka technika urabiania powoduje konieczność zatrudnienia pracowników na stanowiskach specjalistycznych, na których występuje wiele zagrożeń tzw. ogólnokopalnianych oraz tych wynikających z bezpośredniej ekspozycji na czynnik niebezpieczny, jakim są środki strzałowe. W niniejszym artykule przedstawiono szczegółową identyfikację zagrożeń na stanowiskach związanych z używaniem materiałów wybuchowych, uwzględniającą wykonywane czynności podczas realizacji robót strzałowych w górnictwie odkrywkowym oraz zróżnicowanie tych zagrożeń w przypadku stosowania różnych systemów inicjowania materiałów wybuchowych. Po zidentyfikowaniu zagrożeń dokonano ich hierarchizacji z wykorzystaniem metody Analytic Hierarchy Process (AHP), która jest jedną z technik wielokryterialnego podejmowania decyzji, umożliwiającą bezpośrednie porównanie między sobą i szeregowanie według przyjętych kryteriów analitycznych. Na podstawie wyników przeprowadzonych analiz sporządzono ocenę macierzową dla wyznaczenia poziomu ryzyka zagrożeń dla specjalistycznego stanowiska pracy w ruchu odkrywkowego zakładu górniczego – górnika strzałowego.

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Authors and Affiliations

Michał Dworzak
Dagmara Nowak-Senderowska
Józef Pyra
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Abstract

Common spoken and written Polish (literary language) belongs to the European languages which have been sufficiently influenced by biblical writings (language). Relationships between literary language and the language of the biblical translations can be described as mutual influence of various intensity as far as the direction, time, intensification, endurance and level of the language are concerned. The article deals with the examples of the influence of the biblical translations on the literary language as for its intellectualisation, lexical and phraseological enrichment as well as stylistic development.

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Authors and Affiliations

Danuta Bieńkowska

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