Case studies and analysis of mine shafts incidents in Europe

International audienceEntry to mine workings is normally gained by means of vertical shafts or horizontal or inclined tunnels called adits. Other mining objects such as fan drifts and wheel pits are often associated with mine shafts. Such mining objects may or may not have been filled, wholly or partially, or otherwise sealed to prevent entry when the mine was abandoned. Nowadays mine entries are usually adequately protected on abandonment to prevent accidental ingress. Many earlier mine entries remain open, however, and may pose a threat to human safety. Within the framework of MISSTER (Mine shafts: improving security and new tools for the evaluation of risks), a European RFCS project (Research Fund for Coal and Steel), a selection of representative cases of mine shafts incidents was reviewed. This work was carried out by INERIS (France), GEOCONTROL (Spain), University of Nottingham and Mine Rescue Service Ltd (United Kingdom), Central Mining Institute and KWSA (Poland). The experience accumulated through this work will allow a fuller determination of risk scenarios associated with mine shafts

Numerical modeling of the rock mass around an excavation exposed to mining-induced pressure

W artykule przedstawiono próbę odwzorowania za pomocą modelowania numerycznego, zachowania się górotworu wokół wyrobiska przyścianowego znajdującego się w strefie oddziaływania przesuwającego się frontu eksploatacyjnego. Próby te zostały przeprowadzone w oparciu o wybrane wyniki dołowych pomiarów konwergencji chodników przyścianowych w kopalniach węgla kamiennego.This paper presents results from numerical modeling of the rock mass around an excavation which is exposed to different mining-induced pressure. The numerical modeling was based on the in-situ measurement in the longwall tailgates. The measurements were carried out in the Polish hard coal mines

Optymalizacja obudowy skrzyżowania ściana-chodnik, zlokalizowanego pod zrobami zawałowymi

The paper contains results of underground tests of support load in the area of a face-roadway junction. Results of numeric computations of the influence of placing steel horseheads, props and the preparing technological niches ahead of the face of the wall on the support load-bearing capacity near the junction are presented.Skrzyżowania ściany z chodnikami przyścianowymi są obszarem decydującym o prowadzeniu prawidłowej eksploatacji pokładów węgla kamiennego. Jednocześnie są to miejsca, w których często dochodzi do zdarzeń niebezpiecznych i wypadków, z uwagi na liczbę przebywających w tym rejonie pracowników, wykonujących pracochłonne i niebezpieczne czynności związane na przykład z obudową samego skrzyżowania, jak i wlotu do ściany. Zagrożenie dla pracującej w rejonie skrzyżowań załogi wynika również z ograniczonej przestrzeni roboczej z uwagi na elementy wyposażenia ścianowego, głównie napędu przenośnika. Poziom zagrożenia wzrasta w przypadku, kiedy prowadzi się eksploatację pokładu o znacznej miąższości z zawałem stropu, z podziałem na warstwy. Takie przypadki opisano w niniejszym referacie, kiedy to skrzyżowania ścian z chodnikami zlokalizowane były pod zrobami warstw wyżej wybranych. Referat zawiera wyniki badań dołowych obciążenia obudowy w rejonie skrzyżowania ściana-chodnik. Przedstawiono również rezultaty obliczeń numerycznych różnych wariantów obudowy skrzyżowań. Na podstawie wyników badań oraz obliczeń numerycznych dokonano oceny możliwego kierunku działania wypadkowej obciążenia obudowy skrzyżowania ściana-chodnik

Maintenance of the gateroad behind the front of the longwall at great depths – case study

W artykule przedstawiono sposoby wzmocnienia chodnika przyścianowego, który ze względów wentylacyjnych utrzymywany był za frontem ściany. Omówiono dotychczas stosowane schematy wzmocnień w KWK „Budryk” oraz zaprezentowano trzy nowe schematy zastosowane na długości analizowanego wyrobiska. Celem przedstawionych prac, oprócz typowo utylitarnego charakteru - utrzymania odpowiedniego przekroju poprzecznego - była również odpowiedź na pytanie, jakie schematy mogą zostać z powodzeniem zastosowane w chodnikach przyścianowych zlokalizowanych na głębokościach większych od 1000 m.This paper presents the methods of reinforcing a gateroad, which due to ventilation purpose has been maintained behind the front of the longwall. Previously used schemes of reinforcements in „Budryk” hard coal mine were discussed, and three new schemes applied along the length of the analyzed gateroad. The aim of this work, in addition to the typical utilitarian nature - to maintain an adequate cross-section of the openings - was also to find out what schemes may be successfully applied in the gateroads located at depths greater than 1000 m

Metabolizm serotoniny u dzieci zarazonych Giardia intestinalis

According to the data from the last 4 years, 3.8% of all diagnosed parasitoses are giardiases. During 5 years Giardia intestinalis was found in 24 chiidren hospitalized in the General Hospital of the Wrocław Voivodship: in 14 girls and 10 boys, 2-12 years old. The parasite was identified coproscopically and on the basis of clinical symptoms. Before the medication, the blood was taken from each child to determine the serotonin level and the (MAO) monoaminooxydaze, enzyme metabolizing serotonin acivity in the blood serum. The results were compared to the values obtained in the control group of 10 healthy children, 3-12 years old. III children were divided into two groups: first consisted of 12 children, 2-5 years old, second - of 12 children, 6-12 years old. In the first group 210% increase of the serotonin level in the blood and slight 32,4% increase of the MAO activity were observed in comparison with the control group. In the second group the serotonin level in the blood increased 221 % in comparison with the control, while the MAO actmty increased 45.1 %. In older children marced clinical symptoms could be observed, mainly malfunction of the alimentary tract, microelements shortage and anemia. The highest level of serotonin and MAO activity was found in the child with bile duet irritation. The reason for the increased level of serotonin and MAO activity can be pathogenic action of parasite's trophozoites and cysts on the jejunum mucosa and mobilization, proliferation and degranulation of tissue mastocytes. Serotonin, released from mastocytes, can be the cause of enhanced peristalsis and mucosa congestion

Metabolizm serotoniny u dzieci zarażonych Giardia intestinalis

According to the data from the last 4 years, 3.8% of all diagnosed parasitoses are giardiases. During 5 years Giardia intestinalis was found in 24 chiidren hospitalized in the General Hospital of the Wrocław Voivodship: in 14 girls and 10 boys, 2-12 years old. The parasite was identified coproscopically and on the basis of clinical symptoms. Before the medication, the blood was taken from each child to determine the serotonin level and the (MAO) monoaminooxydaze, enzyme metabolizing serotonin acivity in the blood serum. The results were compared to the values obtained in the control group of 10 healthy children, 3-12 years old. III children were divided into two groups: first consisted of 12 children, 2-5 years old, second - of 12 children, 6-12 years old. In the first group 210% increase of the serotonin level in the blood and slight 32,4% increase of the MAO activity were observed in comparison with the control group. In the second group the serotonin level in the blood increased 221 % in comparison with the control, while the MAO actmty increased 45.1 %. In older children marced clinical symptoms could be observed, mainly malfunction of the alimentary tract, microelements shortage and anemia. The highest level of serotonin and MAO activity was found in the child with bile duet irritation. The reason for the increased level of serotonin and MAO activity can be pathogenic action of parasite's trophozoites and cysts on the jejunum mucosa and mobilization, proliferation and degranulation of tissue mastocytes. Serotonin, released from mastocytes, can be the cause of enhanced peristalsis and mucosa congestion

Age-dependent altered proportions in subpopulations of tonsillar lymphocytes

Age-related changes in functional subsets of lymphocytes may influence the potential to build up immune responses. In particular, the capacity of tonsillar lymphocytes to counter infections may be altered during ageing. In order to address this question we investigated the proportional distribution of several subsets of tonsillar T and B cells with regard to ageing. Tonsils were derived from 119 patients between 2 and 65 years of age. Lymphocyte subsets were monitored by three-colour fluorescence of relevant CD markers in flow cytometry. As a general tendency the percentage of CD3+ T cells steadily increased whereas that of CD19+ B cells decreased at the same time. No significant differences were observed between lymphocytes of patients with and without inflammatory history of the tonsils. The percentage of CD8+ T cells declined whereas that of CD4+ T cells increased during the same time span. CD45RA+ T cells increased during the first two decades of life and gradually decreased thereafter. In contrast, CD45RO+ T cells showed an opposite trend. No differences were seen in the population of CD3−/CD56+ natural killer (NK) cells. The mature B cell marker CD40 showed no significant changes during ageing. However, CD38+ B cells, representing B cells of late maturation stages, dramatically declined up to the age of 65. In a similar manner the CD5+ subpopulation of B cells decreased during ageing. Substantial changes in major tonsillar T and B cell populations as shown in this study may have an impact on the ageing process of the immune system