Results 1 - 10 of 12245
Results 1 - 10 of 12245. Search took: 0.047 seconds
|Sort by: date | relevance|
[en] We search for continuous gravitational waves from PSR J0835-4510 at twice its rotational frequency using CLIO (Cryogenic Laser Interferometric Observatory) in the Kamioka mine. In this search, we use data from an observational run during 12-28 February 2007. We give a brief description of the methods used in this search. We obtain an upper limit on gravitational wave amplitude for PSR J0835-4510 as h0(UL) = 5.3 x 10-20 with 99.4% confidence level
[en] This order provides for the creation, attributions and organization of Departemental Directorates, Direction of urban Niamey's communauty and Arlit's Arrondissement Service of the Ministry of Mines and Energy. It is created a Departmental Directorate of Mines and Energy into each of the following places of region: AGADEZ, DIFFA, , MARADI, TAHOUA, TILLABERI and ZINDER, and Direction of urban Niamey's communauty and Arlit's Arrondissement Service of the Ministry of Mines and Energy. Each Departmental and communal Directorate is constitued of: a service of the Geology's Research and Mining, Mines service, a Service of Electricity and new Energies and renewlables, a Service of hydrocarbures and an Administrative and Financial Service. Arrondissement Service includes: a Division of Mines and Geology, a Division of Energy and an admistrative and Financial Division.
[fr]Cet arrete porte sur la creation, attributions et organisation des Directions Departementales, et de la Direction de la Communaute Urbaine de Niamey et du Service d'Arrondissement d'Arlit du Ministere des Mines et de l'Energie. Anisi, il est cree une Direction Departementale des Mines et de l'Energie dans chacun des chefs lieux de departement suivants: AGADEZ, DIFFA, MARADI, TAHOUA, TILLABERI et ZINDER; et une Direction de la Communaute Urbaine de Niamey et du Service d'Arrondissement d'Arlit du Ministere des Mines et de l'Energie. Une Direction Departementale est constituee de cinq Services: Service de la Recherche Geologique et Miniere, Services des Mines, Service de l'Electricite et des Energies Nouvelles et Renouvelables, Service Administratif et Financier, Service des Hydrocarbures. Les Directions Regionales sont chargees du suivi et controle de l'application des dispositions du code minier, du code petrolier et du code de l'electricite ainsi que l'application de toutes les dispositions reglementaires relatives au secteur des Mines et de l'Energie. Le Service d'Arrondissement comprend : une Division des Mines et de la Geologie, une Division de l'Energie, une Division Administrative et Financiere.
[en] The contents of this book are aspect of tunnel collapse, type of tunnel collapse, mechanism of tunnel collapse, evaluation method of theoretical stability of tunnel, classification of the accident types and recovery method, measure of accident and important functions, collapse of mine in weak band and a surface of discontinuity, collapse of dent in mine head, collapse in shallow tunnel and valley, case of collapse in weak ground and analysis of tunnel collapse cases.
[en] Supervision is a common instrument for controlling constructions of tunnels. In order to suit relevant project’s purposes a supervision procedure is modified by local conditions, habits, codes and ways of allocating of a particular tunnelling project. The duties of tunnel supervision are specified in an agreement with the client and they can include a wide range of activities. On large scale tunnelling projects the supervision tasks are performed by a high number of people of different professions. Teamwork, smooth communication and coordination are required in order to successfully fulfil supervision tasks. The efficiency and quality of tunnel supervision work are enhanced when specialized software applications are used. Such applications should allow on-line data management and the prompt evaluation, reporting and sharing of relevant construction information and other aspects. The client is provided with an as-built database that contains all the relevant information related to a construction process, which is a valuable tool for the claim management as well as for the evaluation of structure defects that can occur in the future. As a result, the level of risks related to tunnel constructions is decreased. (paper)
[en] In this contribution the Bayesian statistical method is applied to assess the expected probability distribution of the terrain subsidence in the course of tunnel excavation. The approach utilizes a number of simplifying assumptions regarding the system kinematics to arrive at a very simple model with just a few degrees of freedom. This deterministic model together with the intrinsic uncertainties of its parameters and measurement inaccuracies are used to formulate the stochastic model which defines a distribution of the predicted values of terrain subsidence. Assuming the measured data to be fixed, the stochastic model thus defines the likelihood function of the model parameters which is directly used for updating their prior distribution. This way the model parameters can be incrementally updated with each excavation step and the prediction of the model refined. (paper)
[en] Tunneling in densely populated urban areas frequently brings about under-crossing the existing tunnels, which may induce serviceability problems to the existing tunnels. In order to obtain accurate prediction of ground settlement, the current study synthetically analyzes the coupling effects of new tunnels, in-between soil and the existing tunnel, and proposes a new method for predicting the ground settlement caused by construction of a new subway twin tunnel under-passing an existing tunnel. This paper classifies the influence zone caused by construction of the twin tunnels under-passing existing tunnel into strong, weak and no influence zones based on synthetically considering the coupling effects of front-tunnel, in-between soil, rear-tunnel, and the existing tunnel. Further, by extending the proposed method and applying it to the case of twin-tunneling under-crossing an existing tunnel, detail processes for predicting the ground settlement are presented for the cases of strong and weak influence zones. Two case studies were carried out to verify the proposed method, and the results show that the predicting settlements well agree with the measured data.
[en] To participate in social impact assessments, members of a community need to understand both the nature and complexity of impacts at the individual and social level. This study considers the role of engagement in developing community understanding of social impacts by documenting and analyzing organizational and community actions and responses in the Adani Carmichael mine case. Findings suggest engagement facilitates the conduct of social churn. We define social churn as a process of collective level discussion, meaning-making, and consensus-building from multiple information inputs in response to equivocality or uncertainty resulting from organizational behavior, out of which is generated an articulation of community level perceptions of that organizational behavior and its impacts at an individual, community, and societal level. Theoretically, the findings of this study challenge traditional linear notions of social impact assessments and offer an alternative engagement-based model. Practically, the model identifies ways in which organizations can recognize and participate in the social processes that both create and represent the differing levels of social reality determining perceptions of those impacts.
[en] Given the uncertainty in grade at a mine location, a financially risk-averse decision-maker may prefer to incorporate this uncertainty into the ore selection process. A FORTRAN program risksel is presented to calculate local risk-adjusted optimal ore selections using a negative exponential utility function and three dominance models: mean-variance, mean-downside risk, and stochastic dominance. All four methods are demonstrated in a grade control environment. In the case study, optimal selections range with the magnitude of financial risk that a decision-maker is prepared to accept. Except for the stochastic dominance method, the risk models reassign material from higher cost to lower cost processing options as the aversion to financial risk increases. The stochastic dominance model usually was unable to determine the optimal local selection