New drilling methods for the conductor casing operations

The necessity to apply casing to wells drilled in loose rock strata have recently created conditions for the modernization of old solutions and the development of new drilling technologies. The newest World's design and technological solutions for rotary, rotary-percussion and percussion drillings are presented in the paper with a further development directions indicated. An emphasis is put on the comparison of frequently diversified technologies basing on the concurrent drilling and the casing operations. In the course of an analysis of distribution of forces acting on the casing, the strength conditions were specified to enable a proper selection of physical properties and geometrical parameters of pipes. An exemplary calculation indicates that axial forces and torque have an influence on the selection of the outer diameter of casing made of various materials

Choosing the trenchless renovation methods and trenchless underground methods of pipelines refitting

The authors describe causes of carrier pipe ageing and methods of their inspection and renovation. The technical aspects of choosing the renovation methods are also presented. The paper includes a decision-making flowchart for choosing the carrier pipes renovation

Now-casting Romanian Migration into the United Kingdom by using Google Search engine data

Background: Short-term forecasts of international migration are often based on data that are incomplete, biased, and reported with delays. There is also a scarcity of migration forecasts based on combined traditional and new forms of data. Objective: This research assessed an inclusive approach of supplementing official migration statistics, typically reported with a delay, with the so-called big data from Google searches to produce short-term forecasts ("now-casts") of immigration flows from Romania to the United Kingdom. Methods: Google Trends data were used to create composite variables depicting the general interest of Romanians in migrating into the United Kingdom. These variables were then assessed as predictors and compared with benchmark results by using univariate time series models. Results: The proposed Google Trends indices related to employment and education, which exhaust all possible keywords and eliminate language bias, match trends observed in the migration statistics. They are also capable of moderate reductions in prediction errors. Conclusions: Google Trends data have some potential to indicate up-to-date current trends of interest in mobility, which may serve as useful predictors of sudden changes in migration. However, these data do not always improve the accuracy of forecasts. The usability of Google Trends is also limited to short-term migration forecasting and requires understanding of contexts surrounding origin and destination countries. Contribution: This work provides an example on combining Google Trends and official migration data to produce short-term forecasts, illustrated with flows from Romania to the UK. It also discusses caveats and suggests future work for using these data in migration forecasting

Integrated Modelling of European Migration: Background, specification and results

The aims of this paper are to present the background and specification of the Integrated Modelling of European Migration (IMEM) model. Currently, international migration data are collected by individual countries with separate collection systems and designs. This creates problems when attempting to understand or predict population movements between countries as the reported data are inconsistent in terms of their availability, definitions and quality. Rather than wait for countries to harmonise their migration data collection and reporting systems, we propose a model to overcome the limitations of the various data sources. In particular, we propose a Bayesian model for harmonising and correcting the inadequacies in the available data and for estimating the completely missing flows. The focus is on estimating recent international migration flows amongst countries in the European Union (EU) and European Free Trade Association (EFTA) from 2002 to 2008, using data collected by Eurostat and other national and international institutions. We also include additional information provided by experts on the effects of undercount, measurement and accuracy. The methodology is integrated and capable of providing a synthetic data base with measures of uncertainty for international migration flows and other model parameters.

Magnetic field sensor with voltage-tunable sensing properties

We report on a magnetic field sensor based on CoFeB/MgO/CoFeB magnetic tunnel junctions. By taking advantage of the perpendicular magnetic anisotropy of the CoFeB/MgO interface, the magnetization of the sensing layer is tilted out-of-plane which results in a linear response to in-plane magnetic fields. The application of a bias voltage across the MgO tunnel barrier of the field sensor affects the magnetic anisotropy and thereby its sensing properties. An increase of the maximum sensitivity and simultaneous decrease of the magnetic field operating range by a factor of two is measured. Based on these results, we propose a voltage-tunable sensor design that allows for active control of the sensitivity and the operating filed range with the strength and polarity of the applied bias voltage.Comment: 4 pages, 4 figures, lette

Migration Scenario Narratives

A considerable amount of literature has been published on global and migration scenarios in recent decades. Central to the migration scenarios and narratives are the concepts of migration drivers and migration dynamics. Demographic, economic, technological, social, political, and environmental developments and complex interrelations between these domains are considered essential in creating plausible future migration developments. This report provides a set of internally consistent and evidence-based qualitative scenario narratives.The narratives are built on consistent demographic, socio-economic, environmental and political alternate futures generated for the EU and developing countries based on the qualitative and quantitative evidence gathered in the FUME project. Each narrative describes the future for the EU and developing countries in the short-term until 2030 and in the long-term between 2030 and 2050. These alternative futures are complemented by the potential changes in the future migratory demand and pressure from the expert survey conducted in the project and the characteristics of future migrants from the Delphi survey.<br/

A groundwater flow model for the Wolin Island area, including glaciotectonic deformation

During the construction of mathematical models for mapping hydrogeological conditions it is necessary to apply sim- plifications, both in the geological structure and in hydrogeological parameters used. The present note discusses prob- lems surrounding the mapping of glaciotectonic disturbances that occur in the northern part of Wolin Island (northwest Poland). For this part of the island, a direct outflow of groundwater towards the Baltic Sea basin has been determined on the basis of geophysical survey results. An important feature in the hydrogeological conditions here is the isolation of groundwater from both the Baltic Sea and Szczecin Lagoon by clay with a Cretaceous xenolith. Such a geologi- cal structure explains the presence of perched water at considerable heights in zones close to the cliffs, without any significant hydraulic connection with surrounding reservoirs. Hydrogeological conditions of Wolin Island have been modelled using the Visual MODFLOW package v.4.2. In the vertical section, these conditions can be simplified to one aquifer (Pleistocene-Holocene), in which two aquifers can be distinguished. In a large part of the island, these remain in mutual hydraulic contact: layer I – upper, with an unconfined aquifer, and layer II – lower, with a confined aquifer, locally an unconfined one. The schematisation of hydrogeological conditions adopted here has allowed to reproduce present groundwater dynamics in the study area