While the existing literature focuses on analyzing individual hedges and comparing their use by native and non-native speakers, little attention has been paid to the teaching of conversational hedges. Research reveals that despite their pervasive nature in spoken discourse, hedges are regarded by teachers as ‘verbal garbage’ (Schiffrin 1987), not worthy of teaching. The aim of this study is to investigate college teachers’ perceptions of hedging devices in spoken discourse as well as their attitudes to the teaching of hedges. A questionnaire was administered to elicit the teachers’ responses. The results indicate that college teachers are aware of the significance and usefulness of hedges in spoken discourse; nevertheless, they have doubts about the value of teaching them. The paper will conclude with a discussion of the pedagogical implications of these findings.
In view of the world’s recent changes in the mineral market, it is becoming increasingly important to ensure the sustainable and secure supply of raw materials, both within the European Union and in other high-developed countries. In response to this global challenge, as part of the European Commission’s Horizon 2020 Program for Research & Innovation, the 36-month INTRAW project was launched in February 2015 to foster international cooperation on raw materials. The EU-funded INTRAW project was set up to map and develop new cooperation opportunities related to raw materials between the EU and other technologically advanced countries, such as: Australia, Canada, Japan, South Africa and the United States. The first stage of the project was a review of conditions for the stable supply of raw materials from primary and secondary sources in selected countries: the United States, Canada, Australia, South Africa and Japan. The results of the work are two groups of comprehensive reports. The first of these is a broad contextual analysis of geological, environmental, political, technical -economic and social factors conducive to the effective management of mineral resources. The second group is operational reports, carried out in three thematic blocks: industry and trade, research and innovation, education. The analysis clearly shows that the basis for effective action in this area is a stable political, economic and institutional environment, which is friendly to mining and new entities wishing to invest in modern technologies, the exploration and exploitation of deposits. Investors are encouraged by tax regulations, sometimes also by direct government financial support and efficient licensing procedures. The well-defined protection of property rights, also for deposits is equally important. Selected aspects of a wide analysis of determinants of competitiveness for these countries were presented in the article below.
Mechanical components and tools in modern industry are facing increasing performance requirements leading to the growing need for advanced materials and thus, for modern frictional systems. In the last decades, the Pulsed Laser Deposition (PLD) has emerged as an unique tool to grow high quality mono- as well as multilayers surfaces in metallic/ceramic systems. Building up a knowledge base of tribological properties of industrially-scaled, room temperature deposited PLD hard coatings are the most important step for the application of these coatings in engineering design. Although single-layer coatings find a range of applications, there are an increasing number of applications where the properties of a single material are not sufficient. One way to surmount this problem is to use a multilayer coating. Application of metallic interlayers improves adhesion of nitride hard layer in multilayer systems, which has been used in PVD processes for many years, however, the PLD technique gives new possibilities to produce system comprising many bilayers at room temperature. Tribological coatings consisted of 2, 4 and 16 bilayers of Cr/CrN and Ti/TiN type were fabricated with the Pulsed Laser Deposition (PLD) technique in the presented work. It is found in transmission electron examinations on thin foils prepared from cross-section that both nitride-based multilayer structures studied are characterized by small columnar crystallite sizes and high defect density, what might rise their hardness but compromise coating adhesion. The intermediate metallic layers contained larger sized and less defective columnar structure compared to the nitride layers, which should improve the coatings toughness. Switching from single layer to multi-layer metal/nitride composition improved resistance to delamination.
Boron nitride thin layers were produced by means of the pulsed laser deposition technique from hexagonal boron nitride target. Two types of laser i.e. Nd:YAG with Q-switch as well as KrF coupled with RF generator were used. Influence of deposition parameters on surface morphology, phase composition as well as mechanical properties is discussed. Results obtained using Fourier Transformed Infrared Spectroscopy, Transmission and Scanning Electron Microscopy, Atomic Force Microscopy are presented. Micromechanical properties measured during microindentation, scratch and wear tests are also shown.
Pulsed laser deposition technique was applied for covering elastic cast-polyurethane membranes with titanium nitride and boron nitride layers. The deposition process was realized using a Nd:YAG laser with Qswitch in stages; firstly the membranes were coated with ultra-thin titanium nitride layer (TixN) by evaporation of a metallic titanium disk in nitrogen gas atmosphere and then a layer of boron nitride (BN) was deposited by ablation of hexagonal h-BN target in argon atmosphere. The surface morphology was observed by scanning electron microscopy. Chemical composition was analyzed by energy dispersive X-ray spectrometry. The phase analysis was performed by means of grazing incidence X-ray diffraction and attenuated total reflection infrared spectroscopy. The crystallographic texture was measured. The wear test was performed by pin-on-disk method. Hexagonal boron nitride layers with (0001)[uvtw] texture with flake-like grains were fabricated. The structure and texture of boron nitride was identical irrespectively of substrate roughness or BN thickness. Pin-on-disk wear tests showed that the coatings effectively decreased the friction coefficient from two to even four times comparing to pure polyurethane and polyurethane covered with graphite. This proved that deposited layers can replace graphite as a lubricating material used to protect polymer surfaces.