93 research outputs found

    Professionally-Oriented Communicative Language Teaching Approach by the Design of a Computer Assisted ESP Course: Analysis of Results

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    Professionally-Oriented Communicative Language Teaching is an effective approach widely recognized among scientists and teachers which involves learners in authentic environment and communication and helps develop communicative competence of non-native speakers studying English for specific purposes (ESP). With the increase of Computer Assisted Language Learning teachers are constantly facing challenges to combine information technology with the Professionally-Oriented Communicative Language Teaching approach, and to develop and design relevant communicative activities which result in non-native speakers' of English improvement in communicative competence. The attempt to integrate computer assisted language environments and professionally oriented communicative language teaching results in the development of E-learning ESP courses in the Modular Object Oriented Developmental Learning Environment, based on the module "Electric systems and networks". The subjects of the study were sixty students, including students from Vietnam and the Czech Republic studying ESP at the Institute of Power Engineering of Tomsk Polytechnic University. The data was collected over a period of two years from the results of students' performance and a questionnaire survey concerning feedback on students' communicative language activities conducted during the course. The results indicate variations in the attitude of students from different countries to the developed communication activities. As the students state, however, the e-learning ESP course provides communicative situations similar to real ones and gives an opportunity to use the acquired knowledge in practical, professional, and research activity

    Accounting for the three-dimensional distribution of Escherichia coli concentrations in pond water in simulations of the microbial quality of water withdrawn for irrigation

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    Evaluating the microbial quality of irrigation water is essential for the prevention of foodborne illnesses. Generic Escherichia coli (E. coli) is used as an indicator organism to estimate the microbial quality of irrigation water. Monitoring E. coli concentrations in irrigation water sources is commonly performed using water samples taken from a single depth. Vertical gradients of E. coli concentrations are typically not measured or are ignored; however, E. coli concentrations in water bodies can be expected to have horizontal and vertical gradients. The objective of this work was to research 3D distributions of E. coli concentrations in an irrigation pond in Maryland and to estimate the dynamics of E. coli concentrations at the water intake during the irrigation event using hydrodynamic modeling in silico. The study pond is about 22 m wide and 200 m long, with an average depth of 1.5 m. Three transects sampled at 50-cm depth intervals, along with intensive nearshore sampling, were used to develop the initial concentration distribution for the application of the environmental fluid dynamic code (EFDC) model. An eight-hour irrigation event was simulated using on-site data on the wind speed and direction. Substantial vertical and horizontal variations in E. coli concentrations translated into temporally varying concentrations at the intake. Additional simulations showed that the E. coli concentrations at the intake reflect the 3D distribution of E. coli in the limited pond section close to the intake. The 3D sampling revealed E. coli concentration hot spots at different depths across the pond. Measured and simulated 3D E. coli concentrations provide improved insights into the expected microbial water quality of irrigation water compared with 1D or 2D representations of the spatial variability of the indicator concentration

    Filamentation of collimated Ti:sapphire-laser pulses in water

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    The results of experimental studies of the spatial characteristics of multiple filamentation terawatt femtosecond Ti:Salaser in water are presented. With an increase in initial power laser pulses increases the number of filaments, the length of the field is increased filamentation and reducing the length of the filaments have been shown. The distribution of the filaments in the longitudinal direction of the field of multiple filamentation has a maximum cross-sectional filament is shifted from the center to the periphery of the beam at the end region of filamentation. The minimum diameter of the beam on the track corresponds to the position of the maximum number of filaments. After the point of maximum impulse essentially loses energy in the initial direction of propagation. Upon reaching the pulse power 2 104 Pcr of multiple filamentation area is formed of a hollow cone, the apex directed to the radiation source

    Multiple filamentation Ti:Sapphire-laser pulses in water

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    The results of experimental studies of the spatial characteristics of multiple filamentation terawatt femtosecond Ti:Salaser in water are presented. With an increase in initial power laser pulses increases the number of filaments, the length of the field is increased filamentation and reducing the length of the filaments have been shown. The distribution of the filaments in the longitudinal direction of the field of multiple filamentation has a maximum cross-sectional filament is shifted from the center to the periphery of the beam at the end region of filamentation. The minimum diameter of the beam on the track corresponds to the position of the maximum number of filaments. After the point of maximum impulse essentially loses energy in the initial direction of propagation. Upon reaching the pulse power 2 104 Pcr of multiple filamentation area is formed of a hollow cone, the apex directed to the radiation source

    Localized high-intensity light structures during multiple filamentation of Ti:sapphire-laser femtosecond pulses along an air path

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    The results of experimental studies of the transverse structure of a laser beam after multiple filamentation are presented. A ring structure of radiation is formed around individual filaments in a beam cross section inside the multiple filamentation domain, and at a dozen meters from it a common ring structure starts forming surrounding postfilamentation light channels (PFC). It is shown that the spectra of the PFC, rings, and beam are significantly different. The ring spectrum broadens asymmetrically relative to the carrier wavelength and is mainly concentrated in the short wavelength region. The PFC spectrum has a significant and more symmetrical broadening and covers the range 630–1000 nm

    Filamentation of focused and collimated laser beams in liquids

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    Experimental results of investigations into the transformation of the spectral and spatial characteristics of femtosecond collimated and focused Ti:Sapphire-laser beams with wavelengths of 800 and 400 nm upon filamentation in continuous liquid media are presented. It is shown that broadening of the laser pulse spectrum due to phase self-modulation in the medium with a cubic nonlinearity depends on the pulse power and beam diameter. Dependences of the number of filaments, width of laser radiation spectrum, nonlinear focusing distance, and diameter of the filamentation region on the laser pulse power are measured. The existence of a relative power interval in which the explosive growth of the number of filaments occurs, is established. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

    Filamentation of collimated Ti:sapphire-laser pulses in the glass

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    The results of experiments to study the spatial characteristics of multiple filamentation gigawatt laser pulses in the glass are presented. It is shown that with increasing pulse power multiple filamentation region increases in length and diameter, the distribution of filaments within the region has a maximum value when the power > 105 Pcr area filamentation takes the form of a hollow cone, the apex directed to the source of the laser radiation
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