Attitude Markers in Media Representation of Latvia's Accession to the Eurozone

2014. gada 1. Janvārī Latvija pievienojās eirozonai un pieņēma eiro par valsts oficiālo valūtu. Liela daļa Latvijas iedzīvotāju sākotnēji bija pret jaunās valūtas ieviešanu un iestāšanās eirozonā izraisīja diskusijas starptautiskajā vidē - Dažas valstis atbalstīja valūtas maiņu un slavēja Latviju, citas skatījās uz valūtas ieviešanu negatīvi. Bakalaura darba tēma ir attieksmes markējuma noteikšana un analīze, ņemot vērā, ka tas ir viens no instrumentiem, kas ietekmē diskursa par Latvijas iestāšanos eirozonā komunikatīvās īpašības, kā arī attieksmes marķējuma reģionālās atšķirības noteikšana konkrētos reģionos - Kontinentālā Eiropa, Lielbritānija, ASV un Krievija. Pētījumā tiek izmantota aprakstoša analīze, kas apraksta konceptu un tā attiecīgās komponentes, kā arī skaidrojoša analīze, kas skaidro kā konkrētais koncepts strādā.Mediju tekstu korpuss tiek analizēts kvalitatīvi un kvantitatīvi. Bakalaura darba gaitā tika noskaidrots, ka Lielbritānijas mediju attieksme pret eiro ieviešanu Latvijā ir neitrāla, Eiropas – pozitīva, ASV un Krievijas – negatīva. Atslēgvārdi: Attieksme, eirozona, mediji, ziņas, attieksmes marķērjums, Eiropa, ASV, Lielbritānija, Krievija.On January 1st 2014, Latvia joined the Eurozone and accepted the Euro as the official currency of the country. Many citizens of Latvia were initially against the introduction of the new currency and thus, the joining of the Eurozone caused international discussions – some countries supported the change of the currency and praised Latvia, others viewed the move negatively. The goal of the Bachelor thesis is to determine and analyse the attitude markers as one of the devices that influence the communicative quality of discourse on Latvia’s accession to the Eurozone to see how the attitude markers would differ in the established regional media groups, i.e. continental Europe, the United Kingdom, Russia and the USA. The methods used in the thesis include descriptive research, which is used to describe some phenomenon or to record its characteristics as well as explanatory research, which explains how or why some phenomenon works. The selection of media texts is processed qualitatively and quantitatively. The research has shown that the attitude of the United Kingdom’s media was neutral, Europe’s – positive, the USA’s and Russia’s – negative. Keywords: attitude, Eurozone, media, news, attitude markers, Europe, USA, Great Britain, Russia

Two-Stage Mechanism of Nanocones Formation by Laser Radiation on a Surface of Elementary Semiconductors

Investigation of the mechanism of nanocones formation on the irradiated surface of Si and Ge has shown that this process is characterized by two stages – Laser Redistribution of Intrinsic Defects and Selective Laser Annealing. At the first stage of the process, formation of homojunction structure in crystal takes place due to generation and redistribution of intrinsic point defects in temperature gradient field, which causes strongly absorbed laser radiation. At the second stage, formation of nanocones on the irradiated surface of a semiconductor due to mechanical plastic deformation of the top layer enriched by interstitials and relaxation of the mechanical compressive stress arising between top layer and buried layer enriched by vacancies takes place. In experiments i-Ge single crystals with Na = 7.4 × 1011 cm-3, Nd = 6.8 × 1011 cm-3, where Na and Nd are acceptors’ and donors’ concentration, and p-Si(B) were used. Different intensities and wavelength of nanosecond Nd:YAG laser with pulse duration were used to irradiate the samples. The evidences of these stages will be presented by experimental investigation on p-Si and i-Ge crystals irradiated by Nd:YAG laser radiation using following methods: microhardness, photoluminescence, Raman back scattering atomic force microscopy and Current-Voltage characteristics

Mechanism of P-n Junction Formation in Intrinsic Semiconductor by Laser Radiation

I. INTRODUCTION P-n junction is the most important component of many semiconductor devices. Thermodiffusion, ion implantation and molecular beam epitaxy are only a few methods to form a p-n junction. The main drawback for these methods is high cost of equipment. Therefore this equipment is not available for small and medium companies. A possibility of p-n junction formation by laser radiation was shown in several semiconductors: p-Si, p-CdTe, p-InSb, p-InAs, p-PbSe and p- Ge. Different mechanisms have been proposed to explain the nature of inversion of conductivity type: impurities’ segregation, defects’ generation, amorphization and oxygen related donor generation. However, the proposed mechanisms have many flaws and even contradictions; therefore the mechanism of p-n junction formation by laser radiation (LR) is not clear until now. The aim of the work is to show a new possibility of p-n junction formation in intrinsic elementary semiconductor by LR without any impurities and to propose the new mechanism of p-n junction formation. II. RESULTS AND DISCUSSION We assume that, the intrinsic defects play the main role in formation of p-n junction. For this reason i-Ge crystal was irradiated by Nd:YAG laser with different energy of quantum. In experiments i-Ge single crystals with NA = 7.4 × 1011 cm-3 and ND = 6.8 × 1011 cm-3 s were used. Samples were prepared by mechanical polishing with diamond grease followed by chemical treatment with CP-4 etching solution. To form a p-n junction, nanosecond Nd:YAG laser with wavelengths λ1 = 1064 nm, λ2= 532 nm and λ3= 266 was used. Measurements of I-V characteristics were done by soldering 99% Sn and 1% Sb alloy electrical contacts directly on the irradiated surface of i- Ge and the opposite side. I-V characteristics of i-Ge samples before and after irradiation different intensities of Nd:YAG laser with wavelength 266 nm and different laser intensities are shown in Fig.1. Increase of rectification ratio (RR) of I-V characteristics with intensity of the laser radiation, energy of laser radiation quanta and numbers of pulses were observed in this experiment (see Fig.2). Moreover, this process takes place in threshold manner, it means, RR is non-monotonic function on laser radiation intensity. These results are explained by damage of p-n junction at threshold intensity (Ith) due to formation of nanocones.The mechanism of this phenomenon is explained by generation and redistribution of intrinsic point defects in temperature gradient field, which causes strongly absorbed LR. The redistribution of defects takes place because interstitial atoms drift towards the irradiated surface, but vacancies drift in the opposite direction – in the bulk of semiconductor according to Thermogradient effect [1]. Since interstitials in Ge crystal are of n-type and vacancies are known to be of p-type [2], a p-n junction is formed. III. CONCLUSIONS For the first time we have proved that the mechanism of pn junction formation in semiconductor is caused by generation and redistribution of intrinsic point defects in temperature gradient field induced by LR. Increase of rectification ratio of p-n junction with the increase of LR intensity is typical for Thermogradient effect; therefore this effect has the main role in p-n junction formation. IV. REFERENCES [1] A. Medvid: Redistribution of Point Defects in the Crystalline Lattice of a Semiconductor in an Inhomogeneous Temperature Field, Defect and Diffusion Forum , 2002, 210-212: 89-102. [2] Cor Claeys: Germanium-based technologies: from materials to devices. London Elsevier B.V. 2007 Acknowledgment: The author gratefully acknowledges financial support in part by the European Regional Development Fund within the project “Sol-gel and laser technologies for the development of nanostructures and barrier structures» No 2010/0221/2DP/2.1.1.1.0/10/APIA/VIAA/14

Two-Stage Model of Nanocones Formation on a Surface of Elementary Semiconductors by Laser Radiation

In this work we study mechanism of nanocone formation on a surface of elementary semiconductors by Nd:YAG laser radiation. Our previous investigations of SiGe and CdZnTe solid solutions have shown that nanocone formation mechanism is characterized by two stages. The first stage is characterized by formation of heterostructure. For example, Ge/Si heterostructure from SiGe solid solutions, and the second stage is characterized by formation of nanocones by mechanical plastic deformation of the compressed Ge layer on Si due to mismatch of Si and Ge crystalline lattice. The mechanism of nanocone formation for elementary semiconductors is not clear until now. Therefore, the main goal of our investigations is to study the stages of nanocone formation in elementary semiconductors. A new mechanism of p-n junction formation by laser radiation in the elementary semiconductor as a first stage of nanocones formation is proposed. We explain this effect by following way: p-n junction is formed by generation and redistribution of intrinsic point defects in temperature gradient field - the Thermogradient effect, which is caused by strongly absorbed laser radiation. According to the Thermogradient effect, interstitial atoms drift towards the irradiated surface, but vacancies drift to the opposite direction - in the bulk of semiconductor. Since interstitials in Ge crystal are of n-type and vacancies are known to be of p-type, a n-p junction is formed. The mechanism is confirmed by appearance of diode-like current-voltage characteristics after i-Ge irradiation crystal by laser radiation. In Si mechanism is confirmed by conductivity type inversion and increased microhardness of Si crystal. The second stage of nanocone formation is laser heating up of top layer enriched by interstitial atoms with its further plastic deformation due to compressive stress caused by interstitials in the top layer and vacancies in the buried layer. © 2012 Medvid et al.; licensee Springer

Two-Stage Mechanism of Nanocones Formation by Laser Radiation on a Surface of Elementary Semiconductors

: Investigation of the mechanism of nanocones formation on the irradiated surface of Si and Ge has shown that this process is characterized by two stages – Laser Redistribution of Intrinsic Defects and Selective Laser Annealing. At the first stage of the process, formation of homojunction structure in crystal takes place due to generation and redistribution of intrinsic point defects in temperature gradient field, which causes strongly absorbed laser radiation. At the second stage, formation of nanocones on the irradiated surface of a semiconductor due to mechanical plastic deformation of the top layer enriched by interstitials and relaxation of the mechanical compressive stress arising between top layer and buried layer enriched by vacancies takes place. In experiments i-Ge single crystals with Na = 7.4 × 10^11 cm-3, Nd = 6.8 × 10^11 cm-3, where Na and Nd are acceptors’ and donors’ concentration, and p-Si(B) were used. Different intensities and wavelength of nanosecond Nd:YAG laser with pulse duration were used to irradiate the samples. The evidences of these stages will be presented by experimental investigation on p-Si and i-Ge crystals irradiated by Nd:YAG laser radiation using following methods: microhardness, photoluminescence, Raman back scattering atomic force microscopy and Current-Voltage characteristics

P-n Junction in Intrinsic Semiconductor Formed by Laser Radiation

P-n junction is the most important component of many semiconductor devices. Thermodiffusion, ion implantation and molecular beam epitaxy are only a few methods to form a p-n junction. The main drawback for these methods is high cost per p-n junction. A possibility of p-n junction formation by laser radiation was shown in several semiconductors: p-Si[1,2], p-CdTe[3], p-InSb[4,5], p-InAs[6], p-PbSe[7] and p-Ge[8]. Different mechanisms have been proposed to explain the nature of inversion of conductivity type: impurities’ segregation, defects’ generation, amorphization and oxygen related donor generation. However, the proposed mechanisms have many lacks and even contradictions; therefore the mechanism of p-n junction formation by laser radiation is not clear until now. For the understanding it, i-Ge crystal was irradiated by Nd:YAG laser with different energy of quantum. The crystal was used in the experiments as a model material because the concentration of impurities in this material is lower than the concentration of intrinsic point defects at RT. Increase of rectification ratio of I-V characteristics and barrier height with intensity of the laser radiation, energy of laser radiation quanta and numbers of pulses were observed in this experiment. The mechanism of this phenomenon is explained by generation and redistribution of intrinsic point defects in temperature gradient field, which causes strongly absorbed laser radiation. The redistribution of defects takes place because interstitial atoms drift towards the irradiated surface, but vacancies drift in the opposite direction – in the bulk of semiconductor according to Thermogradient effect. Since interstitials in Ge crystal are of n-type and vacancies are known to be of p-type, a p-n junction is formed. References 1. Y. Mada et al. Appl. Phys. Lett., 48, 1205 (1986). 2. J. Blums et al. Physics Status Solidi (a), K91, (1995). 3. A. Medvid’ et al., Radiat. Meas., 33, 725 (2001). 4. I. Fujisawa, Jap., J. Appl. Phys, 19, 2137 (1980). 5. A. Medvid‘ et al. Vacuum, 51, 245 (1998). 6. L. Kurbatov et al. Reports of Acad. Sc.USSR, 268, 594 (1983) 7. K.D. Tovstyuk et al. Ukrainian Journal of Physics, 21, 1918 (1984). 8. S.G. Kiyak et al. Physics and Technics of Semiconductors, 18, 1958 (1984)

Formation of p-n Junction in Intrinsic Semiconductor by Laser Radiation

P-n junction is the main component of many semiconductor devices. Thermodiffusion, ion implantation and molecular beam epitaxy are only a few methods to form a p-n junction. The main drawback for these methods is high cost per p-n junction since the equipment for these methods is expensive. A possibility of p-n junction formation by laser radiation was shown in several p- and n-type semiconductors: p-Si[1,2], p-CdTe[3], p-InSb[4,5], p-InAs[6], p-PbSe[7] and p-Ge[8] due to inversion of conductivity type. Different mechanisms have been proposed to explain the nature of inversion of conductivity type, for example, impurities' segregation, defects' generation, amorphization and oxygen related donor generation. However, the proposed mechanisms have many lacks and even contradictions, therefore the mechanism of p-n junction formation by laser radiation is not clear until now. For this purpose i-Ge crystal was irradiated by Nd:YAG laser with different energy of quantum. I-type Ge crystal was used in the experiments as a model material because the concentration of impurities in this material is lower than the concentration of intrinsic point defects at room temperature. Rectification effect of current-voltage characteristic in pure intrinsic Ge crystal after irradiation by Nd:YAG laser was observed. The effect is characterised by threshold intensity of the laser radiation. Increase of rectification ratio of current-voltage characteristics and barrier height with intensity of the laser radiation, energy of laser radiation quanta and number of pulses was observed in this experiment. The mechanism of this phenomenon is explained by generation and redistribution of intrinsic point defects in temperature gradient field, which causes strongly absorbed laser radiation. The redistribution of defects takes place because interstitial atoms drift towards the irradiated surface, but vacancies drift in the opposite direction * in the bulk of semiconductor according to Thermogradient effect. Since interstitials in Ge crystal are of n-type and vacancies are known to be of p-type, a p-n junction is formed

Organ-On-A-Chip (OOC) Image Dataset for Machine Learning and Tissue Model Evaluation

Organ-on-a-chip (OOC) technology has emerged as a groundbreaking approach for emulating the physiological environment, revolutionizing biomedical research, drug development, and personalized medicine. OOC platforms offer more physiologically relevant microenvironments, enabling real-time monitoring of tissue, to develop functional tissue models. Imaging methods are the most common approach for daily monitoring of tissue development. Image-based machine learning serves as a valuable tool for enhancing and monitoring OOC models in real-time. This involves the classification of images generated through microscopy contributing to the refinement of model performance. This paper presents an image dataset, containing cell images generated from OOC setup with different cell types. There are 3072 images generated by an automated brightfield microscopy setup. For some images, parameters such as cell type, seeding density, time after seeding and flow rate are provided. These parameters along with predefined criteria can contribute to the evaluation of image quality and identification of potential artifacts. This dataset can be used as a basis for training machine learning classifiers for automated data analysis generated from an OOC setup providing more reliable tissue models, automated decision-making processes within the OOC framework and efficient research in the future