Photolithographic Mask Fabrication Process Using Cr/Sapphire Carriers

Elaboration of the technology of novel photolithographic masks fabricated on sapphire substrates for UV and DUV application was described. The main technological steps of mask fabrication as Cr metallization deposition, selection of resist for lithography and Cr layer etching were developed and reported. The etching of Cr films was carried out through resist mask. Detailed study of Cr layer etching process was performed using different solutions such as KMnO4, HCl and ceric ammonium nitrate-based solutions to obtain good-quality structures with the smallest possible undercut of Cr layer and smooth edge. The mask fabrication process was validated by fabrication of test structures of microelectronic device using photolithography technique

Cooperation needed indeed? : school leaders' opinions

Cooperation is crucial in educational context. Erikson says that ‘cooperation is the fundamental key of human development’ (Erikson, 2013, pp. 26-27). Schools are treated as institutions responsible for preparing young people to be self-regulated and responsible human beings able to cooperate for the sake of their own development (Mazurkiewicz, 2014). Head teachers as school leaders initiate and organize these processes. Sennett thinks that cooperation requires the competences, especially social competences - dialogical competences (listening well to each other, finding common views, conflict management etc.) (Sennett, 2013). The paper presents the results of research showing how school heads perceive their competencies that will be taken as a starting point for designing proposals of new type of training for school leaders in Poland. More than 2800 principals of different types of schools were asked to assess their competences in six broad areas. The research aim of this paper is to analyze the perception of cooperation by the principals. The research shows that competences related to cooperation are important for principals and they declare that they have them. We can conclude as well that cooperation with other entities is more important for principals of school located in smaller cities and in villages

Study of interface of ohmic contacts to AlGaN/GaN heterostructure

The paper embraces studies of the interface of ohmic contacts and AIIIBV-N heterostructure. The TiAl based metallization stack was investigated. The Ti/Al/Ni/Au contact to AlGaN/GaN heterostructures fabricated by metal-organic vapour phase epitaxy was examined using three methods i.e. etching of annealed contact metallization, fractures (prepared at room temperature and after a bath in liquid nitrogen) and microsections imaging. The main focus was on the estimation of reaction range on the metal-semiconductor interface of samples. In the first method, the surface of AlGaN/GaN heterostructure after etching of metallization was studied by an optical microscope, scanning electron microscope and atomic force microscope. The changes of surface morphology of heterostructure directly reflect solid state reactions range between metallization and semiconductor. The range of reactions was also observed using the small-angle microsections method while the fractures analysis did not bring valuable information

The significance of social context for student's learning process : the areas of exploration

Przedmiotem niniejszego artykułu jest poszukiwanie zmiennych środowiskowych, mających istotny wpływ na uczenie się uczniów. Autorka prezentuje fragmenty swoich badań, gdzie przedstawia opinię uczniów na temat istotności wyodrębnionych osi społecznych w szkole oraz identyfikuje obiecujące zależności pomiędzy zmiennymi, otwierające możliwości dalszej eksploracji jakościowej. Analiza wykazała, że uczniowie lubiący szkołę chętnie angażują się w życie klasy i szkoły oraz są aktywni w swoim środowisku. Zależności te zostały zweryfikowane jako istotne statystycznie.The main goal of this chapter is to explore and identify social variables that impact a students’s learning. The Author presents a piece of own research about student’s opinions of significance defined social axes and identifies promising correlations between variables that could be qualitatively explored. The data analysis indicates that students that like school are willing to be involved in the classroom and school and they are active in their social context as well. These correlations find out as statistical significant

Formation process and properties of ohmic contacts containing molybdenum to AlGaN/GaN heterostructures

Properties of wide bandgap semiconductors as chemical inertness to harsh conditions and possibility of working at high temperature ensure possible applications in the field as military, aerospace, automotive, engine monitoring, flame detection and solar UV detection. Requirements for ohmic contacts in semiconductor devices are determined by the proposed application. These contacts to AlGaN/GaN heterostructure for application as high temperature, high frequency and high power devices have to exhibit good surface morphology and low contact resistance. The latter is a crucial factor in limiting the development of high performance AlGaN/GaN devices. Lowering of the resistance is assured by rapid thermal annealing process. The paper present studies of Ti/Al/Mo/Au ohmic contacst annealed at temperature range from 825°C to 885°C in N2 atmosphere. The electrical parameters of examined samples as a function of the annealing process condition have been studied. Initially the annealing temperature increase caused lowering of the contacts resistance. The lowest value was noticed for the temperature of annealing equal to 885°C. Further increase of annealing temperature led to deterioration of contact resistance of investigated ohmic contacts

Expression of MUC1 mucin in human umbilical vein endothelial cells (HUVEC).

Mucin 1 (MUC1) is a membrane-bound glycoprotein that is expressed by various epithelial cell types. MUC1 functions include modulation of cell adhesion, signal transduction, lubrication and hydration of epithelial surfaces, and their protection from infection. In this study we demonstrated that MUC1 is expressed in human umbilical vein endothelial cells (HUVECs) and could be released/shed from cellular membrane. MUC1 presence in these cells was verified using three methods: Western blotting, flow cytometry and metabolic labeling. We also showed that mucin expression is stimulated by proinflammatory cytokines: about a 2-fold increase was observed after TNF-Îą treatment and lower after IFN-Îł alone and in combination with TNF-Îą treatment. It can be assumed that the presence of MUC1 in endothelial cells may have an important role in the interactions with different cell types in physiological and pathological processes

The Place of 3D Printing in the Manufacturing and Operational Process Based on the Industry 4.0 Structure

The article presents the place of 3D printing in the manufacturing and operational process. It analyzes selected incremental technologies in the product life cycle. It describes selected processes for testing the properties of materials used in 3D printing, including accelerated aging tests and simulation of operating conditions. Areas of application of 3D printing were defined, starting from design and prototype development through manufacturing of technological tools and finally finished products. Design criteria of additivelymanufactured elements in relation to the exploitation process are discussed. A methodology for the development of 3D-CAD models of manufactured elements, software processing of data and data storage format for manufacturing products and spare parts is presented. The assumptions of repair procedures based on the production of spare parts by means of 3D printing in relation to data circulation compatible with the idea of Industry 4.0 structure have been adopted

Synthesis and Characterization of Ga2O3 and In2O3 Nanowires

In this work, the thermal synthesis and characterization of gallium oxide and indium oxide nanowires using vapour-liquid-solid mechanism at atmospheric pressure were described. Au nanoislands formed by the solid-state dewetting process of various thickness metal layer were applied as growth catalyst of nanowires while high-purity metal reactants (In, Ga) were applied as AIII precursors. The catalytic layer thickness influence on the morphology of investigated nanostructures was studied. Material composition and structural properties were used for crystallographic quality of AIII-oxide nanowires examination

A pelagic microbiome (viruses to protists) from a small cup of seawater

The aquatic microbiome is composed of a multi-phylotype community of microbes, ranging from the numerically dominant viruses to the phylogenetically diverse unicellular phytoplankton. They influence key biogeochemical processes and form the base of marine food webs, becoming food for secondary consumers. Due to recent advances in next-generation sequencing, this previously overlooked component of our hydrosphere is starting to reveal its true diversity and biological complexity. We report here that 250 mL of seawater is sufficient to provide a comprehensive description of the microbial diversity in an oceanic environment. We found that there was a dominance of the order Caudovirales (59%), with the family Myoviridae being the most prevalent. The families Phycodnaviridae and Mimiviridae made up the remainder of pelagic double-stranded DNA (dsDNA) virome. Consistent with this analysis, the Cyanobacteria dominate (52%) the prokaryotic diversity. While the dinoflagellates and their endosymbionts, the superphylum Alveolata dominates (92%) the microbial eukaryotic diversity. A total of 834 prokaryotic, 346 eukaryotic and 254 unique virus phylotypes were recorded in this relatively small sample of water. We also provide evidence, through a metagenomic-barcoding comparative analysis, that viruses are the likely source of microbial environmental DNA (meDNA). This study opens the door to a more integrated approach to oceanographic sampling and data analysis