The XXL Survey XI: ATCA 2.1 GHz continuum observations

We present 2.1 GHz imaging with the Australia Telescope Compact Array (ATCA) of a 6.5 deg^2 region within the XXM-Newton XXL South field using a band of 1.1-3.1 GHz. We achieve an angular resolution of 4.7" x 4.2" in the final radio continuum map with a median rms noise level of 50 uJy/beam. We identify 1389 radio sources in the field with peak S/N >=5 and present the catalogue of observed parameters. We find that 305 sources are resolved, of which 77 consist of multiple radio components. These number counts are in agreement with those found for the COSMOS-VLA 1.4 GHz survey. We derive spectral indices by a comparison with the Sydney University Molongolo Sky Survey (SUMSS) 843MHz data. We find an average spectral index of -0.78 and a scatter of 0.28, in line with expectations. This pilot survey was conducted in preparation for a larger ATCA program to observe the full 25 deg^2 southern XXL field. When complete, the survey will provide a unique resource of sensitive, wide-field radio continuum imaging with complementary X-ray data in the field. This will facilitate studies of the physical mechanisms of radio-loud and radio-quiet AGNs and galaxy clusters, and the role they play in galaxy evolution. The source catalogue is publicly available online via the XXL Master Catalogue browser and the Centre de Donn\'ees astronomiques de Strasbourg (CDS).Comment: 7 pages, 6 figures. Accepted by A&A 13th October 201

Sensing Properties of Oxidized Nanostructured Silicon Surface on Vaporized Molecules

Porous silicon has been intensely studied for the past several decades and its applications were found in photovoltaics, biomedicine, and sensors. An important aspect for sensing devices is their long–term stability. One of the more prominent changes that occur with porous silicon as it is exposed to atmosphere is oxidation. In this work we study the influence of oxidation on the sensing properties of porous silicon. Porous silicon layers were prepared by electrochemical etching and oxidized in a tube furnace. We observed that electrical resistance of oxidized samples rises in response to the increasing ambient concentration of organic vapours and ammonia gas. Furthermore, we note the sensitivity is dependent on the oxygen treatment of the porous layer. This indicates that porous silicon has a potential use in sensing of organic vapours and ammonia gas when covered with an oxide layer

Solid-State Dispersions of Platinum in the SnO2 and Fe2O3 Nanomaterials

The dispersion of platinum (Pt) on metal oxide supports is important for catalytic and gas sensing applications. In this work, we used mechanochemical dispersion and compatible Fe(II) acetate, Sn(II) acetate and Pt(II) acetylacetonate powders to better disperse Pt in Fe2O3 and SnO2. The dispersion of platinum in SnO2 is significantly different from the dispersion of Pt over Fe2O3. Electron microscopy has shown that the elements Sn, O and Pt are homogeneously dispersed in α-SnO2 (cassiterite), indicating the formation of a (Pt, Sn)O2 solid solution. In contrast, platinum is dispersed in α-Fe2O3 (hematite) mainly in the form of isolated Pt nanoparticles despite the oxidative conditions during annealing. The size of the dispersed Pt nanoparticles over α- Fe2O3 can be controlled by changing the experimental conditions and is set to 2.2, 1.2 and 0.8 nm. The rather different Pt dispersion in α- SnO2 and α-Fe2O3 is due to the fact that Pt4+ can be stabilized in the α-SnO2 structure by replacing Sn4+ with Pt4+ in the crystal lattice, while the substitution of Fe3+ with Pt4+ is unfavorable and Pt4+ is mainly expelled from the lattice at the surface of α-Fe2O3 to form isolated platinum nanoparticles

Sensing properties of functionalized nanostructured silicon

Jedna od glavnih tema istraživanja u modernoj senzorici obuhvaća funkcionalizaciju nanostrukturiranih materijala u svrhu poboljšanja osjetljivosti i selektivnosti senzora. Eksperimentalni put prema unapređenju senzora uključuje izradu i karakterizaciju materijala velike specifične površine, njihovo tretiranje fizikalnim i kemijskim metodama, te ispitivanje njihovog odziva na pokusne agense. Doktorski rad će biti baziran na izradi nanostrukturiranog silicija, s naglaskom na porozni silicij dobiven elektrokemijskim jetkanjem. Fokus ovog rada je ispitati njegova senzorska svojstva, primarno spram para organskih otapala i plinova, te utjecaj funkcionalizacije kisikom na odziv takvog senzora.One of the main research topics in modern sensorics includes functionalisation of nanostructured materials with a goal of improving sensors’ sensitivity and selectivity. The experimental path leading to such improvement involves production and characterisation of materials with a large specific surface area, their physical and chemical treatment, and assessment of their response to test chemicals. The work of this thesis will be based on production of nanostructured silicon, with emphasis on porous silicon obtained by electrochemical etching. Focus of the thesis will be to explore the sensing properties of nanostructured silicon, primarily with respect to organic vapours and gases. Also, the effects of functionalisation and morphological characteristics on the sensor’s response will be studied

Sensing properties of functionalized nanostructured silicon

Jedna od glavnih tema istraživanja u modernoj senzorici obuhvaća funkcionalizaciju nanostrukturiranih materijala u svrhu poboljšanja osjetljivosti i selektivnosti senzora. Eksperimentalni put prema unapređenju senzora uključuje izradu i karakterizaciju materijala velike specifične površine, njihovo tretiranje fizikalnim i kemijskim metodama, te ispitivanje njihovog odziva na pokusne agense. Doktorski rad će biti baziran na izradi nanostrukturiranog silicija, s naglaskom na porozni silicij dobiven elektrokemijskim jetkanjem. Fokus ovog rada je ispitati njegova senzorska svojstva, primarno spram para organskih otapala i plinova, te utjecaj funkcionalizacije kisikom na odziv takvog senzora.One of the main research topics in modern sensorics includes functionalisation of nanostructured materials with a goal of improving sensors’ sensitivity and selectivity. The experimental path leading to such improvement involves production and characterisation of materials with a large specific surface area, their physical and chemical treatment, and assessment of their response to test chemicals. The work of this thesis will be based on production of nanostructured silicon, with emphasis on porous silicon obtained by electrochemical etching. Focus of the thesis will be to explore the sensing properties of nanostructured silicon, primarily with respect to organic vapours and gases. Also, the effects of functionalisation and morphological characteristics on the sensor’s response will be studied

Crisis management in public sector of Republic of Croatia

Promjena je neizostavna pojava sve dok postojimo. I to je tako oduvijek. Danas se promjene događaju sve češće i intenzivnije, pa se zbog toga suočavamo s ponavljajućim problemima, a kako sve više i više međusobno ovisimo o drugim ljudima, tuđi problemi uskoro postaju i naši problemi. Oni pak problemi koje ne rješavamo odmah po nastanku, postaju potencijalne krize. Upravo je pojam krize detaljno analiziran u ovom diplomskom radu kao i ono što ju uzrokuje. Cilj rada je dati pregled sustavne i praktične metode prepoznavanja uzroka krize koji bi se mogli odnositi posebice na javni sektor. Kriza ima golem učinak na čitavu organizaciju koja u određenim situacijama može dovesti do propasti. Kako bi se najprije ustanovio uzrok krize, rukovoditelji organizacije koju je zadesila kriza, moraju reagirati brzo kako bi spriječili njezin daljnji razvoj, a ukoliko do nje dođe, uz najmanju štetu ju i riješili. Važnost kriznog menadžmenta je istaknut u ovom radu te on čini dio šireg sustava organizacijskog upravljanja. Na temelju analizirane literature i znanstvenih radova, lako je pretpostaviti kako je neuobičajeno mala zastupljenost kriznog menadžmenta unutar poduzeća, bilo to javnih ili privatnih. Isti je set vrijednosti koje ta poduzeća posjeduju, polazeći od etničkih normi ponašanja, težnje za uspostavljanjem visokih zahtjeva profesionalizma i želje za čvrstom organizacijskom kulturom. Ni javna poduzeća ne mogu izbjeći podvrgavanju izazovima na tržištu te se ovisno o vrsti posla, i sama susreću s krizama. Instrumenti metoda kriznog menadžmenta i kriznog komuniciranja nisu u dovoljnoj mjeri primijenjeni niti u javnom sektoru Republike Hrvatske što ukazuje na nedovoljnu pripremljenost za potencijalne poslovne krize.Change is an inevitable phenomenon as long as we exist. And it has always been so. Today, changes are happening more and more often and intensely, so we are facing recurring problems, and as we become more and more dependent on other people, other people's problems soon become our problems. Those problems that we do not solve immediately after they arise become potential crises. It is the notion of crisis that is analyzed in detail in this thesis, as well as what causes it. The aim of this paper is to provide an overview of systematic and practical methods of identifying the causes of the crisis that could be related in particular to the public sector. The crisis has a huge impact on the entire organization, which in certain situations can lead to failure. In order to first determine the cause of the crisis, the leaders of the organization affected by the crisis must react quickly to prevent its further development and, if it occurs, to solve it with the least damage. The importance of crisis management is highlighted in this paper, and it forms part of a broader system of organizational management. Based on the analyzed literature and scientific papers, it is easy to assume that there is an unusually low representation of crisis management within Croatian companies, whether public or private. It is the same set of values that these companies possess, starting from ethnic norms of behavior, striving to establish high standards of professionalism and the desire for a solid organizational culture. Even public companies cannot avoid being exposed to market challenges, and depending on the type of work they do, they themselves face crises. The instruments of crisis management and crisis communication methods have not been sufficiently applied in the public sector of the Republic of Croatia, which indicates insufficient preparedness for potential business crises

Crisis management in public sector of Republic of Croatia

Promjena je neizostavna pojava sve dok postojimo. I to je tako oduvijek. Danas se promjene događaju sve češće i intenzivnije, pa se zbog toga suočavamo s ponavljajućim problemima, a kako sve više i više međusobno ovisimo o drugim ljudima, tuđi problemi uskoro postaju i naši problemi. Oni pak problemi koje ne rješavamo odmah po nastanku, postaju potencijalne krize. Upravo je pojam krize detaljno analiziran u ovom diplomskom radu kao i ono što ju uzrokuje. Cilj rada je dati pregled sustavne i praktične metode prepoznavanja uzroka krize koji bi se mogli odnositi posebice na javni sektor. Kriza ima golem učinak na čitavu organizaciju koja u određenim situacijama može dovesti do propasti. Kako bi se najprije ustanovio uzrok krize, rukovoditelji organizacije koju je zadesila kriza, moraju reagirati brzo kako bi spriječili njezin daljnji razvoj, a ukoliko do nje dođe, uz najmanju štetu ju i riješili. Važnost kriznog menadžmenta je istaknut u ovom radu te on čini dio šireg sustava organizacijskog upravljanja. Na temelju analizirane literature i znanstvenih radova, lako je pretpostaviti kako je neuobičajeno mala zastupljenost kriznog menadžmenta unutar poduzeća, bilo to javnih ili privatnih. Isti je set vrijednosti koje ta poduzeća posjeduju, polazeći od etničkih normi ponašanja, težnje za uspostavljanjem visokih zahtjeva profesionalizma i želje za čvrstom organizacijskom kulturom. Ni javna poduzeća ne mogu izbjeći podvrgavanju izazovima na tržištu te se ovisno o vrsti posla, i sama susreću s krizama. Instrumenti metoda kriznog menadžmenta i kriznog komuniciranja nisu u dovoljnoj mjeri primijenjeni niti u javnom sektoru Republike Hrvatske što ukazuje na nedovoljnu pripremljenost za potencijalne poslovne krize.Change is an inevitable phenomenon as long as we exist. And it has always been so. Today, changes are happening more and more often and intensely, so we are facing recurring problems, and as we become more and more dependent on other people, other people's problems soon become our problems. Those problems that we do not solve immediately after they arise become potential crises. It is the notion of crisis that is analyzed in detail in this thesis, as well as what causes it. The aim of this paper is to provide an overview of systematic and practical methods of identifying the causes of the crisis that could be related in particular to the public sector. The crisis has a huge impact on the entire organization, which in certain situations can lead to failure. In order to first determine the cause of the crisis, the leaders of the organization affected by the crisis must react quickly to prevent its further development and, if it occurs, to solve it with the least damage. The importance of crisis management is highlighted in this paper, and it forms part of a broader system of organizational management. Based on the analyzed literature and scientific papers, it is easy to assume that there is an unusually low representation of crisis management within Croatian companies, whether public or private. It is the same set of values that these companies possess, starting from ethnic norms of behavior, striving to establish high standards of professionalism and the desire for a solid organizational culture. Even public companies cannot avoid being exposed to market challenges, and depending on the type of work they do, they themselves face crises. The instruments of crisis management and crisis communication methods have not been sufficiently applied in the public sector of the Republic of Croatia, which indicates insufficient preparedness for potential business crises

Sensing properties of functionalized nanostructured silicon

Jedna od glavnih tema istraživanja u modernoj senzorici obuhvaća funkcionalizaciju nanostrukturiranih materijala u svrhu poboljšanja osjetljivosti i selektivnosti senzora. Eksperimentalni put prema unapređenju senzora uključuje izradu i karakterizaciju materijala velike specifične površine, njihovo tretiranje fizikalnim i kemijskim metodama, te ispitivanje njihovog odziva na pokusne agense. Doktorski rad će biti baziran na izradi nanostrukturiranog silicija, s naglaskom na porozni silicij dobiven elektrokemijskim jetkanjem. Fokus ovog rada je ispitati njegova senzorska svojstva, primarno spram para organskih otapala i plinova, te utjecaj funkcionalizacije kisikom na odziv takvog senzora.One of the main research topics in modern sensorics includes functionalisation of nanostructured materials with a goal of improving sensors’ sensitivity and selectivity. The experimental path leading to such improvement involves production and characterisation of materials with a large specific surface area, their physical and chemical treatment, and assessment of their response to test chemicals. The work of this thesis will be based on production of nanostructured silicon, with emphasis on porous silicon obtained by electrochemical etching. Focus of the thesis will be to explore the sensing properties of nanostructured silicon, primarily with respect to organic vapours and gases. Also, the effects of functionalisation and morphological characteristics on the sensor’s response will be studied

Effects of Thermal Oxidation on Sensing Properties of Porous Silicon

We report the effects of thermal oxidation on the sensing properties of porous silicon. Porous silicon substrates were prepared by electrochemical etching and thermally oxidized at different temperatures. A comparative EDS analysis shows that porous surfaces oxidized at higher temperatures have higher oxygen-to-silicon ratios. Our results indicate that the chemoresistive response due to the presence of isopropanol vapors at room temperature also increases with an increasing oxidation temperature. The presence of oxygen atoms in the PS layer could both protect the sensor from further atmospheric oxidation and increase its sensitivity