A complex physiology-based empirical usability evaluation method in practice

This paper outlines the INTERFACE usability evaluation methodology developed by researchers of our department. It is based on the simultaneous assessment of Heart Period Variability (HPV), Skin Conductance (SC), and other data. One of the highlights of this methodology is its capability to identify quality attributes of software elements with a time-resolution of only a few seconds: in particular cases it can assess 2- or 3-second events. The Department of Ergonomics and Psychology at the Budapest University of Technology and Economics carried out applied research projects assessing very various software. After these, we can show different types of typical software problems identified by our method. The method of analysis allows us not only to decide what types of problems are significant to the users; however, on the other hand, the method allows us to decide, to what extent the found problems and their assessed severity concern all the users in general, or how these things depend on the type and characteris tics of the users

Zinc-rich paint coatings containing either ionic surfactant-modified or functionalized multi-walled carbon nanotube-supported polypyrrole utilized to protect cold-rolled steel against corrosion

The intense anodic action of sacrificial zinc pigments ensured viable galvanic function of the highly porous liquid zinc-rich paints (ZRPs) result in deteriorated long-term corrosion resistance often accompanied by cathodic delamination phenomena. In our approach, such a efficacy problem related to the corrosion preventive function of ZRPs is addressed by the application of intimately structured anodic inhibitor particles composed of nano-size alumina and either polyelectrolyte-modified or chemically functionalized multi-walled carbon nanotubes (MWCNT) supported polypyrrole (PPy) in one specific zinc-rich hybrid paint formulation providing balanced active–passive protective functionality. High dispersity of the nanotube-free PPy-deposited inhibitor particles (PDIPs) with uneven polymer distribution on the alumina carrier was confirmed by transmission electron microscopy (TEM) observations. Furthermore, the MWCNT-embedded PDIPs indicated almost complete surface coverage of the alumina-nanotube carriers by PPy with decreased microstructure dispersity which is attributed to the effect of double-flocculants type co-deposition of the oppositely charged polymers causing coalescence of the modified particles. Depending on the amount of the nanotubes and their proportion to the quantities of the deposited PPy and polyelectrolyte as well as the concentration of the surfactant, varied micron-scale association of the PDIPs in the suspensions of dissolved alkyd matrix was disclosed by rheology characterization carried out at particular solid contents similar to hybrid paint formulation. The evenly distributed but less densely packed nano-structure of PPy was evidenced on the polyelectrolyte-modified nanotubes by Fourier-transform infrared (FTIR) spectroscopy whereas more compact polymer film formation was confirmed on the surface of functionalized nanotubes. According to the greater electrical conductivity, enhanced electroactivity and reversibility of the nanotube-embedded PDIPs were indicated over the nanotube-free particles by cyclic voltammetry, depending on the type and the amount of the nanotubes and their modification. Protection function of the hybrid paint coatings (formulated with spherical zinc pigment at 70 wt.%) was investigated by immersion and salt-spray chamber tests over 254 and 142 day periods, respectively. Firm barrier nature of the nanotube-embedded PDIP contained hybrids was proved by electrochemical impedance spectroscopy (EIS) and radio-frequency glow-discharge optical-emission-spectroscopy (RF-GD-OES). Furthermore, due to the increased conductivity of the nanotube-embedded PDIPs cemented in epoxy primers optimally at 0.4 and 0.6 wt.%, altered corrosion preventive behaviour of the hybrid coatings was indicated by the positively polarized open-circuit potentials (OCPs) and the X-ray photoelectron spectroscopy (XPS) detected lower relative quantities of the interfacially accumulated zinc corrosion products, moderate oxidative degradation of the epoxy vehicle. Decreasing oxidative conversion of iron at the surface was indicated by XPS found to correlate with the increasing intensity of zinc corrosion and decreasing oxidative degradation of the epoxy binder, according to the higher nanotube contents of hybrid coatings. In addition, inhibited zinc corrosion caused low rate of oxidative degradation of epoxy, allowing increased durability of coating adhesion and cohesion thereby ensuring reliable protection by zinc-rich compositions. As a conclusion, modified or functionalized MWCNTs acting as unexchangeable doping agents promote enhanced reversibility and increased conductivity of PPy, forming nano-size inhibitor particles with advanced features. Thus, such inhibitor nano-particles in zinc-rich hybrid compositions afford improved barrier and high efficiency galvanic–cathodic corrosion preventive function, exceeding long-term protection capability of the conventional ZRPs

Nanoszerkezetek vizsgálata és módosítása ionsugarakkal = Investigation and modification of nanostructures by ion beam

A nanoszerkezetek (nm-es dimenziójú rendszerek) mind a szilárdtestfizikai alapkutatás, mind pedig a technológiai alkalmazások szempontjából érdekesek. A nanoszerkezetek közé tartozik minden olyan szerkezet, amelynek egy vagy több dimenziója esik a nm-es mérettartományba, így a rétegszerkezetek, a nanokristályok vagy a porózus szerkezetek is. A kísérleteink tárgyát képező különféle nanoszerkezeteket - mind a fémes, félvezető és szigetelő rétegek és hordozók esetén - a technológiai szempontból érdekes problémák alapján választottuk. Vizsgáltuk a GMR tulajdonságot mutató Fe/Ag rendszert, orvosi implantátumok anyagaiként használható vanádiummentes titánötvözeteket oxidációs tulajdonságait, félvezető anyagokban az ionimplantációval okozott hibastruktúrákat, gyémántszerű szénrétegeket, a SiO2-ba implantált hélium viselkedését, mágneses nanohuzalokat, halak fülkövét (otolith), granuláris nanokompozitok mágneses és transzport tulajdonságait. A mérések kiértékeléséhez folyamatosan fejlesztettük kiértékelő programjainkat, ezek közül kiemelhető a nanoszerkezeteken történő visszaszórási spektrometria értelmezésére használható RBS-MAST program továbbfejlesztése. | The nanostructures (systems with nm dimension) are interesting also for fundamental research in solid-state physics and for the technological applications. All structures, for which one and more dimensions fall into the nm size ranges are called nanostructures eg., layer structures, nanocrystals and porous materials. Various nanostructures are subject of our experiments - metallic, semi-conductor and insulating layers on substrates. All of them were chosen as technologically interesting problems. Fe/Ag systems showing GMR characteristic, magnetic nanowires, magnetic and transport properties of granular nanocomposits, oxidising properties of vanadium free titanium alloys as the substances of medical implants, diamond-like carbon layers, ion implantation induced damage in semiconductor materials, the behaviour of ion implanted helium in SiO2 and the ear stones of fish (otolith) were investigated. To interpret the measurements our programs were developed further, we may stress the importance of RBS-MAST code, which is used for backscattering spectrometry on the nanostructures

Comparative Analysis of Antimicrobial Resistance and Virulence Genotypes of Escherichia coli from Poultry Meat and Young Chicks.

Recent studies indicated that some highly resistant strains of E. coli can be common contaminants of broiler meat, and resistance determinants can be of importance for the food production and human health. However, much less is known about their virulence determinants, and detailed genetic analyses of antimicrobial resistance and virulence are especially missing in E. coli from newly hatched broiler chicks. We aimed to provide a comparative description of antimicrobial resistance and virulence of E. coli isolates from young chicks from farms and from fresh broiler meat. A total of 70 E. coli isolates characterized here derived from different poultry sources: raw meat (28), young chicks from farms (represented by 11 intestinal- and 11 extraintestinal strains) and 20 E. coli isolates from newly hatched chicks. Resistance and virulence genotyping was performed using high throughput PCR microarray systems, AMR05 and Ec03 respectively. The tetra-resistant phenotype of streptomycin-nalidixic acid-sulfonamide-tetracycline commonly occured among E. coli strains from different chicken sources. The antimicrobial resistance genotype of E. coli strains from raw meet showed the highest similarity with the intestinal strains from young chicks. The high prevalence of antimicrobial resistance genes related to the flexible genome indicate the commonly high distribution of certain mobile genetic elements in poultry E. coli. Obviously, the predominance of the virulence genes in the extraintestinal E. coli strains was not surprising, however some of the virulence genes (iss, tsh, iutA) showed high prevalence in commensal isolates from newly hatched chicks and from the meat. Results indicate that E. coli from newly hathed chicks may represent a reservoir for multiresistance and virulence for both pathogenic and commensal E. coli strains of young chicks and of poultry meat. Acknowledgement: This work was supported by EU FP7 Collaborative Project PROMISE. Ama Szmolka is a holder of János Bolyai Research Scholarship of the HAS

Johann Alexander Reiner Észak-Magyarország térképének változatai

A tanulmány célja Johann Alexander Reiner 1682-ben készült Észak-Magyarország térképe jelenleg ismert változatainak kartobibliográfiai szempontú áttekintése és pontosítása; ennek részeként a külföldi közgyűjteményekben a közelmúltban felbukkant példányok, valamint a hazai szakirodalomban eddig ismert egyetlen darab tartalmi sajátosságainak összevetése és a kiadási sorrend meghatározása

Protein molekulák adszorpciójának in situ molekuláris szintű jellemzése fogászati implantátumok nanostrukturált felületén összegfrekvencia-keltési spektroszkópiával = Adsorption of protein molecules on nanostructured surfaces of dental implants: in situ molecular level studies by Sum Frequency Generation Spectroscopy

A titán részben kedvező mechanikai tulajdonságai, részben a felületén kialakuló oxidréteg sajátosságai miatt a legszélesebb körben felhasznált biokompatibilis fém. A projekt alapvető célkitűzése a biokompatibilitás molekuláris hátterének tanulmányozása volt aminosavak és proteinek titán-dioxidon és más biológiai szempontból potenciálisan jelentős felületeken lejátszódó adszorpciójának összegfrekvencia-keltési spektroszkópiai vizsgálata segítségével. Számos aminosavra vonatkozó eredményeink alapján megállapítottuk, hogy a kvarcüveg-aminosav oldat határfelületen nem alakul ki rendezett adszorbeált réteg, míg a kalcium-fluorid-aszparaginsav oldat határfelületen aminosav kristályok nukleálódása figyelhető meg. Az aminosavak többsége a titán-dioxidon is gyengén adszorbeálódik, egyedül a savas oldalláncú aminosavak, mint az aszparaginsav vagy a glutaminsav, alkotnak rendezett adszorbeált réteget. Az aszparaginsav példáján keresztül tisztáztuk a savas aminosavak titán-dioxidhoz való kötődésének részleteit és meghatároztuk az adszorbeátumok orientációját. Fehérjeadszorpcióval kapcsolatos vizsgálataink során módszert dolgoztunk ki a határfelületen elhelyezkedő protein molekulák orientációs paramétereinek kombinált lineáris és nemlineáris optikai spektroszkópiai mérések alapján történő meghatározására. Egy gyakorlati példa kapcsán molekuláris szintű modellt adtunk a véralvadási kaszkád töltött felületen adszorbeálódó XII. faktorának aktiválódási mechanizmusára. | Due to the favorable properties of its surface oxide, titanium is the most widely used biocompatible metal. The most important purpose of this project was to investigate the molecular level background of biocompatibility by means of sum frequency generation vibrational spectroscopy study of adsorption of amino acids and proteins on titanium-dioxide and other biologically important surfaces. It was established that no ordered amino acid adsorbate layer forms at the fused silica-amino acid solution interface. On the contrary, at the calcium fluoride-solution interface growth of randomly oriented aspartic acid crystallites was observed. Although most amino acids were found to adsorb weakly on titanium dioxide, our measurements revealed that acidic amino acids like aspartic acid or glutamic acid form a stable, uniform, ordered overlayer. The bonding mechanism and the orientation of the aspartic acid adsorbates were analyzed in detail. Concerning protein adsorption, a method was proposed for determination of the orientation parameters of interfacial protein molecules by combining data from linear and nonlinear optical spectroscopic measurements. Finally, the interaction of the blood coagulation Factor XII with charged surfaces was studied and a molecular level model was suggested for its autoactivation

Stress model for the wrinkling of ion-implanted layers

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Mechanism of NO-SCR by methane over Co,H-ZSM-5 and Co,H-mordenite catalysts

Results of X-ray photoelectron spectroscopic (XPS) examination and temperatureprogrammed reduction measurements by H2 (H2-TPR) showed that the Co-zeolite catalysts, which were found most active in the selective catalytic reduction of NO by methane to N2 in the presence of excess O2 (NO-SCR), contain both Co2+/[Co-OH]+/H+ exchange cations, Cooxo species and cobalt oxide clusters. Using operando Diffuse Reflectance Infrared Fourier Transform Spectroscopic method (DRIFTS method) the NO-SCR reaction was shown to proceed in consecutive steps via bifunctional mechanism over active sites (i) promoting the oxidation of NO by O2 to NO2 (NO-COX reaction), and sites (ii) whereon disproportionation and charge separation of 2NO2 generates activated surface intermediate NO3 -/NO+ ion pair. Latter process was found to require Co2+ zeolite cations. The NO-COX reaction was shown to proceed over Co-oxo species and cobalt oxide, if present, and also over Brønsted acid sites but at a significantly lower rate. In the reaction of methane and the NO3 -/NO+ ion pair CO2, H2O, and N2 was formed and the active Co2+ sites were recovered (CH4/NO-SCR reaction). The surface concentration of the NO3 -/NO+ ion pair must have been controlled by the relative magnitude of the apparent rate constants of the consecutive NO-COX and CH4/NO-SCR reactions. Below about 700 K reaction temperature latter reaction governed the rate of the consecutive NO reduction process. Above about 700 K combustion became the main reaction of methane. Because of the low equilibrium NO2 concentration at these high temperatures the NO-COX reaction took over the control over the rate of the NO-SCR process. Under steady state reaction conditions a temperature-dependent fraction of the Co2+ active sites was always poisoned by adsorbed H2O formed in the CH4 oxidation reaction