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In-situ synthesized Nb(C,N) reinforced metal-ceramic composite layers were fabricated on nitridable (16MnCr5) and non-nitridable (S235J) steel surface by combined laser melt injection technology and ferritic nitrocarburizing treatment. The feasibility of processing composites layer by an in situ reaction using laser beam were carried out. Beside that the hardness of the treated layers increases up to 1000-1170 HV0.5 in the diffusion zone and after it the hardness of the samples reach 300-450 HV0.5, which is related the Nb alloying depth (1200-1400 μm). The results of the composite layer are presented in this paper. © (2015) Trans Tech Publications, Switzerland.

Carreira M.,Rua Alves Redol | Ting K.L.H.,University of Technology of Troyes | Csobanka P.,Bay Zoltan Nonprofit Ltd. for Applied Research | Goncalves D.,Rua Alves Redol
Universal Access in the Information Society | Year: 2016

In-air gestural interfaces are gaining popularity due to the increasing availability and low cost of gesture recognition hardware. However, the current literature mainly focuses either on the young adult user group or, when focusing on older people, most studies limit the focus to physical activity or gaming contexts. The suitability of in-air gestural interactions for seniors to control graphical user interfaces in general remains largely unknown. Moreover, since gestural interfaces are considered easy and natural to use, they may represent an advantageous interaction modality for older people. In this study, the authors evaluate the usability of in-air hand gestures for seniors to interact with generic graphical user interfaces. A user study was conducted with 40 participants, where two types of tasks were evaluated: navigation and selection. For each task, two alternative gestures were evaluated: Swipe and Grab and Drag for navigation tasks; Point and Hold and Point and Push for selection tasks. Both qualitative and quantitative feedbacks were gathered, and then, each alternative gesture was systematically compared. Almost all participants (97 %) completed the navigation and selection tasks with at least one gesture, finding this type of interaction enjoyable to use. From the results and observations, the authors propose a set of design implications that future developers can take into account when developing hand gestural interactions for older people. © 2016 Springer-Verlag Berlin Heidelberg

Buday B.,Drug Research Center | Pach F.P.,Bay Zoltan Nonprofit Ltd. for Applied Research | Literati-Nagy B.,Drug Research Center | Vitai M.,Drug Research Center | And 2 more authors.
Bone | Year: 2013

Objective: The osteoblast-derived protein osteocalcin (OCN) is known to be involved in glucose metabolism by increasing adiponectin secretion from adipocytes. Recently, OCN was also found to enhance testosterone production in mouse testes, suggesting that OCN effects on energy metabolism may be mediated through testosterone. Our aim was to assess a possible gender difference in the metabolic effect of OCN in humans. Methods: We included 135 women and 155 men exhibiting changes in glucose tolerance in our study. Oral and intravenous glucose tolerance tests (OGTT and IVGTT, respectively) and a hyperinsulinemic normoglycemic clamp were performed. For clamp indices, whole body (M1) and muscle (M2) glucose uptake values were used. Leptin, adiponectin serum lipid, lipoprotein, total serum OCN and testosterone levels, and body composition were determined. Results: Higher OCN values were associated with improving metabolic state in both genders. Adiponectin and OCN correlated significantly only in females (r. = +. 0.254, p. = 0.0029), while in men, testosterone and OCN values showed a significant positive correlation (r. = +. 0.243, p. = 0.0023), independent of age, BMI, HbA1c and body composition. In women, adiponectin was confirmed by feature selection analysis as being an independent determinant of OCN, in addition to age and three of the IVGTT glucose values. In men, besides M1, BMI, M2, leptin, body fat percent, and the 90-minute OGTT glucose reading testosterone, but not adiponectin were identified as independent contributors for OCN. Conclusion: We confirmed the 'classic' adiponectin-mediated insulin-sensitising effect of OCN only in females. In men, a testosterone-mediated OCN metabolic effect is more likely. © 2013 Elsevier Inc.

Danku Z.,Debrecen University | Lenkey G.B.,Bay Zoltan Nonprofit Ltd. for Applied Research | Kun F.,Debrecen University
Applied Physics Letters | Year: 2015

We study the statistical features of magnetic noise accompanying the dynamic fracture of steel samples during mixed type fracture, where the overall ductile character of crack propagation is interrupted by a sudden brittle jump. The structure of the voltage time series is investigated by identifying discrete peaks which correspond to elementary steps of the jerky cracking process. We show that the height, duration, area, and energy of peaks have power law distributions with exponents falling close to the corresponding values of pure ductile fracture. For single peaks, a power law correlation of the height and area with the width is evidenced; however, the mixed nature of fracture gives rise to a crossover between two regimes of different exponents. The average pulse shape of micro-cracking events has a parabolic form with a right handed asymmetry similarly to quasi-static fracture propagation. The asymmetry emerges due to stress localization at the advancing crack front. © 2015 AIP Publishing LLC.

Furko M.,Bay Zoltan Nonprofit Ltd. for Applied Research | Jiang Y.,University of Leeds | Wilkins T.,University of Leeds | Balazsi C.,Bay Zoltan Nonprofit Ltd. for Applied Research
Ceramics International | Year: 2016

A successful electrodeposition method for preparing silver and zinc modified bioactive calcium phosphate layers onto surgical grade titanium alloy material (Ti6Al4V) was developed. The coatings were deposited on the Ti6Al4V surface by pulse current at 70 °C from an electrolyte containing adequate amounts of calcium nitrate, ammonium dihydrogen phosphate, zinc nitrate and silver nitrate. The corrosion resistivity of the bioceramic coatings was assessed in conventional Ringer's solution in a three electrode open cell by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results revealed the pure bioactive calcium phosphate (CaP) coated implant materials to possess the highest resistivity to corrosion, while the silver and zinc doped CaP layer showed at least one order of magnitude lower corrosion resistance. These modified CaP coatings can be further considered as antimicrobial coatings with enhanced biocompatibility. The morphology and structure of the coatings were characterized by Scanning electron microscopy (SEM), Energy-dispersive X-ray Spectroscopy (EDX) and X-ray diffraction (XRD) that confirmed the pulse current deposited CaP layer to consist of a mixture of different calcium phosphate phases such as hydroxyapatite (HAp), monetite (dicalcium phosphate, CaHPO4) as well as other Ca-containing components, portlandite (Ca(OH)2) and parascholzite (CaZn2(PO4)2(H2O)2). © 2015 Elsevier Ltd and Techna Group S.r.l.

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