66 research outputs found
The characterisation of the microstructure and mechanical properties of diamond - like carbon (DLC) for endoprosthesis
The paper presents the results of research of DLC coating of a - C:H type obtained by using a technique of physical vapor deposition (PVD) on the surface of CoCrMo alloy, commonly used for the elements of the endoprosthesis. The surface has been observed using a scanning electron microscope (SEM). Analysis of the chemical composition and distribution of the different elements were performed using glow discharge optical emission spectrometry analysis (GDOES). It has been shown that the DLC elements are characterized by high hardness and good adhesion to the substrate
The characterisation of pure titanium for biomedical applications
The paper presents results of research on the use of pure titanium medical implants, dental and orthopedics – as pins hip replacements. The properties of metal biomaterials, including their hardness, determine the usefulness of the material and are one of the criteria for its use. They depend on their chemical composition and structure. Studies included the observation of the microstructure and mechanical properties of pure titanium. The observations surface were carried out using a scanning electron microscope SEM. The optical profiler was used to depict the geometric structure of the surface, and to carry out the nanoindentation tests a nano hardness tester was used
Information fusion in multi-agent system based on reliability criterion
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-00369-6_13The paper addresses the problem of information fusion in Multi-Agent System. Since the knowledge of the process state is distributed between agents, the efficiency of the task performance depends on a proper information fusion technique applied to the agents. In this paper we study the case in which each agent has its own sensing device and is able to collect information with some certainty. Since the same information can be detected by multiple agents, the global certainty about the given fact derives from the fusion of information exchanged by interconnecting agents. The key issue in the method proposed, is an assumption that each agent is able to asses its own reliability during the task performance. The method is illustrated by the pick-up-and-collection task example. The effectiveness of the method proposed is evaluated using relevant simulation experiments.Mellado Arteche, M.; Skrzypczyk, K. (2013). Information fusion in multi-agent system based on reliability criterion. En Vision Based Systemsfor UAV Applications. Springer. 207-217. doi:10.1007/978-3-319-00369-6_13S207217Cheng, X., Shen, J., Liu, H., Gu, G.: Multi-robot Cooperation Based on Hierarchical Reinforcement Learning. In: Shi, Y., van Albada, G.D., Dongarra, J., Sloot, P.M.A. (eds.) ICCS 2007, Part III. LNCS, vol. 4489, pp. 90–97. Springer, Heidelberg (2007)Harmati, I., Skrzypczyk, K.: Robot team coordination for target tracking using fuzzy logiccontroller in game theoretic framework. Robotics and Autonomous Systems 57(1) (2009)Jones, C., Mataric, M.: Adaptive Division of Labor in Large-Scale Minimalist Multi-Robot Systems. In: Proc. of IEEE/RSJ International Conference on Intelligent Robots and Systems, Las Vegas, pp. 1969–1974 (2003)Kaminka, G.A., Erusalimchik, D., Kraus, S.: Adaptive Multi-Robot Coordination: A Game-Theoretic Perspective. In: Proc. of IEEE International Conference on Robotics and Automation, Anchorage Convention District, Anchorage, Alaska, USA (2002)Kok, J.R., Spaan, M.T.J., Vlassis, N.: Non-communicative multi-robot coordination in dynamic environments. Robotics and Autonomous Systems 50(2-3), 99–114 (2005)Klusch, M., Gerber, A.: Dynamic coalition formation among rational agents. IEEE Intelligent Systems 17(3), 42–47 (2002)Kraus, S., Winkfeld, J., Zlotkin, G.: Multiagent negotiation under time constraints. Artificial Intelligence 75, 297–345 (1995)Kraus, S.: Negotiation and cooperation in multiagent environments. Artificial Intelligence 94(1-2), 79–98 (1997)Mataric, M., Sukhatme, G., Ostergaard, E.: Multi-Robot Task Allocation in Uncertain Environments. Autonomous Robots 14, 255–263 (2003)Schneider-Fontan, M., Mataric, M.J.: Territorial Multi-Robot Task Division. IEEE Transactionson Robotics and Automation 14(5), 815–822 (1998)Winkfeld, K.J., Zlotkin, G.: Multiagent negotiation under time constraints. Artificial Intelligence (75), 297–345 (1995)Wooldridge, M.: An Introduction to Multiagent Systems. Johnn Wiley and Sons Ltd., UK (2009) ISBN:978-0-470-51946-2Vail, D., Veloso, M.: Dynamic Multi-Robot Coordination. In: Schultz, A., et al. (eds.) Multi Robot Systems: From Swarms to Intelligent Automata, vol. II, pp. 87–98. Kluwer Academic Publishers, The Netherlands (2003)Gałuszka, A., Pacholczyk, M., Bereska, D., Skrzypczyk, K.: Planning as Artifficial Intelligence Problem-short introduction and overview. In: Nawrat, A., Simek, K., Świerniak, A. (eds.) Advanced Technologies for Intelligent Systems of National Border Security. SCI, vol. 440, pp. 95–104. Springer, Heidelberg (2013)Jędrasiak, K., Bereska, D., Nawrat, A.: The Prototype of Gyro-Stabilized UAV Gimbal for Day-Night Surveillance. In: Nawrat, A., Simek, K., Świerniak, A. (eds.) Advanced Technologies for Intelligent Systems of National Border Security. SCI, vol. 440, pp. 107–116. Springer, Heidelberg (2013)Galuszka, A., Bereska, D., Simek, K., Skrzypczyk, K., Daniec, K.: Application of graphs theory methods to criminal analysis system. Przeglad Elektrotechniczny 86(9), 278–283 (2010
The geological cycle of plastics and their use as a stratigraphic indicator of the Anthropocene
The rise of plastics since the mid-20th century, both as a material element of modern life and as a growing environmental pollutant, has been widely described. Their distribution in both the terrestrial and marine realms suggests that they are a key geological indicator of the Anthropocene, as a distinctive stratal component. Most immediately evident in terrestrial deposits, they are clearly becoming widespread in marine sedimentary deposits in both shallow- and deep-water settings. They are abundant and widespread as macroscopic fragments and virtually ubiquitous as microplastic particles; these are dispersed by both physical and biological processes, not least via the food chain and the ‘faecal express’ route from surface to sea floor. Plastics are already widely dispersed in sedimentary deposits, and their amount seems likely to grow several-fold over the next few decades. They will continue to be input into the sedimentary cycle over coming millennia as temporary stores – landfill sites – are eroded. Plastics already enable fine time resolution within Anthropocene deposits via the development of their different types and via the artefacts (‘technofossils’) they are moulded into, and many of these may have long-term preservation potential when buried in strata
Colonization of the Americas, 'Little Ice Age' climate, and bomb-produced carbon: their role in defining the Anthropocene
A recently published analysis by Lewis and Maslin (Lewis SL and Maslin MA (2015) Defining the Anthropocene. Nature 519: 171–180) has identified two new potential horizons for the Holocene−Anthropocene boundary: 1610 (associated with European colonization of the Americas), or 1964 (the peak of the excess radiocarbon signal arising from atom bomb tests). We discuss both of these novel suggestions, and consider that there is insufficient stratigraphic basis for the former, whereas placing the latter at the peak of the signal rather than at its inception does not follow normal stratigraphical practice. Wherever the boundary is eventually placed, it should be optimized to reflect stratigraphical evidence with the least possible ambiguity
Mesoporous carbon-containing voltammetric biosensor for determination of tyramine in food products
A voltammetric biosensor based on tyrosinase (TYR) was developed for determination of tyramine. Carbon material (multi-walled carbon nanotubes or mesoporous carbon CMK-3-type), polycationic polymer—i.e., poly(diallyldimethylammonium chloride) (PDDA), and Nafion were incorporated into titania dioxide sol (TiO(2)) to create an immobilization matrix. The features of the formed matrix were studied by scanning electron microscopy (SEM) and cyclic voltammetry (CV). The analytical performance of the developed biosensor was evaluated with respect to linear range, sensitivity, limit of detection, long-term stability, repeatability, and reproducibility. The biosensor exhibited electrocatalytic activity toward tyramine oxidation within a linear range from 6 to 130 μM, high sensitivity of 486 μA mM(−1) cm(−2), and limit of detection of 1.5 μM. The apparent Michaelis–Menten constant was calculated to be 66.0 μM indicating a high biological affinity of the developed biosensor for tyramine. Furthermore, its usefulness in determination of tyramine in food product samples was also verified. [Figure: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00216-016-9612-y) contains supplementary material, which is available to authorized users
Is the Anthropocene distinct from the Holocene? [abstract only]
The inaugural meeting of the Anthropocene Working Group of the Subcommission on Quaternary Stratigraphy in Berlin (Oct. 2014) produced a consensus statement that “humans have altered geologic processes across the Earth system sufficiently to cause a planetary transition to a new interval of geological time”, with the timing of the onset the focus of continued debate, but with a majority in favour of a mid-20th century beginning. The name has driven the assumption that the Anthropocene should be an epoch, but are its signatures truly driven out of the range evident for most of the Holocene, or are changes comparable or subsidiary to Holocene stages?
The evidence rests upon a broad range of signatures reflecting humanity’s significant and increasing modification of Earth systems. These are visible in anthropogenic deposits in the form of the greatest expansion of novel minerals in the last 2.4 billion years and development of ubiquitous materials, such as plastics, present in the environment only in the last 60 years. Globally distributed spherical carbonaceous particles of fly ash represent another near-synchronous and permanent proxy. The artefacts we produce, the technofossils of the future, provide a decadal to annual stratigraphical resolution. These materials and deposits have in recent decades extended into the oceans and increasingly into the subsurface both onshore and offshore. These anthropogenic deposits are transported at rates exceeding those of the sediment carried by rivers by an order of magnitude, fluvial systems themselves showing widespread sediment retention in response to dam construction across most major river systems. The Anthropocene is evident in sediment and glacial ice strata as chemical markers. CO2 in the atmosphere has risen by ~45 percent above pre-Industrial Revolution levels, mainly through combustion of hydrocarbons over a few decades. Although average global temperature increases and resultant sea-level rises are still comparatively small, the shift to more negative δ13C values in tree-rings, limestones, speleothems, calcareous fossils and δ13CO2 in ice forms a permanent record. Nitrogen and phosphorus contents in surface soils has approximately doubled through increased use of fertilizers to increase agricultural yields as the human population has also doubled in the last 50 years. Industrial metals such as Cd, Cr, Cu, Hg, Ni, Pb, Zn and persistent organic compounds have been widely and rapidly dispersed. A clear novel signature is radioactive fallout from atomic weapons testing, initiated in 1945 but becoming global in 1952 and in the case of Pu239 representing a long-lasting marker event. The Earth still has most of its complement of biological species, though many now as small populations: current trends of habitat loss and predation, if maintained, will push the Earth into the sixth mass extinction event in the next few centuries. Dramatic elapsed changes include trans-global species invasions and population modification through agricultural development on land and contamination of coastal zones. Although these changes are not synchronous, within near coastal environments microfauna/flora commonly show pronounced assemblage changes in the mid-20th century.
Considering the entire range of environmental changes reflected in stratigraphic signatures, the global, large and rapid scale of change related to the mid-20th century is clearly distinct from previous Holocene signatures, consistent with interpretation of the Anthropocene as a potential epoch
The study of rare earth elements in farmer's well waters of the Podwiśniówka acid mine drainage area (south-central Poland)
Chemical Derivatization Processes Applied to Amine Determination in Samples of Different Matrix Composition
Mesoporous carbon-containing voltammetric biosensor for determination of tyramine in food products
- …