67 research outputs found

    Magnon and Phonon Excitations in Nanosized NiO

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    Single-crystal, microcrystalline and nanocrystalline nickel oxides (NiO) have been studied by Raman spectroscopy. A new band at ~200 cm-1 and TO-LO splitting of the band at 350–650 cm-1 have been found in the spectra of single-crystals NiO(100), NiO(110) and NiO(111). The Raman spectra of microcrystalline (1500 nm) and nanocrystalline (13–100 nm) NiO resemble those of the single crystals. They all contain the two-magnon band at 1500 cm-1, indicating that the oxides remain at room temperature in the antiferromagnetic phase. Besides, a new sharp Raman band has been observed at 500 cm-1 in nanocrystalline NiO. Its temperature dependence suggests the magnetic origin of the band, possibly associated with the one-phonon–one-magnon excitation at the Brillouin zone centre.Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

    Erratum to: Methods of Electron Microdiffraction and X-Ray Analysis in Structure Study of Nanodisperse Partially Stabilized ZrO2 Powders

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    Analytical electron microscopy (AEM) has been used to study both structure and morphology of partially yttria-stabilized zirconia dioxide nanopowders (YSZ) obtained by wet-chemical methods (glycine and azeotropic distillation) and ceramics produced from them. Both morphological and structural inhomogeneity of nanopowders obtained by glycine (glc) method has been estimated. Besides the tetragonal ZrO2 phase (results of X-ray analyses) the cubic phase of ZrO2 with different degree of crystallinity has been estimated by Electron Microdiffraction (EMD) methods. In powders obtained by azeotropic distillation (dest) method besides the amorphous phase (identified in X-ray investigations) the high disperse cubic zirconia phase has been identified using high local EMD method. It has been detected the yttrium influence on the degree of crystallinity in nanopowders obtained by azeotropic distillation method without yttria (dest-0YSZ) and with 5 wt % Y2O3 (dest-5YSZ). It has been determined the difference in ceramic morphology produced from these powders. Ceramics mode of nanopowders containing yttria (glc-5YSZ and dest-5YSZ) have a homogeneous surface which consists of different size globules (0.1–0.6 μm) and contains some little pores (∼370 nm). Ceramics mode of nanopowders without yttria have inhomogeneous surface with numerous cracks. Separate parts of the latter ceramics consist of globules, their sizes are of 0.2–0.5 μm.Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

    The pion mass dependence of the nucleon form-factors of the energy momentum tensor in the chiral quark-soliton model

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    The nucleon form factors of the energy-momentum tensor are studied in the large-Nc limit in the framework of the chiral quark-soliton model for model parameters that simulate physical situations in which pions are heavy. This allows for a direct comparison to lattice QCD results.Comment: 17 pages, 12 figure

    Soft X-ray resonant scattering study of single-crystal LaSr2_2Mn2_2O7_7

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    Soft X-ray resonant scattering studies at the Mn LII, IIIL_{\texttt{II, III}}- and the La MIV, VM_{\texttt{IV, V}}- edges of single-crystal LaSr2_2Mn2_2O7_7 are reported. At low temperatures, below TN160T_\texttt{N} \approx 160 K, energy scans with a fixed momentum transfer at the \emph{A}-type antiferromagnetic (0 0 1) reflection around the Mn LII, IIIL_{\texttt{II, III}}-edges with incident linear σ\sigma and π\pi polarizations show strong resonant enhancements. The splitting of the energy spectra around the Mn LII, IIIL_{\texttt{II, III}}-edges may indicate the presence of a mixed valence state, e.g., Mn3+^{3+}/Mn4+^{4+}. The relative intensities of the resonance and the clear shoulder-feature as well as the strong incident σ\sigma and π\pi polarization dependences strongly indicate its complex electronic origin. Unexpected enhancement of the charge Bragg (0 0 2) reflection at the La MIV, VM_{\texttt{IV, V}}-edges with σ\sigma polarization has been observed up to 300 K, with an anomaly appearing around the orbital-ordering transition temperature, TOO220T_{\texttt{OO}} \approx 220 K, suggesting a strong coupling (competition) between them.Comment: Accepted by European Physical Journal

    Role of defects and disorder in the half-metallic full-Heusler compounds

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    Half-metallic ferromagnets and especially the full-Heusler alloys containing Co are at the center of scientific research due to their potential applications in spintronics. For realistic devices it is important to control accurately the creation of defects in these alloys. We review some of our late results on the role of defects and impurities in these compounds. More precisely we present results for the following cases (i) doping and disorder in Co2_2Cr(Mn)Al(Si) alloys, (ii) half-metallic ferrimagnetism appeared due to the creation of Cr(Mn) antisites in these alloys, (iii) Co-doping in Mn2_2VAl(Si) alloys leading to half-metallic antiferromagnetism, and finally (iv) the occurrence of vacancies in the full-Heusler alloys containing Co and Mn. These results are susceptible of encouraging further theoretical and experimental research in the properties of these compounds.Comment: Chapter intended for a book with contributions of the invited speakers of the International Conference on Nanoscale Magnetism 2007. Revised version contains new figure

    Capability driven development: an approach to designing digital enterprises

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s12599-014-0362-0[EN] The need for organizations to operate in changing environments is addressed by proposing an approach that integrates organizational development with information system (IS) development taking into account changes in the application context of the solution. This is referred to as Capability Driven Development (CDD). A meta-model representing business and IS designs consisting of goals, key performance indicators, capabilities, context and capability delivery patterns, is being proposed. The use of the meta-model is validated in three industrial case studies as part of an ongoing collaboration project, whereas one case is presented in the paper. Issues related to the use of the CDD approach, namely, CDD methodology and tool support are also discussed.This work has been partially supported by the EU-FP7 funded project no: 611351 CaaS - Capability as a Service in Digital Enterprises.Berzisa, S.; Bravos, G.; Cardona Gonzalez, T.; Czubayko, U.; España, S.; Grabis, J.; Henkel, M.... (2015). Capability driven development: an approach to designing digital enterprises. Business and Information Systems Engineering. 57(1):15-25. https://doi.org/10.1007/s12599-014-0362-0S1525571ArchiMate (2013) An enterprise modeling language from the Open Group. http://www.opengroup.org/archimate/ . Accessed 3 Dec 2014Asadi M, Ramsin R (2008) MDA-based methodologies: an analytical survey. In: Proceedings Model driven architecture – foundations and applications (ECMDA-FA 2008), LNCS 5095, pp 419–431Barney JB (1991) Firm resources and sustained competitive advantage. J Manag 17(1):99–120Bērziša S, Bravos G, Gonzalez Cardona T, Czubayko U, España S, Grabis J, Henke lM, Jokste L, Kampars J, Koc H, Kuhr J, Llorca C, Loucopoulos P, Juanes Pascua lR, Sandkuh lK, Simic H, Stirna J, Zdravkovic J (2014) Deliverable 1.4: Requirements specification for CDD, CaaS – capability as a service for digital enterprises. FP7 project no 611351, Riga Technical University, Latvia. Submitted for reviewBubenko JA Jr, Persson A, Stirna J (2001) User guide of the knowledge management approach using enterprise knowledge patterns. Deliverable D3, IST programme project hypermedia and pattern based knowledge management for smart organisations. project no. IST-2000-28401, Royal Institute of Technology, SwedenBriand LC, Yue T, Labiche Y (2011) A systematic review of transformation approaches between user requirements and analysis models. Requir Eng 16:75–99De Kinderen S, Gordijn J, Akkermans H (2009) Reasoning about customer needs in multi-supplier ICT service bundles using decision models. In: Proceedings 11th international conference on enterprise information systems (ICEIS 2009), pp 131–136Deloitte (2009) Cloud computing: forecasting change. Deloitte Consulting, New York. http://public.deloitte.no/dokumenter/2_Cloud_Computing%5B1%5D.pdf . Accessed 3 Dec 2014Dey A (2001) Understanding and using context. Pers Ubiquitous Comput 5(1):4–7Gamma E, Helm R, Johnson R, Vlissides J (1995) Design patterns: elements of reusable object-oriented software architecture. Addison-Wesley, BostonGomes D, Gonçalves JM, Santos R, Aguiar R (2010) XMPP based context management architecture. In: Proceedings GLOBECOM workshop, IEEE, pp 1372–1377González A, España S, Ruiz M, Pastor Ó (2011) Systematic derivation of class diagrams from communication-oriented business process models. In: 12th working conference on business process modeling, development, and support (BPMDS’11). Springer LNBIP 81, pp 246–260Henkel M, Stirna J (2010) Pondering on the key functionality of model driven development tools: the case of mendix. In: Forbrig P, Günther H (eds) Proceedings business informatics research (BIR 2010), Springer LNBIP 64, pp 146–160Hervas R, Bravo J, Fontecha J (2010) A context model based on ontological languages – a proposal for information visualisation. J Univers Comput Sci 16(12):1539–1555Jarke M, Loucopoulos P, Lyytinen K, Mylopoulos J, Robinson W (2011) The brave new world of design requirements. Information Syst 36(7):992–1008Kaplan RS, Norton DP (2004) Strategy maps: converting intangible assets into tangible outcomes. Harvard Business School Press, BostonKleppe A, Warmer J, Bast W (2013) MDA explained. Addison-Wesley, BostonLoniewski G, Insfran E, Abrahao L (2010) A systematic review of the use of requirements engineering techniques in model-driven development. In: Proceedings model driven engineering languages and systems (MODELS 2010), Part II, LNCS 6395, pp 213–227Mohagheghi P, Dehlen V (2008) Where is the proof? - a review of experiences from applying MDE in industry. In: Proceedings model driven architecture – foundations and applications (ECMDA-FA 2008). LNCS 5095. Springer, Heidelberg, pp 432–443Nilsson AG, Tolis C, Nellborn C (eds) (1999) Perspectives on business modelling: understanding and changing organisations. Springer, HeidelbergOASIS (2011) Reference architecture foundation for service oriented architecture version 1.0, committee specification draft 03/public review draft 02 06 July 2011. http://docs.oasis-open.org/soa-rm/soa-ra/v1.0/soa-ra.pdf . Accessed 3 Dec 2014OMG (2011a) UML superstructure. http://www.omg.org/spec/UML/2.4.1/ . Accessed 3 Dec 2014OMG (2011b) Business process model and notation. http://www.omg.org/spec/BPMN/2.0/ . Accessed 3 Dec 2014Osterwalder A, Pigneur Y (2003) Modeling value propositions in e-business. Proc 5th international conference on electronic commerce (ICEC 2003). ACM Conference Proceedings Series 50Papazoglou MP, Yang J (2002) Design methodology for web services and business processes. In: Proceedings 3rd international workshop on technologies for e-services (TES 03). LNCS 2444. Springer, Heidelberg, pp 54–64Pastor O, Giachetti G (2010) Linking goal-oriented requirements and model-driven development. In: Intentional perspectives on information systems engineering. Springer, Heidelberg, pp 257–276Porter ME (1985) Competitive advantage: creating and sustaining superior performance. Free Press, New YorkRuiz M, Costal D, España S, Franch X, Pastor Ó (2014) Integrating the goal and business process perspectives in information system analysis. In: 26th International Conference on Advanced Information Systems Engineering (CAiSE 2014). LNCS 8484. Springer, Heidelberg, pp 332–346Sheng Q, Yu J, Dustar S (eds) (2010) Enabling context-aware web services: methods, architectures, and technologies. Chapman & Hall/CRC, Boca RatonSmanchat S, Ling S, Indrawan M (2008) A survey on context-aware workflow adaptations. In: Proceedings 6th international conference on advances in mobile computing and multimedia (MoMM 2008), New York, pp 414–417Stirna J, Grabis J, Henkel M, Zdravkovic J (2012) Capability driven development – an approach to support evolving organizations. In: The practice of enterprise modeling (PoEM 2012). LNBIP 134. Springer, Heidelberg, pp 117–131Vale S, Hammoudi S (2009) COMODE: a framework for the development of context-aware applications in the context of MDE. In: Proceedings 4th international conference on internet and web applications and services (ICIW 2009). IEEE, Venice, pp 261–266Wesenberg H (2011) Enterprise modeling in an agile world. In: Johannesson P, Krogstie J, Opdahl AL (eds) The practice of enterprise modeling (PoEM 2011). LNBIP 92. Springer, Heidelberg, pp 126–130Zdravkovic J, Stirna J, Henkel M, Grabis J (2013) Modeling business capabilities and context dependent delivery by cloud services. In: Proceedings advanced information systems engineering (CAiSE 2013). LNCS 7908. Springer, Heidelberg, pp 369–38
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