The quantum theory can be formulated in the language of positive functionals on Weyl or Clifford algebra (L-functionals). It is shown that this language gives simple understanding of diagrams of Keldysh formalism (that coincide in our case with the diagrams of thermo-field dynamics). The matrix elements of the scattering matrix in the formalism of L-functionals are related to inclusive cross-sections, therefore we suggest the name “inclusive scattering matrix” for this notion. The inclusive scattering matrix can be expressed in terms of on-shell values of generalized Green functions. This notion is necessary if we want to analyze collisions of quasiparticles.
The relation between open topological strings and Chern–Simons theory was discovered by Witten. He proved that A-model on T∗M where M is a three-dimensional manifold is equivalent to Chern–Simons theory on M and that A-model on arbitrary Calabi–Yau 3-fold is related to Chern–Simons theory with instanton corrections. In present Letter we discuss multidimensional generalization of these results.
Chemical processes that occur at the particle aqueous interface are properly termed colloidal when the particle is a material where one or more of its three dimensions lies within the range of 1–1000 nm. Nanoparticles which include porous materials and nanostructures that meet this requirement have been the subject of investigation from researchers from a variety of disciplines and their studies have been reported in the Journal of Colloid and Interface Science as well as other archival journals for many years. The chemical process of charge development on colloidal particles is, in general, determined by a plethora of complex physico-chemical properties of the particles surfaces exposed to the surrounding aqueous environment. The existence of surface charge plays an essential role in the dispersity, flocculation properties, ion exchange capacity, dissolution, and deposition of cations and anions of synthetic and natural materials. In particular, recent advances in catalytic science have demonstrated that the “black art” of catalyst preparation does have a scientific basis. The objective of this article is to demonstrate that surface charge development (a consequence of proton transfer) as a function of pH, the so-called master variable, can identify specific domains of charge maxima. It is found that the number and strength of charged sites can be correlated with the catalytic properties of the studied materials, even though the reaction conditions are significantly different from those under which the surface charge was measured. Such findings are essential for the establishment of design and construction protocols and prediction of the performance of catalysts.
A backscatter Kikuchi diffraction attachment to an SEM enables the convenient investigation of individual grain orientations on bulk surfaces. Their relation to microstructural features gives insight into many aspects of anisotropic materials properties. The formation of backscatter Kikuchi patterns and the experimental set-up for their acquisition are briefly outlined. The interactive and automated indexing of patterns and the fully Automated Crystal lattice Orientation Mapping (ACOM) with a computer-controlled SEM are presented in detail. Digital beam scan requires, as a consequence of the high tilt of the specimen with respect to the beam, current calculation of pattern centre and diffraction length (autocalibration) and dynamic focusing by the software. The automated measurement of lattice orientations takes less than half a second per image point on a Pentium Pro 200 MHz PC. Crystal lattice orientation maps (COM) are constructed by assigning to each grid point in the image a colour specific for the grain orientation, the misorientation or the grain boundary character. For a quantitative representation of the spatial distribution of microscale texture, an orientation-to-colour key is used by colour shading inverse pole figures, sections through Euler space or sections through Rodrigues orientation space. Texture components of interest can be highlighted by distinct colours in order to reveal textural inhomogeneities. Typical applications are given.
DOI : 10.1016/S0968-4328(97)00010-3 Anahtar Kelimeler :
backscatter Kikuchi pattern, BKP, BKD, EBSD, crystal texture, ACOM, OIM, grain boundary, phase discrimination, ACOM, Automated Crystal lattice Orientation Mapping/Measurement, COM, Crystal lattice Orientation Map, BKD, Backscatter Kikuchi Diffraction, BKP, Backscatter Kikuchi diffraction Pattern, CBED, Convergent Beam Electron Diffraction, EBSD, Electron BackScatter Diffraction (= BKD usually SEM version using a video camera for recording the pattern), EBSP, Electron BackScatter Pattern (= BKP), ECP, Electron Channelling Pattern, LEED, Low Energy Electron Diffraction, MBD, Micro Beam electron Diffraction, MODF, MisOrientation Distribution Function, ODF, Orientation Distribution Function, OIM™, Orientation Image Microscopy (= ACOM), OIM™, is a trade mark of TexSEM Lab. Inc., Heber City, Utah/USA, ORKID, Orientation from KIkuchi Diffraction, RHEED, Reflection High Energy Electron Diffraction, SAD, Selected Area electron Diffraction, SEM, Scanning Electron Microscope / Microscopy, STEM, Scanning Transmission Electron Microscope / Microscopy, ϵ, value reciprocal value of the fraction of the coincident lattice sites of two superimposed crystal lattices, TEM, Transmission Electron Microscope / Microscopy, TKP, Transmission Kikuchi diffraction Pattern
Cilt: 28 Sayı: 3 Sayfa: 249-265 ISSN: 0968-4328
Obwohl von immer mehr zunehmender Bedeutung, gibt es bisher zur Versorgung von chronischen Wunden und detaillierten Aspekten der Wundreinigung noch keine KRINKO-Empfehlung. Stattdessen finden sich Fragmente in verschiedenen vom RKI herausgegebenen Empfehlungen. Diese werden zu einem möglichen Standard zusammengeführt. Dabei wird auf fachlicher und rechtlicher Basis festgelegt, dass die Wunde im Falle einer mechanischen Reinigung immer aus der Wunde heraus zu reinigen ist und nicht, wie bisher oft gelehrt, bei septischen Wunden in die Wunde hinein.
We define a superspace over a ring R as a functor on a subcategory of the category of supercommutative R-algebras. As an application the notion of a p-adic superspace is introduced and used to give a transparent construction of the Frobenius map on p-adic cohomology of a smooth projective variety over Zp (the ring of p-adic integers).
We construct explicity the subspace in the infinite dimensional grassmannian corresponding to the τ-function of the 2D topological gravity. This allows us to give a simple proof of some conjectures on the equations defining this function.
Over the years, Information Technology (IT) has struggled with how to create an effective structure and processes. It is our main thesis that if organizations focused more on implementing a sound IT governance strategy, it might help senior executives to manage not only the IT-related activities, but also the perceptions between IT and the rest of the organization, and, in doing so, foster a more successful IT organization. Using six case studies conducted within the oil and gas industry, we explore differences in perceptions toward IT and in the organization of IT activities. Using an Extended Platform Logic Perspective, we note differences and similarities between the firms, with respect to IT capabilities, relational and integration mechanisms, measures of success, and relationships with the business units. Our results suggest that our colleagues-in-practice have evolved from focusing on one-way architectures within a centralization/decentralization context toward a two-way relationship-oriented approach to managing the IT structure. We conclude by offering some thoughts on how IT executives can help to shape perceptions of IT within their firms and explore how academics can begin to help our colleagues-in-practice as they struggle with the governance of the IT function.
DOI : 10.1016/S0963-8687(03)00021-0 Anahtar Kelimeler :
Information Technology Management, Oil and gas industry, Governance Platform Logic Model Relation-Based Management
Cilt: 12 Sayı: 2 Sayfa: 129-166 ISSN: 0963-8687
Fußpilz gehört inzwischen zu den häufigsten Infektionskrankheiten in Deutschland. Insbesondere Senioren leiden mit zunehmendem Alter unter Haut- und Nagelmykosen. Die früher als Arzneimittel verfügbaren Fußpilzprophylaktika sind gänzlich verschwunden. Die Gründe liegen weniger an einer mangelhaften Wirksamkeit dieser Präparate als vielmehr an der früher oft erfolgten Fehlanwendung und einem erschwerten Zulassungsverfahren. Prophylaxemaßnahmen sollten bereits im Kindesalter und mit der Auswahl geeigneten Schuhwerkes beginnen und mit der Anwendung geeigneter Flächendesinfektionsmaßnahmen und Fußantiseptika enden.
A quantitative model has been developed to improve the prediction of the occurrence of marine siliciclastic source rocks and their likely organic carbon content. The input parameters of this quantitative model are: organic matter supply in the surface layer of the ocean (photic zone); water depth (calculation of the carbon flux); sedimentation rate; and preservation conditions (presence or absence of oxygen at the sediment-water interface). To handle the difficulties in the quantification of input parameters a probabilistic approach is applied. Depending on the available data or the interpretation of the kind of environment, different risk distribution functions are used to describe the possible range of each input parameter. The calculation is then carried out using the Monte Carlo simulation technique, resulting in a probability distribution of the total organic carbon content which forms the basis of the analysis. Different scenarios currently under debate, e.g. high primary productivity or the possible effects of enhanced preservation under anoxic bottom water conditions and the influence of varying water depth and sedimentation rate, can be tested very quickly. Using examples of recent (Peru continental margin) and ancient (Lower Toarcian Shale, Germany) organic-rich, marine shales, the potential of this tool is demonstrated, firstly to quantify souce rock quality (in this case total organic carbon content only), secondly to assess quantitatively the uncertainties in source rock prediction (e.g. evaluation of organic matter supply, water depth and sedimentation rates) and thirdly to determine source quality risk values to be used in the appraisal of sedimentary basins and prospects.
The Gifhorn Trough in North Germany contains an interbedded succession of Lower to Middle Jurassic source and reservoir rocks. Regional variations in the burial history made it possible to investigate different stages in the maturation history of source rocks and the diagenetic history of reservoir rocks. This study focuses in particular on the temporal and spatial relation between secondary petroleum migration and diagenetic events in the reservoir sandstones. Reconstruction of the burial and geothermal history indicate the initiation of petroleum generation at the beginning of the Upper Cretaceous. Lower Toarcian shales have been identified as the common source rock of all oils, based on biomarker and stable isotope studies. Differences in the composition and maturity of reservoired oils are interpreted to be related to separated oil kitchens of different maximum source rock maturity, rather than in-reservoir alteration after migration and accumulation.
The local exact and approximate solutions of the adsorption integral equation are presented. The Langmuir-like adsorption isotherm is assumed as a kernel. The exact local solution is compared with Sips method. The accuracy and resolution of truncated approximations are discussed. The influence of experimental temperature on calculated results is also considered. Lateral interactions are taken into account for the random topography model of the adsorption sites.
Firms often set long notice periods when consumers cancel a contract, and sometimes do so even when the costs of changing or canceling the contract are small. We investigate a model in which a firm offers a contract to consumers who may procrastinate canceling it due to naive present-bias. We show that the firm may set a long notice period to exploit naive consumers.
Recent studies investigate policies motivating consumers to make an active choice as a way to protect unsophisticated consumers. We analyze the optimal timing of such choice-enhancing policies when a firm can strategically react to them. In the model, a firm provides a contract with automatic renewal. We show that a policy intending to enhance consumers’ choices when they choose a contract can be detrimental to welfare. By contrast, a choice-enhancing policy at the time of contract renewal increases welfare more robustly. Our results highlight that policies should be targeted in timing to the actual choice inefficiency.