Stalemate and 'DTS' depth to stalemate endgame tables

Stalemating the opponent in chess has given rise to various opinions as to the nature of that result and the reward it should properly receive. Here, following Lasker and Reti, we propose that ‘stalemate’ is a secondary goal, superior to a draw by agreement or rule – but inferior to mate. We report the work of ‘Aloril’ who has created endgame tables holding both ‘DTM’ depth to mate and ‘DTS’ depth to stalemate data, and who should be regarded as the prime author of this paper. Further, we look at the classification of ‘Chess Stalemate Studies’ in the context of a ‘Lasker Chess’ which recognises the stalemate goal

FinalGen revisited: new discoveries

Romero’s FINALGEN of 2012 creates designer endgame tables for specific chess positions that feature no more than one non-pawn piece per side. Larger hard discs and faster solid-state discs have extended the reach of this software and encouraged its greater use. Some new discoveries illustrate here what is now feasible and how FINALGEN may be combined with other tools to reach definitive and likely truths

Calculation of sub-surface-initiated fatigue fractures in gears

Power-transmitting gears are typically heat-treated, most often case-hardened, to improve the fatigue strength and therefore to ensure higher fatigue life. The heat treatment causes higher hardness in the surface area as well as compressive residual stresses in the hardened layer. The near-surface compressive residual stresses are compensated by tensile stresses in higher depths of the gear volume. Pitting and tooth root breakage are the most common failure modes of gears, which are well researched and are also addressed in ISO 6336 [14]. The assessment of these failure modes provides the basis for the dimensioning of gears in the design phase. However, subsurfaceinitiated failures, like tooth flank fracture (TFF), can also appear at loads below the allowable level of loading for pitting and tooth root bending. TFF is a fatigue damage with crack initiation in the region of the transition between compressive and tensile residual stresses and usually leads to a total loss of drive. The existing calculation models for fatigue strength of gears with regard to TFF consider residual stresses differently. The base of the investigated calculation models is a local comparison of the occurring stresses and the strength value in the gear volume. The outcome of the calculation model from Oster [26] is highly influenced by the residual stress state. However, the material-physical model by Hertter [10] is more tolerant to slightly varying residual stresses. Further approaches such as Weber [34] and Konowalcyk [18] are based on the ideas of Oster and Hertter. The verification of the models is complicated due to the lack of residual stress measurements in larger depths under the gear flank surface. For example, residual stress measurement by Xray diffraction is only possible up to depths of approximately one millimeter. Therefore, tensile residual stresses in the inner tooth volume are considered zero in the common residual stresses calculation of Lang [19] and are not considered in the current calculation approach of ISO/DTS 6336-4 [15]. The paper describes local calculation approaches for the fatigue strength of gears with different consideration of residual stresses. Furthermore, the crack initiation point, which is mandatory for the validation of an approach, is examined. The failure mode TFF is hereby the key

Interpretation of X-ray Absorption Spectroscopy in the Presence of Surface Hybridization

X-ray absorption spectroscopy yields direct access to the electronic and geometric structure of hybrid inorganic-organic interfaces formed upon adsorption of complex molecules at metal surfaces. The unambiguous interpretation of corresponding spectra is challenged by the intrinsic geometric flexibility of the adsorbates and the chemical interactions with the interface. Density-functional theory (DFT) calculations of the extended adsorbate-substrate system are an established tool to guide peak assignment in X-ray photoelectron spectroscopy (XPS) of complex interfaces. We extend this to the simulation and interpretation of X-ray absorption spectroscopy (XAS) data in the context of functional organic molecules on metal surfaces using dispersion-corrected DFT calculations within the transition potential approach. On the example of X-ray absorption signatures for the prototypical case of 2H-porphine adsorbed on Ag(111) and Cu(111) substrates, we follow the two main effects of the molecule/surface interaction on XAS: (1) the substrate-induced chemical shift of the 1s core levels that dominates in physisorbed systems and (2) the hybridization-induced broadening and loss of distinct resonances that dominates in more chemisorbed systems.Comment: 13 pages, 4 figure

Rook versus Bishop

The focus here is on the influence of the endgame KRPKBP on endgames featuring duels between rook and bishop. We take advantage of the range of endgame tablebases and tools now available to ratify and extend previous analyses of five examples, including the conclusion of the justly famous 1979 Rio Interzonal game, Timman-Velimirović. The tablebases show that they can help us understand the hidden depths of the chess endgame, that the path to the draw here is narrower than expected, that chess engines without tablebases still do not find all the wins, and that there are further surprises in store when more pawns are added

Chess endgame news: the world chess championship, 2018

Computer analysis was very much to the fore in this, Carlsen’s most highly contested World Champion¬ship Match. It could be found on the web and in support of the various live commentaries on offer. Here, we focus on game six of the classic phase and game one of the rapid-tempo tie-break. More extensive analysis can be found in the e-repository version of this note

Double optical spring enhancement for gravitational-wave detectors

Currently planned second-generation gravitational-wave laser interferometers such as Advanced LIGO exploit the extensively investigated signal-recycling technique. Candidate Advanced LIGO configurations are usually designed to have two resonances within the detection band, around which the sensitivity is enhanced: a stable optical resonance and an unstable optomechanical resonance—which is upshifted from the pendulum frequency due to the so-called optical-spring effect. As an alternative to a feedback control system, we propose an all-optical stabilization scheme, in which a second optical spring is employed, and the test mass is trapped by a stable ponderomotive potential well induced by two carrier light fields whose detunings have opposite signs. The double optical spring also brings additional flexibility in reshaping the noise spectral density and optimizing toward specific gravitational-wave sources. The presented scheme can be extended easily to a multi-optical-spring system that allows further optimization

Ultraspurenbstimmung von Fluorbenzoesäuren in Hochsalinen Matrizes mittels massenspektrometrischer Isotopenverdünnungsanalyse

Im Rahmen dieser Disseration wurde eine Methode zum Nachweis von Fluorbenzoesäuren im Ultraspurenbereich in komplexen, wässrigen Probenmatrizes unter Verwendung der Iso- topenverdünnungsanalyse bei Einsatz von Gaschromatographie oder Ionenchromatographie mit massenselektiver Detektion entwickelt. Um mögliche Störeinflüsse der Probenmatrix zu minimieren und die Analyten gleichzeitig anzureichern, wurde eine zuvor von mir entwickelte Festphasenextraktion weiter optimiert und charakterisiert. Für die notwendige Auftrennung des Analytgemisches, welches aus der Festphasenextrak- tion erhalten wurde, wurden zwei chromatographische Methoden entwickelt. Im Fall der Gaschromatographie wurde eine Synthese entwickelt und optimiert, welche die quantitative Bildung der Methylester nach der SPE im Mikromaßstab durch Verwendung von BF3 · MeOH direkt im GC-Vial bei 64°C innerhalb von 24 Stunden ermöglicht. Erst die leichtflüchtigen Ester eignen sich für den Einsatz in der Gaschromatographie. Für ihre Trennung wurde eine GC-Säule mit Dimethylpolysiloxanfunktionalisierung mit 50 % Phenylanteil gewählt und ein Temperaturgradient zur bestmöglichen Trennung bei minimaler Laufzeit ausgearbeitet. Eine Charakterisierung der Fragmentierungsmuster nach Elektronenstoßionisation verhalf bei der anschließenden Erstellung einer SIM-Methode, um die instrumentelle Nachweisgrenze zu verbessern und den Matrixeinfluss weiter zu minimieren. Im Fall der Ionenchromatographie wurde nach einem Screening unterschiedlicher Trenn- säulentypen mit verschiedenen Funktionalisierungen und einem Vergleich verschiedener Eluentionen und -konzentrationen und Variation des Modifieranteil und der Trenntempe- ratur die optimale, isokratische Trennmethode ausgearbeitet. Der Einsatz einer 250 mm langen Trennsäule des Latex-Typs in Kombination mit einem 0,63 mM Natriumcarbona- teluent und 18% Acetonitril als organischem Modifier bei einer Säulentemperatur von 45°C ergab unter isokratischen Bedingungen die bestmögliche Trennung. Bei der zur massenselektiven Detektion nötigen Bildung von Ionen wurde die Elektrosprayionisation eingesetzt. Zur Charakterisierung des Ionisationsverhaltens der Säuren im Elektrospray und darauf aufbauend zur Verbesserung der instrumentellen Nachweisgrenze durch einen höchstmöglichen Ionisationsgrad wurden die Bedingungen hinsichtlich Kapillar- und Frag- mentorspannung und Sprayzusammensetzung untersucht. Die abschließende Entwicklung einer SIM-Methode analog zur Gaschromatographie komplettierte die Methodenentwick- lung und ergab eine höchstmögliche Empfindlichkeit bei simultaner Minimierung von Störeinflüssen. Zur Isotopenmarkierung von Fluorbenzoesäuren wurde eine kostengünstige und schnelle H/D-Austauschreaktion realisiert, die auf den Einsatz eines Katalysator verzichtet. Allein durch eine im Ölbad, Trockenschrank oder in der Synthesemikrowelle thermisch induzierte, elektrophile aromatische Substitution in konzentrierter D2SO4 gelang ein Austausch der aromatischen Protonen durch Deuterium. Am Beispiel von sechs Fluorbenzoesäuren wurden die Parameter Reaktionszeit und Reaktionstemperatur optimiert, um eine höchstmögliche Reinheit in einer Einzelreaktion bei einem minimalen Massenshift von +2 g/mol zu erreichen. Zum Abschluss wurde die Eignung der isotopenmarkierten Fluorbenzoesäuren in den einzel- nen Methodenteilen SPE, Veresterung mit BF3 ·MeOH, gaschromatographische Trennung, Elektronenstoßionisation, ionenchromatographische Trennung und Elektrosprayionisation geprüft und eine Isotopenverdünnungsanalyse in Realproben durchgeführt

Modelling of GPR Wave Propagation and Scattering in Inhomogeneous Media

Numerical modelling of GPR wave propagation is becoming more and more important. The ability to build complex models to mirror complex subsurface structures can improve our understanding of how electromagnetic waves are effected by it. The main task of this thesis was to develop a model generator which simplifies complex model building by applying statistical processes. Both, the distribution of inhomogeneities and random rough surfaces can be described statistically. The developed model builder \emph{modelGPR} uses Gaussian distribution to create rough surfaces and to embed inhomogeneities into a host medium. The potentials of the software are presented by two examples. The first is related to ground truth measurements for SAR-satellites in polar regions and the second is devoted to water detection in the Martian shallow subsurface