Distinguishing damages from two earthquakes —Archaeoseismology of a Crusader castle (Al-Marqab citadel, Syria)

Damages from two major earthquakes are identified in medieval Al-Marqab citadel (Latin: Margat) in coastal Syria. Built by the Order of St. John (Hospitallers) in the twelfth–thirteenth centuries, the hilltop fortification has masonry walls made with and without mortar, using the opus caementum technology (Roman concrete). V-shaped and U-shaped failures, single-corner and symmetrical corner collapses, and in-plane shifts of ashlar masonry walls are identified and dated by historical and archaeological methods. The azimuth of displacement is NE-SW for the older damages of the Crusader period (A.D. 1170–1285), possibly related to the A.D. 1202 earthquake. A later, NW-SE displacement occurred during the Muslim period (post- 1285). The 1202 earthquake produced at least VIII intensity on the MSK scale at Al-Marqab, which is higher than previously considered

al-Marqab kutatási program - a történeti források = al-Marqab Research Project - the Historical Sources

Az al-Marqab történeti forrásait vizsgáló kutatás a térség egyik legnagyobb keresztes erődítésében öt éve folyó magyar vezetésű multidiszciplináris kutatási program egyik legfontosabb pillérét alkotta. A régészeti és más tudományos kutatási módszerekkel kiegészített forráskutatás révén megtörtént a vár helyiségeinek azonosítása és az azokban feltárt régészeti emlékanyag tanulmányozása révén teljesebb képet kapni a középkori életről és technológiáról, mely bizonyos esetekben (pl. a vízgazdálkodás vagy a hadiépítészeti elemek) meghaladta a korábban e téren fejlettebbnek hitt muszlim világ technikai színvonalát is. Az egyéb területeken (pl. falképek, étkezés…stb) végzett munkák eddigi eredményeiből kitűnik, hogy bár a Szentföld fontos területe volt a kulturális kölcsönhatásnak, a latin államok egyik legfontosabb támaszpontjának lakói erősen ragaszkodtak az európai gyökerekhez és tradíciókhoz. A korabeli európai technikai színvonalat meghaladó újításaik jelentős része nem közvetlen átvétel volt a környező civilizációktól, hanem a speciális környezet által kiváltott saját fejlesztés, ami esetenként még a környező muszlim államok technológiai fejlettségi szintjét is meghaladta. A kutatás eredményei egyben jelentősen finomítják a keresztes háborúk koráról kialakított egyoldalúan negatív történelmi képet is, hiszen al-Marqab 12-13. századi történelme során inkább volt a környező vidék közigazgatási központjaként és gazdasági motorjaként funkcionáló város, mint aktív katonai központ. | The research of the historical sources concerning al-Marqab formed one of the most important pillars of the Hungarian led multi-disciplinary research program in one of the largest castles of the Near-East. Data derived from the historical sources and supplemented with archaeological and other sources enabled us to identify the functions of the different areas of al-Marqab and the material retrieved from the excavations gave a detailed picture on the medieval life and technology. Research done on other subjects (eg. fresco research, medieval diet) showed that although the Holy Land was an important place of cultural exchange in the contemporary world, its inhabitants were clung strongly to their European roots and traditions. Many of their innovations stimulated by the special environment and exceeding contemporary European technological standards were not copied from the neighbouring civilizations, but were developments of their own. Some of these (eg. water management) even transcended the level of technological knowledge in the Muslim states traditionally seen as superiors to contemporary Europe. Results of this multi-disciplinary research spearheaded by the work on the historical sources can at the same time considerably clarify the usually one sided, negative picture on the age of the Crusades. For most of its 12th and 13th century history al-Marqab was rather the administrative centre and economic motor of the surrounding countryside than an active military centre

In Situ Synthesis of a Wear Resistant Layer on the Surface of Low Carbon Steel produced by Laser Melt Injection Technology

Titanium and his compounds are one of the most frequently used reinforcing particles in iron – ceramic composite materials. These materials will possess special characteristics because they are quenchable, their hardness can be increased by heat treatment and they can be quite easily machined. The point of the technology developed in the Bay Zoltán Institute of Materials Sciences and Technology is to form the reinforcing layer on the surface of the sample in an in situ way by melting the surface of the low carbon steel and the laminar carbon felt using laser beam while the titanium metal powder is simultaneously added to the melt. Several methods (metallographic examinations, selective area hardness measurements, SEM, and XRD) were applied to answer the questions about the optimal conditions for the in situ synthesis of a wear resistant layer

The three-dimensional carrier-envelope-phase map of focused few-cycle pulsed Gaussian beams

We derive an analytical expression that describes the complete three-dimensional carrier-envelope phase (CEP) distribution of in the focal volume of ultrashort pulsed Gaussian beams focused by spherical mirrors or lenses. The focal CEP map depends on the so-called factor $g$ specifying the frequency-dependence of the beam width of the source few-cycle pulse, on its chirp and on the small chromatic aberration introduced by a lens without appreciably distorting or broadening the few-cycle pulse. We show how to tailor the CEP map of mirror-focused and lens-focused few-cycle pulses in order to produce negligible transversal and axial CEP variations in specific regions of the focal volume for phase-sensitive interactions of light with matter taking place in a volume or on a surface. We propose a quasi-achromatic doublet lens that can implement in practice these tailored CEP distributions.Comment: 9 pages, 6 figure

Két földrengés Szíriában – Margat várának archeoszeizmológiája

Két nagyobb, egymásra következő földrengés által okozott sérüléseket azonosítottunk Margat (arabul al-Marqab) keresztes várában, Szíria tengerparti régiójában. A Szent János-lovagrend (johannita lovagok) által a 12–13. században emelt erődítmény erős kőfalakból áll, melyet az opus caementum (római beton) technológiájával építettek. V- és U-alakú falsérülések, egyoldali és szimmetrikus sarokomlások, valamint a falak megnyúlása történeti és régészeti módszerekkel datálhatóak. A keresztes időszakra (Kr. u. 1170–1285) datált idősebb sérülések ÉK-DNy rezgés következtében keletkeztek, valószínűleg az 1202-es földrengés következtében. Az 1285-ben kezdődött muzulmán uralom idején keletkezett sérülések ÉNy-DK rezgésirányról tanúskodnak. A libanoni Baalbekben kipattant 1202-es földrengés >VIII MSK intenzitást eredményezett Margatban; ez magasabb az eddigi feltételezett értéknél

Extended model for optimizing high-order harmonic generation in absorbing gases

We report on an extended version of the one-dimensional model proposed by Constant et al (1999 Phys. Rev. Lett. 82 1668) to study phase matching of high-order harmonic generation in absorbing and dispersive medium. The model-expanded from zeroth to first order-can be used with media having a pressure profile varying linearly with propagation length. Based on the new formulas, the importance of having a generation medium that ends abruptly with a steep pressure gradient for achieving high flux is highlighted. In addition to further rule-of-thumb guidelines for harmonic-flux optimization, it is shown that having a steep increase of pressure in the beginning of the medium increases harmonic flux, while it also decreases the required medium length to reach the absorption-limited maximum

Phase and polarization changes of pulsed Gaussian beams during focusing and propagation

The main goal of this thesis is to study the phase and polarization-state changes of focused, pulsed Gaussian beams upon focusing and propagation. An important topic of the work is the phase and group velocity of focused beams. Related to these properties, special attention is paid to the carrier-envelope phase variations of focused, pulsed beams in the vicinity of focus. An other appointed goal of this study is to examine the influence of focusing, as a diffraction effect, along with that of beam distortions (truncation, chromatic aberration, monochromatic aberrations - spherical aberration, astigmatism, coma, curvature of field, distortion) on the phase properties in the focus. A relevant topic assigned for examination is the time-dependent polarization state of short pulses, specifically to investigate if it changes upon focusing and free-space propagation, and if yes, how

The effect of plasma-core induced self-guiding on phase matching of high-order harmonic generation in gases

In this work we numerically study a self-guiding process in which ionization plays a dominant role and analyze its effect on high-order harmonic generation (HHG) in gases. Although this type of self-guiding --- termed as plasma-core induced self-guiding in previous works --- limits the achievable cut-off by regulating the intensity of the laser beam, it provides favorable conditions for phase matching, which is indispensable for high-flux gas high-harmonic sources. To underline the role of self-guiding in efficient HHG, we investigate the time-dependent phase matching conditions in the guided beam and show how the spatio-temporally constant fundamental intensity contributes to the constructive build-up of the harmonic field in a broad photon-energy range up to the provided cut-off.Comment: 14 pages, 7 figure