MAMA: An Algebraic Map for the Secular Dynamics of Planetesimals in Tight Binary Systems

We present an algebraic map (MAMA) for the dynamical and collisional evolution of a planetesimal swarm orbiting the main star of a tight binary system (TBS). The orbital evolution of each planetesimal is dictated by the secular perturbations of the secondary star and gas drag due to interactions with a protoplanetary disk. The gas disk is assumed eccentric with a constant precession rate. Gravitational interactions between the planetesimals are ignored. All bodies are assumed coplanar. A comparison with full N-body simulations shows that the map is of the order of 100 times faster, while preserving all the main characteristics of the full system. In a second part of the work, we apply MAMA to the \gamma-Cephei, searching for friendly scenarios that may explain the formation of the giant planet detected in this system. For low-mass protoplanetary disks, we find that a low-eccentricity static disk aligned with the binary yields impact velocities between planetesimals below the disruption threshold. All other scenarios appear hostile to planetary formation

Background free CARS imaging by phase sensitive heterodyne CARS

In this article we show that heterodyne CARS, based on a controlled and stable phase-preserving chain, can be used to measure amplitude and phase information of molecular vibration modes. The technique is validated by a comparison of the imaginary part of the heterodyne CARS spectrum to the spontaneous Raman spectrum of polyethylene. The detection of the phase allows for rejection of the non-resonant background from the data. The resulting improvement of the signal to noise ratio is shown by measurements on a sample containing lipid

Shot noise limited heterodyne detection of CARS signals

We demonstrate heterodyne detection of CARS signals using a cascaded phase-preserving chain to generate the\ud CARS input wavelengths and a coherent local oscillator. The heterodyne ampli¯cation by the local oscillator re-\ud veals a window for shot noise limited detection before the signal-to-noise is limited by amplitude °uctuations. We\ud demonstrate an improvement in sensitivity by more than 3 orders of magnitude for detection using a photodiode.\ud This will enable CARS microscopy to reveal concentrations below the current mMolar range

Little Higgs Model Completed with a Chiral Fermionic Sector

The implementation of the little Higgs mechanism to solve the hierarchy problem provides an interesting guiding principle to build particle physics models beyond the electroweak scale. Most model building works, however, pay not much attention to the fermionic sector. Through a case example, we illustrate how a complete and consistent fermionic sector of the TeV effective field theory may actually be largely dictated by the gauge structure of the model. The completed fermionic sector has specific flavor physics structure, and many phenomenological constraints on the model can thus be obtained beyond gauge, Higgs, and top physics. We take a first look on some of the quark sector constraints.Comment: 14 revtex pages with no figure, largely a re-written version of hep-ph/0307250 with elaboration on flavor sector FCNC constraints; accepted for publication in Phys.Rev.

ПАРАДИГМА ПОЭТИЧЕСКОГО ВООБРАЖЕНИЯ В РАННЕМ ТВОРЧЕСТВЕ А. ДЕ ЛАМАРТИНА (анализ творческой концепции в традиции Г. Башляра)

В статье ранние произведения А. де Ламартина рассматриваются в аналитической традиции Г. Башляра. Стихотворения, написанные под влиянием Ж.Ж. Руссо в новой мифопоэтической форме, стали романтической актуализацией стихии человеческих переживаний в их связи со стихиями природы и трансендентным бытием

Beyond internet as tool: A mixed-methods study of online drug discussion

This thesis describes how internet use has shaped drug practices among Australians who engage in the recreational use of psychostimulants and hallucinogens (‘party drugs’) and participate in public internet forums. This thesis uniquely contributes to drugs research by applying theoretical frameworks from internet studies, finding that internet forums enable the consumption and production of drug information, facilitate the production of alternative online places, and are increasingly converged with offline social worlds

The monoid of queue actions

We investigate the monoid of transformations that are induced by sequences of writing to and reading from a queue storage. We describe this monoid by means of a confluent and terminating semi-Thue system and study some of its basic algebraic properties, e.g., conjugacy. Moreover, we show that while several properties concerning its rational subsets are undecidable, their uniform membership problem is NL-complete. Furthermore, we present an algebraic characterization of this monoid's recognizable subsets. Finally, we prove that it is not Thurston-automatic

Ecomat und Dammkultur – Alternative Bodenbearbeitungssysteme im Ökologischen Landbau – Erste Ergebnisse aus einem Exaktversuch

In the interdisciplinary research project a field experiment of alternative tillage systems in organic farming was installed. Ridge till system from Turiel-Major and Ecomat-system from Kverneland will be compared with conventional ploughing system. Within the project, located on the experimental farm of the University of Kassel, regular yearly workshops are led. Due to the regular contact with farmers, advisers, developers and scientists knowledge of practice will be carried into scientific research, the transfer of knowledge will be carried on. The change to the Ecomat-system is simple. Take notice that after very shallow till-age, like stubble cultivation (short stubble) or turning grass-clover, the following tillage has to be done a few cm deeper. In the year of implementing the Ecomat-system there were no decreases in yields. The mineralization of Nitrogen was the same as in the ploughing system. When changing to the ridge till system the width of the dams (90 cm) must fit to the track width, planting and harvesting equipment. After stubble cultivation in the ridge till system mineralization of N increased. This N was taken up by the catch crop. Leaching of N is not expected. Even in the first year after changing the tillage systems the alternative systems Eco-mat and ridge till showed higher saturated hydraulic conductivity than the conventional ploughing system. This leads to much lower susceptibility of soil erosion when using these soil layer conservation systems