A contribution to the availability of lunar resources for powered construction

The use of lunar resources to construct solar power satellites wherein the resources are transported by a lunar mass driver is discussed. The minimization of cross track errors in the launch of payloads by mass driver is emphasized. The design and construction of the mass driver is outlined. Features of the proposed system addressed include passive magnetic damping, separation and snapout, and downrange correction

Sports anthropological and somatotypical comparison between female wrestlers and hapkidoin of different performance levels

The present study compares the anthropometry and somatotyping of 13 healthy female wrestlers (age range 15–26 years) and 30 hapkidoin (age range 20–44 years) of various performance categories.The hapkidoin of higher performance levels are 5 cm larger on average than the wrestlers and the hapkidoin of the lower class. In almost all circumferences the wrestlers achieve higher values than the Hapkidoin. For most circum ferences and skinfolds, significantly higher values in the higher weight classes are observed in the wrestlers. The BMI of all examined athletes is in the normal range. In the constitution typology after Conrad (1963), the wrestlers appear to be leptomorph-metroplastical, the hapkidoin appear to be leptomorph-hypoplastical.In the Cartesian coordinate system after Knußmann, the representatives of both martial arts disciplines are macrosom and superleptomorph, i.e. muscular, tall and slender. In the somatochart after Heath & Carter (1967), the average type of the hapkidoin is 7 – 2 – 2, that of the wrestlers is 6 – 1 – 2. These somatotypes are much stouter and less muscular than the martial arts somatotypes in the study of Gualdi-Russo et al. (1993). From this observation we can infer a considerable development potential of the examined sportswomen in our study

Towards robust aero-thermodynamic predictions for re-usable single-stage to orbit vehicles

Re-usable single stage to orbit launch vehicles promise to reduce the cost of access to space, but their success will be particularly reliant on accurate and robust modelling of their aero-thermodynamic characteristics. For preliminary design and optimization studies, relatively simple numerical prediction techniques must perforce be used, but it is important that the uncertainty that is inherent in the predictions of these models be understood. Predictions of surface pressure and heat transfer obtained using a new reduced-order model that is based on the Newtonian flow assumption and the Reynolds analogy for heating are compared against those of a more physically-sophisticated Direct Simulation Monte Carlo method in order to determine the ability of the model to capture the aero-thermodynamics of vehicles with very complex configuration even when run at low enough resolution to be practical in the context of design optimization studies. Attention is focused on the high-altitude regime where lifting re-usable Single-Stage to Orbit configurations will experience their greatest thermal load during re-entry, but where non-continuum effects within the gas of the atmosphere might be important. It is shown that the reduced-order model is capable of reproducing the results of the more complex Monte Carlo formalism with surprising fidelity, but that residual uncertainties exist, particularly in the behaviour of the heating models and in the applicability of the continuum assumption given the onset of finite slip velocity on surface of vehicle. The results suggest thus that, if used with care, reduced-order models such as those described here can be used very effectively in the design and optimization of space-access vehicles with very complex configuration, as long as their predictions are adequately supported by the use of more sophisticated computational techniques

Light curves and colours of the faint Uranian irregular satellites Sycorax, Prospero, Stephano, Setebos and Trinculo

After the work of Gladman et al. (1998), it is now assessed that many irregular satellites are orbiting around Uranus. Despite many studies have been performed in past years, very few is know for the light-curves of these objects and inconsistencies are present between colours derived by different authors. This situation motivated our effort to improve both the knowledge of colours and light curves. We present and discuss time series observations of Sycorax, Prospero, Stephano, Setebos and Trinculo, five faint irregular satellites of Uranus, carried out at VLT, ESO Paranal (Chile) in the nights between 29 and 30 July, 2005 and 25 and 30 November, 2005. We derive light curves for Sycorax and Prospero and colours for all of these these bodies. For Sycorax we obtain colours B-V =0.839 +/- 0.014, V-R = 0.531 +/- 0.005 and a light curve which is suggestive of a periodical variation with period about 3.6 hours and amplitude about 0.067 +/- 0.004 mag. The periods and colours we derive for Sycorax are in agreement with our previous determination in 1999 using NTT. We derive also a light-curve for Prospero which suggests an amplitude of about 0.2 mag and a periodicity of about 4 hours. However, the sparseness of our data, prevents a more precise characterization of the light-curves, and we can not determine wether they are one-peaked or two-peaked. Hence, these periods and amplitudes have to be considered preliminary estimates. As for Setebos, Stephano and Trinculo the present data do not allow to derive any unambiguous periodicity, despite Setebos displays a significant variability with amplitude about as large as that of Prospero. Colours for Prospero, Setebos, Stephano and Trinculo are in marginal agreement with the literature.Comment: Submitted to A&A 13 Dec 2006, Accepted 17 Apr 2007. 18 pages, 8 colours figures BW printable, 6 tables. LaTeX 2.09, with packages: natbib, graphicx, longtable, aa4babbage included in the submission file (tar gzipped of 349 KBytes

Untersuchungen zur Expression potentiell allergierelevanter Gene

Asthma bronchiale ist eine chronische Atemwegsentzündung. Der Körper reagiert auf ein harmloses Antigen mit einer Überreaktion des Immunsy- stems was zu einer Atemwegshyperreagibilität und einer chronischen Ent- zündung in den Atemwegen führt. Diese Immunantwort ist Th2-dominiert und die Zytokine der Th2-Zellen spielen eine wichtige Rolle in der Pathogenese des Asthma. Therapiert wird diese Krankheit überwiegend mit Cortison als Entzündungshemmer und ß2-Mimetika als Bronchodilatatoren. Diese Behandlung ist symptomatisch und beherrscht leider nicht alle Formen des Asthma bronchiale. Außerdem hat die Therapie mit Cortison aufgrund seiner weitgefächerten Wirkungsweise viele Nebenwirkungen. Neuere Therapieansätze setzen auf die zentrale Rolle der Th2-Zellen in der Pathogenese des Asthma. Bisher konnten mit der Unterdrückung der bekannten Th2-Zytokine noch keine größeren Erfolge verzeichnet werden. Um einen neuen, eventuell kurativen Therapieansatz zu finden, wurden in dieser Arbeit noch unbekannte Gene untersucht, deren Genexpression in pulmonalen T-Lymphozyten von Mäusen mit chronischem Asthma stärker exprimiert werden als in pulmonalen T-Lymphozyten von Mäusen mit akutem Asthma. Im ersten Schritt dieser Arbeit wurde mittels quantitativer PCR bewiesen, dass ein Expressionsanstieg der Gene 1, 2, 3, 5 von pulmonalen T-Lymphozyten gesunder Tiere, über die pulmonalen T-Lymphozyten der Tiere mit akutem Asthma zu den pulmonalen T-Lymphozyten der Tiere mit chronischem Asthma besteht. Eine Beteiligung an der Chronifizierung und Pathogenese des Asthma scheint somit möglich. Um die Nebenwirkungen zu minimieren, sollte die Expression von Genen, die therapeutisch beeinflusst werden, möglichst eine hohe Organ- bzw. Zellselektivität aufweisen. In einem zweiten Schritt wurde daher die Expression der Gene mittels qualitativer PCR in verschiedenen Organen der gesunden Maus untersucht. Eine besonders starke Expression fand sich im Lymphknoten, was auf eine hohe Expression in differenzierten T-Lymphozyten hinweist. Aber auch die anderen Organe exprimierten die unbekannten Gene schwach. Während einige dieser Organe lymphatisches Gewebe und damit differenzierte T-Lymphozyten enthalten (z.B. Darm) konnte die basale Ex- pression einiger anderer Organe (z.B. Hoden) nicht durch das Vorhanden- sein von T-Lymphozyten erklärt werden. In einem dritten Schritt wurde die Genexpression in murinen Zelllinien mittels quantitativer PCR gemessen. Auffällig war die hohe Expression der Gene 1-5 in der Epithelzelllinie LA-4. Diese Expression könnte die basale Expression in epithelialen Organen erklären. EL-4 als T-Lymphozytenlinie zeigte allerdings nicht die erwartete höchste Expression. Dies könnte auf eine selektiv erhöhte Expression der unbekannten Gene in differenzierten T-Lymphozyten hinweisen. Insgesamt lässt sich feststellen, dass die weitere Erforschung der Gene 1,2,3 und 5 weiterhin von Interesse ist, da diese einen eindeutigen Expressionsanstieg in T-Lymphozyten von chronisch asthmatischen Mäusen zeigen. Für Gen 4 konnte kein detektierbarer Expressionsanstieg gemessen werden. Ob die genannten Gene jedoch als therapeutische Angriffspunkte geeignet wären, bleibt aufgrund ihrer ubiquitären Expression ungewiss. Interessant bleibt zu erfahren, welche Funktion diese Gene inne haben, und ob durch die Blockade dieser Gene die Chronifizierung von Asthma bronchiale zu beeinflussen ist. Hierbei sind weitere Versuche mit selektiver Inhibition der Expression dieser Gene angezeigt

Formation of Protoplanets from Massive Planetesimals in Binary Systems

More than half of stars reside in binary or multiple star systems and many planets have been found in binary systems. From theoretical point of view, however, whether or not the planetary formation proceeds in a binary system is a very complex problem, because secular perturbation from the companion star can easily stir up the eccentricity of the planetesimals and cause high-velocity, destructive collisions between planetesimals. Early stage of planetary formation process in binary systems has been studied by restricted three-body approach with gas drag and it is commonly accepted that accretion of planetesimals can proceed due to orbital phasing by gas drag. However, the gas drag becomes less effective as the planetesimals become massive. Therefore it is still uncertain whether the collision velocity remains small and planetary accretion can proceed, once the planetesimals become massive. We performed {\it N}-body simulations of planetary formation in binary systems starting from massive planetesimals whose size is about 100-500 km. We found that the eccentricity vectors of planetesimals quickly converge to the forced eccentricity due to the coupling of the perturbation of the companion and the mutual interaction of planetesimals if the initial disk model is sufficiently wide in radial distribution. This convergence decreases the collision velocity and as a result accretion can proceed much in the same way as in isolated systems. The basic processes of the planetary formation, such as runaway growth and oligarchic growth and final configuration of the protoplanets are essentially the same in binary systems and single star systems, at least in the late stage where the effect of gas drag is small.Comment: 26pages, 11 figures. ApJ accepte

Planetesimal collisions in binary systems

We study the collisional evolution of km-sized planetesimals in tight binary star systems to investigate whether accretion towards protoplanets can proceed despite the strong gravitational perturbations from the secondary star. The orbits of planetesimals are numerically integrated in two dimensions under the influence of the two stars and gas drag. The masses and orbits of the planetesimals are allowed to evolve due to collisions with other planetesimals and accretion of collisional debris. In addition, the mass in debris can evolve due to planetesimal-planetesimal collisions and the creation of new planetesimals. We show that it is possible in principle for km-sized planetesimals to grow by two orders of magnitude in size if the efficiency of planetesimal formation is relatively low. We discuss the limitations of our two-dimensional approach.Comment: 5 pages, 5 figures, accepted for publication in MNRA

Dynamics of Planetesimals due to Gas Drag from an Eccentric Precessing Disk

We analyze the dynamics of individual kilometer-size planetesimals in circumstellar orbits of a tight binary system. We include both the gravitational perturbations of the secondary star and a non-linear gas drag stemming from an eccentric gas disk with a finite precession rate. We consider several precession rates and eccentricities for the gas, and compare the results with a static disk in circular orbit. The disk precession introduces three main differences with respect to the classical static case: (i) The equilibrium secular solutions generated by the gas drag are no longer fixed points in the averaged system, but limit cycles with frequency equal to the precession rate of the gas. The amplitude of the cycle is inversely dependent on the body size, reaching negligible values for $\sim 50$ km size planetesimals. (ii) The maximum final eccentricity attainable by small bodies is restricted to the interval between the gas eccentricity and the forced eccentricity, and apsidal alignment is no longer guaranteed for planetesimals strongly coupled with the gas. (iii) The characteristic timescales of orbital decay and secular evolution decrease significantly with increasing precession rates, with values up to two orders of magnitude smaller than for static disks. Finally, we apply this analysis to the $\gamma$-Cephei system and estimate impact velocities for different size bodies and values of the gas eccentricity. For high disk eccentricities, we find that the disk precession decreases the velocity dispersion between different size planetesimals, thus contributing to accretional collisions in the outer parts of the disk. The opposite occurs for almost circular gas disks, where precession generates an increase in the relative velocities.Comment: 11 pages, 9 figures. Accepted in MNRA

Habitable Planet Formation in Binary-Planetary Systems

Recent radial velocity observations have indicated that Jovian-type planets can exist in moderately close binary star systems. Numerical simulations of the dynamical stability of terrestrial-class planets in such environments have shown that, in addition to their giant planets, these systems can also harbor Earth-like objects. In this paper, we study the late stage of terrestrial planet formation in such binary-planetary systems, and present the results of the simulations of the formation of Earth-like bodies in their habitable zones. We consider a circumprimary disk of Moon- to Mars-sized objects and numerically integrate the orbits of these bodies at the presence of the Jovian-type planet of the system and for different values of the mass, semimajor axis, and orbital eccentricity of the secondary star. Results indicate that, Earth-like objects, with substantial amounts of water, can form in the habitable zone of the primary star. Simulations also indicate that, by transferring angular momentum from the secondary star to protoplanetary objects, the giant planet of the system plays a key role in the radial mixing of these bodies and the water contents of the final terrestrial planets. We will discuss the results of our simulation and show that the formation of habitable planets in binary-planetary systems is more probable in binaries with moderate to large perihelia.Comment: 27 pages, 11 figures, submitted for publicatio