Rotation of Hot Horizontal Branch Stars in Galactic Globular Clusters

We present high resolution UVES+VLT spectroscopic observations of 61 stars in the extended blue horizontal branches of the Galactic globular clusters NGC 1904 (M79), NGC 2808, NGC 6093 (M80), and NGC 7078 M15). Our data reveal for the first time the presence in NGC 1904 of a sizable population of fast (v sin(i) >= 20 km/s) horizontal branch (HB) rotators, confined to the cool end of the EHB, similar to that found in M13. We also confirm the fast rotators already observed in NGC 7078. The cooler stars (T_eff < 11,500 K) in these three clusters show a range of rotation rates, with a group of stars rotating at ~ 15 km/s or less, and a fast rotating group at ~ 30 km/s. Apparently, the fast rotators are relatively more abundant in NGC 1904 and M13, than in NGC 7078. No fast rotators have been identified in NGC 2808 and NGC 6093. All the stars hotter than T_eff ~ 11,500 K have projected rotational velocities vsini< 12 km/s. The connection between photometric gaps in the HB and the change in the projected rotational velocities is not confirmed by the new data. However, our data are consistent with a relation between this discontinuity and the HB jump.Comment: 2 pages, 1 figure, A.S.P. Conf. Ser., in press in Vol. 296, 200

Electron-Phonon Coupling Origin of the resistivity in YNi_{2}B_{2}C Single Crystals

Resistivity measurements from 4.2 K up to 300 K were made on YNi_{2}B_{2}C single crystals with Tc=15.5 K. The resulting rho(T) curve shows a perfect Bloch-Grueneisen (BG) behavior, with a very small residual resistivity which indicates the low impurity content and the high cristallographic quality of the samples. The value lambda_{tr}=0.53 for the transport electron-phonon coupling constant was obtained by using the high-temperature constant value of d(rho)/dT and the plasma frequency reported in literature. The BG expression for the phononic part of the resistivity rho_{ph}(T) was then used to fit the data in the whole temperature range, by approximating alpha^{2}_{tr}F(Omega) with the experimental phonon spectral density G(Omega) multiplied by a two-step weighting function to be determined by the fit. The resulting fitting curve perfectly agrees with the experimental points. We also solved the real-axis Eliashberg equations in both s- and d-wave symmetries under the approximation alpha^{2}F(Omega)= alpha^{2}_{tr}F(Omega). We found that the value of lambda_{tr} here determined in single-band approximation is quite compatible with Tc and the gap Delta experimentally observed. Finally, we calculated the normalized tunneling conductance, whose comparison with break-junction tunnel data gives indication of the possible s-wave symmetry for the order parameter in YNi_{2}B_{2}C.Comment: 6 pages, 5 figures. Proceedings of SATT10 Conference, to be published in Int. J. Mod. Phys.

Increasing of efficiency by VSM method in Behr Czech s.r.o. company Mnichovo Hradiště

katedra: KVS; přílohy: 1 CD ROM; rozsah: 42 s. (48 700 znaků)Theme of this work is production mapping in company Behr Czech. Mapping is focused on ET division that produces coolers for vans. Mapping has been done by using VSM (Value Stream Mapping). There have been made several adjustments compared to default methods. These adjustments are matching to standards of Behr Czech s.r.o. From VSM and collected data, there have been identified problems in production. Each problem has been analyzed, found its cause and proposed suitable measures to remove problem or lowers its influence to production.Tato bakalářská práce se zabývá mapováním výroby ve společnosti Behr Czech. Mapovanou výrobou je divize ET, výroba chladičů pro nákladní vozy. Mapování bylo prováděno pomocí metody VSM (Value Stream Maping ? český překlad: Mapování Hodnotového Toku). Při mapování byly použity úpravy oproti standardní metodice. Tyto úpravy odpovídají vnitřním standardů společnosti Behr Czech s.r.o. Pomocí VSM mapy a dat získaných při mapování byly identifikovány problémy ve výrobě. Jednotlivé problémy byly následně analyzovány, zjištěny jejich příčiny a navržena vhodná opatření k jejich odstranění popř. k minimalizaci jejich vlivu na výrobu

Heat Capacity study of β\beta-FeSi2_2 single crystals

Heat Capacity of needle-like [length=5mm, diameter=1 mm] $\beta$-FeSi$_{2}$ single crystal, grown by chemical vapor transport has been measured. Two anomalies are found, a broad deviation centered around 160 K and a clear deviation at a temperature of 255 K approximately. We have attempted to relate these to the anomalies previously reported in the case of the resistivity data. The Transient Thermoelectric Effect [TTE] results lead us to the inference that the system under goes from single carrier system to at least two carrier system at 220 K-our heat capacity results seem to provide further independent evidence for this transition in this system.Comment: 8 pages, 5 figure

Connecting Mathematics and the Applied Science of Energy Conservation

To effectively teach science in the elementary classroom, pre-service K-8 teachers need a basic understanding of the underlying concepts of physics, which demand a strong foundation in mathematics. Unfortunately, the depth of mathematics understanding of prospective elementary teachers has been a growing and serious concern for several decades. To overcome this challenge, a two-pronged attack was used in this study. First. students in mathematics courses were coupled with physical science courses by linking registration to ensure co-requisites were taken. This alone improved passing rates. Secondly, an energy conservation project was introduced in both classes that intimately tied the theoretical mathematics base knowledge to problems in physical science, energy efficiency, and household economics. These connections made the mathematics highly relevant to the students and improved both their theoretical understanding and their grades. Together, the two approaches of tying mathematics to physical science and applying mathematical skills to solving energy efficiency problems have shown to be extremely effective at improving student performance. This five-year study not only exhibited record improvements in student performance, but also can be easily replicated at other institutions experiencing similar challenges in training pre-service elementary school teachers

Smith, K. Meleesa (FA 906)

Finding aid for Folklife Archives Project 906. Project titled: “Superstitions in General.” Project includes note cards with brief descriptions of superstitions of informants from Florida, Illinois, Kentucky, Nebraska, Pennsylvania, and West Virginia. Note cards include a brief description, informant’s name, and the motif index number

Does the stock market react to unsolicited ratings?

This paper investigates whether the stock market reacts to unsolicited ratings for a sample of S&P rated firms from January 1996 to December 2005. We first analyze the stock market reaction associated with the assignment of an initial unsolicited rating. We find evidence that this reaction is negative and particularly accentuated for Japanese firms. A comparison between S&P’s initial unsolicited ratings with previously published ratings of two Japanese rating agencies for a Japanese subsample shows that ratings assigned by S&P are systematically worse. Further, we find that the stock market does not react to the transition from an unsolicited to a solicited rating. Comparison of the upgrades in the sample with a matched-sample of upgrades of solicited ratings reveals that the price reactions are no different. In addition, abnormal returns are worse for firms whose rating remained unchanged after the solicitation compared to those for upgraded firms. Finally, we find that Japanese firms are less likely to receive an upgrade. Our findings suggest that unsolicited ratings are biased downwards, that the capital market therefore expects upgrades of formerly unsolicited ratings and punishes firms whose ratings remain unchanged. All these effects seem to be more pronounced for Japanese firms