CMS-HF Calorimeter Upgrade for Run II

CMS-HF Calorimeters have been undergoing a major upgrade for the last couple of years to alleviate the problems encountered during Run I, especially in the PMT and the readout systems. In this poster, the problems caused by the old PMTs installed in the detectors and their solutions will be explained. Initially, regular PMTs with thicker windows, causing large Cherenkov radiation, were used. Instead of the light coming through the fibers from the detector, stray muons passing through the PMT itself produce Cherenkov radiation in the PMT window, resulting in erroneously large signals. Usually, large signals are the result of very high-energy particles in the calorimeter and are tagged as important. As a result, these so-called window events generate false triggers. Four-anode PMTs with thinner windows were selected to reduce these window events. Additional channels also help eliminate such remaining events through algorithms comparing the output of different PMT channels. During the EYETS 16/17 period in the LHC operations, the final components of the modifications to the readout system, namely the two-channel front-end electronics cards, are installed. Complete upgrade of the HF Calorimeter, including the preparations for the Run II will be discussed in this poster, with possible effects on the eventual data taking.Comment: Presented at The Fifth Annual Conference on Large Hadron Collider Physics Shanghai Jiao Tong University, Shanghai, China May 15-20, 201

A chiral covariant approach to ρρ\rho\rho scattering

We analyze vector meson - vector meson scattering in a unitarized chiral theory based on a chiral covariant framework. We show that a pole assigned to the the scalar meson $f_0(1370)$ can be dynamically generated from the $\rho\rho$ interaction, while this is not the case for the tensor meson $f_2(1270)$ as found in earlier works. We show that the generation of the tensor state is untenable due to an artefact of the extreme non-relativistic kinematics used before. We further consider the effects arising from the coupling of channels with different orbital angular momenta. We suggest to use the formalism outlined here to obtain more reliable results for the dynamical generation of resonances in the vector-vector interaction.Comment: 31 pages, 10 figures, extended version, new section with an improved solution method, results and conclusions unchange

The CMS-HF Forward Calorimeter Commissioning

The CMS HF Calorimeter was the first detector to be lowered into the cavern at UX5. It was placed in the garage position during the lowering of the rest of the big CMS pieces. The commissioning of the hardware parts is continuing. Especially, integrating the HF and completing the monitoring systems, such as, online laser, LED and radioactive source monitoring. Also a special monitor system for the radiation damage (raddam) of the quartz fibers is being implemented. Calibration measurements of the calorimeter had started already even before the lowering. Progress in the calibration work and current plans for the HF calorimeter during the low luminosity run will be summarized

Sıvı yakıtlı roket motorlarında püskürtücü atomizasyonunun deneysel ve sayısal araştırması

Since the liquid rocket engines have been widely used in various flight applications, improving the efficiency and stability of those engines have become important. To achieve efficient combustion in the chamber, the injector must be carefully designed and characterized well. Although impinging jet injectors are widely used in several systems, the previous researches focused on mainly the characterization of like-doublets, thus, there is still a lack of understanding on the atomization of the other types of impinging injectors. In this study, triplet and pentad type of impinging injectors are examined both experimentally and numerically. Parameters that affect the spray distribution, velocity and droplet statistics are analyzed and a group of injectors for both injector elements are tested with a mechanical patternator, a PDA, and a high-speed camera. It is seen that while some parameters enhance the results obtained by triplet injectors, they either deteriorate the results obtained by pentad injectors or do not have an obvious effect. For numerical results, a CLSVOF technique with the AMR method is used to simulate the spray characteristics of doublet, triplet and pentad injectors. Results indicate that this numerical method can be used to analyze the performance of these injectors with a reasonable accuracy compared to experimental data.Sıvı yakıtlı roket motorları çeşitli uçuş görevlerinde sıklıkla kullanıldığı için, bu motorların verimini ve kararlığını artırmak önemli hale gelmiştir. Yanma odasında verimli bir yanmanın sağlanması için püskürtücünün dikkatle tasarlanması ve iyi karakterize edilmesi gerekmektedir. Çarpışan jet tipi püskürtücüler çeşitli sistemlerde kullanılmasına rağmen, önceki çalışmalar çoğunlukla eşlenik dubletlerin karakterizasyonuna odaklanmıştır; bu yüzden diğer tip çarpışan püskürtücülerin atomizasyonunun anlaşılması için yeterli bilgi halen bulunmamaktadır. Bu çalışmada, çarpışan püskürtücü olan triplet ve pentad tipi püskürtücüler deneysel ve sayısal yöntemlerle incelenmiştir. Sprey dağılımı, hız ve damlacık istatistiklerini etkileyen değişkenler incelenmiş ve iki tip püskürtücüden oluşan püskürtücü grubu mekanik paternatör, PDA ve hızlı kamera ile test edilmiştir. Bazı değişkenlerin triplet püskürtücülerden elde edilen sonuçları iyileştirirken, pentad püskürtücülerden elde edilen sonuçları ya kötüleştirdiği ya da pek etkilemediği görülmüştür. Nümerik sonuçlar için, AMR metodu eşliğinde CLSVOF tekniği kullanılarak dublet, triplet ve pentad püskürtücülerin sprey karakteristiklerinin benzetimi yapılmıştır. Sonuçlar, bu sayısal yöntemin deneysel veriye göre kabul edilebilir bir doğruluk seviyesinde sonuç verecek şekilde bu tip püskürtücülerin performansının incelenmesinde kullanılabileceğini göstermektedir.M.S. - Master of Scienc

Stenotrophomonas maltophilia: antimicrobial resistance and molecular typing of an emerging pathogen in a Turkish university hospital

ABSTRACTDespite its limited pathogenicity, Stenotrophomonas maltophilia is an emerging nosocomial pathogen. This study investigated the isolation frequency, antimicrobial resistance and genotypic relationships of 205 S. maltophilia isolates from 188 patients in a university hospital between 1998 and 2003. Susceptibility profiles for 11 antimicrobial agents were determined by the NCCLS agar dilution method for non-fermentative bacteria, while enterobacterial repetitive intergenic consensus sequence (ERIC)-PCR and pulsed-field gel electrophoresis (PFGE) were used for genotyping of the isolates. Of the 205 isolates, 56.1% were isolated in the last 2 years of the study. The risk of S. maltophilia isolation was higher in intensive care units, S. maltophilia was isolated mostly (86.8%) after hospitalisation for ≥48 h, and 90.4% of the patients had underlying diseases. Resistance levels were >60% for all antimicrobial agents tested except co-trimoxazole. High genetic diversity was found among the S. maltophilia isolates, and cross-infection with S. maltophilia was not common. Although ERIC-PCR revealed fewer genotypes than PFGE, it proved to be a rapid and easy method for S. maltophilia genotyping, and was more economical than PFGE

Vector-meson interactions, dynamically generated molecules, and the hadron spectrum

We study the lowest-lying vector-meson interactions and dynamically generated bound states. Therefore, these bound states are studied as hadronic molecules. We demonstrate that some unitarization methods are not well-defined to study the pole structures of amplitudes in the region far from the threshold. We employ an improved unitarization method based on a covariant formalization that is necessary to study the pole structures of amplitudes in the region far from the threshold. In this work, first, we study the analysis of the covariant ρρ scattering in a unitarized chiral theory and then extend it to the strange sector, i.e. SU(3) chiral symmetry. We demonstrate that the on-shell factorization of the Bethe-Salpeter equation is not suitable away from the threshold. Moreover, the left-hand cuts would overlap the right-hand cuts for the coupled-channel unitarization of the Bethe-Salpeter equation. It makes unitarized amplitudes non-analytical and the poles of amplitudes, associated to possible bound states or resonances, unreliable. To avoid this difficulty, we employ the first iterated solution of the N/D method and investigate the possible dynamically generated resonances and bound states. A comparison with the non-relativistic calculation is provided as well

Preparing Perform and Impact Ready Instructional Leaders for Improving Urban School Success

In an effort to develop and support high quality urban school leaders, this study examined what factors affect pre-service urban school leaders' perception of preparedness for performing instructional leadership activities. The findings revealed that participating in a leadership training program is the only significant factor that predicts urban educators' scores on instructional leadership readiness measures. By examining perception of preparedness of aspiring urban school leaders the findings contribute to our understanding about some perspectives to prepare and develop urban school leaders solve large and complex problems related to the curriculum, instruction and assessment. Implications for preparing performance ready school leaders in high need urban schools are further discussed