ANNEALING OF POLYCRYSTALLINE THIN FILM SILICON SOLAR CELLS IN WATER VAPOUR AT SUB-ATMOSPHERIC PRESSURES

Thin film polycrystalline silicon (poly-Si) solar cells were annealed in water vapour at pressures below atmospheric pressure. PN junction of the sample was contacted by measuring probes directly in the pressure chamber filled with steam during passivation. Suns-VOC method and a Lock-in detector were used to monitor an effect of water vapour to VOC of the solar cell during whole passivation process (in-situ). Tested temperature of the sample (55°C – 110°C) was constant during the procedure. Open-circuit voltage of a solar cell at these temperatures is lower than at room temperature. Nevertheless, voltage response of the solar cell to the light flash used during Suns-VOC measurements was good observable. Temperature dependences for multicrystalline wafer-based and polycrystalline thin film solar cells were measured and compared. While no significant improvement of thin film poly-Si solar cell parameters by annealing in water vapour at under-atmospheric pressures was observed up to now, in-situ observation proved required sensitivity to changing VOC at elevated temperatures during the process

Hydraulic assesment of river and design of flood protection

Bakalářská práce se zabývá hydraulickým posouzením kapacity koryta při povodňových průtocích na řece Leskavě v ř. km 1,600 po ř. km 3,843. Analýza byla prováděna v programu HEC-RAS 5.0 s využitím kombinace proudění povrchové vody, které bylo simulované pomocí 1D a 2D numerického modelu. Výpočet probíhal pro průtoky Q5, Q20, Q100. Bakalářská práce navazuje a čerpá ze studie ke Generelu odvodnění města Brna. Byly porovnány výsledky výpočtů ze stávajících podkladů přejatých z Generelu odvodnění města Brna s nově vzniklými výsledky ve formě bakalářské práce. Závěrem, na základě výsledných hloubek vody a velikosti rozlivů, bylo provedeno zhodnocení výsledků a navrženo ideové protipovodňové opatření.The bachelor thesis deals with the hydraulic analysis of the water flow of flood flow on the river Leskava from river station km 1,600 to river station 3,843 km. Hydraulic analysis was performed in the program HEC-RAS 5.0. using a combination of the flow of surfacewater in the 1D and 2D model. The calculation was carried out for the flow rates Q5, Q20, Q100. Bachelor thesis builds on the study to the General plan of the drainage of the city of Brno. In conclusion, on the basis of the resulting depths of the water and the size of the flood areas it was proposed to appropriate flood control measures in the form of idea flood protection.

Design of the reinforced concrete monolithic structure of the multifunctional building with a basement

Bakalářská práce se zaměřuje na návrh a posouzení vybraných částí železobetonové konstrukce polyfunkčního domu s lokálně podepřenými deskami, průvlakem, návrhem a posudkem sloupů, suterénní stěny a schodiště. V práci jsou postupně po kapitolách rozpracovány jednotlivé dílčí kroky vedoucí k hospodárným návrhům a následně posudkům vybraných částí konstrukcí a to dle platných norem.The bachelor thesis focuses on the design and assessment of selected components of a reinforced concrete structure of mixed-use building with locally supported slabs, a beam, design and assessment of columns, basement walls, and staircase. The thesis progressively elaborates on individual steps in chapters leading to economical designs and subsequent assessments of selected structural elements according to applicable standards.221 - Katedra konstrukcívelmi dobř

Search for the QCD critical point in nuclear collisions at the CERN SPS

Pion production in nuclear collisions at the SPS is investigated with the aim to search, in a restricted domain of the phase diagram, for power-laws in the behavior of correlations which are compatible with critical QCD. We have analyzed interactions of nuclei of different size (p+p, C+C, Si+Si, Pb+Pb) at 158$A$ GeV adopting, as appropriate observables, scaled factorial moments in a search for intermittent fluctuations in transverse dimensions. The analysis is performed for $\pi^+\pi^-$ pairs with invariant mass very close to the two-pion threshold. In this sector one may capture critical fluctuations of the sigma component in a hadronic medium, even if the $\sigma$-meson has no well defined vacuum state. It turns out that for the Pb+Pb system the proposed analysis technique cannot be applied without entering the invariant mass region with strong Coulomb correlations. As a result the treatment becomes inconclusive in this case. Our results for the other systems indicate the presence of power-law fluctuations in the freeze-out state of Si+Si approaching in size the prediction of critical QCD.Comment: 31 pages, 11 figure

High p_T Spectra of Identified Particles Produced in Pb+Pb Collisions at 158GeV/nucleon Beam Energy

Transverse momentum spectra of pi^{+/-}, p, pbar, K^{+/-}, K^0_s and Lambda at midrapidity were measured at high p_T in Pb+Pb collisions at 158GeV/nucleon beam energy by the NA49 experiment. Particle yield ratios (p/pi, K/pi and Lambda/K^0_s) show an enhancement of the baryon/meson ratio for p_T>2GeV/c. The nuclear modification factor R_{CP} is extracted and compared to RHIC measurements and pQCD calculations.Comment: Quark Matter 2005 parallel section proceeding

Upper Limit of D0 Production in Central Pb-Pb Collisions at 158A GeV

Results are presented from a search for the decays D0 -> Kmin piplus and D0bar -> Kplus pimin in a sample of 3.8x10^6 central Pb-Pb events collected with a beam energy of 158A GeV by NA49 at the CERN SPS. No signal is observed. An upper limit on D0 production is derived and compared to predictions from several models.Comment: REVTEX 5 pages, 4 figure