Commissioning and performance of the CMS silicon strip tracker with cosmic ray muons

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

b-Jet identification in the D0 experiment

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A novel method for modeling the recoil in W boson events at hadron colliders

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of detector motion in Bell inequalities with entangled fermions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of detector motion in entanglement measurements with photons

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Search for heavy stable charged particles in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determination of jet energy calibration and transverse momentum resolution in CMS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Performance of tau-lepton reconstruction and identification in CMS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The natural radioactivity in water by gross alpha and beta measurements

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cromatografia gasosa ultrarrápida: uma visão geral sobre parâmetros, instrumentação e aplicações

Since the introduction of GC there has been an ongoing interest in reducing time of analysis resulting in new terms and definitions such as ultra fast gas chromatography (UF-GC). One of the most used definitions describes UF-GC as a technique that combines the employment of short narrow bore column with very fast temperature programming rates producing chromatographic peaks in the range of 50 ms and allowing separations times in 1-2 min or less. This paper summarizes the analytical approaches, the main parameters involved and the instrumentation towards UF-GC.

Bats from Fazenda Intervales, Southeastern Brazil: species account and comparison between different sampling methods

Assessing the composition of an area's bat fauna is typically accomplished by using captures or by monitoring echolocation calls with bat detectors. The two methods may not provide the same data regarding species composition. Mist nets and harp traps may be biased towards sampling low flying species, and bat detectors biased towards detecting high intensity echolocators. A comparison of the bat fauna of Fazenda Intervales, southeastern Brazil, as revealed by mist nets and harp trap captures, checking roosts and by monitoring echolocation calls of flying bats illustrates this point. A total of 17 species of bats was sampled. Fourteen bat species were captured and the echolocation calls of 12 species were recorded, three of them not revealed by mist nets or harp traps. The different sampling methods provided different pictures of the bat fauna. Phyllostomid bats dominated the catches in mist nets, but in the field their echolocation calls were never detected. No single sampling approach provided a complete assessment of the bat fauna in the study area. In general, bats producing low intensity echolocation calls, such as phyllostomids, are more easily assessed by netting, and bats producing high intensity echolocation calls are better surveyed by bat detectors. The results demonstrate that a combined and varied approach to sampling is required for a complete assessment of the bat fauna of an area.

Determination of the U-238 spontaneous fission decay constant without neutron irradiation

We have developed a methodology for measuring the decay constant of the spontaneous fission of U-238, lambda(f), using nuclear particle track detectors where thermal neutron irradiation is unnecessary. This methodology is based on the fact that the radiation damage caused by spontaneous fission of trans-uranium elements bearing a mass number close to 238 are similar to U-238 spontaneous-fission ones. Loading a thick source of uranium (thickness greater than the fission fragment range) with a small amount of a suitable trans-uranium element (for instance, Pu-242, which presents a spontaneous fission half-life of 6.75(.)10(10) y), it is possible to determine the observation efficiency of a particle-track detector for fission fragments. Procedures concerning our thick source manufacture and uniformity tests of the trans-uranium distribution are also presented. These results make it possible for the exposure of thick uranium sources (without trans-uranium element) to lead to a lambda(f) value.

Ferroelectric ceramic/polymer composite for measuring X-ray intensity in the ortovoltage range

Pyroelectric sensors work as a thermal transducer converting the non-quantified thermal flux into the output measurable quantity of electrical charge, voltage or current. Ferroelectric ceramics and ferroelectric polymers have been extensively used as thermal detectors. More recently the research in the field of pyroelectricity has been concentrated on discovering materials with higher figures of merit (FOM), which means better sensing materials. Composite materials obtained with ferroelectric ceramics embedded in polymer host have received great attention because of their formability, mechanical resistance and the possibility to change their dielectric property varying the volume fraction of ceramic particles. In this work composite films made of modified lead titanate (PZ34) and poly(ether-ether-ketone) (PEEK) were characterized and used as sensing element to measure X-ray intensity in the ortovoltage range (120 - 300 kVp). The sensor response varies from 2.70 V to 0.80 V in the energy fluency range of 6.30 to 37.20 W/m(2). Furthermore the absorbed energy was analyzed as a function of the ionizing energy. The results indicate that the PZ34/PEEK composite with 60/40 vol.% can be useful to monitor X-ray radiation therapy.

BACKGROUND THERMAL CONTRIBUTIONS IN TESTING THE UNRUH EFFECT

We consider inertial and accelerated Unruh-DeWitt detectors moving in a background thermal bath and calculate their excitation rate. It is shown that for fast moving detectors such a thermal bath does not affect substantially the excitation probability. Our results are discussed in connection with a possible proposal of testing the Unruh effect in high energy particle accelerators.

GC analysis of organotin compounds using pulsed flame photometric detection and conventional flame photometric detection

Organotin compounds, largely used as biocides in antifouling paints, are among the most toxic materials introduced into the aquatic environment. Sensitive analytical methods are thus required to characterize their occurrence in environmental and biological matrices. The comparison between two different photometric detectors in terms of analytical performance was carried out for the analysis of organotin compounds. A flame photometric detector (FPD) and a pulsed flame photometric detector (PFPD) were optimized. Their respective sensitivity, linearity range and selectivity were evaluated. Limits of detection obtained for a tributyltin compound (TBT) were 5.0 and 0.9 pg (as Sn) for the FPD and PFPD, respectively, using a 390 nm filter. The PFPD showed higher selectivity, besides reduced gas consumption in the flame, and is very attractive for organotin compound speciation in complex environmental matrices.