A comparison between large-scale irregularities and scintillations in the polar ionosphere

A comparison tool has been developed by mapping the global GPS total electron content (TEC) and large coverage of ionospheric scintillations together on the geomagnetic latitude/magnetic local time coordinates. Using this tool, a comparison between large-scale ionospheric irregularities and scintillations are pursued during a geomagnetic storm. Irregularities, such as storm enhanced density (SED), middle-latitude trough and polar cap patches, are clearly identified from the TEC maps. At the edges of these irregularities, clear scintillations appeared but their behaviors were different. Phase scintillations (σsub{φ}) were almost always larger than amplitude scintillations (S4) at the edges of these irregularities, associated with bursty flows or flow reversals with large density gradients. An unexpected scintillation feature appeared inside the modeled auroral oval where S4 were much larger than σsub{φ}, most likely caused by particle precipitations around the exiting polar cap patches.

Development and calibration of a portable radon sampling system for groundwater (222)Rn activity concentration measurements

The assembling of a system for field sampling and activity concentration measurement of radon dissolved in groundwater is described. Special attention is given in presenting the calibration procedure to obtain the radon activity concentration in groundwater from the raw counting rate registered in a portable scintillation detector and in establishing the precision of the activity concentration measurements. A field procedure was established and the system tested during one year of monthly observations of (222)Rn activity concentration in groundwater drawn from two wells drilled on metamorphic rocks exposed at Eastern Sao Paulo State, Brazil. The observed mean (222)Rn activity concentrations are 374 Bq/dm(3) in one well and about 1275 Bq/dm(3) in the other one. In both wells the (222)Rn activity concentrations showed a seasonal variation similar to variations previously reported in the literature for the same region. (C) 2009 Elsevier Ltd. All rights reserved.

S100 beta Protein Expression: Gender- and Age-Related Daily Changes

S100 beta is a soluble protein released by glial cells mainly under the activation of the 5-HT1A receptor. It has been reported as a neuro-trophic and -tropic factor that promotes neurite maturation and outgrowth during development. This protein also plays a role in axonal stability and the plasticity underlying long-term potentiation in adult brains. The ability of S100 beta to rapidly regulate neuronal morphology raises the interesting point of whether there are daily rhythm or gender differences in S100 beta level in the brain. To answer this question, the S100 beta expression in adult female and male rats, as well as in adult female CD-21 and S100 beta -/- female mice, were investigated. Scintillation counting and morphometric analysis of the immunoreactivity of S100 beta, showed rhythmic daily expression. The female and male rats showed opposite cycles. Females presented the highest value at the beginning of the rest phase (5:00 h), while in males the maximum value appeared in the beginning of the motor activity period (21:00 h). These results confirm previous S100 beta evaluations in human serum and cerebrospinal fluid reporting the protein`s function as a biomarker for brain damage (Gazzolo et al. in Clin Chem 49:967-970, 2003; Clin Chim Acta 330:131-133, 2003; Pediatr Res 58:1170-1174, 2005), similar behavior was also observed for GFAP in relation to Alzheimer Disease (Fukuyama et al. in Eur Neurol 46:35-38, 2001). The data should be taken into account when considering S100 beta as a biomarker of health condition. In addition, the results raise questions on which structure or condition imposes these rhythms as well as on the physiological meaning of the observed gender differences.

A dedicated setup for the measurement of the electron transport parameters in gases at large electric fields

Electron transport parameters are important in several areas ranging from particle detectors to plasma-assisted processing reactors. Nevertheless, especially at high fields strengths and for complex gases, relatively few data are published. A dedicated setup has been developed to measure the electron drift velocity and the first Townsend coefficient in parallel plate geometry. An RPC-like cell has been adopted to reach high field strengths without the risk of destructive sparks. The validation data obtained with pure Nitrogen will be presented and compared to a selection of the available literature and to calculations performed with Magboltz 2 version 8.6. The new data collected in pure Isobutane will then be discussed. This is the first time the electron drift velocity in pure Isobutane is measured well into the saturation region. Good agreement is found with expectations from Magboltz. (C) 2009 Elsevier B.V. All rights reserved.

Omläggning av skiftgång

The digital printing market is changing faster now than before and the ability to adjust to newsituations has become more importat to a printing company. An efficient internal communicationis essential. At Elanders Digitaltryck a decision was made in august 2002 to look over the shiftworking system for the printer operators. In this paper, an investigation of the possibilities tochange the existing system to a better one was made.The project resultet in four different timetabels. The construction was based on theoretical studiesand an analysis of the current situation at the workplace. The analysis showed that a strong resistanseagainst a change of the working hours exists among the workers and that this should beconsidered before a decision is made. An analasys of the printers counters shows that they areused more efficient during shorter shift periods compared to the longer ones. A closeer look at theabcense due to sickness shows that it is relatively high but no connection between abcense andworking hours could be made.Working hours is a sensitive issue and should be treated with care. It is important that the workersare well informed and preferly involved in the development of a new timetable.

10 Reasons Why the Internet Is No Substitute for a Library

In an effort to save our culture, strike a blow for reading, and, above all, correct the well-intentioned but horribly misguided notions about what is fast becoming Intertopia among many nonlibrarian bean counters, here are 10 reasons why the Internet is no substitute for a library.

Designing single event upset mitigation techniques for large SRAM-Based FPGA components

This thesis presents the study and development of fault-tolerant techniques for programmable architectures, the well-known Field Programmable Gate Arrays (FPGAs), customizable by SRAM. FPGAs are becoming more valuable for space applications because of the high density, high performance, reduced development cost and re-programmability. In particular, SRAM-based FPGAs are very valuable for remote missions because of the possibility of being reprogrammed by the user as many times as necessary in a very short period. SRAM-based FPGA and micro-controllers represent a wide range of components in space applications, and as a result will be the focus of this work, more specifically the Virtex® family from Xilinx and the architecture of the 8051 micro-controller from Intel. The Triple Modular Redundancy (TMR) with voters is a common high-level technique to protect ASICs against single event upset (SEU) and it can also be applied to FPGAs. The TMR technique was first tested in the Virtex® FPGA architecture by using a small design based on counters. Faults were injected in all sensitive parts of the FPGA and a detailed analysis of the effect of a fault in a TMR design synthesized in the Virtex® platform was performed. Results from fault injection and from a radiation ground test facility showed the efficiency of the TMR for the related case study circuit. Although TMR has showed a high reliability, this technique presents some limitations, such as area overhead, three times more input and output pins and, consequently, a significant increase in power dissipation. Aiming to reduce TMR costs and improve reliability, an innovative high-level technique for designing fault-tolerant systems in SRAM-based FPGAs was developed, without modification in the FPGA architecture. This technique combines time and hardware redundancy to reduce overhead and to ensure reliability. It is based on duplication with comparison and concurrent error detection. The new technique proposed in this work was specifically developed for FPGAs to cope with transient faults in the user combinational and sequential logic, while also reducing pin count, area and power dissipation. The methodology was validated by fault injection experiments in an emulation board. The thesis presents comparison results in fault coverage, area and performance between the discussed techniques.

Oficiais da Marinha Mercante: um estudo sobre os fatores contribuintes para a evasão nos anos iniciais da carreira embarcada

A indústria de transporte marítimo brasileira passa por um momento de forte expansão decorrente, entre outros fatores, de políticas governamentais que incentivam a construção, nos estaleiros nacionais, de navios para serem utilizados em apoio às atividades da indústria de óleo e gás. Ao mesmo tempo, para complementar a frota brasileira, as empresas petroleiras demandam a contratação de grande quantidade de navios estrangeiros para apoiar as suas operações. Este quadro de crescimento da frota, observado, particularmente, nos últimos 10 anos, contrasta com a escassez de mão de obra qualificada para tripular as embarcações, de modo especial dos Oficiais da Marinha Mercante (OMM). Acentuando o contraste, o Conselho Nacional de Imigração editou a Resolução Normativa n° 72/2006, determinando às empresas de navegação, que operam barcos de bandeira estrangeira, a contratação de proporções mínimas de tripulantes brasileiros, após 90 dias contínuos de operação no país. Além disso, estudos encomendados pelo Sindicato dos Armadores, SYNDARMA, apontam que a taxa de evasão dos OMM, nos anos iniciais da carreira embarcada, é de cerca de trinta por cento. Assim, o presente estudo, a partir de uma revisão bibliográfica acerca da história da Marinha Mercante brasileira, da cultura brasileira, da motivação, dos conflitos família-trabalho, do trabalho em espaço confinado e da rotatividade, se desenvolveu em uma pesquisa exploratória e de campo, por meio de entrevistas pessoais, analisadas à luz da técnica da análise de conteúdo, com profissionais de reconhecida experiência com o tema, além de OMM, com o objetivo de identificar os fatores contribuintes para a evasão dos OMM nos anos iniciais da carreira embarcada. Como resultado, o estudo mostrou que os agentes motivadores intrínsecos e extrínsecos agem continuamente direcionando o comportamento dos OMM para a permanência ou saída da carreira embarcada. Nessa alternância de forças psicológicas e comportamentais, associadas à motivação, influenciam no processo decisório as alternativas existentes representadas pelas oportunidades de emprego oferecidas aos OMM, os conflitos trabalho-família e a dificuldade de adaptação ao trabalho em ambiente confinado. No caso dos OMM, do gênero feminino, a situação é ainda mais sensível, pois enfrentam dificuldades para conciliar a vida embarcada com o papel de mãe e esposa. Portanto, a motivação para a permanência ou saída da carreira embarcada está fortemente relacionada à busca pela realização das expectativas pessoais e ao desejo de equilibrar vida pessoal com a profissional.

Meta-theories in research: positivism, postmodernism, and critical realism

No scholar or researcher is able to provide robust evidence that counters the scant reflection on metatheory – mostly ontology and epistemology – underlying management studies in general, and industrial marketing and purchasing research in particular. This paper is a contribution to the indispensable discussion of metatheoretical alternatives in research, and most importantly, the strengths and shortcomings thereof, and respective implications on research questions, objectives, and findings.

Quality of TEC Estimated with Mod Ion Using GPS and GLONASS Data

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos de tempestades magnéticas em sinais de gps, em Natal, Brasil

Satellites signals present disturbances (scintillations), due to presence of irregularities in the ionospheric plasma. In the present work, we dedicate to the study of the attenuation of these scintillations that is, an improvement in the signal, during the main magnetic storm phase during the period of October 2006 to February 2007. Using amplitude of scintillation 1.5GHz (L1) data of the net of satellites GPS, in the ionospheric station of Natal (5.84o S, 35.20o O, -20o dip) and geomagnetic indices, during the minimum solar cycle (referred to as cycle 23), demonstrating its anti-correlation between magnetic activity (Kp) and index of scintillation () (Bonelli2005 method, that works for solar maximum, Bonelli(2005)). These results show that these storms correspond to category I of Aarons (1991). The magnetic storms can generate irregularities when the electric feld of penetration eastward on the pre-reversal hour intensificating that and can too generate irregularities on midnight and sunlight period. The limitation of the method applied here is that it is not considering some storms that had also occurred during equinox and summer in the Brazilian region. For this reason, we will use additional data of the stations of São João de Cariri (Imager and Photometer) and of the station at Fortaleza (Digissonde data), as aid to analyze these storms. The storms that had been left out by the applied method, fit in the other two categories of Aarons, with one only exception (storm of January, 02). We show that in the day of the main phase of the magnetic storm, and with presence of bubbles (according to data of the Imager and Photometer), the speed of vertical drift ~E ~B (hF=t) is below 20m/s, that is the threshold found for Anderson al., (2004) (>20m/s as condition favorable to the formation of irregularities and increase in the scintillation index). This reduction of the speed is due to solar minimum

In vivo determination of incorporated activity of Tc-99(m)-MDP in bone tissue

In vivo determination of the incorporated activity of Tc-99(m)-MDP (methylene diphosphonate) in bone tissue by means of a scintillation camera requires calibration of the device. This can be carried out by using an anthropomorphic physical phantom. In this work, a new human tibia and fibula phantom is presented to estimate incorporated activity to bone tissue. A tibia and a fibula, taken from a real skeleton, were used to develop the phantom. Images were acquired of the legs of 65 volunteers at different times of incorporation (minimum of 120 and maximum of 2500 min after injection) and count rates of such a region were obtained by means of a computer program. The calibration factor obtained was then used to assess the activity in the two bents. The final result is 0.4995 kBq per cpm for technetium. The proposed method can be used both for radiation protection purposes and for metabolism studies.

Ventilatory compensation of the alkaline tide during digestion in the snake Boa constrictor

The increased metabolic rate during digestion is associated with changes in arterial acid-base parameters that are caused by gastric acid secretion (the 'alkaline tide'). Net transfer of HCl to the stomach lumen causes an increase in plasma HCO3- levels, but arterial pH does not change because of a ventilatory compensation that counters the metabolic alkalosis. It seems, therefore, that ventilation is controlled to preserve pH and not P-CO2, during the postprandial period. To investigate this possibility, we determined arterial acid-base parameters and the metabolic response to digestion in the snake Boa constrictor, where gastric acid secretion was inhibited pharmacologically by oral administration of omeprazole. The increase in oxygen consumption of omeprazole-treated snakes after ingestion of 30% of their own body mass was quantitatively similar to the response in untreated snakes, although the peak of the metabolic response occurred later (36 h versus 24 h). Untreated control animals exhibited a large increase in arterial plasma HCO3- concentration of approximately 12 mmol 1(-1), but arterial pH only increased by 0.12 pH units because of a simultaneous increase in arterial P-CO2 by about 10 mmHg. Omeprazole virtually abolished the changes in arterial pH and plasma HCO3- concentration during digestion and there was no increase in arterial P-CO2. The increased arterial P-CO2 during digestion is not caused, therefore, by the increased metabolism during digestion or a lower ventilatory responsiveness to ventilatory stimuli during a presumably relaxed state in digestion. Furthermore, the constant arterial P-CO2, in the absence of an alkaline tide, of omeprazole-treated snakes strongly suggests that pH rather than P-CO2 normally affects chemoreceptor activity and ventilatory drive.

The CMS experiment at the CERN LHC

The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10(34)cm(-2)s(-1) (10(27)cm(-2)s(-1)). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4 pi solid angle. Forward sampling calorimeters extend the pseudo-rapidity coverage to high values (vertical bar eta vertical bar <= 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t.

Contadores eletrônicos no laboratório didático: parte II. Medida de intervalos de tempo sucessivos

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