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排序方式: 共有434条查询结果,搜索用时 15 毫秒
1.
Integrated tests (IT) applied to the Units I and II of the CNAAA Nuclear Power Plants (Angra dos Reis, Rio de Janeiro, Brazil) vara part of a comprehensive test program required to have the commercial operational licence issued. The IT cover operation at zero power and the subsequent power levels (the power escalation) until the nominal power operation.
This paper reports and compares the results of systematic neutron and gamma equivalent dose-rate measurements performed inside and outside the reactor containment of each Unit, during the start-up phase of the operation, for different power levels of the reactors. It also compares the collective-doses measured along the operation of the two units of the CNAAA wich similar data of the Grafenrheinfeld nuclear power plant (Germany) — basic-of-project for the CNAAA — Unit II — and analyses the data under the fight of the state-of-art. 相似文献
2.
E. M. Telles J. C. S. Moraes A. Scalabrin D. Pereira G. Carelli C. A. Massa A. Moretti F. Strumia 《Journal of Infrared, Millimeter and Terahertz Waves》1995,16(12):2233-2248
We used a Stark-Optoacoustic cell and hybrid waveguide resonators to perform an Infrared and Far Infrared Stark Spectroscopy study on some transitions of13CD3OH. Different behaviours of the transitions in the presence of a d.c. electric field were observed. The Stark splittings of six FIR laser lines ranging from 34 to 136 MHz/kVcm?1 were determined. The analysis of the behaviour of the IR and FIR transitions in the presence of the external electric fields gives important and exclusive information on the levels involved in the transitions. 相似文献
3.
The IBF has for some years made use of finite element programmes to solve metal-forming problems. In the course of this investigation, it has become evident that a problem-oriented adaptation of FEM simulation to the problem in hand is beneficial in terms of computation effort. The computation time for the process parameters is optimised in a multi-level simulation. At level 1 (global analysis) integral parameters such as the required force and required work are computed using a coarse FEM mesh. At level 2 (local analysis) an optimised number of elements is used to determine continuum mechanics parameters like stress, strain and temperature. Microscopic phenomena are simulated at level 3 (microscopic analysis), using special micro-material elements and thermodynamic models. 相似文献
4.
G. Carelli N. Ioli J. C. S. Moraes A. Moretti F. Strumia G. E. Annino A. Bertolini 《Journal of Infrared, Millimeter and Terahertz Waves》1996,17(6):1023-1030
The results described in this work are part of a systematic search for long wavelength laser lines to be used in high magnetic field EPR applications and in plasma diagnostic. Four new far-infrared laser lines of CH2 = CF2 (1,1 difluoroethylene), optically pumped by a waveguide CO2 laser, have been discovered and characterized in wavelength, polarization relative to the pumping radiation and offset relative to the CO2 center frequency. New measurements of polarization and offset of 5 already known laser lines are also reported. A table of all of the known CO2 pumped FIR laser lines from this molecule is given. 相似文献
5.
Andrielli Morais de Oliveira Flávio de Andrade Silva Eduardo de Moraes Rego Fairbairn Romildo Dias Toledo Filho 《Materials and Structures》2018,51(3):65
This paper reports the experimental findings on the tensile behavior of strain-hardening cement-based composites (SHCC). The composites were subjected to the combined effects of elevated temperatures and internal moisture condition. Uniaxial tensile tests on dumbbell-shaped SHCC specimens with in situ temperature control were performed at 22, 60 and 100 °C. In addition, the effect of the internal humidity of SHCC (95, 50, 20 and 0%) coupled to the elevated temperatures was investigated. It was shown that the tensile strength decreases and the strain capacity increases with an increase in temperature. The influence of the internal moisture conditions was more significant in high temperatures. The strain capacity reduced significantly with a decrease in the humidity level. The crack pattern of the SHCC specimens was determined. Furthermore, single fiber pullout tests were performed under the considered high temperatures condition. Finally, the results are discussed based on the thermogravimetry analysis of the PVA fiber, alterations on its microstructure and surface coating. 相似文献
6.
Carolina Gismene Jorge Enrique Hernndez Gonzlez Angela Rocio Nio Santisteban Andrey Fabricio Ziem Nascimento Lucas dos Santos Cunha Fbio Rogrio de Moraes Cristiano Luis Pinto de Oliveira Caio C. Oliveira Paola Jocelan Scarin Provazzi Pedro Geraldo Pascutti Raghuvir Krishnaswamy Arni Ricardo Barros Mariutti 《International journal of molecular sciences》2022,23(17)
Staphylococcal exfoliative toxins (ETs) are glutamyl endopeptidases that specifically cleave the Glu381-Gly382 bond in the ectodomains of desmoglein 1 (Dsg1) via complex action mechanisms. To date, four ETs have been identified in different Staphylococcus aureus strains and ETE is the most recently characterized. The unusual properties of ETs have been attributed to a unique structural feature, i.e., the 180° flip of the carbonyl oxygen (O) of the nonconserved residue 192/186 (ETA/ETE numbering), not conducive to the oxyanion hole formation. We report the crystal structure of ETE determined at 1.61 Å resolution, in which P186(O) adopts two conformations displaying a 180° rotation. This finding, together with free energy calculations, supports the existence of a dynamic transition between the conformations under the tested conditions. Moreover, enzymatic assays showed no significant differences in the esterolytic efficiency of ETE and ETE/P186G, a mutant predicted to possess a functional oxyanion hole, thus downplaying the influence of the flip on the activity. Finally, we observed the formation of ETE homodimers in solution and the predicted homodimeric structure revealed the participation of a characteristic nonconserved loop in the interface and the partial occlusion of the protein active site, suggesting that monomerization is required for enzymatic activity. 相似文献
7.
Ana Beatriz Aguiar Sanford Leidivan Sousa da Cunha Caio Bezerra Machado Flvia Melo Cunha de Pinho Pessoa Abigail Nayara dos Santos Silva Rodrigo Monteiro Ribeiro Fabiano Cordeiro Moreira Manoel Odorico de Moraes Filho Maria Elisabete Amaral de Moraes Lucas Eduardo Botelho de Souza Andr Salim Khayat Caroline Aquino Moreira-Nunes 《International journal of molecular sciences》2022,23(15)
The circadian clock (CC) is a daily system that regulates the oscillations of physiological processes and can respond to the external environment in order to maintain internal homeostasis. For the functioning of the CC, the clock genes (CG) act in different metabolic pathways through the clock-controlled genes (CCG), providing cellular regulation. The CC’s interruption can result in the development of different diseases, such as neurodegenerative and metabolic disorders, as well as cancer. Leukemias correspond to a group of malignancies of the blood and bone marrow that occur when alterations in normal cellular regulatory processes cause the uncontrolled proliferation of hematopoietic stem cells. This review aimed to associate a deregulated CC with the manifestation of leukemia, looking for possible pathways involving CG and their possible role as leukemic biomarkers. 相似文献
8.
Paula Mendonça Moraes 《LWT》2010,43(9):1320-1324
The objective of this study was to evaluate culture media and methodologies for isolation and detection of lactic acid bacteria (LAB) capable to produce bacteriocin-like substances. Samples of milk and cheese were pour plated on de Mann-Rogosa-Sharpe agar (MRS) and Kang-Fung-Sol agar (KFS) (both at 35 °C/48 h, under anaerobiosis), from which 389 and 256 LAB cultures were selected. The antagonistic activity of them was evaluated using the spot-on-the-lawn and two culture media: brain-heart infusion agar with catalase (BHI + C) and M17 (both at 35 °C/24 h). The proteinaceous nature of the antagonistic cultures was verified using: spot-on-the-lawn (MRS, 25 °C/24 h, under anaerobiosis) and well-diffusion (cultures amplified on modified MRS broth at 25 °C/24 h, and then neutralized using NaOH). Listeria monocytogenes ATCC 7644 was used as indicator. A larger number of antagonist cultures were isolated from MRS (83 by M17 and 65 by BHI + C) in comparison to KFS (24 by M17 and 15 by BHI + C). The spot-on-the-lawn identified a higher frequency of LAB capable of producing bacteriocin-like substances. MRS was considered to be the best culture media for the isolation of LAB capable to produce bacteriocin-like substances, activity that was better identified using the spot-on-the-lawn methodology. 相似文献
9.
K.C. Creutzinger H.M. Dann P.D. Krawczel L.E. Moraes M.D. Pairis-Garcia K.L. Proudfoot 《Journal of dairy science》2021,104(6):7122-7134
In natural settings, dairy cows separate from the herd to give birth. When kept indoors, seeking isolation before calving may be restricted and may depend on space and resources provided in maternity housing. The effect of group maternity pens on behavior around calving and labor progress is unknown. Therefore, the objective of this study was to determine the effects of stocking density and provision of a blind in group bedded pack maternity pens on lying and social behavior as well as length of labor of preparturient dairy animals. The study was conducted as a complete randomized block design with a 2 × 2 factorial arrangement of treatments including stocking density and presence or absence of a blind, resulting in a total of 4 treatments: (1) high stocking density (7.7–12.9 m2 lying space/cow) with a blind, (2) low stocking density (15.4–25.8 m2) with a blind, (3) high stocking density without a blind, and (4) low stocking density without a blind. A total of 127 primiparous heifers and 247 multiparous cows were housed in mixed-parity groups from approximately 3 wk before and immediately after calving. During the 4 h before calving, lying behavior (lying time and bouts) was collected automatically using accelerometers, and social behavior (agonistic interactions, allogrooming, and attention from other cows), stage II labor duration, and frequency of position change during stage II labor were collected using video. Lying behavior was collected with accelerometers. Regardless of treatment, lying time and bouts increased as calving approached. Cows and heifers performed more lying bouts in low stocking density pens compared with high stocking density pens. Agonistic interactions and allogrooming were not different between treatments. Other cows spent more time paying attention to focal animals regardless of stocking density as calving approached, but time spent paying attention was reduced by the presence of a blind during h ?2 before calving. The hazard of calving unassisted was greater for cows and heifers in low stocking density pens with a blind compared with all other treatments. Further, animals in pens with a blind tended to change positions fewer times during stage II labor. These results suggest that providing a blind in group maternity pens may improve the calving environment for cows and heifers and, in combination with low stocking density, may reduce the amount of time spent in labor. 相似文献
10.
Maria Eliza de Castro Moreira Rosemary Gualberto Fonseca Alvarenga Pereira Danielle Ferreira Dias Vanessa Silva Gontijo Fabiana Cardoso Vilela Gabriel de Oliveira Isac de Moraes Alexandre Giusti-Paiva Marcelo Henrique dos Santos 《Journal of Functional Foods》2013,5(1):466-474
Green coffee contains a large quantity and variety of polyphenols and flavonoids. The roasting affects the composition of the polyphenols in coffee, due to the formation of compounds generated by Maillard reaction, which can have anti-inflammatory or antioxidant potential. The anti-inflammatory and antioxidant effects of aqueous extracts of green (AGCa) and roasted (ARCa) coffee beans were investigated in animal models and using a DPPH radical scavenging test. In the formalin test the extracts reduced licking activity only in the late phase. The inhibitory values of oedema at 3 h post-carrageenan were 53% and 74% for 100 and 300 mg/kg of the AGCa extract and 36% for ARCa (300 mg/kg). Leukocyte recruitment into the peritoneal cavity was inhibited by the extracts. The antioxidant activities of the extracts were higher than the reference antioxidants, ascorbic acid and butylated hydroxytoluene. These results indicate that coffee extracts exhibit anti-inflammatory and antioxidant properties. 相似文献