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排序方式: 共有196条查询结果,搜索用时 203 毫秒
111.
Saraví M Zaretzky A Lindner C Díaz J Walwyn G Amorim R De Souza D Gregori B Papadópulos S Meghzifene A Ferruz P Suárez RC 《Radiation protection dosimetry》2007,125(1-4):84-87
Several intercomparison exercises were organised by the International Atomic Energy Agency (IAEA) on the determination of operational quantities at the regional or interregional basis. In the Latin American region an intercomparison for the determination of the operational quantity Hp(10) was completed mid-2004, as a follow-up to previous exercises carried out during the 1990s. Eighteen individual external monitoring services from nineteen Member States participated in the first phase. The second phase grouped 15 services that had participated in the first phase. Dosemeter irradiations in photon beams were done by four Secondary Standard Dosimetry Laboratories (SSDLs) of the region. The preparation of this exercises involved an audit by the IAEA SSDL, where reference irradiations were provided to all participants for verification of their systems. During the first phase (2002-2003) only 9 out of 18 services met the performance requirements for such monitoring services. Necessary corrective actions and procedure verification were implemented. During the second phase (2004) 11 out of 15 services fulfilled the performance criteria. This intercomparison shows that there has been improvement in the second phase and most participants demonstrated a satisfactory performance of the quantity tested. 相似文献
112.
The effects of blend compatibility caused by compatibilizing agents were studied by microscopy, thermal analysis, and nuclear magnetic resonance (NMR) spectroscopy (carbon-13 NMR spectra and proton spin-lattice relaxation time) of homopolymers and polymer blends. In this study the results obtained by all measurements are discussed in terms of molecular mobility and compatibility, as a consequence of changes in the microdomains. © 1996 John Wiley & Sons, Inc. 相似文献
113.
本文报道了一种利用两步热丝化学气相沉积法来提高金刚石薄膜质量的方法,在Si(100)基体上获得了面积45cm^2、厚度60μm的金刚石薄膜。第一步是在HFCVD反应室生长CVD金刚石薄膜,第二步是利用H2SO4:CrO3的饱和溶液对样品进行处理,再用H2O2:NH4OH(1:1)溶液冲洗干净,处理之后再沉积第二层金刚石薄膜。利用SEM、拉曼光谱、XPS分析金刚石薄膜。结果表明,薄膜厚度达60μm,纯度很高,并且在整个面积上是均匀的。 相似文献
114.
Romulo Monteiro Callado Joao Reinaldo Imbiriba da Rocha Junior Antonio Felisberto P. Amorim 《能源与动力工程:英文版》2014,(7):1203-1209
The installation of wind power generators on buildings located in areas with regular winds may be a suitable investment in a renewable power source. Brazil has a high eolic potential, where the annual mean wind speed may reach over eight meters per second. This case study is aimed to assess the economic feasibility of the installation of small wind power plants in urban areas. This work evaluates a project for the installation of a vertical axis wind turbine in three buildings (15-, 22-, and 26-story) including the following stages: (1) installation of a real-time power meter in the 15-store unit; (2) demand analysis of the 26-store building's power consumption; (3) winds survey along the coast of the State of Ceara; (4) analysis of the wind turbines available in the market; (5) simulation aimed to choose the system. Vertical wind power generators offer better conditions of use in urban areas. The turnover time was established to be between four and six years in the three studied units. The installation of a wind power generator on buildings in regions with an adequate eolic regimen reaches a financial return of the investment before the end of the equipment's lifespan. 相似文献
115.
Eduardo Lucena Cavalcante de Amorim Aruana Rocha Barros Márcia Helena Rissato Zamariolli Damianovic Edson Luiz Silva 《International Journal of Hydrogen Energy》2009
This study evaluated hydrogen production in an anaerobic fluidized bed reactor (AFBR) fed with glucose-based synthetic wastewater. Particles of expanded clay (2.8–3.35 mm) were used as a support material for biomass immobilization. The reactor was operated with hydraulic retention times (HRT) ranging from 8 to 1 h. The hydrogen yield production increased from 1.41 to 2.49 mol H2 mol−1 glucose as HRT decreased from 8 to 2 h. However, when HRT was 1 h, there was a slight decrease to 2.41 mol H2 mol−1 glucose. The biogas produced was composed of H2 and CO2, and the H2 content increased from 8% to 35% as HRT decreased. The major soluble metabolites during H2 fermentation were acetic acid (HAc) and butyric acid (HBu), accounting for 36.1–53.3% and 37.7–44.9% of total soluble metabolites, respectively. Overall, the results demonstrate the potential of using expanded clay as support material for hydrogen production in AFBRs. 相似文献
116.
Helena P. Felgueiras Marta A. Teixeira Tânia D. Tavares Natália C. Homem Andrea Zille M. Teresa P. Amorim 《应用聚合物科学杂志》2020,137(18):48626
Poly(vinyl alcohol)/cellulose acetate (PVA/CA) films were prepared via a new method that combines principles from solvent casting and phase inversion. To guarantee some degree of flexibility, films were produced with a higher percentage of PVA compared to CA, from 90/10 to 50/50. The antimicrobial peptide (AMP) LL37 was then anchored using dopamine as a binding agent. Films were characterized in terms of functional groups, thermal stability, tensile strength, porosity, swelling, and degradation (stability in physiological media at different pHs). The antimicrobial performance of LL37 surface-modified films was tested against Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli in dynamic environment and in the presence and absence of an albumin interface. LL37 treated films demonstrated great antibacterial efficacy against the three kinds of bacteria, ≈75% inhibition for S. aureus, ≈85% for S. epidermidis, and ≈60% for E. coli, regardless of PVA/CA ratio. Presence of albumin reduced bacteria inhibition in all tested groups, most likely due to the binding of the protein molecules to the antimicrobial agents, reducing the free fraction available for bacterial killing. Films treated with LL37 accelerated clotting time (≈10 min) above vancomycin and bare surfaces, demonstrating great capacity to activate the intrinsic coagulation cascade. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48626. 相似文献
117.
Synthesis,DNA Binding,and Antiproliferative Activity of Novel Acridine-Thiosemicarbazone Derivatives
Sinara M?nica Vitalino de Almeida Elizabeth Almeida Lafayette Lúcia Patrícia Bezerra Gomes da Silva Cézar Augusto da Cruz Amorim Tiago Bento de Oliveira Ana Lucia Tasca Gois Ruiz Jo?o Ernesto de Carvalho Ricardo Olímpio de Moura Eduardo Isidoro Carneiro Beltr?o Maria do Carmo Alves de Lima Luiz Bezerra de Carvalho Júnior 《International journal of molecular sciences》2015,16(6):13023-13042
In this work, the acridine nucleus was used as a lead-compound for structural modification by adding different substituted thiosemicarbazide moieties. Eight new (Z)-2-(acridin-9-ylmethylene)-N-phenylhydrazinecarbothioamide derivatives (3a–h) were synthesized, their antiproliferative activities were evaluated, and DNA binding properties were performed with calf thymus DNA (ctDNA) by electronic absorption and fluorescence spectroscopies. Both hyperchromic and hypochromic effects, as well as red or blue shifts were demonstrated by addition of ctDNA to the derivatives. The calculated binding constants ranged from 1.74 × 104 to 1.0 × 106 M−1 and quenching constants from −0.2 × 104 to 2.18 × 104 M−1 indicating high affinity to ctDNA base pairs. The most efficient compound in binding to ctDNA in vitro was (Z)-2-(acridin-9-ylmethylene)-N-(4-chlorophenyl) hydrazinecarbothioamide (3f), while the most active compound in antiproliferative assay was (Z)-2-(acridin-9-ylmethylene)-N-phenylhydrazinecarbothioamide (3a). There was no correlation between DNA-binding and in vitro antiproliferative activity, but the results suggest that DNA binding can be involved in the biological activity mechanism. This study may guide the choice of the size and shape of the intercalating part of the ligand and the strategic selection of substituents that increase DNA-binding or antiproliferative properties. 相似文献
118.
119.
Raphael Amorim Lorenzoni Ricardo Paris Gasparini Ana Cláudia dos Santos Temístocles de Sousa Luz Marcelo Camargo Severo de Macêdo 《腐蚀工程科学与技术》2019,54(1):62-74
This study aims to evaluate the influence of heat input and dilution on the corrosion behaviour of a weld overlay coating of Inconel 625 deposited using a plasma transferred arc process. Cyclic potentiodynamic polarisation, double-loop electrochemical potentiometric reactivation and critical pitting temperature (CPT) experiments were performed to determine sensitisation and pitting corrosion resistance of the coating, besides microstructural characterisation and microhardness testing. The overlay showed to be resistant to sensitisation in all cases. Within the scope of this study, only the CPT test was able to cause pitting in the alloy, which showed that increments of the specimen's chemical dilution and heat input induced a lower CPT. This is mainly due to different chemical compositions among the distinct phases present in the coating. 相似文献
120.
Laís Ferraz Brito Hellen Braga Martins Oliveira Nathan das Neves Selis Clarissa Leal Silva e Souza Manoel Neres Santos Júnior Erika Pereira de Souza Lucas Santana Coelho da Silva Flávia de Souza Nascimento Aline Teixeira Amorim Guilherme Barreto Campos Márcio Vasconcelos de Oliveira Regiane Yatsuda Jorge Timenetsky Lucas Miranda Marques 《Journal of the science of food and agriculture》2019,99(13):5870-5880