Verification by tests of models proposed for synchronous machines, excitation control systems, water supply and turbines and its control systems for colbún and machicura power plants

In this paper several models proposed for Excitation Control Systems, Synchronous Machines, Prime Movers Control System and Turbines corresponding to the Hydraulic power plants of Colbún and Machicura are shown and verified. These power plants are located in the “Interconnected Central System” (SIC), Chile’s largest grid and are part of the Colbún subsystem. This grid subsystem also bears industrial load. It supplies energy to “El Teniente” -world’s largest copper mineand to several paper manufacturing plants. The models were used to study the Colbún subsystem under island operation when the SIC blacks out due to under-frequency conditions.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE

Antimutagenic effect of Phyllanthus orbicularis against γ-radiation

The present work evaluated the protective effect of aqueous extract of Phyllanthus orbicularis against the mutagenicity of γ-radiation. The extract activity was determined in pre- and post-treatment procedures using Salmonella reversion assay. In either case, the plant extract protected bacterial cells against the mutations induced by γ-radiation, suggesting that it contains antimutagenic compounds which confer protection by at least two different mechanisms: i) as antioxidants targeting the oxidative mutagens induced by γ-radiation and ii) by modulation of the cellular repair enzymes acting on damaged DNA. The results are discussed in relation to the chemopreventive and radioprotective potential of P. orbicularis.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Crecimiento de la sardina Sardina pilchardus (Walbaum, 1792) en cautividad durante los primeros 18 meses de vida

Larvas de Sardina pilchardus (Walbaum, 1792), nacidas a partir de huevos lecundados en el mar, lueron culñvadas en un tanque de 10 000 L utilizando como presa nauplios de Arlemia sp. y zooplancton vivo durante las dos primeras semanas y, posteriormente, metanauplios de artemia enriquecidos con lsochrysis galbana Parke, 1949. Desde el tercer mes de vida hasta los 18 meses se suminislró un pienso seco (GemmaO.4 yO.a). la longijud total alcanzada al año de vida lue de 162.02±9.49 mm; talla que se correspondió con un peso húmedo de 36.12± 10.82 g. la longitud total a los 18 meses de edad lue de 182.37 mm. Es la primera vez que se describe una experiencia de cultivo de sardina de duración tan prolongada; los datos aportados pueden ser una herramienta útil para definir el crecimiento de la especie y su posible interés comocandidata para la acuicultura marina.Larvae 01 Sardina pilchardus (Walbaum, 1792), bom in captivity from wild lertilized eggs, were grown in a tank 01 1O000 L using Artemiasp. nau~ii and live zooplankton as prey during tIle lirst two weeks, and tIlereafter artemia metanauplius enriched with Isochrysis galbana Parke, 1949. A dry leed (Gemma 0.4 and 0.8) was supplied lrom tIle tIlird monlh until18 montlls old. The lotallength reached al one year 01Iffe was 162.02 ± 9.49 mm, corresponding with a wet weight 01 36.12 ± 10.82 g. The totallength at 18 months 01 age was 182.37 mm. A long experiment 01sardine culture is described lor tIle lirst time; data reported can be a uselul tool lO deline tIle growth 01 the species and its potential interest as candidate lor marine aquaculture

Kinetics of the Strain-Promoted Oxidation-Controlled Cycloalkyne-1,2-quinone Cycloaddition: Experimental and Theoretical Studies

Stimulated by its success in both bioconjugation and surface modification, we studied the strain-promoted oxidation-controlled cycloalkyne-1,2-quinone cycloaddition (SPOCQ) in three ways. First, the second-order rate constants and activation parameters (ΔH⧧) were determined of various cyclooctynes reacting with 4-tert-butyl-1,2-quinone in a SPOCQ reaction, yielding values for ΔH⧧ of 4.5, 7.3, and 12.1 kcal/mol, for bicyclo[6.1.0]non-4-yne (BCN), cyclooctyne (OCT), and dibenzoazacyclooctyne (DIBAC), respectively. Second, their reaction paths were investigated in detail by a range of quantum mechanical calculations. Single-configuration theoretical methods, like various DFT and a range of MP2-based methods, typically overestimate this barrier by 3-8 kcal/mol (after inclusion of zero-point energy, thermal, and solvation corrections), whereas MP2 itself underestimates the barrier significantly. Only dispersion-corrected DFT methods like B97D (yielding 4.9, 6.4, and 12.1 kcal/mol for these three reactions) and high-level CCSD(T) and multireference multiconfiguration AQCC ab initio approaches (both yielding 8.2 kcal/mol for BCN) give good approximations of experimental data. Finally, the multireference methods show that the radical character in the TS is rather small, thus rationalizing the use of single-reference methods like B97D and SCS-MP2 as intrinsically valid approaches

Verification by tests of models proposed for synchronous machines, excitation control systems, water supply and turbines and its control systems for colbún and machicura power plants

In this paper several models proposed for Excitation Control Systems, Synchronous Machines, Prime Movers Control System and Turbines corresponding to the Hydraulic power plants of Colbún and Machicura are shown and verified. These power plants are located in the “Interconnected Central System” (SIC), Chile’s largest grid and are part of the Colbún subsystem. This grid subsystem also bears industrial load. It supplies energy to “El Teniente” -world’s largest copper mineand to several paper manufacturing plants. The models were used to study the Colbún subsystem under island operation when the SIC blacks out due to under-frequency conditions.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE