Measurement driven quantum evolution

We study the problem of mapping an unknown mixed quantum state onto a known pure state without the use of unitary transformations. This is achieved with the help of sequential measurements of two non-commuting observables only. We show that the overall success probability is maximized in the case of measuring two observables whose eigenstates define mutually unbiased bases. We find that for this optimal case the success probability quickly converges to unity as the number of measurement processes increases and that it is almost independent of the initial state. In particular, we show that to guarantee a success probability close to one the number of consecutive measurements must be larger than the dimension of the Hilbert space. We connect these results to quantum copying, quantum deleting and entanglement generation.Comment: 7 pages, 1 figur

Efecto de la infusión de Mentha spicata L. en el rendimiento y las características organolépticas de canales de pollos de engorde Cobb 500

[ES] El objetivo de esta investigación fue evaluar el efecto de la infusión de Mentha spicata L. sobre el rendimiento y las características organolépticas de los pollos de engorde Cobb 500. Se siguió el manejo, la bioseguridad y el bienestar de las aves para los sistemas de casas abiertas, utilizando un diseño completamente al azar (CRD). Se utilizaron 200 pollos mixtos de 1 día de edad, para evaluar los efectos de los tratamientos durante 35 días. Se distribuyeron en cinco tratamientos, con cuatro réplicas, de 10 aves cada uno a los siguientes grupos: T1 (control), T2 (infusión de M. spicata al 10%), T3 (infusión de M. spicata al 20%), T4 (Infusión de M. spicata al 30%) y T5 (infusión de M. spicata al 40%). Las variables estudiadas fueron el rendimiento de pollos de engorde, el peso de la canal y las características organolépticas. Los datos se procesaron utilizando el programa estadístico Statgraphics Centurión XV.I, realizando un análisis multivariado de la varianza y determinando los factores con efecto, y un ANOVA por semana para las variables productivas; se elaboraron tablas de contingencia con los datos de los indicadores organolépticos para determinar las diferencias (Prueba de Chi-cuadrado). Los resultados muestran que la administración de M. spicata L. al agua de bebida no tiene efecto sobre el rendimiento de los pollos de engorde, con la excepción del consumo de alimento, que disminuye, lo que refleja un efecto similar sobre el peso visceral. La presencia de flavonoides en la planta disminuyó el grosor de la grasa abdominal porque favorece el metabolismo de los lípidos de las aves. No hubo diferencia en el olor de la carne, sin embargo, hubo diferencias significativas en los parámetros de sabor, terneza y jugosidad.[EN] The objective of this research was evaluate the effect of Mentha spicata L. infusion on the productive performance and organoleptic characteristics of Cobb 500 broilers. The management, biosecurity and welfare of birds for open houses systems were followed using a completely random design (CRD). In order to evaluate treatments effects during 35 days, 200 1-day-old mixed chickens were distributed in five treatments, with four réplicas, of 10 birds each in the following groups: T1 (control), T2 (M. spicata infusion at 10%), T3 (M. spicata infusion at 20%), T4 (M. spicata infusion at 30%) and T5 (M. spicata infusion at 40%). The variables studied were broilers productives performance, carcass weight, abdominal fat and organoleptic characteristics. The data was processed using statistical program Statgraphics Centurión XV.I, performing a multivariate analysis of variance and determining the factors with effect, and ANOVA of productive variables per week; contingency tables were prepared with organoleptic indicators data to determine differences (Chi-square test). Results show no effect on productive parameters up to 30% per liter because a decrease in feed consumption in the slaugther week for T5 (40% of infusion) which indicate a limit of infusion use; the principal effects on infusion M. spicata L was on abdominal fat which was lower thickness in T4 (30%) and T5 (40%) maybe due to the presence of flavonoids in the mint plant, which have a positive effect on lipid metabolism, resulting in a lean product. Flavor, tenderness and juiciness showed a favorable acceptance for meat of animals recibing the infusion treatements in relation to the control group due to the tendency of the majority of the Ecuador population to consume products with markables organoleptics characteristiques coming from animals raised in tradicional form.To the Animal Scientist Doctor Dervin Bartolo Dean Gutiérrez, PHD and Veterinary Medicine Doctor Carlos Armando Alvarez Díaz for his collaboration in writing and translation into the English language of this work.Sanchez-Quinche, A.; Solórzano Saldarriaga, J.; Quevedo Guerrero, J.; Paladines Romero, J.; Pérez Baena, I. (2019). Effect of Mentha spicata L. infusión on the productive performance and organoleptic characteristics of Cobb 500 broilers. Acta Agronómica. 68(4):312-318. https://doi.org/10.15446/acag.v68n4.72174S31231868

Effect of scandium triflate on the RAFT copolymerization of methyl acrylate and vinyl acetate controlled by an acid/base “switchable” chain transfer agent

Modulation of the activity of an acid/base switchable dithiocarbamate RAFT agent, cyanomethyl (4-fluorophenyl)(pyridin-4-yl)carbamodithioate, with the Lewis acid scandium triflate (Sc(OTf)3) was investigated to examine the ability to deliver improved control over RAFT copolymerizations involving both more-activated and less-activated monomers—specifically the copolymerization of methyl acrylate (MA) and vinyl acetate (VAc). The introduction of either 0.5 or 1 mol equiv of Sc(OTf)3, with respect to RAFT agent, into a RAFT copolymerization of MA and VAc provides substantially improved control resulting in significantly reduced molar mass dispersities (Đ) (∼1.1–1.3) than achieved in its absence (Đ ∼ 1.3–1.4). Furthermore, similar introduction of Sc(OTf)3 into MA homopolymerization mediated by the same RAFT agent also delivered polymers of very low Đ (∼1.15). Sc(OTf)3 was also found to lower the rate of polymerization and alter the copolymerization reactivity ratios for MA and VAc. Increasing the Lewis acid concentration provides enhanced incorporation of the less active monomer, VAc, into the copolymers ([Sc(OTf)3]/[RAFT] = 0, rMA = 4.04, rVAc = 0.032; [Sc(OTf)3]/[RAFT] = 0.5, rMA = 3.08, rVAc = 0.17; [Sc(OTf)3]/[RAFT] = 1, rMA = 2.68, rVAc = 0.62). Carbon nuclear magnetic resonance (13C NMR) and differential scanning calorimetry (DSC) analysis of preparative samples confirm the enhanced VAc incorporation with increased levels of Sc(OTf)3. Importantly the inclusion of Sc(OTf)3 does not deleteriously affect the thiocarbonylthio end-groups of the RAFT polymers, with high end-group fidelity being observed in all copolymerizations

The reactivity of N-vinylcarbazole in RAFT polymerization: trithiocarbonates deliver optimal control for the synthesis of homopolymers and block copolymers

This is an accepted manuscript of an article published by Royal Society of Chemistry in Polymer Chemistry on 30/04/2012, available online: https://doi.org/10.1039/C3PY00487B The accepted version of the publication may differ from the final published version.The use of various RAFT agents (ZC(S)SR) including dithiobenzoates (Z = Ph), trithiocarbonates (Z = SR′), xanthates (Z = OR′), and conventional and switchable N-aryldithiocarbamates (Z = NR′Ar) in RAFT polymerization of N-vinylcarbazole (NVC) has been explored with a view to establishing which is most effective. Consistent with earlier work, we find that xanthates and N-aryldithiocarbamates give adequate control (dispersities < 1.3) while dithiobenzoates give marked retardation. However, contrary to popular belief, we find that the polymerization of NVC is best controlled with trithiocarbonate RAFT agents, which provide both good molecular weight control, very narrow dispersities (1.1), and high end-group fidelity. The results demonstrate that NVC has intermediate reactivity, i.e. between that of the traditional more activated (MAMs; styrene, acrylates) and less activated monomers (LAMs; vinyl acetate, N-vinylpyrrolidone). A further key to good control is the selection of RAFT agent R substituent to be both a good leaving group and a good initiating radical. The cyanomethyl group meets these criteria whereas phenylethyl is a poor initiating radical for NVC polymerization. A further demonstration of the intermediate reactivity of NVC and the derived propagating radical was the successful preparation of both poly(n-butyl acrylate)-block-poly(N-vinylcarbazole) and poly(N-vinylcarbazole)-block-poly(n- butyl acrylate) with a trithiocarbonate RAFT agent (the sequence of block synthesis is not important). Two-dimensional, liquid chromatography near critical conditions-gel permeation chromatography (LCCC-GPC) has been applied to demonstrate block purity. The corresponding styrene-based blocks can also be successfully synthesized, however, the reinitiation of NVC polymerization by the polystyryl radical proved to be a constraint on the purity of polystyrene-block-poly(N-vinylcarbazole). © 2013 The Royal Society of Chemistry.The authors gratefully acknowledge the Capability Development Fund of CSIRO Materials Science and Engineering for financial support. D.J.K. acknowledges the Office of the Chief Executive of CSIRO for an OCE postdoctoral fellowship and the School of Science and Technology at the University of New England for a start-up grant.Published versio

The constant-velocity highly collimated outflows of the planetary nebula He 2-90

We present high-dispersion echelle spectroscopic observations and a narrow-band [N II] image of the remarkable jet-like features of He 2-90. They are detected in the echelle spectra in the H-alpha and [N II] lines but not in other nebular lines. The [N II]/H-alpha ratio is uniformly high, ~1. The observed kinematics reveals bipolar collimated outflows in the jet-like features and shows that the southeast (northwest) component expands towards (away from) the observer at a remarkably constant line-of-sight velocity, 26.0+-0.5 km/s. The observed expansion velocity and the opening angle of the jet-like features are used to estimate an inclination angle of ~5 degrees with respect to the sky plane and a space expansion velocity of ~290 km/s. The spectrum of the bright central nebula reveals a profusion of Fe lines and extended wings of the H-alpha line, similar to those seen in symbiotic stars and some young planetary nebulae that are presumed to host a mass-exchanging binary system. If this is the case for He 2-90, the constant velocity and direction of the jets require a very stable dynamic system against precession and warping.Comment: 8 pages (emulate ApJ), 5 figure, 1 tabl