Local and external factors affecting the photodegradation of 4N,N \u27-dimethylamino-4 \u27 nitrostilbene polymer films

The photodegradation of the electro-optic chromophore 4N,N\u27-dimethylamino-4\u27nitrostilbene was investigated as a function of wavelength, temperature, local atmosphere, and local molecular environment, i.e., attached as a side chain to a polymer or dissolved as a guest in a host polymer

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Systematic Wavelength Dependence Of The Photodegradation Of Polymers Doped With Electro-Optic Chromophores

Photobleaching of electrooptic chromophore doped polymers exhibits a characteristic dependence of the photostability figure of merit versus the photon energy. Such characterization experiments, together with the growing understanding of the different molecular parameters should lead to materials with improved photostability and thus devices with longer lifetimes

Systematic Behavior Of Electro-Optic Chromophore Photostability

The wavelength dependence of the one-photon absorption-induced photodegradation rate has been measured from the visible to the near IR for a variety of electro-optic chromophore-doped polymers. Systematic behavior is identified. The lifetime of the electro-optic activity is found to increase exponentially over 4-6 orders of magnitude for wavelengths ranging from peak of absorption, typically in the visible, to ∼1000 nm. Many popular chromophores developed for electro-optics over the past 10 years are compared. © 2000 Optical Society of America

Effect Of Temperature And Atmospheric Environment On The Photodegradation Of Some Disperse Red 1-Type Polymers

The photodegradation of the azobenzene chromophore DR1 {4-[N-ethyl-N-(2-hydroxyethyl)amino]-4′-nitroazobenzene]} incorporated as a side chain or as a guest in a poly(methyl) methacrylate host has been evaluated as a function of wavelength, temperature, and the atmospheric environment. The effects of these variables on the lifetime of DR1-based electro-optic devices is quantified. © 1999 Optical Society of America

Photodegradation Of Azobenzene Nonlinear Optical Chromophores: The Influence Of Structure And Environment

The influence of structure and environment on the photodegradation of azobenzene nonlinear optical chromophores was discussed. The variables influencing the rate of degradation included chromophore, host polymer structure, irradiation wavelength, temperature and atmosphere. Investigations in different gaseous environment were selectively used to elucidate the role of different degradation mechanisms

Lifetime of electro-optic polymeric devices

The photostability of different electro-optic dye-doped polymeric materials was studied. The well-known and widely used materials such as the stilbene chromophore DANS or the azo chromophore DR1 were found to fall short of the necessary specification required for long-term device operation. The effect of the chromophore structure, varying temperature and atmospheric conditions, and different polymer matrices on the lifetime of electro-optic polymeric devices is discussed

Algoritmo PSO-Híbrido para solucionar el problema de ruteo de vehículos con entrega y recolección simultáneas

Se presenta la metaheurística de Optimización de Enjambre de Partículas (PSO) para la solución del Problema de Ruteo de Vehículos con Entrega y Recolección Simultáneas (VRPSPD). Se aplica una representación de la solución y un método de decodificación para implementar el PSO al VRPSPD. El método de decodificación inicia transformando una partícula en una lista de prioridades de clientes para entrar a las rutas y en una matriz de prioridades de vehículos para servir cada cliente. Las rutas de los vehículos son construidas con base en la lista de prioridad de clientes y en la matriz de prioridad de vehículos. El algoritmo es validado usando 18 instancias disponibles en la literatura para problemas de 100, 200 y 400 clientes

Effect of temperature and atmospheric environment on the photodegradation of some Disperse Red 1 type polymers

International audienceThe photodegradation of the azobenzene chromophore DR1 {4-[N-ethyl-N-(2-hydroxyethyl)amino]-4'- nitroazobenzene]} incorporated as a side chain or as a guest in a poly(methyl) methacrylate host has been evaluated as a function of wavelength, temperature, and the atmospheric environment. The effects of these variables on the lifetime of DR1-based electro-optic devices is quantifie