Efficient,high photostability,high brightness,co-polymer solid state dye lasers

Abstract

We report an investigation of the laser beam quality, efficiency and photostability of rhodamine 590 solid state dye lasers with hosts based upon 2-hydroxyethylmethacrylate and methylmethacrylate P(HEMA:MMA) co-polymers and modified methylmethacrylate (MPMMA) polymers with ethanol and dimethylsulphoxide additives. Highest efficiencies were obtained with MPMMA, with slope efficiencies of up to 44% (corresponding to 61% optical-optical conversion) measured for ethanolic MPMMA. P(HEMA:MMA) hosts gave superior photostability, with the highest normalized photostability of 240 GJ mol^?1 obtained for a P(HEMA:MMA) 1:1 rod. A simple resonator has been used to compensate the effects of thermal lensing and pump mode-mismatch, resulting in optimized beam quality for MPMMA lasers.     

Effect of Heat-Generating Solid Body on Mixed Convection Flow in a Ventilated Cavity

The mixed convection flow and heat transfer characteristics inside a square ventilated cavity with a heat-generating solid circular body located at the center have been investigated numerically. The inlet opening is at the bottom of the left wall, while the outlet one is at the top of the right wall, and all the walls of the cavity are considered to be adiabatic. A Galerkin weighted residual finite element method is used to solve the governing equations of mass, momentum, and energy. The behavior of the fluid in the ranges of dimensionless cylinder diameter from 0.1 to 0.6 of the heat generating body, thermal conductivity ratio range from 0.2 to 50 between solid and fluid, and heat generating parameter range from 1 to 5 is described in detail. The medium considered is air with a Prandtl number of 0.71. It is found that the flow and temperature field is strongly dependent on the already-mentioned parameters for the ranges considered. The variation of the mean Nusselt number, the dimensionless average drag force, and the average temperature of the fluid versus Richardson number are presented for these parameters.     

Using chemical reactivity to provide insights into environmental transformations of priority organic substances: the Fe⁰-mediated reduction of Acid Blue 129

Sulfonated anthracenedione dyes are medium priority organic compounds targeted for environmental assessment under the Government of Canada's Chemical Management Plan (CMP). Since organic compounds undergo transformations in environmental matrices, understanding these transformations is critical for a proper assessment of their environmental fate. In the current study, we used zero-valent iron (ZVI) to provide insight into reductive transformation processes available to the anthracenedione dye, Acid Blue 129 (AB 129), a dye which is used in the textile industry. At high temperatures, we found that AB 129 was rapidly reduced (within 3 h) after being adsorbed onto the ZVI-surface, whereupon decomposition took place via multiple competitive and consecutive reaction pathways. Reaction products were identified using state-of-the-art accurate mass Liquid Chromatography-Quadrupole Time of Flight-Mass Spectroscopy (LC-QToF-MS). Five transformation products were identified, including a genotoxic (and thus, potentially carcinogenic) end-product, 2,4,6-trimethylaniline. The same products were found at room temperature, demonstrating that the transformation pathways revealed here could plausibly arise from biological and/or environmental reductions of AB 129. Our results demonstrate the importance of identifying reaction product arising from priority substances as part of the environmental risk assessment process.     

An evaluation of the prognostic significance of antigen CD95(Fas/APO-1) expression on the cells of patients with a myelodysplastic syndrome, acute myeloid leukemia and chronic myeloleukemia

AIM: The expression of CD95(Fas/APO-1) antigen was studied on bone marrow cells of 19 MDS patients, peripheral blood blast cells of 15 acute myeloid leukemia (AML) patients, blast cells and granulocytes of 68 patients with chronic myeloid leukemia (CML)--24 in chronic, 9 in accelerated phase and 35 in blastic crisis (BC)--by indirect surface immunofluorescence assay using flow cytometry (FACScan, Becton Dickinson, USA). RESULTS: CD95(Fas/APO-1) antigen was revealed on bone marrow cells of 8 out of 19 (36.8%) MDS patients; the percentage of antigen-positive cells was 38.1 +/- 19.2%; on 45.5 +/- 22.8% of cells in 6(45%) of 15 AML patients. Fas/APO-1 antigen was totally absent in CML chronic stage; its expression was found in 34% (12 of 35) of our patients with CML BC on peripheral blood blasts and in 56% (5 of 9) on peripheral blast cells of CML patients in acceleration phase. CONCLUSION: The data on overall survival of CD95-positive MDS patients suggest that the presence of Fas antigen is a favorable prognostic sign for patients with MDS. The patients from CD95-negative group represent a risk group both for survival and AML transformation. In CML BC group the survival does not depend upon Fas-antigen expression.     

Replication of dimensions of locus of control.

Employed 120 male and 113 female undergraduates in a replication of H. L. Mirels's (see record 1970-10386-001) study which found 2 factors in analyzing responses to 23 items on Rotter's Internal-External Control Scale. The same polar dimensions of "luck" as the arbiter of life events as opposed to personal control were found as well as a 2nd dimension of degree of control over political and social institutions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of marinating time and low pH on marinade performance and sensory acceptability of poultry meat

The effects of marinating time (30, 60, 120 and 180 min) and acidic marinade pH (3.0, 3.2, 3.4, 3.6, 3.8, 4.0 and 4.2) on the instrumental and sensory properties of cooked Chinese-style marinated chicken were investigated. With increasing marinating time up to 180 min, a significant (P < 0.05) increase in surface redness (a∗ value) and the dark pink sensory attribute was observed, along with a corresponding decrease in lightness (L∗ value) and colour penetration. Increased marinating times of 120–180 min were found to produce more acceptable end products with increased scores for colour, aroma and flavour attributes. Marinade uptake was greater at higher marinade pH levels of 3.8, 4.0 and 4.2, with the highest marinade uptake (3.34%) recorded at pH 4.0. As changes to core meat pH were not observed, the effect of marinating time (up to 180 min) and marinade pH on the instrumental and sensory properties of Chinese-style marinated chicken were located principally at the surface of samples. Consumers considered surface colour as contributing to acceptability of marinated chicken to a greater degree compared to colour penetration.     

PET/EVA/PP ternary blends: An investigation of extended morphological properties

In this study, the effects of different parameters on the morphological properties of ternary blends were investigated. Therefore two systems (PET/H‐EVA/PP and PET/L ‐EVA/PP, H‐EVA and L ‐EVA are high and low viscosity, respectively) were prepared by melt mixing process. In all of the blends, poly (ethylene terephthalate) (PET) as the major phase‐ with poly propylene (PP) and two grades of poly (ethyl‐stat‐vinylacetate) (EVA) with different viscosities and subsequently different interfacial interactions was blended. Theoretical models predicted positive spreading coefficient for two grades of EVA and lower free energy for the samples consisting of EVA and PP as the shell and the core phases respectively. With changing core shell ratio, droplet size of samples containing L ‐EVA and H‐EVA increased and decreased, respectively. Subinclusion of shell into the core was observed in some blended samples. In systems containing H‐EVA, by thickening the shell phase; multi core morphology was observed which would be related to the coalescence phenomenon inter the droplets. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009