Effects of Microstructure Formation on the Stability of Vapor Deposited Glasses

Glasses formed by physical vapor deposition (PVD) are an interesting new class of materials, exhibiting properties thought to be equivalent to those of glasses aged for thousands of years. Exerting control over the structure and properties of PVD glasses formed with different types of glass-forming molecules is now an emerging challenge. In this work, we study coarse grained models of organic glass formers containing fluorocarbon tails of increasing length, corresponding to an increased tendency to form microstructures. We use simulated PVD to examine how the presence of the microphase separated domains in the supercooled liquid influences the ability to form stable glasses. This model suggests that increasing molecule tail length results in decreased thermodynamic and kinetic stability of the molecules in PVD films. The reduced stability is further linked to the reduced ability of these molecules to equilibrate at the free surface during PVD. We find that as the tail length is increased, the relaxation time near the surface of the supercooled equilibrium liquid films of these molecules are slowed and become essentially bulk-like, due to the segregation of the fluorocarbon tails to the free surface. Surface diffusion is also markedly reduced due to clustering of the molecules at the surface. Based on these results, we propose a trapping mechanism where tails are unable to move between local phase separated domains on the relevant deposition time scales

Notes concerning the semi-terrestrial and freshwater amphipods (Crustacea : Peracarida) of the Maltese Islands

Interest in Mediterranean amphipods has been re-focused recently by the appearance of a new multi-author monograph on the group edited by Professor Sandro Ruffo (1982 and continuing) which, when complete, will replace the classic work of Chevreux & Fage (1925). In spite of this progress, however, wide areas of the Mediterranean are still almost unknown amphipodologically (Ruffo (ed.), 1982) and detailed fauna lists are wanting for many regions. For the past few years, one of us (P.I.S.) has been surveying bodies of freshwater in the Maltese Islands and samples have now been amassed from all the main fresh- and brackish water sites in the islands. Since just about every body of freshwater dries up early in the summer (and remains so for the best part of six months each year) it is interesting to see just how many amphipod species the islands' freshwaters support. Since present knowledge of Maltese semi-terrestrial amphipods is also limited they too have been included in our surveys. The following list summarizes our taxonomic (P.G.M.) and ecological (P.I.S.) knowledge of the Amphipoda from these habitats on the Maltese Islands. All material is deposited in the personal collections of P.I.S. with the exception of Allorchestes aquilinus (A. Costa) which is in the collections of P.G.M.peer-reviewe

Novel needle cutting edge geometry for end‐cut biopsy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135111/1/mp5253.pd

Tobacco exposure inhibits SPLUNC1-dependent antimicrobial activity

Background: Tobacco smoke exposure impairs the lung´s innate immune response, leading to an increased risk of chronic infections. SPLUNC1 is a secreted, multifunctional innate defense protein that has antimicrobial activity against Gram negative organisms. We hypothesize that tobacco smoke-induced SPLUNC1 dysfunction contributes to the observed defect in innate immunity in tobacco smokers and that this dysfunction can be used as a potential biomarker of harm. Methods: We collected sputum from never-smokers and otherwise healthy smokers. We performed Western blotting to determine SPLUNC1 levels and determined antimicrobial activity against nontypeable Haemophilus influenzae. An in vitro exposure model was utilized to measure the effect of tobacco exposure on human bronchial epithelial culture (HBEC) antimicrobial activity against H. influenzae. The direct effects of cigarette and little cigar smoke exposure on SPLUNC1 function was determined using 24 h growth measurements and LPS binding assays. Results: H. influenzae growth in cigarette smoker´s sputum was significantly greater compared to never-smokers sputum over 24 h. HBEC supernatants and lysates contained significantly higher numbers of H. influenzae following chronic cigarette and little cigar smoke exposure compared to air-exposed controls. Furthermore, SPLUNC1´s antimicrobial activity and LPS-binding capability against both H. influenzae and P. aeruginosa was attenuated following cigarette and little cigar exposure. Conclusions: These data suggest that cigarette and little cigar exposure impairs SPLUNC1´s antimicrobial ability and that this inhibition may serve as a novel biomarker of harm that can be used to assess the toxicity of commercial tobacco products.Fil: Moore, Patrick J.. University of North Carolina; Estados UnidosFil: Sesma, Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Médicas; ArgentinaFil: Alexis, Neil E.. University of North Carolina; Estados UnidosFil: Tarran, Robert. University of North Carolina; Estados Unido

The Sacred Geography of Dawei: Buddhism in peninsular Myanmar (Burma)

The paper opens by recounting the beginnings of Buddhism in Dawei as preserved in local chronicles and sustained in stupas marking the episodes of the chronicle narrative. The chronicles start with a visit of the Buddha whose arrival triggers a series of events bringing together pre-existing tutelary figures, weiza, a hermit and offspring born of a golden fish, culminating in the establishment of the first Buddhist kingdom circa the eighth to tenth century CE. The enshrinement of sacred hairs gifted by the Buddha also includes patronage by a king of the ‘Suvannbhumi’ lineage. Associated with the monks Sona and Uttara from Sri Lanka sent by King Asoka’s son Mahinda, ‘Suvannbhumi’ literally can refer to the archaeology of Thaton, a walled site in the present day Mon State, or, as is the case here, more widely to the missionary tradition associated with Asoka (Sao Saimong Mengrai 1976). The third story in the establishment of the Buddhist king at Thagara is the longest of the chronicle, the tale of a royal hunter who failed to capture a golden peacock for the queen. The hunter became a hermit living by a pond with a golden fish and as he urinated in the pond, two children were born from the fish. The boy becomes the first Buddhist king of Thagara, 11 km north of Dawei, where artefacts from survey and excavation confirm the chronology of the chronicle, with the closest archaeological parallels found not at the ancient sites of the Mon State but to the first millennium CE Buddhist ‘Pyu’ heritage of Upper Myanmar which is notably absent in the chronicle compilation

Laser machined macro and micro structures on glass for enhanced light trapping in solar cells

In order to increase the efficiency of solar cell modules it is necessary to make the optimum use of light incident upon them. Much research has been done on improving light absorption through front surface texturisation and light trapping schemes. Laser light is commonly used in industry for various applications including marking and texturisation. By controlling laser parameters, it is possible to tailor macro and micro structures in most materials. The CO2 laser used in this investigation emits radiation at 10.6 μm with the ability to pulse in the micro-second range. The laser was used to ablate grooved textures in the fused quartz material, used in this study as the light trapping medium, following which an analysis of the effects of the laser parameters on the texture geometry and surface morphology was performed through a combination of cross sectioning and scanning electron microscopy. Transmission through the textured glass was improved for most samples after acid etching. The light trapping effects of the best performing textures were analysed by investigating the effects on a silicon solar cell’s performance at varying angles of incidence. Results indicated a significant increase in light trapping when light was incident at acute angles. For an angle of incidence of 10◦ a relative increase in efficiency of up to 51 % was observed