High resolution, low temperature photoabsorption cross-section of C2H2 with application to Saturn's atmosphere

New laboratory observations of the VUV absorption cross-section of C2H2, obtained under physical conditions approximating stratospheres of the giant planets, were combined with IUE observations of the albedo of Saturn, for which improved data reduction techniques have been used, to produce new models for that atmosphere. When the effects of C2H2 absorption are accounted for, additional absorption by other molecules is required. The best-fitting model also includes absorption by PH3, H2O, C2H6 and CH4. A small residual disagreement near 1600 A suggests that an additional trace species may be required to complete the model

A Study of the Bogdanov-Takens Bifurcation

A two paraIlleter versal tmfolding for generic nilpotent singular point was studied independently by Takens and Bogdanov and so one now calls it : the Bogdanov-Takens bifurcation. Historically, it was the last codiInension 2 singularity to be treated

Procjena prošlih promjena u okolišu proučavanjem sedimenata u hiperslanoj laguni

Carbon and oxygen isotopes, organic matter elemental composition, and mineralogy of carbonates were used as proxies to investigate environmental changes recorded in the carbonate-rich sediment of the hypersaline lagoon "Vermelha", Rio de Janeiro. Isotopic and other data suggest that two striking shifts in environmental conditions occurred about 1900 and 3200 years ago. Carbonates δ(18O) and δ(13C) were found in the range of +1.5‰ to +4.5 ‰ (PDB), and –2 ‰ to –11‰ (PDB), respectively. In organic matter, δ(13C) ranged from –22 ‰ to –15 ‰ (PDB). Calcites and dolomites are present in the studied core; their relative abundance seems to be related to the observed changes. Calcites are enriched up 38 % in MgCO3 (mole fraction, x). As distinct from calcites with lower magnesium contents, Mg-calcite with x(Mg) > 20 % shows an additional peak at 0.2929 nm in the X-ray diffractogram. Samples that contain Mg-calcite or 100 % dolomite show similar δ(13C) values. There are strong indications for an early formation of dolomite already in the microbial mat region. 18O and 2H determinations in lagoon water confirm evaporation as the water balance controlling processU radu je opisana uporaba izotopa ugljika i kisika, elementnog sastava organske tvari i mineralogije karbonata kao faktora u istraživanju promjena na okolišu utvrđenih u karbonatom bogatim sedimentima hiperslane lagune "Vermelha" kod Rio de Janeira u Brazilu. Izotopski i drugi podaci ukazuju na dvije značajne promjene okolišnih uvjeta, koje su se dogodile prije 1900 odnosno 3200 godina. U karbonatima, vrijednosti δ(18O) i δ(13C) izmjerene su u rasponu od +1,5 ‰ do +4,5 ‰, odnosno od –2 ‰ do –11 ‰ (standard Pee Dee Belemnite – PDB). Kod organske tvari, vrijednost δ(13C) varira u rasponu od –22 ‰ do –15 ‰ (PDB). U istraživanoj su sedimentnoj jezgri utvrđeni kalcit i dolomit, a njihova relativna zastupljenost povezana je s utvrđenim okoliš nim promjenama. Kalciti sadrže do 38 % MgCO3 (molni udjeli, x). Za razliku od kalcita s nižim sadržajem magnezija, magnezijev kalcit (x(Mg) > 20 %) pokazuje dodatnu liniju na rendgenskom difraktogramu kod 2929 nm. Uzorci koji sadrže magnezijev kalcit ili čisti dolomit pokazuju slične vrijednosti δ(13C). Postoje snažne indicije za stvaranje dolomita već u području mikrobnih pokrova. Vrijednosti 18O i 2H u vodi lagune ukazuju na to da je isparavanje proces koji kontrolira bilancu vode u sustavu

Promoting independent learning skills using video on digital language laboratories

This is the author's PDF version of an article published in Computer assisted language learning ©2006. The definitive version is available at http://www.informaworld.com/The article discusses the potential for developing independent learning skills using the digital language laboratory with particular reference to exploiting the increasingly available resource of digital video. It investigates the potential for recording and editing video clips from online sources and digitalising clips from analogue recordings and reflects on the current status quo regarding the complex copyright regulations in this area. It describes two pilot self-access programmes based on video clips which were undertaken with University College Chester undergraduates and reflects on the value of the experience for students in developing a wide range of language skills as well as independent learning skills using their feedback on the experience

Titan cell production in Cryptococcus neoformans reshapes the cell wall and capsule composition during infection

This work was supported by the National Institutes of Health (R01AI080275 and R21AI22352), the NIH Fogarty International Center (R25TW009345), the University of Minnesota Center for Translational Science Institute (UL1TR000114), Wellcome Trust (086827, 075470, 097377, 101873 & 200208) and MRC Centre for Medical Mycology (N006364/1). The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.Peer reviewedPublisher PD

The Optimization of the Woodlam Furniture Factory with Specific Reference to It’s Electricity Consumption

Woodlam is the leading plywood furniture manufacturer in South Africa, experiencing steady growth in the last few years. Due to the increasing cost of electricity in South Africa it has become important for companies within the manufacturing industry to find methods to optimize their electricity consumption. This enables these manufacturers to reduce operating costs. Globalization and market pressures also make it necessary to find a means to reduce the cost of production in order to increase profit and remain competitive both locally and internationally. Addressing this problem correctly results in a more profitable business model while allowing production capacity to meet the customer demand. This report includes a literature review to understand key concepts, electricity data collection and analysis, solution research and design of the approach to solving the problem as well as the evaluation and validation of the proposed improvements. This report outlines the importance of finding an effective solution to rising electricity manufacturing costs and depicts the methodology and steps necessary to obtain the desired optimal solution. An indepth study was conducted to provide insight into the manufacturing process. Electricity tariffs and solution approaches were also examined from which an operations research mixed integer linear programming model (MILP) was selected. This model was then formulated to achieve the desired financial benefits that can be achieved through the intelligent scheduling of operations. The monetary and environmental results of the (MILP) model depict that by scheduling the production of the machinery has the ability to assist the production manager to reduce the electricity cost by avoiding peak electricity tariff time periods. The validation process to determine the success of the project is also outlined.Mini Dissertation (B Eng. (Industrial and Systems Engineering))--University of Pretoria, 2017

Evaluation of the two-photon absorption characteristics of GaSb/GaAs quantum rings

The optical parameters describing the sub-bandgap response of GaSb/GaAs quantum rings solar cells have been obtained from photocurrent measurements using a modulated pseudomonochromatic light source in combination with a second, continuous photo-filling source. By controlling the charge state of the quantum rings, the photoemission cross-sections describing the two-photon sub-bandgap transitions could be determined independently. Temperature dependent photo-response measurements also revealed that the barrier for thermal hole emission from the quantum rings is significantly below the quantum ring localisation energy. The temperature dependence of the sub-bandgap photo-response of the solar cell is also described in terms of the photo-and thermal-emission characteristics of the quantum rings. (C) 2014 AIP Publishing LLC

Alimentación, ocio y cultura en el pazo de Goiáns en el siglo XVIII

Actas de la XII Reunión Científica de la Fundación Española de Historia Moderna, celebrada en la Universidad de León en 19-21 de junio de 2012. José Manuel Vázquez Lijó, Universidad de Coruña ([email protected])En esta comunicación se analizan algunos aspectos del micro cosmos cultural de un pazo gallego, el de Goiáns, cuya excepcional ubicación a orillas de la ría de Arousa dota de alto valor añadido a este solar con espacios singulares como pesquera y embarcadero. Los inventarios de bienes de la casa informan de varios indicadores culturales de las elites (libros, juegos, obras artísticas, instrumentos musicales) y otros, como la alimentación, pueden estudiarse gracias a la documentación contable. El breve esplendor material del pazo parece datarse a mediados del siglo XVIII coincidiendo con la exitosa promoción social de los señores de Goiáns y sus hijos consecuencia de un cúmulo de factores (relaciones familiares, poder económico, bodas ventajosas, educación privilegiada…). La carrera militar de los sucesivos dueños les obligó a residir allí donde ejercían estos empleos y Goiáns pasó a ser una segunda residencia, cada vez más vacía de vida y de muebles, convirtiéndose a partir de la década de 1820 en un simple centro de administración de rentas.Peer reviewe