Middle Ordovician Upwelling-Related Ironstone of North Wales: Coated Grains, Ocean Chemistry, and Biological Evolution

Middle Ordovician phosphatic ironstone of the Welsh Basin provides new insight into the paleoenvironmental significance of ironstone and Ordovician ocean chemistry. Deposition occurred in a back-arc basin along the southern margin of Avalonia as the Rheic Ocean opened to the south. Ironstone is interpreted to have accumulated as part of an aggradational parasequence on a storm-dominated shelf with coastal upwelling. This parasequence has a laminated pyritic mudstone base that grades upward into variably bioturbated mudstone and coated grain-rich, intraclastic ironstone, which is overlain in turn by cross-stratified grainstone composed entirely of coated Fe grains. A coarser clastic parasequence composed of more proximal lithofacies rests conformably above and suggests the contact between the two parasequences is a maximum flooding surface marking the onset of highstand conditions. Lithofacies associations suggest that sustained coastal upwelling created a wedge of nutrient-rich, ferruginous seawater on the middle shelf that stimulated high surface ocean productivities. Large, coated Fe grains (granule size) composed of discontinuous and concentric carbonate fluorapatite, hematite, and chamosite cortical layers record fluctuations in pore water Eh that are interpreted to have been related to changes in upwelling intensity and intermittent storm reworking of the seafloor. Results support an emerging model for Ordovician ironstone underpinned by the development of ferruginous bottom water that was periodically tapped by coastal upwelling. Expanding, semi-restricted seaways such as the Rheic Ocean were ideal locations for the ponding of this anoxic, hydrothermally enriched seawater, especially during the early Paleozoic when the deep ocean was variably and inconsistently oxygenated. The coincidence of ironstone depositional episodes with graptolite diversification events suggests that, in addition to Fe, the sustained supply of upwelling-related P may have driven the radiation of some planktonic ecosystems during the Great Ordovician Biodiversification Event. Concomitant minor extinctions of benthic trilobites occurred as these ferruginous waters impinged on the shelf

Hydrocarbon Formation in Immature Sediments

Immature sediments (Ro=<0.6) and hydrates commonly contain low concentrations of C2-8+ alkanes/alkenes, higher alkanes, cycloalkanes and aromatics (temperature=<373 K; Pressure=<100 MPa). Their origin is enigmatic. Traditionally they are interpreted as migrated thermogenic oil. Water treatment experiments have established that they could be formed through the interaction of water and organic carbon by Fe catalysis at 298 K. This study investigates the Eh and pH associated with low temperature (263-298 K) hydrocarbon formation in saline pore-waters containing Ca-montmorillonite and Fe0 (ZVI) over a 300 day period in order to identify the principal reaction mechanisms. The interaction of flowing gaseous carbon dioxide-hydrocarbon mixtures with halite promoted with FexOy, Fex[OH]y at 288 – 308 K is examined experimentally. The study established that halite and mixtures of halite with organic material, Fe-montmorillonite, CaCO3, Ca(OH)2, MgSO4, (NH4)2SO4, K2SO4, pyroclastics, ash, phosphate enriched organic material, and coal can facilitate the removal of CO2, the formation of H2O on the catalyst surface, and the formation of hydrocarbons incorporating the CO2.Key Word: ZVI; Oil formation; CO2; Eh; pH; NaCl; Halite; Montmorillonit

Efeito do extrato aquoso de leucena na germinação e no desenvolvimento do milho.

Foram desenvolvidos bioensaios, na Embrapa-Centro Nacional de Pesquisa de Milho e Sorgo (CNPMS), para avaliar o efeito de extratos aquosos, a frio e a quente, da parte aerea de leucena (Leucaena leucocephala (Lam.) De Wit.), sobre a germinacao e o desenvolvimento das plantas de milho (Ze mays L.). Os extratos foram preparados na concentracao 20% (p/v), e avaliados em solo e papel-germiteste, em casa de vegetacao, e em, papel-filtro em laboratorio. O extrato obtido com agua fria (EF) e aplicado ao solo nao causou nenhum efeito fitotoxico sobre a germinacao e o desenvolvimento das plantas de milho. O extrato obtido com agua quente (EQ), quando aplicado em papel-germiteste ou papel-filtro, causou reducao no comprimento da raiz seminal, mas nao interferiu na germinacao das sementes de milho. O comprimento da raiz seminal foi um indicador mais sensivel aos efeitos do EQ do que a germinacao

Interview with Harry Pahukoa, Jr.

A man who grew up in Keanae tells of his parents' background, his schooling, and army tour of duty. He describes the 1946 tidal wave which took the life of his aunt. The escape of his mother and her grandchildren, death of his aunt, Young Men's Christian Association and Red Cross assistance, and current precautions are among the topics discussed.soldier; Hawaiian-Chinese-Tahitian; maleInterview conducted in English.State, Federal, Privat

Determination of Surfactant Solution Viscosities with a Rotational Viscometer

Aqueous surfactant solutions are used in engineering systems for improving boiling heat transfer. The purpose of this research is to determine the viscosities of surfactant solutions and to investigate the effect of composition on viscosity. The results obtained can possibly be used as reference for further study in the effects of surfactant solution viscosities on nucleate boiling. A rotational viscometer was used to determine the viscosities of three surfactant solutions – SLS, EH-14, and SA-9 – of various compositions at room temperature. It was discovered that the viscosities of SLS, EH-14, and SA-9 had a nearly consistent pattern as their compositions increased. The approximate maximum viscosity measured was 1.39 mPa.s for SLS, 1.52 mPa.s for EH-14, and 3.17 mPa.s for SA-9. Based on the results, it was inferred that as the composition of these surfactant increases, so does the viscosity of the solution

Gap Analysis of Environmental Health Research in Malawi : Report to the National Commission of Science and Technology

The aim of this consultancy was to assess the current gaps in research for the environmental health sector in Malawi, and to recommend research priorities and an effective action plan to address these gap

Application of Photo-Electrochemically Generated Hydrogen with Fuel Cell Based Micro-Combined Heat and Power: A Dynamic System Modelling Study

Photo-electrochemical (PEC) hydrogen generation is a promising technology and alternative to photovoltaic (PV)-electrolyser combined systems. Since there are no commercially available PEC cells and very limited field trials, a computer simulation was used to assess the efficacy of the approach for different domestic applications. Three mathematical models were used to obtain a view on how PEC generated hydrogen is able to cover demands for a representative dwelling. The analysed home was grid-connected and used a fuel cell based micro-CHP (micro-combined heat and power) system. Case studies were carried out that considered four different photo-electrode technologies to capture a range of current and possible future device efficiencies. The aim for this paper was to evaluate the system performance such as efficiency, fuel consumption and CO2 reduction capability. At the device unit level, the focus was on photo-electrode technological aspects, such as the effect of band-gap energy represented by different photo-materials on productivity of hydrogen and its uncertainty caused by the incident photon-to-current conversion efficiency (IPCE), which is highly electrode preparation specific. The presented dynamic model allows analysis of the performance of a renewable energy source integrated household with variable loads, which will aid system design and decision-making

Antimicrobial and antioxidant potentials, total phenolic contents of some herbal waters

The aim of the actual study is to evaluate antimicrobial and antioxidant potentials, total phenolic contents of thyme (Thymus sp.), myrtle (Myrtus communis L.), eucalyptus (Eucalyptus globulus L.) and rosemary herbal waters (Rosmarinus officinalis L.). They were bought a retailer in Giresun. In the studies, it was determined that only thyme water exhibited antimicrobial activity in all herbal waters. Streptomycine, tetracycline and nystatin which were synthetic antimicrobials demonstrated higher activity than studied herbal waters. Moreover; total flavonoid contents of the tested waters ranges from 50.19±0.0038 µL CE/mL to 126.15±0.004 µL CE/mL. The highest and the lowest total phenolic contents were detected in the thyme water and the eucalyptus water as 688.18±0.009 µL GAE/mL and 24.54±0.0008 µL GAE/mL, respectively. DPPH and ABTS radical scavenging activities of the herbal waters exhibited a dose dependent manner and increased with increasing conentrations. As a result of this study, it was concluded that thyme water could be an alternative to synthetic antimicrobial agents and thyme water, myrtle water, eucalyptus water and rosemary waters might be an alternative to synthetic antioxidative agents. Hence, further and detailed investigations are needed to determine active constituents in the herbal waters. DOI: http://dx.doi.org/10.5281/zenodo.450154