Hydrogen turbine power conversion system assessment

A three part technical study was conducted whereby parametric technical and economic feasibility data were developed on several power conversion systems suitable for the generation of central station electric power through the combustion of hydrogen and the use of the resulting heat energy in turbogenerator equipment. The study assessed potential applications of hydrogen-fueled power conversion systems and identified the three most promising candidates: (1) Ericsson Cycle, (2) gas turbine, and (3) direct steam injection system for fossil fuel as well as nuclear powerplants. A technical and economic evaluation was performed on the three systems from which the direct injection system (fossil fuel only) was selected for a preliminary conceptual design of an integrated hydrogen-fired power conversion system

Predicted Turbine Heat Transfer for a Range of Test Conditions

Comparisons are shown between predictions and experimental data for blade and endwall heat transfer. The comparisons of computational domain parisons are given for both vane and rotor geometries over an extensive range of Reynolds and Mach numbers. Comparisons are made with experimental data from a variety of sources. A number of turbulence models are available for predicting blade surface heat transfer, as well as aerodynamic performance. The results of an investigation to determine the turbulence model which gives the best agreement with experimental data over a wide range of test conditions are presented

Analysing How Users Prefer to Model Contextual Event-Action Behaviours in Their Smartphones

Abstract. Developing context-dependent applications involves indicating the relevant contextual events and the corresponding actions. Based on an analysis of the usability and expressiveness of three Android apps for developing such applications, we have started a study that aims to identify a general solution able to better represent how users classify the relevant concepts in order to facilitate their manipulation during development. We report on a card sorting experiment carried out with 18 users for this purpose, and an analysis of its results, with sug-gestions for improving current designs and informing future solutions

Cytoskeleton structure, pattern of mitochondrial activity and ultrastructure of frozen or vitrified sheep embryos.

Even though sheep embryo cryopreservation is a commonly used procedure the survival and pregnancy outcomes can vary greatly. This study investigated whether cryopreservation was causing subtle changes in ultrastructure, mitochondrial activity or cytoskeletal integrity. Sheep embryos were either slow cooled in 1.5 M EG (n = 22), or vitrified in 20% EG + 20% DMSO with 0.5 M sucrose in Open Pulled Straws (OPS) (n = 24). One hour after warming the cryopreserved embryos differed from control embryos in that they had no mitochondrial activity combined with cytoskeletal disorganization and large vesicles. Vitrified embryos also showed many points of cytoskeleton disruption. Ultrastructural alterations resulting from actin filaments disorganization were observed in both cryopreserved groups. This includes areas presenting no cytoplasmic organelles, Golgi complex located far from the nucleus and a decrease of specialized intercellular junctions. Additionally, large vesicles were observed in vitrified morulae and early blastocysts. The alterations after cryopreservation were proportional to embryo quality as assessed using the stereomicroscope. Even in the absence of mitochondrial activity, grade I and II cryopreserved embryos contained mitochondria with normal ultrastructure. Embryos classified as grade I or II in the stereomicroscope revealed mild ultrastructural alterations, meaning that this tool is efficient to evaluate embryos after cryopreservation

Transport and Photo-Conduction in Carbon Nanotube Fibers

We have characterized the conductivity of carbon nanotubes (CNT) fibers enriched in semiconducting species as a function of temperature and pulsed laser irradiation of 266 nm wavelength. While at high temperatures the response approaches an Arrhenius law behavior, from room temperature down to 4.2 K the response can be framed, quantitatively, within the predictions of the fluctuation induced tunneling which occurs between the inner fibrils (bundles) of the samples and/or the elementary CNTs constituting the fibers. Laser irradiation induces an enhancement of the conductivity, and analysis of the resulting data confirms the (exponential) dependence of the potential barrier upon temperature as expected from the fluctuation induced tunneling model. A thermal map of the experimental configuration consisting of laser-irradiated fibers is also obtained via COMSOL simulations in order to rule out bare heating phenomena as the background of our experiments. (*) AuthorComment: 13 pages and 7 figure

Prolonged magmatism and growth of the Iran-Anatolia Cadomian continental arc segment in Northern Gondwana

Much of the crust of Iran and Anatolia, including their oldest exposed rocks, formed during an episode of intense convergent margin (arc) magmatism as a result of subduction of oceanic lithosphere beneath northern Gondwana from ca 620 Ma to ca 500 Ma, the Cadomian crust-forming event. Most igneous rocks formed between ca 570 and 525 Ma. Cadomian crust is well-known from western and southern Europe and from eastern North America but is much less well-known from Iran and Anatolia. We use published age and compositional data and contribute new data in order to better understand this ancient magmatic system. Cadomian magmatism included calc-alkaline igneous rocks of arc affinity in the main arc and alkalic igneous rocks that formed in a back-arc setting; these igneous rocks are associated with sedimentary rocks. Geochemical and isotopic modelling reveals that basaltic magmas were the main input, that these formed by partial melting in the upper mantle, and that basaltic magmas evolved further in deep crustal hot zones to form granitic magmas through a combination of assimilating older continental crust and fractional crystalization of basaltic magmas.This study was funded by the “ National Key Research and Development Program of China ( 2016YFE0203000 )” and by “ Chinese Academy of Sciences , President's International Fellowship Initiative (PIFI, 2019VCB0013 ). Financial support was also received from the Alexander von Humboldt Foundation in the form of a senior research grant and GEOMAR Helmholtz Centre while preparing these results for publication. FL gratefully acknowledges the PRIN2017 Project 20177BX42Z_001 (Intraplate deformation, magmatism and topographic evolution of a diffuse collisional belt: Insights into the geodynamics of the Arabia-Eurasia collisional zones) and the grant to Department of Science, Roma Tre University (MIUR-Italy Dipartimenti di Eccellenza, ARTICOLO 1, COMMI 314 – 337 LEGGE 232/2016 ). We thank Semih Gürsu for providing us bulk rock data from Derik complex of Turkey. Zircon U–Pb geochronology and and Lu–Hf isotope data were obtained using instrumentation funded by DEST Systemic Infrastructure Grants, ARC LIEF, NCRIS/AuScope, industry partners, and Macquarie University. All logistical support for field studies came from Damghan University. This is contribution 1544 from the ARC Centre of Excellence for Core to Crust Fluid Systems ( http://www.ccfs.mq.edu.au ) and 1412 in the GEMOC Key Centre ( http://www.gemoc.mq.edu.au ), and 1380 from UTD Geosciences and is related to IGCP-662. from the ARC Centre of Excellence for Core to Crust Fluid Systems ( http://www.ccfs.mq.edu.au ), xxxx from the GEMOC Key Centre ( http://www.gemoc.mq.edu.au ), and xxxx from UTD Geosciences and is related to IGCP-662

Comparison of experimentally measured and computational fluid dynamic predicted deposition and deposition uniformity of monodisperse solid particles in the Vitrocell® AMES 48 air-liquid-interface in-vitro exposure system

Accurately determining the delivered dose is critical to understanding biological response due to cell exposure to chemical constituents in aerosols. Deposition efficiency and uniformity of deposition was measured experimentally using monodisperse solid fluorescent particles with mass median aerodynamic diameters (MMAD) of 0.51, 1.1, 2.2 and 3.3 μm in the Vitrocell® AMES 48 air-liquid-interface (ALI) in vitro exposure system. Experimental results were compared with computational fluid dynamic, (CFD; using both Lagrangian and Eulerian approaches) predicted deposition efficiency and uniformity for a single row (N = 6) of petri dishes in the Vitrocell® AMES 48 system. The average experimentally measured deposition efficiency ranged from 0.007% to 0.43% for 0.51–3.3 μm MMAD particles, respectively. There was good agreement between average experimentally measured and the CFD predicted particle deposition efficiency, regardless of approach. Experimentally measured and CFD predicted average uniformity of deposition was greater than 45% of the mean for all particle diameters. During this work a new design was introduced by the manufacturer and evaluated using Lagragian CFD. Lagragian CFD predictions showed better uniformity of deposition, but reduced deposition efficiency with the new design. Deposition efficiency and variability in particle deposition across petri dishes for solid particles should be considered when designing exposure regimens using the Vitrocell® AMES 48 ALI in vitro exposure system