Drained cyclic behaviour of loose Dogs Bay sand

The results of drained cyclic triaxial tests performed on Dogs Bay sand (a carbonate sand) are discussed in this paper. For this sand it has been previously demonstrated that the critical state exists and is unique. The relationship between volumetric strains due to cyclic loading and the critical state of this material under monotonic conditions is explored here. Drained cyclic tests on loose samples have been carried out, applying different amplitudes of cyclic loading for samples that generally have initial states on the wet side of critical. The trends of behaviour are summarised, pointing out the relationship between initial state parameter, amplitude of cyclic loading and final change in the state parameter at equilibrium. Experimental evidence is also given to demonstrate that the sand has a memory of the volumetric strain that has previously occurred when different patterns of cyclic loading are consecutively applied and equilibrium has not been reached

Effect of Class F Fly Ash on Fine Sand Compaction through Soil Stabilization

This paper presents the results of an experimental investigation carried out to evaluate the effect of fly ash (FA) on fine sand compaction and its suitability as a material for embankments. The literature review demonstrates the lack of research on stabilization of sandy material using FA. The study is concerned with the role of FA content in stabilized soil physical characteristics. The main aim of this paper is to determine the optimum quantity of FA content for stabilization of this type of soil. This is achieved through particle size distribution and compaction (standard proctor) tests. The sand was stabilized with three proportions of FA (5%, 10% and 15%) and constant cement content of 3% was used as an activator. For better comparison, the sand was also stabilized by 3% cement only so that the effect of FA could be observed more clearly. The results were in line with the literature for other types of soil, i.e. as the % of FA increases, reduction in maximum dry density and higher optimum moisture content were observed

Performance of heterogeneous earthfill dams under earthquakes: optimal location of the impervious core

Earthfill dams are man-made geostructures which may be especially damaged by seismic loadings, because the soil skeleton they are made of suffers remarkable modifications in its mechanical properties, as well as changes of pore water pressure and flow of this water inside their pores, when subjected to vibrations. The most extreme situation is the dam failure due to soil liquefaction. Coupled finite element numerical codes are a useful tool to assess the safety of these dams. In this paper the application of a fully coupled numerical model, previously developed and validated by the authors, to a set of theoretical cross sections of earthfill dams with impervious core, is presented. All these dams are same height and have the same volume of impervious material at the core. The influence of the core location inside the dam on its response against seismic loading is numerically explored. The dams are designed as strictly stable under static loads. As a result of this research, a design recommendation on the location of the impervious core is obtained for this type of earth dams, on the basis of the criteria of minor liquefaction risk, minor soil degradation during the earthquake and minor crest settlement

Element behaviour during combustion in coal-fired Orhaneli power plant, Bursa-Turkey

This study focuses on element behaviour during combustion in the Orhaneli thermal power plant (a 210 MW unit, Bursa-Turkey). A total of 51 samples, feed coals (FCs), fly ashes (FAs) and bottom ashes (BAs), which were systematically collected over an eight-week period, have been analysed for major, minor and trace elements (Al, Ca, Fe, K, Mg, Na, S, As, B, Ba, Be, Bi, Cd, Co, Cr, Cs, Cu, Ga, Ge, Hf, Hg, Li, Mn, Mo, Nb, Ni, P, Pb, Rb, Sb, Sc, Se, Sn, Sr, Ta, Th, Ti, Tl, U, V, W, Y, Zn, Zr and REEs). This study shows that FCs on an airdried basis have high moisture (av. 9%), high volatile matter (av. 33%), very high ash yield (av. 53%), relatively high sulfur content (av. 2.14%) and low gross calorific value (av. 1775 kcal/kg). Proximate analyses of combustion residues imply that BAs have higher contents of unburned carbonaceous matter than FAs. Mean values of trace element concentrations in FCs fall within the ranges of most world coals, except for Cr, Cs, Ni and U which occur in concentrations slightly higher than those determined for most of world coals. Some elements such as S, Hg, As, B, Bi, Cd, Cs, Ge, K, Pb, Rb, Sb, Se, Sn, Tl, and Zn are indicating enrichments in FAs. The remaining elements investigated in this study have no clear segregation between FAs and BAs. The mass balance calculations point to Ca content of feed coal controlling the partitioning of elements in this power plant, producing a high removal efficiency for highly volatile elements such as Hg, B and Se, and a high retention of As, Bi, Cd, Cs, Ge, Pb, Rb, Sb, Sn, Tl and Zn in FAs. However, the high enrichment in trace elements of FAs can increase the hazardous potential of this coal by-product

Efficient Scalable Computing through Flexible Applications and Adaptive Workloads

In this paper we introduce a methodology for dynamic job reconfiguration driven by the programming model runtime in collaboration with the global resource manager. We improve the system throughput by exploiting malleability techniques (in terms of number of MPI ranks) through the reallocation of resources assigned to a job during its execution. In our proposal, the OmpSs runtime reconfigures the number of MPI ranks during the execution of an application in cooperation with the Slurm workload manager. In addition, we take advantage of OmpSs offload semantics to allow application developers deal with data redistribution. By combining these elements a job is able to expand itself in order to exploit idle nodes or be shrunk if other queued jobs could be initiated. This novel approach adapts the system workload in order to increase the throughput as well as make a smarter use of the underlying resources. Our experiments demonstrate that this approach can reduce the total execution time of a practical workload by more than 40% while reducing the amount of resources by 30%.This work is supported by the Project TIN2014-53495-R and TIN2015-65316-P from MINECO and FEDER. Antonio J. Peña is cofinanced by MINECO under Juan de la Cierva fellowship number IJCI-2015-23266. Special thanks to José I. Aliaga for the conjugate gradient code.Peer ReviewedPostprint (author's final draft

Cord blood Lin(-)CD45(-) embryonic-like stem cells are a heterogeneous population that lack self-renewal capacity.

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Human umbilical cord blood (hUCB) has been proposed to contain not only haematopoietic stem cells, but also a rare pluripotent embryonic-like stem cell (ELSc) population that is negative for hematopoietic markers (Lin(-)CD45(-)) and expresses markers typical of pluripotent cells. The aim of this work was to isolate, characterise and expand this ELSc fraction from hUCB, as it may provide a valuable cell source for regenerative medicine applications. We found that we could indeed isolate a Lin(-)CD45(-) population of small cells (3-10 µm diameter) with a high nucleus to cytoplasm ratio that expressed the stem cell markers CD34 and CXCR4. However, in contrast to some previous reports, this fraction was not positive for CD133. Furthermore, although these cells expressed transcripts typical of pluripotent cells, such as SOX2, OCT3/4, and NANOG, they were not able to proliferate in any of the culture media known to support stem cell growth that we tested. Further analysis of the Lin(-)CD45(-) population by flow cytometry showed the presence of a Lin(-)CD45(-)Nestin(+) population that were also positive for CD34 (20%) but negative for CXCR4. These data suggest that the Lin(-)CD45(-) stem cell fraction present in the cord blood represents a small heterogeneous population with phenotypic characteristics of stem cells, including a Lin(-)CD45(-)Nestin(+) population not previously described. This study also suggests that heterogeneity within the Lin(-)CD45(-) cell fraction is the likely explanation for differences in the hUCB cell populations described by different groups that were isolated using different methods. These populations have been widely called "embryonic-like stem cell" on the basis of their phenotypical similarity to embryonic stem cells. However, the fact they do not seem to be able to self-renew casts some doubt on their identity, and warns against defining them as "embryonic-like stem cell" at this stage.Anthony Nolan and the Great Ormond Street Hospital Charity for financial support. Cesar Alvarez-Gonzalez is a fellowship from Consejo Nacional de Ciencia y Tecnologia (CONACyT) and Instituto Jaliscience de la Juventud (IJJ); Mexico

Partitioning of trace elements in a entrained flow IGCC plant: Influence of selected operational conditions

The partitioning of trace elements and the influence of the feed conditions (50:50 coal/pet-coke feed blend and limestone addition) was investigated in this study. To this end feed fuel, fly ash and slag samples were collected under different operational conditions at the 335 MW Puertollano IGCC power plant (Spain) and subsequently analysed. The partitioning of elements in this IGCC plant may be summarised as follows: (a) high volatile elements (70–>99% in gas phase): Hg, Br, I, Cl and S; (b) moderately volatile elements (up to 40% in gas phase and 60% in fly ash): As, Sb, Se, B, F, Cd, Tl, Zn and Sn; (c) elements with high condensation potential: (>90% in fly ash): Pb, Ge, Ga and Bi; (d) elements enriched similarly in fly ash and slag 30–60% in fly ash: Cu, W, (P), Mo, Ni and Na; and (e) low volatile elements (>70% in slag): Cs, Rb, Co, K, Cr, V, Nb, Be, Hf, Ta, Fe, U, Ti, Al, Si, Y, Sr, Th, Zr, Mg, Ba, Mn, REEs, Ca and Li. The volatility of As, Sb, and Tl and the slagging of S, B, Cl, Cd and low volatile elements are highly influenced by the fuel geochemistry and limestone dosages, respectively

Dissemination and survival of commercial wine yeast in the vineyard: a large-scale, three years study

The use of commercial wine yeast strains as starters has been extensively generalised over the past two decades. In this study, a large-scale sampling plan was devised over a period of three years in six different vineyards to evaluate the dynamics and survival of industrial yeast strains in the vineyard. A total of 198 grape samples were collected at various distances from the wineries, before and after harvest, and yeast strains isolated after spontaneous fermentation were subsequently identified by molecular methods. Among 3780 yeast strains identified, 296 isolates had a genetic profile identical to that of commercial yeast strains. For a large majority (94%), these strains were recovered at very close proximity to the winery (10-200m). Commercial strains were mostly found in the post harvest samples, reflecting immediate dissemination. Analysis of population variations from year to year indicated that permanent implantation of commercial strains in the vineyard did not occur, but instead that these strains were subject to natural fluctuations of periodical appearance/disappearance like autochthonous strains. Our data show that dissemination of commercial yeast in the vineyard is restricted to short distances and limited periods of times and is largely favoured by the presence of water runoff.ENOSAFE (Nº 762, Programa AGRO, medida 8.1) and the grant nº 657 C2 from the cooperation agreement between the Portuguese Institute for International Scientific and Technological Cooperation (ICCTI) and the French Embassy in Lisbon and the Marie Curie Fellowship of the European Community programme of Quality of Life under Contract QLK4-CT-2001-51873