Large bodies of keratophyric tuffs and keratophyric flows from Harrison Mills, British Colombia are described structurally and petrologically. The origin of the albitic feldspar in these rocks is discussed and concluded to be primary. Petrological comparisons are made between the tuffs and the flows. Both types of rocks were artificially fused to glasses, and the refractive indices of these glasses are compared. From these studies the tuffs and the lavas are concluded to be consanguineous. The keratophyric flows were analysed chemically and found similar to keratophyric rocks from other localities. The origin of the lavas is discussed. It is concluded that these rocks were probably formed by differentiation of a trondjhemitic magma possibly contaminated by soda rich sediments. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Contained within is a sample, consisting of the first twelve chapters, which portray the final days of the fictional Polian War. The events are a springboard for the rest of the novel, and indeed the series.

The fly ash from secondary lead metallurgy was placed in two different soils in order to investigate the kinetics of release (in a time horizon of 504 h) and mobility of metals/metalloids in soil water and soil. Uncontaminated soils used for the pot experiment were two: acidified forest soil N and agricultural soil H. An experimental bag containing 0.5 g of fly ash was placed in a pot with 200 g of soil, which was watered using deionised water at the 60 % water holding capacity (WHC) level. Using Rhizon pore water samplers the soil solution was regularly sampled and subsequently analysed. The soil solution analysis was supplemented by the geochemical speciation-solubility modelling using the PHREEQC-2 code and the mineralogical investigation of solid phase. For Cd, Zn and As the release in soil water had similar behaviour in time: during first 96 hours of the experiment their concentration increased up to maximum values and then slowly decreased till the end of experiment. This trend has not been observed for Cu, Pb and Sb, being tightly bound to secondary phases newly formed directly in the fly ash or to soil constituents, or indicating possible resistance to leaching. Weight loss after the experiment for the fly ash was in both soils approximately 60 %, indicating high level of its dissolution....

Bibliography: pages 161-166. / The chemical and mineral compositions are presented for 63 pulverized fuel ash (PFA) and 16 input coal samples collected from Lethabo, Duvha and Matla power stations over the period 1987-1988. Bulk chemical composition was determined by X-ray fluorescence spectrometry. The mineral concentrations were determined by semi-quantitative X-ray diffraction based on integrated counts over peak areas, with silicon used as an internal standard. The particle size distributions were determined for two sample sets from each power station with a Malvern Instruments Particle Sizer. The major phases present in the ash are glass ( 45-75% ), mullite (16-39%) and quartz (1.5-16% ). The quartz concentration decreases in PF A from fields 1 to 4 in all the stations, and is positively correlated with the SiO₂ concentration. The concentrations of glass, mullite and quartz in PFA generally vary within well defined limits which remain constant with time. An exception is the glass concentration in Duvha PFA. Spinel concentration generally decreases in concentration in PFA from fields 1 to 4, and is positively correlated with the Fe₂O₃ concentration. Of the trace elements determined, Zr, Rb and Mn generally have no or very low enrichment in concentration in PFA from fields 1 to 4. The highest enrichment factors ( > 5) were found for As, Ge and Se in Duvha PF A. The composition of the glass and ferrite spinel phases were determined by electron microprobe analysis. The glass consists of SiO₂ (21-100%) and Al₂ O₃ (0.1-49%), with significant proportions of CaO, TiO₂, Fe₂O₃ and MgO. Al₂O₃ , MgO and TiO₂ substitute for FeO in the spinel structure, with MgO substitution dominant in Duvha spinels. Chemical mass balance calculations suggest that of the elements determined for Lethabo PFA, the only one released in a significant proportion to the atmosphere is S(92% ).

The study being undertaken was to ascertain the effect or effects of different firing conditions and colorants on glazes composed of wood ash from two trees indigenous to Texas. The problem was divided into two parts: first, to identify the best mixtures using the selected vegetable ash; second, to alter successful glazes with set percentages of colorants. The main objective of the study was to evaluate findings resulting from the variation of elements, firing conditions, and colorants used and to select successful glazes.

No description available.

No description available.

European ash trees (Fraxinus excelsior ) are under threat from the fungal pathogen Hy- menoscyphus fraxineus causing ash dieback disease (ADB). Previous research has shown heritable variation in ADB susceptibility in natural ash populations. Prior to this project, very little genetic data were available for ash, thus hampering efforts to identify markers associated with susceptibility. In this thesis, I have presented nuclear and organellar assemblies of the 880 Mbp F. excelsior genome, with a combined N50 scaffold size of over 100 kbp. Using Ks distributions for six plant species, I found evidence for two whole genome duplication (WGD) events in the history of the ash lineage, one potentially shared with olive (Ks 0.4), and one potentially with other members of the Lamiales order (Ks 0.7). Using a further 38 genome sequences from trees originating throughout Europe, I found little evidence of any population structure throughout the European range of F.excelsior, but nd a substantial decrease in effective population size, both in the distant (from 10 mya) and recent past. Linkage disequilibrium is low at small distances between loci, with an r2 of 0.15 at a few hundred bp, but decays slowly from this point. From whole genome DNA methylation data of twenty F. excelsior and F. mandshurica trees, I identi ed 665 Differ- entially Methylated Regions (DMRs) between those with high and low ADB susceptibility. Of genes putatively duplicated in historical WGD events, an average of 25.9% were differen- tially methylated in at least one cytosine context, possibly indicative of unequal silencing. Finally, I found some variability in methylation patterns among clonal replicates (Pearson's correlation coefficient 0.960), but this was less than the variability found between different genotypes ( 0.955). The results from this project and the genome sequence especially, will be valuable to researchers aiming to breed or select ash trees with low susceptibility to ADB.

Thesis (M.S.)--Oregon State University, 1985. / One map folded in pocket. Typescript (photocopy). Includes bibliographical references (leaves 85-90). Also available online.

Fly ash is a waste product from thermal power plants where pulverised coal is used for the generation of electricity. Fly ash is being utilised in the blended cements, additive for concrete and manufacturing of concrete blocks and bricks. Fly ash-lime-gypsum bricks are being manufactured and marketed throughout the country. The literature review on fly ash-lime-gypsum (FALG) mixtures as intended to manufacture bricks or blocks for masonry applications indicates several gaps in understanding the various aspects of the technology. The present thesis is an attempt to understand the behaviour of compacted stabilised fly ash mixtures for the manufacture of fly ash bricks and characteristics of masonry using such bricks. A brief introduction to the technology of compacted stabilised fly ash bricks for structural masonry is provided. Review of the literature on fly ash-lime and fly ash-lime-gypsum mixtures, and fly ash bricks is provided in chapter 1. Chapter 2 gives details of the experimental programme, properties of raw materials used in the experimental investigations, methods of preparing different types of specimens and their testing procedures. Chapter 3 deals with the strength and absorption characteristics of compacted stabilised fly ash mixtures in greater detail. The main focus of the investigations is on arriving at the optimum stabilizer-fly ash mixtures considering density, stabilizer-fly ash ratio, curing conditions, etc. as the variables. Therefore the parameters/variables considered in the investigation include: (a) density of the compacted fly ash mixture, (b) stabilizer-fly ash ratio, (c) curing duration (normal curing and steam curing) and (d) dosage of additives like gypsum. Some of the major conclusions of the investigations are (a) compressive strength of compacted stabilised fly ash mixtures is sensitive to dry density of the specimens and the strength increases with increase in density irrespective of stabiliser content and type of curing, (b) Optimum limefly ash ratio yielding maximum strength is 0.75, (c) addition of gypsum accelerates rate of strength gain for compacted fly ash-lime mixtures (d) for 28 days wet burlap curing optimum gypsum content yielding maximum strength is 2% and maximum compressive strength is achieved for lime contents in the range of 10 – 17%, (e) steam curing (at 80 °C for 24 hours) gives highest compressive strength for compacted fly ash-lime mixtures. Characteristics of compacted fly ash-lime, fly ash-lime-gypsum and fly ash-cement bricks and their masonry are presented in chapter 4. Compressive strength, elastic modulus, water absorption, initial rate of absorption, dimensional stability and durability of the bricks were examined. Compressive strength, flexure bond strength and stress strain relationship for the fly ash brick masonry using cement-lime mortar were evaluated. The investigations clearly show the possibility of producing bricks of good quality using compacted fly ash-lime gypsum mixtures. Wet compressive strengths of 8- 10 MPa was obtained for compacted fly ash-lime-gypsum bricks at the age of 28 days. Wet strength to dry strength ratio for these bricks is in the range of 0.55 – 0.67. Initial tangent modulus for the fly ash-lime-gypsum bricks in saturated condition is in the range of 8000 – 12000 MPa. There is a large scope for selecting optimum mix ratios of fly ash, sand, lime and other additives to obtain a specific designed strength for the brick. The thesis ends with Chapter 5 highlighting major conclusions of the investigations.