2 ABSTRACT: Following the identification of grey quartz–albite–chlorite–calcite–muscovite rocks in Meso- to Neo-proterozoic sequences in Scotland as metamorphosed tuffs of intermediate composition, it has been shown that this lithology will generate calc-silicate rocks at higher metamorphic grades. Both rock types occur as thin beds with sharp contacts with their host, occur as multiple beds in isolated suites, and share chemical compositions suggestive of volcanic sources with tholeiitic andesite affinities. The failure to recognise calc- silicate rocks as tuffs might explain the apparent scarcity of volcanogenic material through c. 220 million years of early Earth history in Scotland.
34 Read more
Although the determination of absolute concentrations for some REE isotopes depend crucially on the reliability of the correction factors, the impact of any inadequate corrections on petrological considerations would depend on the ap- pearance of the trends in chondrite normalised plots, in particular on the pres- ence of positive or negative Eu anomalies. Thus Figure 8 shows the trends for the three rocks separately with each panel showing the data trends for 2017 (6717), 2018 (6918) with corrected REE data, and 2018 (6918) data with uncor- rected REE values. Figure 8(A) (R.19) shows excellent agreement for the cor- rected data for both the main data sets for R.19 without a significant Eu anoma- ly. However, the data points for uncorrected Eu and Gd are both displaced to higher values and indeed the Eu in this rock shows an apparent small positive Eu anomaly. The uncorrected points for the heavier REE all overplot the corrected points. Figure 8(B) shows good agreement for the two main data sets for R.26 and that the uncorrected data points for Eu and Gd both plot only slightly above their corrected values. Figure 8(C) for R.226 shows clearly that, except for Ce, the 2018 analyses are consistently displaced upwards from the values for the 2017 analyses. However, the overall appearance is the same with clear negative Eu anomalies and a clear positive anomaly for Ce, particularly for the 2017 data set. Note also that the uncorrected point for Eu overlies the corrected point for the 2018 data which reflects the very low Ba content in this rock while the un- corrected 2018 point for Gd is displaced to higher values from the corrected point reflecting the effect of the high Ce content (as 140 CeOH) on the determina-
44 Read more
Selection for new cereal varieties with increased performance (e.g., uptake and accumulation of silica) in response to silicate rock/agro-mineral fertilization could be achieved through conventional breeding and/or using gene editing techniques to modify elite varieties (e.g., CRISPR-Cas9). Engineering crop varieties that are effectively able to exploit soil amended with crushed silicate rocks would potentially deliver significant benefits by improving nutrient supply to fertilize production and increasing protection against pests and diseases as well as promoting weathering to raise pH, cation exchange capacity and increase soil organic carbon capture. However, such potential benefits require demonstration in replicated field trials (Table 1).
22 Read more
Highly weathered soils in areas from Brazil are acidic soils, typically characterized by poor fertili- ty, particularly with low soil phosphorus level. This laboratory experiment was carried out to evaluate the influences of biochar, made from the poultry litter and MB-4, rock dust from grinding of silicate rocks in increasing the available soil phosphorus on Ultisol, Oxisol and Entisol. Thus, one experiment involving soils incubation was conducted in laboratory, during 100 days. The treatments consisted of rock powder, MB-4 and poultry litter, biochar, evaluated by the base sa- turation method, with correction levels from 40% to 80% for Ultisol and Entisol and from 20% to 80% for Oxisol and three replicates. After the incubation period, the soil samples were analyzed in relation to available phosphorus in the soil. The results of this study confirmed that the biochar prepared from the poultry litter through slow pyrolysis was a potential source of phosphorus, particularly to weathered soils. Biochar released phosphorus into the soils. The biochar could be used in the improvement of available phosphorus for the three soils analyzed. During the incuba- tion period, 100 days, the application of increasing doses of MB-4 in soils there was no improvement in the available soil phosphorus. MB-4 was not a source of phosphorus to the soil in a short term.
ratios for ultramafic and mafic silicate rocks in dykes and pipes range up to 5, indicating a very small degree of melting of a carbonated mantle at depth. Damkjernites appear to be transitional to carbonatites. Trace element modelling indicates that all the mafic silicate magmas are related to small degrees of melting of a metasomatised garnet peridotite source. Similarities of the REE patterns and initial Sr and Nd isotope compositions for ultramafic alkaline silicate rocks and carbonatites indicate that there is a strong relationship between the two magma-types. There is also a strong petrogenetic link between carbonatites, kimberlites and alkaline ultramafic lamprophyres. Fractional crystallisation of olivine, diopside, melilite and nepheline gave rise to the evolved nepheline syenites, and formed the ultramafic cumulates. All magmas in the KACP appear to have originated in a single event, possibly triggered by the arrival of hot material (mantle plume?) beneath the Archaean/Proterozoic lithosphere of the northern Baltic Shield that had been recently metasomatised. Melting of the carbonated garnet peridotite mantle formed a spectrum of magmas including carbonatite, damkjernite, melilitite, melanephelinite and ultramafic lamprophyre. Pockets of phlogopite metasomatised lithospheric mantle also melted to form potassic magmas including kimberlite. Depth of melting, degree of melting and presence of metasomatic phases are probably the major factors controlling the precise composition of the primary melts formed.
22 Read more
concentrations and high 87 Sr/ 86 Sr ratios and thus have a ma- jor influence on the increase in the Sr isotopic composition of seawater (e.g., Krishnaswami et al., 1992; Harris, 1995; Derry and France-Lanord, 1996; Quade et al., 1997; Singh et al., 1998, 2006; Galy et al., 1999; English et al., 2000; Dalai et al., 2003). Therefore, many researchers attribute the steady increase in the 87 Sr/ 86 Sr ratio in the oceans since the Ceno- zoic mainly to the uplifting of the Qinghai–Tibet Plateau, which caused increased silicate weathering and highly ra- diogenic Sr flux to the oceans. As the silicate rocks in the southern Himalayas have both high 87 Sr/ 86 Sr ratios and high Sr concentrations, the rise of the Sr isotopic composition of seawater since the Cenozoic can be used as a proxy of in- tensified silicate weathering (Palmer and Elderfield, 1985; Raymo et al., 1988; Edmond, 1992; Krishnaswami et al., 1992; Richter et al., 1992; Harris, 1995; Blum, 1997; Galy et al., 1999; Chesley et al., 2000; English et al., 2000; Bickle et al., 2005). However, other studies have shown that the un- usual metamorphic evolution of the Himalayas was enriched with carbonates, resulting in abnormally high 87 Sr/ 86 Sr ra- tios, and that the weathering of such carbonates might con- trol the 87 Sr/ 86 Sr ratios of river water (e.g., Edmond, 1992; Palmer and Edmond, 1992; Quade et al., 1997; Blum et al., 1998; Harris et al., 1998; English et al., 2000; Karim and Veizer, 2000; Jacobson and Blum, 2000; Bickle et al., 2001; Jacobson et al., 2002a). If much of the radiogenic Sr in the rivers is derived from carbonate weathering, then changes in the seawater Sr isotopic composition would not be a proxy of the continental silicate weathering intensity.
15 Read more
The aim of the present study was to test the hypotheses that (i) ectomycorrhizal weathering is ulti- mately driven by fungal allocation of photoassimilate received from a host plant (in this case, Pinus sylvestris), (ii) the release of calcium from minerals, and its accumulation as a weathering product by a symbiotic fungal partner (in this case, P. involutus), is linked to mineral-specific rates of fungal secretion of oxalic acid and the formation of calcium oxalate. To address these hyphotheses, monoxenic micro- cosms were designed with mineral weathering arenas, containing grains of a range of important car- bonate and silicate rocks and minerals (limestone, basalt, gabbro, granite, olivine, microcline) of various calcium and phosphorus concentrations and a control mineral (quartz, 0.01% CaO, 0.0006% P 2 O 5 ). These
15 Read more
Examination of the reacted fracture fill showed that after 15 years, in both leachate systems, grains were coated with sec- ondary Mg–(Al)–(K)–silicate minerals, most likely a mixture of talc, smectite (Mg–rich saponite–K) and interstratified illite/smectite. Similar Mg-rich solid phases have been observed previously as minor components in high pH clay alteration experiments/ana- logues. For example, saponite was recognised as an alteration product of bentonite by Cuevas (2004), secondary Mg-enriched mineral phases have been observed at the Tournemire analogue site (Tinseau et al., 2006; Techer et al., 2012) and palygorskite was identified as an Mg-rich alteration product of bentonite by high pH groundwaters in the Troodos natural analogue site (Alexander et al., 2012). The formation of these phases at these high pH conditions is not unexpected as they are commonly asso- ciated with alkaline, saline lake environments (Yeniyol, 2007, 2012; Hojati et al., 2010; Akbulut and Kadir, 2003) where they form from post-sedimentary alteration of soils and rocks in high pH fluids in the presence of dolomitic material (Derkowski et al., 2013; Xie et al., 2013; Schwarzenbach et al., 2013; Birsoy, 2002). Their formation has also been identified in cement–aggregate sys- tems where dedolomitisation in the presence of Ca(OH) 2 and
16 Read more
In this paper, the explicit formulas for the reduced hyper-Zagreb index and its polynomial of silicate and chain silicate networks are computed. These expressions can correlate the molecular structure of silicate and chain silicate networks to information about their physical structures.
This dissertation serves to analyze and report upon the use of lanthanide-based high-κ dielectrics for high-end metal-oxide-semiconductor field effect transistor (MOSFET) devices. Lanthanum oxide was studied by electrical and analytical means in the framework of an MOS gate stack. This dielectric was chosen due to its optimal electrical properties and high thermodynamic stability in the silicate phase. The electrical data obtained for such a stack is of unparallel electrical quality under processing temperatures compatible with identified low and high-temperature MOSFET processing routes. Materials characterization provides a detailed analysis as to high-quality of the devices. The first section of this chapter summarizes the innovative and technical accomplishments that have been reported in the dissertation. The final section briefly overviews the future direction of the high-κ dielectric in terms of future transistor design.
192 Read more
Examination of the reacted fracture ﬁll showed that after 15 years, in both leachate systems, grains were coated with sec- ondary Mg–(Al)–(K)–silicate minerals, most likely a mixture of talc, smectite (Mg–rich saponite–K) and interstratiﬁed illite/smectite. Similar Mg-rich solid phases have been observed previously as minor components in high pH clay alteration experiments/ana- logues. For example, saponite was recognised as an alteration product of bentonite by Cuevas (2004), secondary Mg-enriched mineral phases have been observed at the Tournemire analogue site (Tinseau et al., 2006; Techer et al., 2012) and palygorskite was identiﬁed as an Mg-rich alteration product of bentonite by high pH groundwaters in the Troodos natural analogue site (Alexander et al., 2012). The formation of these phases at these high pH conditions is not unexpected as they are commonly asso- ciated with alkaline, saline lake environments (Yeniyol, 2007, 2012; Hojati et al., 2010; Akbulut and Kadir, 2003) where they form from post-sedimentary alteration of soils and rocks in high pH ﬂuids in the presence of dolomitic material (Derkowski et al., 2013; Xie et al., 2013; Schwarzenbach et al., 2013; Birsoy, 2002). Their formation has also been identiﬁed in cement–aggregate sys- tems where dedolomitisation in the presence of Ca(OH) 2 and
15 Read more
An aqueous sodium silicate solution (4.5 mL) and a kerosene solution (40.5 mL) containing TGCR as a surfac- tant were mixed using a homogenizer (MA-2500, Tokushukika Co., Ltd., Japan) at 2500 rpm for 10 min to pro- duce the W/O emulsions. The obtained emulsions (10 mL) were poured into the calcium-loading solution (100 mL) and stirred at 50 rpm. The solid products formed in the emulsions were filtered off, washed with distilled water, and dried. The preparation was performed at room temperature.
stocks including Ca and Mg silicate materials is a possible technology for the reduction of carbon dioxide emission to the atmosphere. 1–3) In particular, mineral carbonations using industrial residues, such as combustion residues, steel slag and waste cement have the advantages of low cost and widespread availability in industrial areas when compared with ores. 4) Among these, steel slag is a very attractive
Basically, plant reactions to attack plant pathogens are very complex, and involve the activation of set of genes, encoding different proteins. Pathogen attack can induce biochemical and physiological changes in plants, such as physical strengthening of the cell wall through lignification, suberization, and callose deposition by producing phenolic compounds, phytoalexins, and pathogenesis-related (PR) proteins which subsequently prevent various pathogen inva- sions (Ebrahim et al. 2011). These processes go generally in parallel to our results herein which indicated that all tested treatments significantly increased the enzyme activities. The highest increase was obtained with potassium silicate and calcium silicate applied as soil treatment + foliar spray which increased the activity of peroxidase, polyphenol oxidase, and chitinase enzymes by 200 and 175, 250 and 233.3, and 225 and 200%, respectively. Other treatments showed moderate effect. In this respect, Ryals et al. (1996) reported that pro- duction and accumulation of pathogenesis-related proteins in plants in response to invading pathogen and/or stress situation is very important. Phytoalexins are mainly produced by healthy cells adjacent to localized damaged and necrotic cells, but PR proteins accumulate locally in the infected and surrounding tissues, and also in remote uninfected tissues. Production of PR proteins in the unin- fected parts of plants can prevent the affected plants from further infection. Most PR proteins in the plant species are acid-soluble, low molecular weight, and protease-resistant proteins. Currently PR proteins include families distin- guished according to their properties and functions such as β -1,3-glucanases, chitinases, thaumatin-like proteins, peroxidases, ribosome-inactivating proteins, defenses, thio- nins, nonspecific lipid transfer proteins, oxalate oxidase, and oxalate-oxidase-like proteins (Ebrahim et al. 2011).
Sodium hydroxide and Sodium silicate are commercially available in market in pellets form. In all forms, sodium hydroxide is highly corrosive and reactive. Sodium hydroxide solution reacts readily with metals such as aluminum, magnesium, zinc, tin, chromium, bronze, brass, copper, and tantalum. . It reacts with most animal tissue, including leather, human skin, and eyes. It also reacts readily with various reducing sugars (i.e., fructose, galactose, maltose, dry whey solids) to produce carbon monoxide.
cate units which are enriched with NBO atoms The major modifiers are con- sumed to form NBO in silicate network and the few are aggregated to form crystalline silicate phase riches with cerium oxide. XRD patterns of cerium con- taining glasses reflect the crystalline order of the glasses which is totally differed from that of cerium free glass, since amorphous character is the dominant.
10 Read more
According to the stratigraphical classification set up by Armstrong and Paterson (1970), the sediments described in this thesis lie within the 1525 m thick Garvock Group, towards the top of Lower Old Red Sandstone and are approximately Siegenian in age (Table 1.1). These sediments are composed largely of sandstone formations and represent the southeastern limb of Sidlaw Anticline (Fig. 1.1). The oldest subdivision of the Lower Old Red Sandstone (the Stonehaven Group) lies unconformably on Cambro-Ordovician rocks and is considered to be Infra-Gedinnian (topmost Silurian) in age (Mykura, 1983). On the basis of Rb-Sr dating of lavas (Arbuthnott Group), Thirlwall (1981 and 1983) suggested that a substantial part of the Lr, Old Red Sandstone could be of Silurian age, Westoll (1977), considering the spore content of the youngest subdivision (Strathmore Group), ascribed a middle Emsian age whereas plant remains such as Psilophyton ££inc£ps., JP,. golsi^chmidii. and .Arthrosiignia graclle suggest a late Siegenian date (Mykura, 1983). The Strathmore Group is overlain unconformably by Upper Old Red Sandstone.
337 Read more
Results in the present study indicated that 12, 10, 9, and 8 new protein patterns (bands) appeared in the treatments of calcium silicate, sodium silicate, potassium silicate, and silicon, respectively. In this respect, Ryals et al. (1996) re- ported that production and accumulation of PR proteins in plants in response to invading pathogen and/or stress con- ditions is very important. Phytoalexins are mainly produced by healthy cells adjacent to localized damaged and necrotic cells, but PR proteins accumulate locally in the infected and surrounding tissues and also in remote uninfected tis- sues. Production of PR proteins in the uninfected parts of plants can prevent the affected plants from further infection.
The initial step is extraction of silica from ash as sodium silicate using caustic soda. This reaction is carried out at a temperature in the range 180ºC-200ºC and pressure ranging from 6-8 atmospheres. But high reaction temperature and pressure can be avoided if ash obtained by burning rice husk at 650ºC is used. This ash is mostly amorphous silica which is reactive around 100ºC with NaOH solution at atmospheric pressure to yield sodium silicate.
Determination of fluid composition and structure at temperature and pressure conditions of the deep crust, upper mantle, and beyond is challenging because silicate-saturated fluids commonly do not retain in solu- tion the chemical components and the fluid structure that existed at the high temperature and pressure after temperature quenching from experimental conditions to ambient temperature and pressure. Various methods have been proposed with which to overcome these ob- stacles. For example, Kessel et al. (2004) described a method whereby fluids were soaked into layers of pore space among diamond particles during experiments. Analysis of these diamond aggregates after termination of an experiment provided the fluid data. Others rely on ac- curate weighing of crystals from the experimental charges before and after an experiment at high temperature and pressure during which crystalline material equilibrated with fluid (Manning and Boettcher 1994). The weight difference is the weight of the solute.
10 Read more