There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

UV-Visible ار راد ن .د TiO2 ( تیفرظ راون مان هب نورتکلا یاراد یژرنا زارت لماش VB و ) رگید زارت ی یژرنا اب ( ییاناسر راون مان هب نورتکلا زا یلاخ و رتلااب VB یم ) .دشاب ت ود نیا نیب یژرنا توافت یژرنا فاکش زار ، پگ دناب هدیمان یم .دوش هک ینامز زا نورتکلا لاقتنا VB هب VB یم ماجنا دریگ ، TiO2 اب ودح یژرنا بذج د ev 2 / 3 ، نورتکلا تفج کی دیلوت یم هرفح .دیامن و نورتکلا هرفح ی نا اب هدش دیلوت یم کرتشم حطس هب لاقت ثعاب دناوت شنکاو ماجنا اه یی ددرگ . TiO2 دربراک ،دراد یدایز یاه هلمج زا یم ناوت اوه یگدولآ هیفصت یارب (CO2) و بآ و ... نآ زا هدافتسا درک .

Advanced Nanoarchitectures for Solar Photocatalytic Applications

Layered double hydroxides (LDHs) have been known for a considerable time and have been widely studied. The basic features of their structure, involving positively charged brucite-like layers together with charge-balancing anions and water in interlayer galleries are well understood, but some detailed aspects of their structure have been the subject of controversy in the literature. In this article we review the wide range of experimental and theoretical studies of the structure of LDHs, highlighting areas of consensus and currently unresolved issues. We focus on the range of composition for which LDHs may be formed, possible layer stacking polytypes, arrangement of guest species in the interlayer galleries and the extent of order-disorder phenomena, both long-range and short-range, in the layers and interlayer galleries.

Structural aspects of layered double hydroxides

Phosphorus (P) is an essential element for all life on earth. However, natural P resources (phosphate rock) are depleting. The authors describe the current situation and a forecast for future phosphate production and reserves. The current depletion of phosphate reserves and the increasingly stringent discharge regulations have led to the development of various P-recovery techniques from wastewater. Existing full-scale P-recovery techniques from the liquid phase, sludge phase, and sludge ash are reviewed. Although the full-scale P-recovery techniques have been shown to be technologically feasible, the economical feasibility, legislation and national policies are the major reasons why these techniques are not yet operational worldwide.

/pdf/global-phosphorus-scarcity-and-full-scale-p-recovery-h9ix77vxgy.pdf

Global Phosphorus Scarcity and Full-Scale P-Recovery Techniques: A Review

Both Raman and infrared spectroscopy have been used to characterise the three phase related minerals dreyerite (tetragonal BiVO4 ), pucherite (orthorhombic BiVO4) and clinobisvanite (monoclinic BiVO4 ) and a comparison of the spectra is made with that of the minerals namibite (Cu(BiO2)VO4(OH)), schumacherite ((Bi3O(OH)(VO4)2) and pottsite (PbBiH(VO4)2.2H2O). Pucherite, clinobisvanite and namibite are characterised by VO4 stretching vibrations at 872, 824 and 846 cm-1. The Raman spectrum of dreyerite shows complexity in the 750 to 950 cm-1 region with two intense bands at 836 and 790 cm-1 assigned to the symmetric and antisymmetric VO4 modes. The minerals schumacherite and pottsite are characterised by bands at 846 and 874 cm-1. In both the infrared and Raman spectra bands are observed in the 1000- 1100 cm-1 region which are attributed to the antisymmetric stretching modes. The Raman spectra of the low wavenumber region are complex. Bands are identified in the 328 to 370 cm-1 region and in the 404 to 498 cm-1 region and are assigned to the ν2 and ν4 bending modes. The minerals namibite and schumacherite are characterised by intense bands at 3514 and 3589 cm-1 assigned to the symmetric stretching vibrations of the OH units. Importantly Raman spectroscopy enables new insights into the chemistry of these bismuth vanadate minerals. Raman spectroscopy enables the identification of the bismuth vanadate minerals in mineral matrices where paragenetic relationships exist between the minerals.

/pdf/raman-spectroscopy-of-three-polymorphs-of-bivo4-195eko3jy1.pdf

Raman spectroscopy of three polymorphs of BiVO4: clinobisvanite, dreyerite and pucherite, with comparisons to (VO4)3-bearing minerals: namibite, pottsite and schumacherite

Thermal treatment of whewellite—a thermal analysis and Raman spectroscopic study

Struvite (NH4MgPO4·6H2O) is a mineral often found in urinary tracts and kidneys. Thermal decomposition using slow low heating shows that the 'kidney' stone can be decomposed at temperatures below 40°C. At this temperature both ammonia and water are evolved. If more rapid heating is employed the decomposition occurs at around 80°C. The implication of this work rests with the use of low slow heat for the decomposition of the kidney stones.

/pdf/thermal-decomposition-of-struvite-6nqmw05gwe.pdf

Thermal decomposition of struvite

/pdf/raman-and-infrared-spectroscopy-of-selected-vanadates-1j78q46q35.pdf

Raman and infrared spectroscopy of selected vanadates.

A comparative study of a suite of natural oxalates including weddellite, whewellite, moolooite, humboldtine, glushinskite, natroxalate and oxammite was undertaken using Raman spectroscopy at 298 and 77 K. Oxalates are found as films on host rocks as a result of heavy metal expulsion by primitive plants such as lichens and fungi. The minerals are characterized by the Raman position of the CO stretching vibration, which is cation sensitive. The band is observed at 1468 cm-1 for weddellite, 1464 cm-1 for whewellite, 1489 cm-1 for moolooite, 1489 cm-1 for humboldtine, 1471 cm-1 for glushinskite, 1456 cm-1 for natroxalate and 1473 cm-1 for oxammite. Except for oxammite, the infrared and Raman spectra are mutually exclusive, indicating that the minerals are bidentate and planar. Significant differences are observed in the CC stretching region and in the OCO bending region centred upon 910 and 860 cm-1, respectively. The significance of this work rests with the ability of Raman spectroscopy to identify oxalates which often occur as a film on a host rock. As such, Raman spectroscopy has the potential to identify the existence or pre-existence of life forms on planets such as Mars.

/pdf/raman-spectroscopy-of-natural-oxalates-at-298-and-77-k-3hgrp3u6oi.pdf

Matt L. Weier

Papers

Raman spectroscopy of three polymorphs of BiVO4: clinobisvanite, dreyerite and pucherite, with comparisons to (VO4)3-bearing minerals: namibite, pottsite and schumacherite

Thermal treatment of whewellite—a thermal analysis and Raman spectroscopic study

Thermal decomposition of struvite

Raman and infrared spectroscopy of selected vanadates.

Raman spectroscopy of natural oxalates at 298 and 77 K