bluuebunny/crossref_metadata_2025_split huggingface dataset:
Medium-Range, Monthly, and Seasonal Prediction for Europe and the Use of Forecast Information
Authors: Rodwell Mark J. , Doblas-Reyes Francisco J. 
Published: December 2006

AbstractOperational probabilistic (ensemble) forecasts made at ECMWF during the European summer heat wave of 2003 indicate significant skill on medium (3–10 day) and monthly (10–30 day) time scales. A more general “unified” analysis of many medium-range, monthly, and seasonal forecasts confirms a high degree of probabilistic forecast skill for European temperatures over the first month. The unified analysis also identifies seasonal predictability for Europe, which is not yet realized in seasonal forecasts. Interestingly, the initial atmospheric state appears to be important even for month 2 of a coupled forecast.Seasonal coupled model forecasts capture the general level of observed European deterministic predictability associated with the persistence of anomalies. A review is made of the possibilities to improve seasonal forecasts. This includes multimodel and probabilistic techniques and the potential for “windows of opportunity” where better representation of the effects of boundary conditions (e.g., sea surface temperature and soil moisture) may improve forecasts. “Perfect coupled model” potential predictability estimates are sensitive to the coupled model used and so it is not yet possible to estimate ultimate levels of seasonal predictability.The impact of forecast information on different users with different mitigation strategies (i.e., ways of coping with a weather or climate event) is investigated. The importance of using forecast information to reduce volatility as well as reducing the expected expense is highlighted. The possibility that weather forecasts can affect the cost of mitigating actions is considered. The simplified analysis leads to different conclusions about the usefulness of forecasts that could guide decisions about the development of “end-to-end” (forecast-to-user decision) systems.
Hemispheric Insolation Forcing of the Indian Ocean and Asian Monsoon: Local versus Remote Impacts*
Authors: Liu Xiaodong , Liu Zhengyu , Kutzbach John E. , Clemens Steven C. , Prell Warren L. 
Published: December 2006

Abstract
Insolation forcing related to the earth’s orbital parameters is known to play an important role in regulating variations of the South Asian monsoon on geological time scales. The influence of insolation forcing on the Indian Ocean and Asian monsoon is studied in this paper by isolating the Northern and Southern Hemispheric insolation changes in several numerical experiments with a coupled ocean–atmosphere model. The focus is on the response of South Asian summer rainfall (monsoon strength) with emphasis on impacts of the local versus remote forcing and possible mechanisms. The model results show that both Northern Hemisphere (NH) and Southern Hemisphere (SH) summer insolation changes affect the Indian Ocean and Asian monsoon as a local forcing (in the same hemisphere), but only the SH changes result in remote (in the other hemisphere) forcing. The NH insolation change has a local and immediate impact on NH summer monsoons from North Africa to South and East Asia, while the SH insolation change has a remote and seasonal-scale delayed effect on the South Asian summer monsoon rainfall. When the SH insolation is increased from December to April, the sea surface temperature (SST) in the southern tropical Indian Ocean remains high from January to July. The increased SST produces more atmospheric precipitable water over the southern tropical Indian Ocean by promoting evaporation from the ocean. The enhanced precipitable water over the southern Indian Ocean is transported northward to the South Asian monsoon region by the lower-tropospheric mean cross-equatorial flows with the onset of the Asian monsoon increasing precipitable water over South Asia, eventually leading to the increase of Indian summer monsoon precipitation. Thus, these model experiments, while idealized and not fully representing actual orbitally forced insolation changes, confirm the broadscale response of northern monsoons to NH summer insolation increases and also illustrate how SH summer insolation increases can have a delayed influence on the Indian summer monsoon.
A method to determine the indicatrix of small crystals
Authors: Joel N. 
Published: December 2006

In the course of the investigation of the crystal structure of sodiumthyroxine- dl it appeared to be necessary, in order to find the approximate orientation of the molecule, to determine the orientation of the indicatrix and the values of the principal refractive indices.The crystals are flat and very thin (about 0-03 mm. thickness), and when put on a glass slide they all lie on their (100) face. This suggested the use of the universal stage, but the high birefringence of the crystals prevented it from giving good results. Moreover, as the crystals belong to the triclinic system and have no regular contour, it would have been difficult to refer the indicatrix to the unit cell. The interference figures seen when the crystals lie on a glass slide were mis-oriented, though sufficient to determine the sign of the indicatrix, and no clear interference figures could be seen when the crystals were far from horizontal.To overcome these difficulties the method which follows was developed, and proved to be very useful for all uniaxial crystals and highly birefringent biaxial crystals, whatever their habit.
Fluorescent felspar and zircon as petrological aids
Authors: Wilson Allan F. 
Published: December 2006

Although there have been many publications on the fluorescence MX. of minerals in ultra-violet light, very little systematic work has yet been done in utilizing this property for the elucidation of petrological problems, The response of various minerals would seem to be entirely capricious; but the extensive work done on phosphors shows that this depends on the presence of traces of impurities. The spectacular display given by certain minerals has made a strong appeal to amateur collectors.In 1943 the present writer made use of a fluorescent variety of zircon to assist in the subdivision of the Archaezoic gneisses and igneous rocks of the Mnsgrave Ranges in Central Australia; and after further fieldwork preliminary observations were published in 1947.
The growth and properties of large crystals of synthetic quartz
Authors: Brown C. S. , Kell R. C. , Thomas L. A. , Wooster Nora , Wooster W. A. 
Published: December 2006

In the last twenty years quartz has become of considerable importance to the telecommunications industry, one of its most important uses being the control of the frequency of oscillation of high-frequency transmitters. In this country alone the peak war-time demand for oscillator crystals was well over a million a year.Although quartz is very abundant in the earth's crust it is usually found in the polycrystalline state or as small crystals. Large crystals, reasonably free from twinning and flaws, are relatively rare and most of the supply for piezoelectric purposes comes from Brazil.
The powder patterns and lattice parameters of plagioclase felspars. I. The soda-rich plagioclases
Authors: Smith J. V. 
Published: December 2006

SummaryGeiger-counter powder records of soda-rich plagioclases have been carefully measured and indexed. The lattice parameters of the synthetic specimens are almost independent of the lime content, the largest variation (that in β*) amounting to only 0·2°. After strong heating the powder patterns of the natural specimens closely approached those of the synthetic specimens.Eight out of the nine natural plagioclases gave lattice parameters which fall within experimental error on a continuous line. There is a fairly large variation in lattice parameters, especially for γ*, which changes by 2°. As the lime content increases the lattice parameters of the natural plagioclases approach those for the high-temperature synthetic and heated natural specimens until at An50 the separation is only one-fifth of that at An0. The ninth specimen (from a dacite) gives parameters midway between the curves, thus exhibiting a state of partial inversion.The partially heated natural plagioclases and the plagioclase from the dacite give parameters indistinguishable within experimental error from the parameters of unheated plagioclases with a higher lime content. There is, therefore, no reliable powder X-ray method for the determination of composition in the region An0-An50. If the composition is known the powder method may be used for the determination of the thermal state. If the plagioclase can be judged to be in the low-temperature state from geological evidence the powder method can be used to estimate the composition with an accuracy of 2 % An.
Birnessite, a new manganese oxide mineral from Aberdeenshire, Scotland
Authors: Jones L. H. P. , Milne Angela A. 
Published: December 2006

SummaryA manganese pan near Birness contains grains of an optically uniaxial negative mineral near (Na0·7Ca0·3)Mn7O14·2·8H2O, giving an X-ray powder pattern similar to that of synthetic materials described as ‘manganous manganite’ and δ-MnO2. Material giving a similar pattern has been described from a natural occurrence in Canada, but no mineral name was assigned; the name birnessite is now proposed. The mineral is probably formed by air-oxidation of manganous oxides under alkaline conditions.
A note on albite twinning in plagioclase felspars
Authors: Gay P. 
Published: December 2006

SummaryPrevious work by Donnay on the basis of the geometrical theory of twinning related the width of albite twin lamellae to the composition of the plagioclase. The curve derived by Donnay has been recalculated for both high- and low-temperature felspars from X-ray data; the two curves differ markedly in the region between 0 and 20 % An. Some experimental evidence in support of the deductions that can be made is given.
The habit of pyrite in some sedimentary rocks
Authors: Smithson Frank 
Published: December 2006

SummaryAuthigenic pyrite crystals or their pseudomorphs found in heavy residues from sedimentary rocks are cubes, octahedra, or pyritohedra. Combinations of these forms are common; trapezohedron and rhombic dodecahedron faces are rare. The cube is most often recorded in the literature, but the octahedron is dominant in some districts and may be favoured by calcareous environment. X-ray tests have been applied and goethite and hematite detected as alteration products.
Accurate determination of the cell dimensions of magnetite
Authors: Basta E. Z. 
Published: December 2006

SummaryAn analysed magnetite from Bisperg, Säter, Dalecarlia, Sweden, gave the formula, which corresponds closely to the ideal composition. A precise determination of the cell dimensions gavea8·3963±0·0005 Å. at 18° C. Gentle heating of the powdered magnetite in evacuated silica glass tubes, before X-ray examination, resulted in sharply defined lines with high Bragg angles; an improvement which enabled precision data to be obtained. Four other new analyses of magnetites are also given and their lattice parameters are determined in the same way and are found to range from 8·3960 Å. to 8·3970 Å. The Bisperg magnetite being the purest sample examined, the value of its cell edge is taken as representative of pure magnetite.The effect of the different ionic substitutions on the cell dimensions of natural magnetites is discussed. An attempt is also made to explain the great variations among the published values of cell dimensions of artificial preparations; one main reason being the presence of defect structures with varying oxygen contents in excess of the formula requirements.
An X-ray investigation of some rare-earth silicates: cerite, lessingite, beckelite, britholite, and stillwellite
Authors: Gay P. 
Published: December 2006

SummaryAn X-ray study of a number of rare-earth silicates has been carried out; single-crystal and powder data are presented.It is found that cerites can contain up to at least 6 % CaO without disruption of the structure, which is trigonal with probable space-group P321 etc. The cell dimensions are a ca. 10·8 Å., c ca. 37–38 Å., although there is a strong pseudo-cell with halved c-axis. An ideal formula (Ca,Ln†)3Si2(O,OH,F)9 is proposed for this series.Lessingite and beckelite can be regarded chemically as lime-rich members of this cerite series. They do not, however, have the same crystal structure as cerite; their diffraction patterns are very similar to that of britholite, and indicate a structure dimensionally comparable with apatite. For a hexagonal cell, the dimensions are a ca. 9·7 Å., c ca. 7·1 Å., with probable space-group P63, &c. An ideal formula (Ca,Ln)2(Si,Al,P)(O,OH,F)5 is proposed for this series. Marked biaxial optical properties suggest that the structure may be truly orthorhombic, with a very close dimensional approximation to a hexagonal cell.The new mineral, stillwellite, is unrelated to either of these series. It is trigonal with cell dimensions a ca. 6·9 Å., c ca. 6·7 Å., with probable space-group P3112. An ideal formula (Ca,Ln)(Si,Al,P)B(O,OH,F)5 suggested by previous work is confirmed.
Sapphire-bearing rocks from MacRobertson Land, Antarctica
Authors: Segnit E. R. 
Published: December 2006

SummaryA small isolated outcrop in a large area of charnockites in the Mawson area, MacRobertson Land, Antarctica, consists of enstatite-sapphirine-cordierite rocks. Other highly magnesian outcrops occur in the district and these rocks may be completely recrystallized xenoliths. Analyses of the country rock, the two sapphirine-bearing rocks, and the sapphirine are given; the country rock is very rich in iron and has a high FeO : MgO ratio, while the sapphirine-bearing rocks are very low in iron and high in MgO, approximating to ternary mixtures of MgO, Al2O3, and SiO2.
The morphology of the baryte group
Authors: Seager A. F. 
Published: December 2006

SummaryThe observed order of importance of the forms of baryte, anglesite, and celestine is first determined by a modification of the methods used by Donnay and Harker. Their hypothesis is applied to determine the space-groups of these minerals by morphological means, and a comparison is made of the observed and theoretical orders of importance of forms in these minerals. It is concluded that agreement is poor between the observed and predicted frequencies of forms in the baryte group. The rank distribution of some of the more important forms is presented graphically.
A new method for orthoscopic adjustment with the Fedorov stage
Authors: Hallimond A. F. 
Published: December 2006

SummaryA new method is described to replace the standard procedure for completing the adjustment of an optical symmetry plane, with conditions for the accurate use of the biquartz. Extinction measurements are plotted to show the wide range of sensitivity (for the adjustment of A1 and A2) at various directions in the symmetry planes of a plagioclase. It is proposed that A1 and A2should be adjusted at different settings of A4 so as to obtain maximum sensitivity for each of those axes.
The Lewisian pegmatites of South Harris, Outer Hebrides
Authors: von Knorring O. , Dearnley R. 
Published: December 2006

SummaryA number of representative examples of the Lewisian acid pegmatites of South Harris are described, and the presence of the following minerals has been established: quartz, albite, microcline, biotite, muscovite, magnetite, beryl, spessartine, gahnite, eolumbite, monazite, zircon, pyrite, epidote, tourmaline, apatite, thorite, uraninite, thorogummite, uranophane, kasolite, betafite (?), and allanite. Spectrographic, optical, and X-ray powder data are given for some of these minerals, together with chemical analyses of magnetite, biotite, columbite, gahnite, and spessartine. It is believed that gahnite, nranophane, and the pyrochlore mineral (probably betafite) are recorded for the first time from Britain.
A note on a nordmarkite and an associated rare-earth mineral from the Ben Loyal syenite complex, Sutherlandshire
Authors: von Knorring O. , Dearnley R. 
Published: December 2006

SummaryA nordmarkite from the Ben Loyal syenite complex has been analysed, in which a powdery yellow mineral occurs in miarolitic cavities. The mineral may be a new hydrated species with a monazite structure and a chemical composition essentially that of monazite but with silicon partly replacing phosphorus and with magnesium, calcium, and iron partly replacing the rare earths.
Carminite and beudantite from the northern part of the Lake District and from Cornwall
Authors: Kingsbury Arthur W. G. , Hartley J. 
Published: December 2006

SummaryThe parageneses are given of ten new occurrences of carminite [PbFe2(AsO4)2(OH)2] and eleven of beudantite [PbFe3AsO4SO4(OH)6] in Cornwall and Cumberland, with an account of the alteration of carminite to beudantite and of beudantite to plumbojarosite or to beaverite.
X-ray data on stokesite
Authors: Gay P. , Rickson K. O. 
Published: December 2006

SummaryAn X-ray examination of the type specimen of stokesite gave a 14·41, b 11·61, c 5·23 Å.; space-group Pnna. The unit cell contains 4[CaSnSi3O11H4] and is derived from Hutchinson's morphological unit by the transformation [010/001/100]. X-ray powder data are given.
The dehydration of brucite
Authors: Ball M. C. , Taylor H. F. W. 
Published: December 2006

SummaryThis process has been reinvestigated, mainly with X-rays, using an FeO-containing, fibrous variety (nemalite), and also a nearly pure specimen. The results confirm that the transformation is oriented, thec- anda-directions of the brucite becoming the normals to (111) and (11̄0) in the periclase. There is an intermediate, spinel-like stage; the spinela-axis is parallel to, and twice as long as, that of the periclase. This stage is especially prominent when nemalite is heated in air or nitrogen, but is shown also by the nearly pure material. The nemalite shows also a further intermediate stage under certain conditions. A new hypothesis is proposed for the dehydration mechanism, in which the number of oxygen atoms per unit volume is ahnost unchanged in those parts of the crystal that are converted into periclase. The process is essentially one of cation migration, and the occurrence of the spinel-like phase is readily explained. Similar mechanisms possibly apply to the dehydration of other lamellar hydroxides and oxy-hydroxides (e.g. gibbsite, kaolinite) and of certain carbonates and other oxy-salts.
The use of petrographic methods for the identification of non-metallic inclusions in steel (plates XIII to XVI)
Authors: Nicholson C. G. 
Published: December 2006

SummaryIt is shown that petrographic methods, using the microscope and micro-refractometer, can be a valuable aid in the identification of non-metallic inclusions in steel, even when their size is only a small fraction of a millimetre. Special ways of preparing the samples are given, and some of the methods used in examination are indicated. Natural chromite, corundum, merwinite, mutlite, quartz, rhodonite, spincls, and zircon are taken as examples of the minerals found.
Polytypism of heterogenite
Authors: Deliens M. , Goethals H. 
Published: December 2006

SummaryA new variety of heterogenite was found in samples from Mindigi, Shaba, Zaïre. Photometric reflectance varies from 0·235 to 0·165 at λ 5890 Å in air. The bireflectance is 0·070, the degree of anisotropy is 0·7 and the main index in air is 2·7. A thermal weight-loss curve and a microprobe analysis are given and discussed, indicating the formula (Co,Ni) O.OH.The new variety, referred to as heterogenite-H, is hexagonal with cell dimensions a 2·85, c 8·80, space group P63/mmc and cell-content 2 [(Co, Ni)O.OH)]. Indexed X-ray powder data are given. A crystal structure is suggested based on CoO.OH octahedra layers and indicating a polytypic relation between heterogenite-H, the 2H form, and normal heterogenite, the 3R form.
Xonotlite and rodingites from Wairere, New Zealand
Authors: O'Brien J. P. , Rodgers K. A. 
Published: December 2006

SummaryXenoliths of eucritic gabbros in an alpine-serpentinite body at Wairere have been altered to rodingites and xonotlite about their margins by hydrothermal metasomatism at temperatures between 430–470°C A chemical analysis and the optical properties of the xonotlite are reported, the textures of the rocks are described, and the metasomatic process is discussed.
The cause of the colour of Blue John and other purple fluorites
Authors: Braithwaite R. S. W. , Flowers W. T. , Haszeldine R. N. , Russell M. 
Published: December 2006

Summary‘Blue John’ andother purple fluorites have been studied by a wide range of techniques. Hydrocarbons are not the cause of the colour of these fluorites. No significant difference in the concentrations of 73 elements between the purple and colourless zones of Blue John has been detected. The spectroscopic and thermal bleaching behaviour of the purple zones is consistent with the presence of ‘colloidal’ calcium as colouring agent, and coloration of fluorites with calcium vapour gives material showing similar properties. The distribution of colour suggests trapping of the calcium in lattice defects along {111} (cleavage) planes through {001} (growth) zones. The ‘colloids’ could be produced by aggregation of calcium atoms liberated by irradiation from sources found in the geological environment of Blue John. The banding could arise from variations in the concentration of lattice defects caused by variations in growth rates of the fluorite.
A study of the weathering of a biotite
using the Mössbauer effect
Authors: Goodman B. A. , Wilson M. J. 
Published: December 2006

Summary
The behaviour of iron in the weathering of
biotite in a sedentary soil profile developed on
appinite has been investigated using the Msbauer
effect. Both Fe2+ and
Fe3+ in sites with
cis and
trans hydroxyl groups
were observed at various stages in the weathering
sequence. The results indicate that there is
little or no ordering of the octahedral cations in
the fresh biotite and hydrobiotite, but in the
more weathered interstratified
vermiculite-chlorite samples
Fe3+ concentrates in the more
distorted sites. No evidence was obtained for the
presence of an anisotropic recoil-free
fraction.
Reverse zoning between myrmekite and albite in a quartzofeldspathic gneiss from Broken Hill, New South Wales
Authors: Phillips Evan R. , Stone Ian J. 
Published: December 2006

SummaryGrain boundary migration and the exsolution of albite from alkali feldspar, followed by the precipitation of myrmekite from the same source on to adjacent plagioclase grains, will explain the reversed zoning of these phases in contrast to the normal zoning seen in igneous rocks.
Compositional variation within staurolite crystals from the Ardara aureole, Co. Donegal, Ireland
Authors: Smellie J. A. T. 
Published: December 2006

SummaryStaurolite crystals from the aureole of the Ardara pluton have been analysed using the electron microprobe. Compositional variations of TiO2, MnO, and MgO take the form of irregular zoning, differences across sector twin boundaries, and variable marginal compositions, and can be attributed mostly to disequilibrium and localized diffusion.