bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Tomhannock Creek, New York, chondrite
Authors: Mason Brian , Wiik H. B. 
Published: December 2006

SummaryThe Tomhannock Creek chondrite has been analysed, with the following results: Fe 11·36, Ni 1·69, Co 0·07, FeS 5·26, SiO2 36·88, TiO2 0·135, Al2O3 1·80, Cr2O2 0·30, FeO 14·94, MnO 0·31, MgO 23·81, CaO 1·39, Na2O 0·73, K2O 0·095, P2O5 0·36, H2O+ 0·34, C 0·10; total 99·57. The mineralogical composition is olivine (Fo81), hypersthene (En83), plagioclase (An22), nickel-iron, troilite, chromite, and probably apatite. The density of the meteorite is 3·65.Tomhannock Creek is not identical with Homestead, nor with Yorktown. Yorktown is a chondrite that appears to have fallen near Yorktown, Westchester County, New York (41° 17′ N., 73° 49′ W.), in September 1869.
A thermodynamic analysis of the system anorthite-åkermanite
Authors: de Wys E. Christiaan 
Published: December 2006

SummaryFrom thermodynamic considerations of the system anorthite-åkermanite it appears that the melts in this system are ionic in nature. The liquidus relation in this system would thus seem to afford confirmation of the theory, based on conductivity measurements, that silicate melts such as molten anorthite dissociate into such ions as Ca2+ and (Al2Si2O8)2−.Further thermodynamic calculations involving no unreasonable assumption lead to a close reproduction of the experimental liquidus curve of åkermanite. This lends added strength to the belief in the stable existence of åkermanite down to the eutectic; no evidence in support of the claim that åkermanes becomes unstable below 1 325° C. (Osborn and Schairer, 1941) was encountered.According to Osborn et al. (1954) the presence of substantial Ca2+ increases the desulphurizing potential of blast furnace slag. The thermodynamic treatment of the binary system anorthite-åkermanite leads to the conclusion that both phases dissociate in the molten state and in mutual solution to yield Ca2+; it therefore appears probable that a high concentration of these minerals in the slag would have a salutary effect on the slag chemistry.
On the lithium amphibole holmquistite, from Benson pegmatite mine, Mtoko, Southern Rhodesia
Authors: von Knorring O. , Hornung G. 
Published: December 2006

SummaryA new occurrence of holmquistite is described. The mineral is found in amphibolite at the contact of a lithium pegmatite. Chemical analyses and optical data of the holmquistite and an associated hornblende are given.
Methods for the chemical analysis of meteorites. I. Siderites
Authors: Moss A. A. , Hey M. H. , Bothwell D. I. 
Published: December 2006

SummarySimple chemical procedures (colorimetric and gravimetric) for the determination of Co, Cr, Cu, Ga, Ni, P, and S in an iron meteorite or in the separated metallic phase of a pallasite are described; the minimum size of sample is discussed. A procedure for the quantitative removal of the metallic, sulphide, and phosphide phases from a stone or siderolite is described, and is applicable to the quantitative isolation of silicate and oxide inclusions from siderites (other than some very high in nickel).
Heyite, Pb5Fe2(VO4)2O4 , a New Mineral from Nevada
Authors: Williams Sidney A. 
Published: December 2006

SummaryHeyite occurs in silicified limestone with other oxidation-zone minerals derived from galena, chalcopyrite, and pyrite. The occurrence is near Ely, Nevada. Most common are pyromorphite, cerussite, and chrysocolla. Heyite occurs on and replaces corroded tungstenian wulfenite. Crystals are small (up to 0·4 mm), simple in habit, and monoclinic. Only {001}, {100}, {110}, and {01} have been observed. Twinning on {110} is relatively common. The colour is yellow-orange with a yellow streak, H = 4. Electron probe analyses (average of three) gave PbO 75·4 %, ZnO 0·81 %, FeO 8·41 %, V2O5 12·65 %. This leads to Pb5(Fe,Zn)2(VO4)2O4, with Z = 1.The space group is P21/m. Cell constants, refined from powder data, are a 8·910 Å, b 6·017, c 7·734 (all ±0·004 Å); β III° 53′±4′. The strongest powder lines (Cr-Kα) are: 3·248, 11, (100); 2·970, 30, 21 (69); 2·767, 211 (61); 4·873,110, (46); 3·674, 111, (35); 2·306 (33); 3·010, 020, (29); 3·412, 20, 11, (25); 8·281, 100, (25); and 2·113 (20). Gcalc 6·284, Gmeas 6·3±0·2 Optically biaxial with 2Vγ 82°calc, 89°meas; αD 2·185, βD 2·219, γD 2·266; all values ±0·01 and determined in S-Se melts. Dispersion is weak with π > ν. The orientation is β = b, α: [001] 36° (in obtuse β). Nonpleochroic.Three small specimens were found, and represent a total of less than 100 mg of the mineral. One has been deposited with the British Museum (Natural History). The name is for Dr. Max Hey, eminent British chemist and mineralogist.The cell is strikingly similar to that of brackebuschite but electron probe examination of a newly analysed (by atomic absorption) specimen of the latter from the type locality in Argentina shows a marked chemical difference. Heyite strongly resembles descloizite in appearance.
Ortho- and Clino-Pyroxenes from the Charnockite Series of Amaravathi, Andhra Pradesh, South India
Authors: Ramaswamy A. , Murty M. S. 
Published: December 2006

SummaryThe chemical analyses, structural formulae, and optical data of seven orthopyroxenes and six clinopyroxenes, all from the charnockite series of Amaravathi, are presented. The orthopyroxenes are in the hypersthene-ferrohypersthene range while the clinopyroxenes are in the sahlite range. The aluminous nature of the pyroxene is believed to be the result of high pressure. The clinopyroxenes have the granulite trend on the Wo-En-Fs plot. The tie-line projections and the KD values for the pyroxene pairs indicate conditions of chemical equilibrium around 670 °C for the charnockite series of Amaravathi.
The development of crystalline structure in aluminium hydroxide polymorphs on ageing
Authors: Elderfield H. , Hem J. D. 
Published: December 2006

SummaryInfrared absorption spectra of the precipitated solids separated from aluminium-hydroxide solutions below the pH of minimum solubility of Al(OH)3 demonstrate the slow ageing of polymeric Al complexes to gibbsite. On comparison with the spectra of natural gibbsites, shifts in absorption frequency during crystal growth are interpreted in terms of changes in hydrogen bonding as a consequence of deprotonation and stacking of aluminium hydroxide layers to form gibbsite. In alkaline solutions the bayerite polymorph precipitates and IR frequencies are compatible with protonation as aluminate ions associate with the bayerite crystal having a lower crystal energy than its low pH polymorph. The infrared spectrum of nordstrandite, which is probably the stable polymorph in alkaline solution, shows evidence of strongly polarized hydroxyl ions similar to gibbsite.
Composition of chromites in cordierite-and mica-bearing Cr-Ni ores from Málaga Province, Spain
Authors: Oen I. S. , Kieft C. , Westerhof A. B. 
Published: December 2006

SummaryAn unusual paragenesis of chromite, nickeline, cordierite, and red-brown mica occurs in veins, pods, and schlieren in serpentinized ultramafic rocks at La Gallega and Los Jarales in Máilaga province, Spain. The chromites in this paragenesis are low-ferric, ferrous-rich aluminous chromites with exceptionally high vanadium content ranging between 1·8 and 2·9 wt % V2O3and high zinc content ranging between 0·5 and 1·0 wt % ZnO. A comparison of chromite composition with available experimental data, together with paragenetical and textural evidence, suggests that the chromite, cordierite, and red-brown mica crystallized at magmatic temperatures between approximately 1300° and 1000°C at low oxygen fugacities and maximum pressures below 10 kb, probably near 5 kb.
The Kabo, Nigeria, meteorite fall
Authors: Hutchison R. , Ajakaiye D. E. , Elliott C. J. , Fry F. A. 
Published: December 2006

SummaryAt least four stones fell over a distance of about 9 km at the end of a west to east trajectory on 25 April 1971 at about 1630 hours local time. Their approximate location is 11° 51′ N., 8° 13′ E. About 13·4 kg of this xenolithic bronzite chondrite, class H4, were recovered. A bulk chemical analysis with total Fe = 29°4 % (wt), is presented. Olivine is Fa18.9 (molec.) in composition. Concentrations of the cosmogenic radionuclides 22Na, 26Al, and 54Mn were 71±6, 56±5 and 84±6 dpm/kg, respectively.
Crystal structures of some double hydroxide
minerals
Authors: Taylor H. F. W. 
Published: December 2006

Summary
Three groups of minerals are discussed,
which are typified by pyroaurite and sjögrenitc,
hydrocalumite, and ettringite. All show
interesting structural features. In the
pyroaurite-sjögrenite group, brucite-likc layers
carrying a net positive charge alternate with
layers in which the oxygen atoms of carbonate
groups and water molecules are statistically
distributed on a single set of sites; other anions
may replace the carbonate, especially in synthetic
phases. Hydrocalumite and related synthetic phases
also have layer structures in which positively
charged main layers alternate with intermediate
layers containing anions and water molecules; the
anions occur in cavities and their nature can
again vary widely. In the ettringite group, the
structures are based on positively charged
columns, between which occur channels containing
anions and sometimes also water molecules. This
group includes thaumasite, the only natural
mineral known to contain silicon six-coordinated
by oxygen that is not a high-pressure phase. The
thermal dehydration behaviour in each group is
briefly considered.
The crystal chemistry of the amphiboles II Refinement of the crystal structure of oxy-kaersutite
Authors: Hawthorne F. C. , Grundy H. D. 
Published: December 2006

SummaryThree-dimensional counter-diffractometer data corrected for absorption and a full matrix least-squares method have been used to refine the crystal structure of an oxy-kaersutite in the space groupC2/m. The chemical composition of the amphibole is with cell parametersa9·8920(11),b18·064(2),c5·3116(7)Å and β 105·388(5)°. Cation site occupancies were refined using bulk chemical constraints and the A-site positionally disordered. The final conventionalR-factor for 1041 observed reflections is 4·0%.The rotation of the tetrahedral chains in calcic clino-amphiboles is shown to be a function of the Alivcontent of the tetrahedral sites. Comparison of this oxidized amphibole with an hydroxyamphibole of similar chemical composition indicates that on oxidation the maximum amount of structural relaxation takes place in the vicinity of theM(I) octahedra, which distort to a high-energy configuration.
Hydrothermal synthesis of albite: the
effect of NaOH on Obliquity
Authors: Trembath L. T. 
Published: December 2006

Summary
A series of albites was synthesized in the
presence of aqueous NaOH fluids (concentration 0
to 4N NaOH,
Pfluid
= 15000 1b/in2) over the
temperature range 300 to 500 °C. At fixed
temperature-pressure conditions increasing NaOH
concentration of the initial fluid can be
correlated with decreasing obliquity of the
albites.
Conjugate cummingtonite and hornblende at
Sgeir nan Sgarbh, South Harris, Outer
Hebrides
Authors: Livingstone A. , Frost M. T. , Suddaby P. 
Published: December 2006

Summary
Chemical analyses, cell parameters, and
optical data are presented for conjugate
cummingtonite and hornblende, which occur in a
paragneiss. A metasomatic origin for the
development of hornblende from cummingtonite,
during retrogressive metamorphism, is
proposed.
Crystallization trend of titanomagnetites
in an alkali basalt from Saint-Clément (Massif
Central, France)
Authors: Prévot M. , Mergoil J. 
Published: December 2006

Summary
Three generations of homogeneous
titanomagnetite in a hawaiite from Saint-Clément
may be defined by differences in size, habit, or
reflectance, and are believed to correspond to
different crystallization stages of the lava.
Chemical compositions were determined by electron
microprobe, and by X-ray and thermomagnetic
methods.
Larger crystals are of intratelluric
origin and occur either as inclusions in
phenocrysts of early clinopyroxene (generation 1)
or separately in the groundmass (generation 2); in
the latter case, they always show evidence of
resorption. Post-eruptive titanomagnetite
(generation 3) is smaller and so highly oxidized
that it is better termed titanomaghemite. Since
the maghemitization, which is a low temperature
process, alters the metallic ratios (especially
the Fe/Ti ratio) the metallic contents at the time
of the high-temperature crystallization are
exactly known only for the intratelluric
titanomagnetites.
As intratelluric crystallization proceeds
Ti content increases greatly (5 to 14%); Mn also
increases (but slightly), A1 and Mg decrease,
while results for Cr are inconclusive. Apparently
these changes go on until the post-eruptive
crystallization stage.
The titanium trend is contrary to common
belief. However, it is in accordance with
predictions from the Fe-Ti-O system and may be
explained by a decrease in oxygen fugacity during
magma ascent.
Nahcolite (NaHCO3) in inclusions in apatites from some E. African ijolites and carbonatites
Authors: Rankin A. H. , Le Bas M. J. 
Published: December 2006

SummaryNahcolite (NaHCO3) is identified and recorded for the first time from an igneous rock. Often associated with it is another carbonate mineral tentatively identified as kalicine (KHCO3), which has not previously been recorded as a primary mineral in any rock. These minerals occur in inclusions in apatite crystals in ijolites and carbonatites, and indicate that both ijolite and carbonatite magma must have been considerably richer in soda and potash than is indicated by the chemical analyses of the rocks. The identification was made by a combination of microchemical, solubility, crystallographic, and optical determinations.
Examples of twinning and parallel growth in zircons from some Precambrian granites and gneisses
Authors: Jocelyn J. , Pidgeon R. T. 
Published: December 2006

SummaryGrowth twins, parallel growths, and necked crystals are described from zircon populations from granitic gneisses from the Precambrian of SW. Greenland. From observations of the distribution of internal growth zones it is concluded that whereas twinning takes place early in the growth history of elbow twins it can occur at any time during crystallization of the zircon. Parallel growth is attributed to a process of synneusis or attachment of zircons that have initially undergone separate growth histories. This implies that viscosity conditions of the rocks were low enough to permit the movement and collision of growing zircon crystals. The common occurrence of zircons with central constrictions, sometimes superimposed on transverse fractures, in zircon suites from the granitic gneisses is explained in terms of late-stage chemical corrosion accompanied by brittle fracturing.
Phosphate minerals from Reaphook Hill, Flinders Ranges, South Australia
Authors: Hill R. J. , Milnes A. R. 
Published: December 2006

SummarySeveral uncommon phosphate minerals including tarbuttite, parahopeite, scholzite, and collinsite occur in near-surface gossans at the Reaphook Hill zinc prospect. Electron-probe microanalyses of the tarbuttite and scholzite compare well with published analyses of specimens of these minerals from the type localities in Zambia and Bavaria respectively. However, microanalyses of the parahopeite are significantly different from published analyses of parahopeite, and suggest that it may be one member of an isomorphous series in which six-coordinated Zn can be replaced by other cations, including Fe, Mg, and Mn. Furthermore, crystals of the Reaphook Hill parahopeite are compositionally zoned with their centres enriched in Fe and Mn relative to the margins, which are enriched in Mg.Zincian collinsite occurs at Reaphook Hill as concentric crusts composed of very fine grained radially oriented plates. Electron-probe microanalyses of this material are significantly different from published analyses of collinsite from the type locality in British Columbia: Zn instead of Fe occupies the divalent cation sites; this material may be part of an isomorphous series that includes fairfieldite. Microanalyses also indicate that the Reaphook Hill collinsite crusts are compositionally zoned such that Zn:Mg ratios vary from the base to the outer edges of the crusts. This zoning is interpreted as the result of variation in the availability of Zn and Mg during growth. Zoning of similar type, but due to variation in the Fe: Mg ratio, was observed in concentric crusts of collinsite from the type locality in British Columbia.
The anomalous optical absorption spectrum of low zircon
Authors: Vance E. R. 
Published: December 2006

SummaryFurther lines of the anomalous optical absorption spectrum in low metamict zircon have been observed in the infra-red. Low-temperature polarization studies have enabled a clear distinction to be made between lines due to the anomalous spectrum and those due to the normal spectrum of U4+ in zircon. Magnetic circular dichroism measurements showed, for the anomalous spectrum, only contributions due to the mixing of the energy levels by the magnetic field; thus the A spectrum results from singlet → singlet transitions. The anomalous spectrum appears to derive from U4+ incorporated in polycrystalline zirconia.
Porphyroblastesis and displacement: some new textural criteria from pelitic hornfels
Authors: Saggerson E. P. 
Published: December 2006

SummaryThe formation of porphyroblasts by replacement and displacement of pre-existing S surfaces is examined in the light of textural evidence displayed by sediments hornfelsed by the Bushveld Igneous Complex. Helicitic biotite, staurolite, and cordierite all show replacement and displacement textures, the former being more common. The evidence indicates that porphyroblasts arc capable of creating local pressure differences that disturb the pre-existing banding, even in hornfelsed rocks that have suffered neither regional metamorphism nor orogenic movement.
Are vashegyite and kingite hydrous aluminum phyllophosphates with kaolinite-type structures ?
Authors: McConnell Duncan 
Published: December 2006

SummaryIn contrast with some other hydrous aluminum phosphates, vashegyite is crystalline. Simultaneous application of several assumptions leads to the hypothesis that it has a structure analogous to that of kaolinite, and thus contains tetrahedral sheets, n[X2O5], where X is both P and H3 (in lieu of Si). Thus, the theory involving [HXO4] is extended from phosphates with isolated tetrahedral groups [XO4] and framework linkages [XO2] to sheet linkages [X2O5]. Kingite also may have a kaolinite-like structure.
High-Risk Human Papillomavirus Affects Prognosis in Patients With Surgically Treated Oropharyngeal Squamous Cell Carcinoma
Authors: Licitra Lisa , Perrone Federica , Bossi Paolo , Suardi Simona , Mariani Luigi , Artusi Raffaella , Oggionni Maria , Rossini Chiara , Cantù Giulio , Squadrelli Massimo , Quattrone Pasquale , Locati Laura D. , Bergamini Cristiana , Olmi Patrizia , Pierotti Marco A. , Pilotti Silvana 
Published: December 2006

PurposeHuman papillomavirus (HPV) DNA tumors actively integrating the E6 and E7 oncogenes have a distinct biologic behavior resulting in a more favorable prognosis. To which extent the viral integration by itself, and/or the associated wild-type (wt) TP53 status, and/or a functional p16 contribute to prognosis is unclear.Patients and MethodsTo clarify how the presence of high-risk (HR) -HPV, TP53, and p16INK4astatus interact with clinical outcome, we considered a retrospective series of 90 consecutive oropharyngeal cancer patients treated primarily with surgery.ResultsSeventeen (19%) patients showed integrated HPV 16 DNA (HPV positive), wt TP53 in all but two patients, normal p16INK4ain 15 assessable patients, and p16 expression in all 17 patients. Thirty-five patients (39%), two of whom were HPV positive, harbored TP53 mutations. p16INK4adeletion and p16 null immunophenotype occurred in 28 and 58 patients, respectively, and was similarly distributed in both patients with mutated TP53 (48% and 82%, respectively) and in patients with wt TP53 (46% and 77%, respectively). Statistical analysis showed that HPV-positive status significantly affects all investigated end points: overall survival (P = .0018), incidence of tumor relapse (P = .0371), and second tumor (P = .0152), whereas TP53 and p16INK4astatus and p16 expression were not prognostic by themselves.ConclusionOur molecular and clinical results are in agreement with previous findings but provide additional information into the biologic mechanisms involved in HR-HPV oropharyngeal cancer in comparison to HPV-negative tumors. According to the reduced risk of relapse and second tumors associated with HR-HPV positivity of oropharyngeal cancer, the therapeutic strategy and follow-up procedures should be reviewed.
The pH Rule for Fabricating Composite CoCu Nanowire Arrays
Authors: Liu Xiaoxu , Zhao Jianling , Li Yangxian , Xu Shifeng , Zhu Zhiyong , Chen Jinglan , Wu Guangheng 
Published: December 2006

Abstract
A series of Co1−xCux (x = 0.05–0.70) composite nanowire arrays have been electrodeposited in alumina templates. An apparent pH value rule for nanowire phase and composition has been found. Based on it, composite nanowires can be obtained and the composition becomes more controllable. In the composite nanowires, the cubic and hexagonal structures coexisted. The specific magnetic properties, coercivity and squareness of the composite arrays are enhanced by three times, apparently preceding to those in single phase nanowires.
Determination of Silver Ion with Cadmium Sulfide Quantum Dots Modified by Bismuthiol II as Fluorescence Probe
Authors: Lai Shoujun , Chang Xijun , Mao Jie , Zhai Yunhui , Lian Ning , Zheng Hong 
Published: December 2006

AbstractCdS quantum dots (QDs) modified with bismuthiol II potassium salt is prepared in one step. Based on the characteristic fluorescence enhancement of CdS QDs at 480 nm by silver ions, simultaneously, a red shift of fluorescence emission bands of CdS QDs from 460 to 480 nm is observed. A simple, rapid, sensitive and specific detection method for silver ion is proposed. Under optimum conditions, the fluorescence intensity of CdS QDs was linearly proportional to silver ion concentration from 0.01 to 5.0 μmol L‐1 with a detection limit of 1.6 nmol L‐1. In comparison with single organic fluorophores, functionalized CdS quantum dots are brighter, more stable against photobleaching and do not suffer from blinking. Furthermore, the proposed method shows higher sensitivity and selectivity. A possible fluorescence enhancement mechanism is also studied.
New Fluorimetric Determination of Hemoglobin Used as a Substitute of Mimietic Peroxidase
Authors: Qin Shihui 
Published: December 2006

AbstractHemoglobin (Hb) could be used as a substitute of peroxidase in the catalytic oxidation of tetra‐substituted amino aluminum phthalocyanine (TAAlPc) by H2O2. We found that the fluorescence of TAAlPc (a red‐region fluorescent dye with a maximum excitation wavelength at 606 nm and a maximum emission wavelength at 673 nm) could significantly be quenched by H2O2 in the presence of Hb. The value of FO/F (where the relative fluorescence intensity of blank solution and that of the sample solution containing Hb were given by FO and F, respectively) is linearly related to the concentration of Hb. Based on this, a novel fluorimetric method was developed for the determination of Hb in aqueous solution. Under optimal conditions, Hb could be determined in the concentration range of 5 × 10‐11‐1.2 × 10‐8 mol L‐1 with a detection limit of 1.5 × 10‐11 mol L‐1. The relativestandard deviation of ten replicate measurements was 1.95 % for solution containing 1 × 10‐9 mol L‐1 Hb. The proposed method has been applied to the analysis of Hb in human blood and the results were in good agreement with those reported by a hospital laboratory. So this is a new, high sensitive and precise fluorescence quenching method to determine Hb.