scholarly journals Surface orange patinas on the limestone of the Batalha Monastery (Portugal): characterization and decay patterns

2021 ◽  
Author(s):  
Yufan Ding ◽  
Pedro Redol ◽  
Emma Angelini ◽  
José Mirão ◽  
Nick Schiavon
Keyword(s):  
Energy Dispersive Spectrometry ◽  
Minor Component ◽  
Soil Dust ◽  
X Ray ◽  
Chemical Attack ◽  
Ancient Monuments ◽  
A Minor ◽  
Orange Color ◽  
Ca Oxalate ◽  
Yellowish Orange

AbstractSamples of orange patinas found on a limestone window tracery and an ornament of the Batalha Monastery have been investigated by X-ray micro-diffractometry (μ-XRD) and low-vacuum scanning electron microscopy coupled with energy dispersive spectrometry (LV-SEM + EDS). The aim of the study was to determine the composition of the layered patinas, assess whether they have been intentionally applied or naturally formed, and study their degradation patterns. Preliminary results revealed that the orange patinas on the window tracery and the ornament showed different compositions and appearance, suggesting distinct formation pathways. Orange patinas on the ornament, which are now showing decay and delamination patterns, mainly consisted of gypsum with hematite as a minor component, implying the possibility of an intentional application of a mixture of ochre and lime as tint plaster. Orange patinas on the window tracery show, instead, the presence of Ca-oxalates, abundant weddellite, and minor whewellite, with minor hematite suggesting the yellowish/orange color as being due to Ca-oxalate patinas imbedding soil dust airborne particles. Such patina was possibly formed naturally either by the chemical attack due to atmospheric air pollutants from traffic exhausts emissions or by bacterial activity. No delamination was observed on the window tracery sample with granular decohesion as the major decay phenomenon. A comparison was made between this patina and the so-called scialbatura, a surface yellowish coating often found by conservators on limestone and marble in ancient monuments in the Mediterranean region.

scholarly journals Orange Layered Patinas on Limestone Surface in the Batalha Monastery (Portugal): Characterization and Decay Patterns

2021 ◽  
Author(s):  
YUFAN DING ◽  
Pedro Redol ◽  
Emma Angelini ◽  
Jose Mirao ◽  
Nick Schiavon
Keyword(s):  
Energy Dispersive Spectrometry ◽  
Minor Component ◽  
Soil Dust ◽  
Chemical Attack ◽  
Salt Decay ◽  
Ancient Monuments ◽  
A Minor ◽  
Orange Color ◽  
Ca Oxalate ◽  
Yellowish Orange

Abstract Samples of orange patinas found on a limestone balustrade and an ornament of the Batalha Monastery have been investigated by X-ray micro-diffractometry (µ-XRD) and Low-Vacuum Scanning Electron Microscopy coupled with Energy Dispersive Spectrometry (LV-SEM + EDS). Aim of the study was to determine the composition of the layered patinas, assess whether they were been intentionally applied or naturally formed, and study their degradation patterns. Preliminary results revealed that the orange patinas on the balustrade and the ornament showed different compositions and appearance, suggesting distinct formation pathways. Orange layers on the ornament which suffers salt decay and delamination nowadays, mainly consisted of gypsum with hematite as a minor component, implying the possibility of an intentional application of a mixture of ochre and lime as tint plaster. Orange patinas on the balustrade show the presence of Ca-oxalates, abundant weddellite and minor whewellite, with minor hematite suggesting the yellowish/orange color to be due to Ca-oxalate patinas imbedding soil dust airborne particles. Such patina was possibly formed naturally either by the chemical attack due to atmospheric air pollutants from traffic exhausts emissions or by bacterial activity. No delamination was observed, abrasion is the major decay phenomenon on the balustrade sample. A comparison was made between this patina and the so called “scialbatura”, a surface yellowish coating often found by conservators on limestone and marble in ancient monuments in the Mediterranean region.

On the atomic interdiffusion in Co/Pt superlattices

1992 ◽  
Vol 7 (6) ◽  
pp. 1309-1312 ◽  
Author(s):  
X. Yan ◽  
T. Egami ◽  
E.E. Marinero ◽  
R.F.C. Farrow ◽  
C.H. Lee
Keyword(s):  
Minor Component ◽  
Diffraction Experiment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Peaks ◽  
Large Width ◽  
A Minor ◽  
Component Parallel

We have performed x-ray diffraction experiments on MBE grown 〈111〉 and 〈001〉 oriented Co (3 Å)/Pt (18 Å) superlattices with the scattering vector Q covering a plane that includes a major component perpendicular and a minor component parallel to the plane of the sample. The superlattice diffraction peaks were found to have a large width parallel to the plane of the film, indicating that there is strong in-plane disorder. These broad peaks were integrated to evaluate more accurately the amount of interdiffusion at the interface, which was found to be similar in both films, contrary to what the conventional x-ray diffraction experiment suggests.

Fastigiatine, a lycopodium alkaloid with a new ring system

1986 ◽  
Vol 64 (5) ◽  
pp. 943-949 ◽  
Author(s):  
Robert V. Gerard ◽  
David B. MacLean ◽  
Romolo Fagianni ◽  
Colin J. Lock
Keyword(s):  
Mass Spectrum ◽  
Nmr Spectra ◽  
Minor Component ◽  
Ring System ◽  
Free Base ◽  
Relative Configuration ◽  
X Ray ◽  
H Nmr ◽  
Lycopodium Alkaloid ◽  
A Minor

Fastigiatine, C19H28N2O, is a minor component of the alkaloids of Lycopodiumfastigiatum R•Br•collected in New Zealand. Its structure and relative configuration have been resolved by an X-ray analysis of the free base. The pentacyclic ring system of fastigiatine has not been previously observed in the Lycopodium family of alkaloids or elsewhere. A proposal is presented for its derivation from the tetracyclic flabellidane ring system that is widely distributed among Lycopodium species. The mass spectrum and the 13C and 1H nmr spectra of fastigiatine are discussed.

scholarly journals A study of laser plasmas as X-ray sources in the 1–10 keV spectral region

1995 ◽  
Vol 13 (4) ◽  
pp. 493-501 ◽  
Author(s):  
S. Bastiani ◽  
S. Bastiani ◽  
A. Giulietti ◽  
L.A. Gizzi ◽  
T. Ceccotti ◽  
...  
Keyword(s):  
Spectral Region ◽  
Temporal Evolution ◽  
Streak Camera ◽  
Minor Component ◽  
Laser Pulses ◽  
X Ray ◽  
Laser Plasmas ◽  
Spectral Components ◽  
Main Component ◽  
A Minor

An experimental investigation on X-ray emission from laser-produced plasmas is presented and the properties of such an emission of interest for application purposes are examined. Plasmas were generated by focusing 1 μm, 3 ns Nd laser pulses onto Al and Cu targets at an intensity of 1013 W/cm2. The temporal evolution of the emission and its spectral features were investigated by using an X-ray streak-camera and an X-ray photodiode. In the case of Cu targets, the analysis of the emission showed two spectral components. The main component was centered at ≈ 1.2 keV and a minor component, whose intensity was measured to be 10-3 of the previous component, was observed at ≈7 keV. The X-ray conversion efficiency, in the investigated spectral region, was measured to be 1% for Cu targets and 0.3% for Al targets.

Study of thermal behaviour of 30Li2O·70TeO2glass by X-ray dynamic observation

2000 ◽  
Vol 33 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Taketoshi Taniguchi ◽  
Satoru Inoue ◽  
Takefumi Mitsuhashi ◽  
Akihiko Nukui
Keyword(s):  
High Temperature ◽  
Thermal Behaviour ◽  
Structural Changes ◽  
Minor Component ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Dsc Measurements ◽  
Thermal Changes ◽  
Endothermic Process ◽  
A Minor

The thermal behaviour of a 30Li2O·70TeO2glass was studied by use of anin situhigh-temperature X-ray diffractometer equipped with a position-sensitive detector (PSD). The dynamical structural changes were also observed by differential thermal analysis (DTA) and differential scanning calorimetry (DSC) measurements. Differences and contradictions exist in previous studies related to the phase relation at high temperature, including the process of phase change. It is found that in the exothermic process after a glass transition between 553 and 623 K, an unknown phase of lithium tellurite (LT-X) crystallizes at first. At almost the same temperature, a minor component of vitreous TeO2appears during decomposition of vitreous 30Li2O·70TeO2of the initial phase. After that, the thermal changes of the lithium tellurite and the TeO2components proceed independently. The LT-Xphase converts to α-Li2Te2O5, and the vitreous TeO2phase is followed by crystallization of an α-TeO2phase. In the endothermic process between 673 and 793 K, the α-Li2Te2O5phase transforms into a β-Li2Te2O5phase and the minor crystalline α-TeO2phase melts. Then, β-Li2Te2O5incongruently melts to form Li2TeO3and a molten TeO2phase. Li2TeO3continuously melts at around 763 K. The results show a possibility of reversible change between the α-Li2Te2O5and the β-Li2Te2O5phases.

scholarly journals Mineralogy of the Tertiary Clay Deposits in Makkah and Rabigh Quadrangles, West Central Arabian Shield, Saudi Arabia

2002 ◽  
Vol 7 (2) ◽  
pp. 259 ◽  
Author(s):  
M.H. Basyoni ◽  
M.A. El Askary ◽  
N.A. Saad ◽  
R.J. Taj
Keyword(s):  
Saudi Arabia ◽  
Minor Component ◽  
Arabian Shield ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Third ◽  
Rich Variety ◽  
Clay Deposits ◽  
Two Samples ◽  
A Minor

The mineralogy of the Tertiary clay deposits in Makkah and Rabigh quadrangles was thoroughly investigated by X-ray diffraction and differential thermal and thermogravimetric analyses in addition to other techniques. Results show that the investigated samples are predominantly composed of montmorillonite (Ca++ and/or Mg++ rich variety) and kaolinite, associated with subordinate illite and minor chlorite. Mixed layer montmorillonite-illite is recorded only in two samples. The relative abundance of these minerals by X-ray diffraction analysis showed that the studied clay deposits are of three types. The first, which is the most common, is highly montmorillonitic, the second is made up of a mixture of montmorillonite followed by kaolinite and illite and the third is highly kaolinitic with some montmorillonite. Generally, kaolinite shows a southward increase in Makkah quadrangle while chlorite, as a minor component, shows a northward increase in Rabigh quadrangle.                                                 

scholarly journals Zur Reaktion von (CO)4FeP(R)Cl2 mit Na2Cr2(CO)10 / Reactions of (CO)4FeP(R)Cl2 with Na2Cr2(CO)10

1986 ◽  
Vol 41 (5) ◽  
pp. 532-540 ◽  
Author(s):  
Jutta Borm ◽  
Konrad Knoll ◽  
Laszlo Zsolnai ◽  
Gottfried Huttner
Keyword(s):  
Spectroscopic Data ◽  
Minor Component ◽  
Major Product ◽  
High Yield ◽  
Analogous Reaction ◽  
X Ray ◽  
A Minor

(CO)4FeP(R)Cl2 reacts with Na2Cr2(CO)10 to give the μ3 RP capped trigonal heterom etallic closed cluster Fe(CO)3Cr(CO)4Cr(CO)5(μ3-PR)(1) as a major product. ACr(CO)5-derivative of a metal substituted phosphane [(μ2(tBuPCl)Fe2(CO)7)(tBuPH)]Cr(CO)5 (2) is obtained as a minor component.The analogous reaction with (CO)4FeP(Ph)Cl2 only gives the known cluster Fe3(CO)9(μ3-PR)2 (3), while (CO)4FeP(c-hexyl)Cl2 results in 4, a pentacarbonylchromiumderivative of the diiron species Fe2(CO)6μ-(PR)3. Species o f this type, containing an Fe2(CO)6 entity doubly bridged by μ2-PR entities, which are them selves linked by another PR-group, are obtained in a systematic high yield process by reacting Fe2(CO)6(μ2-RPH)2 with n-BuLi/TMEDA , RPCl2. For com pound identification, analytical and spectroscopic data as well as four X-ray analyses are presented.

Protonation effects on dynamic flux properties of aqueous metal complexes

2009 ◽  
Vol 74 (10) ◽  
pp. 1543-1557 ◽  
Author(s):  
Herman P. Van Leeuwen ◽  
Raewyn M. Town
Keyword(s):  
Complex Formation ◽  
Metal Ion ◽  
Good Description ◽  
Minor Component ◽  
Outer Sphere ◽  
Metal Species ◽  
Central Metal ◽  
Inner Sphere ◽  
A Minor ◽  
Protonated Ligand

The degree of (de)protonation of aqueous metal species has significant consequences for the kinetics of complex formation/dissociation. All protonated forms of both the ligand and the hydrated central metal ion contribute to the rate of complex formation to an extent weighted by the pertaining outer-sphere stabilities. Likewise, the lifetime of the uncomplexed metal is determined by all the various protonated ligand species. Therefore, the interfacial reaction layer thickness, μ, and the ensuing kinetic flux, Jkin, are more involved than in the conventional case. All inner-sphere complexes contribute to the overall rate of dissociation, as weighted by their respective rate constants for dissociation, kd. The presence of inner-sphere deprotonated H2O, or of outer-sphere protonated ligand, generally has a great impact on kd of the inner-sphere complex. Consequently, the overall flux can be dominated by a species that is a minor component of the bulk speciation. The concepts are shown to provide a good description of experimental stripping chronopotentiometric data for several protonated metal–ligand systems.

scholarly journals X-ray and Neutron Study on the Structure of Hydrous SiO2 Glass up to 10 GPa

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 84 ◽  
Author(s):  
Satoru Urakawa ◽  
Toru Inoue ◽  
Takanori Hattori ◽  
Asami Sano-Furukawa ◽  
Shinji Kohara ◽  
...  
Keyword(s):  
Oxide Glasses ◽  
Void Space ◽  
X Ray Diffraction ◽  
Amorphous Sio2 ◽  
Sio2 Glass ◽  
X Ray ◽  
X Ray Scattering ◽  
Medium Range ◽  
Two Phases ◽  
A Minor

The structure of hydrous amorphous SiO2 is fundamental in order to investigate the effects of water on the physicochemical properties of oxide glasses and magma. The hydrous SiO2 glass with 13 wt.% D2O was synthesized under high-pressure and high-temperature conditions and its structure was investigated by small angle X-ray scattering, X-ray diffraction, and neutron diffraction experiments at pressures of up to 10 GPa and room temperature. This hydrous glass is separated into two phases: a major phase rich in SiO2 and a minor phase rich in D2O molecules distributed as small domains with dimensions of less than 100 Å. Medium-range order of the hydrous glass shrinks compared to the anhydrous SiO2 glass by disruption of SiO4 linkage due to the formation of Si–OD deuterioxyl, while the response of its structure to pressure is almost the same as that of the anhydrous SiO2 glass. Most of D2O molecules are in the small domains and hardly penetrate into the void space in the ring consisting of SiO4 tetrahedra.

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