Sustainable Improvement of Zeolitic Pyroclastic Soils for the Preservation of Historical Sites

Climate changes are inducing a modification of environmental loads on historical sites, requiring new actions towards their conservation. In the paper, the results of an experimental work on sustainable improvement of a pyroclastic soil belonging to the Orvieto cliff (Central Italy) have been investigated in the perspective of its preservation from degradation. The slightly coherent facies of Orvieto Ignimbrite (pozzolana) was treated with hydrated lime and the subsequent chemo-physical evolution was investigated by means of a multi-scale analysis. The beneficial effects obtained from the improvement in terms of mechanical behaviour were interpreted and correlated to the chemo-physical evolution of the system. Microstructural analyses, X-ray diffractometry, thermo-gravimetric analyses (DTG), SEM observations, mercury intrusion porosimetry performed on raw and treated samples, showed that the pozzolanic reactions develop since the very beginning in the system and that the observed mechanical improvement of the treated soil is mainly due to the formation of calcium silicate hydrates (CSH) and calcium aluminate hydrates (CAH). In the paper, the mechanical improvement is put in evidence by comparing the results of oedometer tests performed on both raw and treated samples.

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Multi-scale Investigation of Heterogeneous Swift Heavy Ion Tracks in Stannate Pyrochlore

Journal of Materials Chemistry A ◽

10.1039/d1ta04924k ◽

2021 ◽

Author(s):

Eric O'Quinn ◽

Cameron Tracy ◽

William F. Cureton ◽

Ritesh Sachan ◽

Joerg C. Neuefeind ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Heavy Ion ◽

X Ray Diffraction ◽

X Ray ◽

Structural Modifications ◽

Multi Scale ◽

Ion Tracks ◽

Swift Heavy Ion ◽

Transmission Electron

Er2Sn2O7 pyrochlore was irradiated with swift heavy Au ions (2.2 GeV), and the induced structural modifications were systematically examined using complementary characterization techniques including transmission electron microscopy (TEM), X-ray diffraction...

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Multi-Scale Modeling of Neural Structure in X-Ray Imagery

10.1109/icip42928.2021.9506174 ◽

2021 ◽

Author(s):

Aishwarya Balwani ◽

Joseph Miano ◽

Ran Liu ◽

Lindsey Kitchell ◽

Judy A. Prasad ◽

...

Keyword(s):

Neural Structure ◽

X Ray ◽

Multi Scale ◽

Scale Modeling ◽

Multi Scale Modeling

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Multi-Scale Studies of 3D Printed Mn–Na–W/SiO2 Catalyst for Oxidative Coupling of Methane

Catalysts ◽

10.3390/catal11030290 ◽

2021 ◽

Vol 11 (3) ◽

pp. 290

Author(s):

Tim Karsten ◽

Vesna Middelkoop ◽

Dorota Matras ◽

Antonis Vamvakeros ◽

Stephen Poulston ◽

...

Keyword(s):

Oxidative Coupling ◽

Oxidative Coupling Of Methane ◽

Operating Conditions ◽

Homogeneous Distribution ◽

Silica Support ◽

X Ray Diffraction ◽

Cross Sectional ◽

X Ray ◽

Multi Scale ◽

3D Printed

This work presents multi-scale approaches to investigate 3D printed structured Mn–Na–W/SiO2 catalysts used for the oxidative coupling of methane (OCM) reaction. The performance of the 3D printed catalysts has been compared to their conventional analogues, packed beds of pellets and powder. The physicochemical properties of the 3D printed catalysts were investigated using scanning electron microscopy, nitrogen adsorption and X-ray diffraction (XRD). Performance and durability tests of the 3D printed catalysts were conducted in the laboratory and in a miniplant under real reaction conditions. In addition, synchrotron-based X-ray diffraction computed tomography technique (XRD-CT) was employed to obtain cross sectional maps at three different positions selected within the 3D printed catalyst body during the OCM reaction. The maps revealed the evolution of catalyst active phases and silica support on spatial and temporal scales within the interiors of the 3D printed catalyst under operating conditions. These results were accompanied with SEM-EDS analysis that indicated a homogeneous distribution of the active catalyst particles across the silica support.

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Adsorption Characteristics of Modified MiL-101(Cr) for Gas (Mainly CH4) Storage Applications

Volume 6B: Energy ◽

10.1115/imece2015-50751 ◽

2015 ◽

Cited By ~ 1

Author(s):

How Wei Benjamin Teo ◽

Anutosh Chakraborty ◽

Kim Tiow Ooi

Keyword(s):

Natural Gas ◽

X Ray Diffraction ◽

Uptake Capacity ◽

N2 Adsorption ◽

Thermo Gravimetric ◽

X Ray ◽

Thermo Gravimetric Analyzer ◽

Metal Organic ◽

Ch4 Uptake

As promising material for gas storage applications, MIL-101(Cr) can further be modified by doping with alkali metal (Li+, Na+, K+) ions. However, the doping concentration should be optimized below 10% to improve the methane adsorption. This article presents (i) the synthesis of MIL-101 (Cr) Metal Organic Frameworks, (ii) the characterization of the proposed doped adsorbent materials by X-ray Diffraction, Scanning Electron Microscopy, N2 Adsorption, Thermo-Gravimetric Analyzer, and (iii) the measurements of methane uptakes for the temperatures ranging from 125 K to 303 K and pressures up to 10 bar. It is found that the Na+ doped MIL-101(Cr) exhibits CH4 uptake capacity of (i) 295 cm3/cm3 at 10 bar and 160 K and (ii) 95 cm3/cm3 at 10 bar at 298 K. This information is important to design adsorbed natural gas (ANG) storage tank under ANG-LNG (liquefied natural gas) coupling conditions.

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Modified Lime Binders for Restoration Work

Buildings ◽

10.3390/buildings11030098 ◽

2021 ◽

Vol 11 (3) ◽

pp. 98

Author(s):

Valentina Loganina ◽

Kristina Sergeeva ◽

Roman Fediuk ◽

Sergey Klyuev ◽

Nikolai Vatin ◽

...

Keyword(s):

Storage Time ◽

Infrared Spectrometry ◽

X Ray Diffraction ◽

X Ray ◽

Gain Rate ◽

Calcium Silicate Hydrates ◽

Restoration Work ◽

Weather Resistance ◽

Kinetics Of ◽

Mixing Water

Lime mixes are the primary material for restoration work in historic buildings. The research object of this study is modifying lime binders with specially synthesized calcium silicate hydrates (CSHs). This study aimed to improve lime render mixes’ weather resistance. The following factors were considered: the density of the liquid glass, the amount of the precipitating additive, the rate of introduction of the precipitating additive, the drying mode of the precipitate, and the storage time of the precipitate. The research methods were X-ray diffraction analysis, differential thermal analysis, Fourier transform infrared spectrometry, and optical and electron microscopy. It was revealed that lime compositions with CSH have a higher strength gain rate than the control compositions. A mathematical model of the kinetics of hardening a lime composite based on a binder filled with CSH was obtained. The regularities of the change in the lime composite’s strength depending on the filler grinding’s fineness, its content, and the amount of mixing water have been established. It was revealed that the introduction of CSH into the lime composition increases the weather resistance of facade lime mixtures by reducing the porosity and increasing the volume of closed pores of the composite.

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