A Novel Method to Quantify Dentine Tubule Occlusion Applied to in situ Model Samples

AbstractThe conservation of iron objects exposed to marine aerosol is threatened by the formation of akaganeite, a highly unstable Cl-bearing corrosion phase. As akaganeite formation is responsible of the exfoliation of the rust layer, chlorides trigger a cyclic alteration phenomenon that often ends with the total consumption of the iron core. To prevent this degradation process, movable iron elements (e.g. archaeometallurgical artefacts) are generally immersed in alkaline dechlorination baths. Aiming to transfer this successful method to the treatment of immovable iron objects, we propose the in-situ application of alkaline solutions through the use of highly absorbent wraps. As first step of this novel research line, the present work defines the best desalination solution to be used and optimizes its extraction yield. After literature review, a screening experimental design was performed to understand the single and synergic effects of common additives used for NaOH baths. Once the most effective variables were selected, an optimization design was carried out to determine the optimal conditions to be set during treatment. According to the experimental work here presented, the use of 0.7 M NaOH solutions applied at high temperatures (above 50 °C) is recommended. Indeed, these conditions enhance chloride extraction and iron leaching inhibition, while promoting corrosion stabilization.

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Using Sentinel-2 Images to Estimate Topography, Tidal-Stage Lags and Exposure Periods over Large Intertidal Areas

Remote Sensing ◽

10.3390/rs13020320 ◽

2021 ◽

Vol 13 (2) ◽

pp. 320

Author(s):

José P. Granadeiro ◽

João Belo ◽

Mohamed Henriques ◽

João Catalão ◽

Teresa Catry

Keyword(s):

Large Scale ◽

Exposure Period ◽

Intertidal Area ◽

Digital Elevation ◽

Geographical Bias ◽

Novel Method ◽

Tidal Stage ◽

Sentinel 2

Intertidal areas provide key ecosystem services but are declining worldwide. Digital elevation models (DEMs) are important tools to monitor the evolution of such areas. In this study, we aim at (i) estimating the intertidal topography based on an established pixel-wise algorithm, from Sentinel-2 MultiSpectral Instrument scenes, (ii) implementing a set of procedures to improve the quality of such estimation, and (iii) estimating the exposure period of the intertidal area of the Bijagós Archipelago, Guinea-Bissau. We first propose a four-parameter logistic regression to estimate intertidal topography. Afterwards, we develop a novel method to estimate tide-stage lags in the area covered by a Sentinel-2 scene to correct for geographical bias in topographic estimation resulting from differences in water height within each image. Our method searches for the minimum differences in height estimates obtained from rising and ebbing tides separately, enabling the estimation of cotidal lines. Tidal-stage differences estimated closely matched those published by official authorities. We re-estimated pixel heights from which we produced a model of intertidal exposure period. We obtained a high correlation between predicted and in-situ measurements of exposure period. We highlight the importance of remote sensing to deliver large-scale intertidal DEM and tide-stage data, with relevance for coastal safety, ecology and biodiversity conservation.

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A novel method for in situ stabilization of calcium arsenic residues via yukonite formation

The Science of The Total Environment ◽

10.1016/j.scitotenv.2022.153090 ◽

2022 ◽

pp. 153090

Author(s):

Yumeng Wang ◽

Shaofeng Wang ◽

Yu Song ◽

Peiwen Zhang ◽

Xu Ma ◽

...

Keyword(s):

In Situ Stabilization ◽

Novel Method

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High Shear in Situ Exfoliation of 2D Gallium Oxide Sheets from Centrifugally Derived Thin Films of Liquid Gallium

10.26434/chemrxiv.14571573 ◽

2021 ◽

Author(s):

Kasturi Vimalanathan ◽

Timotheos Palmer ◽

Zoe Gardner ◽

Irene Ling ◽

Soraya Rahpeima ◽

...

Keyword(s):

Gallium Oxide ◽

High Mass ◽

Liquid Gallium ◽

The Novel ◽

Continuous Flow Condition ◽

Novel Method ◽

Hydrogen Evolution Reactions ◽

Insulating Properties ◽

Microfluidics Platform

Herein, we have explored the use of a microfluidics platform for the exfoliation and oxidation of liquid gallium into ultrathin sheets of gallium oxide under continuous flow condition. The novel method developed here takes advantage of the high mass transfer in liquids and has the potential for creating high yielding thin sheets of oxidised gallium with insulating properties as well as acts as an active catalyst in hydrogen evolution reactions. This highlights the potential utility of the sheets as an alternative to the expensive and scarce noble metal based electrocatalysts

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Nutrient and hormone levels in Douglas-fir corrosion cavities, megagametophytes, and embryos during embryony

Canadian Journal of Forest Research ◽

10.1139/x05-173 ◽

2005 ◽

Vol 35 (10) ◽

pp. 2447-2456 ◽

Cited By ~ 18

Author(s):

John G Carman ◽

Gordon Reese ◽

Rodney J Fuller ◽

Timnit Ghermay ◽

Roger Timmis

Keyword(s):

Pseudotsuga Menziesii ◽

Dry Mass ◽

Douglas Fir ◽

Chemical Analyses ◽

Dynamic Changes ◽

Hormone Levels ◽

Corrosion Cavity ◽

Novel Method ◽

Indole 3 Acetic Acid

Gymnospermous embryos are nourished by fluids secreted from the megagametophyte. During early embryony, these fluids occupy the newly formed corrosion cavity. We describe a novel method for extracting corrosion cavity fluid and provide chemical analyses based on extractions from approximately 120 000 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) megagametophytes. Levels of potassium, phosphorus, calcium, zinc, and iron were higher in corrosion cavity fluid than in whole tissue, but levels of sulphur and manganese were lower. Levels of cyclitols, sucrose equivalents, erythrose, and arabinose were many-fold higher in corrosion cavity fluid than in whole tissues. Ala, Ser, Arg, Glx, and NH3 exceeded 80 mmol/kg dry mass in corrosion cavity fluid. These levels were about 100-fold higher than those found in whole tissues. During early embryony, hormone levels in corrosion cavity fluid were higher than levels observed in whole megagametophytes by 120-fold for indole-3-acetic acid, 53-fold for abscisic acid, and 8- to 10-fold for cytokinins. Nutrient and hormone levels tended to be much higher in the corrosion cavity fluid than would have been predicted based on whole-tissue analyses. Dynamic changes in nutrient and hormone levels occurred over time in the corrosion cavity, and these changes may normalize embryony in situ.

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Poly(catecholamine) Coating and Biofunctionalization of CsPbBr3 Microcrystals

10.26434/chemrxiv.14049710.v2 ◽

2021 ◽

Author(s):

Sangyeon Cho ◽

Seok-Hyun Yun

Keyword(s):

Lipid Bilayers ◽

Environmental Stability ◽

Live Cells ◽

Functional Coatings ◽

Common Strategy ◽

Novel Method ◽

Halide Perovskites ◽

The Stability ◽

New Applications

Lead halide perovskites (LHP) microcrystals are promising materials for various optoelectronic applications. Surface coating on particles is a common strategy to improve their functionality and environmental stability, but LHP is not amenable to most coating chemistries because of its intrinsic weakness against polar solvents. Here, we describe a novel method of synthesizing LHP microcrystals in a super-saturated polar solvent using sonochemistry and applying various functional coatings on individual microcrystals in situ. We synthesize cesium lead bromine perovskite (CsPbBr3) microparticles capped with organic poly-norepinephrine (pNE) layers. The catechol group of pNE coordinates to bromine-deficient lead atoms, forming a defect-passivating and diffusion-blocking shell. The pNE layer enhances the stability of CsPbBr3 in water by 2,000-folds, enabling bright luminescence and lasing from single microcrystals in water. Furthermore, the pNE shell permits biofunctionalization with proteins, small molecules, and lipid bilayers. Luminescence from CsPbBr3 microcrystals is sustained in water over 1 hour and observed in live cells. The functionalization method may enable new applications of LHP particles in water-rich environments.

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