Treatment of European beech with a new wood fire retardant agent based on in situ deposition of calcium oxalate

Holzforschung ◽  
2019 ◽  
Vol 73 (11) ◽  
pp. 1047-1050 ◽  
Author(s):  
Tom Franke ◽  
Thomas Volkmer
Keyword(s):  
Calcium Oxalate ◽  
Fire Retardant ◽  
European Beech ◽  
Potassium Oxalate ◽  
Agent Based ◽  
Weight Percentage ◽  
In Situ Deposition ◽  
Wood Fire ◽  
Weight Percentage Gain

Abstract European beech (Fagus sylvatica L.) was impregnated in a two-step process with aqueous solutions of potassium oxalate and calcium chloride successively. These compounds are intended to react in situ to the water-insoluble salt calcium oxalate and the reaction by-product potassium chloride. In order to assess the treatability, the solid uptake after the first impregnation and after the treatment was examined. The fixation of the precipitated salts was measured in leaching tests according to the European standard EN 84. The reaction to fire of mineralized beech was tested following the standard ISO 11925-2. A weight percentage gain of appr. 35% indicates a sucessful treatment of the beech with the mineralization agents. The weight percentage gain after leaching indicates a sufficient fixation of calcium oxalate in the wood. Furthermore, results from flammability tests indicate improved fire resistance due to the mineralization.

Mineralization treatment of European oak heartwood with calcium oxalate for improved fire retardancy

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tom Franke ◽  
Thomas Volkmer
Keyword(s):  
Calcium Oxalate ◽  
Fire Retardant ◽  
Calcium Acetate ◽  
Fire Retardancy ◽  
Potassium Oxalate ◽  
Aqueous Salt Solutions ◽  
Fire Retardant Properties ◽  
European Oak ◽  
Source Test

Abstract Within the focus to apply substances for wood protections, here fire retardants, with low hazardous and low environmental impact is of interest. Additionally, European oak is an attractive species for various interior and exterior applications. However, oak is classified as very heavily treatable and thus impregnation is challenging. However, the focus of this study was to treat European oak with a new fire retardant based on an in-situ calcium oxalate deposition. Thin oak specimens with a thickness of 4 mm were investigated with two various formulations of aqueous salt solutions (potassium oxalate and calcium chloride, and potassium oxalate and calcium acetate) to obtain an in-situ mineralization of calcium oxalate during a two-step impregnation process. The uptake, the distribution, and the penetration of the salts for both applied formulations were investigated. Additionally, fire retardant properties were investigated in a single flame source test. It could be demonstrated that an acceptable degree of treatability was achieved for both applied formulations. The fire retardancy of the so mineralized material was clearly improved. Synergetic effects which might be caused by the reaction side products of the various formulations were found to be neglectable.

In situ deposition of magnetic nanoparticles on glass mat using plasma sputtering method

2021 ◽  
pp. 1-11
Author(s):  
Sheila Shahidi ◽  
Sanaz Dalalsharifi ◽  
Mahmood Ghoranneviss ◽  
Rattanaphol Mongkholrattanasit
Keyword(s):  
Magnetic Nanoparticles ◽  
Plasma Sputtering ◽  
In Situ Deposition ◽  
Glass Mat

scholarly journals A new hypothesis for the origin of Amazonian Dark Earths

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lucas C. R. Silva ◽  
Rodrigo Studart Corrêa ◽  
Jamie L. Wright ◽  
Barbara Bomfim ◽  
Lauren Hendricks ◽  
...  
Keyword(s):  
Indigenous Peoples ◽  
Sustainable Use ◽  
Mineral Elements ◽  
High Fertility ◽  
Natural Processes ◽  
Plant Cultivation ◽  
In Situ Deposition ◽  
Amazonian Dark Earths ◽  
Landscape Formation

AbstractAmazonian Dark Earths (ADEs) are unusually fertile soils characterised by elevated concentrations of microscopic charcoal particles, which confer their distinctive colouration. Frequent occurrences of pre-Columbian artefacts at ADE sites led to their ubiquitous classification as Anthrosols (soils of anthropic origin). However, it remains unclear how indigenous peoples created areas of high fertility in one of the most nutrient-impoverished environments on Earth. Here, we report new data from a well-studied ADE site in the Brazilian Amazon, which compel us to reconsider its anthropic origin. The amounts of phosphorus and calcium—two of the least abundant macronutrients in the region—are orders of magnitude higher in ADE profiles than in the surrounding soil. The elevated levels of phosphorus and calcium, which are often interpreted as evidence of human activity at other sites, correlate spatially with trace elements that indicate exogenous mineral sources rather than in situ deposition. Stable isotope ratios of neodymium, strontium, and radiocarbon activity of microcharcoal particles also indicate exogenous inputs from alluvial deposition of carbon and mineral elements to ADE profiles,  beginning several thousands of years before the earliest evidence of soil management for plant cultivation in the region. Our data suggest that indigenous peoples harnessed natural processes of landscape formation, which led to the unique properties of ADEs, but were not responsible for their genesis. If corroborated elsewhere, this hypothesis would transform our understanding of human influence in Amazonia, opening new frontiers for the sustainable use of tropical landscapes going forward.

In situ deposition of ErNi2B2C films by pulsed laser ablation technique

1998 ◽  
Vol 299 (1-2) ◽  
pp. 15-22 ◽  
Author(s):  
A Canesi ◽  
M.R Cimberle ◽  
C Ferdeghini ◽  
A Diaspro ◽  
P Guasconi ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Ablation Technique ◽  
In Situ Deposition ◽  
Laser Ablation Technique

Molecular modulation of calcium oxalate crystallization

2006 ◽  
Vol 291 (6) ◽  
pp. F1123-F1132 ◽  
Author(s):  
James J. De Yoreo ◽  
S. Roger Qiu ◽  
John R. Hoyer
Keyword(s):  
Molecular Modeling ◽  
Calcium Oxalate ◽  
Stone Formation ◽  
Energy Levels ◽  
Critical Role ◽  
Specific Interactions ◽  
Crystal Surfaces ◽  
Site Specific

Calcium oxalate monohydrate (COM) is the primary constituent of the majority of renal stones. Osteopontin (OPN), an aspartic acid-rich urinary protein, and citrate, a much smaller molecule, are potent inhibitors of COM crystallization at levels present in normal urine. Current concepts of the role of site-specific interactions in crystallization derived from studies of biomineralization are reviewed to provide a context for understanding modulation of COM growth at a molecular level. Results from in situ atomic force microscopy (AFM) analyses of the effects of citrate and OPN on growth verified the critical role of site-specific interactions between these growth modulators and individual steps on COM crystal surfaces. Molecular modeling investigations of interactions of citrate with steps and faces on COM crystal surfaces provided links between the stereochemistry of interaction and the binding energy levels that underlie mechanisms of growth modification and changes in overall crystal morphology. The combination of in situ AFM and molecular modeling provides new knowledge that will aid rationale design of therapeutic agents for inhibition of stone formation.

Properties of Thin SiO2 Films with In-Situ Deposition of Poly Si Electrodes

1989 ◽  
Vol 146 ◽  
Author(s):  
Paihung Pan ◽  
Ahmad Kermani ◽  
Wayne Berry ◽  
Jimmy Liao
Keyword(s):  
Electrical Properties ◽  
Breakdown Strength ◽  
Chemical Vapor ◽  
Interface State ◽  
State Density ◽  
In Situ Deposition ◽  
Different Temperatures ◽  
Flatband Voltage ◽  
Si Films

ABSTRACTElectrical properties of thin (12 nm) SiO2 films with and without in-situ deposited poly Si electrodes have been studied. Thin SiO2 films were grown by the rapid thermal oxidation (RTO) process and the poly Si films were deposited by the rapid thermal chemical vapor deposition (RTCVD) technique at 675°C and 800°C. Good electrical properties were observed for SiO2 films with thin in-situ poly Si deposition; the flatband voltage was ∼ -0.86 V, the interface state density was < 2 × 1010/cm2/eV, and breakdown strength was > 10 MV/cm. The properties of RTCVD poly Si were also studied. The grain size was 10-60 rim before anneal and was 50-120 rim after anneal. Voids were found in thin (< 70 nm) RTCVD poly Si films. No difference in either SiO2 properties or poly Si properties was observed for poly Si films deposited at different temperatures.

In-situ deposition of superconducting YBCO films on Si with ceramic buffer layers

1993 ◽  
Vol 1 (3-6) ◽  
pp. 815-826 ◽  
Author(s):  
J.Y. Juang ◽  
K.H. Wu ◽  
T.C. Lai ◽  
M.H. Lee ◽  
M.C. Hseih ◽  
...  
Keyword(s):  
Buffer Layers ◽  
Ybco Films ◽  
In Situ Deposition
Sign in / Sign up

Export Citation Format

Share Document