scholarly journals Smoke Hazard Assessment of Cypress Wood Coated with Boron/Silicon Sol Compounds

2020 ◽  
Vol 34 (1) ◽  
pp. 1-10
Author(s):  
Eui Jin ◽  
Yeong-Jin Chung
Keyword(s):  
Boric Acid ◽  
Performance Index ◽  
Boronic Acid ◽  
Phenylboronic Acid ◽  
Growth Index ◽  
Fire Risk ◽  
Fire Intensity ◽  
Boronic Acid Derivatives ◽  
Silicon Sol ◽  
External Heat Flux

In this study, boron/silicon sol compounds were applied to wood for construction and durable materials, and fire risks were investigated in terms of smoke performance index (SPI), smoke growth index (SGI), and smoke intensity (SI). The compound was synthesized by reacting tetraethoxyorthosilicate with boric acid and boronic acid derivatives. Smoke characteristics were investigated using a cone calorimeter (ISO 5660-1) equipment for cypress wood. The fire intensity fixed the external heat flux at 50 kW/m<sup>2</sup>. The smoke performance index measured after the combustion reaction increased between 13.4% and 126.7% compared with cypress wood. The fire risk due to the smoke performance index decreased in the order of cypress, phenylboronic acid/silicon sol (PBA/Si), (2-methylpropyl) boronic acid/silicon sol (IBBA/Si), boric acid/silicon sol (BA/Si). The smoke growth index decreased between 12.0% and 57.5% compared to the base specimen. The risk of fire caused by the smoke growth index decreased in the order of cypress, PBA/Si, IBBA/Si, BA/Si. The fire risk due to smoke intensity decreased between 3.2% and 57.8%, and in the order of cypress, PBA/Si, IBBA/Si, BA/Si. CO<sub>peak</sub> concentrations ranged between 85 and 93 ppm, and decreased between 37% and 43% compared to the base specimen. A comprehensive assessment of the fire risk on smoke hazards decreased in the order of cypress, PBA/Si, IBBA/Si, BA/Si.

scholarly journals Rating Evaluation of Fire Risk Associated with Plastics

2021 ◽  
Vol 35 (2) ◽  
pp. 9-15
Author(s):  
Ji Sun You ◽  
Yeong-jin Chung
Keyword(s):  
Performance Index ◽  
Fire Hazard ◽  
Growth Index ◽  
Fire Risk ◽  
Fire Performance ◽  
Fire Growth ◽  
Glass Fiber Reinforced Plastic ◽  
Fiber Reinforced Plastic ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic

In this study, plastics such as glass fiber reinforced plastic (GFRP), polystyrene (PS), polycarbonate (PC), polypropylene (PP), polyvinyl chloride (PVC) were selected, and the fire risk associated with them was investigated using a cone calorimeter, as per ISO 5660-1. These values were measured to comprehensively predict the fire risk by Chung’s equations- Ⅱ. Standard materials (PMMA) were used to standardize the fire hazard assessment, and the fire risk was classified and evaluated by new Chung’s equations-III and Chung’s equation-IV. The fire performance index-II of Chung’s equations-Ⅱ showed that PVC had the highest FPI-II of 32.04 s<sup>2</sup>/kW, whereas PS had the lowest FPI-Ⅱ of 0.07 s<sup>2</sup>/kW. From the viewpoint of FGI-Ⅱ, the lowest fire growth index-Ⅱ was 0.09 kW/s<sup>2</sup> for PVC, and the highest fire growth index-Ⅱ for PS was 3.41 kW/s<sup>2</sup>. The FPI-Ⅲ of Chung’s equations-Ⅲ had the lowest fire performance index-Ⅲ for PS (0.02) and highest fire performance index-Ⅲ for PVC (89). The FGI-Ⅲ had the highest fire growth index-Ⅲ of 20.1, and PS and PVC were found to be the safest materials with an FGI of 0.5. The FRI-Ⅳ of Chung’s equation-Ⅳ was in the following order: PS (100.5) ≫ PP (2.43) > PC (1.12) > PMMA (1.0) > FRP (0.19) > PVC (0.01). Therefore, it was concluded that the fire risk associated with PVC is lowest, whereas that associated with PS is highest.

Fire risk assessment of cypress wood coated with metal oxide and metal silicate flame retardant using cone calorimeter

2020 ◽  
Vol 38 (6) ◽  
pp. 504-521
Author(s):  
Eui Jin ◽  
Yeong-Jin Chung
Keyword(s):  
Metal Oxide ◽  
Performance Index ◽  
Cone Calorimeter ◽  
Flame Retardants ◽  
Growth Index ◽  
Fire Risk ◽  
Silicon Compound ◽  
Fire Performance ◽  
Metal Silicate ◽  
Fire Scenarios

This study investigated the fire risk properties of cypress wood for the construction of interiors, especially focusing on heat and smoke hazard properties in fire scenarios. Fire risk characteristics were measured using a cone calorimeter (ISO 5660-1). The external heat flux was maintained at 50 kW/m2. The flame retardants used were metal oxide and metal silicate; they were mixed with a water glass solution. Flame retardants and the silicon compound were dispersed in a concentration of 20 wt% versus 80 wt%, respectively, during 24 h using a magnetic stirrer. The fire performance indexes of the specimens increased by 3–16 times, compared with uncoated specimen and the fire growth index of the specimens increased by 70%–92%. The smoke performance index of the specimens increased by 9–66 times, compared with uncoated specimens. The smoke risk as shown by the smoke performance index increased in the following order: SnO < mica < Co3O4 < ZrSiO4 < cypress. The smoke growth index decreased from 93% to 98%, compared with uncoated wood. The smoke risk due to smoke growth index increased in the following order: SnO < mica < ZrSiO4≈ Co3O4 < cypress. The smoke intensity decreased from a minimum of 85% to a maximum of 99%, compared with uncoated wood. The concentration of CO gas generated after combustion was decreased by 24%–67%. They increased in the following order: mica ≈ ZrSiO4 < SnO < Co3O4 < cypress. A comprehensive assessment of fire performance shows that flame retardants decreased heat hazards, smoke hazards, and CO toxicity.

Arylboronic Acids in Self-condensation of Glucosamines Forming Deoxyfructosazine, Catalysts or Reagents?

2019 ◽  
Author(s):  
Meifeng Wang ◽  
Gan Zhu ◽  
Yiqun Li ◽  
Liuqun Gu
Keyword(s):  
Molecular Recognition ◽  
Boric Acid ◽  
Boronic Acid ◽  
Catalytic Mechanism ◽  
Organic Transformations ◽  
Food Industries ◽  
Arylboronic Acids ◽  
Excess Amount ◽  
Phenyl Boronic Acid ◽  
Boron Acid

Arylboronic acids were widely used as efficient catalysts in direct amide formation and other organic transformations. Surprisingly, reports on their use as catalysts in carbohydrates synthesis are very rare even though boron acid-diol complexation was extensively investigated in molecular recognition for saccharides and so on. Here we developed an efficient arylboronic acids catalyzed dimerization of glucosamines forming deoxyfructosazine which is important compound in pharmaceutical and food industries, against a commonly held belief that excess amount of phenyl boronic acid (or boric acid) is a must. A catalytic mechanism was also proposed and arylboronic acids instead of their boronates was identified as catalysts.

Synthesis of Sugar–Boronic Acid Derivatives: A Class of Potential Agents for Boron Neutron Capture Therapy

2017 ◽  
Vol 19 (7) ◽  
pp. 1678-1681 ◽  
Author(s):  
Daniela Imperio ◽  
Erika Del Grosso ◽  
Silvia Fallarini ◽  
Grazia Lombardi ◽  
Luigi Panza
Keyword(s):  
Boron Neutron Capture Therapy ◽  
Neutron Capture ◽  
Boronic Acid ◽  
Neutron Capture Therapy ◽  
Boron Neutron Capture ◽  
Boronic Acid Derivatives

Recognition and sensing of various species using boronic acid derivatives

2012 ◽  
Vol 48 (48) ◽  
pp. 5956 ◽  
Author(s):  
Zhiqian Guo ◽  
Injae Shin ◽  
Juyoung Yoon
Keyword(s):  
Boronic Acid ◽  
Boronic Acid Derivatives

scholarly journals COMPORTAMENTO DO FOGO EM QUEIMAS CONTROLADAS DE VEGETAÇÃO DE ESTEPE NO MUNICÍPIO DE PALMEIRA, PARANÁ, BRASIL

FLORESTA ◽  
2013 ◽  
Vol 43 (4) ◽  
pp. 557
Author(s):  
Celso Darci Seger ◽  
Antonio Carlos Batista ◽  
Alexandre França Tetto ◽  
Ronaldo Viana Soares
Keyword(s):  
Fire Behavior ◽  
Fire Risk ◽  
Fire Spread ◽  
Flame Height ◽  
Fire Intensity ◽  
Average Moisture Content ◽  
Fuel Loading ◽  
Prescribed Burns ◽  
Controlled Burning ◽  
Heat Released

As queimas controladas constituem práticas de manejo utilizadas em diferentes tipos de vegetação e difundidas em vários países. No entanto, para a realização de tais práticas com segurança e eficiência é fundamental o conhecimento do comportamento do fogo. O objetivo desse trabalho foi caracterizar o comportamento do fogo em queimas controladas de vegetação Estepe Gramíneo-Lenhosa no estado do Paraná. Para isso, foi instalado um experimento no município de Palmeira, onde 20 parcelas foram queimadas, sendo metade a favor e metade contra o vento. A carga de material combustível fino estimada foi de 2,26 kg.m-2, com teor médio de umidade de 50,45%. A quantidade de material consumido pela queima foi de 1,76 kg.m-2, com uma eficiência média de queima de 76,86%. As médias obtidas, a favor e contra o vento, foram respectivamente: velocidade de propagação do fogo de 0,049 e 0,012 m.s-1, altura das chamas de 1,34 e 0,843 m, intensidade do fogo de 210,53 e 50,68 kcal.m-1.s-1 e calor liberado de 4.067,19 e 4.508,92 kcal.m-2. Os resultados permitiram concluir que as queimas controladas em vegetação de campos naturais, realizadas dentro dos critérios estabelecidos de planos de queima, são viáveis e seguras sob o ponto de vista de perigo de incêndios.Palavras chave: Queima prescrita; material combustível; intensidade do fogo; perigo de incêndios. AbstractFire behavior of prescribed burns in grassland on Palmeira county, Paraná, Brazil. The prescribed burns are practices of management used in different types of vegetation and widespread in several countries. However, to carry out such practices safely and effectively is fundamental knowledge of fire behavior. The aim of this study was to characterize the fire behavior in controlled burning of grassland vegetation in Paraná state. For this, an experiment was conducted in Palmeira County, where 20 plots were burned, half in favor and half against the wind. The estimated fine fuel loading was 2.26 kg.m-2, with average moisture content of 50.45%. The fuel consumption by burning was 1.76 kg.m-2 with an average efficiency of burning of 76.86%. The averages, for and against the wind, were: speed of fire spread of 0.049 and 0.012 m.s-1, the flame height of 1.34 m and 0.843, fire intensity of 210.53 and 50.68 kcal.m-1.s-1 and heat released from 4,067.19 and 4,508.92 kcal.m-2. The results show that the controlled burnings of grasslands vegetation, carried out within the established criteria burning plans are feasible and safe from the aspect of fire danger.Keywords: Prescribed burns; fuel loading; fire intensity; fire risk.

The modern role of boron as a 'magic element' in biomedical science: Chemistry perspective

2021 ◽  
Author(s):  
SAURAV CHATTERJEE ◽  
NITESH MANI Mani TRIPATHI ◽  
Anupam Bandyopadhyay
Keyword(s):  
Drug Discovery ◽  
Boronic Acid ◽  
Toxic Element ◽  
Biomedical Science ◽  
Boronic Acid Derivatives

The boron was misconstrued as a toxic element for animals, which retarded the growth of boron-containing drug discovery in the last century. Nevertheless, modern applications of boronic acid derivatives are...

scholarly journals Rapid approach to complex boronic acids

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw4607 ◽  
Author(s):  
Constantinos G. Neochoritis ◽  
Shabnam Shaabani ◽  
Maryam Ahmadianmoghaddam ◽  
Tryfon Zarganes-Tzitzikas ◽  
Li Gao ◽  
...  
Keyword(s):  
Small Molecules ◽  
Boronic Acid ◽  
Multicomponent Reactions ◽  
Chemical Space ◽  
Building Blocks ◽  
Acid Synthesis ◽  
Success Rates ◽  
Boronic Acid Derivatives ◽  
Low Coverage ◽  
Target Synthesis

The compatibility of free boronic acid building blocks in multicomponent reactions to readily create large libraries of diverse and complex small molecules was investigated. Traditionally, boronic acid synthesis is sequential, synthetically demanding, and time-consuming, which leads to high target synthesis times and low coverage of the boronic acid chemical space. We have performed the synthesis of large libraries of boronic acid derivatives based on multiple chemistries and building blocks using acoustic dispensing technology. The synthesis was performed on a nanomole scale with high synthesis success rates. The discovery of a protease inhibitor underscores the usefulness of the approach. Our acoustic dispensing–enabled chemistry paves the way to highly accelerated synthesis and miniaturized reaction scouting, allowing access to unprecedented boronic acid libraries.

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