scholarly journals Study on Spontaneous Combustion Risk of Coin Plating Experiment Residue

2020 ◽  
Vol 20 (2) ◽  
pp. 89-94
Author(s):  
Gi-Bong Ko ◽  
Si-Young Lee ◽  
Hyeong-Do Kim
Keyword(s):  
Aqueous Solution ◽  
Sodium Hydroxide ◽  
Fire Safety ◽  
Spontaneous Combustion ◽  
Waste Incinerator ◽  
Safety Education ◽  
Fire Extinguishing ◽  
Toilet Paper ◽  
Fire Experiment ◽  
Science Laboratories

This study examines the risk of spontaneous combustion caused by the residue of the coin plating experiment. In this study, three cases of recent fires due to the unauthorized disposal of the residues left from coin plating experiments in middle and high schools of the Gangwon-do Province (2017～2018) were analyzed and an experiment to recreate the fire was conducted. As a result of the analysis of the three cases of school fires, it was shown that the students who participated in the coin plating experiment wiped the aqueous solution that spilled onto the table during the procedure as well as the residue of the solution inside the beaker with a tissue and disposed of it on the classroom floor or in a plastic trash can along with the coin that was used. If short, 1 h and 18 min, if long, 8 h and 15 min after the tissues with the residues were thrown away in the trash can, a fire broke out. In addition, when the fire experiment was recreated, in a state where 5 g of sodium hydroxide and 5 g of powdered zinc were partially overlapped, 0.25 ml of water was added. After 20 min since the start of the experiment, a fire occurred as the temperature rose to 549 ℃. In particular, when the coin experiment residue was put on toilet paper and dried for 5 min using a hair dryer, a fire occurred as flames started to appear from the residue. Therefore, in order to prevent fires, it is safe to dispose of the residues after conducting the coin plating experiments in waste incinerator machines. Fire safety education must also be enforced upon teachers who are in charge of instructing chemical experiments at school, and science laboratories must be equipped with automatic fire extinguishing facilities, e.g., trash cans that are placed in the classrooms must be made of steel to ensure complete safety.

Modification of activated carbon using sodium acetate and its regeneration using sodium hydroxide for the adsorption of copper from aqueous solution

Carbon ◽  
2007 ◽  
Vol 45 (5) ◽  
pp. 1081-1084 ◽  
Author(s):  
Dan Mugisidi ◽  
Aria Ranaldo ◽  
Johny W. Soedarsono ◽  
Muhammad Hikam
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Sodium Hydroxide ◽  
Sodium Acetate

The Pre-Controlling Technology of Spontaneous Combustion in Gutter-Up Gob for Fully Mechanized Top-Coal Caving Face

2013 ◽  
Vol 634-638 ◽  
pp. 3688-3695 ◽  
Author(s):  
Yang Xiao ◽  
Shu Gang Li ◽  
Jun Deng ◽  
Xu Wang
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Fly Ash ◽  
Coal Mining ◽  
Spontaneous Combustion ◽  
Good Effect ◽  
Air Leakage ◽  
Coal Spontaneous Combustion ◽  
Liquid Carbon ◽  
Fire Extinguishing

In China, as popularizing the technology of fully mechanized top-coal mining and increasing the strength and depth of mining, the gutter-up gob can be formed. But the work of fire preventing and extinguishing for its coal spontaneous combustion is more complexity and difficulty. In this paper, based on geology parameters and mining practice for 93up12 fully mechanized top-coal caving face in Nantun coalmine, the form and character of gutter-up gob are analyzed. According to the hidden danger of high temperature for spontaneous combustion in the gob, we adopt the comprehension technologies of fire extinguishing and preventing which include sealing air-leakage, grouting, and injecting compound gel with fly-ash, foam of retarding oxidation, liquid carbon dioxide, and gas of nitrogen. By putting in practice the pre-controlling technology in gutter-up gob and monitoring data of target gases, it obtains a good effect and ensures the safety in production of the fully-mechanized top-coal caving face.

Studies on Grafting Copolymerization of Lactic Acid onto Cornstarch Catalyzed with Sodium Hydroxide

2011 ◽  
Vol 233-235 ◽  
pp. 1906-1910
Author(s):  
Ying Mo Hu ◽  
Qing Ling Wang ◽  
Jian Hua Zhu ◽  
Yang Liu ◽  
Xue Yang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Lactic Acid ◽  
Sodium Hydroxide ◽  
Convenient Method ◽  
Graft Copolymerization ◽  
Good Adhesion ◽  
Acid Copolymer ◽  
Grafting Copolymerization ◽  
Grafting Degree

A convenient method to synthesize starch/lactic acid copolymer was studied in this work. Copolymer of starch graft with lactic acid (LA) was directly prepared by reaction of cornstarch with lactic acid in sodium hydroxide (NaOH) aqueous solution as a catalyst. The product was characterized by IR and WAXD, and the good adhesion between the two components has been observed by SEM. The results showed that the highest grafting degree could reach 33.60% when the graft copolymerization was carried in 0.40 mol·L-1 NaOH aqueous for 9 h at 90°C with the 1: 5~6 ratio of starch and lactic acid.

Behaviour of scleroglucan in aqueous solution containing sodium hydroxide

1987 ◽  
Vol 9 (3) ◽  
pp. 153-157 ◽  
Author(s):  
Shuquin Bo ◽  
Michel Milas ◽  
Marguerite Rinaudo
Keyword(s):  
Aqueous Solution ◽  
Sodium Hydroxide

Synthesis and bioactivity of novel C2-glycosyl triazole derivatives as acetylcholinesterase inhibitors

2017 ◽  
Vol 23 (3) ◽  
pp. 231-236 ◽  
Author(s):  
Long Yin ◽  
Lei Wang ◽  
Xiu-Jian Liu ◽  
Feng-Chang Cheng ◽  
Da-Hua Shi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Sodium Hydroxide ◽  
Acetylcholinesterase Inhibitors ◽  
Acetylcholinesterase Inhibition ◽  
Inhibition Activity ◽  
Triazole Derivatives ◽  
Inhibitory Activities ◽  
Ellman’S Method

AbstractNew C2-glycosyl triazole derivatives 6a–l were synthesized by cyclization of glycosyl acylthiosemicarbazides 5 in refluxing 3 N sodium hydroxide aqueous solution. Substrates 5 were obtained by the reaction of glycosyl isothiocyanate 3 with various hydrazides. The acetylcholinesterase (AChE) inhibitory activities of compounds 6 were tested by Ellman’s method. Compounds that exhibited over 85% inhibition were subsequently evaluated for the IC50 values. Compound 6f possesses the best acetylcholinesterase-inhibition activity with IC50 of 1.46±0.25 μg/mL.

scholarly journals SYNTHESIS, CHARACTERIZATION AND ANTIOXIDANT ACTIVITY OF 7-HYDROXY-3',4'-DIMETHOXYFLAVONE

2012 ◽  
Vol 12 (2) ◽  
pp. 146-151 ◽  
Author(s):  
Elfi Susanti VH ◽  
Sabirin Matsjeh ◽  
Tutik Dwi Wahyuningsih ◽  
Mustofa Mustofa ◽  
Tri Redjeki
Keyword(s):  
Aqueous Solution ◽  
Antioxidant Activity ◽  
Sodium Hydroxide ◽  
Spectral Data ◽  
1H Nmr ◽  
13C Nmr ◽  
Room Temperature ◽  
Antioxidant Activities ◽  
Oxidative Cyclization ◽  
Dpph Method

Synthesis of flavones and their derivatives has attracted considerable attention due to their significant pharmaceutical effects. 7-hydroxy-3',4'-dimethoxyflavone has been synthesized and its antioxidant activity has been investigated. Flavone was synthesized by oxidative cyclization of chalcone. 2',4'-dihydroxy-3,4-dimethoxychalcone was prepared by Claisen-Schmidt condensation of 2,4-dihydroxyacetophenones with 3,4-dimethoxybenzaldehydes in the presence of aqueous solution of sodium hydroxide and ethanol at room temperature. Oxidative cyclization of 2',4'-dihydroxy-3,4-dimethoxychalcone was done by using I2 catalyst in DMSO to form 7-hydroxy-3',4'-dimethoxyflavone. The synthesized compounds were characterized by means of their UV-Vis, IR, 1H-NMR and 13C-NMR spectral data. The compound was tested for their antioxidant activities by DPPH method.

scholarly journals Evidence-based practices of effective fire safety education programming for children

2021 ◽  
Vol 10.47389/36 (No 2) ◽  
pp. 34-41
Author(s):  
Kamarah Pooley ◽  
Sonia Nunez ◽  
Mark Whybro
Keyword(s):  
Fire Safety ◽  
Evidence Based ◽  
Safety Education ◽  
Education Programs ◽  
Evidence Based Practices ◽  
Fire Services ◽  
School Based ◽  
The World ◽  
Evidence Based Guidelines ◽  
Safety Knowledge

School-based fire safety education programs are implemented by fire services organisations around the world to improve children’s fire safety knowledge and skills. Such education is considered the single most modifiable strategy that fire services organisations can implement to reduce the risk that children will misuse fire or be harmed by fire. Despite this, there are no overarching and evidence-based guidelines for the development of new programs or the evaluation and modification of existing ones. To fill this void, a rapid evidence assessment of existing literature was conducted. Results revealed 25 evidence-based practices that held true in a variety of contexts and methodologically diverse studies. These practices inform an empirical framework that can be used to guide fire safety education programs for children.

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