• Journal of the Korean Burn Society
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• v.23 no.1
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• pp.7-12
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• 2020

Purpose: Due to rapid changes in the industrial structure in last decade, the wider various types of chemical agents were introduced. Burn surgeons should be well-informed with rapid changes of chemical burns. We present the recent incidence trends of causing agents of chemical burns. Methods: From 2010 to 2019, 92 chemical burn victims were included in this study. A retrospective study was made about the type, distribution and incidence of the causing agents of chemical burns. Initial treatments of most chemical burn wounds are copious saline irrigation by tap water, except hydrofluoric acid burn cases managed by 10% calcium gluconate injection. In alkali chemical burns on extremity, if thin eschars appear in postburn 2~3 days, acute early surgical escharectomy and split thickness skin graft were done. Results: More than 9 types of major chemicals causing chemical burns were surveyed, and the most common causing agent of chemical burns was Hydrofluoric acid (23.9%) followed by Acetic acid (19.6%) and Sodium hydroxide (8.7%). Conclusion: From 2010 to 2019, changes in the causing agent of chemical burns are that the types of major causing agents of chemical burns have increased and the distribution and incidence of causing agents have changed compared to previous reports. According to this study, more than 9 types of major chemicals causing chemical burns were surveyed, and the most common causing agent of chemical burns was Hydrofluoric acid (23.9%) followed by Acetic acid, Sodium hydroxide.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5595-5600
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• 2012

This paper is to review and study about the crystallization nucleating agent to improve the heat-resistance properties of poly(lactic acid). Four sub-micron sized nucleating agents, metallic salts of 2,2'-methylene bis(4,6-di-tert-butylphenol), were prepared and used as a crystallization nucleating agent. Thermal and mechanical properties of polymer compounds were investigated by DSC, HDT and UTM. As the results, While the heat-resistance properties of the polymer compound samples were increased linearly with the contents of nucleating agent as well as their smaller size. Among them, the highest heat-resistance property of compound was observed with 2 wt% of MPZ2. HDT values of PL98Z2 compound was $116^{\circ}C$ at 0.455Mpa.

• YAKHAK HOEJI
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• v.27 no.4
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• pp.257-261
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• 1983

Binding of nalidixic acid which is used primarily in the treatment of urinary infection and probenecid which is used as a uricosuric agent to bovine serum albumin were studied using difference spectrophotomeric method. 2-(4'-Hydroxybenzeneazo) bcnzoic acid as a spectrophotometric probe was used for measuring the binding of nalidixic acid and probenecid to bovine serum albumin. The association constants of nalidixic acid and probenecid were $1.58{\times}10^{4}M^{-1}$ and $1.70{\times}10^{4}M^{-1}$, respectively.

• Textile Coloration and Finishing
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• v.20 no.5
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• pp.1-6
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• 2008

3-(Hydroxyphenyl phosphinyl) propanoic acid (HPPA) has been one of the most commonly used durable flame retardant agents for polyethylene terephthalate (PET) for many years. We intended to explore the application of HPPA to cellulose fabrics as formaldehyde-free phosphorus based flame retardants (FRs) through green chemistry process. The flame retardancy of the flame-retardant treated cellulose fabrics were characterized by using inductively coupled plasma spectroscopy (ICP) and limiting oxygen index (LOI). Structural changes of the treated cellulose fabrics were carried out by thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy. To enhance the flame retardancy of HPPA treated cellulose fibers, glycerol polyglycidyl ether (GPE), a crosslinking agent was employed. Both HPPA and GPE treated cotton fabric imparted an LOI value over 26.

• Investigative Magnetic Resonance Imaging
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• v.19 no.1
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• pp.52-55
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• 2015

Supradiaphragmatic liver is a rare condition. Establishing an accurate preoperative diagnosis is difficult. Operative exploration is necessary to differentiate this lesion from intrathoracic masses, such as a pleural based tumor, diaphragmatic tumor and peripheral lung tumor. However, with the aid of the hepatocyte-specific magnetic resonance imaging contrast agent, gadoxetic acid (Gd-EOB-DTPA), functional hepatocytes in the lesion can be identified in the hepatobiliary phase, potentially allowing an accurate and non-invasive diagnosis. We report a case of supradiaphragmatic liver diagnosed by Gd-EOB-DTPA-enhanced magnetic resonance imaging.

• Journal of the Korean institute of surface engineering
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• v.19 no.3
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• pp.109-120
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• 1986

The electroless nickel plating on high alumina ceramics was performed in the bath containing nickel chloride, sodium hypophosphite and mono- or bi-carboxylic acid as a complexing agent in order to examine the empirical rate law as well as the effects of the complexing agent, plating temperature and pH on the rate of deposition. Adding the carboxylic acid to the plating bath, the rate of deposition was increased considerably, and each of the complexing agents showed a maximum deposition rate plateau around a particular concentration of the complexing agent. The rate of deposition was increased with increasing either temperature or pH, but microstructure of the surface became more rough. Furthermore, empirical rate law of the elecltroless nickel deposition on high alumina ceramics was discussed with the activation energy and other rate parameters calculated.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.542-549
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• 1997

HFC-227ea and HCFC Blend A were evaluated using full-scale fire tests to obtain information on their fire suppression performance, drop-in capability, thermal decomposition products and physical behaviour of the agent such as its flow characteristics in the piping system. Also, full-scale tests were conducted with Halon 1301 to provide a basis for comparison. Halon 1301, at concentrations of 5% to 7.5%, showed effective total-flooding fire- extinguishing performance for all test scenarios. HFC-227ea, at a design concentration of 7.6% or higher, and HCFC Blend A, at a design concentration of 12%, extinguished all fires in the test facility, however, these agents produced higher concentrations of acid gases than Halon 1301. The quantity of the acid gases generated during fire suppression was dependent on agent concentration, agent discharge time, fire type and size as well as extinguishment time.

• Textile Coloration and Finishing
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• v.11 no.2
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• pp.55-63
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• 1999

The purpose of this study was to investigate the purification of chitin and chitosan for textile finishing agent from crab shell. Weight loss rate(removing Ca and protein), degree of deacetylation, solubility and MIC(Minimum growth inhibitory concentration) value of chitosan and molecular weight of the treated crab shell were measured. The results of this study were as follows : 1) Weight loss rate(removing Ca) of crab shell treated with HCI increased with the concentration of HCI and treatment time, but it became constant over 60 min. of treatment time. 2) Weight loss rate(removing protein) of crab shell treated with NaOH(0.5N∼2N) increased with the concentration of NaOH and treatment temperature and time, but it became constant above loot of temperature and over 200 min. of treatment time. 3) Degree of deacetylation of chitin treated with NaOH increased with the concentration of NaOH(40∼60％), but molecular weight decreased and thus MIC value increased. 4) Concentration of acetic acid should be above 0.3％ to dissolve chitosan easily. Solubility for chitosan was the highest with formic acid, and the next was acetic acid, hydrochloric acid, lactic acid and sulfuric acid in order.

• Journal of Soil and Groundwater Environment
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• v.23 no.1
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• pp.14-24
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• 2018

In soil washing, there are many variables including types of reagent and contaminant, washing time, soil-liquid ratio, washing cycles, washing agent concentrations, and etc. To identify the most influencing factors on soil washing process, regression analysis was performed for eight single variables and five combined variables. A quantitative model that employs W/H (molar ratio of washing agent to heavy metal) as a major variable was established based on the regression. The validity of the model was demonstrated by conducting lab experiments with Cu, Pb, Zn, Ni and As-contaminated soils, and various washing reagents including acetic acid, citric acid, malic acid, oxalic acid, ethylenediamine tetraacetic acid (EDTA) and nitriloacetic acid (NTA). The washing efficiencies were compared with the EDTA washing data reported in the literature. The correlation between W/H and removal efficiency was analyzed after dividing data into two groups according to the heavy metal mobility.

• Polymer(Korea)
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• v.29 no.5
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• pp.445-450
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• 2005

Hyaluronic acid-based beads were prepared in order to develop a biomedical material for augumentation. Hyaluronic acid was crosslinked by 1,3-butadiene diepoxide in a suspension state maintained by rapid mixing of soybeen oil and hyaluronic acid solution. The particle size, surface area and swelling ratio were measured to investigate the physical properties of the synthesized beads and the bead surface was examined by scanning electron microscopy. The beads were formed in the range of $5-12vol\%$ concentration of crosslinking agent, which showed monodisperse size distribution. Both BET surface area and swelling ratio decreased as the concentration of either hyaluronic acid or crosslinking agent increased, and crosslinking temperature decreased. Bead size could be effectively controlled by mixing speed without affecting other physical property.