• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.73-74
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• 2022

The corrosion inhibitive effect of a new hydrazone-based heterocyclic compound for steel in simulated concrete pore solution with 3.5 wt.% sodium chloride was investigated by experimental and computational techniques. Electrochemical studies, up to 30 days of immersion, and surface analysis (X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscope (SEM)) were performed to assess the corrosion protection abilities of investigated compound for steel rebar. Results showed that adding the organic compound to the chloride contaminated concrete pore solution decreased the corrosion rate of the steel rebar thanks to the effective adsorption of inhibitor molecules. After 30 days of immersion of steel rebar in inhibited chloride contaminated synthetic concrete pore solution, the inhibition efficiency exceeded 80% at low concentration of 1 mmol/L. Computational studies by Density Functional based Tight Binding (DFTB) method revealed the formation of covalent bonds between the hydrazone molecule and the iron surface.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.6
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• pp.1485-1494
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• 2015

Traditionally, data hiding has been done mainly in such a way that insert the data into the large-capacity multimedia files. However, the document files of the previous versions of Microsoft Office 2003 have been used as cover files as their structure are so similar to a File System that it is easy to hide data in them. If you open a compound-document file which has a secret message hidden in it with MS Office application, it is hard for users who don't know whether a secret message is hidden in the compound-document file to detect the secret message. This paper presents an analysis of Compound-File Binary Format features exploited in order to hide data and algorithms to detect the data hidden with these exploits. Studying methods used to hide data in unused area, unallocated area, reserved area and inserted streams led us to develop an algorithm to aid in the detection and examination of hidden data.

• Advances in Traditional Medicine
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• v.10 no.1
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• pp.21-28
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• 2010

The objective of the present investigation is to evaluate the antimicrobial potency of the terpenoid fractions isolated from Luffa cylindrica seeds against various pathogenic microbes. The seeds were powdered and extracted with methanol in soxhlet appratus based on phytochemical screening. Three terpenoid components were isolated by column chromatography and identified by thin layer chromatography and chemical analysis which were designated as ${LCSF_4}^*$, ${LCSF_6}^*$ & ${LCSF_8}^*$ respectively. Disc diffusion method was employed to determine the antimicrobial effectiveness of test compounds I, II and III $({LCSF_4}^*,\;{LCSF_6}^*\;&\;{LCSF_8}^*)$ against 6 microbial species viz., Staphylococcus (S.) aureus, Bacillus (B.) subtilis, Escherichia (E.) coli, Pseudomonas (P.) aeruginosa, Candida (C.) albicans and Aspergillus niger. The disc was saturated with $100{\mu}l$ of each compound, allowed to dry and introduced on the upper layer of seeded agar plate. The plates were incubated overnight at $37^{\circ}C$. Microbial growth was determined by measuring the zonal inhibition diameters. Compound I showed maximum potency against gram positive S. aureus (21 mm) in comparison with standard ciprofloxacin (38 mm), whereas the same compound was completely devoid of activity against both the fungi tested. Compound II was found to be highly sensitive against both the gram negative E. coli (20 mm) and P. aeruginosa (22 mm). Compound II was found to exhibit maximum potency against the fungi C. albicans (15 mm) and A. niger (20 mm). Compound III was found to be very effective against both the gram positive S. aureus (20 mm) and B. subtilis (15 mm) respectively.

• Journal of the Korean Society for Heat Treatment
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• v.5 no.4
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• pp.215-223
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• 1992

This study has been performed to investigate into some effects of temperature, gas mixing ratio and time on the optical microstructure, hardness and wear characteristics of medium carbon alloy steel treated by plasma nitriding. The results obtained from the experiment are summarized as follows: (1) Optical micrographs of AISI 4140 steel plasma-nitrided by the double stage technique have revealed that the nitrided layer is composed of the compound layer and the diffusion layer. The variation in temperature at the first stage gives effects, on the formation of compound layer and the growth rate is shown to be relatively fast at $460^{\circ}C$. (2) The thickness of compound layer has been found to increase with increasing nitrogen percentage in the gas mixture and the holding time. It is therefore recommended that a shorter holding time and a lower nitrogen percentage are more effective to produce a tougher compound layer and a diffusion layer only. (3) X-ray diffraction analysis for AISI 4140 steel has shown that the compound layer consist of ${\gamma}^{\prime}-Fe_4N$ and ${\alpha}-Fe$ and that tough compound layer diffustion layer only can be obtained by the double stage plasmanitriding process. (4) There is also a tendency that the total hardened layer depth increases with increasing temperature, time and nitrogen percentage in the first stage during the double stage plasma nitriding. (5) The wear resistance of plasma nitrided specimens has been found thobe considerably increased compared to the untreated specimens and the amount of increment has appeared to increase further with increasing nitriding temperature, holding time and notrogen percentage of gas mixture in the first stage treatment.

• Journal of Pharmacopuncture
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• v.19 no.3
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• pp.246-252
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• 2016

Objectives: The purpose of this study was to obtain a natural antibiotic from Phenol-rich compounds; for the dressing and the treatment of chronic wounds. Methods: The Phenol-rich compound sweet gel was prepared by blending four natural herbal extracts, Acacia catechu (L.F.), Momia (Shilajit), Castanea sativa, and Ephedra sinica stapf, with combination of a sweet gel medium, including honey, maple saps, Phoenix dactylifera L. (date), pomegranate extract and Azadirachta indica gum as a stabilizer. The combinations were screened by using a well-diffusion assay with cloxacillin as a control. Pseudomonas spp. was tested with our novel antimicrobial compound. The zones of inhibition in agar culture were measured for each individual component and for the compound, and the results were compared with those of the control group which had been treated with cloxacillin. Data were expressed as means ${\pm}$ standard deviations. Quantitative analyses were performed using the paired t-test. Results: The antibiotic effect of the Phenol-rich compound sweet gel was statistically shown to be more significant than that of cloxacillin against Pseudomonas aeruginosa (P < 0.05). Conclusion: Our novel approach to fighting the antibiotic resistance of Pseudomonas proved to be successful. The Phenol-rich compound sweet gel was found to be suitable for use as an alternative medicine and bioactive dressing material, for the treatment of patients with various types of wounds, including burns, venous leg ulcers, ulcers of various etiologies, leg ulcers on the feet of diabetic, unhealed graft sampling sites, abscesses, boils, surgical wounds, necrotic process, post-operative and neonatal wound infection, and should be considered as an alternative to the usual methods of cure.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.174-180
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• 2021

Chalcones exhibit multiple biological activities. Various studies have attempted to modify the structure of chalcones with a special focus on the addition of substituents to the benzene rings. However, these chemical modifications did not improve the water solubility and bioavailability of chalcones. Glycosylation can markedly affect the physical and chemical properties of hydrophobic compounds. Here, we evaluated the ability of a highly promiscuous glycosyltransferase (GT) BsGT1 from Bacillus subtilis ATCC 6633 to biosynthesize chalcone glucosides. Purified BsGT1 catalyzed the conversion of 4'-hydroxychalcone (compound 1), 4'-hydroxy-4-methylchalcone (compound 2), and 4-hydroxy-4'-methoxychalcone (compound 3), into chalcone 4'-O-β-D-glucoside (compound 1a), 4-methylchalcone 4'-O-β-D-glucoside (compound 2a), and 4'-methoxychalcone 4-O-β-D-glucoside (compound 3a), respectively. To avoid the addition of expensive uridine diphosphate glucose (UDP-Glc), a whole-cell biotransformation system was employed to provide a natural intracellular environment for in situ co-factor regeneration. The yields of compounds 1a, 2a, and 3a were as high as 90.38%, 100% and 74.79%, respectively. The successful co-expression of BsGT1 with phosphoglucomutase (PGM) and UDP-Glc pyrophosphorylase (GalU), which are involved in the biosynthetic pathway of UDP-Glc, further improved the conversion rates of chalcones (the yields of compounds 1a and 3a increased by approximately 10%). In conclusion, we demonstrated an effective whole-cell biocatalytic system for the enzymatic biosynthesis of chalcone β-D-glucoside derivatives.

• 전기의세계
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• v.22 no.6
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• pp.33-51
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• 1973

To lower the earth resistance shall be one of the most effective method for the prevention of lightening damage on power transmission line. In this report, in order to investigate various characteristic necessary to lowering the earth resistance, the following experiments have been made at 154KV U1San-PoHang T/L, 154KV YoSu-SoonChun T/L and so on. 1. Measurement of Earth specific resistance, 2. Efficiency of Earthing of concrete foundation for steel structure., 3. Efficiency of Earthing with counter poise., 4. Compound impulse test with foundation of steel structure and counter poise. With the above investigate a guidance have been prepared for the effective work-performance of steel structure.

• Applied Microscopy
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• v.40 no.4
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• pp.201-209
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• 2010

Korean traditional herbs, especially Anemarrhena asphodeloides (A. asphodeloides), Salvia miltiorrhiza (S. miltiorrhiza), and Terminalia chebula (T. chebula) have been known to have the immunomodulatory, anti-tumor, and anti-inflammatory effects. However, direct cellular mechanism underlying the mast cell-mediated anaphylaxis-like reaction has poorly been understood. In the present study, the effects of the methanol extracts of A. asphodeloides (MEAA), S. miltiorrhiza (MESM), and T. chebula (METC) on anaphylactic reaction were investigated. Using in vitro and in vivo experiments, the influences of MEAA, MESM, and METC on the compound 48/80-induced anaphylaxis-like reaction and mast cell activation, and IgEmediated PCA were examined. Results are below; 1) MEAA, MESM, and METC significantly inhibited systemic anaphylaxis-like reaction, ear swelling response, and IgE-mediated PCA. 2) the compound 48/80-induced mast cell degranulation, histamine release of rat peritoneal mast cells (RPMC) were significantly inhibited by the pretreatment with MEAA, MESM, and METC, and 3) the compound 48/80-induced calcium influx in RPMC was significantly inhibited by the pretreatment with MEAA, MESM, and METC. These results suggest that MEAA, MESM, and METC may be an activity to inhibit the compound 48/80-induced or anti-DNP IgE-mediated anaphylactic reactions by blocking histamine release and calcium uptake into RPMC. MEAA, MESM, and METC potentially may serve as an effective therapeutic tool for allergic diseases.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.1
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• pp.37-42
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• 1978

In other to find out the effect of N.K compound fertilizers, 17-0-17 and 17-0-14, a field experiment was conducted with rice (Oryza sativa L. Akibare). Results obtained were summarized as fellows: 1. The effect of compound fertilizer on the yield of paddy and nutrient uptake was not much differed from that of Urea and Muriate potassium. 2. It seemed that the compound fertilizer, 17-0-17, was rather pertinent for the top dressing at effective tillering stage than that at primodial stage, for its slow effectiveness. 3. From the viewpoint of increasing paddy yield and nutrients uptake as well as the exchangeable potassium content of soil after harvesting, it seemed necessary to give a serious consideration to the development of such a compound fertilizer as used in this experiment which was prepared by the Chosen Fertilizer Industrial Cooporation on a trial base.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.3
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• pp.133-139
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• 1979

In order to evaluate the effect of developed Nk compound fertilizers, 17-0-17 granular and powder, and 17-0-14 granules in comparison with single fertilizers, urea and potassium on rice (Oryzae sativa) ; cultivar, Milyang 23, (Orizae Sativa), a field experiment was carried out. Results obtained are as follows : 1. The top dressing of NK compound fertilizers tended to produce higher paddy yield than that of single fertilizers; urea and patasstum muriate. 2. The absorption of potassium and nitrogen by rice plant from the plot of NK granular compound fertilizer, 17-0-17, was greater than from the plots the absorption of those elements received other types of ferilizers and application method The absorded K/Ca+Mg ratio in milli equivalent basis in plant was also appeared to be in same order as the absorption of nitrogen and potassium. 3. From the results of present study it seemed necessary to evaluate the NK compound fertilizer for the top dressing at effective tillering stage of rice as well.