• Structural Engineering and Mechanics
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• v.82 no.2
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• pp.163-172
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• 2022

Zinc-rich epoxy (ZRE) is used to overcome corrosion problems in reinforced concrete (RC) beams and coat steel rebars to protect them from humidity and chlorides. An extra coating layer of Sikadur-31 epoxy (SDE) is utilised to increase bond strength because the use of ZRE reduces the bond strength between concrete and steel rebars. However, the low melting point of SDE indicates that concrete specimens are vulnerable to fire. An experimental investigation on flexural performance of RC beams incorporating ZRE-SDE coating of steel rebars that were destroyed by fire is performed in this study. Twenty beams of five concrete mixes with different cementitious contents were tested to compare fire exposure for coated and uncoated rebars of the same beams at room temperature and determine the optimal cementitious content. Scanning electron microscopy (SEM) was also applied to investigate characteristics of fired mixture samples. Results showed that the use of SDE-ZRE at room temperature improves flexural strengths of the five mixes compared with uncoated rebars with percentages ranging from 8.5% to 12.3%. All beams with SDE-ZRE lost approximately 50% of their flexural strength due to firing. Moreover, the mix incorporating SF (silica fume) of 15% and cement content of 400 kg/m³ introduces optimum behaviour compared with other mixes. All results were supported and verified by the SEM analysis and compressive strength of cubic specimens of the same mixes.

• Bulletin of the Korean Mathematical Society
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• v.38 no.1
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• pp.129-136
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• 2001

We consider a solution process of stochastic differential equation(SDE) driven by S'($R^d$)-valued Wiener process and study a large deviation type of estimates for the process. We get an upper bound in exit probability for such a process to leave a ball of radius $\tau$ before a finite time t. We apply the Ito formula to the SDE under the structure of nuclear space.

• Smart Structures and Systems
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• v.21 no.3
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• pp.321-333
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• 2018

Simplified Dolphin Echolocation (SDE) algorithm is a recently developed meta-heuristic algorithm. This algorithm is an improved and simplified version of the Dolphin Echolocation Optimization (DEO) method, based on the baiting behavior of the dolphins. The main advantage of the SDE algorithm is that it needs no empirical parameter. In this paper, the SDE algorithm is applied for optimization of three well-studied frame structures. The designs are then compared with those of other meta-heuristic methods from the literature. Numerical results show the efficiency of the SDE algorithm and its competitive ability with other well-established meta-heuristics methods.

• The KIPS Transactions:PartA
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• v.11A no.1
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• pp.37-48
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• 2004

The SyncML, the standard synchronization protocol, supports the synchronization of various application services between a client and a server such as an address book, a calendar. Even with this standard protocol, SyncML application developers usually spend a long time and efforts implementing service specific logics and databases. This paper designed and implemented the SDE(Service Development Environment) which is an integrated development environment for SyncML server developers to develop an application service rapidly and correctly. The SDE consists of two components i.e., the Sync Library and the SEG(Sync Engine Generator) tool. To prove the applicability of this study we implemented a SyncML server by using the SDE and also carried out the correctness tests and the performance test. We hope this system helps developers implement mobile application services more efficiently.

• Food Science and Preservation
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• v.13 no.2
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• pp.269-272
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• 2006

Aroma compounds in chungkukjang with Astragalus membranaceus (Hwangki) were extracted by the simultaneous distillation and extraction (SDE), headspace and solid phase microextraction (SPME), and aroma compounds obtained by this method were identified with GC-MS. Thirty compounds were identified, including six ketones, eight alcohols, three heterocyclic compounds, three aldehydes, five hydrocarbones and five other compounds. Major aroma compounds were identified as 3-hydroxy-2-butanone, 2-furanmethanol, 2-methoxy-4-vinylphenol, and 4-vinylphenol in SDE, 2,3-butanedione, 3-hydroxy-2-butanone, ethanol, 2,6-dimethyl pyrazine and acetic acid in headspace and acetone, ethanol, 2,5-dimethyl pyrazine, tetramethyl pyrazine and acetic acid in SPME. The content of pyrazines identified in headspace and SPME methods was higher than that of SDE method, and the content of pyrazines containing 2,5-dimethyl pyrazine, 2,6-dimethyl pyrazine and tetramethyl pyrazine in chungkukjang was higher than that of Hwangki chungkukjang.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.49-57
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• 2000

To understand the effects of drying conditions on changes of volatile compounds in fruits of Schizandra chinensis, we analyzed SDE (steam distillation and extraction) extract and Headspace vapor of fresh and dried samples using GC/MS (Gas chromatograph/Mass spectrometer). Contents of essential oils from samples with different drying conditions were 0.58% in fresh ones, 0.60% in freeze dried ones, and 0.30% in hot-air dried ones. In SDE extract, major volatile compounds in fresh samples were terpinen-4-ol(9.01%), ${\gamma}-terpinene(7.02%),\;{\beta}-myrcene(7.55%)$, unidentified sesquiterpenes(28.48%), showing almost the same composition as that in freeze-dried ones, but those in hot-air dried samples at $60^{\circ}C$ were ${\gamma}-terpinene(5.40%),\;{\alpha}-elemene(8.28%)$, unidentified sesquiterpenes(50.38%), indicating the chemical changes during drying procedure. In Headspace vapor, major compounds in fresh samples were ${\beta}-myrcene(22.05%),\;{\gamma}-terpinene(9.47%),\;{\alpha}-pinene(8.91%)$, sabinene(8.48%), which were different from those in SDE extract. In chemical compositions of volatile compounds in dried samples, ${\beta}-myrcene,\;{\alpha}-terpinene$ decreased in the order of freeze-drying > hot-air drying at $60^{\circ}C$ > hot-air drying at $60^{\circ}C$, and ${\alpha}-ylangene,\;{\alpha}-pinene$, camphene increased in the reverse order of the former. We observed the changes of the contents and compositions of essential oils compounds during drying procedure, especially a decrease in monoterpenes and alcohols and an increase in sesquiterpenes with relatively weak volatility.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1615-1621
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• 2008

The characteristics of volatile flavor compounds of Fuji apples were compared by different extraction methods for information leading to a natural fragrance development. The volatile flavor components of Fuji apples were extracted using simultaneous steam distillation and extraction (SDE), solvent extraction (SE), and solid-phase microextraction (SPME) methods and then analyzed by gas chromatograph-mass spectrometer. A total of 66, 32 and 54 components were identified in SDE, SE and SPME extracts, respectively. (E,E)-$\alpha$-Farnesene, hexanol, butanol, 2-methyl butanol, hexyl hexanoate, hexyl 2-methyl butanoate, hexyl butanoate, and butyl hexanoate were the major flavor components in the extracts by different methods, but the composition of volatiles in the extracts were different. Alcohols and hydrocarbons were the major functional groups in SDE and SE extract whereas esters and hydrocarbons were the major functional groups in SPME extracts. SPME was the most suitable method for analysis of fresh volatiles from Fuji apples.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.339-344
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• 2005

Volatile compounds, isolated from Elsholtzia splendens using simultaneous steam distillation extraction (SDE) and headspace solid phase microextraction (HS-SPME), were analyzed by gas chromatography/mass spectrometry(GC-MS). Twenty-nine compounds, comprising 3 aldehydes, 7 alcohols, 11 hydrocarbons, 5 ketones, and 3 miscellaneous ones, were tentatively identified from volatile compounds of Elsholtzia splendens flowers. From leaves, 30 compounds, comprising 3 aldehydes, 6 alcohols, 11 hydrocarbons, 6 ketones, and 11 miscellaneous ones, were tentatively identified. Volatile compounds extracted by HS-SPME in E. splendens flowers were 3 alcohols, 18 hydrocarbons, 3 ketones, and 2 miscellaneous ones. In leaves, 31 compounds, comprising 7 alcohols, 15 hydrocarbons, 7 ketones, and 2 miscellaneous ones, were tentatively identified. Major volatile compounds identified by SDE and HS-SPME were naginataketone and elsholtziaketone, which were identified as aroma-active compounds, representing characteristic aroma of E. splendens.

• Journal of Life Science
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• v.20 no.11
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• pp.1648-1655
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• 2010

The flavor extracts of Mideoduck muscle and its juices were concentrated by simultaneous distillation and extraction (SDE) and solid-phase microextraction (SPME) methods. Each component present in the extracts was identified with GC and GC-MS by the n-paraffin hydrocarbon retention index and standard MS library data system. By SDE, $371.3\;{\mu}g/g$ of hexanal, $80.1\;{\mu}g/g$ of 1-tridecanol, $72.1\;{\mu}g/g$ of (Z)-4,5-dimethylhex-2-en-4-ol with other alcohols, aldehydes and acids were present in the flavor extracts, with the alcohols having the highest composition and being the most important factor in Mideoduck muscle flavor. By SPME, 9 alcohols, 1 acid, 1 aldehyde, 1 hydrocarbon, 1 ester, 1 amine and 2 ketones were detected in the extracts, with alcohol such as 1-nonanol, 1-decanol and 1-tridecanol as the major components. In SPME, the muscle sample, consisting of $31.6\;{\mu}g/g$ of 1-nonanol, $20.3\;{\mu}g/g$ of (E)-2-butenedioic acid dibutylester, and $26.7\;{\mu}g/g$ of heptadecanoic acid made up the 62.1% of total flavor extracts of Mideoduck muscle. The results of the SPME methods were similar to the composition of the raw material flavor of the sample even at a low concentration.

• Food Science and Preservation
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• v.13 no.1
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• pp.108-114
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• 2006

This study was conducted to determine the volatile flavor compositions of the essential oil and the headspace of Capsella bursa-pastoris Medicus. Essential oil and headspace from the plant were extracted by simultaneous steam distillation extraction (SDE), and solid-phase microextraction(SPME) methods, respectively. Seventy-two compounds including 28 hydrocarbons, 4 aldehydes, 6 ketones, 16 alcohols, 4 esters, 8 acids, and 6 miscellaneous ones were identified in the leaf essential oil extracted by SDE method Sixty-eight compounds including 26 hydrocarbons, 2 aldehydes, 6 ketones, 17 alcohols, 4 esters, 6 acids, and 7 miscellaneous ones were identified in the root essential oil. According to the instrumental analyses the essential oil, phytol ($21.12\%$ in leaves, $20.94\%$ in roots) was the most abundant compound Alcohols, esters, and acids were main groups of the essential oil. On the other hand, thirty-eight compounds including 18 hydrocarbons, 3 aldehydes, 3 ketones, 9 alcohols, 2 esters, 3 miscellaneous ones were identified in the leaf headspace by SPME. In root headspace, thirty-three compounds including 16 hydrocarbons, 2 aldehydes, 1 ketone, 9 alcohols, 3 esten;, and 2 miscellaneous ones were identified. Hydrocarbons($44.02\%$ in leaves, $56.98\%$ in roots) were the main components of the headspace of Capsella bursa-pastoris Medicus.