• Journal of Marine Bioscience and Biotechnology
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• v.6 no.2
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• pp.47-52
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• 2014

Oxidation stability and cold fuid property are considered as the most important factors for determining biodiesel quality. Among the fatty acids, monounsaturated fatty acid satisfy both oxidation stability and cold flow property of biodiesel quality standards. Microalgae with high monounsaturated fatty acid contents is have some benefit for producing to produce biodiesels with satisfying quality standards. In this study, monounsaturated fatty acid contents of a isolated microalga from Youngheung island was analyzed. Phaeodactylum tricornutum was isolated by streaking, and growth rate and fatty acid composition of the algae were investigated. Total FAME contents were consisted of 26% of saturated fatty acids, 43% of monounsaturated fatty acids, and 18% of polyunsaturated fatty acids. The contents of monounsaturated fatty acid were especially high in the Phaeodactylum species. This result implies that the FAMEs from P. tricornutum may contribute to improve the oxidation stability and cold flow property of biodiesel.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.4
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• pp.391-401
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• 2009

The successful outcome of dental implants is mainly the result of intial implant stability following placement. The aim of this study was to investigate the effect of a self-tapping blades and implant design on initial stability of two tapered implant systems in poor bone quality. The two different implant systems included one with self-tapping blades and one without self-tapping blades. D4 bone model using Solid Rigid Polyurethane Form was used to simulate poor bone densities. The insertion torque during implant placement was recorded. Resonance frequency Analysis (RFA), measured as the implant stability quotient (ISQ), was assessed immediately after insertion. Finally, the implant-bone specimen was transferred to an Universal Testing Machine to measure the axial pull-out force. Insertion torque values and maximum pull-out torque value of the non self-tapping implants were significantly higher than those in the self-tapping group (P = 0.008). No statistically differences were noted between the two implant designs in RFA. Within the each implant system, no correlation among insertion torque, maximum pull-out torque and RFA value could be determined. Higher insertion torque of the non-self-tapping implants appeared to confirm higher clinical initial stability. In conclusion, implants without self-tapping blades have higher initial stability than implants with self-tapping blades in poor bone quality.

• The Korean Journal of Food And Nutrition
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• v.30 no.5
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• pp.960-972
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• 2017

The objectives of this study was to investigate the properties and stability of the wet noodles added to nanoemulsion as a industrial model system, and in so doing, survey practical applicability in the food industry. In order to test out these objectives, the characteristics and stability of the wet noodles added to nanoemulsion were investigated and their cooking characteristics and capsaicinoids loss were examined. As a result, the test results showed that the findings indicated that the post-cooking loss of capsaicinoids in the wet noodles added to double-layer nanoemulsion covered with chitosan was less than the losses in the wet noodles added to any other noodles. More especially, this demonstrates that the noodle added to double-layer nanoemulsion covered with chitosan scored significantly higher than the others with reference to their cooking properties, color, texture, stability for storage stability, and sensory evaluation. These results show that the findings of this study demonstrated that the noodles added to nanoemulsions could be produced as a food-grade merchandise because they could provide enhanced encapsulation capacity of capsaicinoids and higher acceptability.

• Mass Spectrometry Letters
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• v.14 no.4
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• pp.166-172
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• 2023

The utilization of methyl 2-aminobenzoate as a biocide and pesticide has raised concerns regarding its potential toxicity. To assess its safety, it is crucial to determine its quantity and related toxicity using reference materials (RMs) or certified reference materials (CRMs). As an RM and CRM containing methyl 2-aminobenzoate within a biocidal product matrix is currently unavailable, this study aimed to produce a high-quality RM containing methyl 2-aminobenzoate, ensuring its homogeneity and stability, following the ISO Guide 35 and ISO 17034. The study determined that the produced RM exhibited homogeneity, as indicated by a calculated F-value (1.91) smaller than the critical F-value (3.02). In the assessment of isochronous short-term stability, the slope of the linear regression for the RM showed no statistically significant difference from zero when stored at temperatures of 4, 18, and 60 ℃ for 4 weeks. Regarding classical long-term stability, the RM demonstrated sustained stability over the course of one year when stored at 4 ℃. This study has successfully developed an RM for monitoring methyl 2-aminobenzoate in biocides and pesticides. Its quality underwent rigorous evaluation, confirming both homogeneity and stability.

• Journal of Astronomy and Space Sciences
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• v.25 no.4
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• pp.445-458
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• 2008

Image chain analysis of synthetic aperture radar (SAR) satellite is one of the primary activities for satellite design because SAR image quality depends on spacecraft bus performance as well as SAR payload. Especially, satellite pointing and stability error make worst effect on the original SAR image quality which is implemented by SAR payload design. In this research, Image chain analysis S/W was developed in order to analyze the SAR image quality degradation due to satellite pointing and stability error. This S/W consists of orbit model, attitude control model, SAR payload model, clutter model, and SAR processor. SAR raw data, which includes total 25 point targets in the scene of $5km{\times}5km$ swath width, was generated and then processed for analysis. High resolution mode (spotlight), of which resolution is 1m, was applied. The results of image chain analysis show that radiometric accuracy is the most degraded due to the pointing error. Therefore, the successful design of attitude control subsystem in spacecraft bus for enhancing the pointing accuracy is most important for image quality.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.260-264
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• 1992

In present paper, we investigated the quality stability of sardine burgers during storage at $-20{\pm}2^{\circ}C$. During frozen storage of sardine burger, the PH were decreased, while volatile basic nitrogen contents were increased. The results of changes in peroxide values, thiobarbituric acid values, fatty acid compositions and color values during frozen storage showed that lipid oxidation and discolorization of antioxidant treated sardine burger and vacuum packed sardine burger could be effectively retarded. The changes in the taste compounds such as free amino acid, nucleotide and their related compounds, total creatinine, betaine and trimethylamine oxide, total amino acids and texture profile analysis of vacuum packed sardine burger were negligible during frozen storage. From the results of sensory evaluation and chemical experiments, the vacuum packed sardine burger could be preserved in good quality during frozen storage of 90 days.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1013-1030
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• 2018

Biodiesel is a fuel produced in the form of a fatty acid methyl ester by using raw materials such as animal fat, vegetable oil and its by-products, and is being seen as a biofuel that can replace petroleum energy. However unsaturated fatty acid methyl esters in biodiesel causes to oxidize during storage and distribution, resulting in poor fuel quality and corrosion of vehicle engine components. In this study, the influence of quality and oxidation characteristics of biodiesel on the oxidation stability is investigated and the evaluation method related it is described. We also propose a method to improve the drawback of oxidation stability in biodiesel.

• Tribology and Lubricants
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• v.38 no.2
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• pp.41-52
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• 2022

Mineral electrical insulating oil, which is widely used in transformers, exhibits excellent cooling performance and transformer efficiency. However, given that it is composed of petroleum-based components, it is weak in terms of biodegradability. This causes environmental problems in case of leakage and a low flash point, which is a factor that would cause great damage in the event of a fire in a substation. In this context, the use of eco-friendly electric insulating oil composed of bio-based vegetable oil and synthetic ester, which has excellent biodegradability and flame retardancy performance, has recently been expanded to the field of electric power, and various research and development (R&D) studies are in progress. According to different research results, vegetable oil and synthetic ester manufacturing technology, thermal stability, oxidation stability, property change, and quality control, which are characteristics of eco-friendly electrical insulating oils, are major factors affecting the maintenance of insulating oil properties. In addition, power companies have established and operated quality control standards according to the use of eco-friendly electrical insulating oil as they expand the exploitatoin of renewable energy in electricity production. In particular, deterioration and oxidation characteristics were jointly identified in R&D as an important influencing factor according to the content of saturated and unsaturated fatty acids present in vegetable oils and synthetic esters in power transformer applications.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.242-250
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• 2007

This study evaluated the storage stability of a variety of sauce products in the Korean market, determined primary quality indices for three typical products, and proposed functional relationships that are useful for determining shelf life at different temperatures. Most of the products examined were found to combine hurdles of low pH, low water activity, and the use of heat processing as methods for producing the required storage stability while maintaining the sensory quality of the products. For a meat extract solution produced for cold noodles (pH=4.3; $a_w=0.98$), the primary quality change determining shelf life was lipid oxidation, determined here by the TBA value. The primary quality index of a soybean paste seasoning mix (pH=4.0; $a_w=0.78$), which had a microbial load of 2.8 log (CFU/g), was a decrease in its pH. The primary quality index for a sandwich spread (pH=4.0; $a_w=0.88$) was changes in its surface color. The temperature dependence of changes in the primary quality indices can be described by the Arrhenius equation, which can estimate the shelf life at any arbitrary limit as a function of temperature. The activation energies for changes in the primary quality indices of the meat extract solution, the soybean paste seasoning, and the sandwich spread were 20.3, 27.2, and 43.5 kJ/mol, respectively.

• The Korean Journal of Nuclear Medicine
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• v.4 no.1
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• pp.51-60
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• 1970

In 1969 this laboratory had prepared 131 mc. of radiopharmaceuticals in total (Hippuran and other four kinds) and distributed to the major medical establishments. The quality and stability of these products were reviewed by means of radio paper partition chromatography and thin layer chromatography and results were compared to those of foreign products. Generally, the quality and stability of the product of this laboratory were better than those of the foreign product, even though the properties of the radiopharmaceutical were varied by the procedure of the preparation adopted. Various precautions for handling radiopharmaceuticals for clinical use were also described with a view of quality control and stability test there of.