• Journal of Microbiology and Biotechnology
• /
• v.32 no.9
• /
• pp.1178-1185
• /
• 2022

Steroids are a class of compounds with cyclopentane polyhydrophenanthrene as the parent nucleus, and they usually have unique biological and pharmacological activities. Most of the biosynthesis of steroids is completed by a series of enzymatic reactions starting from cholesterol. Synthetic biology can be used to synthesize cholesterol in engineered microorganisms, but the production of cholesterol is too low to further produce other high-value steroids from cholesterol as the raw material and precursor. In this work, combinational strategies were established to increase the production of cholesterol in engineered Saccharomyces cerevisiae RH6829. The basic medium for high cholesterol production was selected by screening 8 kinds of culture media. Single-factor optimization of the carbon and nitrogen sources of the culture medium, and the addition of calcium ions, zinc ions and citric acid, further increased the cholesterol production to 192.53 mg/l. In the 5-L bioreactor, through the establishment of strategies for glucose and citric acid feeding and dissolved oxygen regulation, the cholesterol production was further increased to 339.87 mg/l, which was 734% higher than that in the original medium. This is the highest titer of cholesterol produced by microorganisms currently reported. The fermentation program has also been conducted in a 50-L bioreactor to prove its stability and feasibility.

• Steel and Composite Structures
• /
• v.39 no.4
• /
• pp.401-417
• /
• 2021

This study experimentally reveals the influence of welding on grade S690Q high strength steel (HSS) butt joints from both micro and macro levels. Total eight butt joints, taking plate thickness and welding heat input as principal factors, were welded by shielded metal arc welding. In micro level, the microstructure transformations of the coarse grain heat affected zone (CGHAZ), the fine grain heat affected zone (FGHAZ) and the tempering zone occurred during welding were observed under light optical microscopy, and the corresponding mechanical performance of those areas were explored by micro-hardness tests. In macro level, standard tensile tests were conducted to investigate the impacts of welding on tensile behaviour of S690Q HSS butt joints. The test results showed that the main microstructure of S690Q HSS before welding was tempered martensite. After welding, the original microstructure was transformed to granular bainite in the CGHAZ, and to ferrite and cementite in the FGHAZ. For the tempering zone, some temper martensite decomposed to ferrite. The performed micro-hardness tests revealed that an obvious "soft layer" occurred in HAZ, and the HAZ size increased as the heat input increased. However, under the same level of heat input, the HAZ size decreased as the plate thickness increased. Subsequent coupon tensile tests found that all joints eventually failed within the HAZ with reduced tensile strength when compared with the base material. Similar to the size of the HAZ, the reduction of tensile strength increased as the welding heat input increased but decreased as the thickness of the plate increased.

• ALGAE
• /
• v.37 no.2
• /
• pp.175-183
• /
• 2022

Polar microorganisms produce physiologically active substances to adapt to harsh environments, and these substances can be used as biomedical compounds. The green microalga Micractinium variabile KSF0031, which was isolated from Antarctica, produced phytol, a natural antimicrobial agent. Furthermore, several polyunsaturated fatty acids (PUFAs), including omega-3, exhibit antioxidant properties. Here statistical methods (Plackett-Burman design and Box-Behnken design) were used to optimize the culture medium of KSF0031 to improve biomass production, and K₂HPO₄, MgSO₄·7H ₂O, and ammonium ferric citrate green (AFCg) were selected as significant components of the culture medium. Changes in the concentration of K₂HPO₄ and MgSO₄·7H ₂O as positive factors and AFCg as a negative factor affected cell growth to a remarkable degree. The biomass production in a 100 L culture using the optimized medium for 24 d at 18℃ was improved by 37.5% compared to that obtained using the original BG-11 medium. The quantities of PUFAs and phytol obtained were 13 mg g^-1 dry cell weight (DCW) and 10.98 mg g^-1 DCW, which represent improved yields of 11.70% and 48.78%, respectively. The results of this study could contribute to an improved production of phytol and fatty acids from Antarctic microalgae in the biomedical industry.

• Journal of Fashion Business
• /
• v.27 no.1
• /
• pp.61-76
• /
• 2023

The purpose of this study was to derive exotic products handled by Bon Marche department store, examine characteristics, and reveal the meaning of exotic taste in the 19th century. The research method is literature research centered on original materials of the time, such as old literature related to department stores, and films, newspapers, magazines, and periodicals as well as books and papers. Commercial catalogs and Agenda-Buvard published by Bon Marché were used as visual materials. Results are as follows. Exotic tastes of products of the Bon Marche department store in the late 19th century showed an oriental style centered on Persia, India, China, and Japan. Products from various regions such as Turkey, Spain, Algeria, Tunisia, England, Italy, and Russia were also accepted. These exotic tastes had the following contributions and meanings. First, they expanded items and product development and activated domestic industry through production of imitations and replicas. Second, before the advent of department stores, foreign items that came to Europe were exclusive properties of a few privileged classes. However, in the late 19th century, as the number of consumers who wanted to have a new status higher than themselves increased, exotic products of the Bon Marche department store became the object of desire for material pursuits toward the upper class rather than sentimental fantasies. Third, exotic tastes gradually spread to the public as production of products imitating foreign products became possible industrially with an easy access to them. From this, it can be seen that department stores were mediators of trends and the epicenter of popularizing exotic tastes.

• Journal of the Korean Geotechnical Society
• /
• v.24 no.9
• /
• pp.33-40
• /
• 2008

This paper describes the performance of ground improvement project using prefabricated vertical drains of condition, in which approximately 10m dredged fill overlies original soft foundation layer in the coastal area composed of soft marine clay with high water content and high compressibility. From field monitoring results, excessive ground settlement compared with predicted settlement in design stage developed during the following one year. In order to predict the final consolidation behavior, recalculation of consolidation settlements and back analysis using observed settlements were conducted. Field monitoring results of surface settlements were evaluated, and then corrected because large shear deformation occurred by construction events in the early stages of consolidation. To predict the consolidation behavior, material functions and in-situ conditions from laboratory consolidation test were re-analyzed. Using these results, height of additional embankment is estimated to satisfy residual settlement limit and maintain an adequate ground elevation. The recalculated time-settlement curve has been compared with field monitoring results after additional surcharge was applied. It might be used for verification of recalculated results.

• International Journal of Computer Science & Network Security
• /
• v.23 no.4
• /
• pp.1-6
• /
• 2023

Morphological analysis is a branch of natural language processing, is now a rapidly growing field. The fundamental tenet of morphological analysis is that it can establish the roots or stems of words and enable comparison to the original term. Arabic is a highly inflected and derivational language and it has a strong structure. Each root or stem can have a large number of affixes attached to it due to the non-concatenative nature of Arabic morphology, increasing the number of possible inflected words that can be created. Accurate verb recognition and extraction are necessary nearly all issues in well-known study topics include Web Search, Information Retrieval, Machine Translation, Question Answering and so forth. in this work we have designed and implemented an algorithm to detect and recognize Arbic Verbs from Arabic text.The suggested technique was created with "Python" and the "pyqt5" visual package, allowing for quick modification and easy addition of new patterns. We employed 17 alternative patterns to represent all verbs in terms of singular, plural, masculine, and feminine pronouns as well as past, present, and imperative verb tenses. All of the verbs that matched these patterns were used when a verb has a root, and the outcomes were reliable. The approach is able to recognize all verbs with the same structure without requiring any alterations to the code or design. The verbs that are not recognized by our method have no antecedents in the Arabic roots. According to our work, the strategy can rapidly and precisely identify verbs with roots, but it cannot be used to identify verbs that are not in the Arabic language. We advise employing a hybrid approach that combines many principles as a result.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.25 no.2
• /
• pp.1-16
• /
• 2023

Due to the current seriousness of environmental pollution and the eco-friendly movement of the fashion industry, research on sustainable fashion design is being actively conducted. In this study, consumer perception of upcycling products, are divided into image, function, and meaning; and image is further divided into shape, color, and material. It was redefined as pattern, and image recognition was evaluated among men and women in their 20s and 30s, and men and women in their 40s and 50s used as subjects. First, factors that determine each image were extracted based on qualitative analysis of the precedent cases of upcycling bags, and quantitative analysis of the subjects was induced through a questionnaire. As a result of the analysis of evaluation items related to image association, the average frequency analysis of all subjects for each stimuli and the cognitive variance of the frequency analysis by generation by gender were found to be similar. However, awareness of some stimuli by generation showed a significant difference. Overall, in the three stimuli with high overall preference, common features, such as the basic box-shaped symmetrical structure, the monochromatic color of the Munsell system, solid and practical texture, and appropriate use of patterns were identified. In addition, it was confirmed that there was a difference with factors such as femininity, simplicity, touch, and splendor in the measurement factors. In conclusion, it is considered that the main significance of this study is that it excluded the recognition and meaning of upcycling products and explored the original design and image elements of products. Therefore, it is expected that this study will be used as a basic data for responding to the gender image of each generation as an alternative method of sustainable fashion design, and it will be an opportunity to expand the scope of the study to a detailed study beyond the biased topic.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.1D
• /
• pp.81-87
• /
• 2006

The rubblization technique is breaking the aged concrete pavement slab into rubblized concrete aggregate, and use it as an base material at its original position, then builds overlay above the rubblized base. This method has been successively used in USA due to the advantage of good constructibility, cost-effectiveness as well as the capability of preventing of reflection cracks. However, constructibility and economic performance of rubblization on typical Korean concrete pavements needed to be investigate since to typical Korean concrete pavements have thick slab, as well include lean concrete subbase course. Multi-head type breaker suitable for Korean condition was designed and developed. This multi-head type breaker was designed to rubblize old concrete to the suggested optimum rubblized-depth and rubblized-concrete-aggregate size to prevent reflection crack and maintain high bearing capacity. This machine was used for the test of rubblization of old concrete pavement on a non-use old concrete and a in-serviced road. In these two tests, engineering properties of rubblized base and constructability and cost were investigated. In both tests, the old concrete rubblized to targeted size and depth, and high-level bearing capacity was achieved. Also, superior constructability and lower cost compared with traditional reconstruction was examined.

• Journal of Advanced Navigation Technology
• /
• v.27 no.5
• /
• pp.621-628
• /
• 2023

This study derived a reverse engineering procedure for verifying the design identity of original parts and developed parts for PMA(Parts Manufacturer Approval) and STC(Supplemental Type Certificate) of metal brake pads for transport aircraft, which are critical parts among aircraft parts and equipment. In Korea, the regulations for reverse engineering procedures are regulated by the Parts Manufacturer Approval Guidelines, and in the United States, AC No. 21. 303-4. In the reverse engineering for the brake pad, the detailed procedures for each component were determined by selecting verification test items to confirm identity based on sample quantity, dimensional tolerance, mechanical property measurement, material, weight and volume characteristics for each component. In addition, as a result of analyzing the regulation of Korea and United States, in the case of Korea, it is necessary to establish technical standards for braking systems for transport aircraft and regulations related to flight tests.

• Resources Recycling
• /
• v.32 no.6
• /
• pp.79-89
• /
• 2023

One of the foremost environmental challenges, alongside the contemporary focus on achieving carbon neutrality, pertains to the pervasive issue of plastic waste. Thermochemical recycling technology, operating under high-temperature conditions to covert organic matter and recycle it into raw materials and energy, represents a transformative approach surpassing the conventional bounds of material recycling predominantly applied in plastic waste management. The thermochemical recycling paradigm is emerging as a pivotal technology within the circular economy, capable of transforming waste plastics into raw materials for producing original plastics. Its significance extends beyond national borders, garnering global attention due to its versatility as a chemical or energy recycling method, contingent upon the subsequent processes and final products. This study aims to scrutinize three quintessential thermochemical recycling technologies: combustion, gasification, and pyrolysis. Furthermore, the study discusses the recent major technology trends of these technologies.