• Journal of Life Science
• /
• v.34 no.10
• /
• pp.682-690
• /
• 2024

This study aimed to produce medium-chain-length polyhydroxyalkanoates (mcl-PHA) using oil extracted from spent coffee grounds (SCG) as a carbon source. The highest oil yields, 14.40%(w/w) and 14.49%(w/w), were achieved with an extraction time of 2 hr and an SCG/n-hexane ratio of 15:1. The fatty acid composition of the extracted SCG oil (EOC) primarily consisted of linoleic acid (45.08%), palmitic acid (35.56%), oleic acid (8.62%), and stearic acid (7.62%). Pseudomonas sp. HY61, isolated from soil, was used to biosynthesize mcl-PHA composed of 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and 3-hydroxydodecanoate using EOC. Under optimal flask conditions, the highest cell growth and mcl-PHA accumulation were observed with 5 g/l EOC, 72 hr, with NH₄Cl as the nitrogen source, at pH 7, 25℃, and a C/N ratio of 15:1. Batch fermentation resulted in a dry cell weight (DCW) of 0.92 g/l and mcl-PHA of 0.17 g/l after 72 hr. In contrast, fed-batch fermentation, with additional supplementation of EOC and NH₄Cl at 18, 30, and 42 hr, increased the DCW to 2.85 g/l and mcl-PHA accumulation to 0.67 g/l, approximately three times higher than batch fermentation. Gas chromatography confirmed that the mcl-PHA structure was consistent across both fermentation modes. The synthesized mcl-PHA had higher molecular weight and thermal decomposition temperatures compared to other mcl-PHA, suggesting its potential applications in packaging and biomedical fields. This study offers an economical approach for mcl-PHA production using waste EOC and Pseudomonas sp. HY61.

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.6
• /
• pp.701-717
• /
• 2003

The objective of this study was to extensively estimate the air quality trends of the study area by surveying con-centration trends in months or seasons, after analyzing the mass concentration of PM-10 samples and the inorganic lements, ion, and total carbon in PM-10. Also, the study introduced to apply the PMF (Positive Matrix Factoriza-tion) model that is useful when absence of the source profile. Thus the model was thought to be suitable in Korea that often has few information about pollution sources. After obtaining results from the PMF modeling, the existing sources at the study area were qualitatively identified The PM-10 particles collected on quartz fiber filters by a PM-10 high-vol air sampler for 3 years (Mar. 1999∼Dec.2001) in Kyung Hee University. The 25 chemical species (Al, Mn, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, Pb, Si, N $a^{#}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$, C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, TC) were analyzed by ICP-AES, IC, and EA after executing proper pre - treatments of each sample filter. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols. the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided source profiles (scaled F matrix). So, 11 sources were qualitatively identified, such as secondary aerosol related source, soil related source, waste incineration source, field burning source, fossil fuel combustion source, industry related source, motor vehicle source, oil/coal combustion source, non-ferrous metal source, and aged sea- salt source, respectively.ively.y.

• Applied Chemistry for Engineering
• /
• v.21 no.4
• /
• pp.372-376
• /
• 2010

Non-conventional energy is considered as important future energy source, as conventional energy has limitation for its capacity. The demand on value added process in heavy oil/oil sand bitumen is increasing in particular. Solvent Deasphalting (SDA) process for Deasphalted Oil (DAO) is used as heavy oil upgrading process in existing refinery process. SDA process for heavy oil upgrading has been already commercialized by leading countries. SDA R&D projects have been carried out actively by those countries. In this study, patent analysis for SDA technology development was carried out. From 1970's, when SDA patents were applied, the patents in Korea, USA, Japan, Canada and Europe were searched and distributed to extraction, recovery, solvent and etc. 334 patents were selected relating to heavy oil upgrading SDA process. The application status of SDA process patents showed a tendency to increase slightly. The number of patent applied was USA patent 131 (39%), Canada patent 83 (25%), Japan patent 35 (11%) and Korea patent 6 (2%). It will be necessary for efficient use of energy resource to support SDA R&D by government.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.8
• /
• pp.1180-1185
• /
• 2009

Two experiments were carried out to study the effects of dietary energy level on nutrient digestion, nitrogen (N) utilization, growth performance, insulin-like growth factor-I (IGF-I), and insulin-like growth factor binding protein-3 (IGFBP-3) in plasma, liver and longissimus dorsi muscle in growing-finishing pigs. In experiment 1 (Exp 1), 15 castrated male pigs (Duroc${\times}$Landrace${\times}$Large White) (Body weight, BW, 55.6${\pm}$1.8 kg) were divided into three groups and fed rations containing 13.33, 14.87 and 17.35 MJ digestible energy (DE)/kg as treatments I, II and III, respectively, using soybean oil as an energy source. The experiment lasted 8 days and faecal and urinary samples were collected during the last 3 days. The results showed that the digestibility of dry matter (DM), energy and N was increased from treatments I to III (p<0.01). N-retention and N-retention rate were not influenced by dietary DE level (p>0.05). In experiment 2 (Exp 2), 36 female pigs (Duroc${\times}$Landrace${\times}$Large White) (BW 41.5${\pm}$3.8 kg) were divided into three groups. The pigs were fed with the same three rations used in Exp 1 for 60 days. At the end of Exp 2, eight pigs were selected from each group for blood sampling and 4 pigs for slaughter trial. The results indicated that average daily feed intake (ADFI) and N-intake were significantly decreased (p<0.01), and DE intake (p<0.01) and average daily gain (ADG) (p<0.05) were increased. IGF-I and IGFBP-3 in plasma were increased (p<0.05). No significant differences in IGF-I and IGFBP-3 in liver and longissimus dorsi muscle were found between different treatments. It was concluded that higher dietary DE level improved nutrient digestibility, ADG and feed/gain ratio when soybean oil was used as an energy source in the ration of growing-finishing pigs. No significant differences were found in Nretention and IGF-I and IGFBP-3 in liver and longissimus dorsi muscle between different treatments.

• Animal Bioscience
• /
• v.35 no.1
• /
• pp.54-63
• /
• 2022

Objective: This study aimed to evaluate the replacement of degummed soybean oil (DSO) by acid soybean oil (ASO) in diets with or without the inclusion of emulsifier on broiler performance, relative organ weight, lipase activity, intestinal morphometry, and nutrient digestibility. Methods: A total of 704 1-day-old male broiler chicks were allotted to a 2×2 completely randomized factorial design (with or without emulsifier × two lipid sources [ASO and DSO]), with eight replicates and 22 birds each. The metabolizable energy level in diets with emulsifier was reduced by 40 kcal/kg from 1 to 21 d and 50 kcal/kg from 22 to 49 d. Results: Broilers fed diets containing ASO without emulsifier had higher (p = 0.005) weight gain than DSO-fed animals and with the inclusion of emulsifier had worse (p = 0.018) feed conversion ratio (FCR). Birds fed diets with emulsifier worsened FCR regardless of lipid source from 1 to 21 days (p = 0.006) and from 1 to 49 days (p = 0.0002). There was an increase (p = 0.026) in the relative pancreas weight, at 14 days, in birds fed diets containing ASO. Lipase activity and morphometry of the duodenum and jejunum, at 14 and 21 days, were not affected (p>0.05). The dietary inclusion of emulsifier improved the digestible energy (p = 0.053) in the presence of ASO. For the digestibility coefficients (gross energy, crude protein, and mineral matter), no interference was observed (p>0.05). Conclusion: The inclusion of emulsifier to energy-restricted diet with ASO maintained broiler performance in the first week, but worsened FCR in subsequent phases. The ASO can be considered as an alternative lipid source to DSO and does not interfere with the morphophysiological characteristics and performance of broilers. The combination of ASO and emulsifier increased the digestible energy content by 6.2%.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.652-655
• /
• 2005

Considering the fact that more than $97\%$ of fossil energy resources such as oil and natural gas needed in Korea rely on import, primary concern of the national economy is to secure future energy sources. Gas hydrates. which is non-conventional types of natural gas, distribute worldwide, especially in marine and permafrost Gas hydrates draw great attention recently as a new clean energy resources substituting conventional oil gas due to its presumed huge amount of volume reaching 10 trillion tons of gas and environmentally friendly characteristics. Results of preliminary survey by Korea Gas Corporation (KOGAS) and Korea Institute of Geoscience and Mineral Resources (KIGAM) showed that gas hydrates can be present in deep sea over 1,000m water depth in the East Sea. Gas hydrates can contribute to the rapidly increasing consumption of natural gas in Korea and achieve the self-support target by 2010 with $30\%$ of total natural gas demand. This study presents the potentialities and development prospects of gas hydrate as a future energy source.

• Journal of Environmental Science International
• /
• v.13 no.7
• /
• pp.703-710
• /
• 2004

Petroleum refineries have been considered as an important emission source for atmospheric volatile hazardous air pollutants(HAPs). The emission source includes petroleum refinery processes and process equipment. The control strategy for volatile HAPs requires emission estimations of these pollutants. However, systematic methods of volatile HAPs emission from petroleum refineries have not yet been established. Accordingly, present study surveyed the estimation method of volatile HAPs emitted from the petroleum refinery processes and process equipment. The emission estimation methods for the petroleum refinery processes are applied for 11 petroleum refining facilities: fluidized catalytic cracking, thermal cracking, moving bed catalytic cracking, compressed engine, blowdown system, vacuum distilled column condensator, natural gas or distilled boiler, natural gas or distilled heater, oil boiler, oil heater and flare. Four emission estimation methods applied for the petroleum refinery process equipment are as follows: average emission factor approach, screening ranges approach, EPA correlation approach and unit-specific correlation approach. The process equipment for which emission factors are available are valves, pump seals, connectors, flanges and open-ended lines.

• Fisheries and Aquatic Sciences
• /
• v.11 no.3
• /
• pp.149-158
• /
• 2008

Labyrinthulids are unicellular heterotrophic marine microalgae. Two labyrinthulid strains, L4 and L75, which produce generous amounts of polyunsaturated fatty acids(PUFAs), were isolated from leaves floating in the coastal areas of Quang Ninh province, Vietnam, and Fukuoka Prefecture, Japan, respectively. Both strains had spindle-shaped cells surrounded by ectoplasmic networks. Numerous oil bodies were observed in each cell, mostly in the vicinity of cell membranes. When soybean oil or soybean lecithin was used as a carbon source with peptone as a nitrogen source, the proportion of PUFAs reached 25-30% and 50-56% for L4 and L75, respectively. After 14 days of growth at $25^{\circ}C$, L4 produced 0.3 mg PUFAs/g-agar in PYA-SBO medium and 0.6 mg PUFAs/g-agar in PYA-SBL medium. In comparison, L75 produced 0.2 mg PUFAs/g-agar in both types of media. The differences between the two strains included changes in cellular morphology and the capacity for attaching tightly to fibers when cultured in liquid PYA medium containing 2% SBL. In addition, when the strains were grown under the same conditions, L4 had a higher growth rate and produced more PUFAs than L75.

• Journal of Dairy Science and Biotechnology
• /
• v.17 no.1
• /
• pp.16-31
• /
• 1999

Milk and milk products, especially the cow's milk and cheese, have been used since the ancient time. Because they contains almost all kinds of nutrients that are necessary for human beings except for iron, n-3 fatty acid, and vitamin C. Milk is an excellent dietary source of protein, calcium and phosphorus. The biological value of milk protein is as high as those of red meat and eggs. So cheese, a food processed from concentrated milk protein, is highly recommended food for the patient of diabetes mellitus. Because the major form of milk lipids is n-6 fatty acid, milk and milk products may not be a good food for the patients of cardiovascular disease. But the nutritional quality of milk lipids cannot be inferior to those of margarine, fish oil, and vegetable oil. Milk has been produced commercially since 1936 in Korea. The most popular milk product is a drink milk now in Korea. But according to the change of dietary pattern the consumption of yoghurt and cheese has been enormously increased during the last 20 years. As the soy sauce, tofu, and soy been paste have been the fundamental seasoning and source of protein in Korea, milk and cheese have consisted the essential flavor of western cuisine. But the basic idea for the usage of protein, peptides, and amino acids are the same. We found that milk and milk products can be nicely added in many Korean dishes such as Juk, Mandoo, Jeon, and Bindeatuk for the diversity of traditional flavor.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1530-1533
• /
• 2005

Total 12 units of high power klystron-modulator systems as microwave source is under operation for 2.5-GeV electron linear accelerator in Pohang Light Source(PLS) linac. RF power and beam power of klystron are precisely measured for the effective control of electron beam. A precise measurement and measurement equipment with good response characteristics are required for this. Input power of klystron is calculated from the applied voltage and the current on its cathode. Tiny measurement error severely effects RF output power value of klystron. Therefore, special care is needed to measure precise beam voltage. Capacitive voltage divider(CVD) unit is intended for the measurement of beam voltage of 400 kV generated from the pulsed klystron-modulator system. Main parameter to determine the standard capacitance in the high arm of CVD is dielectric constant of insulation oil. Therefore CVD should be designed to have a minimum capacitance variation due to voltage, frequency and temperature in the measurement range. This paper will discuss the analysis of capacitive voltage divider for a pulsed high-voltage measurement, and the empirical relations between capacitance and oil temperature variation.