• Economic and Environmental Geology
• /
• v.46 no.4
• /
• pp.279-289
• /
• 2013

The most critical factor in developing coalbed methane(CBM) reservoir is absolute permeability. Both productivity and economics of the CBM depend on the absolute permeability. The methods to estimate it are core analysis and well test. However, absolute permeability determined by core analysis cannot be a good representative of CBM reservoir. Therefore, it is generally estimated by well test. In this study, well test methods applicable of CBM reservoir were classified with their characteristics. Merits and demerits of each well tests were also analyzed. Based on those parameters, design considerations and procedures of well test were derived. After each well tests was performed, the procedure of well test interpretations to estimate reservoir properties such as absolute permeability and skin factor was presented.

• Journal of the Korean Institute of Gas
• /
• v.23 no.3
• /
• pp.7-19
• /
• 2019

In this study, a model was developed for estimating deliverability considering the pressure dependent permeability and predicting production profile with Material Balance Equation(MBE) for Coalbed Methane(CBM) fields. The estimated deliverability was compared with the conventional deliverability based on CBM well testing data with coefficient of determination($R^2$). As a result, the former was 0.76 and the latter was 0.69. It was confirmed that the deliverability which consider the pressure dependent permeability is more adoptable when representing the productivity of CBM fields. Through this process, in order to calculate pressure dependent permeability when well testing data exist, a method to infer reservoir pressure within the radius of investigation was proposed. The production profile of 31 gas wells was predicted for 15 years, using the estimated deliverability and the MBE. After that, the results was compared with simulation results of the literature. The simulation results did not account the pressure dependent permeability and the developed model results considered that. As the applied field permeability rised 1.17 times, field production rate was increased approximately 15% than the literature results. According to other researches, the permeability of CBM fields can be rise 6 ~ 25 times. For these cases, the production profiles may have significant difference with conventional gas fields.

• KSBB Journal
• /
• v.20 no.1 s.90
• /
• pp.55-59
• /
• 2005

Toxicity test for biodiesel (BD), biodiesel-derived neopentyl polyol ester (NPE) lubricant oil base, lubricant oil for diesel engine (LODE) and petroleum diesel (PD) was carried out using microalgae, Chlorella vulgaris. According to the method of OECD 201, the $EC_{50}$ values of BD and NPE were estimated as 84 and 69 mg/L, respectively, which indicates that these compounds are classified as slightly toxic compounds. The $EC_{50}$ values of LODE and PD were measured as 42 and 24 mg/mL, respectively, showing that these compounds are considered as moderately toxic compounds.

• Journal of Nutrition and Health
• /
• v.13 no.4
• /
• pp.199-206
• /
• 1980

Formulation and production performance of proposed high nutriton-low cost (HNLC) supplementary foods for children in Korea were studied for Wonseong County Comprehensive Nutrition Program. The basic formulas recommendable from the experimental results on the nutritional value, organoleptical qualities and mechanical performance using MFM-KIST extrusion cooking system were considered as CSS-3, CSS-4 and BSS-4. Initial priority of application soybean was with CSS-4(68% corn flour, defatted soybean flour 20%, sesame 2%, corn oil 4%, sugar 4%, salt 1%, vitamins, mineral and other additives 1%). All these formulas as on rioted snack type-HNLC supplementary foods were found in the acceptable range of mechanical, organoleptical and economical point of view.

• Korean Journal of Poultry Science
• /
• v.38 no.4
• /
• pp.331-338
• /
• 2011

The study was conducted to evaluate the production and the performance test of egg-type commercial Korean Native Chickens. A total of 360 female layers were produced from CY${\times}$C (A), CL${\times}$C (B), CG${\times}$C (C) and CW${\times}$C (D) crossbreds kept at National Institute of Animal Science, Korea, and breed during 20~64 weeks to investigate the productivity and the performance. Layers were divided into 4 crossbreds (6 replications/crossbred, 15 heads/replication). Age and egg weight at first egg was no significantly different among crossbreds. Body weight (BW) at first egg of D crossbred was significantly lower compared to that of other crossbreds (P<0.05). Weekly BW of B crossbred was the highest at 20, 30 and 40 weeks of age, but BW of D crossbred was the lowest among crossbreds. Feed intake (FI) of B crossbred was significantly higher compared to the other crossbreds at 20~24, 32~44 and 52~60 weeks of age. FI of D crossbred was significantly lower compared to other crossbreds after the age of 44 weeks (P<0.05). Average egg weight of B crossbred was significantly higher than the other crossbreds at the age of 24~60 weeks (P<0.05). Egg production ratio (%) of C crossbred was significantly higher compared to the other crossbreds for whole test periods (P<0.05). Hen-housed egg production number at 64 weeks of age for A, B, C and D crossbreds resulted in 241.4, 235.6, 232.3 and 227.0, respectively. Feed conversion ratio of A and C crossbreds was lower compared to the other crossbreds at the age of 20~24 weeks and C crossbred was the lowest among the crossbreds at the age of 60~64 weeks. These results provide the basic data which will be helpful to develope the new strains of commercial Korean Native Chickens.

• KSBB Journal
• /
• v.20 no.2 s.91
• /
• pp.84-87
• /
• 2005

Toxicity test for biodiesel (BD), biodiesel-derived neopentyl polyol ester (NPE) lubricant oil base, lubricant oil for diesel engine oil (LODE) and petroleum diesel (PD) was carried out using earthworm, Eisenia fefida. According to the method by OECD 207, the $LC_{50}$ values of BD and NPE were estimated as 2,450 and 1,528 mg/kg, respectively, which indicate that these compounds are classified as slightly toxic compounds. The $LC_{50}$ values of LODE and PD were estimated as 500 and 603mg/kg, respectively, showing that theses compounds are evaluated as moderately toxic compounds.

• Journal of the Korean Institute of Gas
• /
• v.28 no.2
• /
• pp.66-75
• /
• 2024

This paper presents development of a CO₂ injectivity analysis model using nodal analysis for the depleted oil reservoirs in Malaysia. Based on the final well report of an appraisal well, a basic model was established, and sensitivity analysis was performed on injection pressure, tubing size, reservoir pressure, reservoir permeability, and thickness. Utilizing the well testing report of A appraisal well, permeability of 10md was determined through production nodal analysis. Using the basic input data from the A appraisal well, an injection well model was set. Nodal analysis of the basic model, at the bottomhole pressure of 3000.74psia, estimated the CO₂ injection rate to be 13.29MMscfd. As the results of sensitivity analysis, the injection pressure, reservoir thickness, and permeability tend to exhibit a roughly linear increase in injection rate when they were higher, while a decrease in reservoir pressure at injection also resulted in an approximate linear increase in injection rate. Analyzing the injection rate per inch of tubing size, the optimal tubing size of 2.548inch was determined. It is recommended that if the formation parting pressure is known, performing nodal analysis can predict the maximum reservoir pressure and injection pressure by comparing with bottomhole pressure.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.6
• /
• pp.729-738
• /
• 1997

To estimate the change in rice productivity around lake Juam due to construction of artificial lake, growth, yield components and yield of rice were measured at different locations around lake Juam for three years from 1994 to 1996. Automated weather stations(AWS) were installed nearby the experimental paddy fields, and daily maximum, average and minimum temperature, solar radiation, relative humidity, and precipitation were measured for the whole growing period of rice. Plant height, number of tillers, leaf area and shoot dry weight per hill were observed from 8 to 10 times in the interval of 7 days after transplanting. Yield and yield components of rice were observed at the harvest time. Simulation model of rice productivity used in the study was SIMRIW developed by Horie. The observed data of rice at 5 locations in 1994, 3 locations in 1995 and 4 locations in 1996 were inputted in the model to estimate the unknown parameters. Comparisons between observed and predicted values of shoot dry weights, leaf area indices, and rough rice yield were fairly well, so that SIMRIW appeared to predict relatively well the variations in productivity due to variations of climatic factors in the habitat. Climatic elements prior to as well as posterior to dam construction were generated at six locatons around lake Juam for thirty years by the method of Pickering et al. Climatic elements simulated in the study were daily maximum and minimum temperature, and amount of daily solar radiation. The change in rice productivity around lake Juam due to dam construction were estimated by inputting the generated climatic elements into SIMRIW. Average daily maximum temperature after dam construction appeared to be more or less lower than that before dam construction, while average daily minimum temperature became higher after dam construction. Average amount of daily solar radiation became lower with 0.9 MJ $d^{-1}$ after dam construction. As a result of simulation, the average productivity of habitats around lake Juam decreased about 5.6% by the construction of dam.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.31 no.4
• /
• pp.454-464
• /
• 1986

To find main factors to affect tobacco culture and quality, NC 2326 (Nicotiana tabacum L.) was cultivated in Korea and in the United States under different plant density, fertilization, mulching and curing. Among the chemical characteristics of the both experimental soils, the organic matters were similar concentration in both locations but effective phosphorous contents were higher in Oxford in the United States. Plant height, length and width of the largest leaf, leaf thickness, and midrib ratios were larger in Oxford than in Suwon in Korea. Also they were larger in non mulching system than in mulching system. But the total numbers of the leaves were decreased in non mulching system. The content of nicotine was higher in the plant grown in Suwon than in Oxford. The concentrations of nicotine and sugar tend to increase in mulching system comparing of non mulching system. During the growing, the concentration of non-volatile organic acids was higher in Suwon, while it was lower in cured leaf produced in Suwon. Also the contents of total fatty acids were lower in the harvested leaf grown in Suwon, but not in cured tobacco. Forty three compounds identified among the volatile oils from these experimental samples were quantified. The concentrations of the major components related to the tobacco flavour such as damascone, damascenone, solanone, nor-solanadione, and megastigmatrienones were higher in the cured tobacco produced in Oxford rather than in Suwon.

• Composites Research
• /
• v.34 no.4
• /
• pp.241-248
• /
• 2021

As the electric vehicle market grows, there is an issue of light weight vehicles to increase battery efficiency. Therefore, it is going to replace the battery module cover that protects the battery module of electric vehicles with high strength/high heat-resistant polymer composite material which has lighter weight from existing aluminum materials. It also aims to respond to the early electric vehicle market where technology changes quickly by combining 3D printing technology that is advantageous for small production of multiple varieties without restrictions on complex shapes. Based on the composite material mechanics, the critical length of glass fibers in short glass fiber (GF)/polycarbonate (PC) composite materials manufactured through extruder was derived as 453.87 ㎛, and the side feeding method was adopted to improve the residual fiber length from 365.87 ㎛ and to increase a dispersibility. Thus, the optimal properties of tensile strength 135 MPa and Young's modulus 7.8 MPa were implemented as GF/PC composite materials containing 30 wt% of GF. In addition, the filament extrusion conditions (temperature, extrusion speed) were optimized to meet the commercial filament specification of 1.75 mm thickness and 0.05 mm standard deviation. Through manufactured filaments, 3D printing process conditions (temperature, printing speed) were optimized by multi-optimization that minimize porosity, maximize tensile strength, and printing speed to increase the productivity. Through this procedure, tensile strength and elastic modulus were improved 11%, 56% respectively. Also, by post-processing, tensile strength and Young's modulus were improved 5%, 18% respectively. Lastly, using the FEA (finite element analysis) technique, the structure of the battery module cover was optimized to meet the mechanical shock test criteria of the electric vehicle battery module cover (ISO-12405), and it is satisfied the battery cover mechanical shock test while achieving 37% lighter weight compared to aluminum battery module cover. Based on this research, it is expected that 3D printing technology of polymer composite materials can be used in various fields in the future.