직접 분사식 디젤기관의 연소특성 해석

金良述,韓昇昶 홍익대학교 산업기술연구소 2002 産業技術 Vol.12 No.-

For understanding combustion phenomena in a D.I disel engine, a simulation analysis was mode by using the Star-CD program modified four disel engine. The calculation results were then compared with the experimental results. The effects of the injection nozzle specification, configuration of the combustion chamber and the air motion within the engine performance were investigated.

내연기관 밸브의 응력 해석

金良述,韓昇昶 홍익대학교 산업기술연구소 2003 産業技術 Vol.13 No.-

Numerical analysis of the dynamic contact and the stress developing in the high-speed driven valve of an internal combustion engine is presented. The valve is modeled by finite element techniques, and the dynamic contact between the valve and the valve seat is analyzed by the solution strategies of differential algebraic equations. Also an iterative scheme similar to the augmented Lagrange multiplier method is employed to enforce the contact constraints. It is shown that the contact and separation between the valve and the valve seat can be computed by the finite element techniques without assuming the artificial springs, and the efficiency and accuracy of the solution are demonstrated by the numerical examples.

PDA 밸브에 의한 연소실내의 연소특성에 관한 연구

김대열,한영출,조재명,김양술,주신혁,박병완 한국공작기계학회 2003 한국공작기계학회 추계학술대회논문집 Vol.2003 No.-

An experimental study presents characteristics of combustion in a combustion chamber by port deactivation valve for economy and emissions standards. In order to use combustion properties data, it is necessary to build some data base, which use cylinder pressure sensor, etc. Port deactivation valve has been developed to satisfy requirement of achieving sufficient swirl generation to improve the combustion. A feasibility and necessity of combustion pressure based cylinder spark timing control has been examined. So, this was obtained the Coefficient of Variation(COV) and the mass-burned(MFB). The characteristics of pressure ratio fraction is similar to that of mass-burned fraction. Using the results of the test, the effects of the combustion chamber can be improved combustion stability by port deactivation.

Optimization of Drying Temperature and Time for Pork Jerky Using Response Surface Methodology

Han-Sul Yang,Sung-Won Kang,Jin-Yeon Jeong,Ji-Yeon Chun,Seon-Tea Joo,Gu-Boo Park,Sung-Gil Choi 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.4

Response surface methodology (RSM) was applied to determine the optimum drying conditions for pork jerky. The physicochemical properties of pork jerky, such as final moisture content, water activity (Aw), pH, and shear force were investigated. In addition, sensory characteristics of pork jerky were evaluated and were used as a parameter for determining the optimum condition. Pork jerky samples were dried at different temperatures between 40 to 80℃ for the time ranged from 0 to 10 hr. The predicted values for moisture content, Aw, and shear force of dried pork samples were in good agreement with the experimental values with correlation coefficients (R²) of 0.95, 0.96, and 0.97, respectively. Both drying temperature and time significantly (p<0.01) affected moisture content, Aw, pH, and shear force and their interactions were also significant at p<0.01 except for Aw. RSM showed the optimum drying conditions for pork jerky, based on moisture content, shear force, and sensory evaluation to be 65-70℃ for 7-8 hr.

Physical and Sensory Properties of Low Fat Sausage Amended with Hydrated Oatmeal and Various Meats

Yang, Han-Sul,Kim, Gap-Don,Choi, Sung-Gil,Joo, Seon-Tea Korean Society for Food Science of Animal Resource 2010 한국축산식품학회지 Vol.30 No.3

Low-fat sausages were prepared with various meats to investigate the effect of the addition of oatmeal at 10% as a fat substitute. The sausages were made with beef, pork and chicken after trimming the visible fat, and the physical and sensory properties of the sausages were evaluated. Beef sausage had the lowest cooking yield and the highest hardness, while chicken sausage showed the opposite properties. The addition of oatmeal resulted in sausage products with less cooking loss and softer texture for all types of meat sausages. Such changes were more pronounced for beef low-fat sausage than for the other types of sausages. The results of moisture absorption suggested that the difference in cooking yield and hardness among sausage products was due to the water-retention properties of different meats and the substitute in response to heat treatment. Sensory evaluation indicated that the greatest overall acceptability of the sausage products were obtained from 10% oatmeal-added pork sausage and that the addition of oatmeal led to better acceptability for all types meat sausages.

Effects of Dietary Glycine Betaine on Growth and Pork Quality of Finishing Pigs

Yang, Han Sul,Lee, Jeong Ill,Joo, Seon Tea,Park, Gu Boo Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.5

This study was carried out to compare the growth performance and quality properties of pork from finishing pigs fed different levels of betaine. A total 120 female pigs (Landrace${\times}$Yorkshire${\times}$Duroc) were fed either a control commercial diet or the control diet supplemented with 2, 4 and 6% betaine for 31 days. The average daily feed intake (ADFI) of the 2% diet was lower than of the other treatment groups. The average daily gain (ADG) for pigs fed betaine diets was significantly higher (p<0.05) compared with nonsupplemented diets. Feed conversion ratio (FCR) of pigs fed betaine diets was significantly lower (p<0.05) compared with nonsupplemented diets. pH of loin and ham samples were not significantly different between dietary groups, whereas CIE a* (redness) of pork loin was increased by dietary betaine. Also, the shear force value of loin was significantly higher (p<0.05) in pigs given dietary betaine compared with non-supplemented diets, but no significant differences were found in cooking loss by the loin among diets with different levels of betaine (p>0.05). Dietary supplementation with betaine decreased total cholesterol concentrations in blood, and increased saturated fatty acid and decreased unsaturated fatty acid levels in muscle. Pigs supplemented with betaine had increased betaine concentrations in the loin muscle. It was concluded that dietary betaine supplementation of finishing pigs can improve growth performance and reduce blood cholesterol concentrations. It was also concluded that dietary betaine produced detectable betaine concentrations in the lion muscle.

Effects of Salt Concentration and Drying Time on the Quality Characteristics of Pork Jerky during Dehydration

Yang, Han-Sul,Kang, Sung-Won,Joo, Seon-Tea,Choi, Sung-Gil Korean Society for Food Science of Animal Resource 2012 한국축산식품학회지 Vol.32 No.3

This study was conducted in order to evaluate the effects of brine pre-soaking at different concentrations and drying time on the quality characteristics of pork jerky. The physicochemical properties of pork jerky including final moisture content, water activity ($a_w$), shear force, microstructure, and thiobarbituric acid reactive substance (TBARS) values were investigated. The sensory attributes of pork jerky were evaluated and used as parameters for determining the optimum drying condition. The sliced pork samples were pre-soaked at salt concentrations ranging from 0 to 10% for 3 h and then dried at $70^{\circ}C$ for up to 10 h. The pre-soaked samples in the salt solution showed higher final moisture content than the control sample after drying for 10 h. The final moisture content of pork jerky increased with increasing salt concentrations. On the other hand, the water activity with regards to the pre-soaked samples in a 10% salt solution showed the lowest value for up to 8 h drying. The shear force values of pork jerky decreased with increasing salt concentration while the TBARS values of the samples increased with increasing salt concentrations. Sensory evaluation suggested that the color, flavor, juiciness, and tenderness of the pork jerky samples were improved by pre-soaking in a 2% salt solution and the highest likeability score of pork jerky among the samples were obtained by pre-soaking in a 2% salt solution prior to drying.

Effects of Salt Concentration and Drying Time on the Quality Characteristics of Pork Jerky during Dehydration

Han Sul Yang,Sung Won Kang,Seon Tea Joo,Sung Gil Choi 한국축산식품학회 2012 한국축산식품학회지 Vol.32 No.3

This study was conducted in order to evaluate the effects of brine pre-soaking at different concentrations and drying time on the quality characteristics of pork jerky. The physicochemical properties of pork jerky including final moisture content, water activity (aw), shear force, microstructure, and thiobarbituric acid reactive substance (TBARS) values were investigated. The sensory attributes of pork jerky were evaluated and used as parameters for determining the optimum drying condition. The sliced pork samples were pre-soaked at salt concentrations ranging from 0 to 10% for 3 h and then dried at 70oC for up to 10 h. The pre-soaked samples in the salt solution showed higher final moisture content than the control sample after drying for 10 h. The final moisture content of pork jerky increased with increasing salt concentrations. On the other hand, the water activity with regards to the pre-soaked samples in a 10% salt solution showed the lowest value for up to 8 h drying. The shear force values of pork jerky decreased with increasing salt concentration while the TBARS values of the samples increased with increasing salt concentrations. Sensory evaluation suggested that the color, flavor, juiciness, and tenderness of the pork jerky samples were improved by pre-soaking in a 2% salt solution and the highest likeability score of pork jerky among the samples were obtained by pre-soaking in a 2% salt solution prior to drying.

Optimization of Drying Temperature and Time for Processing of Pork Jerky Using Response Surface Methodology

Yang. Han-Sul,Jeong. Jin-Yeon,Choi. Sung-Gil,Joo. Seon-Tea,Park. Gu-Boo 한국축산식품학회 2006 심포지움 및 학술발표회 Vol.- No.37

Physical and Sensory Properties of Low Fat Sausage Amended with Hydrated Oatmeal and Various Meats

Han Sul Yang,Gap Don Kim,Sung Gil Choi,Seon Tea Joo 한국축산식품학회 2010 한국축산식품학회지 Vol.30 No.3

Low-fat sausages were prepared with various meats to investigate the effect of the addition of oatmeal at 10% as a fat substitute. The sausages were made with beef, pork and chicken after trimming the visible fat, and the physical and sensory properties of the sausages were evaluated. Beef sausage had the lowest cooking yield and the highest hardness, while chicken sausage showed the opposite properties. The addition of oatmeal resulted in sausage products with less cooking loss and softer texture for all types of meat sausages. Such changes were more pronounced for beef low-fat sausage than for the other types of sausages. The results of moisture absorption suggested that the difference in cooking yield and hardness among sausage products was due to the water-retention properties of different meats and the substitute in response to heat treatment. Sensory evaluation indicated that the greatest overall acceptability of the sausage products were obtained from 10% oatmeal-added pork sausage and that the addition of oatmeal led to better acceptability for all types meat sausages.