• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.1
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• pp.17-24
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• 2004

The starter of the turbo generator is composed of a high speed generator(HSG), an inverter and a boost converter instead of a gearbox, a DC motor and a low-voltage battery in the starter of the turbo shaft generation system. Because turbo generator is needed a high speed motoring at start-up, high speed generator has a low leakage inductance and inverter need a high DC link voltage. In this study, for developing the stater of a turbo generator, a boost converter with a high capacity was developed to convert high voltage from a low battery voltage. And for controlling a high frequency current to be injected to a motor winding with a low leakage inductance, the inverter with a high precision and a high speed operation was designed and for a stable ignition, the starting algorithm of a turbo generator was proposed. Turbo generator was started by the starter developed to verify the performances.

• Journal of the Korean Society of Food Culture
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• v.28 no.4
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• pp.401-408
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• 2013

The objective of this study was to determine the quality characteristics of cabbage juice fermented by lactic acid bacteria from Kimchi (Leuconostoc mesenteroides, Lactobacillus sakei SL1103, Lactobacillus plantarum LS5, and mixed starter). Cabbage juice was inoculated with lactic acid bacteria and fermented at 30 for 72 hrs. Changes in lactic acid bacteria number, pH, titratable acidity, Brix, and color during fermentation were analyzed. After fermentation for 24 hrs, cabbage juice fermented by mixed starter showed the highest number of lactic acid bacteria (9.45 log CFU/mL). The pH of all cabbage juice also decreased to 3.88~4.19 sharply, while cabbage juice fermented by Lac. sakei SL1103 showed the highest Brix ($8.38^{\circ}Bx$). Cabbage juice fermented by mixed starter showed the highest L value (56.83). In the sensory evaluation, cabbage juice fermented by a mixed starter (Leu. mesenteroides, Lac. sakei SL1103, and Lac. plantarum LS5) showed the highest preferences in taste, flavor, and overall acceptability. Therefore, cabbage juice fermented by mixed starter (Leu. mesenteroides, Lac. sakei SL1103 and Lac. plantarum LS5) has the highest potential for the development of fermented cabbage juice as an excellent bioactive functional food.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.193-199
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• 2001

Twenty-four new born crossbred (Bos indicus$\times$Bos taurus) calves were distributed in two equal groups and assigned to two different pre-starter diets with (Group 1) and without (Group 2) fish meal to study the effect of replacement of animal protein by vegetable protein in the diet and the age of animals on ruminal metabolic development. All calves were fed colostrum for 24 h and whole milk until weaning at 8 weeks of age. Rumen fluid samples were collected on 4 d, 1 wk, and then weekly interval up to 8 wk of age. Rumen fluid samples were analysed for pH, TVFA, lactic acid and N fractions (total N, total soluble N, trichloro acetic acid (TCA) soluble N, TCA precipitable N and ammonia N). Weekly feed intake and live weight gain pattern showed an increasing trend with the advancement of age, but were similar in both groups. The pH fell steadily during 0-4 wk of age and then stabilized in later period. A close relationship (r=0.80) between starter intake and TVFA concentration was observed in both the groups. Lactic acid (meq/l) and ammonia N (mg/dl) concentration showed initial rise (0.55 and 14.97 on day 4 to 3.38 (7 wk) and 32.85 (4 wk), respectively) to fall (2.74 and 17.60) again during 8 wk of age in response to increase in dry feed consumption (10% initially to 83% of diet dry matter at 8 wk of age). The TCA precipitable fraction of N did not show any change during 0-8 wk of age. Data indicate that the metabolic changes responded rapidly to dry feed intake which did not differ in fish meal and non-fish meal groups, and a poor voluntary consumption of oat hay retards the progressive changes in live weight and rumen microbial development.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.653-656
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• 2002

This paper presents the development of 15G(Integrate Starter Generator). The ISG is the crank shaft mount type and it is installed at tile flywheel. The wide operating range of ISG requires large constant power speed ratio, good overload performance and high efficiency. High saliency ratio permanent magnet motor is developed for the ISG applications and 500A MOSFET inverter is designed to derive the ISG. The characteristic of developed ISG is investigated using the special test-bed for the 42V PowerNet and the detailed results is presented

• Microbiology and Biotechnology Letters
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• v.10 no.3
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• pp.217-222
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• 1982

A lactic starter organism, Lactobaciilus casei YIT 9018 was treated with N-methyl-N'-nitro-N-nitrosoguanidine (NTG) to obtain phage-resistant mutants. Freshly grown cells suspended in citrate buffer were exposed to NTG of 50 g/$m\ell$ for 40 min. Among 88 colonies isolated eight colonies showed distinct resistance to phages isolated previously from milk plants. The eight new colonies showed character similar to the original L. casei except that they responded differently to phage of different sources and thus were designated as eight different mutants of L casei. From the phage resisting toaether with the fermentative ability equivalent to the mother organism the mutants may be considered to be used as starter cultures for fermented milk.

• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1758-1764
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• 2007

Synthesis of oligosaccharides during milk fermentation was attempted by inoculating Leuconostoc citreum with Lactobacillus casei, Lb. delbrueckii subsp. bulgaricus, and Streptococcus thermophilus as starters. Dextransucrase of Ln. citreum worked as a catalyst for the transglycosylation reaction of sugars; sucrose was added as the glucose donor, and lactose or maltose acted as the acceptor compound for the reaction. When 4% sucrose was added in milk, glucosyl-lactose was synthesized (about 1%, w/v) after 1-2 days of fermentation at 15 or $25^{\circ}C$. Alternatively, when sucrose and maltose (2% each, w/v) were added, panose (about 1 %, w/v) and other isomaltooligosaccharides were made in a day at $15-35^{\circ}C$. Growth patterns of lactobacilli and streptococci starters were not affected by the coculture of leuconostoc starter, but the rate of acid synthesis was slightly slowed at every temperature. Addition of sugars in milk did not give any adverse effect on the lactate fermentation. Accordingly, the use of leuconostoc starter and addition of sugars in milk allowed the production of oligosaccharides-containing fermented milk, and application of this method will facilitate the extensive development of synbiotic lactate foods.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.1
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• pp.35-41
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• 2013

Torque characteristics of a turbopump turbine was analyzed using the turbine performance test result. Specific torque of the subject turbine could be expressed as a linear function of corrected rotor speed at a fixed pressure ratio and it has been confirmed by the test result. It also found that corrected rotor speed-specific torque characteristics does not change anymore if the turbine pressure ratio is set bigger than a certain value. Using the turbine torque characteristics and pyro-starter performance test results, rotational speed development behavior of the turbopump was predicted. Prediction revealed that the lap time reaching 50% of turbopump design speed is less than 0.7 second. Effect of the thermal loss between pyro-starter and turbopump was negligible.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.4-10
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• 2012

Torque characteristics of a 75-tonf turbopump turbine was analyzed using the turbine performance test result. Specific torque of the subject turbine could be expressed as a linear function of corrected rotor speed at a fixed pressure ratio and it has been confirmed by the test result. It also found that corrected rotor speed-specific torque characteristics does not change anymore if the turbine pressure ratio is set bigger than a certain value. Using the turbine torque characteristics and pyro-starter performance test results, rotational speed development behavior of the turbopump was predicted. Prediction revealed that the lap time reaching 50% of turbopump design speed is less than 0.7 second. Effect of the thermal loss between pyro-starter and turbopump was negligible.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.2
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• pp.69-75
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• 2017

The gas turbine static starter rotates the stationary synchronous machine by the interaction of the rotor and the stator. The detection from the initial position of the rotor has been an important issue to drive with optimum torque. Previously, the gas turbine starter was used by attaching the encoder to the synchronous machine, but the position and velocity of the rotor have been estimated by sensor-less method until recently due to the difficulty in attaching and detaching and damage caused by the shaft voltage noise. In this paper, Rotor initial(stationary state) position estimation, forced commutation control(speed less than 10%), and natural commutation control(speed more than 10%) method using magnetic flux with integrated terminal voltage were presented and the sensor-less speed control performance was verified. As a result of making and evaluating the 29 kVA synchronous machine and the starting device, the performance of each control mode was satisfactory. Furthermore, the applied technology is expected to be used for the development of the gas turbine starter of tens of MW class and the field application.

• Food Science of Animal Resources
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• v.33 no.1
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• pp.75-82
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• 2013

This study aimed to isolate lactic acid bacteria (LAB) from Kimchi and to identify suitable probiotic strain for application in fermented dairy product as a commercial starter culture. A total of 106 (LAB) strains were isolated from Kimchi collected from different regions in Korea and their phenotypic characteristics were assayed. Four isolates from MRS agar plates were selected and designated as DKL109, DKL119, DKL121 and DKL128. They were identified first by API 50 CHL kit and then 16S rRNA gene sequencing. DKL121 and DKL128 were identified as Lactobacillus paracasei and Lactobacillus casei, respectively. Other two isolates (DKL109 and DKL119) were identified as Lactobacillus plantarum. To estimate their applicability in dairy products, the characteristics including acid and bile tolerance, cold shock induced cryotolerance and enzymatic activities were determined. There was wide variation in ability of strains to acid tolerance, but no significant differences in bile tolerance, cold shock induced cryotolerance within selected strains. DKL119 and DKL121 showed the highest resistance to acid and bile and the highest ${\beta}$-galactosidase activity, respectively. When these two strains were used for yogurt preparation as a single starter culture, their viable cell counts reached to $1.0{\times}10^9CFU/mL$. Lactobacillus plantarum DKL119 showed faster acid development than commercial starter culture. Also storage trials at $10^{\circ}C$ showed that the viability of these strains was retained over 15 d. With these results, it was indicated that probiotics isolated from Kimchi can be used in yogurt manufacturing as a starter culture.