• The Korean Journal of Food And Nutrition
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• v.4 no.1
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• pp.1-8
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• 1991

This study was attempted to establish the basic data for effective utilization of the dried radish and sweet potato. The rehydration characteristic was carried out from these dried root vegetables in various conditions. The following results were obtained. The rehydration value was increased in glycine solution, whereas It decreased in lactic acid solution. Also the vacuum freezing was higher than that in hot air drying, and it was higher the slow freezing than in the quick freezing. The rehydration rate and the rehydration surface area curve were composed of three stages, and these stages were corresponded to each other. At the range of initial immersion to 2min., the largest rehydration rate was showed. The activation energy obtained from the Arrhenius plot of the rehydration rate constant(K) were 3. Bx103ca11g mol and 3.7$\times$103cal/g mol for dried radish and sweet potato, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.10
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• pp.796-804
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• 2013

The "Potato Gun," a simple heat engine, is fabricated, tested and analyzed as a part of engineering education program of combustion and propulsion classes. Combustor pressure is predicted by the chemical equilibrium analysis of a constant volume combustor. Then, the internal ballistics, the conversion of thermal energy into the mechanical energy of a projectile, is predicted though the expansion process. The trajectory of a projectile is estimated by considering the aerodynamic effect around the spherical projectile. The energy conversion efficiency and the equivalence ratio of the fuel-air mixture could be estimated by the comparison of the experimental results and the theoretical prediction. The present work would be an example of attracting the interest of students for the application of the engineering principles at undergraduate level by recycling the waste materials.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.4
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• pp.497-503
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• 2004

The effect of adding carbohydrate-rich feedstuffs to sweet potato leaves (SPL) on silage quality was studied using a total of 180 laboratory silos. Silage quality was assessed by changes of pH, dry matter (DM), crude protein (CP) and ammonia nitrogen ($NH_{3}$-N). Pre-wilted SPL was mixed with cassava root meal (CRM), sweet potato root meal (SPM) or sugar cane molasses (Mo) at levels of 0, 30, 60 and 90 g $kg^{-1}$ (air-dry weight of additives to pre-wilted weight of SPL). Samples for assessing silage quality were collected after mixing the SPL with the additive and thereafter at 7, 14, 28 and 56 days of ensiling. There was a marked decrease in pH after 7 days and the pH remained low and stable until day 56. Addition of 60 and 90 g $kg^{-1}$ resulted in a lower pH (p<0.05) than the other treatments. The DM content of the silage increased (p<0.05) with increasing levels of additive, while there were no differences in DM with time of ensiling. The CP content of the silage decreased (p<0.05) with increasing levels of additive. The CP content did not change up to 28 days, but was lower (p<0.05) after 56 days in all treatments. The $NH_{3}$-N levels were increasing (p<0.05) with time of ensiling, and were lower (p<0.05) with additive levels of 60 g $kg^{-1}$ or higher. Also, the additive source affected the $NH_{3}$-N values, with the lowest values found for Mo. Castrated male pigs (Large White$\times$Mongcai) were used in 4$\times$4 Latin square design to study the total tract digestibility and nitrogen (N) utilisation of diets with inclusion of ensiled SPL. The diets were based on cassava root meal with inclusion of protein from either fish meal (C) or SPL ensiled with CRM (D1), SPL ensiled with SPM (D2) and SPL ensiled with Mo (D3). The digestibility of DM, organic matter (OM) and CP were higher (p<0.05), and the digestibility of crude fibre (CF) was lower (p<0.05), in diet C than in diets D1, D2 and D3. However, there were no differences (p>0.05) in digestibility of dietary components between diets D1, D2 and D3. Also, the excretion of N in faeces was higher (p<0.05) and the N retention was lower (p<0.05) in diets D1, D2 and D3 than in diet C. It can be concluded from the present experiments, that a good quality silage can be produced from pre-wilted SPL by addition of 60 g $kg^{-1}$ of either CRM, SPM or Mo. Diets with inclusion of 450 g ensiled SPL $kg^{-1}$ DM showed a high digestibility of dietary components and thus ensiled SPL should be considered as a potential feed resource for growing pigs.

• Korean Journal of Food Science and Technology
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• v.7 no.4
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• pp.187-193
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• 1975

A supplemental effect of Undaria Pinnatifida extract on the composite flour prepared from a blend of wheat, barley, sweet potato, potato, and defatted soybean flours was studied in terms of binding properties, cooking test, and sensory analysis. Dry noodle of the composite flour was made by the conventional method and air dried. Instant noodle was prepared in a hot vegetable oil bath after the noodle was made. The standard was made of wheat flour only. 1. The noodle prepared with composite flour (wheat flour : barley flour, 5 : 5) and Undaria Pinnatifida extract (1 or 2%) showed same results of cooking and sensory tests as well as properties of texture as the standard. 2. The mixture of wheat, barley and defatted soybean flour (10%) had a less efficient binding capacity with Undaria Pinnatifida extract. The binding effect was, however, significantly improved with the wheat and barley flour mixture with either sweet potato or potato flour. 3. The instant noodle prepared with the composite flour (either barley, or sweet potato, or potato was mixed with wheat flour up to 70% separately) and hydroxypropyl methyl cellulose (1% as final) showed the higher oil absorption and the sensory results were the same as the standard. Nevertheless, the binding properties and cooking quality were less efficient.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.24-31
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• 2013

This study was conducted to determine the characteristics of quality and yield in potatoes grown at paddy field before rice transplantation during the spring season. Three potato cultivars ('Jowon', 'Haryeong', and 'Goun') were grown in Gangneung (asl 5 m) and Seocheon (asl 20 m). In both locations, weather condition belonged to the fourth zone (spring cropping) in potato production location's distribution of Korea. Daily mean soil temperature in both the locations was $0.2-0.6^{\circ}C$ lower than air temperature, while soil moisture was adequate level to potato growth in spite of spring drought. TR ratio was not affected by location, but by cultivar. Specific gravity, starch content, dry matter rate, and yield were significantly influenced by location and by cultivar. There was no difference in total tuber number by location, however there was a large gap in marketable tuber yield according to locations and cultivars. There were high negative relationships between yield and main qualities such as dry matter rate and starch content, while high positive correlation was observed between main qualities. It was possible to produce potato before rice transplanting at drained paddy fields located in representative two locations of potato spring cropping and their characteristics in growth and quality were similar to those generally well known in upland cultivation. Paddy field was thought to be more favorable than upland in terms of available soil moisture supply against spring drought. Further research, however, was needed to increase soil temperature and also preliminary review on proper cultivar according to location seemed to be needed for high yield.

• Journal of Multimedia Information System
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• v.7 no.2
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• pp.189-196
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• 2020

We have developed a device for recording biological data by inserting three electrodes and a needle with an angular velocity sensor into the moth for the purpose of measuring the electromyogram of the flapping and the corresponding lift force. With this measurement, it is possible to evaluate the moth-physiological function of moths, and the amount of pesticides that insects are exposed to (currently LD50-based standards), especially the amount of chronic low-concentration exposure, can be reduced the dose. We measured and recorded 2-channel electromyography (EMG) and angular velocity corresponding to pitch angle (pitch-like angle) associated with wing flapping for 100 sweet potato hawkmoths (50 females and 50 males) with the animals suspended and constrained in air. Overall, the angular velocity and amplitude of EMG signals demonstrated high correlation, with a correlation coefficient of R = 0.792. In contrast, the results of analysis performed on the peak-to-peak (PP) EMG intervals, which correspond to the RR intervals of ECG signals, indicated a correlation between ΔF fluctuation and angular velocity of R = 0.379. Thus, the accuracy of the regression curve was relatively poor. Using a DC amplification circuit without capacitive coupling as the EMG amplification circuit, we confirmed that the baseline changes at the gear change point of wing flapping. The following formula gives the lift provided by the wing: angular velocity × thoracic weight - air resistance - (eddy resistance due to turbulence). In future studies, we plan to attach a micro radio transmitter to the moths to gather data on potential energy, kinetic energy, and displacement during free flight for analysis. Such physiological functional evaluations of moths may alleviate damage to insect health due to repeated exposure to multiple agrochemicals and may lead to significant changes in the toxicity standards, which are currently based on LD50 values.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.165-171
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• 2023

Potato dry rot is one of the potato storage diseases caused by Fusarium species and is a representative pathological disorder that induced post-harvest loss during storage. Chlorpropham treatment for sprouting inhibition is mainly used for room temperature storage of potatoes for processing. In this study, the inhibitory effect of chlorpropham on Fusarium-induced dry rot of potato 'Dano'. To investigate the mycelial growth rate of the dry rot fungus (Fusarium solani Appel & Wollenw), mycelial growth was investigated in a chlorpropham (5.0, 50.4, 503.8, and 5,038 ppm) and prochloraz (0.1, 1.0, 10.0, and 100.0 ppm) medium containing F. oxysporum mycelia. Mycelia were more inhibited as the concentration of chlorpropham and prochloraz increased during incubation at 20℃, and the inhibition rate was 98.2% and 100% when treated with 503.8 ppm of chlorpropham and 10ppm of prochloraz in 14 days, respectively. Potato Dano tubers inoculated with F. oxysporum were dipped in chlorpropham (5.0, 50.4, and 503.8 ppm) and prochloraz (100 ppm) to investigate the effect of preventing dry rot during cold storage at 20℃ and 4℃ in vivo. The disease diameter of potatoes stored at room temperature (about 20℃) was reduced to 13.0 mm in the prochloraz 100 ppm teatment, and 10.7 mm in the chlorpropham 50.4 ppm treatment compared to 13.7 mm in the control tuber at 70 days of storage. The disease progression in all treatments including control was similar with no statistically significant difference at 4℃ air temperature. From the results of this study, it is considered that treatment with 50.4 ppm of chlorpropham after harvest will be useful for suppressing dry rot of stored potatoes.

• Journal of the Korean Ceramic Society
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• v.44 no.2 s.297
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• pp.79-83
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• 2007

To fabricate a thick, porous yttria-stabilized zirconia without cracking and warping, a method for the simultaneous control of the porosity and shrinkage was designed. As a pore former, a potato starch was used. For the control of shrinkage the oxidation of Al metal particles was used. For the sintering of the above powder mixtures, a partial sintering technique was used at $1300^{\circ}C$ for 10 min in air. Upon adding the additives, high open porosity above 53% and a low shrinkage level were obtained. As a result cracking and warping of the sintered body were deterred. This outcome most likely resulted from the compensation of sintering shrinkage due to the volume expansion caused by oxidation of the Al metal particles during heat-treatment.

• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.325-336
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• 2023

This study used leaves and stems of 'Tongchaeru', one of the sweet potato varieties, to investigate broiler productivity, meat quality, blood properties, growth hormones, and immune factor levels according to drying method and amount added to feed. For this experiment, a total of 720 1-day-old male Ross 308 broilers were used. Treatments were assigned with 3 replicates per treatment and 20 birds were assigned to each replicate. The treatment group was designed into 12 treatments according to the type of natural product (leaves (L), stems (S)), drying type (natural (N), hot air (H), freeze (F)) and amount added (0.1%, 0.3%). The test was conducted for a total of 5 weeks. In this study, there was no significant difference in productivity depending on the type and amount of additives added (P>0.05). The FS 0.3% group showed high pH and WHC levels, and the shear force was lowest at HL 0.1% group (P<0.05). Blood cell and serum biochemical components were similar in all treatments, and growth hormone IGF-1 was highest in FS 0.1% group (P<0.05). There was no significant difference in IFN-γ, but the highest level of IL-6 was seen in the HS 0.1% group (P<0.05). In conclusion, the meat quality and the level of growth hormone and immune factors in the body were different depending on the type and amount of dried leaves and stems of sweet potato 'Tongchaeru', further study is needed to compare the selected additives and amounts added with those without additions.

• Food Science and Preservation
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• v.12 no.6
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• pp.552-557
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• 2005

Effect of pre- and post-mild heat treatment on quality of fresh-cut potatoes was investigated with the focus on surface color, firmness, phenolics, vitamin C and sensory characteristics. As the pre-heat treatment before cutting of potatoes, dried hot air (DH) and hot water (WH) treatment were conducted at $45^{\circ}C$ for 60 min, respectively. As a post-heat (CH) treatments, potato cubes were dipped into water of $55^{\circ}C$ for 45 seconds after cutting. The potato cubes were packed in 15 cm x 20 cm LDPE pouches $30^{\mu}m$ thick and then stored at $5{\pm}1^{\circ}C$. The respiration rate of fresh-cut potatoes was decreased by mild heat treatment Especially, the rate of cubes treated with DH was decreased by $20\%$ compared to that of the non-heat treated. L value of cubes treated with DH showed higher value than that of others. Firmness and free phenolics had no significant difference between the treatments. The fresh-cut potatoes prepared with non-heat treatment showed higher vitamin C content than that of the heat treated. In sensory visual color, CH treated cubes marked the best quality. Conclusively, mild heat treatment, especially CH treatment, showed positive effect on browning inhibition and quality enhancement of fresh-cut potatoes.