• Journal of the Korean Society of Safety
• /
• v.13 no.2
• /
• pp.104-108
• /
• 1998

In order to evaluate the performances of safety valves for low pressure, the popping pressure and flow rate of the natural gas have been investigated. The measured results of the popping pressure show that there is a big scattering depending on the manufacture year of a safety valve. And sample A showed the ideal popping pressure mode compared to other B and C samples. The popping flow rate of the safety valve is proportional to the seat size as the inlet pressure increases. These results may be used as a guideline for a design and diagnosis of the safety valve.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.40 no.2
• /
• pp.167-174
• /
• 1995

This experiment was carried out to investigate the major characters affecting the popping volume of popcorn. Tuygimok 1 (Kp1 ${\times}$ Kp2) and 8 popcorn hybrids' agronomic characters were tested to evaluate a certain extent how much they affect on the popping volume. Moisture con-tent was considered as the most important factor, but failed to evaluate the optimum moisture con-tent level in this experiment moisture range (12.2-14.4%) because popping volume increased as moisture content of kernels increased. The maximum popping volume was obtained at 55-60kg of kernel hardness, 80-90,um of pericarp thickness and 45-50% of S/H (Soft/Hard starch). But the Em/En(Embryo/Endosperm) ratio was negatively associated with the popping volume. Therefore the minimum popping volume was observed at the 10-11 % of Em/En ratio. Moisture content, hardness, pericarp thickness, Em/En and S/H ratio were selected as the appropriate variables for the maxi-mum popping volume using the stepwise forward regression method and the expecting popping volume was estimated by the multiple linear regression formular. The mean popping volume of ninepopcorn hybrids was about 29.2cm3/g.

• Journal of the Korean Wood Science and Technology
• /
• v.40 no.3
• /
• pp.147-155
• /
• 2012

Switchgrass was selected as a promising biomass resource for bioethanol production through popping pretreatment, enzymatic saccharification and fermentation using commercial cellulase and xylanase, and fermenting yeast. The reducing sugar yields of popping pretreated switchgrass after enzymatic saccharification were above 95% and the glucose in thesaccharificaiton solution to ethanol conversion rate after fermentation with $Saccharomyces$ $cerevisiae$ was reached to 89.6%. Chemical compositions after popping pretreatment developed in our laboratory were 40.8% glucose and 20.3% xylose, with much of glucose remaining and only xylose decreased to 4.75%. This means that the hemicelluloses area broke off during popping pretreatment. FE-SEMexamination of substrate particles after popping pretreatment was showed fiber separation, and tearing and presence of numerous micro pores. These changes help explain, enhanced enzymatic penetration resulting in improved hydrolysis of switchgrass particles after popping pretreatment.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.40 no.1
• /
• pp.98-102
• /
• 1995

Popped popcorn generally have a regular popping direction and typical shape. But the reason and mechanism are not clear yet. This experiment was carried out to investigate the shape moulding factor of popped popcorn. Pericarp thickness of tip-cap section of kernels is slightly thicker than that of top section and this fact provides the important information to the reason. Popping starts when the moisture pressure of heated popcorn is increased and reaches at the critical pressure. Therefore, in the same moisture pressure conditions, top sections are bursted first because their pericarp section is thinner than that of tip-cap section. At the very moment tip-cap sections pull down the top sections of peri carp as bi-metal does. So kernels which removed tip-cap section showed the irregular popping shape because they lost the tip-cap pericarp function. How-ever, kernels which removed embryo showed the typical popping shape but their popping volume was small due to emition and shortage of critical moisture pressure. But kernels which removed the whole pericarp and top pericarp were not popped at all because moisture was entirely emitting out of kernels. These results suggest that the shape moulding factor of popped popcorn is the pericarp thickness differences between the top and tip-cap section of kernels.

• Journal of Broadcast Engineering
• /
• v.15 no.6
• /
• pp.715-722
• /
• 2010

As one of applications in augmented realities, this paper presents a bubble popping system utilizing a haptic vibro-tactile mouse. In this system, virtual bubbles randomly float in the 3D space. By using the vibro-tactile mouse grabbed by a user, the bubbles are popped when they are touched by the mouse in the 3D space. Then a bubble popping effect with addition mouse vibration is delivered to the user's hand through the mouse. The proposed system is developed on ARToolkit environment. Therefore, basic components such as a camera and a marker pattern are required. The systems is composed of a vibro-haptic mouse, a webcam, a marker pattern, a graphic bubble object, and graphic mouse. Mouse vibration as well as bubble fade-out effect is delivered. Therefore, the combination of visual and tactile bubble popping effects outperforms the usage of a single effect in the experience of augmented reality.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.11 no.4
• /
• pp.12-18
• /
• 2002

Silicon on insulator(SOI) wafer is used in a variety of microsensor applications in which thermal deformations and other mechanical effects may dominate device Performance. One of major Problems associated with the manufacturing Processes of the microaccelerometer based on the tunneling current concept is thermal deformations and thermal stresses. This paper deals with finite element analysis(FEA) of residual thermal deformations causing popping up, which are induced in micrormaching processes of a microaccelerometer. The reason for this Popping up phenomenon in manufacturing processes of microaccelerometer may be the bending of the whole wafer or it may come from the way the underetching occurs. We want to seek after the real cause of this popping up phenomenon and diminish this by changing manufacturing processes of mic개accelerometer. In microaccelerometer manufacturing process, this paper intend to find thermal deformation change of the temperature distribution by tunnel gap and additional beams. The thermal behaviors analysis intend to use ANSYS V5.5.3.

• Journal of the Korean Society of Tobacco Science
• /
• v.17 no.2
• /
• pp.149-159
• /
• 1995

The freeze drying rate was investigated under various conditions such as pressure and moisture contents in order to establish the optimum condition for expansion of the culled flue cured tobacco lamina. The optimal pressure in the chamber to maintain the heat and mass transfer was about 0.8torr, When the moisture contents of sample was 50-60%, expanding rate was the optimum condition and the rate was 67-76%. As the thickness of the sample layers was increased, drying-rate was decreased conversely and this result seemed to be due to decline of heat and mass transfer coefficients. Differences with the position of its stalk were also observed in drying rate, and low stalk position leaves of 5 and 3 was the fastest. Key words : freeze drying, Popping, expansion tobacco.

• Journal of Korea Game Society
• /
• v.11 no.1
• /
• pp.131-138
• /
• 2011

Recently in terrain rendeing, most researches introduce mipmap-based out-of-core methods for handling large sized DEM data which does not fit in main memory of general computer. However, mipmap-based LOD(level-of-detail) methods occur geometric errors which appear in data simplifying the higher LOD level. These geometric errors cause geometric popping effects where LOD level changes when viewpoint moves. In this paper, we propose vertex cohesion map for reducing geometric error. In preprocessing step, we generate vertex cohesion map, which is a texture that stores the vectors. By these vectors, each vertex will be cohered into the position in which the difference of gradient value is bigger than others. Therefore in terrain rendering, using vertex cohesion map can dramatically reduce the geometry popping effects rather than using mipmap.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.23 no.5
• /
• pp.90-100
• /
• 2019

Hypergolic thrusters have been extensively researched and applied to spacecraft propulsion based on their simplicity and high reliability of ignition. Research on the impingement characteristics of $N_2O_4$/amine has been profoundly carried out since the 1960s in advanced countries, especially the United States. Recently, enhancements to advanced hypergolic thrusters using MON/MMH have been planned by NASA to improve compactness and high performance. In this work, technical studies were investigated on the mixing of hypergolic propellant and its combustion instabilities such as reactive separation flow and popping.

• The Korean Journal of Food And Nutrition
• /
• v.29 no.4
• /
• pp.465-473
• /
• 2016

This study was conducted in order to investigate the antioxidant capabilities and quality characteristics of instant porridge made of foxtail millet (Setaria italica Beauv.) from different varieties with different endosperm characteristics and processing using different methods. The two foxtail millet varieties used in this study were waxy foxtail millet, 'Samdachal', and non-waxy foxtail millet, 'Samdame'. The means of processing food to create instant porridge were dry cereal frying, wet cereal frying, freeze drying after steaming, popping, and no treatment. The WAI (water absorption index) of instant porridge made of waxy foxtail millet was higher than that of non-waxy foxtail millet, and popping created the highest WAI among the treatments tested. Whean we analyzed RVA characteristics of non-waxy foxtail millet instant porridge, peak viscosity and setback values were decreased in all processed foxtail millet instant porridge compared to non-waxy foxtail millet instant porridge. In waxy foxtail instant porridge, the peak and final viscosities of processed treated instant porridge increased. The viscosity just after pouring hot water into the instant porridge was higher in waxy foxtail millet porridge treated by freeze drying after steaming, popping, and wet cereal frying; the viscosity of non-waxy foxtail porridge was increased after popping as compared with the other treatments. The polyphenol contents and antioxidant activities were increased in all processed, treated-instant porridge except for freeze dried porridge after steamingnt. The popping treatment showed the highest polyphenol contents (1.5 fold), and ABTS antioxidant activity (1.2 fold), compared to no treatment. Non-waxy foxtail millet porridge produced by popping earned the highest sensory evaluation scores.