• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.732-736
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• 2016

Air conditioning part designs are moving towards higher efficiency and productivity. The expansion device is one of the core parts of an air conditioning system and controls the refrigerant quantity, evaporation load, compression capacity, and condensation capacity. In this study, an electronic expansion valve for two working fluids ($CO_2$ and R134a) was developed for air conditioning systems in vehicles. The valve uses an eccentric cam driving structure instead of a lead screw to decrease manufacturing costs and increase productivity. The pressure resistance and flow rate performance was evaluated using numerical analysis. At maximum operation conditions and burst pressure conditions with $CO_2$, the maximum stresses on the valve model were about 98 MPa and 223 MPa, respectively. The maximum flow rates of $CO_2$ and R134a with different orifice openings were about 550 kg/h and 386 kg/h, respectively. The performance with R134a was verified by experiments.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.239-248
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• 2019

This research presents an improvement of the physical and mechanical properties of composite board (com-ply) made of Oriented Strand Board (OSB) coated with wood veneer of Pine (Pinus merkusii), Avocado (Persea Americana) and Mahogany (Swietenia mahogany). 1.5 mm thick veneers of those three wood types were adhered to the surface of OSB using two adhesive types: epoxy and isocyanate. The adhesive with the glue spread of $250g\;m^{-2}$ applied using single glue line was spread and then cold pressed with the pressure of $15kg\;cm^{-2}$ for 3 hours. The research result showed an improving dimension stability of com-ply, but not found on all parameters of physical property test. The moisture content seemed to be influenced by the com-ply type, yet not related to its thickness swelling, water absorption and linear expansion. The exception took place in the parallel linear expansion when immersed for 2 hours. The highest to the lowest increases of MOE and MOR were consecutively found on OSB coated with wood veneer of Pine, Mahogany and Avocado. However, the increases were statistically insignificant. The highest increasing screw hold power was found at the com-ply type AE (avocado veneer and epoxy adhesive) that was by 28%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1170-1176
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• 2016

The aim of this study was to investigate the effects of screw speed, moisture content, and die temperature on the physical properties of extruded soy protein isolate. Extrusion conditions were moisture content (20 and 25%) and die temperature (120, 130, and $140^{\circ}C$) at a fixed screw speed of 250 rpm. The other extrusion conditions for screw speed (150, 200, 250, 300, and 330 rpm) were a fixed moisture content and die temperature of 30% and $140^{\circ}C$, respectively. Specific mechanical energy input decreased as die temperature increased from 120 to $140^{\circ}C$, whereas specific mechanical energy input increased as screw speed increased from 150 to 330 rpm. Expansion ratio and specific length increased as die temperature increased. Breaking strength decreased as die temperature increased and moisture content decreased. A lower moisture content resulted in a greater color difference. Integrity index increased as die temperature increased from 120 to $140^{\circ}C$ and moisture content decreased from 25 to 20%. Nitrogen solubility index decreased as screw speed increased from 150 to 330 rpm. Nitrogen solubility index was lowest at $2.83{\pm}0.51%$ as screw speed decreased to 150 rpm. In conclusion, moisture content was a more important factor than die temperature for texturization of soy protein isolate.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.673-677
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• 2003

Congenital aglossia is a very rare condition. The oral manifestations of an aglossia include micrognathia, high arched or cleft palate, defects of the lower lip, an absence of lateral incisors and a mandibular growth deficiency. Although the etiology of congenital aglossia is unclear, both genetic and teratogenic mechanisms have been proposed. Treatment of aglossia patients depends on the nature and severity of the condition which includes surgical rehabilitation of the tongue tip to some extent, orthopedic expansion of the mandible to guide mandibular growth, and mandibular expansion by a distraction osteogenesis. In the present case, a 6 year old female aglossia patient with situs inversus was treated. A bonded hyrax screw was used to increase her mandibular primary intercanine width and intermolar width. A second phase orthodontic and surgical treatment will be possible after some retention phase.

• The korean journal of orthodontics
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• v.11 no.2
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• pp.135-142
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• 1981

This study was performed to observe the gross reactions of surrounding maxillary sutures to the widening of midpalatal suture in the dog. Three healthy dog were chosen for the experiment. One animal was used as control, and two were used as experimental animals. Midpalatal suture was expanded total 7mm with screw for 10 days. The following results were obtained : 1. Midpalatal suture was expanded with the most width, in which anterior was be more expanded than the posterior, and shape was wedge form. 2. Interincisive suture was definitely expanded. 3. Internasal suture and interfrontal suture were slightly expanded. 4. Expansion of frontomaxillary suture, frontoparietal suture, frontonasal suture, zygomatico temporal suture, zygomatico frontal suture, zygomatico maxillary suture, occipito mastoid suture, occipito parietal suture, naso incisive suture, naso maxillary suture, and incisive maxillary suture were not observed.

• Journal of the East Asian Society of Dietary Life
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• v.2 no.2
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• pp.277-282
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• 1992

This study was designedto investigate changes in phsicochemical properties of rice extrudate with added glycerin fatty acid ester extruded by single screw extruder. According to emulsifier content, expansion ratio and water solubility index were represented minimum in rice extrudate with added 2.0% and 2.5% glycerin fatty acid ester. Extrudate with added 1.5% emulsifier revealed lowest break strength and bulk density, so got a tender and light texture. Meanwhile water absorption index was showed maximum at 1.5% emulsifier content. As emulsifier content increased, lightness raised. By the microstructure obsorved with image analyzer, addition of emulsifier had decreased area and fractarea of air cells of cross section of extrudates. On the results of this research, quality of extrudate with added 1.5% glycerin fatty acid ester was considered very well than 100% rice extrudate, because of tender and light texture, highest water absorption indexand fine structure with higher lightness.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.3
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• pp.379-383
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• 2007

The effects of phenolic acids on the physical properties of wheat flour extrudate were investigated. Ferulic acid, fumaric acid, and p-coumaric acid were mixed with hard wheat flour, respectively, and extruded under a twin screw extruder. We found that by adding the phenolic acids, longitudinal expansion at the die increased, textural hardness decreased, and the water absorption capacity of the extrudate decreased. The results showed that the addition of phenolic acids produced a softer textured, more longitudinally puffed and hydrophobic extrudate compared to the control extrudate. Moreover, the addition of phenolic acids did not significantly affect the color of the extrudate: oxidative browning of the phenolic acids was not observed, due to inactivation of the browning enzymes under the hot temperature and reduced oxygen conditions of the extrusion process.

• Korean Journal of Food Science and Technology
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• v.22 no.4
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• pp.451-455
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• 1990

The extrusion characteristics of pork rind mixed with corn flour were investigated. The blends of pork rind to corn flour in the ratio of 1 : 2, 1 : 1, 2 : 1 and 3 : 1(w/w) were made and each blend was dried up to 5, 10 and 15% moisture content. The blends were extruded by single screw extruder. The extrusion characteristics of each extrudate were as follow. The highest value of expansion ration was attained by mixing pork rind and corn flour in the ratio of 1 : 1, containing 5% moisture content. As the rind content to the corn flour mixture was increased, the bulk density, water absorption index, breaking stregth and redness, of the extradate increased, but the lightness and yellowness decreased. It was concluded that a high quality snack food could by produced by extrusion-cooking the mixture of pork rind and corn flour.

• Journal of the Korean Wood Science and Technology
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• v.18 no.2
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• pp.67-78
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• 1990

This study was performed to determine the characteristics of physical and mechanical properties of domestic wood based materials; plywood, particleboard, medium density fiberboard. Main items of tested properties were panel size, moisture content, water absorption, linear expansion and thickness swelling, glue bond shear strength, bending properties(stress at proportional limit, modulus of rupture. modulus of elasticity), tensile strength, screw holding strength, and internal bond as neccessary. the results were discussed mainly with Korean Standards. The obtained conclusions are as follows; 1. Length and width of 3mm thin plywood(3-ply) and 12mm thick plywood(7-ply) were satished with KS-standard, but thicknesses of these panels were not- passed tolerance limit except one of eight makers. 2. Length and width of particleboard and medium density fiberboard were greater than the tolerance limit value of KS standard, but the thicknesses of these panels were passed this value. 3. Moisture contents of 12mm thick and 3mm thin plywood were satisfied with KS-standard except one mill made 3mm thin plywood. 4. Moisture absortion of plywood was not passed tolerance limit of KS-standard but particleboard was satisfied with this standard value. 5. Dry and wet shear strengths in glue bond of 3mm thin plywood were not reached to KS-standard, but those of 12mm thick plywood were sufficiently satisfied with KS standrad. 6. Modulus of ruptures, parallel to grain and perpendicular to grain of plywood, and particleboard and medium density fiberboard were satisfied with KS-standard. 7. Tensile strengths, parallel to grain and perpendicular to grain of plywood were satisfied with allowance stress of US product standard PS 1-74. 8. Screw holding strength of particleboard was not reached to KS standard, but internal bond was satisfied with KS standard.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.463-469
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• 1988

The effects of moisture content and particle size of rice flour on the physical properties of the extrudate were examined by using a autogeneous single screw extruder. The moisture contents tested were in the range of 17-28% and the particle sizes were 18-60mesh and 60-120mesh. Samples were taken at different temperatures from the start-up period to the steady state operation. The expansion ratio increased and bulk density decreased as the moisture content and particle size of the flour decreased. The cutting force decreased and the air cell size became uniform as the moisture content and particle size of the flour decreased. As the moisture content increased, the yellowness of the extrudate powder decreased, while the lightness increased, the apparent viscosity increased and the water soluble index decreased. Gelatinization and partial dextrinization were apparent during the extrusion process, and the degree of dextrinization was appeared to be influenced by the levels of moisture content and particle size of rice flour.