• Journal of Korean Society of Forest Science
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• v.62 no.1
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• pp.82-86
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• 1983

Cone and seed development after self-pollination in 14-year-old Pinus rigida Mill. was investigated in an $F_1$-hybrid seed orchard that consists of Pinus rigida Mill. and Pinus taeda L. in alternative rows. On an average, 83.8% of the self-pollinated receptive female strobili developed into cones. This value appears to be normal compared to cone development after open-pollination in other pine species such as in Pinus sylvestris L. However, there was a great variation in filled seed development after self-pollination among the investigated individual trees (Table 1-1). The 34.5%, a ratio of filled seeds after self-pollination was significantly lower than 91.7%, that by the open-pollination. Some of the investigated trees developed 70.0%-83.5% of filled seeds after self-pollination. Thus, those are not desirable as trees for seed parent in establishing $F_1$-hybrid seed orchards in future. A further study on the rate of filled seed development by various pollination systems consisting of self-pollination, self-and cross-pollination with intraspecific, mixed (tree's own and foreign pollens) pollens and cross-pollination with interspecific, mixed pollens of the two parental tree species is necessary to determine the quality of seed parent trees in establishing $F_1$-hybrid seed orchards.

• Korean journal of food and cookery science
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• v.29 no.2
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• pp.129-135
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• 2013

The objective of this research was to investigate physicochemical properties of waxy sorghum flours by different milling methods (pin mill and ultra fine mill). Four different sorghum flours were used for the experiments ; PWS (pin milled whole sorghum flour), PS (pin milled sorghum flour without bran), UFWS (ultra fine milled whole sorghum flour), UFS (ultra fine milled sorghum flour without bran). The contents of crude ash and total dietary fiber were the highest in PWS. Amylose content of pin milled sorghum flour was higher than that of ultra fine milled flour. The mean particle size of pin milled flours was six times lager than ultra fine milled flours. The L values of UFS and UFWS were higher than those of PS and PWS, whereas a and b values were higher in PWS. The water binding capacity was highest in UFWS, and solubility was higher in PS and UFS. Swelling power of flours was highest in UFS. The damaged starch content was higher in PS and UFS, which means damaged starch of sorghum flours significantly affected by polishing than milling method. The pasting properties were higher in the pin milled flours. Initial pasting temperature of pin milled flour was ranging from 70.5 to $73.1^{\circ}C$, which are higher than ultra fine milled flour ($68.6^{\circ}C$). The contents of total polyphenol were higher in PWS and UFWS than those of PS and UFS, there was no difference between the two milling methods. The results of this study indicate that physicochemical properties of sorghum flour were affected by milling methods as well as bran.

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.693-697
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• 2005

We researched in the optimization of unit process and the stabilization of discharged water quality through the treatment of the occurrence of wastewater classified by place of production which has high COD load and non degradable COD load in paper industry. As the result, using polymer, inorganic flocculants and alum at the same time is effective to advance the COD value through the colloid material removal with SS in the first treatment process. Moreover, it is determined to keep optimum of $FeCl_2/H_2O_2$ in the concentration of 1000 ppm in the ratio of 1/1. Because It is confirmed that to input excess chemicals using Fenton oxidation method gives adverse effect to water quality.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.3
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• pp.261-269
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• 2009

Micro end-milling process is applied to fabricate precision mechanical parts cost-effectively. It is a complex and time-consuming job to select optimal process conditions with high productivity and quality. To improve the productivity and quality of precision mechanical parts, micro end-mill wear and cutting force characteristics should be studied carefully. In this paper, high speed machining experiments are studied to construct the optimum process design as well as the mathematical modeling of tool wear and cutting force related to cutting parameters in micro ball end-milling processes. Cutting force and wear characteristics under various cutting conditions are investigated through the condition monitoring system and the design of experiment. In order to construct the cutting database, mathematical models for the flank wear and cutting force gradient are derived from the response surface method. Optimal milling conditions are extracted from the developed experimental models.

• Journal of the Korean Wood Science and Technology
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• v.37 no.5
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• pp.421-425
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• 2009

This research investigates the effect of copper retention on copper leaching in wood treated with copper-based preservatives. Radiata pine (Pinus radiata D. Don) sapwood samples were ground in a Wiley mill equipped with a 20-mesh screen. The ground wood was vacuum-treated with various concentrations of alkaline copper quat (ACQ), bis-(N-cyclohexyl-diazeniumdioxy)-copper (CB-HDO), and copper azole (CUAZ). The treated samples were conditioned at $70^{\circ}C$ and 100% RH for 72 hours. The samples were leached by using the distilled water for four weeks, and the copper contents in each sample were measured by X-ray spectroscopy. As expected, the copper leaching was increased with increasing of copper retention. The copper leaching from the ACQ and CB-HDO treated samples were gradually decreased with increasing copper retention: however, the copper losses from the CUAZ treated samples appeared to be proportionally increased with the increase in copper retention in all retention levels tested. The results indicate that at the conditions of the same copper retention ACQ and CB-HDO treated wood have a better leaching resistance compared to CUAZ treated wood.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.53-53
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• 2008

Piezoelectric transformers have been widely used such as DC-DC convertor, invertor, Ballast, etc. Because, the y have some merits compared with electro-magnetic transformers such as step-up ratio, high efficiency, small size and lg hit weight, etc. Piezoelectric transformer require high electromechanical coupling factor kp in order to induce a large out put power in proportional to applied electric field. And also, high mechanical quality factor Qm is required to prevent mechanical loss and heat generation. In general, PZT system ceramics should be sintered at high temperatures between 1200 and $1300^{\circ}C$ in order to obtain complete densification. Accordingly, environmental pollution due to its PbO evaporation. Hence, to reduce its sintering temperature, various kinds of material processing methods such as hot pressing, high energy mill, liquid phase sintering, and using ultra fine powder have been performed. Among these methods, liquid phase sintering is basically an effective method for aiding densification at low temperature. In this study, In order to comparis on low temperature sintering and solid state sintering piezoelectric transformers, rosen type transformers were fabricated u sing two PZT ceramics compositions and their electrical properties were investigated.

• Journal of Mechanical Science and Technology
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• v.20 no.9
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• pp.1410-1417
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• 2006

The metal processing system usually consists of various components such like motors, work rolls, backup rolls, idle rolls, sensors, etc. Even a simple fault in a single component in the system may cause a serious damage on the final product. It is therefore necessary to diagnose the faults of the components to detect and prevent system failure. Especially, the defects in a work roll are critical to the quality of strip. It is especially difficult to detect faults of a roll by using the existing frequency analysis method if the speed of the roll is changing. In this study, a new diagnosis method for roll eccentricity under the roll speed changes was developed. The new method was induced from analyzing the rolling mechanism by using rolling force models, radius-speed relationship, and measured rolling force, etc. Simulation results by using the field data show that the proposed method is very useful.

• Journal of Industrial Technology
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• v.22 no.A
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• pp.119-125
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• 2002

In Kwangjin industrial company, mill is operating for the foundry sand production at the rate of 25t/hr from quartzite. Foundry sands fall into four distinct categories: silica sand, lake sand, bank sand, and natural molding sand. Silica sand is a general term used to describe crushed, washed, graded, dried, and cooled clay-free sands. This study was conducted for the investigation of the foundry sand productivity and the life span of the hammer according to the material quality. The life time of hammer from several manufacturer were compared in order to find out the grinding efficiency of the various hammer material. In the result of tests, the life time of high-Mn hammer was 10.5 hours while that of high-Cr was 19.5 hours. The life time in case of typical worn shape hammers was about 12 hours and the average time of a blowhole hammer was about 6.5 hours.

• Transactions of Materials Processing
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• v.8 no.1
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• pp.78-91
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• 1999

The endless hot rolling has been focused as an innovative process technology for increasing the productivity drastically and reducing the imperfection of quality in hot rolled steel strip. To realize it in actual mill, a lots of new facilities such as bar coiler, movable LASER welder and high speed strip shear should be equipped. And also it is necessary to develop the control technique for changing the roll gap and rolling speed during rolling, which is named as Flying Gap and Speed Change control technology. To prevent a strip rupture caused by excessive tension, it is very important to minimize fluctuations in strip thickness and intension during FGSC control. In this paper, the mathematical model for FGSC control algorithm was suggested and dynamic simulation is performed to accertain the effect of suggested control method on fluctuations in strip thickness and tension. For endless hot rolling simulation, a lots of FGSC control situations, for instance - strip thickness change from strip to strip - strip width change from strip to strip - carbon content change from strip to strip are considered.

• Korean Journal of Food Science and Technology
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• v.18 no.5
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• pp.335-338
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• 1986

A simple spectrophotometric technique using sequential extraction of pigments was attempted to perform color evaluation of raw 'Taimuri' tomato (Lycopersicon esculentum Mill.) fruits. The difference between summed absorbance of 80% acetone and chloroform extract at 480 nm and 660 nm reflected the maturity of rawtomato fruits. The measurement system presented was regarded as a simple and reliable method for objective color evaluation of tomato fruits. It seems possible to predict the degree of puffiness by weight per volume w/v ratio of tomato fruits during various stages of maturity.