• 한국산림과학회지
• /
• 제62권1호
• /
• pp.82-86
• /
• 1983

리기테다소나무 일대잡종(一代雜種) 종자(種子) 생산용(生産用) 잡종채종원(雜種採種園)에서 테다소나무와 개화기(開花期)가 일치(一致)될 가능성이 큰 리기다소나무의 암꽃 조기개화(早期開花) 개체(個體)들을 예비조사에 의해 선발한 후, 이들에 대해 자배(自配)를 실시하여 다음과 같은 결과(結果)를 얻었다. 자배후(自配後) 구과(毬果)의 발달(發達)은 개체에 따라 상당한 차이를 보여 주었으나 평균(平均) 83.8%의 착과율(着果率)을 나타내어 자배후(自配後)에로 대부분의 구과(毬果)가 정상적으로 발달하는 것으로 생각된다. 리기다소나무의 경우 자가수정(自家受精)에 의한 충실종자(充實種子) 발달비율(發達比率)은 평균 34.5%로서 풍매수분(風媒受粉)에 의한 충실종자 발달비율 91.7%에 비하여 훨씬 저조하였으나 구주소나무에 비하여 자가수정에 의한 충실종자 발달비율이 비교적 높은 편이었다. 특히 몇몇 개체들은 그 비율이 70.0~83.5%에 이르러 $F_1$ 잡종채종원(雜種採種園) 조성용(造成用) 모수(母樹)로서의 그 가치(價値)가 의문시 된다. 새로운 일대잡종채종원(一代雜種採種園)을 조성할 때에는 선발된 종자모수들에 대하여 예비적인 자배시험(自配試驗)을 통하여 종자모수(種子母樹)로서의 적합성(適合性) 여부를 검정할 필요성이 충분히 있다고 생각되며 나아가서는 양친수종(兩親樹種)의 종간(種間) 혼합화분교배(混合花粉交配)에 의한 잡종종자(雜種種子) 생산능률(生産能率)도 검토해야 할 것으로 생각된다.

• 한국식품조리과학회지
• /
• 제29권2호
• /
• pp.129-135
• /
• 2013

분쇄방법(핀밀, 초미분쇄)을 달리하여 제분한 찰수수가루의 물리화학적 특성을 조사하였다. 조단백질 함량은 PS와 UFS에서 높았고, 조지방 함량은 핀밀분쇄보다 초미분쇄에서 더 높게 나타났다. 조회분과 총 식이섬유소 함량은 도정하지 않고 핀밀분쇄한 PWS에서 가장 높았다. 겉보기 아밀로오스 함량은 핀밀분쇄한 수수가루가 초미분쇄한 수수가루보다 높았으며 껍질이 없는 경우(PS, UFS) 아밀로오스 함량이 더 낮게 나타났다. 수수가루의 평균입도크기는 도정하지 않은 수수가루에서 컸으며 핀밀분쇄한 것이 초미분쇄보다 평균입도가 큰 것으로 나타났다. 수수가루의 색도는 초미분쇄 수수가루가 핀밀수수가루보다 밝았으며 UFS의 L값이 가장 높았고, 도정한 수수가루(PS, UFS)가 통곡수수(PWS, UFWS)보다 명도가 높았다. 수분결합력은 초미분쇄 시료 UFWS에서 가장 높았으며 핀밀분쇄 PWS보다 높았다. 용해도와 팽윤력은 초미분쇄한 시료가 핀밀분쇄 시료에 비해 모두 높게 나타났으며 도정한 수수가루에서 높게 나타났다. 수수가루의 손상전분 함량은 핀밀분쇄하여 도정한 경우 손상도가 컸다. 수수가루의 호화점도 특성에서 최고점도와 최종점도 PS와 PWS에서 높았고 UFS는 가장 낮은 점도를 나타내었다. 노화도를 나타내는 setback 점도 또한 PS와 PWS에서 높아 초미분쇄보다 노화도가 높게 나타났다. 핀밀분쇄한 통곡 수수가루(PWS)가 전체적으로 높은 호화점도곡선을 보였다. 총 페놀 함량은 핀밀분쇄 수수가루가 초미분쇄 수수가루보다 높았으며 통곡 수수에서 높게 나타났다. 이러한 결과들로 보아 수수는 도정 여부와 분쇄 방법에 따라 가루의 물리화학적 특성이 달라지므로 수수가루를 이용한 제품 개발 시 각 제품의 특성에 따른 적절한 제분방법이 필요하다고 할 수 있다.

• 공업화학
• /
• 제16권5호
• /
• pp.693-697
• /
• 2005

제지산업에서 COD 부하 및 난분해성 COD 부하가 높은 생산지종별 발생폐수의 처리방안을 통하여 단위공정의 최적화와 방류수의 수질 안정화에 대해 연구하였다. 그 결과 1차 처리 공정에서는 SS와 더불어 colloid성 물질제거를 통한 COD 제거효율을 향상시키기 위해서 음이온 응집제 및 Alum의 병행사용이 효과적인 것으로 분석되었다. 또한 Fenton 산화법의 병행사용으로 인한 약품의 과량투입은 수질상태에 악영향을 주는 것으로 확인되었기 때문에 최적량인 $FeCl_2$와 $H_2O_2$의 비가 1:1인 농도비 1000 ppm 일 때 COD 제거율이 가장 높다고 판단된다.

• 한국생산제조학회지
• /
• 제18권3호
• /
• pp.261-269
• /
• 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
• /
• 제37권5호
• /
• pp.421-425
• /
• 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.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.53-53
• /
• 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
• /
• 제20권9호
• /
• pp.1410-1417
• /
• 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.

• 산업기술연구
• /
• 제22권A호
• /
• pp.119-125
• /
• 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.

• 소성∙가공
• /
• 제8권1호
• /
• pp.78-91
• /
• 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.

• 한국식품과학회지
• /
• 제18권5호
• /
• pp.335-338
• /
• 1986

토마토의 색도를 측정하기 위해 색소의 sequential extraction을 이용한 spectrophotometric technique을 시도하였다. 파장 480nm 와 660nm에서 각기 80% acetone과 chloroform으로 추출된 용액의 흡광도를 합한 다음 두 파장에서의 총 흡광도 차이를 구한 결과 토마토의 숙성(ripening) 정도가 잘 반영되었다. 이러한 측정방법은 토마토 색소의 객관적 측정을 위한 간단하고 신뢰성 있는 방법으로 간주된다.