• 한국응용과학기술학회지
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• 제23권4호
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• pp.347-354
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• 2006

Generally, it has been known that positive plate efficiency is the most influential effect on the initial current capacity of lead acid battery. Thus, in this study, we have investigated the curing effect of the positive plate, which is one of the important lead acid battery processes. The curing process of the positive plate is performed either with the separation of each plate with 1mm gap or with no gap of plate. As a result, when there is no interval between each plate, the higher temperature current happened than expected, resulting in the changes in the initial current efficiency of the lead acid battery. The chemical composition and crystal structure of a material coated on the positive plate were identified with XRD and SEM. It was resulted that were only there not a lot of 4BS (tetrabasic-lead sulfate, $4PbO{\cdot}PbSO_4)$ on the plate in case of curing of plates without interval, but a large quantity of $Pb_3O_4$ also formed on the surface. On the other hand, it was observed that 3BS (tribasic-lead sulface, $3PbO{\cdot}PbSO_4{\cdot}H_2O)$ was the main product on the plate in case of typical curing process with some interval. From the initial current capacity test, the positive plate having 3BS was approximately 40% higher in initial current capacity than that having 4BS. It was concluded that 4BS and $Pb_3O_4$ on the plate surface were harmful to the initial current capacity of lead acid battery.

• 대한디지털의료영상학회논문지
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• 제13권4호
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• pp.145-151
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• 2011

The purpose of this study is to know some changes of resolution and image if we remove scattered ray using lead plate when doing lumbar lateral projection. Using 3 DR system(2 FD types, 1 CCD type) equipments and 2 film system equipments, we gain the image whether the phantom of abdomen equivalent sticking resolution chart has lead plate or not, whether we do collimation or not. Also, we use ion chamber, measure radiation exposure rate and change to entrance surface dose from it. we gain that images in the greatest condition of taking in clinic. 5 people in this group decoded resolution with our eyes, measured thickness of images and compared them from each equiments. Resolution has difference to size of collimation in DR FD type. Also there is no difference the original image with the new image which we abbreviated mAs. In DR CCD type, resolution didn't have difference whether lead plate is or not and whether we do collimation or not. In film type, existing or nonexisting of lead plate didn't influence on resolution. Lead plate makes the quality of image higher due to reducing scattered ray, it doesn't influence on resolution.

• 한국응용과학기술학회지
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• 제25권1호
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• pp.41-47
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• 2008

This study was conducted to made a grid alloy (Pb-Ca-Sn-Al) which has a temporary composition ratio in order to improve the efficiency of lead acid batteries. The positive activity material made a 3BS(tri-basic lead sulfate; $3PbO{\cdot}PbSO_4{\cdot}H_2O$) by a low temperature curing and it evaluates the plate efficiency through the life cycle testing. The initial current capacity of low temperature curing plate was excellent but the life cycle was not good (S1). As for the S2 plate, however, the initial current capacity and the life cycle were superior.

• 한국응용과학기술학회지
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• 제31권2호
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• pp.197-202
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• 2014

Positive plate was composed of lead hydroxide via reaction between lead oxide and $H_2O$ and lead sulfate was formed of the reaction of lead hydroxide with sulfuric acid. And its density is $3.8g/cm^3$, $4.0g/cm^3$, $4.2g/cm^3$ and $4.4g/cm^3$ by controlling volume of refined water. Curing of positive plate is done for low ($45^{\circ}C$, 40hr, over 95% of relative humidity) & high ($80^{\circ}C$, 40hr, over 95% of relative humidity) temperature, which created 3BS & 4BS active materials. Experimental result of DOD with 100% life cycle test shows that it was not related to the density of active materials but to the low & high temperature aging of active materials. The test makes us to understand that the crystallization which is made by curing of active materials is a more of a main factor than density of active materials under the deep cycle using circumstances. The active materials which were from the high temperature curing are better for deep cycle performance.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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• pp.177-181
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• 1995

Lead-acid battery is used widely as a power source in the automobile, industrial machines, folk lifts U.P.S etc. But this battery has man\ulcorner disadvantages such as heavy low energy density, environment problem etc. In this paper, we have studied the physicochemical and electrochemical properties of lead-acid battery positive plates with regard to the method of curing. It has been observed that curing conditions strongly influence electrode composition and electrchemical performance.

• 터널과지하공간
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• 제22권1호
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• pp.54-59
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• 2012

노천에서 폭파실험을 통해 납판 발파압계의 변형량을 계측하였다. 홉킨슨 바 시험장치의 가스 건으로 압력 실험하여 구한 보정 그래프에 계측데이터를 적용하여 폭풍압을 산출하였다. 그 결과를 CONWEP, DDESB 등 여러 가지 폭풍압 예측식과 대비하였다. 근거리 폭풍압의 실 계측 값은 폭풍압 예측식의 결과보다 최대압력이 낮게 나타났지만 거리에 따른 압력감쇠는 폭풍압 예측식보다 완만한 것을 확인할 수 있었다. 이는 기존 이론식으로 추정한 초근접 지점의 발파압은 부정확함을 의미한다.

• 한국응용과학기술학회지
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• 제25권4호
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• pp.518-524
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• 2008

In this study, positive plates of lead acid battery of Pb-Ca alloy and Pb-Ca-Sn alloy were fabricated and the mechanical characteristics of positive plates were measured. This study observed how the changes of content of Ca & Sn affect interface corrosion which is located in between grid & active materials and lead acid batteries as well. The mechanical characteristics of grid alloy is better when Ca is 0.05 wt.% then 0.1 wt.%. This study said that the corrosion rate between the active material based on the charge/discharge cycle of lead acid battery and grid interface is much faster than a grid which contains Sn. And furthermore, according to the study the rate 30 of Sn/Ca which is added to grid shows the best performance.

• 한국방사선학회논문지
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• 제10권7호
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• pp.539-543
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• 2016

본 연구는 진단용 X선 발생장치에서 조사야 외부의 산란선량을 감소시켜 환자의 피폭 선량을 감소시키기 위한 방법이다. 자체 제작한 $150{\times}190mm^2$ 납판을 콜리메이터 하단에 부착함으로써 조사야 이외의 부위에 도달하는 산란선량을 감소시키고자 하였다. 납판을 추가로 삽입 후 X선 관축방향인 X-축의 산란선량을 측정한 결과 26 ~ 36% 감소하는 것으로 나타났으며, 관축의 수직 방향인 Y-축 방향에서는 납판의 사용 유무에 따른 산란선량은 큰 변화를 나타내지 않았다. 이러한 결과는 콜리메이터 Shutter에 의해서 발생하는 산란선 보다는 초점 근방에서 발생하는 초점외 X선에 의한 산란선 영향이 크다는 것을 의미한다. 따라서 기존의 콜리메이터 하단에 추가로 납판을 설치하는 것이 조사야 외부의 X-축 산란선량을 감소시키는 방법으로 판단되어진다.

• 한국항공운항학회지
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• 제14권2호
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• pp.39-44
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• 2006

The unsteady vortex lattice method is used to model lead-lag in flapping motions of a rectangular flat plate wing. The results for plunging and pitching motions were compared with the limited experimental results available and other numerical methods. They show that the method is capable of simulating many of the features of complex flapping flight. The lift, thrust and propulsive efficiency of a rectangular flat plate wing have been calculated for various lead-lag motion and reduced frequency with an amplitude of flapping angle(20o). To describe a motion profile of wing tip such as elliptic, line and circle, the phase difference of flapping and lead-lag motion was changed. And the effects of the motion profile on the aerodynamic characteristics of the flapping wing are discussed by examination of their trends.

• 산업공학
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• 제21권4호
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• pp.418-434
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• 2008

This paper studied issues in decision making on the production control policy of a cathode plate manufacturing process in zinc refining plant. The present production system has a long lead time from raw materials (aluminum plate) to products (cathode plate) due to many WIP inventories. Because WIP inventories are stocked at each process and moved from one place to another frequently, they are the main cause of inefficiency in the process. In this paper, to solve this problem, several production control policies have been identified and studied. Several simulation models are used to compare the performances of these production control policies. The output lead time and WIP (Work In Process) of real production system are compared with those of simulation models. PUSH, CONWIP, DBR, KANBAN and CONWIP-DBR models have been used to simulate and review the optimized production control policy that achieves the target output quantities with decreased lead time and WIP. The simulation results of each production control policy show that CONWIP and CONWIP-DBR models are the good production control policy under the present production system. Especially in present production system, CONWIP with one parameter is easier control policy than CONWIP-DBR with two parameters. Therefore CONWIP has been selected as the best optimum production control policy. With CONWIP, lead time has been reduced by 97% (from 6,653 to 187 minute) and WIP has been reduced from 1,488 to 53, compared to the present system.