As the demand for p-type semiconductors increases, much effort is being put into developing new p-type materials. This demand has led to the development of novel new p-type semiconductors that go beyond existing p-type semiconductors. Copper iodide (CuI) has recently received much attention due to its wide band gap, excellent optical and electrical properties, and low temperature synthesis. However, there are limits to its use as a semiconductor material for thin film transistor devices due to the uncontrolled generation of copper vacancies and excessive hole doping. In this work, p-type CuI semiconductors were fabricated using the chemical vapor deposition (CVD) process for thin-film transistor (TFT) applications. The vacuum process has advantages over conventional solution processes, including conformal coating, large area uniformity, easy thickness control and so on. CuI thin films were fabricated at various deposition temperatures from 150 to 250 °C The surface roughness root mean square (RMS) value, which is related to carrier transport, decreases with increasing deposition temperature. Hall effect measurements showed that all fabricated CuI films had p-type behavior and that the Hall mobility decreased with increasing deposition temperature. The CuI TFTs showed no clear on/off because of the high concentration of carriers. By adopting a Zn capping layer, carrier concentrations decreased, leading to clear on and off behavior. Finally, stability tests of the PBS and NBS showed a threshold voltage shift within ±1 V.
연구에서는 새로 설계한 고분자 절연체 위에 전자 주개(Donor)-받개(Acceptor) 기반의 반도체성 공중합체인 Cyclopentadithiophene-alt-benzothiadiazole (CDT-BTZ)를 활성 반도체층으로 형성하여 제작한 고분자 반도체 전계효과 트랜지스터의 전기적 특성을 살펴보았다. 이 연구에서 제시하는 고분자 절연체 박막은 내열성과 전기절연성이 우수한 포스파젠과 멜리민 구조가 가교된 형태를 가지기 때문에 0.006 nm의 매우 평탄한 RMS 표면 거칠기를 가졌으며, 4.5 MV/cm 이상의 매우 우수한 절연강도와 1.55의 다소 낮은 유전 상수를 가진 것으로 측정되었다. 그리고, 고분자 절연 막과 계면을 이루는 CDT-BTZ D-A 타입 반도체성 공중합체 박막은 2.0 x 10-3 cm2/Vs의 선형영역 이동도와 1.0 x 10-3 cm2/Vs의 포화영역 이동도를 갖는 것으로 측정되었다. 이를 통해, 고분자 절연체 위에 형성된 CDT-BTZ 고분자 반도체 박막은 유연 전자회로의 스위칭 소자로 쓰이기에 충분한 잠재성이 있다고 여겨진다.
본 연구는 큰다닥냉이 어린잎 채소의 MA저장 중 OTR 필름 종류가 품질에 미치는 영향을 알아보고자 수행하였다. 플라스틱하우스에서 2주간 재배한 초장 10cm 내외의 큰다닥냉이 어린잎를 산소투과도가 1,300cc, 10,000cc, 20,000cc, 40,000cc, 그리고 80,000cc·m-2·day-1 ·atm-1인 OTR필름과 대조구인 미세천공필름(Ø 0.06cm, 36ea/100cm2)을 사용하여 포장하여 8oC에서 10일간 저 장하였다. 저장 종료일 모든 OTR필름 처리구의 생체중 감소율은 0.5%를 보였고, 대조구인 미세천공 필름은 1.3%의 감소를 나타냈다. 포장 내 산소농도는 20,000cc, 40,000cc, 그리고 80,000cc OTR필름 처리구에서 저장 중 18%이상의 농도을 유지하였고, 1,300cc OTR필름 처 리구는 저장 종료일 11%의 농도로 가장 낮게 유지되었 다. 이산화탄소 농도는 1,300cc와 10,000cc OTR필름 처리구에서 각각 4.5%와 3.4%의 수준으로 꾸준히 증가하였고, 다른 OTR필름 처리구는 1% 미만의 농도를 유지 하였다. 포장 내 에틸렌 농도는 저장 기간 중 1,300cc OTR 필름 처리구에서 3-5μL·L-1로 가장 높게 유지되었다. 1,300cc OTR필름 처리구에서 가장 낮은 이취와 가 장 높은 외관상 품질을 보였는데, 대조구를 포함한 다른 처리구들은 황화현상으로 인한 품질저하로 상품성을 상실하였다. 저장 종료일에 조사한 엽록소 함량과 Hue angle값은 1,300cc OTR필름 처리구에서 가장 높았으며, 황색도를 나타내는 b*값은 1,300cc OTR필름 처리구에 서 가장 낮았다. 따라서 MA저장 중 황화와 이취 억제효과가 우수한 1,300cc OTR필름이 큰다닥냉이 어린잎 채소의 포장에 적합하다고 판단된다.
In this paper, uniaxial tensile tests of ETFE films with three kinds of thicknesses(100, 200, 250μm) and two kinds of directions(machine direction & transverse direction) are performed and the tensile strength, the tensile strain at break and the Young’s modulus of ETFE films are compared for two kinds of specimen types(2 & 5). It could be figured out that there are no significant difference between tensile strengths of two specimen types but the tensile strain at break and the Young’s modulus of ETFE films are affected by the specimen types. And it is concluded that the uniaxial tensile test of specimen type 2 are more reliable than that of specimen type 5.
GaN is most commonly used to make LED elements. But, due to differences of the thermal expansion coefficient and lattice mismatch with sapphire, dislocations have occurred at about 109~1010/cm2. Generally, a low temperature GaN buffer layer is used between the GaN layer and the sapphire substrate in order to reduce the dislocation density and improve the characteristics of the thin film, and thus to increase the efficiency of the LED. Further, patterned sapphire substrate (PSS) are applied to improve the light extraction efficiency. In this experiment, using an AlN buffer layer on PSS in place of the GaN buffer layer that is used mainly to improve the properties of the GaN film, light extraction efficiency and overall properties of the thin film are improved at the same time. The AlN buffer layer was deposited by using a sputter and the AlN buffer layer thickness was determined to be 25 nm through XRD analysis after growing the GaN film at 1070˚C on the AlN buffer CPSS (C-plane Patterned Sapphire Substrate, AlN buffer 25 nm, 100 nm, 200 nm, 300 nm). The GaN film layer formed by applying a 2 step epitaxial lateral overgrowth (ELOG) process, and by changing temperatures (1020~1070˚C) and pressures (85~300 Torr). To confirm the surface morphology, we used SEM, AFM, and optical microscopy. To analyze the properties (dislocation density and crystallinity) of a thin film, we used HR-XRD and Cathodoluminescence.
한지형 마늘의 엽초유인 방법에 따른 마늘 엽 생육과 수량 에 미치는 영향을 구명하고자 관행유인, 비닐절개유인, 일시제 거유인 등 3처리를 두어 실험을 실시한 결과, 초장은 생육 초 기 일시제거유인에서 좋았으나, 생육 후기로 갈수록 차이가 없 었으며, 엽초경은 4월 상순까지는 비슷한 생육을 보였으나, 생 육후기로 갈수록 일시제거유인에서 저조하였다. 엽록소 함량 은 비닐 일시제거 유인에서 SPAD값이 46.0~62.5로 변화폭이 컸던 반면, 관행유인은 3.0(SPAD값)으로 변화폭이 적었다. 엽 초유인 방법별 토양온도는 관행 및 비닐절개 유인에서 최고· 최저 온도차가 비닐 일시제거유인에서는 14oC로 온도의 변화 폭이 컸다. 구중은 관행 및 비닐 절개 유인에서 무거웠으며, 1,000당 투하노동력은 비닐절개구와 비닐 일시제거구에서 관 행 66.5시간/2인 대비 각각 17.3%와 18.3%의 점감효과가 있 었고, 1,000당 수량은 비닐절개 유인이 751 kg로 관행유인 686 kg에 비해 9% 증수되었다.
As film products are more frequently used from producing traditional flexible packing products to high-tech electronic products, requested higher level of quality. Most film products are made in the shape of roll-type finished goods, so various quality problems are addressed related with their characteristics of shape. Thickness of film products is one of the most common and important quality problems. Particularly the Degree of thick smoothness is more important than other thickness issues, because it causes many secondary issues of thickness-related quality problems like wrinkles or faulty windings. Thick smoothness must be controlled in both horizontal and vertical direction. In this paper, HOQ (house of quality) was built to interpret VOC (voice of customers) to CTQs (critical to quality). To decide priorities of VOC and CTQs, both techniques are applied. One is AHP (analytic hierarchy process) with pairwise comparison. The other is an absolute weight calculation method with level-up rate. From the result of HOQ, it is certain that the thick smoothness is the most important CTQ in film manufacturing industry. Finally, this paper presents how to monitor and improve repetitive coincidence of microscopic deviation of thickness in some special vertical points.
식용꽃은 일반적으로 개화된 상태에서 수확, 줄기가 없는 상태에서 유통되므로 저장성이 급격히 저하되는 것 이 단점이다. 이에 본 연구는 여러 종류의 포장 필름 중식용꽃의 상온유통을 위한 효과적인 포장재를 선발하 기 위하여 실시하였다. 식용꽃 재료로는 꾸준한 수요로 연중생산 되고 있는 금어초, 금잔화, 비올라, 패랭이, 팬지, 한련화 등 총 6종으로 실시하였다. 유통 시 적용할 포장 필름을 선 발하기 위하여 0.03mm 두께의 polyethlene (PE) film와 polypropylene (PP) film을 대조구로 하였으며 필름 표면의 미세한 천공을 통해 산소투과도 (OTR-Oxygen Transmission Rate)를 조절할 수 있는 6가지 종류의 필 름인 PE 0.03 mm (LF10, LF20, LF30), PP 0.0 3mm (LF10, LF20, LF30) 등을 이용하였다. 식용꽃의 상온 유통시 금잔화, 한련화는 필름별 차이가 없었으며, 비올라, 패랭이, 팬지는 PP (LF10)필름이 효과 적인 것으로 나타났다. 비올라, 패랭이, 팬지는 꽃잎이 바깥쪽부터 말리기 시작하면서 노화 증상이 나타났고, 한련화는 꽃잎 무름과 변색, 금어초는 갈색 점이 나타 나면서 부패증상이 나타나는 등 식용꽃 종류별로 노화 유형이 뚜렷하게 구분되었다.
Thermoelectric-thick films were fabricated by using a screen printing process of n and p-type bismuth-telluride-based pastes. The screen-printed thick films have approximately 30 in thickness and show rough surfaces yielding an empty gap between an electrode and the thick film. The gap might result in an increase of an electrical resistivity of the fabricated thick-film-type thermoelectric module. In this study, we suggest a conductive metal coating onto the surfaces of the screen-printed paste in order to reduce the contact resistance in the module. As a result, the electrical resistivity of the thermoelectric module having a gold coating layer was significantly reduced up to 30% compared to that of a module without any metal coating. This result indicates that an introduction of conductive metal layers is effective to decrease the contact resistivity of a thick-film-typed thermoelectric module processed by screen printing.
To determine an operational condition of an adhesion-type oil skimmer, it is important to estimate the withdrawal rate for a given driving velocity of the skimmer and material properties of the oil. As a theoretical model for this problem the formation of an oil film on a vertically driven flat plate is investigated. The previous steady-state analysis made in the field of coating industry are reviewed. These studies have been made under the assumptions of small Reynolds and capillary number, which is adequate for coating process but not for oil skimming. An alternative analysis based on the linear stability theory is made. Comparisons with the experimental results reveal that the stability analysis gives a correct estimation of the withdrawal rate for high capillary number at which the previous theory losses its validity.
박막 형 가스 센서의 막 두께가 가스 감지 특성에 미치는 영향을 단순화된 모델로부터 수식으로 유도하여 해석하였고, 그것을 SnO2와 CuO-SnO2 박막의 h2S 감응 특성에 대한 실험 결과에 적용하였다. 유도된 수식으로부터 박막 가스 센서의 가스 감지 특성은 가스의 박막 안으로의 확산성에 크게 의존하며, 그 가스 확산성은 박막의 두께, 가스의 센서 재료의 반응성, 작동 온도 등에 의해서 결정됨을 알 수 있었다. 또한 이 수식은 CuO-SnO2 박막의 h2S 감응 특성에 대한 실험 결과와 비교적 잘 일치하였고, CuO-SnO2 박막과 SnO2 박막의 서로 판이한 h2S 감응 특성에 대한 설명에 적용되었다. 이로부터, 일반적인 산화물 반도체식 가스 센서의 가스 감지 특성이 가스 확산성에 의해서 어떻게 지배되는가를 구체적으로 제안하였다.
This paper is containing two study. The one is a land treatment of sewage sludge reduction through the indirect heating method and the other verifies conversion possibility of sludge organic matter to auxiliary fuel, steel thermal insulation material, byproduct fertilizer compost and find the suitable recycling method for J city. It was confirmed that about 88 percent of weight reduction for transportation efficiency and method verification. The analysis result of the carbonized product component showed the average low heating value of about 2,850 kcal and the moisture content of 1.4% which means the sludge is suitable as a fuel.
This study was carried out to investigate the effect of no-tillage on sequential cropping supported from recycling of first crop ridge on the growth of pepper plant and physical properties of soil under green house condition.1. Degree of crack on soil by tillage and no-tillageSoil cracks found in ridge and not found in row. At five months of tillage, crack number and crack length in length ridge were 3 and 37~51 cm in tillage. Maximum width and maximum depth in length ridge were 30 mm and 15.3cm in tillage. Crack number and crack length in width ridge were 7.5 and 7~28 cm in tillage. Maximum width and maximum depth in width ridge were 29 mm and 15.3 cm in tillage. At a year of no-tillage, crack number and crack length in length ridge were 1.0 and 140~200 cm in tillage. Maximum width and maximum depth in length ridge were 18 mm and 30 cm in a year of no-tillage. Crack number and crack length in width ridge were 11 and 6~22 cm in a year of no-tillage. Maximum width and maximum depth in width ridge were 22 mm and 18.5 cm in a year of no-tillage. Soil crack was not found at 2 years of no-tillage in sandy Jungdong series (jd) soil. Soil crack was found at 7 years of no-tillage in clayish Jisan series (ji) soil.2. Penetration resistance on soilPenetration resistance was increased significantly at no-tillage in Jungdong series (jd). Depth of cultivation layer was extended at no-tillage soil compared with tillage soil. Penetration resistance of plow pan was decreased at 1 year of no-tillage compared with than tillage soil. Penetration resistance was linearly increased with increasing soil depth at tillage in Jisan series (ji). Penetration resistance on top soil was remarkably increased and then maintained continuously at no-tillage soil.3. Drainage and moisture content of soilMoisture content of ridge in top soil was not significant difference at both tillage and no-tillage. Moisture content of ridge in 20 cm soil was 14% at no-tillage soil and 25% at tillage soil.4. Change of capacity to retain water in soilCapacity to retain water in top soil was not significant difference at 1 bar both tillage and no-tillage. Capacity to retain water in soil was slightly higher tendency in 1 year and 2 years of no-tillage soil than tillage soil. Capacity to retain water in soil was increased at 15 bar both tillage and no-tillage. Capacity to retain water in subsoil was slightly higher tendency at 1 bar and 3 bar in 2 years of no-tillage than tillage soil and a year of no-tillage soil.
Vibrotactile actuators for small consumer electronic products, such as mobile devices, have been widely used for conveying haptic sensation to users. One of the most important things in vibrotactile actuators is to be developed in the form of thin actuator which can be easily embedded into mobile devices and to provide vibrotactile signals with wide frequency band to users. Thus, this paper proposes a thin film type haptic actuator with an aim to convey vibrotactile information with high frequency bandwidth to users in mobile devices. To this end, a vibrotactile actuator which creates haptic sensation is designed and constructed based on cellulose acetate material. A cellulose acetate material charged with an electric potential can generate vibration under the AC voltage input. It is found that the motion of the actuator can have concave or convex shape by controlling a polarity of both charged membranes and the actuator performance can be modulated by increasing level of biased electric potential. The experiment clearly shows that the proposed actuator creates enough output force to stimulate human skin with a large frequency bandwidth and to simulate various vibrotactile sensations to users.
하대두형 품종에 대하여 파종기를 달리하고 비닐멀칭을 했을 때 생육 및 수량에 미치는 영향을 규명코져 다마미도리 지두를 4월 13일부터 10일 간격으로 4파종기로 하고, 비닐로 멀칭과 무멀칭으로 하여 시험한 결과를 요약하면 다음과 같다. 1. 출현기는 멀칭을 할 경우 무멀칭에 비하여 촉진되어 4월 13일 파종구는 11일 축진되었다. 개화일수도 멀칭을 할 경우 평균 6일이 단축되었고, 4월 13일 파종구는 12일이 단축되었다. 2. 멀칭구는 무멀칭에 비하여 주경장이 컸으며, 주경절수 및 분지수도 많았을 뿐 아니라. l0a당 건경중도 많았다. 평균 100립중은 차가 없었다. 멀칭의 경우 늦게 파종한 구에서 주경장이 컸고, 주경절수 및 분지수도 많았을 뿐 아니라 건경중도 높았으며, 100립중도 무거웠다. 이러한 현상은 일찍 파종한구에서 미이라병의 리병입률이 높았기 때문이다. 무멀칭의 경우는 멀칭구와 같은 경향을 보이지는 않았다. 3. 멀칭구에서 미이라병의 리병입율이 높으면 자반병 리병입율은 낮아졌다. 무멀칭구는 멀칭구에서와 같은 경향은 보이지 않았다. 4. 멀칭구에서는 무멀칭구보다 평균 20%가 증수되었고, 파종기별로 보면 일찍 파종한 구에서 미이라병에 대한 리병정도가 심하여 수량이 낮았고, 늦게 파종한 구에서 수량이 높았다.