• 농업과학연구
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• 제49권1호
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• pp.151-162
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• 2022

This study was conducted to develop a rail-type boom sprayer, performing safe spraying with improved ergonomic postures during pesticide spraying of agro-photovoltaic power system. The sprayer was designed to reduce labor cost and to be safe from pesticide exposure, and was analyzed through a comparison with a conventional spray method. The rail-type boom sprayer, consisted of a self-propelled spray and hose winder, hose, and boom sprayer parts, was designed to automatically pull and spray in the vertical and horizontal directions. The performance of the sprayer for an agro-photovoltaic power system was appropriate. From the analysis of postures with the Ovako Working posture Analysis System (OWAS), Rapid Entire Body Assessment (REBA), and Rapid Upper Limb Assessment (RULA) methods, the musculoskeletal risk factors to the body using the rail-type boom sprayer were less than those with the conventional power sprayer. In addition, the possibility of pesticide poisoning was reduced compared to the conventional power sprayer. The working capacity with the rail-type boom sprayer was more than five times greater, compared with the conventional power sprayer. After performing pesticide spraying with the rail-type boom sprayer, the labor cost was reduced to 42,750 won·yr^-1, which was 90% (402,750 won·yr^-1) less than the cost with the use of a conventional power sprayer (445,500 won·yr^-1).

• 한국건축시공학회지
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• 제13권6호
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• pp.594-601
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• 2013

One of the important problems associated with building demolition is the dust generated during the work. The only way to reduce the demolition dust is to use a dust net during water spraying. However, it is difficult to supply the necessary amount of water to remove demolition dust, thus making it difficult to apply this method on a demolition site. This work attempted to find an alternative approach to dust removal by incorporating surfactant and high range AE water reducer in the water being sprayed. Through the experiment, it was found that the addition of surfactant did not contribute to the removal of demolition dust. However, the use of high range AE water reducer showed better performance than spraying plain water, indicating that some amount of demolition dust had been adsorbed on the high range AE water reducer.

• 설비공학논문집
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• 제14권10호
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• pp.786-791
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• 2002

An experimental study on the behavior of the water hold-up by spraying of a fin-and-tube heat exchanger with regard to the surface characteristics, i.e., contact angles, was conducted. The dynamic contact angles (DCA) were measured, and water hold-up by spraying (WHS) was conducted in the experiment. It is found that heat exchanger surface characteristics, spray pressure, spray water temperature and heat exchanger surface temperature play an important role in WHS. In order to evaluate relationship between WHS and surface characteristics, test conditions are determined through a contour analysis. A correlation was proposed to predict WHS as a function of DCA. With its test efficiency and consuming time, the prediction method can be used to evaluate WHS performance.

• 한국축산시설환경학회지
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• 제11권2호
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• pp.111-116
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• 2005

축산 농가용 차량소독기의 노즐 분무성능과 균등분포율을 알아보고 적합성을 판단하고자 각 사별, 압력별 노즐 분무량을 측정하였다. 3 Mpa 분무압력에서 분무량은 TK사의 경우 1,605ml, TK-II 경우 2,020ml, JA사 노즐의 경우 1,150ml로 나타났으며, IS사의 경우 795ml로 나타났다. JA사의 경우 1,150 ml, IS사는 795 ml로 나타났다. 모든 압력에서 분무량은 TK-II, TK-I, JA 및 IS사 순으로 많았으며, TK-II사와 IS사간 분무량은 약 3배 차이를 보였다. 균등분포율을 알아보기 위한 압력별 측정결과는 모두 양 옆의 1, 2, 8, 9번 용기는 평균에 모자라는 분무량을 보였다. 그 외 3번 용기에서 7번 용기까지는 TK사의 경우 비교적 균일한 분무분포를 나타냈지만, JA사와 IS사의 경우 TK사 보다는 중앙이나 한쪽으로 분무량이 치우치는 경향을 나타냈다. 최적의 차량 소독기를 설계하기 위해서는 사용되는 노즐의 분사량, 균등분포율을 고려한 노즐 선택, 노즐 간격, 진행하는 차량의 속도 등을 우선적으로 고려하여 설계할 필요가 있을 것으로 판단되었다.

• Journal of Welding and Joining
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• 제24권5호
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• pp.57-61
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• 2006

For the production of functional $TiO_2$-biodegradable plastic (polybutylene succinate:PBS) composite material with photocayalytic activity, we attempted to prepare $TiO_2$ coatings on PBS substrate by HVOF and plasma spraying techniques under various conditions. The microstructures of coatings were characterized with SEM and XRD analysis, and the photocatalytic efficiency of coatings was evaluated by the photo degradation of gaseous acetaldehyde. The effects of primary particle size and spraying parameters on the formation behavior, photocatalytic performance of the coatings have been investigated. The results indicated that for both the HVOF sprayed $P_{200}$ and $P_{30}$ coatings, the high anatase ratio of 100% can be achieved regardless of fuel gas pressure. On the other hand, the HVOF sprayed $P_7$ coating exhibited a largely decreased anatase ratio (from 100% to 49.1%) with increasing the fuel gas pressure, which may be attributed to much higher susceptibility of heat for 7 nm agglomerated powder. HVOF sprayed $P_{200}$ and $P_{30}$ coatings show better performance as compared to that of plasma sprayed $P_{200}$ coatings owing to the higher anatase ratio. However, the HVOF sprayed $P_7$ coatings did not show the photocatalytic activity, which may result from the extremely small reaction surface area to the photocatalytic activity and low anatase ratio.

• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.42-47
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• 2006

This study was conducted to investigate the efficacy of surface spraying of antimicrobial solutions, oil and application of both on performance of broiler chicken under heat stress and reared on leaves and ground corn cobs as two alternative bedding materials. Six hundred seventy five day-old straightrun Arian broiler chicks were randomly assigned to 45 pens (at density of $0.09m^2/bird$) in an open sided partially-controlled shed. Three bedding materials viz. wood shavings (WS), ground corn cobs (GCC) (1.5 cm in length) and leaves were subjected to surface spraying of oil ($0.4L/m^2$ animal food grade sunflower oil), anti microbial solutions (3%) and mix treatment of both. Data on performance traits, incidence of breast and food pad lesions and litter characteristics were gathered and analysed in an appropriate factorial arrangements. Body weight at 56 d, feed intake up to 14 d, litter moisture at 28 d, litter pH at 14 d and litter temperature at 14 and 56 d were significantly influenced by litter type (p<0.05). Litter treatment revealed significant impact on body weight at 28, 42 and 56 d, feed intake during 29-42 and 1-42 d, mortality up to 56 d, litter temperature at 28 and 56 d, and litter pH at 28 and 56 d. Leaves and ground corn cobs have shown good potential as alternative bedding materials for rearing broilers. Surface spraying of antimicrobial solutions, oil and applying both were not effective tools to promote the broiler's health and performance. Meat type poultry growers and integrators are considered as primary audiences of the results achieved.

• 한국해양공학회지
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• 제35권1호
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• pp.24-37
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• 2021

As one of the development directions of high-performance ships to reduce greenhouse gas emissions, there is research on high-performance propellers. However, in the case of conventional screw propellers, as they have been studied for a long time, there is a limit to improving efficiency only by depending on the conventional design and analysis methods. In this study, we tried to solve the problems using the Coanda effect by spraying a jet on the surface of the hydrofoil. The Coanda hydrofoil consists of a tunnel and jet slit to make jet flow. The computation was performed for each tunnel and slit position, and the efficiency according to the geometry of the hydrofoil was analyzed. In addition, a study on the 3D geometry change was conducted to analyze the performance according to the span direction spraying range and hydrofoil shape. As the height of the slit and the diameter of the tip were lower, when the slit is located in the center of the hydrofoil, the lift force increased and the drag force decreased. The increase rate of lift-to-drag ratio was different according to the shape of the hydrofoil, and the efficiency of the spraying condition of 0.1S-0.5S, which had the least effect on the vortex at the tip of the blade, was high for all 3D hydrofoils. When the geometry of the slit was optimized, and also the shape and spray range of the hydrofoil in 3D was considered, the efficiency of the jet sprayed hydrofoil was increased.

• 드라이브 ㆍ 컨트롤
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• 제21권2호
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• pp.53-64
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• 2024

Global population growth has resulted in an increased demand for food production. Simultaneously, aging rural communities have led to a decrease in the workforce, thereby increasing the demand for automation in agriculture. Drones are particularly useful for unmanned pest control fields. However, the current method of uniform spraying leads to environmental damage due to overuse of pesticides and drift by wind. To address this issue, it is necessary to enhance spraying performance through precise performance evaluation. Therefore, as a foundational study aimed at optimizing drone-based pest control technologies, this research evaluated water-sensitive paper (WSP) via density map estimation using convolutional neural networks (CNN) with a encoder-decoder structure. To achieve more accurate estimation, this study implemented multi-task learning, incorporating an additional classifier for image segmentation alongside the density map estimation classifier. The proposed model in this study resulted in a R-squared (R²) of 0.976 for coverage area in the evaluation data set, demonstrating satisfactory performance in evaluating WSP at various density levels. Further research is needed to improve the accuracy of spray result estimations and develop a real-time assessment technology in the field.

• 자원리싸이클링
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• 제26권2호
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• pp.56-65
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• 2017

본 연구는 금속용사 공법의 희생양극재료인 Zn, Al의 구성비율에 따른 방식성능에 관한 실험적 연구이다. 금속용사의 분사 방법으로는 Arc 금속용사 공법을 사용하였으며, Zn, Al의 구성비율 및 코팅 두께를 달리하여 시편을 제작하였다. 실험방법으로는 CASS 염수분무 실험에 준하여 실시하였으며 CASS 염수분무 시작일로부터 1, 3, 7, 15일 동안 실험체의 부식상태를 육안으로 관찰하였다. 본 연구결과 Al의 함량이 증가함에 따라 부식에 대한 방식성능이 증가함을 확인하였으며, 코팅두께 $80{\mu}m$ 이상을 확보하여야만 우수한 방식성능이 발현되는 것을 확인하였다. 또한 CASS 실험 후 금속용사 실험체의 단면 형상 관찰하기 위해 SEM 분석을 실시하였으며, 분석결과 Al의 함량이 증가할수록 금속용사 코팅층의 열화가 감소하는 것을 확인하였다.

• 한국건축시공학회지
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• 제23권4호
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• pp.429-440
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• 2023

이 연구에서는 방수공사의 장비 활용 시공기술을 통해 작업환경 개선으로 인한 작업자의 사고방지 및 안전을 확보하고, 장비의 활용에 따른 작업 효율성 증대 및 품질을 개선시키며 더불어 기능공 확보의 어려움을 해소하는 것을 목적으로 하고 있다. 시멘트 액체 방수 뿜칠장비를 활용함으로써 부착성능이 약 20% 향상하고 작업속도가 2배 상승하였다. 프라이머 뿜칠 장비를 활용함으로써 침투성능과 부착성능이 약 2배 개선되는 효과를 보였고, 작업속도가 약 2배 상승하였다. 우레탄 뿜칠 장비를 활용함으로써 동일한 도막두께를 확보하는데 작업량을 1/3로 단축할 수 있으며, 부착강도는 약 1.4배 증가하는 결과를 나타내었고, 작업성이 약 1.4~1.5배 향상되었다. 이러한 결과로부터 장비 작업 시 품질향상과 더불어 작업효율이 증대되고, 수작업 환경에서 자주 발생하는 안전사고를 방지함으로써 안전 환경 조성에 기여할 수 있다. 또한 기능공 수급에 대한 어려움 해소가 가능할 것으로 판단된다.