Most fishing nets used in fish cage aquaculture are made of synthetic fibers such as polyamide (PA) and polyethylene (PE). Therefore, it is challenging to maintain the internal volume of the fish cage due to biofouling, which can increase the load on the cage or reduce dissolved oxygen levels by impeding smooth current flow. To address this issue, research has been conducted to replace conventional synthetic fiber cage nets with brass nets, demonstrating certain benefits such as improved productivity and ease of fish cage management. However, given the need for a more thorough examination of brass fishing net weaving technology and performance, this study assessed the optimal weaving method for brass fishing nets to be used in fish cages. Additionally, it provided essential data for the practical application of brass fishing nets by evaluating their weight, tensile strength, elongation, fatigue resistance, and wear resistance. The study concluded that weaving brass fishing nets using the chain link method ensures durability, ease of installation, and compact storage in a scroll-like form. Moreover, due to their superior fatigue and wear resistance properties, brass nets can offer increased utility if appropriate net diameter and length are selected to compensate for their higher weight per unit area and relatively higher cost compared to existing fiber fishing nets.

이 논문은 브라스에서 리듬 그루브의 영향을 끼치는 요소들을 분석하여 연주자와 프로듀서들이 좀 더 다양하고 그루브한 연주를 하는 것에 도움이 되는 것을 목적으로 연구되었다. 연구 방법은 그루브에 영향을 끼칠 수 있는 요소 중에서 브라스에 적용 가능한 음정의 변화, 음길이의 변화, 음역대의 변화, 악센트의 변화, 전체 볼륨의 변화, BPM(빠르기)의 변화, 톤의 변화 총 7개 요소를 각각 변화가 없는 기준 샘플과 변화된 음원 샘플로 만들어 실험군에게 듣게 한 후 리듬 그루브의 변화를 가장 크게 느낀 요소를 선택하는 방식으로 제작 되었다. 연구 결과 리듬 그루브의 변화에 가장 많이 영향을 끼치는 요소 중 유의미한 상위 3개의 결과는 음길이의 변화 (54.5%), 악센트의 변화 (22.8%), BPM의 변화 (13.9%)로 도출됐으며 그 중 음길이의 변화 (54.5%)가 압도적으로 높게 나타났다. 흥미로운 것은 악센트와 빠르기(bpm)의 변화에서 보컬 전공은 각각 15%, 10%로 기악, 작곡전공의 8%, 4%에 비해 리듬 그루브의 변화를 더 느낀 것으로 결과가 도출되었다.

The aim of this study is to consider the effect hydrogen on dezincification behavior of Cu-Zn alloys. The investigations include microstructural observations with scanning electron microscope and chemical composition analysis with energy dispersive spectrometer. The dezincification layer was found to occur in high pressure hydrogen atmosphere, not in air atmosphere. In addition, the layers penetrated into the inner side along the grain boundaries in the case of hydrogen condition. The shape of the dezincification layers was porous because of Zn dissolution from the α or β phase. In the case of stress corrosion cracks formed in the Cu-Zn microstructure, the dezincification phenomenon with porous voids was also accompanied by grain boundary cracking.

The food components of red sea bream(Pagrus major) cultured in copper alloy(brass) net(BN) and nylon net(NN) cages for nine months were investigated. The body weight was 234.9g at the beginning of the culture(the young fish), and then 692.1g(BN group) and 549.3g(NN group) at the fish cultured for nine months(the nine-month culture fish). The moisture content of the edible portion of the fish was higher in the young fish than in the nine-month culture fish. On the contrary, the lipid content was higher in the latter (9.1-10.6%) than in the former (7.6%).　 The lipid content in the nine-month culture fish was slightly higher in the BN group compared to the NN group. There was little difference in protein content between the young fish and the nine-month culture fish, or between the BN and NN groups. There was a slightly higher level of copper content in the liver (5ppm in the young fish and 5-6ppm in the nine-month culture fish) compared to the edible portions (1ppm in the young fish and 3-4ppm in the nine-month culture fish), but no difference was evident between the BN and NN groups. The prominent fatty acids were 16:0, 18:1n-9, 22:6n-3, 16:1n-7, 18:2n-6, 20:5n-3, and 18:0 in the edible portions of the young and cultured fish. The n-3 fatty acid content was slightly richer in the BN group.

Ceramic pigments were developed by using 4 kinds of Brass scraps. Each Brass scraps were mixed with same weight-ratio of Husk ash, and fine-ground by Rotate ring mill(RRG-120, Armstech industrial. co. Ltd, Korea) after firing at 900℃, 1000℃ and 1100℃. As a result, analysis of particle size of synthetic pigments by particle size analyser, they are 3μm as average. The resulting pigments were characterized by using XRD, FT-IR, SEM Structure of the crystals are Zn2SiO4,, and ZnO, Cu2O, CuO, and cristobalite are existed and particles' shape are plate or needle. As a result of analysis of chemical composition by XRF, synthetic pigments have high SiO2 and CuO content and have SnO2, ZnO and NiO, too. 1wt%, 3wt% and 5wt% pigments were added in each lime glaze, lime-barium glaze and lime-magnesia glaze, and fired at oxidation and reducing atmosphere to figure hue in glazes out. As a result of analysis of color, chroma and brightness by UV, colors of glazes fired at oxidation atmosphere turned into green from sky blue, and colors of glazes fired at reducing atmosphere turned into pink and red.

황동 개재물이 있는 Al 정사각판의 고유진동수는 혼합법칙을 이용하여 해석되었다. 혼합법칙에 의한 고유진동수는 개재물의 크기에 따른 유효 내평면 파동속도와 무차원 진동수 매개변수와의 곱으로 이루어진다. 해석모델은 외팔형, 2변 고정-2변 자유형, 3변 고정-1변 자유형 및 4변 고정형의 황동 개재물이 있는 4가지의 Al판이다. 자유단이 1개 이상 존재하는 경계조건에서 개재물이 판의 중앙에 위치하였을 때 개재물에 대한 판 전체의 면적비가 1/9 이하이면 혼합법칙 및 유한요소 해석에 의한 고유진동수는 10% 이내로 잘 일치하였다 4변 고정형 경계조건을 제외하고 3가지 경계조건에서 개재물이 판중앙에 있을 경우 개재물의 크기가 커짐에 따라 개재물이 있는 판의 고유진동수는 낮아짐을 알았다. 또한 개재물의 밀도가 판의 밀도보다 작을 때, 개재물 크기가 커짐에 따라 개재물이 있는 판의 고유진동수는 높아진다.

This study intend to make easy modification, even if there is a new job or structure change, by modularizing program and computerize and automation of production control management used in CIM. under the condition where manager control production on the j

Al-brass is usually used as the tube material of vessel's heat exchanger for seawater cooling system because it has high thermal conductivity and good mechanical properties and high corrosion resistance due to cuprous oxide (Cu20) layer against seawater. However, Al-brass tubes of heat exchanger for vessel at the actual environment is reported that local corrosion such as stress corrosion cracking occurred by synergism effect between mechanical factor and corrosion environment In this paper, the effect of corrosion environment on the stress corrosion cracking of Al-brass in various NH4OH of 3.5% NaCl solution, under flow by constant displacement tester. Based on the test results, the behavior of polarization, stress corrosion crack propagation and dezincification phenomenon of Al-brass are investigated. The main results are as follows：(1) Increasing range of potential from open circuit potential to repassivation gets lower, as the contain rate of NH4OH gets higher. (2) As contain rate of NH4OH gets higher, SCC of Al-brass is become activation but the protection film(Cu20) of Al-brass is created in 3.5% NaCl solution. (3) According as content of NH4OH increases in 3.5% NaCl solution, the dezincifiction area is spread. It is concluded that dezincification occurred by localized preferential anodic dissolution at stress focusing region.