At Pyropia farms, organic acid treatments have enhanced productivity and quality by removing pest algae (such as Ulva spp. and diatoms) and reducing the occurrence of diseases. Ulva spp. attaches to the Pyropia nets competing for inorganic nutrients & space and diminishing productivity. Additionally, the presence of attached contaminants (such as diatoms and middy particles) on the Pyropia nets negatively affects the quality of Pyropia. This study investigated the effects of removing Ulva linza and washing the Pyropia yezoensis nets using an activating treatment agent (organic acid and highly saline solution) with an air bubble device. The results of measuring the dead cell ratios after treatment under different conditions showed that the dead cell ratio of U. linza did not significantly increase when the air bubble device combined the activating treatment agent with the activating treatment agent alone. When washing the P. yezoensis nets, the air bubble device was about 19-37% more effective than the activating treatment agent alone. The findings of this study suggest that the air bubble device enhances the efficacy of the activating treatment agent, resulting in the effective cleaning of the Pyropia nets.

본 연구는 계란의 품질 유지를 위한 온도변화의 영향을 평가하고 실제 유통 환경에서 난각에 Salmonella Enteritidis 가 오염된 비세척란의 적절한 온도 관리 방법을 결정하고 자 하였다. Salmonella Enteritidis가 접종된 비세척란은 총 7일간 25oC 항온보관 및 5가지의 다른 온도변화조건에서 보관하였다. 온도변화조건은 계란을 초기 25oC에서 보관 중 온도를 10oC 또는 35oC로 변화하였다. 보관 중 기실의 높이, 중량감소율, 비중 및 농후난백 비율을 1일 간격으로 평가하였다. 기실의 높이, 중량감소율, 비중은 25oC 보관 3일 및 4일차에 10oC로 온도를 낮추었을 때 초기값이 유 의적으로 보존되었다. 농후난백 비율은 초기 값과 비교하 였을 때 보관 조건에 따른 유의한 차이를 나타내지 않았 다. 이러한 결과는 25oC 보관 3일 및 4일차에 10oC로 낮 추는 것이 실제 유통 시 비세척란의 안전관리에 적합함을 시사하였다.

The purpose of this study was to investigate the effects of sterilization, storage period and washing yuzu, according to the washing method, during the storage period. The results showed that the fungus size increased as the storage period increased, and no mold occurred in the yuzu washed with ozone water until 20 days. After 30 days of storage, a mold of 124.1±13.9 mm2 was observed. The no-treatment sample had a fungus of 814.5±72.8 mm2 in size on day 0 and the fungus the largest fungus was 6,362±636.7 mm2 on day 30. In the case of water treatment, the fungus was 286.4±31.5~4,836.4±484.6 mm2 in size. The results of the study confirmed that washing yuzu with ozone water has a sterilizing effect.

Peanut is a well-known food allergen that causes adverse reactions ranging from mild urticaria to life-threatening anaphylaxis. Consumers suffering from peanut allergies should thus avoid consuming undeclared peanuts in processed foods. Therefore, effective cleaning methods are needed to remove food allergens from manufacturing facilities. To address this, wet cleaning methods with washing water at different temperatures, abstergents (peracetic acid, sodium bicarbonate, dilute sodium hypochlorite, detergent), and cleaning tools (brush, sponge, paper towel, and cotton) were investigated to remove peanuts from materials used in food manufacture, including plastics, wood, glass, and stainless steel. Peanut butter was coated on the surface of the glass, wood, stainless steel, and plastic for 30 min and cleaned using wet cleaning. The peanut residue on the cleaned surfaces was swabbed and determined using an optimized enzyme-linked immunosorbent assay (ELISA). Cleaning using a brush and hot water above 50oC showed an effective reduction of peanut residue from the surface. However, removing peanuts from wooden surfaces was complicated. These results provide information for selecting appropriate materials in food manufacturing facilities and cleaning methods to remove food allergens. Additionally, the cleaning methods developed in this study can be applied to further research on removing other food allergens.

Electroless plating is widely utilized in engineering for the metallization of insulator substrates, including polymers, glass, and ceramics, without the need for the application of external potential. Homogeneous nucleation of metals requires the presence of Sn-Pd catalysts, which significantly reduce the activation energy of deposition. Therefore, rinsing conducted during Sn sensitization and Pd activation is a key variable for the formation of a uniform seed layer without the lack or excess of catalysts. Herein, we report the optimized rinsing process for the functionalization of Sn-Pd catalysts, which enables the uniform FeCo metallization of the glass fibers. Rinsing enables good deposition of the FeCo alloy because of the removal of excess catalysts from the glass fiber. Concurrently, excessive rinsing results in a complete removal of the Sn–Pd nucleus. Collectively, the comprehensive study of the proposed nanomaterial preparation and surface science show that the metallization of insulators is a promising technology for electronics, solar cells, catalysts, and mechanical parts.

The global power generation industry is becoming a key power generation industry with gas power generation and renewable energy solar power generation. This research aims to focus on solving two problems as a method to improve the solar light collection efficiency among fixed variable deformation methods. Maintaining the proper temperature of the water injection device through automatic temperature detection to solve efficiency degradation, and establishing an automatic operation system by finding the optimal angle for each season, are intended to derive a value that can represent the optimal power generation.

In this study, we compared the microbial reduction effects of drying, hot water, and microwave sterilization in scourers and dishcloths to suggest a most suitable sterilization method. Three scourer types (silver, copper, and mesh) were used, and three dishcloth types (silver, bamboo, and cotton) were used. Drying time dependent reduction in Escherichia coli was high in silver and copper scourers, but minimal bacterial reduction was obtained against Bacillus cereus in all scourers and dishcloths. In scourers, E. coli was not detected after ≥30 s of hot water sterilization at 77oC, and B. cereus was not detected after ≥60 s of hot water sterilization at 100oC. In dishcloths, E. coli was not detected after hot water sterilization at 77oC for ≥30 s, but B. cereus was detected after hot water sterilization at 100oC for ≥60 s. In scourers, E. coli was not detected after microwave sterilization at 700 W for 3 min, but B. cereus was detected. In dishcloths, E. coli was not detected after microwave sterilization with 700 W for ≥1 min, but B. cereus was detected in the cotton dishcloth even after sterilization for 3 min. In conclusion, the use of antimicrobial scourers (silver and copper) and dishcloths (silver and bamboo) are not sufficient to reduce the microbial contamination. The guideline provided by the Ministry of Food and Drug Safety suggesting dishcloth sterilization via hot water at 100oC for 30 s was also found to be insufficient. Based on our research, we suggest that the most effective methods of microbial management are submerging scourers in hot water at 100oC for ≥1 min, and sterilizing dishcloths for ≥3 min using a 700 W microwave.

대표적인 매실 가공제품인 당절임식품의 제조과정은 먼저 선별기로 낙과, 찰과 등을 분리·제거하고 세척하여 수 분을 제거한 후 길이방향으로 6-7 조각으로 절단하여 씨를 분리한다. 그러나 매실은 수확기가 고온기로 수확기간 이 짧아 장기저장이 어려우며 생과로 이용할 수 없어 수확 즉시 가공해야 한다. 이와 같은 매실 특성 때문에 수확 즉시 안정적인 가공을 위해서는 모든 공정의 기계화가 뒷받침되어야 한다. 따라서 본 연구에서는 세척부터 완제품 포장까지 매실 절임 제품 생산 전과정 기계화에 필요한 기초자료를 얻기 위해 매실 세척 및 탈수 시스템을 제작하 고 시험하였다. 본 연구에서 제작한 세척장치는 세척조에서 순환펌프에 의해 분출되는 물줄기와 터지는 공기방울에 복합적으로 세척되며, 상승컨베이어로 이송되면서 헹굼세척이 된다. 세척수는 보조 물탱크의 거름망에 이물질이 걸 러져 재순환 된다. 탈수장치는 세척된 매실을 매시벨트 컨베이어로 이송시키면서 송풍기의 고속·고풍량 바람으로 연속해서 탈수된다. 시험재료는 2020년 6월 수확된 전남 순천 매실로 옥영 L, 남고 L 및 2L이었다. 세척 시험은 옥 영을 공급량별 3수준(10, 20, 30kg)로 세척 전후 탁도를 비교하였다. 세척 및 탈수 시험은 남고 L, 2L에 대해 세척과 탈수를 연속으로 하면서 세척 전후 탁도, 세척한 매실의 탈수율, 작업시간을 측정하였다. 탁도는 세척 전후 매실 300g를 증류수 500ml로 3분 동안 세척 후, 600rpm 30초 동안 진탕하여 10ml씩 수질측정기(90-FLT, TPS, USA)로 측 정하였다. 세척수 온도변화를 측정하였으며, 매실에 손상 여부를 살펴보았다. 모든 시험은 3반복하여 평균값으로 나 타내었다. 시험결과, 옥영의 세척 전 탁도(ppm)는 공급량별로 각각 9.6, 11.8 및 12.3이었으나 세척 후 탁도는 각각 4.5, 4.2 및 5.5으로 세척 정도를 수치로 확인할 수 있었다. 남고 L 및 2L의 세척 및 탈수 시험결과 탁도(ppm)는 세 척 전 13.5, 23.4이었으나 세척 후 8.0, 12.0으로 낮아졌다. 옥영에 비해 남고의 탁도가 높았는데 이는 한여름에 수 확되어 시험 기간 동안 일부가 물러진 남고의 과즙 때문인 것으로 보인다. 탈수 시험결과 세척 시 매실에 묻은 물 기의 31.2%, 38.2%를 제거하는 것으로 나타났다. 손상 매실은 없었으며, 시험에 걸린 시간(초)은 900.3~912.0이었다. 세척수 온도는 0.5℃가 상승하여 매실에는 영향이 없을 것으로 판단되었다. 본 연구로 매실의 세척 및 탈수 정도를 수치로 볼 수 있었다. 그러나 세척 전후 품질 등의 분석, 30% 남짓한 탈수율을 높이기 위한 연구가 필요하다. 이를 바탕으로 세척부터 포장까지 매실 절임가공 생산 전과정 기계화 연구로 이어가야 할 것이다.

In this study, air scouring cleaning was selected and applied among 5 small blocks (S1~S5) in domestic S cities to analyze the cleaning effect of particles causing discoloration. In order to identify the cleaning effect, 10 locations were selected as water quality investigation point, such as the stagnant or water mains ends. Removal of solids, variation of particle components, weight and concentration were analyzed. And the level of the cleanness of the surface inside water mains using endoscope was investigated. As a result of analysis, the solids discharged after cleaning were mainly sand and gravel, pieces related to pipe materials, and corrosion products. As a result of analyzing the concentrated particles of the filter before and after cleaning, it was found that the change in discoloration on the filter was large. In addition, as a result of comparing the weight and the concentration of the particles, it was found that the particles causing discoloration were significantly removed after cleaning. From the results of the endoscopy, it was confirmed that most of the precipitated and accumulated dark yellow discoloration matters inside water mains were removed through cleaning. Therefore, it seems that the particles causing discoloration in water decreased after cleaning. Therefore, it is expected that, if properly cleaning was applied, matters that cause discoloration can be removed from the water mains, and customer's complaints can also be reduced through water quality improvement.

In this paper, internal and external flow analysis of nozzle for a automatic bike washing machine was performed using Ansys Fluent, by varying nozzle injection pressure and angle. The pressure and velocity distributions generated at the nozzle outlet from internal flow analysis were applied for inlet condition of the external flow analysis of the nozzle. As a criterion for the cleaning efficiency, the shear stress condition provided by EHEDG[5] was used and an area of shear stress of 3 Pa or more according to the spray angle and pressure was compared. It is expected that the results of this paper will be applied to the development of automatic contactless bike washing nozzle.

본 연구는 (주)퓨어엔비텍에서 제조한 multi-bore 형태의 중공사 막을 이용하여 오염된 원수의 투과 후 오염된 막의 재사용을 위해 화학적 세정효율에 대해 파악하고자 하였으며 이를 위해 제조된 중공사 막의 재료는 내화학성이 좋은 PSf (polysulfone) 소재를 사용하였다. 실험은 소혈청 알부민(BSA)을 이용한 내오염성 평가 및 염기성 용액인 차아염소산나트륨 (NaOCl), 산성 용액인 구연산(citric acid)을 이용해 장기 함침하여 내화학성 평가를 진행하였다. 시간에 따른 수투과도와 인장강도를 측정하여 분리막의 기계적 강도와 성능의 감소에 대한 결과를 관찰하였다. 이후 소혈청 알부민으로 오염된 막의 화학적 용액에 따른 역세척 후 회복효율을 파악하였다. PSf 중공사 막은 뛰어난 내화학성을 가졌으며 화학적세척결과 차아염소 산나트륨의 효율이 높음을 확인하였다.