이온교환막은 전하를 띤 작용기를 통해 특정 이온을 선택적으로 투과시키는 분리막으로, 전기투석, 역전기투석, 바이폴라막 전기투석 등 다양한 전기화학 공정에서 핵심 소재로 활용되고 있다. 최근 음이온교환막(anion-exchange membrane, AEM) 연구는 단순한 전하 선택성을 넘어 양성자 차단 AEM과 1가 이온 선택성 AEM과 같이 특정 이온에 대한 선택 적 투과를 제어하는 방향으로 발전하고 있다. 양성자 차단 AEM은 폐산 회수 및 산/염기 재생 공정에서 양성자 누출에 의한 효율 저하 문제를 해결하기 위한 핵심 소재로 주목받고 있으며, 1가 이온 선택성 AEM은 해수 담수화 및 자원 회수 과정에서 2가 음이온을 효과적으로 차단하기 위해 연구되고 있다. 본 총설에서는 이러한 기능성 AEM의 구조적 설계, 이온 수송 메커 니즘, 주요 성능 인자 및 최신 연구 동향에 대해 소개하고자 한다.

This study assessed the effects of mesh-size variation on the size-selective performance and operational characteristics of tie-down gillnets targeting the blackedged sculpin (Gymnocanthus herzensteini) in the East Sea. Four mesh sizes (84, 90, 105, and 120 mm) were evaluated under standardized field conditions, and length-frequency data were analyzed using the SELECT model in conjunction with two relative performance metrics, the catch comparison rate (CCR) and catch ratio (CR). Larger meshes produced selectivity curves shifted toward greater body lengths, and the deformation of the net panels induced by the tie-down structure led to distinctly broad selection ranges. These patterns indicate that retention probability is influenced by both the geometric mesh – body relationship and the mechanical distortion of the netting. Relative efficiency analyses confirmed the superior performance of larger meshes for capturing larger individuals although overall catch declined as mesh size increased. The results clarify the selective properties inherent to tie-down gillnets and provide scientifically grounded information that may support the development of mesh-size regulations, bycatch mitigation approaches, and resource management strategies for coastal gillnet fisheries.

This study analyzed the selectivity of cylindrical net pot for the swimming crab (Charybdis japonica) using the SELECT model with a normal function. Data were obtained from four sea trials employing six mesh sizes (20.2, 27.6, 33.7, 37.9, 50.5, and 65.0 mm). The carapace length corresponding to the maximum catch in each mesh size ranged from 32.6 to 36.7 mm, whereas larger meshes of 50.5 mm and 65.0 mm exhibited peaks at 50.3 - 52.3 mm. This result clearly demonstrated that the size composition of the catch varied with increasing mesh size. The 50% retention carapace length (L50) ranged from 25.2 to 47.8 mm. When comparing fishing performance, smaller mesh pots generally yielded higher catches relative to the 20.2 mm reference pot. A comparison between the legal mesh size of 33.7 mm (nominal 35 mm) and the adjacent 37.9 mm mesh revealed that a 4 mm increase in mesh size significantly raised the proportion of crabs larger than 38 mm carapace length. Based on the minimum size at first maturity (28.86 mm), the optimal mesh size of the pot was estimated to be 35.59 mm. However, more precise sea trials and analyses are required to obtain reliable results. The findings also indicate that changes in mesh size have a clear influence on the size composition of swimming crab catches, suggesting that the correlation between mesh size and catch characteristics must be carefully considered to ensure sustainable resource management.

This study evaluated catch selectivity differences between sea pike (Sphyraena japonica) and Spanish mackerel (Scomberomorus niphonius) using a modified codend with square mesh side panels in bottom trawl. Sea trials were conducted with the covered codend technique widely used to estimate codend selectivity curves at the coastal sea of Yokji-do, Gyeongsangnam-do, from December 2024 to January 2025. Selectivity curves were fitted using a B-spline model for sea pike and a probit model for spanish mackerel. The estimated 50% retention lengths ( ) were 26.88 cm for sea pike and 42.92 cm for Spanish mackerel, with selection ranges () of 2.42 cm and 10.76 cm, respectively. Spanish mackerel was shown the broader and more gradual selectivity curve, while sea pike showed steeper selectivity. This study found that selectivity changes depending on the change in the net structure of the trawl tip. In addition, a difference in selectivity was observed for two species with different morphological characteristics.

In this paper, the commercial anion exchange resin (IRA900) was used to investigate the adsorption properties, comparing the anion selectivity of phosphate and sulfate in water. The phosphate removal efficiency was 29.6% less than sulfate in single condition, and significantly decreased from 44.8% to 3.47 in mixed conditions while sulfate removal efficiency remained unchanged, confirming a higher selectivity for sulfate over phosphate. In the pH effect, phosphate removal efficiency increased with increase of pH due to the increased HPO4 2- species. The total removal efficiency of phosphate and sulfate was obtained approximately 62% in mixed condition, regardless of solution pH, indicating that the total anion exchange capacity was not influenced in the pH. The values of qmL and bL derived from Langmuir isotherm equation were 11.5 and 8.10 times higher for sulfate than for phosphate in mixed conditions. In single condition, sulfate and phosphate reached to equilibrium at 6 and 3 h, respectively. In mixed condition, phosphate was desorbed by the sulfate after 1h and the time to equilibrium for sulfate was retarded to 6h. Furthermore, when comparing the separation factor (αP/S), increasing the initial concentration led to higher selectivity of phosphate.

This study aimed to investigate the catch selectivity characteristics related to the mesh arrangement of the codend in bottom trawl. Sea trials were conducted using the covered codend method from January 16 to 17, 2024, off the southern coast of Gyeongsangnam-do, focusing on the side panels of diamond and square mesh codend. A probit model was used in the selectivity analysis to estimate retention probability curves for sea pike comparing the  , , and  selectivity lengths, the selection range ( ), and the corresponding  and  values. The estimated 50% selection lengths were 23.82 cm for the diamond mesh and 25.20 cm for the square mesh whereas the corresponding selection ranges were 5.23 cm for the diamond mesh and 3.71 cm for the square mesh. The  and  values for the square mesh were lower, at 35.91 and 36.71, respectively, compared to 37.65 and 38.45 for the diamond mesh. Additionally, the retention probability at a fork length of 15 cm was lower for the square mesh than for the diamond mesh. These findings provide practical insights for gear design while contributing to the reduction of bycatch and small size fish catches in bottom trawl.

This study analyzed the selectivity of Octopus minor using the extended SELECT model in netpots. The data used for the analysis were collected from ten sea trials conducted between 2009 and 2010 using cylindrical octopus traps with six mesh sizes (16, 18, 20, 22, 24, and 26 mm). The selectivity analysis was performed using two models: the p-fixed split model and the p-estimated split model, depending on whether the encounter probability (split parameter) was estimated. The model fit was evaluated by comparing the model deviation and AIC values. The results showed that octopus catch decreased as mesh size increased, with a general tendency for larger individuals to be caught. The 16 mm trap, which had the smallest mesh size, accounted for 25.9% of the total octopus catch by number of individuals while the 22 mm trap, a commercial mesh size, accounted for 14.1%. The CPUE based on weight was highest for the 18 mm trap. The selectivity analysis results indicated that the p-estimated split model provided the best fit, and the 50% selection length for the 22 mm trap was 64.57 mm. In this study, reliability of various models was considered in the mesh selectivity analysis, and the findings are intended to serve as basic data for improving relevant regulations and deriving scientific research results.

In this study, the refinement of Multiwalled Carbon Nanotubes (MWCNTs) derived from chemical vapor decomposition is investigated. An ultrasonic pretreatment method is employed to disentangle carbon and metal impurities intertwined with MWCNTs. The pretreated MWCNTs exhibit a marginal decrease in C–O/C = O content from 8.9 to 8.8%, accompanied by a 2.5% increase in sp3 carbon content, indicating a mildly destructive pretreatment approach. Subsequently, selective oxidation by CO2 and hydrochloric acid etching are utilized to selectively remove carbon impurities and residual metal, respectively. The resulting yield of intact MWCNTs is approximately 85.65 wt.%, signifying a 19.91% enhancement in the one-way yield of pristine MWCNTs. Notably, the residual metal content experiences a substantial reduction from 9.95 ± 2.42 wt.% to 1.34 ± 0.06 wt.%, representing a 15.68% increase in the removal rate. These compelling findings highlight the potential of employing a mild purification process for MWCNTs production, demonstrating promising application prospects.

고성능 분리막 제조기술과 더불어 새로운 분리막 다단공정 설계를 통해 용매사용량 감소 및 선택도 향상이 가능 하다. 본 연구에서는 내용매성 셀룰로스 나노분리막을 제조하여 용매에 따른 용질의 선택도 차이를 비교하였다. 제막한 셀룰 로스 막을 기반으로 비극성 용매의 선택도 평가를 진행하였으며, 비극성 용매에서 용질에 대한 음배제율이 관측되었다. 특히, 분자량이 클수록 음배제율이 높아지는 역선택도의 거동을 확인하였다. 이를 기반으로 설계한 공정에서는 기존 분획 공정 대 비 3배 이상의 용매저감이 가능한 것을 확인할 수 있었다.

This study quantitatively evaluated size selectivity for three netting shapes (T0; regular, T45, T90) and hanging ratio (35%, 70%) of T0 netting used for trawl codend. The size selectivity experiment was performed in a tank using a cube experimental model with a length of 50 cm on one side and 389 experimental individuals, jack mackerel (Trachurus japonicus). In the selectivity analysis, a selectivity curve was created based on the selection ratio using a logistic function, and the 25%, 50%, and 70% selection length and selection range  were obtained. The T0 netting was 19.54 cm when the 50% selective length, which is a selectivity evaluation index, had a hanging ratio of 35%, a selection range of 0.51 cm, and 22.70 cm and 3.08 cm for the hanging ratio of 70%. The T45 netting was 24.34 cm and 2.13 cm, and the T90 netting was 23.51 cm and 2.84 cm. The results of the T45 netting and the T90 netting are similar, and the 50% selection length and selection range were relatively larger than the T0 netting. There was a significant difference in the correlation between the circumference of the inner circle of the mesh by the shape of the netting and the body girth of the experimental individual (Pearson test,      ). There was no significant difference in the correlation between the selection ratio by the T0 netting, T45 netting, and T90 netting with a 70% hanging ratio (one-way ANOVA,   ). The results of this study showed that selectivity such as T45 netting and T90 netting appeared when the hanging ratio, which maximizes the area of T0 netting, was maintained at 70%.

In this study, a comparative test operation was conducted through the alternate haul method to examine the selectivity of the four mesh sizes (60 mm, 90 mm, 110 mm, and 130 mm) of the trawl codend. The selectivity was analyzed using the SELECT model considering the fishing efficiency (split parameter) of each fishing gear in the comparative test fishing operation in the trawl and the maximum likelihood method for parameter estimation. A selectivity master curve was estimated for several mesh sizes using the extended-SELECT model. As a result of analyzing the selectivity for silver croaker based on the results of three times hauls for each experimental gear, it was found that the size of the fish caught increased as the size of the mesh size increased. When the selectivity for each mesh size analyzed by the SELECT model considering the split ratio was evaluated based on the size of the AIC value, the estimated split model was superior to the equal split model. Based on the master curve, the 50% selection length value was 2.893, which was estimated to be 136 mm based on the mesh size of 60 mm. In some selectivity models, there was a large deviance between observed and theoretical values due to the non-uniformity of the distribution of fished length classes. As a result, it is considered that appropriate sea trials and selectivity evaluation methods with high reliability should be applied to present trawl fishery resource management methods.