• Animal cells and systems
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• v.3 no.4
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• pp.407-412
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• 1999

The influence of eating habits and food type on the ultrastructural characteristics of the digestive tracts was studied under the scanning and transmission electron microscopes in two crustacean decapods (Hemigrapsus penicillatus De Haan; mud crab, Pinnotheres cyclinus Shen; symbiotic crab). The relative ratio of the length of midgut versus hindgut was 1:1 in the mud crab, but 4:1 in the symbiotic crab. Observation through the scanning electron microscope revealed that the midguts of both species have densely-arranged longitudinal mucosal folds with a smooth surface. In the hindgut of the mud crab, mucosal folds were longitudinally oriented, clusters of two to five spines were observed on the cuticular surface, and the length of the spine in the distal hindgut was longer than that in the proximal portion. In the symbiotic crab, the mucosal folds were irregulary arranged, and numerous rudimentary spinal structures were noted on the cuticular surface. Through observation of a transmission electron microscope, the epithelial cells of the midgut in both species had numerous microvilli, but the length of the microvilli was slightly longer in the mud crab than in the symbiotic crab. The central layer of the basement membrane and the muscular layer of the midgut were more developed in the mud crab than in the symbiotic crab. The thickness of the cuticular layer over the hindgut surface in the mud crab was about 4 times than that of the symbiotic crab.

• Journal of Environmental Science International
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• v.12 no.4
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• pp.469-476
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• 2003

In order to examine the pre-treatment effect of crab shell en Pb$^{2+}$ removal by crab shell in aqueous solution, acid and alkali pre-treated crab shell were used. Electron microscopy techniques such as TEM (transmission electron microscopy) and SEM (scanning electron microscopy), and EDX (energy dispersive X-ray) and FTIR (Fourier transform infrared) spectrometry techniques were used to investigate the process of Pb$^{2+}$ removal by acid and alkali pre-treated crab shell. The Pb$^{2+}$ removal by acid pre-treated crab shell was much lower than that by untreated crab shell because of the decrease of CaCO$_3$ from the crab shell. However, the Pb$^{2+}$removal by alkali pre-treated crab shell increased compared to that by untreated crab shell. The results were confirmed by TEM, SEM, EDX and FTIR.nd FTIR.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.3
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• pp.137-142
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• 2005

New types of patties were prepared with surimi and crab paste, and then characterized. With an increase of additional ratios of crab paste, the moisture (64.8 to $61.5\%$) of the patties slightly decreased while the ash contents (2.3 to $3.7\%$) increased. The Hunter's color values of the patties decreased in lightness (L value, 58.79 to 54.27) but increased in redness (a value, -2.77 to 3.54). Thus, the patties that had added crab paste appeared slightly more reddish. According to the increasing of additional ratios of crab paste, sensory scores on color and flavor increased whereas the texture score decreased. From the above results, based on physical properties and sensory evaluation, the desirable additional ratio of crab paste for preparing patty was $15\%$. The calcium and phosphorus contents of the patties with the addition of $15\%$ crab paste were 148.8 mg/100 g and 139.6 mg/100 g, respectively, and their ratio (approximately 1:1) was the optimal range in body absorption efficiency. The calcium absorption rate with the $15\%$ additions was 4.9 times higher than that of the patty with no additions. Total amino acid content (16,302 mg/100 g) of the $15\%$ additions showed no difference to the patty without additions, and the major amino acids were aspartic acid, glutamic acid, leucine and lysine. Exceptionally, the cysteine content of the patty with the $15\%$ crab paste additions was 2 times higher than that found in the patty without crab paste. The major fatty acids were 16:0, 18:1n-9 and 18:2n-6 of the total lipids, and there was no difference between the patties with and without crab paste. The above results showed that crab paste can be used as a crab surimi gel source.

• Journal of Environmental Science International
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• v.11 no.4
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• pp.361-366
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• 2002

Several effects on Pb$^{2+}$ removal by crab shell from aqueous solution were investigated. As the increase of initial Pb$^{2+}$ concentration and decrease of initial crab shell concentration, the time required to reach an equilibrium state and the residual Pb$^{2+}$ concentration increased. In our experimental ranges, the optimum initial Pb$^{2+}$ concentration and crab shell concentration were below 103 mg/$\ell$ and over 0.5 mg/$\ell$, respectively. Also, in order to investigate the mechanism of Pb$^{2+}$ removal by crab shell in aqueous solution, the crab shell was compared with chitosan and chitin on aspects of Pb$^{2+}$ removal capacity and Pb$^{2+}$ removal rate. The Pb$^{2+}$ removal by crab shell was greater than that by chitin and chitosan. The role of chitin was not so great in Pb$^{2+}$ removal by crab shell. The Pb$^{2+}$ removal by chitosan was not exactly correlated to the molecular weight of chitosan. weight of chitosan.

• Development and Reproduction
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• v.25 no.3
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• pp.185-192
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• 2021

The five oligonucleotide primers (oligo-primers) turned out a total of 335 fragments (FMs) (52.9%) in the blue crab (Portunus trituberculatus) group alpha and 298 FMs (47.1%) in the crab group beta, with the FM scales range varying from 100 bp to 2,000 bp. The highest band-sharing (BS) value (0.907) was found between individual's no. 19 and no. 20 within the blue crab group beta. Parties in the blue crab group beta (0.601±0.017) had higher BS rates than did parties from the crab group alpha (0.563±0.017) (p<0.05). The polar dendrogram got by the five oligo-primers points out two genetic extents: bundle I (BLUECRAB 01, 03, 04, 05, 06, 08, and 10) and bundle II (BLUECRAB 02, 07, 09. 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, and 22). The OPD-01 primer revealed 22 loci shared by all the examples of the as FMs of 1,000 bp. The oligo-primer OPA-05 made unique loci shared to each group (ULSEG), almost 400 bp and 500 bp, individually, in blue crab group beta. The remaining oligo-primers did not reveal any loci shared by the two crab groups (LSTG). The average number of ULSEG was diverse and 1.6-fold higher in the crab group beta than in the crab group alpha.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.281-288
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• 2002

Crab shell 충진 칼럼을 이용한 수중 중금속의 연속적 제거에 있어서 다른 흡착제 (CER, GAC, Zeolite)와 비교 실험을 통하여 crab shell의 중금속 제거능을 알아보았다. 수중 $Pb^2+/{2+}$ 의 column을 이용한 연속적제거에 있어서 미세침전부분이 외부로 배출됨으로 칼럼 외부에 여과시스템의 도입함으로써 중금속 제거능을 높일 수 있을 것으로 판단된다. 중금속의 연속적 제거에 있어서 CER의 1,000 BVs까지의 전체 제거량은 0.35mmol/g, GAC는 0.17mmo1/g, zeolite는 0.16 mmol/g으로 나타났고 crab shell에 의한 중금속 제거량은 0.61 mmol/g으로 다른 흡착제보다 높은 제거효율을 보였다. 수중 중금속의 연속적 제거에 있어서 여러 흡착제의 제거 순서는 crab shell > CER > GAC > zeolite 로 나타났다. Crab shell의 경우는 파과점이 2,000 BVs에서 나타나므로 일반적인 폐수처리의 화학적 처리 후 잔존하는 저농도의 중금속을 제거를 위해 crab shell 충진 칼럼이 유용 할 것으로 판단된다. Crab shell의 재사용 가능성을 알아보기 위하여 crab shell을 이용한 중금속 제거공정에서 연속적인 중금속제거와 탈착과정을 통하여 보았을 때 1회에서 $Pb^2+/{2+}$제거된 량은 0.71 mmol/g 제거되었고 2회에서는 0.27 mmol/g, 3회에서는 0.02 mmol/g으로 급격하게 crab shell의 제거능이 떨어지는 것을 관찰 할 수 있다. 이는 crab shell이 재사용이 불가능 할 것으로 판단되나 다른 흡착제보다 월등한 제거효율을 보이므로 수중 중금속의 연속적 제거 흡착제 적합할 것으로 판단된다.

• Journal of the Korean Dietetic Association
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• v.20 no.4
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• pp.306-319
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• 2014

This study is basic research focused on product development and market activation based on analysis of current usage and demand for development of processed blue crabs. A total of 556 subjects aged 20s to 60s living in the Seoul area were surveyed. According to the survey, 65.1% of subjects consumed blue crabs at home, and 82% of them purchased blue crabs whole and undressed. Respondents gave higher marks to taste, nutrition, and texture compared to ingredient preparation, eating method, and price. Majority of blue crab consumers had no experiences of consuming processed blue crabs. Exactly 57.0% of consumers purchased them at big shopping centers, and the reason for purchasing was their good taste. When female consumers purchased processed blue crabs, they checked every part carefully compared to male consumers. Women gave high scores to blue crab powder, blue crab extract, blue crab croquette, and blue crab cake compared to men, demonstrating the necessity of developing processed blue crabs. Furthermore, the experienced processed blue crab group recognized the necessity of developing processed blue crabs compared to the inexperienced group. People showed significant differences in purchasing processed blue crabs according to gender as well as previous experience of blue crab consumption.

• Journal of Wellbeing Management and Applied Psychology
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• v.5 no.1
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• pp.9-22
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• 2022

Purpose: The purpose of this study is to develop a kimchi recipe for immunity enhancement using snow crab, which has high food value in the era of COVID-19. Research design, data and methodology: The snow crab kimchi manufacturing method of this study includes the steps of preparing a kimchi seasoning containing snow crab seasoning and chitosan powder. Kimchi seasoning is made by adding 5 parts by weight of crab seasoning and 1 part by weight of chitosan powder to 100 parts by weight of the basic kimchi seasoning prepared by mixing radish, minced garlic, minced ginger, onion juice, anchovy sauce, red pepper powder and glutinous rice paste. Results: It was possible to develop new flavors, possibilities and characteristics of snow crab kimchi by extending the health and functional effects, taste, and preservation period without significantly changing the unique manufacturing method, taste and function of kimchi, including snow crab. Conclusions: Snow crab kimchi was excellent in taste and aroma while enhancing the health functions of the body, such as improving people's immunity. The developed snow crab kimchi manufacturing method can not only improve people's health, but also expand the choice of preference for kimchi taste and shelf life.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.3
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• pp.131-140
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• 2005

Fault-tolerant gait generation of a hexapod robot with crab walking is proposed. The considered fault is a locked joint failure, which prevents a joint of a leg from moving and makes it locked in a known position. Due to the reduced workspace of a failed leg, fault-tolerant crab walking has a limitation in the range of heading direction. In this paper, an accessible range of the crab angle is derived for a given configuration of the failed leg and, based on the principles of fault-tolerant gait planning, periodic crab gaits are proposed in which a hexapod robot realizes crab walking after a locked joint failure, having a reasonable stride length and stability margin. The proposed crab walking is then applied to path planning on uneven terrain with positive obstacles. i.e., protruded obstacles which legged robots cannot cross over but have to take a roundabout route to avoid. The robot trajectory should be generated such that the crab angle does not exceed the restricted range caused by a locked joint failure.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.2
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• pp.93-108
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• 1990

Complete larval development Orithyia sinica (Linnaeus) is composed of three zoeal ins-tars and megalopa. Survival of instals was higher in $20^{\circ}C$ than in ambient temperature. Intermolt period generally increased with the increase of number of instals, but a notable decrease was observed from Crab-5 to prepuerty molt instals(Crab-7). Zoeas and me-galopa reared at higher temperature regime were samller than those reared at lower temperature. No temperature effect was shown in the size of crab instals. Growth factors fluctuate with the increase of number of instals, but there was an overall trend of net decrease. Growth factor was $35.65\~41.4\%$ for zoeal instals, and they were $18.00\~30.91\%$ for crab instals.