• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.114-118
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• 1997

Effect of water temperature, salt and $MgCl_2$ concentration on sand ejection characteristics of short neck clam, Luditapes philippinarum was investigated. Unlike other shell fish such as red shell, arkshell and surf clam, treatment of short neck clam with sea water was evaluated not effective as sand ejection conditions. Sand ejection activity of short neck clam was shown effective at $2.5\%$ NaCl (pH 8.0) at $25^{\circ}C$. This activity was enhanced about 1.57 times when 50 mM $MgCl_2$ were added to the above mentioned conditions. But the extent of sand ejection activity was shown higher in the order of sea water $(3.2\%\;salt)+20mM\;MgCl_2$, sea water $(3.2\%\;salt),\;2.5\%\;NaCl+50mM\;MgCl_2$, treatments. Therefore, it was suggested that habitat conditions and Mg ions could be responsible for biological activity and concominant sand ejection of short neck clam.

• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.208-218
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• 2001

We have investigated the gonad index (GI), gonadal development, reproductive cycle, first sexual maturity, sex ratio, the number of spawned eggs and spawning frequency of the Manila clam, Ruditapes philippinarum. Samples were collected from the intertidal zone of Komso Bay, Korea from January to December in 1999. Monthly changes in the gonad index (GI) and condition index showed a similar pattern in the reproductive cycle. The spawning period was once a year between early June and early October, there was a spawning peak between July and August when seawater temperature was over $20^{\circ}C$. The reproductive cycle of this species can be categorized into five successive stages; early active (February to March), late active (April to May), ripe (April to August), partially spawned (June to October), and spent/inactive stage (August to March). Percentages of first sexual maturity of female and male clams of l5.1-20.0mm in shell length were $56.3\%$ and $60.0\%$, respectively, and $100\%$ for the clams >25. mm. The sex ratio of individuals >15.1 mm in shell length was about 1:1 $(\chi^2= 0.02,\;p>0.05)$. Number of the eggs released from each clam by the induction increased as the size of clam in terms of shell length increased. Mean number of the eggs from the second induction of the spawning was $75.35-84.30\%$ $(average\;79.81\%)$ of the number of the eggs released in the first spawning. Our data indicated that R. philippinarum in Komso Bay has one major spawning peak with over two minor spawning, and the interval of each spawning was estimated to be approximately 15-17 (average 16.5) days.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.842-848
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• 2009

The purpose of this study was to determine the extent of domoic acid (DA) a potent neurotoxin, responsible for the syndrome amnesic shellfish poisoning (ASP) contamination of various species of bivalve shellfish purchased from fish market in Korea and the implications for food safety. Liquid chromatography (LC) methods were applied to quantify DA in shellfish after sample clean-up using solid-phase extraction (SPE) with strong anion exchange (SAX) cartridges. Toxin detection was achieved using photodiode array ultraviolet (LC-UV) and electrospray ionization-mass (LC-ESI-MS). DA was identified in 4 bivalve shellfishes of 872 shellfishes collected from March, 2006 to October, 2007 in Korea. DA amount of 3 surf clams (Mactra veneriformis) collected at Seoul, Daejeon, and Daegu were 4.13, 1.99, and 1.94 mg/kg, respectively. DA amount of 1 pink butterfly shell (Peronidia venulosa) collected at Seoul was 3.02 mg DA/kg. The amounts of DA that were present in 4 bivalve shellfishes were within EU guideline limits for sale of shellfish (20 mg DA/kg).

• Journal of architectural history
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• v.15 no.5
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• pp.7-18
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• 2006

A lot of relics were unearthed in the Shinchang-dong wetland site, which can help restore prehistoric life style, including construction tools such as wood doors, wood hammers, ax handgrips, sickle handgrips, wedges, awls, wood pillars and connection members, food vessels made of earth or wood and fish, shell fish, seeds and remains of weapons. In particular, a door was found in the site, which was measured at 110cm long and 37cm wide. If restored it will be 75cm wide. The door seems to date back as far as the 1st century B. C., which would be the oldest one ever discovered in Korea. This paper is intended to explore the implications of the door by investigating the environment of the Shinchang-dong wetland site bearing the relics intact, manufacturing techniques and times of manufacturing of the door as well as attributes of doors presented in the literature related to old time architecture such as Goguryeo tomb paintings and house-shaped vessels. It also intends to provide basic data for study of residential architecture in prehistoric times.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.747-754
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• 1999

Food waste in school foodservices is an important factors in managing expense and in evaluating the acceptance of served meals. This study was undertaken to investigate the management of food waste and the opinion of dietitians in one hundred fourty nine elementary school foodservices, in Pusan, Korea. When serving places were compared, the classroom generated more leftover and plate waste than those of lunchroom(p<0.05). In rank for generating raw waste, the residue from vegetables was the highest in first order. Fruit, eggs, fish, and shell fish also left the most raw waste, respectively, in descending order. The residue that generated the most plate waste in the first and the second order was from soup and pot stew, and vegatables side dishes, respectively. The treatment process of food waste which was the most common in school foodservices was the fertilization by processing machine in order to make recyclable fertilizer(52.1%). Food waste at 30.8% of foodservices was processed for live stock feed. At 92.3% of investigated foodservices, food waste water was drained through a round net basket. Before treating as a waste, food residue was recycled at only 41.9% of foodservices. The main utilization of food residue was the production of soap from used oil. Most dietitians in school foodservices recognized that treating food waste was not so inconvenient, although, the problems of odor and hygiene were not solved. They also thought that the liquid residue(54.1%) and oil(30.4%) among food waste were primarily responsible for resulting environmental pollution.

• Economic and Environmental Geology
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• v.38 no.2 s.171
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• pp.129-134
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• 2005

The $^{87}Sr/^{86}Sr$ ratios between water and biogenic material are similar in marine and lacustrine environment. Pb isotope ratios we, however, reported not to have been corresponding between the biological tissues and ambient water in aquatic system, contrary to the Sr isotope ratios. In order to explore the potential application of two isotopes as environmental tracers, we report here the isotopic compositions of strontium and lead of gastropod shell in fresh water in Jinan area. The $^{87}Sr/^{86}Sr$ ratios of carbonate shells of gastropod living in fresh stream water, are similar as that of ambient water but are different by sites. The different $^{87}Sr/^{86}Sr$ ratios of stream water between the sites is likely caused by the difference of the isotopic composition of Sr derived form rocks in the basin. In contrast, there is a distinct difference of the lead isotopic values between the water and the gastropod shell, suggesting that shell-fish available lead in aquatic system is different from dissolved lead in water. It is assumed that the majority of Pb in stream water is derived from atmospheric Pb accumulated on soil materials over years rather than from rock.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.2
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• pp.80-84
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• 1988

The change of cell counts of Vibrio vulnificus in meat homogenates of fish and shellfish by the storage time and temperature was examined to get basic information for precautionary steps against septicemia from slices of raw fish (sashimi). Therefore, we inoculated raw and cooked meat homogenates of fish and shellfish with Vibrio vulificus M-8 (isolated from shellfish ) and stored them at $-20^{\circ}C,\;4^{\circ}C\;and\;30^{\circ}C$ for 72 hours. Vibrio vulnificus M-8 was not detected in 32 hours when it was frozen and stored at $-20^{\circ}C$ after inoculating them into phosphate buffer solution at concentration of $10^5\;cell/ml$, while the existance of Vibrio vulnificus was identified after 72 hours of storage at the same temperature in case of inoculation into the meat homogenate of yellow tail. The cell count of Vibrio vulnificus was decreased as about $20\%$ of initial count after 2 hours storage at $4^{\circ}C$ in phosphate buffer solution with fish and shellfish homgenates. From the experimental results it was recognized that Vibrio vulnificus was labile to the cold stress. In comparison to the growth of growth of Vibrio M-8 at $30^{\circ}C$ in the raw and cooked meat of the yellow tail(Seriola guingueradita), snapper(Chrysophrys major), ark shell(Anadra brouhgtonii), and oyster(Crassostrea gigas), the raw meat homogenates were more excellent than the cooked ones though all fish and shellfish meat homogenates were proves to be good for the growth of the microbe.

• Journal of the Korean Ceramic Society
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• v.55 no.6
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• pp.570-575
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• 2018

Hydroxyapatites (HAps) were synthesized using the powdered waste of fishery products, i.e., fish scales and crab shells, as starting materials. HAp was synthesized by a wet-chemistry method followed by calcination at 600 and $800^{\circ}C$. Calcined crabshell powder revealed a single HAp phase and fine powder, while calcined fish-scale powder showed a ${\beta}-TCP$ secondary phase, even at the higher calcination temperature. Dense HAp pellets were obtained from the crab-shell powder by spark plasma sintering at $1000^{\circ}C$ for 10 min under applied pressures of 40 and 80 MPa in a vacuum state, giving sample densities of 2.93 and $3.06g/cm^3$, respectively. The estimated grain size of HAp was $448{\pm}96$ and $283{\pm}59nm$ for applied pressures of 40 and 80 MPa, respectively. In contrast, the HAp obtained using the pressureless sintering technique showed excessive grain growth without further densification.

• Korean journal of food and cookery science
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• v.28 no.6
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• pp.829-837
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• 2012

This study was investigated seafoods provided by school food service and students' preferences for and perceptions of seafoods. The subjects were 275 second grade(age 14-16) students of 4 middle schools in Gyeongnam. The results were as follows. The most main seafoods intake place was 'home'(65.8%). 'School food service' took meaningful ratio(20.7%) of students' seafoods intakes. In the intake amount of seafoods provided by school food service, 'all' took 22.5%(male 31.6%, female 14.1%), 'more than provided' took 1.5%(male 3.0%, female 0%). Male students ate seafoods more than female students did(p<.001). In seafoods providing frequency, '2~3 times a week' took 74.5%, '4~5 times a week' took higher ratio in males' schools, while '0~1 times a week' took higher ratio in females'(p<.05). In perceptions of seafoods, most subjects had positive perceptions as 'good for health'(3.95), 'various kinds'(3.75) except 'good peculiar smell' got smallest point(2.85). In means of learning about seafoods names, 'by looking at everyday menu' took 64.6%. In taking nutrition education, 'no nutrition education' took 69.5%. In preferences for seafoods using 5-point scale, males' preferences were higher than females'(p<.001). 48.1% of males got higher than 4 point, while 14.1% of females did. In improvement measures of seafoods, 'provide various kinds'(47.3%) took highest ratio. In preferences for seafoods by seafoods kinds, preference for 'crustacean' was highest while preferences for 'shell fish' and 'fish' were relatively low. Both male and female students highly preferred laver, shrimp, swimming crab, small octopus, fish cake and tuna canned goods. Male students' preferences were higher than female students' for most kinds of seafoods. In preferences for seafoods by cooking methods, preferences for 'grilled', 'stir fried', 'pan fried' were relatively high, 'braised', 'deep fried', 'steamed' were relatively low. Males' preferences were higher than females' for every cooking method except 'steamed'.

• Korean Journal of Community Nutrition
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• v.8 no.5
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• pp.699-707
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• 2003

This study examined the effectiveness of two commonly used dietary assessment methods (the 24-hour recall and the food frequency questionnaire) in the epidemiological investigations of health-related habits and degenerative diseases. This cross sectional project in the Seoul area was conducted for the purpose of establishing cohort subjects and collecting reliable nutrient intake data for a further large-scale cross sectional study. The subjects were 91 volunteers from the Seoul area with a mean age of 53.5 \pm 9.6 for the males and 52.2 \pm 8.9 for the females. The subjects had a relatively high educational background, were from high socioeconomic levels, and were greatly concerned about healthrelated life styles. There was a significantly negative correlation between their smoking and their nutrient intake. Their drinking habits, their self-estimated health status and their concern or stress about being healthy did not have any influence on their nutrient intakes. Skipping meals was the most undesirable dietary habit influencing their nutrient intakes, and the next was their irregularity of eating meals. The subjects who liked legumes and fish had higher intakes of iron and niacin and those who liked milk and dairy products had higher intakes of calcium, vitamin \B_2 and fat. The subjects who considered themselves not to be healthy consumed higher amounts of fish and shell-fish, and those who considered themselves to be healthy consumed higher amounts of vegetables. The smokers consumed less fruits than non-smokers, but there was no correlation between their drinking and consumption of the food groups. There was no correlation between their food consumption frequency and their skipping meals or meal irregularity. There were positive correlations between their food likes and food consumption frequency for foods such as meat, milk and dairy products, seaweeds and fruits. Therefore, their smoking, skipping meals and meal irregularity appeared to greatly influence their nutrient intakes. Significant correlations were found between their health-related habits and their food group preferences and food frequencies. This implies that simple surveying methods using criteria such as smoking, skipping meals and meal irregularity, food group preferences and eating frequencies can be used as useful tools in the assessment of nutritional statuses.