• Particle and aerosol research
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• v.12 no.1
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• pp.11-20
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• 2016

A large amount of wear dust generated during train operation is a major dust source in urban railway tunnels. To check possibility of a louver dust collector for the removal of dust in the railway tunnel, five louver dust collector models were designed and their performance was tested in a wind tunnel. JIS Z 8901 Class 8 dust was used as a test dust. Pressure drop and particle collection efficiency were evaluated with the face velocity ranging from 1 m/s to 4 m/s. At this low velocity range, particle collection efficiency of the louver dust collector was found to be insensitive to air velocity and design parameters. Pressure drop was under 40 Pa, and $PM_{10}$ and $PM_{2.5}$ collection efficiencies were approximately 50% and 30%, respectively.

• Journal of Microbiology and Biotechnology
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• v.22 no.9
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• pp.1218-1223
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• 2012

${\varepsilon}$-Poly-$_L$-lysine (${\varepsilon}$-PL), produced by Streptomyces or Kitasatospora strains, is a homo-poly-amino acid of $_L$-lysine, which is used as a safe food preservative. The present study investigates the combined use of cell immobilization and in situ adsorption (ISA) to produce ${\varepsilon}$-PL in shaken flasks. Loofah sponge-immobilized Streptomyces ahygroscopicus GIM8 produced slightly more ${\varepsilon}$-PL than those immobilized on synthetic sponge, and sugarcane bagasse. Moreover, loofah sponge supported the maximum biomass. Hence, loofah sponge was chosen for cell immobilization. Meanwhile, the ion-exchange resin D152 was employed for ISA. The loofah sponge-immobilized cells produced $0.54{\pm}0.1g/l$ ${\varepsilon}$-PL, which significantly increased to $3.64{\pm}0.32g/l$ after combining with ISA through the addition of resin bags. The free cells with ISA using the dispersed resin yielded $2.73{\pm}0.26g/l$ of ${\varepsilon}$-PL, an increase from $0.82{\pm}0.08g/l$. These data illustrate that the proposed combination method improved production most significantly compared with either immobilization or ISA only. Moreover, the immobilized cells could be repeatedly used and an ${\varepsilon}$-PL total amount of $8.05{\pm}0.84g/l$ was obtained. The proposed combination method offers promising perspectives for ${\varepsilon}$-PL production.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.49-54
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• 2017

We collected and reared Theragra chalcogramma walleye pollock brood-stock for use in natural spawning tests and undertook to obtain domestic pollock via fertilized egg capture, development of fertilized eggs, and absorption of yolk sac after hatching. Whole pollock were caught with trammel and set nets and immediately placed in a deep-sea water tank. Adults were the most common pollock age group (43.0%; n = 86) among the 254 pollock captured in March 2014 with 57.9% (n = 147) being captured off Southern Gosung, Korea. The main spawning period of pollock is February (spawning phase of 91% of pollock). From the deep-sea tank, we collected 1640 mL of naturally fertilized eggs (~820,000 eggs) from 12 spawning events occurring between February 4 and 22 2015. The floating/ live eggs were maintained in deep-sea water tanks at $5.5{\pm}0.2^{\circ}C$. Egg size was $1.5{\pm}0.03mm$. Six hours after fertilization the eggs were at the 2 cell stage, and the eggs hatched approximately 340 hours after collection. At hatching, larval length and yolk sac area were $5.2{\pm}0.25mm$ and $9.5{\pm}1.00mm^2$ (100%), respectively. Four days after hatching, the yolk sac area was $2.2{\pm}0.53mm^2$ ($23.1{\pm}5.55%$). This is the first report of collection of naturally fertilized eggs from pollock and their subsequent hatching while held in an indoor deep-sea water tank. The results suggest that such collection could assist in the recovery of pollock resources and the possibility of domestic rearing of cultivated larvae.

• Korean Journal of Poultry Science
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• v.25 no.3
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• pp.113-118
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• 1998

These experiments were conducted to develope the artificial insemination methods of wild duct (Anas platyhychis platylyachos) . The characteristics of erect phallus and semen collected by the abdominal massage method were investigated in wild duck. The erection and withdrawal time of phallus were 50.70${\pm}$18.66 and 92.58${\pm}$51.95 sec. , respectively, in wild duck. The length, long and short diameter of erect phallus were 3.98${\pm}$0.49crn, 1.53${\pm}$0.15cm and 1.05${\pm}$0.04 cm, respectively, and the spiral grooves of erect phallus were 4 in wild duck. The volume of semen, concentration of spermatozoa and total sperm of an ejaculate were 0.18${\pm}$0.06 ml, 2.84${\pm}$0.03 x 10 9 /ml and 0.52${\pm}$0.21 x 10 cells, respectively, in wild duck. The motility of sperm and pH of semen were 49.06${\pm}$14. 35 and 7.6${\pm}$0.14 in wild duck.

• Journal of the Korean Chemical Society
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• v.26 no.1
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• pp.36-42
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• 1982

Filters were evaluated to use in the collection of ammonia and ammonium salts in the atmosphere. Ammonia from standard gas generator was collected on a glass fiber filter impregnated with a mixture of 3% boric acid and 25% glycerin. The collection efficiency by the impregnated filter was 96.4${\pm}$2.15% in pH control method and 97.4${\pm}$1.06% in the atmosphere for five measurements, respectively. Adsorption and desorption of gaseous ammonia were compared using three commercially available filters; glass fiber, quartz fiber and polycarbonate filters. Both glass and quartz fiber filters indicated some loss of ammonium salts and adsorption of ammonia, respectively. However, polycarbonate filter was found to be satisfactory for the collection of ammonium salts in the atmosphere. The minimum measurable concentration of ammonia was 0.83ppb (ca. 0.63${\mu}g$/$m^3$) by spectrophotometry of the indophenol method for the sample collected by 47mm${\phi}$ filter(20l/min, 60min). The sensitivity of the present method is about 20 folds higher than that of conventional method of bubbler collection followed by spectrophotometry, so that this method makes it possible to measure thevariation of ammoniacal concentrations in the atmosphere for a short time period of about 60 min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.829-836
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• 1995

This study was performed to evaluate the relationship between dietary, blood and urinary levels of lead and blood pressure and serum lipids in 30 healthy adult living in rural area of Korea. Analysis for the nutritional status of subjects were performed by 3-day dietary intake record, duplicated diet collection, 24-hour urine collection, and venous blood sampling before anthropometry. The mean daily intakes of lead estimated for 3 days was $120.1{\pm}22.0\mu\textrm{g}$. The blood levels and 24-hour urinary excretion of lead were $10.8{\pm}3.6\mu\textrm{g}/dl\;and\;36.5{\pm}9.5\mu\textrm{g}$, respectively. The systolic and diastolic blood pressure were $113.0{\pm}16.9mmHg\;and\;76.7{\pm}12.1\;mmHg$. The serum levels of total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol and ${\beta}-lipoprotein$ were $158.8{\pm}32.9mg/dl,\;104.6{\pm}48.8mg/dl,\;45.7{\pm}9.9mg/dl,\;92.2{\pm}28.5mg/dl\;and\;426.4{\pm}141.5mg/dl$, respectively. There was no significance in the relation between lead and blood pressure. In the relation between lead and serum lipids, it showed negative correlation with lead intake and HDL-choleterol at the level of significance of p<0.01. But there was no significance in the relation between lead and serum levels of otehr lipids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.262-267
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• 2013

The purpose of this research is to minimize the loss of nutrients in carrots (Daucus carota var. sativa). A protopectinase was used to enzymatically macerated and separate cells without damage. The enzyme modification group's collection rate was 81% (residue rate 19%), while the grinding process group's collection rate was 56% (residue rate 44%)-an over 20% of collection rate difference. Thus we predicted a big difference in transference number after the process and wastage. In comparing ingredient changes in the enzyme modification group versus the grinding process group, the content of ${\beta}$-carotene (the carrot's main ingredient) showed a change in protection factor (PF) ($2.2{\pm}0.2$ PF, $1.4{\pm}0.4$ PF, respectively), total polyphenol content ($89{\pm}3.42{\mu}g/g$, $64{\pm}4.16{\mu}g/g$, respectively), and total flavonoid content ($68{\pm}2.73{\mu}g/g$, $41{\pm}3.26{\mu}g/g$, respectively). Thus we confirmed that nutrient destruction, due to cell membrane preservation, occurred less often in the enzyme modification process than the mechanical grinding process group. We also measured DPPH radical scavenging activity, hydroxyl radical scavenging activity, and nitrite scavenging activity. DPPH radical scavenging activity was $87{\pm}0.29%$ and $74{\pm}1.56%$ in the enzymatic modification group compared to the mechanical grinding process group, respectively. Hydroxyl radical scavenging activity was $44{\pm}0.49%$ and $32{\pm}0.48%$ in the enzymatic modification group compared to the mechanical grinding process group, respectively. Nitrite scavenging activity was $59{\pm}0.53%$ and $46{\pm}0.62%$ in the enzymatic modification group compared to the mechanical grinding process group, respectively. Our results show that cell membrane preservation, via the protopectinase enzyme process, decreases the loss of nutrients and still preserves inherent antioxidants.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.515-518
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• 2003

Six mature purebred Angus cows ($3.5{\pm}1.5$ years of age, $631.36{\pm}8.63kg$), three pregnant ($250{\pm}7$ days pregnant) and three non-pregnant and eight mature Suffolk ewes ($5{\pm}1.2$ years of age, $68.18{\pm}2.3kg$) four pregnant $115{\pm}5$ days pregnant) and four nonpregnant were utilized in a five-day metabolic trial to determine the effects of gestational status (pregnant vs. non-pregnant) on apparent absorption and retention of copper (Cu) and zinc (Zn). Animals were selected based on body weight, age, and gestational status, and randomly assigned to metabolic crates for total fecal and urine collection. Animals were allowed to acclimate to their new environment for seven days. Pregnant and non-pregnant cows and ewes were then paired (within a species) by body weight and pair-fed throughout the 5 day collection period. Copper and Zn intakes were similar for pregnant and non-pregnant animals within a species. Apparent absorption of Cu (p<0.06) and Zn (p<0.04) were higher in pregnant cows relative to non-pregnant cows. Pregnant cows also had a higher apparent retention of Cu (p<0.05) and Zn (p<0.06) relative to non-pregnant cows. Pregnant ewes had a higher (p<0.01) apparent absorption and retention of Zn compared to non-pregnant ewes. However, apparent absorption and retention of Cu were similar for pregnant and non-pregnant ewes. These data indicate that certain physiological and/or metabolic parameters are altered in pregnant cows and ewes consuming an alfalfa-based diet that enhance the apparent absorption and retention of certain trace minerals.

• Korean Journal of Poultry Science
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• v.33 no.2
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• pp.165-169
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• 2006

The objective of this study was to elucidate the basis for the difference in sperm production of broiler breeders. Nine sexually mature Hubbard broiler breeder males, 35 weeks of age, were trained for two weeks for semen collection on alternate days by abdominal massage technique. Following the training, the breeder males were collected daily for five successive days. The males were then classified as low or high sperm producers. The mean body weights of individual males were also recorded on the basis of body weight at the start and end of the experiment. Immediately after last collection the males were slaughtered and testes biometry was determined. Daily sperm output of individual males varied from $0.21{\times}10^9\;to\;2.64{\times}10^9$ sperm. The daily sperm production of low sperm producer males was lower ($0.47{\pm}0.13\;vs.\;2.06{\pm}0.20{\times}10^9$; P<0.05) than high sperm producer males. Testes weight of low sperm producer males was lower ($6.32{\pm}1.6\;vs.\;20.33{\pm}4.76\;gm$; P<0.05) than high sperm producer males. Moreover the testis weight of high sperm producer males was 3.22 times higher than low sperm producer males. The average body weight of high sperm producer males was higher ($4,389{\pm}116.3\;vs.\;3,960{\pm}131.77\;gm$; P>0.05) than low sperm producer males. The correlation coefficients indicate significantly positive correlation of body weight (P<0.05) and testes weight (P<0.01) on semen volume, sperm concentration and daily sperm production.

• Particle and aerosol research
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• v.18 no.4
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• pp.109-127
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• 2022

Recently, low-cost particulate matter (PM) sensors have been widely used in monitoring mass concentration. Maintaining the accuracy of the sensors is important and requires rigorous performance evaluation and calibration. In this study, two commercial low-cost PM sensors(LCS), Plantower PMS3003 and Plantower PMS7003, were evaluated in the laboratory and field with a reference-grade PM monitor (GRIMM 11-D). Laboratory evaluation was conducted with single/mixed particles of PSL (Poly Styrene Latex) in an acrylic chamber at 20℃ and relative humidity of 20%. Field evaluation was conducted inside a building of Yonsei University (Shinchon) from February 12 to March 31, 2022. In both evaluations, LCS measured values became different from reference measured values when the relative humidity was high or the outdoor air PM10/PM2.5 ratio was high. Based on the field evaluation, the LCS measured values were corrected through four different regression analysis models. As a result, the multivariate polynomial regression analysis model showed highest matching with the reference PM monitor (PM2.5 >0.9, PM10 >0.85). In this model, the PM10/PM2.5 ratio and relative humidity were chosen as independent variables.