• Journal of Sensor Science and Technology
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• v.25 no.1
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• pp.51-56
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• 2016

This study evaluates the performance of an optical sensor and measurement system (CMA-24) which can analyze the fluctuation of dissolved oxygen and pH simultaneously. In the optical sensor system, the fluorescent materials, Rudpp and HPTS which are sensitive to dissolved oxygen and pH, respectively, are coated on the bottom of a 24-well -plate by the sol-gel technology. The detection times of the emission light of the oxygen sensor were $4,186{\pm}13.90{\mu}s$ and $4,452{\pm}36.68{\mu}s$ for the dissolved oxygen of 17% $O_2$ and 7.6% $O_2$, respectively. On the other hand, the detection times of the pH sensor were $6,699.43{\pm}14.64{\mu}s$, $6,722.24{\pm}6.21{\mu}s$, and $6,748.52{\pm}2.63{\mu}s$ using pH 6, 7, and 8, respectively. When we determined cellular respiration levels of C2C12 myocytes with CMA-24, $O_2$/pH measurement system, the ratio of the uncoupled to coupled OCR (oxygen consumption rate) was 1.41. The results mean that this CMA-24 system shows almost the same sensitiveness as the commercial system.

• Analytical Science and Technology
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• v.24 no.4
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• pp.304-309
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• 2011

In this research, behaviour of turbidity and phosphorus in water and soil dependent upon pH and a change of water was studied. Phosphorus dissolve rate from turbidity was increased for water if potential of hydrogen was less than pH 4 or more than pH 7. Turbidity release rate from soil was increased with pH. Turbidity release rate from soil was drastically increased for water if potential of hydrogen was more than pH 4. turbidity release rate from soil was stabilized more than pH 6. Dissolved phosphorus was increased from 2 hours to 24 hours and stabilized in 24 hours. Turbidity was reached the peak of 24 hours and decreased from 24 hours to 96 hours. Turbidity and dissolved phosphorus was decreased for water if these samples were changed a overlying water. Behaviour of turbidity was analogous to dissolved phosphorus when potential of hydrogen was increased from pH 6 to pH 10 and a change of overlying water was increased from 1 time to 4 times. These results suggest that phosphorus dissolve rate and turbidity were directiy correlated with pH. These results are of great importance in lakes because most lakes have a pH in the range of pH 7-10.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.742-747
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• 1995

The effect of storage temperature and period on the contents of tin, iron, lead and vitamin C, browning index and pH was studied for canned and bottled orange juices currently sold in Korean market, which were stored for 24 weeks at 20, 30, 40 and $50^{\circ}C$ and analyzed at 4 week intervals. The change of metal content in bottled juices was negligible but metal release in canned juices was remarkably affected by storage temperature. Tin content after 16 weeks increased by $2.7{\sim}13.1$ times, iron content after 24 weeks increased by $4.3{\sim}5.2$ times and lead content after 24 weeks increased by $1.1{\sim}2.9$ times. Retention of total ascorbic acid in canned juices after 24 weeks at $30{\sim}50^{\circ}$ decreased to $13{\sim}76%$, while that in bottled juices decreased to $4{\sim}80%$. Browning index in canned juices after 24 weeks below $40^{\circ}C$ increased slightly with serious discoloration at $50^{\circ}C$ while that in bottled juices increased a little rapid. pH change in canned and bottled juices during storage below $40^{\circ}C$ was not observed regardless of container type but a great change of pH was accompanied with swelling of container ends in the case of canned juices after 24 weeks at $50^{\circ}C$.

• Korean Journal of Mathematics
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• v.24 no.4
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• pp.751-764
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• 2016

We investigate the self-dual codes over Galois rings and determine the mass formula for self-dual codes over Galois rings $GR(p^2,2)$.

• Korean Journal of Mathematics
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• v.24 no.2
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• pp.297-305
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• 2016

In this paper, by using fixed point theorem, we obtain the stability of the following functional equations $$f(pr,qs)+g(ps,qr)={\theta}(p,q,r,s)f(p,q)h(r,s)\\f(pr,qs)+g(ps,qr)={\theta}(p,q,r,s)g(p,q)h(r,s)$$, where G is a commutative semigroup, ${\theta}:G^4{\rightarrow}{\mathbb{R}}_k$ a function and f, g, h are functionals on $G^2$.

• Journal of radiological science and technology
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• v.4 no.1
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• pp.73-80
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• 1981

Radioactive phosphorus(P-32) was injected to the chicken in the purpose of determination of the uptake and distribution, as related to sex and hour differences of the various organs of the body. $2{\mu}Ci$ of P-32 were injected to each chicken and the distribution of P-32 was observed at 1 hr, 6 hrs, 12 hrs, 24 hrs and 48 hrs after injection. In this experiment 34 heads of chicken were used(30 chicken for P-32, 4 chicken for control group) and the results obtained as follows: 1. The uptake of P-32 per gram of various organ in g. mm, femur(1 hr), liver, femur, tibia(24 hrs) and tibia(48 hrs) exhibited higher in the male than the female. 2. The uptake of P-32 per gram of various organ in heart, kidney, ovary(1 hr), kidney, brain(24 hrs) and kidney(48 hrs)exhibited higher in the female than the male. 3. The uptake ratio of brain, spleen, g. mm and tibia were increased gradually by the 12 hrs after injection of P-32, but decreased in liver, heart and kidney by the 24 hrs. 4. The uptake ratio of the femur was increased gradually by the 24 hrs, but testis and ovary was increased after 24 hrs. 5. The organs showed an uptake of P-32 per gram of various organ, with the following sequence : femur, tibia, testis or ovary, spleen, liver, kidney, heart, g. mm and brain.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.19 no.2
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• pp.136-141
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• 2008

Background and Objectives: Laryngopharyngeal reflux (LPR) is a very common disease among outpatients of department of otorhinolaryngology. Although there are several diagnostic tools for LPR disease and ambulatory 24-hour double-probe pH monitoring is gold standard method, empirical diagnosis by reflux symptom index and reflux finding score (RFS) are mainly used. So we analyzed the relationship between ambulatory 24-hour double-probe pH monitoring and RFS in patients with LPR. Subjective and Method: Fifty patients with LPR symptoms and abnormal RFS and ambulatory 24-hour double probe monitoring were enrolled. Each items and sum of laryngeal reflux score were compared the results of ambulatory 24-hour double-probe pH monitoring in upper (UES) and lower (LES) esophageal sphincter. Results: There were no significant correlation between the results of ambulatory 24-hour double-probe pH monitoring in UES (pH<4 and pH<5) and each item and sum of RFS. However, supine time and reflux number of UES (pH<5) were showed the partial correlations with diffuse laryngeal edema and thick endolaryngeal mucus (p=0.03, p=0.01). Although there were no relationship between the results of ambulatory 24-hour double-probe pH monitoring in LES and sum of RFS, the significant correlations presented between granuloma and total time (p=0.008), upright time (p=0.008, reflux number (p=0.049) of LES. Conclusion: Although granuloma among items of RFS showed significantly correlation with the results of ambulatory 24-hour double-probe pH monitoring in LES, there were no significant correlation between the results of ambulatory 24-hour double-probe pH monitoring in UES and LES and items and sum of RFS.

• Journal of Life Science
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• v.20 no.4
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• pp.487-495
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• 2010

A microorganism hydrolyzing carboxymethylcellulose (CMC) was isolated from seawater, identified as Psychrobacter aquimaris by analysis of 16S rDNA sequences, and named P. aquimari LBH-10. This strain produced an acidic carboxymethylcellulase (CMCase), which hydrolyzed carboxymethylcellulose (CMC), cellobiose, curdlan, filter paper, p-nitrophenyl-$\beta$-D-glucopyranoside (pNPG), pullulan, and xylan, but there was no detectable activity on avicel and cellulose. The optimal temperature for CMCase produced by P. aquimari LBH-10 was $50^{\circ}C$ and more than 90% of its original activity was maintained at broad temperatures ranging from 20 to $50^{\circ}C$ after 24 hr. The optimal pH of the CMCase was 3.5, and more than 70% of its original activity was maintained under acidic conditions between pH 2.5 and 7.0 at $50^{\circ}C$ after 24 hr. The optimal pH of CMCase produced by P. aquimaris LBH-10 seems to be lower than those produced by any other bacterial and fungal strain. $CoCl_2$, EDTA, and $PbCl_2$ at a concentration of 0.1 M enhanced CMCase-produced P. aquimaris LBH-10, whereas $HgCl_2$, KCl, $MnCl_2$, $NiCl_2$, and $SrCl_2$ inhibited it.

• Journal of Environmental Health Sciences
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• v.21 no.2
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• pp.27-35
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• 1995

In order to investigate acute toxicity and bioconcentration of heavy metals for a freshwater fish, the fish used in this experiment was goldfish, Carassius auratus. Each ten goldfish was accommonidated in a water and was treated with different concentration of Pb and Cu compound. The 24 $hr-LC_{50}$ was obtained by plotting on the log-normal distribution graph. Furthermore, the combined effect of Pb and Cu was also investigated the fish was treated with Pb or Cu compound only, and Pb and Cu compound together, respectively. These results were summarized as follows: 1. The 24 $hr-LC_{50}'s$ of Pb and Cu were 7.48 mg/l and 0.666 mg/l, respectively. 2. When single or/and combined treatment with Pb(7.0 mg/l) or/and Cu(0.6 mg/l) to Carassius auratus for 24 hours were performed, there was significant difference between the single or/and the combined treatment in their bioaccumulated Cu concentrations. Cu concentrations in goldfish were higher in the combined treatment than in the single treatment. 3. When Carassius auratus was exposed to 0.748 mg/l (1/10 of 24 $hr-LC_{50}$) and 1.496 mg/l of Pb (1/5 of 24 $hr-LC_{50}$) for 7 days, the bioconcentration factors (BCF) were 79.14 and 100.11 for Pb, respectively. The BCF of Pb was obtained as a linearity according to the concentration and exposure time as follows log BCF=1.014 log $P\cdot T$+1.011 ($r^2$=0.9041) where, P: pollutant concentration(mg/l) T: exposure time(day) 4. When Carassius auratus was pxposed to 0.0666 mg/l (1/10 of 24 $hr-LC_{50}$) and 0.1332 mg/l of Cu (1/5 of 24 $hr-LC_{50}$) for 7 days, the bioconcentration factors (BCF) were 55.42 and 63.24 for Cu respectively. The BCF of Cu was obtained as a linearity according to the concentration and exposure time as follows log BCF=0.571 log $P\cdot T$+1.823 ($r^2$=0.8974) where, P: polutant concentration(mg/l) T: exposure time(day)

• Journal of the Korean Ceramic Society
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• v.37 no.11
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• pp.1105-1113
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• 2000

Bioglass 조성 중 45S5 (46.1SiO$_2$.24.4$Na_2$O.26.9CaO.2.6P$_2$O$_{5}$ : 몰비)를 기본 조성으로 하여 46P4 (46.2SiO$_2$.49.5CaO.4.3P$_2$O$_{5}$ : 몰비), 46SF (46.1SiO$_2$24.4$Na_2$O.16.1CaO.2.6P$_2$O$_{5}$.10.8CaF : 몰비) 그리고 55SF (55.1SiO$_2$.9.2$Na_2$O.27.8CaO.3.4P$_2$O$_{5}$.4.5CaF : 몰비)를 제조하여 tris-완충용액 및 유사 생체용액(simulated body fluid)에서 반응시킨 후 생체활성유리의 표면에 생성되는 아파타이트 결정형에 관하여 연구하였다. 45S5 유리를 tris-완충용액에 반응시켰을 경우 6시간 반응시부터 수산화 아파타이트가 생성되었으나 유사 생체용액에 반응시켰을 경우에는 24시간까지도 수산화 아파타이트 결정이 생성되지 못하고 비정질 상태의 칼슘 인산염만 형성되었다. tris-완충용액에 각 조성의 유리를 200시간 반응시킨 경우 불소를 함유하지 않은 유리에서는 잎사귀 모양의 수산화 아파타이트가, 불소를 함유한 유리에서는 구상의 플루오르 아파타이트가 형성되었다. 그러나 유사 생체용액에 각 조성의 유리를 200시간 반응시켰을 경우 불소를 함유하지 않은 유리에서는 누에고치형의 수산화 아파타이트가 형성되었고 불소를 함유한 유리에서는 무정형의 칼슘 인산염이 생성되었다.