• Smart Structures and Systems
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• v.12 no.1
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• pp.41-54
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• 2013

Concrete is known as a heterogeneous product which is composed of complex chemical composition and reaction. The development of concrete thermal effect during early age is critical on its future structural health and long term durability. When cement is mixed with water, the exothermic chemical reaction generates hydration heat, which raises the temperature within the concrete. Consequently, cracking may occur if the concrete temperature rises too high or if there is a large temperature difference between the interior and the exterior of concrete structures during early age hydration. This paper describes the contribution of novel Fabry-Perot (FP) fiber optic temperature sensors to investigate the thermal effects of concrete hydration process. Concrete specimens were manufactured under various water-to-cement (w/c) ratios from 0.40 to 0.60. During the first 24 hours of concreting, two FP fiber optic temperature sensors were inserted into concrete specimens with the protection of copper tubing to monitor the surface and core temperature change. The experimental results revealed effects of w/c ratios on surface and core temperature developments during early age hydration, as well as demonstrating that FP fiber optic sensors are capable of capturing temperature variation in the concrete with reliable performance. Temperature profiles are used for calculating the apparent activation energy ($E_a$) and the heat of hydration (H(t)) of concrete, which can help us to better understand cement hydration.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.6
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• pp.70-77
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• 2000

In this paper, the effect of solution and age heat treatment to the corrosion behavior for the Ti-6Al-4V alloy were studied by cyclic polarization methods. Ti-6Al-4V was solution heat treated at $1,066^{\circ}C$ and $966^{\circ}C$ for 5 hours, and followed by age heat treated at $650^{\circ}C$, $600^{\circ}C$ and $550^{\circ}C$ with 1, 2, 4, 8 and 16 hours under vacuum environment. Test solution was 3.5% NaCl with temperature $25^{\circ}C$. The obtained results were as follows: 1. Base metal was exhibited higher electrical charge than that of solution and aged material. With decrease of solution-treatment temperature from 1066 to $966^{\circ}C$, the electrical charge was increased due to softening of micro structure. 2. The corrosion resistance of specimen that solution treated at $966^{\circ}C$ for 5 hours and age heat treated at 650, 660 and $550^{\circ}C$ were increased with increase of aging time to 4, 8 and 16 hours respectively, and then decreased. 3. In case of 316L stainless steel, measured charge and corrosion potential was 0.0627 coulomb and -614 mV respectively. Corrosion resistance of Ti-6Al-4V was higher than that of 316L.

• Journal of Life Science
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• v.19 no.1
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• pp.138-146
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• 2009

Garlic (Allium sativum) are an agronomically important genus because of their sulfur flavour components. The majority of the volatiles flavour principles are generated through the enzymatic hydrolysis of the non-volatile organosulfur compounds. However, these compounds may be possible sources of new novel bioacuve and therapeutic principles. Garlic has strong antioxidant activity, and epidemiological studies support the fad that diets rich of garlic may prevent some of the chronic diseases. The health cares of garlic likely arise from a wide variety of components, which may work synergistically. The chemical changes of garlic composition makes it plausible that a variation in processing can lead to acquisition of differential chemical compositions of garlic products. Especially highly unstable allicin can easily disappear during processing and are quickly transformed into a various organosulfur compounds. Various supplements of garlic, particularly aged garlic extract (AGE), are known to possess a promising antioxidant potential and are effective in prevention of chronic diseases because of the bioactive constituents. Although all of active ingredients of AGE are not elucidated, water-soluble components of AGE, including S-allylcysteine, S-allylmercaptane, steroid saponins, tetrahydro-${\beta}$-carboline derivatives, and fructosyl-arginine, appears to be associated with the pharmacological effects of AGE. Consequently, the allicin free garlic components such as S-allylcysteine, S-allylmercaptane, steroid saponins, tetrahydro-${\beta}$-carboline derivatives, and fructosyl-arginine can be applicable to standardization of the quality of commercial garlic products. This review provides an insight into garlic's biomarkers and presents evidence that they may either prevent or delay chronic disease associated with aging.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2847-2850
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• 2014

Background: Retinoblastoma is a rare malignant intraocular neoplasm. About 90% of cases feature a germline mutation in the RB1 gene and these will develop retinoblastoma during their early childhood. An association between mutations in germline cells and aging has been demonstrated. This suggests a higher incidence of childhood cancer including retinoblastoma among children of older parents. Materials and Methods: In the present study we aimed to determine the association of paternal and maternal age with an increased risk of retinoblastoma in a case-control study in Iranian population. The study was carried out on 240 persons who were born during 1984-2012 in Mahak and Mofid hospitals in Tehran, Iran. The statistical analysis included studying the mean age of parents and in order to know whether parental age of patients is different from parental age of control group, (t-test) compare averages test is used perfectly. By binary logistic regression, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Results: The results of statistical analysis including the study of mean parental age by the use of (t-test) compare averages test showed a significant difference between parental ages of patients and controls. Logistic regression showed that coefficients were significant for maternal but not paternal age. Conclusions: Our findings indicate that advanced maternal age can increase the risk of retinoblastoma in offspring, but the paternal age has no significant effect.

• Journal of Nutrition and Health
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• v.36 no.8
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• pp.851-858
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• 2003

Sister chromatid exchange (SCE) has recently become a common cytogenic assay system for detecting exposure to chemical mutagens and carcinogens. One application of SCE is the monitoring of populations believed to have been exposed to such agents. A cross-sectional study of SCE frequency in peripheral blood lymphocytes from 45 Koreans aged 61 to 84 years was conducted. The effect of cigarette smoking and age on SCE was assessed by different degrees of smoking status such as smokers (n = 14), ex-smokers (n = 16) and non-smokers (n = 15). Mean spontaneous SCE per cell for the smokers (11.5 $\pm$ 1.1) was significantly higher (p < 0.05) than that for the non-smokers (8.8 $\pm$ 0.3). However, mean SCE frequencies per cell for the ex-smokers (10.3 $\pm$ 0.6) were not significantly different from those of the smokers or the non-smokers. The smokers showed an increased number of high SCE frequency cells (HFCs) when compared to the ex-smokers and non-smokers (p < 0.05). The mean SCE frequencies of the non-smokers showed a statistically significant increase (p < 0.05) with the subject's age. These results show that age and smoking habits contribute a great deal in setting a higher degree of basal DNA damage in elderly Koreans, and smoking appeared to be a more significant damaging factor than age.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.391-398
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• 2011

After a concrete is poured, reinforced concrete structures were distressed by physical and chemical factor over time. It is in need to define important variables related to structural behavior for effectively conducting seismic analysis of structures with age-related degradation. In this study, a sensibility analysis using the first-order second moment method was performed to analyze an important variables for the reinforced concrete shear wall with age-related degradation. Because the seismic capacity of aging structures without a concrete hardening effect can be underestimated, the sensibility of analysis variables was analyzed according to the concrete hardening. Important variables for RC shear wall with age-related degradation was presented by using the tornado diagram.

• Korean Journal of Veterinary Research
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• v.30 no.2
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• pp.163-170
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• 1990

The blood chemical values and blood enzyme activities were examined from 74 healthy mixed breed dogs in the area of Seoul. The results obtained are summarized as follows; 1. Mean${\pm}$SD values and ranges of glucose were $61.97{\pm}8.41mg/100ml$ and 47.28~81.67mg/100ml, of blood urea nitrogen(BUN) $15.99{\pm}2.31mg/100ml$ and 8.21~21.31mg/100ml, of total protein(TP) $8.17{\pm}0.93g/100ml$ and 6.06~9.91g/100ml, of albumin $4.16{\pm}0.47g/100ml$ and 2.81~5.15g/100ml, of globulin, $4.01{\pm}0.64g/100ml$ and 2.72~5.54g/100ml, of albumin/globulin(A/G) ratio $1.06{\pm}0.17$ and 0.71~1.42, of cholesterol(Chol) $187.33{\pm}19.78mg/100ml$ and 128.70~222.90mg/100ml, of total bilirubin(TB) $0.73{\pm}0.14mg/100ml$ and 0.43~1.16mg/100ml, of phosphorus(Pi) $5.25{\pm}1.00mg/100ml$ and 2.61~7.72mg/100ml, of calcium(Ca) $10.76{\pm}1.08mg/100ml$ and 8.24~12.60mg/100ml, of triglyceride(TG) $89.48{\pm}21.16mg/100ml$ and 47.80~133.00mg/100ml, respectively. 2. The glucose value in the age group of 7~12 months was higher (p<0.01) but in the age group of 3~4 years was lower (p<0.05) than the total glucose value. The TP value in the age group of 7~12 months was lower (p<0.01) but in the age group of 1~2 years was higher (p<0.05) than the total TP value. The globulin value in the age group of 7~12 months was lower (p<0.01) but in the group of 1~2 years was higher (p<0.01) than the total globulin value. The A/G ratio value in the age group of 7~12 months was higher (p<0.05) but in the age group of 1~2 years was lower (p<0.05) than the total A/G ratio value. The phosphorus values in the age group of 1~2 years and the age group of 3~4 years were lower (p<0.01, p<0.001) than the total phosphorus value. The calcium value in the age group of less than 6 months was higher (p<0.05) but in the age group of 7~12 months was lower (p<0.001) than the total calcium value. 3. Mean${\pm}$S.D. values and ranges of alkaline phosphatase(AP) were $72.47{\pm}19.73IU/l$, and 28.13~105.00IU/l, of lactic dehydrogense(LDH) $159.46{\pm}45.11IU/l$ and 60.63~265.30IU/l, of serum aspartate aminotransferase(AST) $38.64{\pm}8.62IU/l$ and 21.47~70.58IU/l, of serum alanine aminotransferase(ALT) $34.88{\pm}11.30IU/l$ and 14.51~73.17IU/l, respectively. 4. The AP value in the age group of 7~12 months was higher (p<0.05) but in the age group of 1~2 years was lower (p<0.01, p<0.001) than the total AP value. The LDH value in the age group of less than 6 months was higher (p<0.001) but in the age group of 1~2 years and the age group of 3~4 years were lower (p<0.05) than the total LDH value. The serum AST value in the age group of 3~4 years was lower (p<0.01) than the total SGOT value. The serum ALT value in the age group of 7~12 months was higher(p<0.05) than the total SGPT value.

• Economic and Environmental Geology
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• v.19 no.spc
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• pp.151-162
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• 1986

The older granitic rocks of the study area are composed of mainly orthogneiss and foliated granite. These rocks shows mostly mortar or fiaser structure by strong mylonitization and thermal metamorphism during several orogenies. $^{40}Ar-^{39}Ar$ incremental·release ages of these rocks have been determined for 6 hornblende. 7 muscovite and 4 biotite concentrates separated from rocks collected across the Ryeongnam massif. Most $^{40}Ar-^{39}Ar$ age are discordant with Rb-Sr whole rock age of the same area. These ages range from 1998 to 172Ma. This discordant age is interpreted to indicate that samples were in contact with Daebo granite body that was characterized by large and variable $^{40}Ar-^{39}Ar$ ratios. Such ratios most likely resulted from widespread diffusion of the argon liberated from older granitic rocks during several metamorphic overprint. The general trend of the chemical composition of these rocks suggest that most of them are some series of differentiated products by fractional crystallization.

• Journal of Oral Medicine and Pain
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• v.8 no.1
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• pp.127-142
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• 1983

This thesis was to investigate sex defferencd by employing the methodes of Bernadskij's and it's modification by means of the evaluation of pH of dentin in 162 extracted teeth. The obtained were as follows: 1. In 72% of all experinments, pH of human dentin substance was higher in female than in male. Mean pH was 13.175±0.031 in male and 13.245±0.030 in female. 2. After comparative studies on each pH in anatomical region of tooth arrangement, the sex difference of pH was most obviously showed in molars. 3. In pH change according to ages, the 30's was the highest in male and the 20's in female, also pH showed decresing tendency by the increasing of age in both male and female. 4. There was no pH difference in anatomical regions of tooth arrangment. 5. Mean pH was 13.282±0.013 in under 50 years of age and 13.282±0.022 over 50. It proved that pH was higher in under 50 years of age than in over 50.

• The Journal of the Petrological Society of Korea
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• v.3 no.2
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• pp.128-137
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• 1994

The northeastern shore of the Anmyondo consists mainly of tuff, basalt, andesite and dacite. The K-Ar ages of the two mugearites are $89.4{\pm}2.4$ Ma and $91.9{\pm}2.3$ Ma which correspond to the middle Cretaceous age. Petrochemical reviews on the volanic rocks of the Cretaceous, Tertiary and Quaternary ages in the Korean Peninsula show that marked differences exist in chemical compositions according to the age of eruption.