• Journal of the Korea Concrete Institute
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• v.19 no.5
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• pp.613-621
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• 2007

Due to the increasing significance of durability, much researches on carbonation, one of the major deterioration phenomena are carried out. However, conventional researches based on fully hardened concrete are focused on prediction of carbonation depth and they sometimes cause errors. In contrast with steel members, behaviors in early-aged concrete such as porosity and hydrates (calcium hydroxide) are very important and may be changed under carbonation process. Because transportation of deteriorating factors is mainly dependent on porosity and saturation, it is desirable to consider these changes in behaviors in early-aged concrete under carbonation for reasonable analysis of durability in long term exposure or combined deterioration. As for porosity, unless the decrease in $CO_2$ diffusion due to change in porosity is considered, the results from the prediction is overestimated. The carbonation depth and characteristics of pore water are mainly determined by amount of calcium hydroxide, and bound chloride content in carbonated concrete is also affected. So Analysis based on test for hydration and porosity is recently carried out for evaluation of carbonation characteristics. In this study, changes in porosity and hydrate $(Ca(OH)_2)$ under carbonation process are performed through the tests. Mercury Intrusion Porosimetry (MIP) for changed porosity, Thermogravimetric Analysis (TGA) for amount of $(Ca(OH)_2)$ are carried out respectively and analysis technique for porosity and hydrates under carbonation is developed utilizing modeling for behavior in early-aged concrete such as multi component hydration heat model (MCHHM) and micro pore structure formation model (MPSFM). The results from developed technique is in reasonable agreement with experimental data, respectively and they are evaluated to be used for analysis of chloride behavior in carbonated concrete.

• Journal of Nutrition and Health
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• v.4 no.1
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• pp.1-19
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• 1971

Nutritional anemia is an important nutritional problem affecting large population groups in most developing countries. Nutritional anemia is caused by the absence of any dietary essential involed in hemoglobin formation or by poor absorption of these dietary components. The most likely causes are lack of dietary iron, and folate, vitamin $B_{12}$ and high qualify protein. Anemia is considered to be a late mainfeastation of nutritional deficiencies, and even mild anemia is not the earilest sign of such a deficiency. Therefore, the object of therapy is to correct underlying deficiency rather than merely its manifestation. Iron deficiency anemia is generally much the most common form of anemia. And it is very prevalent particularly in pregnant women and young children, especially under five year of life. According to the rapid growth rate of infants, dietary iron should he provided for infants over three months of age in adequate amounts for the synthesis of hemoglobin required by the increasing blood volume and for the demands of newly formed cells. The principal causes of iron deficiency anemia are an inadequate dietary iron content, interference with absorption of iron from the intestine, excessive losses of iron from the body, disturbance of iron metabolism by infection, and social and cultural environments. The present study is planned to obtain informations concerning nutritional anemia through anthropometric and biochemical determinations for the assessment of nutriture in pre-school children. Determination was taken in 226 pre-school children in ruraI arae in 1968, 122 pre-school children in 1970, and 1526 hospitalized pre-school children in 1970. The results of this study are as follows; (1) According to Iowa Malnutrition Borderline (85 percentile) for weight, the proportions of underweighed pre-school boys and girls in rural area were 47.2% and 46.2% in1968, and were 36.1% and 51.8% in 1970. According to Iowa Malnutrition Borderline for height, the proportions of underheight boys and girls in rural area were 30.5% and 33.7%, and were 26.2% and 21.8% in 1970. Malnutrition scores of underweight for height values of boys and girls in rural area were 19.3 and 17.3 in 1968, and the scores of boys and girls were 15.6 and 15.5 in 1970. (2) The mean hemoglobin values of boys and girls in rural area were $11.2{\pm}1.8g/100ml\;and\;11.4{\pm}1.6g/100ml$ in 1968. In 1970, the mean values of boys and girls in rural area were $11.3{\pm}1.3g/100ml\;and\;11.7{\pm}2.4g/100ml$. The mean hemoglobin values of hospitalized boys and girls were $11.9{\pm}2.2g/100ml\;and\;11.7{\pm}2.4g/100ml$ in 1970. It is found that 92 of 215 children (42.7%) in rural area had concentrations of hemoglobin less than 11.0g/100ml in 1968. In 1970, 55 of 121 children (45.4%) in rural area and 559 of 1526 hospitalized children (36.6%) had concentrations of hemoglobin less than 11.0g/100ml. (3) The mean hematocrit levels of hospitalized boys and girls were $35{\pm}26.8%\;and\;35.4{\pm}6.4%$ in 1970. And 443 of 1334 hospitalized children (33.2%) had hematocrit values below 33%. (4) The average mean corpuscular hemoglobin concentration levels of hospitalized boys and girls were $32.4{\pm}2.2\;and\;32.3{\pm}2.2$ in 1970. And 1016 of 1352 hospitalized children (75.1%) had the mean corpuscular hemoglobin values below 34. (5) The mean iron values of young children in rural area and hospitalized children were $62.0{\pm}6.3{\mu}g/100ml\;and\;60.7{\pm}22.8{\mu}g/100ml$. The proportions of anemia cases below $50{\mu}g/100ml$ in rural area was 37.9%, and 34.3% in hospitalized children. (6) The mean total iron binding capacity of young children in rural area was $376{\pm}57.88{\mu}g/100ml,\;and\;342.2{\pm}6.15{\mu}g/100ml$ in hospitalized children. (7) The average transferrin saturation percentage of young children in rural area was $16.9{\pm}4.7%,\;and\;18.0{\pm}8.4%$ in hospitalized children. The proportions of anemia cases below 15% of young chi1dren in rural area and hospitalized children were 48.3% and 41.2%. Therefore, authors wish to recommend that the following further studies should be undertaken: (1) Standardization of simplied laboratory examination of nutritional anemia. (2) The prevalence of nutritional anemia and the requirements of iron, folate, and vitamin $B_{12}$ of pre-school children. (3) The content and absorption of iron in Korean food. (4) The pathogenesis of nutritional anemia and prevention of parasitic disease. (5) Maternal health and nutrition education.

• Clinical and Experimental Pediatrics
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• v.49 no.5
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• pp.523-528
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• 2006

Purpose : The purpose of this study was to investigate the relationship between depression and resilience in adolescents with congenital heart disease(CHD) and to identify the variables associated with depression. Methods : The Resilience Scale(cronbach's ${\alpha}=0.92$), Children's Depression Inventory(cronbach's ${\alpha}=0.72$) and Maternal Behavior Research Instrument(cronbach's ${\alpha}=0.88$) were applied and analyzed to assess depression and resilience among 231 adolescents after surgery for CHD from three major cardiac centers in Korea. This group consist of 114 males and 117 females. The mean age was 15.8 years(range : 13-18 years). The clinical severity of illness was rated by CHD functional index and NYHA functional class. Results : The mean score for depression and resilience was 16.74(range : 0-49) and 115.84(range : 70-132) respectively. Depression was significantly related to age(r=0.25, P<0.001) and NYHA functional class(r=0.35, P<0.001), as well as being negatively correlated with oxygen saturation(r=-0.39, P<0.001), academic achievement(r=-0.41, P<0.001), parental attitude(r=-0.49, P<0.001) and resilience (r=-0.59, P<0.001). The results of multiple regression analysis showed that parental attitude(${\beta}=-0.48$, P<0.01) and resilience(${\beta}=-0.62$, P<0.01) were related to depression. Conclusion : This study demonstrated that adolescents with CHD had a higher resilience and were less depressed with an affectionate parent. With respect to medical and nursing intervention programs, it is essential to identify strengths of adolescents with CHD in order to increase their resilience. Additionally, it is also important that parenting and counseling programs be implemented for the parents of adolescents with CHD.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.194-205
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• 1999

Hydrogeochemical variation and environmental isotope at the some abandoned metal mine (Sanggok, Keumsil, Jangpung and Samdeok) creeks of the Hwanggangri mining district were carried out based upon the physicochemical properties for surface water collected of February in 1998. Hydrogeochemical composition of the all water samples are characterized by the relatively significant enrichment of Ca$^{2}$, alkaline ions, N $O_3$$^{－}$ and Cl$^{－}$ in normal surface water, whereas the surface waters near the mining area are relatively enriched in Ca$^{2+$, Mg$^{2＋}$, heavy metals. HC $O_3$$^{－}$ and S $O_4$$^{2－}$. Surface waters of the mining creek have low pH, high EC and extremely high concentrations of TDS compared with surface water of the non-mining creeks. The range of $\delta$D and $\delta$$^{18}$O values (SMOW) in the waters are shown in －65.0 to－71.2$\textperthousand$ and －9.1 to－10.2$\textperthousand$. The d($\delta$D－$\delta$$^{18}$O) value with those of water samples ranged from 7.3 to 10.9. These $\delta$D and $\delta$$^{18/}$ of the acid mine water are more heavy values than those of surface water. The values have revealed the positive correlation between isotopic compositions and major elements, because those $\delta$D and $\delta$$^{18}$O values increase with increasing TDS. HC $O_3$$^{－}$ , S $O_4$$^{2－}$ and Ca$^{2＋}$ concentration. Using WATEQ4F, saturation index of albite calcite, dolomite and mostly clay minerals in water of the mining area show undersaturated and progressively evolved toward the equilibrium condition due to fresh water mixing, however, surface waters of the non-mining area are nearly saturated and/or supersaturated. Geochemical modeling showed that mostly toxic heavy metals within water in the mining creek may exist largely in the from of metal-sulfate (MS $O_4$$^{2－}$), free metal (M$^{2＋}$/), C $O_3$$^{－}$ and/or OH$^{－}$ complex ions. Based on the geology, water chemistry and environmental istopic data the water compositions from the Sanggok and Keumsil mine creek (consist mainly of Cambro-Ordovician carbonate rocks of the Cho-seon Supergroup) show higher PH, Ca$^{2＋}$, Mg$^{2＋}$ , HC $O_3$$^{－}$ and more heavy $\delta$D and $\delta$$^{18}$O values than those from the Jangpung and Samdeok mine creek (consist of age -unknown metasedimentary rocks of the Ogcheon Supergroup and/or Jurassic grani-toids), but each of these waters represents a similar hydrogeochemical evolution path by the mine water mixing.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.2
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• pp.99-105
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• 1976

After investigation of soil characteristics the properties of a reclaimed marine soil (Gupo series) distributed along the southern coastal areas of Korea are summarized as follows: 1. Gupo soils distributed in the southern Ria coastal area are derived from rolling to hilly materials and are poorly sorted with less influences of river fluvial action. These soils have high content of sand compared with the broad fluvio-marine soils in the western coastal areas. 2. The morphological features of the poorly drained Gupo soils are greyish brown sandy loam with a few yellowish mottles in the surface horizon and are grey sandy loam with a few gravel in the sub-strata. The ground water table remains around 10-30cm below the surface. These soils, recently reclaimed younger deposits, do not show any evidence of illuviation. 3. The "n" value (about 0.8) of the Gupo soils indicates physically unripened soils. 4. pH value of these soils shows more than 8.0 throughout the profile. Organic matter contents are extremely low (around 0.5%) except 1.2 percent in the surface horizon. C.E.C. ranges from 7 to 9m.e/100g which is lower than average in the country. The ratios of extractable cations such as Ca, Mg, Na and K of the surface horizon are 20:7:4:1. Base saturation is more than 60%. Available phosphate content is very low that is less than 25 ppm. Electric conductivity of the soils at $25^{\circ}C$ ranges 7 to 12 mmhos/cm and increased with depth. 5. According to classification of soil based on physical ripening, the Gupo soils can be classified into "Unripe soils with half-ripe sub-soils". The soils could be classified into "Hydric Haplaquents" in the original of the 7th Approximation (1960), but into "Typic Haplaqents in the supplement of 7th approximation which the physical ripening condition is not clearly expressed. Soil Taxonomy, apparently the final version of the 7th approximation, defines the soils as "Haplic Hydraquents" that clearly show the condition of physical ripening as well as other properties. Other several classification systems applied do not describe physical ripening condition of the soils.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.179-188
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• 1994

This study was conducted to investigate the distribution of potassium fractions and to establish the soil chemical indices for assessing potassium availability in upland soil. Soil samples were collected from 66 vegetable crop fields of Chungbuk Jungweon, Jeonbuk Imsil and Kyengbuk Euiseong and these samples were analyzed water soluble(W. S. -K), exchangeable(Exch. -K) and nonexchangeable potassium(Nonex. -K). The distribution of potassium fractions was examined for soils having different physico-chemical properties and compared with the soil parameters related to the potassium availability. 1. The distribution ranges of W.S.-K, Exch.-K and Nonex.-K were 0.07~1.42, 0.27~2.30, and 0.84~4.74me/100g, and average contents of relevent fractions were 0.40, 1.03 and 2.37me/100g respectively. 2. Contents of W.S.-K and Exch.-K were decreased with increasing soil pH, CEC, Exch. Ca and Exch. Mg contents but Nonex. -K showed a low correlationship with these factors. 3. Exch.-K content slightly inereased with increasing clay content, while W.S.-K and Nonex. -K contents were grandually decreased with clay contents. 4. The relationship between W.S.-K and Exch.-K was significant and W.S.-K was released from soil at 0.23me/100g content of Exch.-K 5. Contents of W.S-K and Exch.-K showed high correlationship with soil chemical parameters such as ratio of exchangeable cations(K/Ca+Mg), ratio of exchangeable cation equivalent[$K/{\sqrt{Ca+Mg}}:(me/100g)^{1/2}$], potassium exchangeable free energy(${\Delta}F=RT$ 1n $K/{\sqrt{Ca+Mg}}$ : calories/mole) and saturation percentage of potassium($Exch.K/CEC{\times}100$), and these factors were considered to be good parameters for assessing soil potassium availability.

• Journal of Chest Surgery
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• v.31 no.8
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• pp.749-755
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• 1998

Background: Twelve patients with acyanotic tetralogy of Fallot(TOF), characterized by the combination of a malaligned ventricular septal defect(VSD) and infundibular pulmonic stenosis with the clinical finding of acyanosis at rest, underwent surgical correction between January 1988 and July 1997. Materials and methods: 9.92% of patients with the diagnosis of TOF were acyanotic TOF in the same period. Ages ranged from 12 to 42 months(mean 25.2 months). 2D-echocardiographic studies, cardiac catheterization, and angiocardiograms were performed in all patients before operation. The preoperative mean systemic arterial oxygen saturation was 93.5%. According to the 2D-echocardiographic analysis, there was Lt-to-Rt shunt through VSD in 4 patients, bidirectional shunt in 2 patients, and no shunt in 6 patients. Results: The preoperative mean right ventricle to pulmonary artery(RV-PA) pressure gradients were 52.3 mmHg on 2D- echocardiogram and 48.4 mmHg on cardiac catheterization. The repair of ventricular septal defect was performed through a right atrial approach and the hypertrophic infundibular muscle bundles were resected by the transatrial and transpulmonary approach. Six patients(50%) received a transannular patch. The mean cardiopulmonary bypass time was 135.0 minutes, and the aortic crossclamp time was 87.8 minutes. Postoperative complications included bleeding necessitating reentry in one and chylothorax in one. No patient died after operation and there were no late deaths. Postoperative 2D-echocardiograms revealed tiny patch dehiscence in 5 cases and a moderate RV-PA pressure gradients(mean 15.3 mmHg). All patients were in New York Heart Association functional class 1 after operation. Conclusions: acyanotic TOF is the uncommon form of TOF, and acyanotic TOF can be repaired with a good outcome.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.820-825
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• 2007

Earthworm casting was the natural fertilizer that contained high concentrations of nutrients such as nitrogen, phosphate and potassium and of over $10^8$ CFU/ml of microorganisms. Greater than 80% of feed was excreted through the fermentation by the intestinal enzyme, after worm had eaten feeds such as fallen leaves and rotten roots under the ground. Also, the soil structure of casting was known to be very efficient in the aspects of the porosity, the water permeability, and deodorizing activities. In this research, the biofilter packed with a biomedia made of casting and waste polyurethane foam, a binder, which helped to improve the durability and perpetuity of casting, was investigated to degrade malodorous hydrogen sulfide gas. The biomedia had no need of extra supply of nutrients and of microbial inoculations. On the beginning of the operations, it showed 100% removal of hydrogen sulfide gas without lag phase. At SV of 50 $h^{-1}$, hydrogen sulfide gas from the outlet of the biofilter was not detected, when inlet concentration increased to 450 ppmv. After that, removal efficiency decreased as increasing inlet hydrogen sulfide concentration. Hydrogen sulfide removal was maintained at almost 93% until inlet concentration was increased up to 950 ppmv, at which the elimination capacity of $H_2S$ was 61.2 g $S{\cdot}m^{-3}{\cdot}h^{-1}$. Maximum elimination capacity guaranteing 90% removal was 61.2, 65.9, 84.7, 89.4 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV ranging from 50 $h^{-1}$ to 300 $h^{-1}$, but was 59.3 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV of 400 $h^{-1}$. The results calculated from Michaelis-Menten equation revealed that $V_m$ increased from 66.04, 88.96, 117.35, 224.15, to 227.54 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ with increasing space velocity in the range of 50 $h^{-1}$ to 400 $h^{-1}$. However, saturation constant$(K_s)$ decreased from 79.97 ppmv to 64.95 and 65.37 ppmv, and then increased to 127.72 and 157.43 ppmv.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.1
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• pp.15-26
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• 2017

Cobalt ferrocyanide (CoFC) or nickel ferrocyanide (NiFC) magnetic nanoparticles (MNPs) were fabricated for efficient removal of radioactive cesium, followed by rapid magnetic separation of the absorbent from contaminated water. The $Fe_3O_4$ nanoparticles, synthesized using a co-precipitation method, were coated with succinic acid (SA) to immobilize the Co or Ni ions through metal coordination to carboxyl groups in the SA. CoFC or NiFC was subsequently formed on the surfaces of the MNPs as Co or Ni ions coordinated with the hexacyanoferrate ions. The CoFC-MNPs and NiFC-MNPs possess good saturation magnetization values ($43.2emu{\cdot}g^{-1}$ for the CoFC-MNPs, and $47.7emu{\cdot}g^{-1}$ for the NiFC-MNPs). The fabricated CoFC-MNPs and NiFC-MNPs were characterized by XRD, FT-IR, TEM, and DLS. The adsorption capability of the CoFC-MNPs and NiFC-MNPs in removing cesium ions from water was also investigated. Batch experiments revealed that the maximum adsorption capacity values were $15.63mg{\cdot}g^{-1}$ (CoFC-MNPs) and $12.11mg{\cdot}g^{-1}$ (NiFC-MNPs). Langmuir/Freundlich adsorption isotherm equations were used to fit the experimental data and evaluate the adsorption process. The CoFC-MNPs and NiFC-MNPs exhibited a removal efficiency exceeding 99.09% for radioactive cesium from $^{137}Cs$ solution ($18-21Bq{\cdot}g^{-1}$). The adsorbent selectively adsorbed $^{137}Cs$, even in the presence of competing cations.

• The Journal of Engineering Geology
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• v.25 no.1
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• pp.93-102
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• 2015

The characteristics of frozen soils are one of most important factors for foundation design in cold region. The objective of this study is to evaluate the shear strength and stiffness of frozen soils according to the confining conditions during the freezing and shearing phase. A direct shear box is constructed for the frozen specimens and bender elements are mounted on the wall of the shear box to measure shear wave velocities. Specimens are prepared by mixing sand and silt with a silt fraction of 30% in weight and the degree of saturation of 10%, giving a relative density of 60% for all tests. The temperature of the specimens in the freezer is allowed to fall below -5℃, and then direct shear tests are performed. A series of vertical stresses are applied during the freezing and shearing phase. Shear stress, vertical displacement, and shear wave along the horizontal displacement are measured. Experimental results show that in all the tests, shear strength increases with increasing vertical stress applied during the freezing and shearing phases. The magnitude of the increase in shear strength with increasing vertical stress during shearing under fixed vertical stress in the frozen state is smaller than the magnitude of the increase in vertical stress during freezing and shearing. In addition, the change in shear wave velocities varies with the position of the bender elements. In the case of shear waves passing through the shear plane, the shear wave velocities decrease with increasing horizontal displacement. This study provides an evaluation of the properties of shear strength and stiffness of frozen soils under varied confining condition.