• Korean Journal of Agricultural Science
• /
• v.23 no.1
• /
• pp.39-50
• /
• 1996

The normal cement concrete is widely used material to build the construction recently, but it has a fault to increase the dead load on account of its unit weight is large compared with strength. So, many engineers are continuously searching for new materials of construction to provide greater performance at lower density. Many studies were carried out on the lightweight aggregate concrete in foreign country in the latter half of the 19th century, therefore lightweight aggregate concrete has been used successfully for many years for structural members. The main purpose of the work described in this paper were to establish its physical and mechanical properties of no-fines lightweight concrete using synthetic lightweight coarse aggregates. Test results are summarized as follows ; The water-cement ratio was shown less than 33% in use synthetic lightweight coarse aggregates, unit weights of synthetic lightweight concrete was shown less than $1,800kg/m^3$ and compressive strength was higher than $200kg/m^2$. And the pulse velocity was more than 3,000m/sec. The relationship of compressive strength between unit weight and pulse velocity was shown to be approximately linear.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2006.06a
• /
• pp.141-151
• /
• 2006

A blank test was done to calculatee the car itself's magnetic effect as noise and to eliminate it from the data set of total magnetic intensity(=magnetic flux density) exploration in a car-borne magnetic exploration system. To calculate the induced magnetic intensity(= magnetization) and the remanent magnetic intensity(= magnetization) of the car itself, we have installed the magnetometer on a fixed point and measured the magnetic intensity letting the car move around the magnetometer, and we have changed the data set into an analogous data set as if acquired in the condition that we have parked the car on the same fixed point and measured the magnetic intensity moving the magnetometer around the magnetometer. Through an inversion with the later data set as input, we have calculated the magnetic center and the magnetic moments of the induced magnetic intensity(= magnetization) and the remanent magnetic intensity(= magnetization) of the car itself with the two centers coincided because of some barriers of the inversion algorithm that we have used in this study. On the other hand, we have extracted the magnetic anomaly by reducing i. e. vectorially eliminating the induced magnetic intensity(= magnetization) and the remanent magnetic intensity(= magnetization) of the car itself calculated forwardly, from the magnetic exploration data set acquired by the car-borne magnetic exploration system.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.30 no.2 s.150
• /
• pp.275-285
• /
• 2006

The purpose of this study was to examine the change of dyeing ability by K/S values, when dyed in different twisting processes and by one bath system and two bath system, to find possible ways of minimizing the color difference between cotton and polyester in composite yarn. The two types of composite yarn, which had one setting process(CP1) and two setting processes(CP2) were dyed with reactive/disperse dyes in both one bath dyeing system and two bath system. The dyeing ability according to the two different twisting processes was measured, and the values of the CP1 were higher compare to the values of CP2 in both one and two bath dyeing systems. This is because CP1 applied only one setting could shrink dyeing process at 130$^{circ}C$. This shrinkage increased the number of twists in the unit length and increased the yarn density, and this is the reason that the K/S values were measured higher than those of CP2. In wet shrinkage test, in opposition to CP2 only had 0.76$\%$ of the shrinkage rate, CP1 had 3.00$\%$ of the shrinkage rate. Also, the dyeing ability according to the two different dyeing methods was measured, and the values of CP1 and CP2 were both higher when dyed in two bath system. On the other hand, the color differences between cotton and polyester in composite yarns, were smaller for CP2 than that for CP1 and were also smaller in two bath dyeing system than in one bath dyeing system. Therefore, the ways of minimizing color difference between cotton and polyester in composite yarn are to apply enough setting in order to minimize shrinkage in dyeing process and to choose two bath dyeing system.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.206-206
• /
• 2017

Sorghum is a crop with a various plant height depending on the planting density. If the height exceeds 1.8m, which is the harvestable height of the combine, loss is caused by clogging of the installation, entrance of the threshing section and the threshing section. The purpose of this study is to set the planting distance and number of plants per hill suitable for combine harvesting as the plant length does not exceed 1.8m. The experimental variety was Nampungchal. The experiment design was a split-plot design with three replications. The treatments were as follow: Main-plot were 1 and 2 plants as number of plants per hill and sub-plots were $60{\times}20cm$ (practice), $70{\times}15$, 20, 25, 30 cm as planting distance. The amount of nitrogen, phosphate and potassium fertilization were 100, 70, $80kg\;ha^{-1}$. Data were collected: (1) grain yield: weight of grain in $kg\;ha^{-1}$, (2) 1000 grain weight: average weight of 1000 grain, (3) plant height: distance from soil to top of panicle, (4) ear length: distance from top of stem to top of ear in cm, (5) stem diameter: diameter of second internode, (6) tiller number per hill. Analyses of variance were performed using R version 3.3.1(https://www. r- project. org). The Duncan's multiple range test(DMR) was used to separate treatment means at P < 0.05. As number of plants per hill increased, plant height and yield increased and tiller number decreased. As planting distance increased, plant height and yield decreased and tiller number increased. At 1 plant per hill, the plant height did not exceed 1.8m at all planting distance. At 2 plants per hill, the plant height did not exceed 1.8m from the planting distance of $70{\times}25cm$. At 1 plant per hill, the tiller number increased to 0.23, 0.27, 0.60 and 0.70 as the planting distance increased to $70{\times}15$, 20, 25 and 30 cm, respectively. At 2 plants per hill, the tiller number increased to 0.03, 0.03, 0.14 and 0.40 as the planting distance increased to $70{\times}15$, 20, 25 and 30 cm, respectively. At 1 plant per hill, the yield decreased to 6030, 4280, 3400 and $3230kg\;ha^{-1}$ as the planting distance increased. At 2 plant per hill, the yield decreased to 7850, 5770, 5720 and $4960kg\;ha^{-1}$ as the planting distance increased. We recommend that the optimum number of plants per hill and planting distance is 2 and $70{\times}25cm$ suitable for combine harvesting.

• Korean Journal of Pharmacognosy
• /
• v.47 no.2
• /
• pp.158-164
• /
• 2016

This study was conducted to verify the potential of Allium hookeri to control blood glucose metabolism in diabetes model. We fed the experimental diets(ALE, ARE) supplemented with the extract of Allium hookeri leaf or root at 1% of diet to the diabetic mice (C57BLKS/J, db/db) for 8 weeks. Hetero and control mice were fed the control diet without any extract of Allium hookeri leaf or root. At 8th week of feeding the diets, we measured body weight, blood glucose, HbA1c, and plasma insulin levels and conducted an oral glucose tolerance test (OGTT) and staining insulin immunoreactive cells in islets of pancreas. ARE group treated with the root of A. hookeri showed significantly lower blood glucose levels than the Cont group at 120 min in the OGTT. However, HbA1c level was significantly reduced in both ALE and ARE groups, and higher serum insulin levels and increased density of insulin immunoreactive cells compared with the Cont group were found in these 2 groups. Based on these results, A. hookeri is considered to be effective in improving glucose tolerance by partially affecting insulin secretion and it may be used to prevent and treat diabetic disease.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.32 no.4
• /
• pp.393-400
• /
• 2012

In recent years, nano-structured thin film systems are often applied in industries such as MEMS/NEMS device, optical coating, semiconductor or like this. Thin films are used for many and varied purpose to provide resistance to abrasion, erosion, corrosion, or high temperature oxidation and also to provide special magnetic or dielectric properties. Quite a number of articles to evaluate the characterization of thin film structure such as film density, film grain size, film elastic properties, and film/substrate interface condition were reported. Among them, the evaluation of film adhesive to substrate has been of great interest. In this study, we fabricated the polymeric thin film system with different adhesive conditions to evaluate the adhesive condition of the thin film. The nano-structured thin film system was fabricated by spin coating method. And then V(z) curve technique was applied to evaluate adhesive condition of the interface by measuring the surface acoustic wave(SAW) velocity by scanning acoustic microscope(SAM). Furthermore, a nano-scratch technique was applied to the systems to obtain correlations between the velocity of the SAW propagating within the system including the interface and the shear adhesive force. The results show a good correlation between the SAW velocities measured by acoustic spectroscope and the critical load measured by the nano-scratch test. Consequently, V(z) curve method showed potentials for characterizing the adhesive conditions at the interface by acoustic microscope.

• Parasites, Hosts and Diseases
• /
• v.53 no.1
• /
• pp.35-41
• /
• 2015

Pyronaridine and artesunate have been shown to be effective in falciparum malaria treatment. However, pyronaridine is rarely used in Hainan Island clinically, and artesunate is not widely used as a therapeutic agent. Instead, conventional antimalarial drugs, chloroquine and piperaquine, are used, explaining the emergence of chloroquine-resistant Plasmodium falciparum. In this article, we investigated the sensitivity of P. falciparum to antimalarial drugs used in Hainan Island for rational drug therapy. We performed in vivo (28 days) and in vitro tests to determine the sensitivity of P. falciparum to antimalarial drugs. Total 46 patients with falciparum malaria were treated with dihydroartemisinin/piperaquine phosphate (DUO-COTECXIN) and followed up for 28 day. The cure rate was 97.8%. The mean fever clearance time ($22.5{\pm}10.6hr$) and the mean parasite clearance time ($27.3{\pm}12.2hr$) showed no statistical significance with different genders, ages, temperatures, or parasite density (P>0.05). The resistance rates of chloroquine, piperaquine, pyronarididine, and artesunate detected in vitro were 71.9%, 40.6%, 12.5%, and 0%, respectively (P<0.0001). The resistance intensities decreased as follows: chloroquine>piperaquine>pyronarididine>artesunate. The inhibitory dose 50 ($IC_{50}$) was $3.77{\times}10^{-6}mol/L$, $2.09{\times}10^{-6}mol/L$, $0.09{\times}10^{-6}mol/L$, and $0.05{\times}10^{-6}mol/L$, and the mean concentrations for complete inhibition (CIMC) of schizont formation were $5.60{\times}10^{-6}mol/L$, $9.26{\times}10^{-6}mol/L$, $0.55{\times}10^{-6}mol/L$, and $0.07{\times}10^{-6}mol/L$, respectively. Dihydroartemisinin showed a strong therapeutic effect against falciparum malaria with a low toxicity.

• Journal of the Korean Wood Science and Technology
• /
• v.40 no.6
• /
• pp.406-417
• /
• 2012

In this study, eco-friendly hybrid composite boards were manufactured from green tea, three kinds of charcoals and wood fiber for developing interior materials to reinforce the functionalities such as the deodorization and the absorbability on the green tea-wood fiber hybrid boards in the previous researches. The effects of kind of raw materials and the component ratio of raw materials on dimensional stability, deodorization and emission of formaldehyde were investigated. Thickness swelling of the hybrid composite boards increased with increasing of component ratio of green tea and charcoals, but the values were markedly lower than that of Korean standard (KS) for commercial medium density fiber board (MDF), except for hybrid composite boards composed of greed tea, activated charcoal and wood fiber. Reduction rate of ammonia gas for the hybrid composite boards composed of green tea, activated charcoal and wood fiber showed a high value of 96% after 30 minute from the beginning of the test, and the other hybrid boards also showed a high value of about 95% after one hour. Emission amount of formaldehyde was similar to that of $E_0$ grade in case of using $E_1$ grade urea resin, and was similar to that of super $E_0$ grade in case of using $E_0$ grade urea resin.

• Food Science of Animal Resources
• /
• v.27 no.3
• /
• pp.337-344
• /
• 2007

We have investigated the relationship between food allergen sensitization and allergic disease in 74 child (male 47, female 27) patients from 0 to 14 years of age diagnosed with allergic disease. The age distribution for the study was: newborn to 3 years old, 34 children; 4 to 6 years old, 24 children; 7 to 9 years old, 8 children and above 10 years old, 8 children. Of the 74 children, 10 children were allergic to 3 of the 21 types of foods tested, 21 children were allergic to 4 types and 15 children were allergic to 5 types. The results of specific IgE tests for class 2 (0.070-3.49 IV/mL, IgE density in serum) showed that 29 children were allergic to milk, 28 children to bean, 21 children to cheese, 7 children to egg, and 18 children to pork, while over class 2, 20 children were allergic to bean, 17 children to milk, 24 children to cheese, 20 children to egg, and 21 children to pork. A questionnaire was used to survey family allergy history and diet patterns for 40 child (male 22, female 18) patients with allergic disease. The frequencies of a family history of allergy were 45.5% for males and 50.0% for females. The allergic diseases included atopic dermatitis: 26.0%, atopic nasitis: 10.5%, atopic dermatitis + atopic nasitis : 31.5%, hives: 21.0%, and asthma: 10.5%. Children on diets of mixed breast feeding and infant formula were more allergic than those on either breast feeding or infant formula feeding. Eliminated allergenic foods were egg + milk: 12.5%, egg: 10.0%, and milk 2.5%.

• Journal of the Korean Geotechnical Society
• /
• v.34 no.9
• /
• pp.5-17
• /
• 2018

A magnitude 5.4 earthquake struck the city of Pohang, North Gyeongsang Province, South Korea on November 15, 2017. Many sand volcanoes were observed on paddy fields, parks and roads. This phenomenon was the first to be observed as a sign of soil liquefaction in South Korea. In this study, two different kinds of ejected Pohang sands were collected from a liquefied paddy field. Those sands were reconstituted into loose and dense conditions and then a series of cyclic simple shear tests were conducted under confining stresses of 100 and 200 kPa. A real earthquake motion was also repetitively applied to the specimen. As a result of constant shear stress tests, the cyclic resistance ratio (CRR) of loose sand was 0.12-0.14, while the CRR value of dense sand was 0.17-0.21. It was shown that the relative density was more influencing factor on liquefaction resistance than the sand types and initial confining stress. When a real Pohang earthquake motion was repetitively applied to the specimen, a loose sand was liquefied at the second earthquake motion but the dense sand at the third earthquake motion.