• Journal of the Korea Institute of Building Construction
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• v.7 no.4
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• pp.145-151
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• 2007

In this paper, tests are carried out in order to investigate the strength development of concrete under various binder types, W/B and curing temperature ranged from $5{\sim}20^{\circ}C$. Fly ash and blast furnace slag were incorporated by as much as 30%, respectively. Strength development of concrete are estimated using Logistic model and strength ratio of concrete at 28days to that at early age are also investigated. According to experimental results, it is found that good agreements are obtained between measured values and calculated ones using logistic model below $20^{\circ}C$. Strength ratio of concrete at 28days to that at early age increases in case W/B decreases and curing temperature increases. Tables and graphs for strength ratio of concrete are provided in this paper. It is capable of obtaining and predicting the periods to attain design strength by considering increment factor of strength easily with the table and graphs presented in this paper. This paper presents the reference data to decide removal time of form, time to reach target strength and strength inspection of remicon whether the test specimens meet the specified criteria of compressive strength. Multi regression models with respect to the relationship between 7days compressive strength and 28 days compressive strength depending on W/B and admixture types are presented.

• Journal of the Korean Wood Science and Technology
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• v.24 no.4
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• pp.15-21
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• 1996

This study was carried out to investigate the making method and properties of Hanji(Korean traditional paper) for wallpaper for the purpose of mass production and mass consumption of Hanji. Paper mulberry fiber was longer than wood fiber in length and it had also much extractives and ash in content. Bast fiber was a little damaged in the fibrilation and beating process because it was weak in flexibility and compressive properties. Proper conditions for making two-ply and three-ply Hanji were examined and six kinds of Hanji were made on the basis of the three-ply paper making method. The sample OH(Original Hanji) 2-2 and OH 3-2 among them obtained good results in quality test by appearance from wallpaper makers.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.279-284
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• 2006

Activated carbon is proposed as a new application of wastepaper recycling other than the paper-making. Waste kraft bag is considered to be a suitable raw material for activated carbon because of its low ash content. Small pellets of wastepaper squeezed out from the continuous kneader were carbonized in a nitrogen atmosphere and activated using carbon dioxide. The BET specific surface areas of activated carbon prepared from waste kraft bag was $1,285m^{2}/g$, which is higher than commercially available activated carbons. The activated carbon prepared from wastepaper has a well-developed porous structure, particularly in mesopore and macropore ranges. As a result, activated carbon with iodine adsorption capacity of 1,400 mg/g was obtained from waste kraft bag. In this paper, adsorption amount of Bisphenol A (BPA) was determined to investigate adsorbability of activated carbon from waste kraft bag. Adsorption measurements were on solutions ranging from $0.1{mu}g/L\;to\;100mg/L$. The activated carbon from waste kraft bag gave higher BPA adsorbabilities over a wide range, compared with commercially available activated carbons.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.6
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• pp.678-684
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• 1996

Seed pelleting have successfully been used in many crops for better crop estab-lishment and for mechanizing seeding process for small crop seeds in developed countries. In this experiment various pelleting materials and binders were tested to get basic information on the shape, hardness and germination of pelleted seesds of cabbage (cv. Seoul Beachoo) and rice (cv: Ilpoom). PLL-11, paper clay, lime and coal ash were good materials to make smooth shape of the pellets with pel gel and AG-11 as binders, and PLL-ll as material and pelgel and AG-11 as binders were the best among them in consideration of shape and hardness together. The hardness of the pelleted seeds were differed with each other depending on both of the pelleting materials and binders. Pelleted cabbage seeds coated by pelgel as binder with different materials showed lower germination percentge than control in general, but the seeds pelleted by PLL-11 with different binders showed no restraint effects. When the cabbage seed pelleted by PLL-11 with pelgel as binder showed almost same germination percentage as control. The pH and electrical conductivity of the extract from bentonite and zeolite were very higher than other materials tested and germination percentage showed a little lower than control when the cab-bage seed planted on the filter paper damped with the extract. As a result, PLL-11 as pelleting material and pel gel and AG-11 as binder appeared the good materials to make pellets of cabbage seeds and rice in consideration of shape, hardness and germination.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.4
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• pp.61-67
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• 2007

Paper sludges collected from three different paper mills were physico-chemically analyzed in order to use them as raw materials for making bed soils and seedling pots. The sludge from a fine paper mill contained lots of inorganic pigment particles used for coating, as those from a newsprint mill and a tissue mill had not. It was clearly through XRD analysis confirmed that all sludges included calcium carbonate. The paper sludge from the tissue mill contained the greatest amount of particles, which would contribute to water absorption and nutrient storage. The sludge from the fine paper mill had the highest density due to many inorganic elements. While the ash content and the total nitrogen content were the highest in the sludge from the fine paper mill, the C/N ratio was the lowest in the fine paper mill sludge. All sludges seemed to have insufficient contents of potassium. The sludges from the newsprint mill and the tissue mill showed more silicon contents than that from the fine paper mill. It was concluded that the sludge from the fine paper mill would be able to be the most efficient raw materials for making bed soils and seedling pots and the other two sludges would be more efficient for intensive culture for crops such as rice and grain with additional supplement of nitrogen and other nutrients.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1510-1510
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• 2001

NIRS uses reflectance signals resulting from bending and stretching vibrations in chemical bonds between carbon, nitrogen, hydrogen, sulfur and oxygen. These reflectance signals are used to measure the concentration of major chemical composition and other descriptors of homogenized and freeze-dried whole broiler carcasses. Six strains of chicken were analyzed and the NIRS model predictions compared to reference data. The results of this comparison indicate that NIRS is a rapid tool for predicting dry matter (DM), fat, crude protein (CP) and ash content in the broiler carcass. Males and females of six commercial strain crosses of broiler chicken (Gallus domesticus) were used in this study (6$\times$2 factorial design). Each strain was grown to 16 weeks of age, and duplicate serial samples were taken for body composition analysis. Each whole carcass was pressure-cooked, homogenized, and a representative sample was freeze-dried. Body composition determined as follows: DM by oven dried method at 105$^{\circ}C$ for 3 hours, fat by Mojonnier diethyl ether extraction, CP by measuring nitrogen content using an auto-analyzer with Kjeldhal digest and ash by combustion in a muffle furnace for 24 hour at 55$0^{\circ}C$. These homogenized and freeze-dried carcass samples were then scanned with a Foss NIR Systems 6500 visible-NIR spectrophotometer (400-2500nm) (Foss NIR Systems, Silver Spring, MD., US) using Infra-Soft-International, ISI, WinISl software (ISI, Port Matilda, US). The NIRS spectra were analyzed using principal component (PC) analysis. This data was corrected for scatter using standard normal “Variate” and “Detrend” technique. The accuracy of the NIRS calibration equations developed using Partial Least Squares (PLS) for predicting major chemical composition and carcass descriptors- such as body mass (BM), bird dry matter and moisture content was tested using cross validation. Discrimination analysis was also used for sex and strain identification. According to Dr John Shenk, the creator of the ISI software, the calibration equations with the correlation coefficient, $R^2$, between reference data and NIRS predicted results of above 0.90 is excellent and between 0.70 to 0.89 is a good quantifying guideline. The excellent calibration equations for DM ($R^2$= 0.99), fat (0.98) and CP (0.92) and a good quantifying guideline equation for ash (0.80) were developed in this study. The results of cross validation statistics for carcass descriptors, body composition using reference methods, inter-correlation between carcass descriptors and NIRS calibration, and the results of discrimination analysis for sex and strain identification will also be presented in the poster. The NIRS predicted daily gain and calculated daily gain from this experiment, and true daily gain (using data from another experiment with closely related broiler chicken from each of the six strains) will also be discussed in the paper.

• Microbiology and Biotechnology Letters
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• v.2 no.2
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• pp.83-88
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• 1974

The water pollution by waste water is one of the important issue and the short of animal feed is too, in Korea. So, this experiment is accomplished to treat alcohol distillers' waste by micro-organisms and planning to produce yeasts, which can be used as animal feed, pharmacy and condiments. 1. The raw material, alcohol distillers' waste, of this experiment consists of insoluble solids (residue) and filterate (supernatant). The residue contains 33.08％ of crude protein, 19.96％ of total sugar. and 2.06％ of ash, respectively. On the other hand the flterate through the Toyo filter paper No. 5C, contains 2.48％ of crude protein, 1.54％ of reducing sugar, and 0.43％ of ash, respectively. 2. Optimum pH of the basal medium for the growth of Saccharomyces cerevisiae YF-1 is 4.0. Optimum culture condition of this is as follows : when 0.43g of urea, 0.43g of potassium phosphate monobasic, and 0.21g of magnesium sulfate are added to the 100m1 of basal medium. Optimum temperature and optimum incubation time are 30$^{\circ}C$ and 24-28 hrs. 3. Under these conditions, the maximum yield of dry yeast is 1.38％ to the medium. 4. The composition of dry yeast, produced under these conditions, is as follows: crude protein, 56.96％, lipid, 1.30％. total sugar, 6.53％, and ash 9.62％.

• Journal of the Korea Concrete Institute
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• v.18 no.6 s.96
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• pp.759-767
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• 2006

This paper presents a method to estimate the setting time of concrete using super retarding agent(SRA) and fly ash(FA) under various curing temperature conditions by applying maturity based on equivalent age. To estimate setting time, the equivalent age using apparent activation energy($E_a$) was applied. Increasing SRA content and decreasing curing temperature leads to retard initial and final set markedly. $E_a$ at the initial set and final set obtained by Arrhenius function showed differences in response to mixture type. It is estimated to be from $24{\sim}35KJ/mol$ in all mixtures, which is smaller than that of conventional mixture ranging from $30{\sim}50KJ/mol$. Based on the application of $E_a$ to Freisleben-Hansen and Pederson's equivalent age function, equivalent age is nearly constant, regardless of curing temperature and SRA contents. This implies that the concept of maturity is applicable in estimating the setting time of concrete containing SRA. A high correlation between estimated setting time and measured setting time is observed. Multi-regression model to determine appropriate dosage of SRA reflecting FA contents and equivalent age was provided. Thus, the setting time estimation method studied herein can be applicable to the concrete containing SRA and FA in construction fields.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.499-504
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• 2005

Polymer concrete shows excellent mechanical properties and chemical resistance compared with conventional normal cement concrete. The polymer concrete Is drawing a strong interest as high-performance materials in the construction industry Resins using recycled PET offer the possibility of a lower source cost of materials for making useful polymer concrete products. Also the recycling of PET in polymer concrete would help solve some of the solid waste problems Posed by plastics and save energy. An objective of this paper is to estimate the damage of sulfuric acid, through investigating recycled PET polymer concrete, immersed at sulfuric acid solution for 84 days. As a result of testing, recycled PET PC, used $CaCO_3$ as filler, makes a problem of appearance and strength if they are exposed for long term at corrosion environment. On the other hand, recycled PET PC, used fly-ash as filler, had less effect on decrease in weight and strength. Recycled PET PC is excellent chemical resistance, resulting in the role of unsaturated polyester resin which consists of polymer chain structure accomplishes bond of aggregates and filler strongly. Also, recycled PET PC, used fly-ash as filler, is stronger resistance of sulfuric acid corrosion than $CaCO_3$, because it is composed of $SiO_2$ and very strong glassy crystal structure. Therefore, recycled PET PC, used fly-ash as filler, is available under corrosion circumstances like sewer pipe or waste disposal plant.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.1
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• pp.1-7
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• 2014

This paper aims to explain the safety assessment and remediation mechanism of Granulated Coal Ash (GCA) as a material for the remediation of coastal sediments and to evaluate the improvement of the sediment in Kaita Bay, where GCA was applied. The concentrations of heavy metal contained in GCA and the dissolved amounts of heavy metal from GCA satisfied the criteria for soil and water pollution in Japan. The mechanisms on the remediation of coastal sediments using GCA is summarized as follows; (1) removal of phosphate and hydrogen sulfide (2) neutralization of acidic sediment (3) oxidation of reductive sediment (4) increase of water permeability (5) increase of soil strength (6) material for a base of seagrass. From the results obtained from the field experiment carried out in Kaita Bay, it was clarified that GCA is a promizing material for remediation of coastal sediment. This remediation technology can contribute to promote waste reduction in society and to decrease cost of coastal sediment remediation by applying GCA in other polluted coastal areas.