• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.71-77
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• 2013

The world demand of renewable bioenergy as an alternative transportation fuel is greatly increasing. Research for bioethanol production is currently being progressed intensively throughout the world. Therefore it will be necessary to develop bioethanol production with cellulosic materials. In this study, the yield of ethanol production was evaluated by simultaneous saccharification and fermentation (SSF) using sodium hydroxide pretreated sorghum ${\times}$ sudangrass hybrids. Composition analysis of 11 varieties of sorghum ${\times}$ sudangrass hybrids was performed for selection of excellent variety to efficiently produce bioethanol. The content of cellulose, hemicellulose, lignin and ash of these varieties were 32~39%, 19~24%, 17~22% and 6~11%, respectively. Among these varieties, 4 varieties of sorghum ${\times}$ sudangrass hybrids were selected for the evaluation of ethanol yield and those were pretreated with 1 M NaOH solution at $150^{\circ}C$ for 30 min using high temperature explosion system. After pretreatment, samples were neutralized with tap water. It contained 52~57% of cellulose. Simultaneous saccharification and fermentation (SSF) was carried out for 48 h at $33^{\circ}C$ by Saccharomyces cerevisiae CHY1011 using Green star variety. The yield of ethanol was 92.4% and the amount of ethanol production was estimated at 6206 L/ha.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.2
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• pp.94-101
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• 2016

This paper presents an investigation into the durability alkali-activated materials(AAM) mortar and paste samples manufactured using fly-ash(FA) and ground granulated blast furnace slag(GGBFS) exposed to a sulfate environment with different GGBFS replace ratios(0, 30, 50 and 100%), sodium silicate modules($Ms[SiO_2/Na_2O]$ 1.0, 1.5 and 2.0) and initial curing temperatures($23^{\circ}C$ and $70^{\circ}C$). The tests involved immersions for a period of 6 months into 10% solutions of sodium sulfate and magnesium sulfate. The evolution of compressive strength, weight, length expansion and microstructural observation such as x-ray diffraction were studied. As a results, as higher GGBFS replace ratio or Ms shown higher compressive strengths on 28 days. In case of immersed in 10% sodium sulfate solution, the samples shows increase in long-term strength. However, for samples immersed in magnesium sulfate solutions, the general observation was that the compressive strength decreased after immersion. The most drastic reduction of compressive strength and expansion of weight and length occurred when GGBFS or Ms ratios were higher. Also, the XRD analysis of samples immersed in magnesium sulfate indicated that expansion of AAM caused by gypsum($CaSO_4{\cdot}2H_2O$); the gypsum increased up to 6 months continuously.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.267-275
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• 2007

Melting slag generated from municipal-incinerator ash contains lots of impurities which have adverse effects on zeolite synthesis. These impurities are detrimental to zeolite synthesis, and the yield and purity of zeolite was decreased. And thus its performance is lowered. In melting slag, there are lots of components such as $Fe_2O_3$, FeO and CaO. To remove these impurities, we treated the melting slag with hydrochloric acid at initial pH 1, 3, 5, and 7. After the treatment, the $SiO_2,\;Fe_2O_3,\;and\;TiO_2$ ratios increased, but the $Al_2O_3,\;FeO,\;CaO,\;Na_2O$ and MgO ratios decreased. We reacted these treated slag in a NaOH solution under hydrothermal conditions at $80^{\circ}C$. The hydrothermal products from the slag and the slag treated at pH 7 and pH 5 were determined to be tobermorite, whereas those at pH 3 and pH 1, Na-P1 and Na-X zoelite respectively. CaO was found to inhibit the synthesis of zeolite.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.382-386
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• 1983

In order to utilize effectively sea mustard(Undaria pinnatifida) which is excellent in nutrition and medical action, powdered sea mustard juice was prepared and then its chemical composition and the stability of pigments were examined. Powdered sea mustard was made by washing fresh sea mustard with tap water to remove clay and sand, blanching at $85^{\circ}C$ for 20 sec in mixing solution(3% salt+1% $MgCO_3$), hot air drying($50-55^{\circ}C$, 3 hrs) after draining and pulverizing dried sea mustard to 200mesh. And then powdered sea mustard mixtures for juice type beverage was made by adding 0.75% of salt, 1.25% of sugar, 0.2% of ascorbic acid, 0.25% of flour of roasted barley and 0.8% of pulverized sea mustard to 100ml of water. Chemical composition of product was not scarcely changed during processing while amino-nitrogen content was increased and alginic acid and ash contents were decreased. The retention of chlorophyll and total carotenoid pigments of product against fresh sea mustard were 91.6% and 89.5% respectively. Judging from sensory evaluation, color, flavor, taste and dispersibility of powdered sea mustard juice were excellent and undesirable flavor of product was masked by addition of flour of roasted barley.

• Food Science and Preservation
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• v.15 no.5
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• pp.719-724
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• 2008

The overall objectives of this study were to examine the potential of sturgeon as an intermediate moisture food (IMF) by measurement of nutritional components, such as minerals, fatty acids, amino acids, and water activity. Chemical compositions were as follows:moisture 73.2%, crude protein 19.9%, crude lipid 5.7%, ash 1.1%, and carbohydrate 0.1%. Minerals were K 317.70, P 259.88, and Mg 29.78 mg/100 g. Fatty acids detected were oleic acid (40.46% of total), palmitic acid (23.27%), and linoleic acid (15.35%). In addition, sturgeon was very rich in glutamic acid (1,189.71 mg/100 g) and deficient in serine (55.12 mg/100 g). Moisture content and water activity of sturgeon dried at $40^{\circ}C$ after soaking in different concentrationsof sugar and salt solutions were 15.12-16.24% and 0.68-0.79, respectively. Sensory evaluation of sturgeon soaked in different concentrations of sugar and salt solutions indicated that sturgeon soaked in 3.0% (w/v) sugar and salt solution scored highest.

• Clean Technology
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• v.16 no.2
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• pp.117-123
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• 2010

In this study, we propose two methods able to recover different type of gold from gold-cyanide solutions: biosorption and desorption process for mono-valent gold recovery and biosorption and incineration process for zero-valent gold recovery. The waste bacterial biomass of Corynebacterium glutamicum generated from amino acid fermentation industry was used as a biosorbent. The pH edge experiments indicated that the optimal pH range was pH 2 - 3. From isothermal experiment and its fitting with Langmuir equation, the maximum uptake capacity of Au(I) at pH 2.5 were determined to be 35.15 mg/g. Kinetic tests evidenced that the process is very fast so that biosorption equilibrium was completed within the 60 min. To recover Au(I), the gold ions were able to be successfully eluted from the Au-loaded biosorbent by changing the pH to pH 7 and the desorption efficiency was 91%. This indicates that the combined process of biosorption and desorption would be effective for the recovery of Au(I). In order to recover zero-valent gold, the Au-loaded biosorbents were incinerated. The content of zero-valent gold in the incineration ash was as high as 85%. Therefore, we claim on the basis of the results that two suggested combined processes could be useful to recover gold from cyanide solutions and chosen according to the type of gold to be recovered.

• Korean Journal of Hazardous Materials
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• v.2 no.1
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• pp.18-26
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• 2014

We analyzed the demand of competent authorities requiring adequate technical information for initial investigation of chemical accidents. Reflecting technical reports on chemical accident response by environmental agencies in the U.S. and Canada, we presented information on environmental diffusion and toxic effects available for the first chemical accident response. Hydrogen fluoride may have the risk potential to corrode metals and cause serious burns and eye damages. In case of inhalation or intake, it could have severe health effects. The substance itself is inflammable, but once heated, it decomposes producing corrosive and toxic fume. In case of contact with water, it can produce toxic, corrosive, flammable or explosive gases and its solution, a strong acid, may react fiercely with a base. In case of hydrogen fluoride leak, the preventive measures are to decrease steam generation in exposed sites, prevent the transfer of vapor cloud and promptly respond using inflammable substances including calcium carbonate, sodium bicarbonate, ground limestone, dried soil, dry sand, vermiculite, fly ash and powder cement. The method for fire fighting is to suppress fire with manless hose stanchions or monitor nozzles by wearing the whole body protective clothing equipped with over-pressure self-contained breathing apparatus from distance. In case of transport accident accompanied with fire, evacuation distance is 1,600m radius. In cae of fire, fire suppression needs to be performed using dry chemicals, CO₂, water spray, water fog, and alcohol-resistance foam, etc. The major symptoms by exposure route are dyspnoea, bronchitis, chemical pneumonia and pulmonary edema for respiration, skin laceration, dermatitis, burn, frostbite and erythema for eyes, and nausea, diarrhea, stomachache, and tissue destruction for digestive organs. In atmosphere, its persistency is low, and its bioaccumulation in aquatic organism is also low.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.37-46
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• 2024

This study investigates the evolution of concrete damage due to chloride-induced steel corrosion through Impact-echo (IE) testing. Three reinforced concrete specimens, each measuring 1500 mm in length, 400 mm in width, and 200 mm in thickness, were fabricated using three concrete mixture proportions of blended cement types: ordinary Portland cement, ground granulated blast-furnace slag and fly ash. Steel corrosion in the concrete was accelerated by impressing a 0.5 A current following a 35-day cycle of wet-and-dry saturation in a 3% NaCl solution. Initial IE data collected during the saturation phase showed no significant changes, indicating that moisture had a minimal impact on IE signals and highlighting the slow progress of corrosion under natural conditions. Post-application of current, however, there was a noticeable decline in both IE peak frequency and the P-wave velocity in the concrete as the duration of the impressed current increased. Remarkably, progressive monitoring of IE proves highly effective in capturing the critical features of steel-corrosion induced concrete deterioration, such as the onset of internal damages and the rate of damage propagation. These results demonstrate the potential of progressive IE data monitoring to enhance the reliability of diagnosing and prognosticating the evolution of concrete damage in marine environment.

• Animal Bioscience
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• v.37 no.7
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• pp.1246-1254
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• 2024

Objective: The goal of the current study was to investigate the impact of various concentrations of xylanase in energy-deficient corn-based diets on the growth performance, carcass characteristics, nutrient digestibility, and digesta viscosity in broilers from 7 to 35 days of age. Methods: A total of 280 seven-day-old Ross 308 broilers were randomly allocated to one of the five dietary treatments following a completely randomized design with 8 replicates and 7 birds per cage. The treatments were: i) positive control (PC, without xylanase); ii) NC-1 (80 kcal/kg ME reduced from PC); iii) NC-2 (100 kcal/kg ME reduced from PC); iv) NCX-1 (NC-1 + 2,000 U/kg xylanase); and v) NCX-2 (NC-2 + 3,000 U/kg xylanase). Body weight, weight gain, feed intake, and feed conversion ratio were determined weekly to evaluate growth performance. One bird per pen was sacrificed for ileal digesta collection to determine the viscosity and digestibility of energy, dry matter, crude protein on days 24 and 35, however breast and leg meat samples were obtained for proximate analysis (moisture, crude protein, fat, and ash) on day 35. Results: Birds fed diets supplemented with xylanase regardless of the amount had higher (p<0.05) body weights, daily gains, and improved feed efficiency compared to NC diets all throughout the experimental period. Feed intake was not affected (p>0.05) by the addition of xylanase. Moreover, lowered (p<0.05) viscosity of the ileal digesta were observed upon xylanase inclusion in the diets compared to the birds fed NC diets on day 24. Ileal nutrient digestibility and meat proximate composition were not affected (p>0.05) by xylanase. Conclusion: The present study indicated that the xylanase at 2,000 U/kg and 3,000 U/kg levels compensates for the 80 kcal/kg and 100 kcal/kg dietary energy levels, respectively, without having adverse effects on the growth performance, carcass characteristics, nutrient digestibility, and digesta viscosity of broilers.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.95-103
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• 2016

The objective of this study was to investigate feasibility of semi-dry anaerobic digestion using dairy cattle manure and to evaluate solidified fuel value of semi-dry anaerobic digestate. To evaluate semi-dry anaerobic digestion using dairy cattle manure, 950 mL bottle type anaerobic reactor was set in the constant temperature room maintained at $35^{\circ}C$. To produce anaerobic digestate for making solidified fuel, acrylic cylindrical anaerobic digester(1,000 mm width ${\times}$ 450 mm height) was set in the constant room temperature to carry out batch test of semi-dry anaerobic digestion using same dairy cattle manure. Moisture content of dairy cattle manure and inoculum solution for anaerobic digestion were 80.64% and 96.83%, respectively. The dairy cattle manure and the inoculum solution was mixed by 1:1 ratio(v/v) for anaerobic digestion. Water content and VS/TS(Volatile Solids/Total Solids) of mixture of substrate and inoculum were 89.74% and 83.35%, respectively. In case of non-inoculated anaerobic digester, the biogas was not produced. By the semi-dry anaerobic digestion, the calorific value of the digestate was reduced by 20% compare to fresh dairy cattle manure. In other hand, ash content increased from 15% to 18.4%. The contents of Cr, Pb, Cd and S of pellet produced from anaerobically digested dairy cattle manure were not against the standard regulation for livestock manure solidified fuel. Therefore, it can be used as fuel that anaerobic digestate produced after semi-dry anaerobic digestion using dairy cattle manure.