• KSBB Journal
• /
• v.14 no.1
• /
• pp.114-118
• /
• 1999

In order to use a polysaccharide, curdlan, as a concrete admixture, we first developed a pilot-scale fermentation process for the mass production of curdlan. We also examined the rheological properties of curdlan, and tested how well the curdlan obtained in this work increased the segregational resistance of the cement slurry. Fermentation was performed in a 300-liter fermenter equipped with 3 disk-turbine impellers. Since curdlan production is stimulated under nitrogen-limiting conditions, the culture pH was shifted from the optimal pH for cell growth (pH 7.0) to the optimal pH for curdlan production (pH 5.5) at the onset of ammonium exhaustion. We obtained a curdlan production of 65 g/L in 120 hr batch cultivation of Agrobacterium species. The insoluble curdlan at the final stage of fermentation was readily harvested by centrifugation together with the cells. The freeze-dried sample contained 78% (w/w) of curdlan. The solubility and viscosity of the curdlan increased with the increase of the solution pH, which enhances the viscosity of concrete since the pH of concrete is extremely high (pH 13.0). Test results of the curdlan as a concrete admixture with cement slurry demonstrated that it prohibits the leakage of water. In conclusion, this work certifies and enlarges curdlan's industrial potential as a concrete admixture.

• Animal Bioscience
• /
• v.35 no.12
• /
• pp.1977-1985
• /
• 2022

Objective: This study was conducted to determine the seasonal characteristics of odorous material emissions from a swine finishing barn equipped with a continuous pit recirculation system (CPRS) using aerobically treated manure. Methods: The CPRS consists of an aerobic manure treatment process and a pit recirculation system, where the solid fraction is separated and composted. The aerated liquid fraction (290.0%±21.0% per day of total stored pig slurry) is continuously recirculated to the top of the slurry in the pit. Four confinement pig barns in three piggery farms were used: two were equipped with CPRS, and the other two operated a slurry pit under the slatted floor across all seasons. Results: The indoor, exhaust, and outside odor intensities were significantly lower in the CPRS group than in the control group (p<0.001). In the CPRS group, the odor intensity outside was significantly lower in the fall than in the other seasons (p = 0.015). In the indoor atmosphere, the temperature and CO₂, NH₃, and H₂S contents of the CPRS group were significantly lower than those of the control group (p<0.05). In the CPRS group, indoor temperature did not significantly change in the spring, summer, and fall seasons and was significantly lower in the winter (p = 0.002). NH₃, H₂S, methyl mercaptan, dimethyl disulfide, trimethylamine, phenol, indole, and skatole levels were significantly lower in the CPRS group than in the control group (p<0.05). There were significant seasonal differences on the odorous material in both the control and CPRS groups (p<0.05), but the pattern was not clear across seasons. Conclusion: The CPRS can reduce the indoor temperature in the summer to a level similar to that in the spring and fall seasons. The CPRS with aerated liquid manure is expected to reduce and maintain malodorous emissions within acceptable limits in swine facilities.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.11
• /
• pp.1833-1839
• /
• 2018

Objective: Incorporating high fibre ingredients into pig diets has the potential to reduce odour emissions from of pigs. The current study was carried out to determine effect of diets containing 0, 80 and 160 g/kg of each of lucerne hay, maize cobs and sunflower husks on the chemical characteristics and odours from pig slurries. Methods: Twenty eight pigs averaging $18{\pm}2.0kg$ were kept in individual cages, over four weeks. All pigs were fed ad libitum. Faeces and urine were collected, mixed in a 1:2.3 ratio (w/w), stored and fermented for 16 days in a temperature controlled room at $22^{\circ}C{\pm}2.3^{\circ}C$. The slurry was sampled twice (on day 1 and on day 16) of the fermentation period and analysed for pH, chemical oxygen demand (COD), nitrogen and short chain fatty acids (SCFA) concentration, on wet basis. All samples were tested for odour offensiveness using 18 panelists. A scale of 1 to 5 was used to rank the odour severity, (1 = not offensive, 5 = extremely offensive). Results: Slurry pH and COD varied with fibre source (p<0.05). On day 16, COD for lucerne hay, sunflower husk and maize cobs were 369, 512, and 425 (standard error of the mean = 34.2) mg of oxygen per litre. Total SCFA concentration was higher at day 16 than day 1 (p<0.05). Odour offensiveness varied with fibre source across both incubation periods (p<0.05). Sunflower husks and lucerne hay-based diets were rated as less offensive (mean rank = 2.2) than maize cob diets (mean rank of 4.3) (p<0.05). Conclusion: It was concluded that different fibre sources and incubation period influence chemical composition and odour of the slurry. There is, thereby, a need to incorporate locally available fibrous feeds in the diet of pigs because they have an economical and environmental relevance to pig management.

• Journal of Animal Environmental Science
• /
• v.15 no.2
• /
• pp.161-170
• /
• 2009

This experiment was conducted to investigate the effects of compost leachate and concentrated pig slurry on growth of pepper in substrate hyrdoponic culture. In process of composting, compost leachate was was through a saturated compost heap. Pig slurry was filtered by ultra filtration and concentrated by reverse osmosis process. The pig slurry was mixed with chemical nutrient solution and byproduct based on nitrogen content. Peppers were grown in the seven different hydroponic solutions; compost leachate (CL), concentrated pig slurry (CS), compost leachate + byproduct (CL+BP), concentrated pig slurry + byproduct (CS+BP), compost leachate 50% + nutrient solution 50% (CL+NS), concentrated pig slurry 50% + nutrient solution 50% (CS+NS) and chemical nutrient solution for pepper. The chemical nutrient solution was the standard solution of National Horticulture Research Station for the growth of pepper. The concentration of nutrient solution was adjusted $1.6{\sim}2.0mS/cm$ in EC. The compost leachate and concentrated pig slurry were low in phosphorus (P), calcium (Ca), magnesium (Mg), but rich in potassium (K). Growth characteristics as affected by the different nutrient solution were significantly different. Growth and fruit characteristics treated with CL 50+NS 50%CS and 50+NS 50% were similar with NS 100% control plot. The dry weight of stem and leaf were 107.4, 104.2g in plot of NS 100% and CS 50%+NS 50%, respectively. The fruit of pepper showed lowest in the plot treated with 100% concentrated pig slurry, and the growth of pepper severely decreased after application of 100% CS treatment. The yield of pepper was not significantly different between the plots treated with mixture of CS50 + NS50% and 100% nutrient solution treatment. Fruit yield of the compost leachate concentrated pig slurry plot were 59, 14% compared to control, repectively. In conclusion, the mixture solution of 50% of pig slurry and 50% of nutrient solution could be used as a nutrition solution of pepper in hydroponic culture.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.9
• /
• pp.787-792
• /
• 2005

Chemical mechanical polishing(CMP) has become the process of choice for modem semiconductor devices to achieve both local and global planarization. CMP is a complex process which depends on numerous variables such as macro, micro and nano-geometry of pad, relative velocity between pad and wafer stiffness and dampening characteristics of pad, slurry, pH, chemical components of slurry, abrasive concentration, abrasive size, abrasive shape, etc. Especially, an oxidizer of chemical components is very important remove a target material in metal CMP process. This paper introduces the effect of oxidizer such as $H_2O_2,\;Fe(NO_3)_3\;and\;KIO_3$ in slurry for tungsten which is used in via or/and plug. Finally the duplex reacting mechanism of $oxidizer(H_2O_2)$ through adding the $catalyst(Fe(NO_3)_3)$ could acquire the sufficient removal rate in tungsten CMP.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.12 no.9
• /
• pp.860-869
• /
• 2000

The thermal conductivity and density of slurries entrained with the particles of Micro-PCM are measured with respect to its temperatures as well as concentrations. For the thermal conductivity of slurries, a device made from P.A. Hilton (Model No. H470) is adopted. There is a well-scaled 0.3 mm gap between shells into which the slurry is injected. The temperatures of the slurry are changed to $5~25^{\circ}C$ , for which it is controled by the supplied voltage and cooling water circulated around the outer shell. The concentrations of Micro-PCM slurries are varied from 5 wt% to 50 wt%. Some general equations such as Maxwell's equation, are evaluated for their applicability with Micro-PCM slurry. As a result, it happens to be some 20% discrepancy between the experiment and the applied equations. The density measurements of Micro-PCM slurry to its temperature and concentration are peformed by hydrometer. For the experiment, tetradecane encapsulated slurry (($t_m≒6^{\circ}C$) and a mixed wax ($t_m≒50^{\circ}C$) are tested. The temperature changes of tetradecane are applied for $0^{\circ}C\;to\;$20^{\circ}C$and a mixed wax for $20^{\circ}C\;to\;$60^{\circ}C$ and its concentrations are changed from 5 wt% to 30 wt%. The results are compared with a general equation and the referenced data. For the conclusion, the experimental result and a general equation are well agreed.

• Korean Journal of Organic Agriculture
• /
• v.17 no.3
• /
• pp.357-370
• /
• 2009

This experiment was conducted to investigate the effects of compost leachate and concentrated slurry on growth of tomato in hydroponic culture. In process of composting, compost leachate was produced water was through a saturated compost heap. The concentrated slurry was produced by filtration and concentration by membrane process. Filtration of pig slurry was necessary to prevent the hose clogging in hydroponics culture. The treatments of this experiment were consisted of seven different liquid fertilizers; compost leachate(CL), concentrated pig slurry (CS), compost leachate+byproduct(CL+BP), concentrated pig slurry+byproduct(CS+BP), compost leachate 50%+nutrient solution50%(CL+NS), concentrated pig slurry 50%+nutrient solution50%(CS+NS) and nutrient solution(NS) for tomato based on nitrogen content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of tomato. The concentration of nutrient solution was adjusted a range of $1.6{\sim}2.0 mS/cm$ in EC. 1. The compost leachate and concentrated pig slurry were low in phosphorus(P), calcium(Ca), magnesium(Mg), but rich in potassium(K). 2. Plant height, SPAD value of tomato was highest in the plot of CS+NS, intermediate in CL, CS+BP, and lowest in 100% concentrated pig slurry. 3. The tomato yield of compost leachate plot was 91% compared with inorganic nutrient solution. The compost leachate solution could be used as a nutrition solution of tomato in organic hydroponics. 4. The growth including plant height, SPAD value, fruit number, fruit weight and yield of tomato in the CL 50%+NS 50% was similar in the control. In conclusion, the mixture solution of 50% pig slurry and 50% nutrient solution could be used as a nutrition solution of tomato hydroponic culture.

• Journal of the Korean Applied Science and Technology
• /
• v.34 no.4
• /
• pp.746-755
• /
• 2017

In this study, $CeO_2/TiO_2$ nanoparticle with structure of core and shell was synthesized by growing $TiO_2$ onto the surface of $CeO_2$ according to hydrolysis of $Ti(SO_4)_2$. Reaction time, temperature, concentration of $CeO_2$ slurry, pH control of $Ti(SO_4)_2$ were optimized about synthesis of $CeO_2/TiO_2$ core-shell nanoparticle. It was found that optimal mole ratio range of $CeO_2:TiO_2$ was 1:0.2~1.1, the optimal concentration of $CeO_2$ slurry was 1 %, and the optimal reaction temperature was $50^{\circ}C$. The optimal concentration of $CeO_2$ slurry could be increased up to 10 % by adjusting the pH of $Ti(SO_4)_2$ to 1 using $NH_4OH$ and adding to $CeO_2$ slurry. If reaction was carried at $80^{\circ}C$ or higher, the separated $TiO_2$ particles were obtained instead of $CeO_2/TiO_2$ core-shell nanoparticles. The optimal reaction temperature was $50^{\circ}C$ at which good shaped core-shell structure of $CeO_2/TiO_2$ was obtained.

• Tribology and Lubricants
• /
• v.33 no.5
• /
• pp.228-233
• /
• 2017

Chemical Mechanical Polishing of chemically stable sapphire substrates is dominantly affected by the mechanical processing of abrasives, in terms of the material removal rate. In this study, we investigated the effect of electrostatic force between the abrasives and substrate, on the polishing. If potassium chloride (KCl) is added to slurry, water molecules are decomposed into $H^+$ and $OH^-$ ions, and the amount of ions in the slurry changes. The zeta potential of the abrasives decreases with an increase in the amount of $H^+$ ions in the stern layer; consequently, the electrostatic force between the abrasives and substrate decreases. The change in zeta potential of abrasives in the slurry is affected by the slurry pH. In acidic zones, the amount of ions bound to the abrasives increases if the amount of $H^+$ ions is increased by adding KCl. However, in basic zones, there is no change in the corresponding amount. In acidic zones, zeta potential decreases as molar concentration of potassium increases; however, it does not change significantly in basic zones. The removal rate tends to decrease with increase in molar amount of potassium in acidic zones, where zeta potential changes significantly. However, in basic zones, the removal rate does not change with zeta potential. The tendencies of zeta potential and that of the frictional force generated during polishing show strong correlation. Through experiments, it is confirmed that the contact probability of abrasives changes according to the electrostatic force generated between the abrasives and substrate, and variation in removal rate.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.5
• /
• pp.1266-1272
• /
• 2007

The current study was conducted to investigate the effects of dietary complex probiotics supplementation on growth performance, nutrient digestibility, blood characteristics and noxious gas emission of manure slurry in growing pigs. A total of forty eight pigs with an initial body weight of 20.12 kg were allotted to three dietary treatments (two pigs per pen with eight pens per treatment). Dietary treatment included: 1) CON (basal diet), 2) Pro1 (basal diet + 0.1% complex probiotics) and 3) Pro2 (basal diet + 0.2% complex probiotics). The experiment was lasted six weeks. Through the entire experimental period, ADG was increased with the increased complex probiotics supplementation level (linear effect, P<0.05). However, neither ADFI nor gain/feed was influenced by the dietary treatments. Complex probiotics supplementation increased DM digestibility (linear effect, P<0.05). Also, the N digestibility was improved, with the Pro1 treatment showed highest value (linear and quadratic effect, P<0.05). Supplementation of complex probiotics did not affect the WBC, RBC, lymphocyte and BUN concentrations in blood. The $NH_3-N$ emission from manure slurry was decreased with the increased level of complex probiotics supplementation (linear and quadratic effect, P<0.05). Similarly, $H_2S$ emission of manure slurry was also decreased significantly when complex probiotics was included in diet (linear effect, P<0.05). In conclusion, dietary supplementation of Complex probiotics can increase growth performance and decrease noxious gas emission of manure slurry in growing pigs.