• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.688-692
• /
• 2005

Importance of substitute energy has been increasing due to environmental issues and lack of fossil fuels. In addition, heating cost that occupies from 30 to $40\%$ of the total production cost in Korean protected cultivation needs to be reduced for profitability and global competition. But, studying on substitute energy to solve these problems has not been activated for Korean protected cultivation. Therefore, this study was conducted to develop a geothermal heat pump system for cool ing and heat ing of greenhouses at a lower cost than conventional hot air heater and air conditioner. Fundamental test of heat transfer characteristics in soil was conducted by computer simulation and controlled tests for its verification. Based on the results of the theoretical and empirical investigations, an optimum heat pump system was developed and the performance was evaluated for practical use in a greenhouse at the Pusan Horticultural Experiment Station. The system was compared with a conventional hot air heating system through a cucumber growing test and economic feasibility analysis. Results of the application test of the geothermal heat pump showed that with an initial setting of $15^{\circ}C$ the inside temperature of the greenhouse could be maintained between 15 and $17^{\circ}C$. Results of the cucumber growing test showed that there were no significant differences in average height, leaf length, leaf width, number of nods, leaf area, dry weight and yield between the plots wi th the geothermal heat pump system and a conventional hot air heater. Economic feasibility analysis indicated that the variable cost of the hot air heater could be saved $81.2\%$ using the geothermal heat pump system. It was concluded that the geothermal heat pump system might be a pertinent heating and cooling system for greenhouses because of the low operating cost and the use of environment-friendly geothermal energy.

• Clean Technology
• /
• v.9 no.1
• /
• pp.23-28
• /
• 2003

The generation of food waste in Korea amounts to 4.10 million per year, which corresponds to 820,000 dry ton of organic waste. This has been used traditionally as animal feed or soil conditioner, but its efficacy has remained doubtful in recent years. In this study as an alternative we considered methane production by anaerobic treatment, which has an advantage of 200 million US dollars over aerobic methods. The production of methane amounts to $4.40{\times}10^8m^3$, 3.43% of $1.28{\times}10^8m^3$, total natural gas used in Korea. Furthermore the methane from household kitchen food waste amounts to 28.9% of the total gas used in the kitchen.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.21 no.2
• /
• pp.51-55
• /
• 2013

This research conducted component analysis of pellet fuel using livestock waste and agricultural by-product and combustion characteristics. As the result of analyzing the characteristics of solid fuel using livestock waste, three components, element analysis, and heating value were suitable for the standard of solid fuel. In addition, content of ash consisted of high concentration of K, P, Na indicating the possibile usage as a soil conditioner. However, it was not suitable for solid fuel using only livestock waste due to the relatively low heating value. To improve the heating value and early ignition, we mixed agricultural by-products (i.e., chaff and sawdust) into livestock waste. The mixed material showed significant increase of combustibles and heating value with decrease of moisture content compared to the livestock waste only.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.4 no.2
• /
• pp.35-45
• /
• 1996

In order to investigate the possibility of treating nightsoil sludge, the growth trend experiments with vermicompsting was performed and the stability of worm castings was evaluated by the analysis of minerals according to growth periods. Survival rate(SR) of earthworms decreased as earthworms grow up to 7 weeks. The growth period of the earthworms could be classified into two phases on the basis of the ratios of cast to feed ingested(ID). The growth period of the earthworms up to 3 weeks, the high percentage of dry weight of feed ingested(ID) is mainly utiliz-ed to an increase in fresh weight of earthworms, and after the 3 weeks, it is utilized to cast production in this experiment, respectively. The highest values of increasing rate(IR) and biomass of the earthworms(BE) were obtained at 3 weeks and those were 10.59mg/day and 14.48g, respectively. Between the increasing rate(IR) and biomass of the earthworms(BE), a highly positive correlation coefficient(p<0.001) ap-peared. The highest values of biomass of the earthworms(BE) and cast production(CW) were obtained at 3 and 7 weeks, respectively. All the concentrations of minerals except calcium(Ca) in worm castings was lower than the values in nightsoil sludge. It was considered that the major portion of minerals in nightsoil sludge may have been retained in the bodies of earthworms. And these values were lower than the regulated levels in organic fertilizers that the regula-tion standards. In conclusion, the worm castings are very stable for the use as soil conditioner or organic fertilizers.

• Asian Journal of Turfgrass Science
• /
• v.23 no.2
• /
• pp.317-330
• /
• 2009

Research was initiated to investigate germination vigor, number of leaves, plant height and turfgrass density. A total of 18 treatment combinations were used in the study. Treatments were made of soil organic amendment(SOA), sand, and water-absorbing polymer. Germination vigor, leaf number, plant height and turfgrass density were evaluated in Kentucky bluegrass(KB) grown under greenhouse conditions. Significant differences were observed in germination vigor, leaf number, plant height and turfgrass density among 18 mixtures of SOA and polymer. Highest germination rate was associated with mixture of SOA 20% + sand 80% + polymer 0%, resulting in 56.3% for KB. Number of leaves at 60 DAS(days after seeding) were greater with KB over PR, while plant height higher with PR over KB. Leaf number increased with SOA, being SOA 20% > SOA 100% > SOA 10% and with polymer from 0 to 12%. Plant height was greatest with SOA 20% and lowest with SOA 100%. Greater density was observed with PR rather than KB due to longer plant height. Turf density was best under SOA 10% and poorest under SOA 100% in KB. A further research would be required for investigating the individual effect of K-SAM, Ca, perlite on the turf growth characteristics.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.5
• /
• pp.794-800
• /
• 2011

To develop biochar for soil conditioner using water plants, characteristics of nutrients release of biochars were investigated under different water plants, manufacturing times and manufacturing temperatures. Under different water plants for manufacturing biochar, the concentrations of T-N and $P_2O_5$ in the water with biochars were higher in the order of CRXDM > ZIZLA > PHRCO > TYHOR > MISSA. The concentrations of $K_2O$ in the water were in the order of TYHOR ${\fallingdotseq}$ CRXDM > ZIZLA > PHRCO > MISSA. Under different manufacturing times for biochar, the concentrations of T-N, $P_2O_5$ and $K_2O$ in the water with biochars were higher in the order of 2 hr > 30 min ${\fallingdotseq}$ 1 hr. The concentrations of T-N, $P_2O_5$ and $K_2O$ in the water with biochars were on the order of $350^{\circ}C$ > $500^{\circ}C$ > $600^{\circ}C$ under different manufacturing temperatures. Total amounts of T-N and $K_2O$ releases in the water with biochars were higher in the order of CRXDM > ZIZLA > PHRCO > TYHOR > MISSA. Using biochars by water plants, total amounts of $P_2O_5$ releases in the water with biochars were on the order of CRXDM > ZIZLA > MISSA >PHRCO > TYHOR. The results of this study suggest that biochars by water plants can supply some of the nutrient requirements of crops and can be a valuable fertilizer.

• Korean Journal of Organic Agriculture
• /
• v.17 no.1
• /
• pp.55-62
• /
• 2009

In this paper, we assessed the growth of rice seedlings(Chucheong variety) in commercial organic growth medium that was substituted with different ratios of vermicast of oyster mushroom waste grown under potting alone, and potting and floor layering treatment. The commercial organic growth medium was substituted with vermicast at ratios of control, 2%, 4% and 6%, respectively. The control consisted of commercial organic growth medium alone without vermicast. Incorporation of $4%{\sim}6%$ vermicast of oyster mushroom waste into a commercial organic growth medium enhanced the growth of rice seedlings significantly as compared to commercial organic growth medium alone(control), and 2% amended with vermicast in potting treatment. This results demonstrate that substitution with low ratios of vermicast($4%{\sim}6%$) will promote growth of rice seedlings. The growth of rice seedlings in commercial organic growth medium alone without vermicast was enhanced significantly as compared to the substituted with vermicast in floor layering treatment, it may due to nutrient uptake by elongated root from the vermicast when applied to on the floor layering. Floor layering treatment is an effective method for potting processing of vermicast. The vermicast of oyster mushroom waste should have a high safety and great potential as materials of growth media for increasing plant growth, either as soil conditioner, or as substitution or amendments to commercial organic growth medium. For the enhanced growth of rice seedlings, demand to increase with total nitrogen, and decrease with the carbon and nitrogen ratio(C/N) of commercial organic growth medium supplied by such as vermicast.

• Korean Journal of Organic Agriculture
• /
• v.16 no.3
• /
• pp.287-298
• /
• 2008

This experiment was carried out to investigate the effect of different feed conditions on growth, cast production and conversion efficiency of organic matter to the earthworm. The experiment was tested on cow manure(CM) mixed with rice hulls (RH) or rice straw(RS). The mixture ratios were designed as one time, two times and three times of cow manure volume, respectively. The CM and RH mixtures resulted better on growth rate, reproductive efficiency and wormcast production than those for CM and RS mixtures. Especially on three times of RH mixture showed the highest growth characteristics compared to the other mixtures. Although both were between 20 and 34 on carbon and nitrogen ratio, the result inferred that the difference on the growth might have been caused by feeding conditions. On the mixtures of cow manure with rice hulls(CM+RH) was significantly higher on values on the conversion rate and conversion efficiency of organic matter to earthworm tissues than the mixtures of cow manure with rice straw(CM+RS). The most concerned point of the mixture of earthworm feed is that high contents of volatile solid and total carbon that increases in conversion efficiency of organic matter to earthworm tissues, and also causes the increase in growth rate and reproductive efficiency. The wormcast could be used as a valuable plant growth medium or soil conditioner for sustainable agriculture and it may be due to their high qualities of physico-chemical properties.

• Journal of Animal Environmental Science
• /
• v.12 no.3
• /
• pp.161-168
• /
• 2006

This paper describes the changes of characteristics of pig slurry according to storing depth. Most of the substances containing pollutants, such as were Management of manure and wastewater from animal confinement facilities is a critical factor for pollution control. With proper treatment processing method in both solid and liquid forms, it can be used as a fertilizer and soil conditioner. In Korea, liquid-manure handling system is very popular because its treatment and application is easy and labor saving. In the storage tank treatment, the period of fermentation process and solids-liquid separation averages six months and the supernatant liquid is being used as a fertilizer. In this study, the changes in chemical characteristics of pig slurry at varying depths of the storage tank were investigated. Results showed that the pH value of the fermented pig slurry was > 7, while the major pollutants such as BOD, SS, N and P were highest in the bottom of the tank. Therefore, the above findings proved that varying depths in the storage tank can influence the concentration of pollutants of the fermented pig slurry.

• Parasites, Hosts and Diseases
• /
• v.57 no.4
• /
• pp.341-357
• /
• 2019

Acanthamoeba, one of free-living amoebae (FLA), remains a high risk of direct contact with this protozoan parasite which is ubiquitous in nature and man-made environment. This pathogenic FLA can cause sight-threatening amoebic keratitis (AK) and fatal granulomatous amoebic encephalitis (GAE) though these cases may not commonly be reported in our clinical settings. Acanthamoeba has been detected from different environmental sources namely; soil, water, hotspring, swimming pool, air-conditioner, or contact lens storage cases. The identification of Acanthamoeba is based on morphological appearance and molecular techniques using PCR and DNA sequencing for clinico-epidemiological purposes. Recent treatments have long been ineffective against Acanthamoeba cyst, novel anti-Acanthamoeba agents have therefore been extensively investigated. There are efforts to utilize synthetic chemicals, lead compounds from medicinal plant extracts, and animal products to combat Acanthamoeba infection. Applied nanotechnology, an advanced technology, has shown to enhance the anti-Acanthamoeba activity in the encapsulated nanoparticles leading to new therapeutic options. This review attempts to provide an overview of the available data and studies on the occurrence of pathogenic Acanthamoeba among the Association of Southeast Asian Nations (ASEAN) members with the aim of identifying some potential contributing factors such as distribution, demographic profile of the patients, possible source of the parasite, mode of transmission and treatment. Further, this review attempts to provide future direction for prevention and control of the Acanthamoeba infection.