Jessie Pascual Bitog

Monitoring of the Fugitive and Suspended Dust Dispersion at the Reclaimed Land and Neighboring Farms: Monitoring in Gim-je

A study on fugitive dust dispersion was conducted at Saemanguem reclaimed area located at the west coastal area of Jeon-buk Province Total reclaimed area is 40,100ha developed by building a 33km long sea dike through Gunsan, Gimje, and Buan. (Land: 28,300ha, Fresh Water Lake: 11,800ha) After this area was completely reclaimed in 2006, there has been high possibility of dust generation and dispersion to the neighboring area. The dust generated at the reclaimed land was composed mainly of minerals with high salinity, and it could make harmful effect on crop production as well on to human`s health such as eye irritation and respiratory disease. Especially, when those aerosol particles are reached on the leaves of farm crops, the photosynthesis and respiration of the plants can be under restraint resulting in the decrease of agricultural productivity of the nearby farm areas. Furthermore, highly concentrated salty particles can directly damage the leaf cells. In this study, field experiment has been conducted to regularly measure the locally suspended dust particles and analyze how they were dispersed to the neighboring areas. The collected dust particles were analyzed to examine theirs sizes, concentrations, and components. The SPSS statistical program was also used to separate the dust concentration generated by the reclaimed land from the total dust concentration measured at the measuring locations.

Analysis on the Optimum Location of an Wet Air Cleaner in a Livestock House using CFD technology

ABSTRACT In South Korea, as the living standard has been getting higher, meat consumption is steadily increasing. To meet the countrys demand, livestock houses become larger and wider with increased raising density. In larger livestock houses, pollutants such as flake of pig skin, excrement, odor, various dusts and noxious gas like ammonia are excessively accumulated inside the facility. These will cause weak immunity for the pigs, diminution of productivity and degeneration of working condition. These problems can be solved through the ventilation performance of the facility. In the winter time, ventilation must be controlled to minimum to maintain a suitable thermal condition. However, this affects the other internal environmental condition because of the minimum ventilation. The installation of “wet air cleaner” especially in the winter time can be an alternative solution. For efficient application of this machine, there is a need to understand the existing ventilation condition and analyze the interaction of existing ventilation system with the wet air cleaner considering its appropriate location. In this study, the existing ventilation system as well as the internal environmental condition negatively inside the facility with the wet air cleaner has been studied using CFD technology. The CFD simulation model was validated from the study conducted by Seo et al. (2008). Results show that the elimination rate of ammonia was 39.4 % and stability could be improved to 35.1 % (Comparing case 5 to 1 where wet air cleaner machine was not used). It can therefore be concluded that case 5 shows the optimum location of a wet air cleaner in the livestock house.

Analysis of the Disease Spread in a Livestock Building Using Tracer Gas Experiment

Recently, the livestock industry in Korea was heavily affected by the outbreak of official livestock diseases such as foot and mouse disease, high pathogenic avian influenza, swine influenza, and so on. It has been established that these diseases are being spread through direct contact, droplet and airborne transmission. Among these transmissions, airborne transmission is very complex in conducting field investigation due to the invisibility of the pathogens and unstable weather conditions. In this study, the airborne transmission was thoroughly investigated inside a pig house by conducting tracer gas () experiment because experiment with real pathogen is limited and dangerous. This is possible as it can be assumed that the flow is similar pattern very fine particles and gas. In the experiment, the ventilation structure as well as the location of gas emission were varied. The detection sensors were installed at 0.5 and 1.3 m height from the floor surface. The tracer gas level was measured every second. Results revealed that the direction of spread can be determined by the response time. Response time refers to the time to reach 150 ppm from the gas emission source at each measuring points. The location of the main flow as well as the gas emission was also found to be very important factor causing the spread.

Assessment of Instrument Efficiency in Detecting Airborne Virus

In livestock industry, damage caused by the epidemic diseases such as Foot-and-Mouth Disease (FMD), Highly-Pathogenic-Avian-Influenza (HPAI) and Porcine-Reproductive-and-Respiratory-Syndrome (PRRS) was very serious. The financial loss incurred from FMD alone which occurred on Nov. 2011 in Korea was estimated at 3 billion won, 23 % of annual livestock industry production. The livestock industry in Korea has greater risk of disease infection because of high density production, etc. Investigating the spread of livestock diseases should consider both direct and indirect contact as well as other various factors including airborne. Airborne infection of livestock disease was first hypothesised in the early 1900s, however, field experimental studies are still limited. Furthermore, no protocol is available in detecting airborne viruses in the field. In this study, effective virus samplers were investigated by comparative analysis of the type of samplers used detect to airborne virus. Laboratory experiments were conducted to compare virus samplers such as Bio-sampler, Dust-sampler, Compact-Cascade-Impactor (CCI) and Microflow in detecting PRRSV. Samples were analyzed by Reverse-Transcription PCR to assess the efficiency of the instrument in detecting the airborne virus. First, samples were classified into five levels according to light intensity of gel images and then the classified results were normalized. In every case, Bio-sampler and Dust-sampler were comparable with each other and have shown to be more effective than CCI and Microflow samplers.

Quantitative evaluation of bubble-column photo-bioreactors for bio-diesel production from microalgae using computational fluid dynamics

Renewable energy has been interested as a countermeasure for the fossil energy depletion and carbon dioxide reduction. Bio-diesel is one of the most desirable renewable energy because it can be an alternate diesel to petroleum. However, the bio-diesel from soybean or corn, for example, can be confronted with food crisis. Microalgae have recently been researched as a new bio-diesel source which contains higher growth rate than other plants. Microalgae residue also could be used for value-added products such as cosmetics, health functional food or pharmacy. Because pond production system has limitations in unstable weather conditions and insufficient land availability especially in Korea, photo-bioreactors is essential for their cultivation.

Development of an Assessment Model for Greenhouse Using Geothermal heat pump system

In Korea, the heating cost for the Horticulture industry is considering as a big problem where it occupies about 58% from total costs. Almost 80% from the heating systems are using fossil fuel where it cause economic crisis. Since industrialization, environment pollution, global warming and lack of natural resource were occurred because of increased rapidly using of fossil fuel. Among the renewable energy, ground heat pump system is suitable to control internal environmental conditions in greenhouse where it has a steady temperature. Generally conventional greenhouses are using the oil heating system during the cold season. Accordingly, the geothermal heating system is used for reducing costs of heating, management and operation. But the initial investments of the geothermal heating system are very high in comparison to conventional heating system because of its equipment costs. Consequently, according to exact calculations of heating load, greenhouse geothermal heating systems must be designed efficiently.

Analyzing Ventilation efficiency using Age of air theory and CFD technology

In agricultural-buildings like livestock houses and greenhouses, environmental conditions are controlled by ventilation-systems. Comprehension of ventilation is important to improve the internal growth conditions. Notable researchers in the field of architectural-science have been using “Age-of-air” theory to investigate ventilation-efficiencies. However, this has not yet been applied in agricultural fields. The concepts of LMA and LMR were used to evaluate the-distribution of fresh air and the potential for eliminating-contaminants. However, experiments had been limited due to a shortage of experimental-devices and unstable tracer-gas. In this study, the Age-of-air concept and CFD were employed to address the mentioned limitations. A 3-dimensional chamber was designed to accurately implement and verify the Age-of-air concept via simulation analysis. The simulation results were compared with the results of the experiment which was conducted via the tracer-gas approach. In validating the computations of the LMAs and LMRs, the results showed similar tendencies of distribution and average errors of 9 and 13%, respectively. It was concluded that the simulation for implementation of the Age-of-air was designed reasonably. The results showed that when the ventilation rate increased, the Age-of-air values decreased; however, when comparing air exchange efficiencies, the values had an opposite tendency. Based on the results, the research could be upgraded to quantitatively determine the overall or local ventilation-efficiencies in agricultural-facilities using the Age-of-air theory

Aerodynamic Approaches for the Predition of Spread the HPAI (High Pathogenic Avian Influenza) on Aerosol

HPAI (Highly pathogenic avian influenza) which is a legally designated epidemic disease generally shows rapid spread resulting in high mortality rate as well as severe economic damages. Because Korea is neighbor with China and south-east Asia where HPAI have occurred frequently, there is a high possibility for HPAI outbreak. A prompt treatment against epidemics is most important for minimize of disease spread. The spread of HPAI should be considered by both direct and indirect contact as well as various spread factors including airborne spread. There is high risk of rapid propagation of HPAI via air because most of farms in Korea are collective. Field experiments for the mechanism of disease spread have limitations such as unstable weather condition and difficulties in maintaining experimental conditions. In this study computational fluid dynamics which has been actively used for mass transfer modeling were adapted. Korea has complex terrains and many livestock farms are located in the mountain regions. GIS was also used to estimate spreads of virus attached aerosol by means of designing three dimensional complicated geometry including farm location, road network, and related facilities. This can be used as back data in order to take preventive measures against HPAI occurrence and spread.

Monitoring and CFD prediction for fugitive dust dispersion in the reclaimed land in Korea

Fugitive dust dispersion was studies in Saemangeum reclaimed land which developed 40,100 ha and located at the west coastal part of Korea. The salty dusts can affect to nearby farms. A computational fluid dynamics (CFD) model was developed to predict the dispersion of fugitive dust considering the topography of the area. Results showed that the dust concentrations are highly connected with the changes of dust source area. The dust concentration has been decreased from 2006 to 2010, and it is expected to decrease further as more dust source areas are being covered by plants. Dust dispersion ranges of CFD result were compared with that of field experiment at the same measuring points for the CFD validity, and the results at stable weather condition were very acceptable with a 6.8% error. On the basis of 10 µm particle size, the dispersion distance of fugitive dust resulted in about 2,500m with the wind velocity of 5.0m/s.

Study on Incidence of Respiratory Disease According to Configurations of Structural and Ventilation System Using Aerodynamic Approaches

The typical diseases for pigs in Korea are porcine epidemic diarrhea (PED), porcine reproductive and respiratory syndrome (PRRS), post-weaning multi-systemic wasting syndrome (PMWS), and porcine respiratory disease complex (PRDC). The main factors for the occurrence of these diseases, specifically the respiratory diseases, are the environmental conditions, particularly ventilation inside the pig house. Considering that Korea has 4 distinct seasons, the environmental conditions in a pig house change every season. The purpose of this study was to find the relationship between the structural configuration of the ventilation system of a pig house and the occurrence of pig respiratory disease. It was analyzed that there is an effect of internal airflow distribution to internal disease dispersion in a pig house. Several field experiments were conducted at several commercial pig farms to understand the environmental control in relation to disease occurrence. To overcome the difficulties of conducting field experiments and obtaining internal airflow visualization quantitatively and qualitatively, computational fluid dynamic (CFD) and building energy simulation (BES) technologies have been simultaneously used. The accuracy of the simulations was preliminarily examined and improvements were made in the model based from the seasonally collected farm data.