• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.447-453
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• 2004

The prevalence of Toxocara canis eggs in the public places in the city of Gwangju were studied through examination of 800 soil and 123 fecal specimens. Toxocara canis eggs were found in 15% of soil samples. In 25% parks and 17% residential quarters, these eggs were detected with higher contamination rate than other places. The soil contamination rate of playgrounds in spring and autumn was higher than that of summer and winter, and the variation range of the rate was high in parks and residential quarters. The contamination rate of eggs in 123 samples of dogs' feces was 31%, it was higher than that of soil samples(21%).

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.2
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• pp.220-225
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• 1999

The environmental conditions in smallholder dairy farms especially the effects of dairy wastes on waters and soil were the main objectives of this investigation. Forty-three dairy farms from an older dairy cooperative (Nongpho Dairy Cooperative, NP) were compared with four dairy fauns from relatively new dairy cooperative (Kamphaengsaen Dairy Cooperative, KS) for the quality parameters of water and soil samples during a 12-month period. Forty-three farms at NP were from three geographical areas and three levels farm crowdedness. The results from this study clearly showed that the waste waters from older dairy barns contained much higher levels of organic and inorganic substances which could create environmental pollution if not properly managed. The differences in waste water qualities due to areas and seasons were not significant, while waste water samples from crowded farms tended to contain higher averages of waste water parameters such as COD and BOD. Highly significant correlations between pairs of waste water parameters indicated that certain parameters can be used without the need for chemical analysis of some other parameters. The qualities of well water on dairy farms as well as water samples from public waterways nearby indicated some contamination of dairy wastes such as manure. Storage and sun-drying of dairy manure on bare soil surface could result in the contamination of underground water and nearby water sources. Some recommendations from this study if implemented can prevent environmental pollution in smallholder dairy farms.

• Geomechanics and Engineering
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• v.22 no.2
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• pp.143-152
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• 2020

In this research, soil samples of the Kerman sedimentary basin, Iran, were investigated through laboratory tests such as petrography (Scanning Electron Microscopy (SEM), X-Ray Fluorescence Spectroscopy (XRF) and X-Ray Diffraction (XRD)), physical and mechanical characteristics tests. The soil in this area is dominantly CL. The petrography results showed that the dominant clay mineral is Illite. This soil has made some problems in the earth dams due to the low shear strength. In this study, a set of samples were prepared by adding different amounts of lime. Next, the petrography and strength tests at the optimum moisture content were performed. The results of SEM analysis showed substantial changes in the soil structure after the addition of lime. The primary structure was porous and granular that was changed to a uniform and solid after the lime was added. According to XRD results, dominant mineral in none stabilized soil and stabilized soil are Illite and calcite, respectively. The pozzolanic reaction resulted in the reduction of clay minerals in the stabilized samples and calcite was known as the soil hardener material that led to an increase in soil strength. An increase in the hydrated lime leads to a decrease in their maximum dry unit weight and an increase in their optimum moisture content. Furthermore, increasing the hydrated lime content enhanced the Unconfined Compressive Strength (UCS) and soil's optimum moisture. An increase in the strength is significantly affected by the curing time and hydrated lime contents, as the maximum compressive strength is achieved at 7% hydrated lime. Moreover, the maximum increase in the California Bearing Ratio (CBR) achieved in clay soils mixed with 8% hydrated lime.

• Journal of Environmental Science International
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• v.19 no.1
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• pp.17-26
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• 2010

To understand the initial changes in the microbial activities of wetland soil after construction, dehydrogenase activity (DHA) and denitrification potential (DNP) of soil from 1 natural wetland and 2 newly constructed wetlands were monitored. Soil samples were collected from the Daepyung marsh as a natural wetland, a treatment wetland in the West Nakdong River, and an experimental wetland in the Pukyong National University, Busan. The results showed that the DHA of the natural wetland soil was 6.1 times higher than that of the experimental wetland and similar to that of the treatment wetland 6 months after wetland construction (fall). Few differences were observed in the DNP between the soil samples from the natural wetland and 2 constructed wetlands four months after wetland construction (summer). However, 6 months after the construction (fall), the DNP of the soil samples from the natural wetland was 12.9 times and 1.8 times higher than that of the experimental wetland and the treatment wetland, respectively. These results suggested that the presence of organic matter as a carbon source in the wetland soil affects the DHA of wetland soil. Seasonal variation of wetland environment, acclimation time under anaerobic or anoxic wetland conditions, and the presence of carbon source also affect the DNP of the wetland soil. The results imply that the newly constructed wetland requires some period of time for having the better contaminant removal performance through biogeochemical processes. Therefore, those microbial activities and related indicators could be considered for wetland management such as operation and performance monitoring of wetlands.

• The Journal of Engineering Geology
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• v.32 no.3
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• pp.401-410
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• 2022

This work reports an oven drying test performed on weathered granite soil from Yecheon, Korea, in order to find an effective method for measuring the weight of pure soil particles. After samples were oven dried, weights measured following desiccation using the method specified by the Korean Industrial Standard (KS F) were compared with weights measured without prior desiccation. Soil samples exposed to air for 45 min after oven drying absorbed moisture from the air and gradually increased in weight. When a desiccator was used, results measured 30 s after exposure to air indicated weight increases of 0.103-0.735% (depending on the particle size of the soil) relative to equivalent samples measured without desiccation. Using a desiccator after oven drying leads to overestimation of the pure soil weight. Therefore, measuring the weight of a soil sample immediately after oven drying without using a desiccator can reduce the error of weight measurement.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.393-398
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• 2007

The present study was carried out to investigate the serum minerals profile in buffaloes (Bubalus bubalis) suffering from parturient haemoglobinuria (PHU) along with minerals profile of soils and fodders from the disease prone areas and their interrelationships. Serum samples were collected from 60 each of healthy and PHU affected buffaloes randomly selected from field cases. Serum samples were collected from each animal. Fifty composite soil samples were collected where PHU was prevalent. Fifty samples of fodders including leaves and stems being fed to the diseased buffaloes were collected. The difference in the levels of calcium and potassium between upper and lower soil surface of disease prone areas under study were statistically non-significant. The mean values of phosphorous, copper, iron, selenium and molybdenum in upper soil surface were significantly (p<0.05) higher than in lower soil surface. None of the fodders offered to the diseased animals met the dietary requirements of phosphorus and copper whereas none of the fodders was deficient in potassium, iron and selenium rather were having excess of potassium, iron and selenium. The concentration of calcium was adequate in lucerne, berseem, sarson and sorghum, while maize, sugarcane and wheat straw did not meet the required levels for dairy animals. Molybdenum contents in all fodders were adequate to meet the dietary requirements of the dairy buffaloes. Serum phosphorus, copper and selenium were significantly (p<0.001) lower whereas potassium, iron and molybdenum in buffaloes suffering from PHU were significantly (p<0.001) higher than in healthy buffaloes. It was concluded that phosphorous deficient soils play a major role by transferring this deficiency to plants and ultimately reaching to animals where hypophosphataemia is a consistent finding.

• Geomechanics and Engineering
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• v.17 no.1
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• pp.31-45
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• 2019

In this study the spatial variability of soils is substantiated physically and numerically by using random field theory. Heterogeneous samples are fabricated by combining nine homogeneous soil clusters that are assumed to be elements of an adopted random field. Homogeneous soils are prepared by mixing different percentages of kaolin and bentonite at water contents equivalent to their respective liquid limits. Comprehensive characteristic laboratory tests were carried out before embarking on direct shear experiments to deduce the basic correlations and properties of nine homogeneous soil clusters that serve to reconstitute the heterogeneous samples. The tests consist of Atterberg limits, and Oedometric and unconfined compression tests. The undrained shear strength of nine soil clusters were measured by the unconfined compression test data, and then correlations were made between the water content and the strength and stiffness of soil samples with different consistency limits. The direct shear strength of heterogeneous samples of different stochastic properties was then evaluated by physical and numerical modelling using FISH code programming in finite difference software of $FLAC^{3D}$. The results of the experimental and stochastic numerical analyses were then compared. The deviation of numerical simulations from direct shear load-displacement profiles taken from different sources were discussed, potential sources of error was introduced and elaborated. This study was primarily to explain the mathematical and physical procedures of sample preparation in stochastic soil mechanics. It can be extended to different problems and applications in geotechnical engineering discipline to take in to account the variability of strength and deformation parameters.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.7
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• pp.757-763
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• 2006

In our previous studies, we have isolated bacteria from BTEX-contaminated sediment, which utilized BTEX as a sole carbon source and $NO_3$-N as an electron acceptor. For the possibility of field application, we have applied co-culture of those isolates in the BTEX-contaminated soil and evaluated their biodegradation efficiencies. To investigate the relationship between the isolates and indigenous microorganism in soil, changes of microbial community structure in soil samples with respect to time were monitored. To examine this, soil samples were artificially contaminated with benzene, toluene, ethylbenzene and o-xylene. BTEX-degrading bacteria such as Pseudomonas stutzeri strain 15(DQ 202712), Klebsiells sp. strain 20(DQ 202715) and Citrobacter sp. strain A(DQ 202713) were injected into the soil samples in the ratio of 2:1:1. Our results showed that the highest BTEX biodegradation efficiency was achieved when both BTEX and $NO_3-N$ existed simultaneously. The change in soil microbial community structure was characterized by PCR-DGGE analysis comparing the relative DGGE band intensities. The band intensities of indigenous microorganisms in the soil were reduced by injecting co-culture of the three isolates. On the contrary, the relative band intensities of the isolates were increased. Among the three isolates, Pseudomonas stutzeri strain 15 rendered the highest band intensity. This indicates that the Pseudomonas stutzeri was the dominant microbial species found in the soil samples.

• Geomechanics and Engineering
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• v.23 no.4
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• pp.301-311
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• 2020

In this study, shear strength behavior of fine-grained soils was investigated under unsaturated conditions. The samples in the unsaturated state were subjected to a net normal stress (σ-u_a) of 40 kPa and different matric suctions (u_a-u_w) of 50, 100 and 150 kPa. The matric suction values applied in the triaxial tests were selected according to the bubbling pressures determined from the SWC curves. The study was carried out on prepared re-constituted cylindrical samples by uniaxial consolidation of soil slurries. First, consolidated drained (CD) triaxial compression tests were performed on the saturated samples and the cohesion and angle of internal friction were determined. After that, drained triaxial compression tests under matric suctions were performed on the unsaturated samples. In order to obtain unsaturated test results, cohesion and internal friction angle values of saturated samples were used. The nonlinear surface representing the shear strength surface was approximated consisting of two planes (double planar surface). The reason for the nonlinear behavior of some soils is that the amount of sand content contained in it is relatively high and the bubbling pressure/permanent water content value is relatively low.

• Parasites, Hosts and Diseases
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• v.59 no.4
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• pp.393-397
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• 2021

Although research conducted in East Asia has uncovered parasite eggs from ancient toilets or cesspits, data accumulated to date needs to be supplemented by more archaeoparasitological studies. We examined a total of 21 soil samples from a toilet-like structure at the Hwajisan site, a Baekje-period royal villa, in present-day Korea. At least 4 species of helminth eggs, i.e., Trichuris trichiura, Ascaris lumbricoides, Clonorchis sinensis, and Trichuris sp. (or Trichuris vulpis) were detected in 3 sediment samples of the structure that was likely a toilet used by Baekje nobles. The eggs of T. trichiura were found in all 3 samples (no. 1, 4, and 5); and A. lumbricoides eggs were detected in 2 samples (no. 4 and 5). C. sinensis and T. vulpis-like eggs were found in no. 5 sample. From the findings of this study, we can suppose that the soil-transmitted helminths were prevalent in ancient Korean people, including the nobles of Baekje Kingdom during the 5th to 7th century.