• Title/Summary/Keyword: soil materials

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Experimental Investigations of Combination Effects of Installation Damage and Creep Deformation on Long-Term Design Strength of Geogrids (지오그리드의 장기설계인장강도에 미치는 시공시 손상 및 크리프 변형 복합효과에 대한 실험적 평가)

  • Cho, Sam-Deok;Lee, Kwang-Wu;Oh, Se-Yong;Lee, Do-Hee
    • Journal of the Korean Geosynthetics Society
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    • v.4 no.4
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    • pp.23-37
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    • 2005
  • The factors affecting the long-term design strength of geogrid can be classified into factors on creep deformation, installation damage, temperature, chemical degradation and biological degradation. Especially, creep deformation and installation damage are considered as main factors to determine the long-term design strength of geogrid. Current practice in the design of a reinforced soil structures is to calculate the long-term design strength of a geosynthetic reinforcement damaged during installation by multiplying the two partial safety factors, $RF_{ID}$ and $RF_{CR}$. This method assumes that there is no evaluation of synergy effect between installation damage and creep deformation of geogrids. This paper describes the results of a series of experimental study, which are carried out to assess the combined effect of the installation damage and the creep deformation for the long-term design strength of geogrid reinforcements. A series of field tests was carried out to assess installation damage of various geogrids with respect to different fill materials, and then creep tests are conducted to evaluate the creep deformation of both undamaged and damaged geogrids. The results indicated that the tensile strength reduction factors, RF, considering the combined effect between the installation damage and the creep deformation is less than that calculated by the current design method.

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Effects of Bedding Material Composition in Deep Litter Systems on Bedding Characteristics and Growth Performance of Limousin Calves

  • Meng, J.;Shi, F.H.;Meng, Qingxiang;Ren, L.P.;Zhou, Z.M.;Wu, H.;Zhao, L.P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.1
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    • pp.143-150
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    • 2015
  • The objective of this study was to evaluate the effects of different litter mixture compositions on bedding system temperature, pH and volatile fatty acid and ammonia-N ($NH_3$-N) content, and the serum physico-chemical parameters and growth indices of calves. Thirty-two Limousin calves ($280{\pm}20kg$) were randomly assigned to four groups (n = 8 for each group) according to the bedding system used: i) control with soil only (CTR); ii) mixture with 50% paddy hulls (PH), 30% saw dusts (SD), 10% peat moss (PM) and 10% corn cobs (CC) (TRT1); iii) mixture with 15% PH, 15% SD, 10% PM, 40% CC, and 20% corn stover (CS) (TRT2); iv) mixture with 30% PH, 10% PM, 40% CC, and 20% CS (TRT3). The litter material combinations of different treatments were based on the cost of bedding system materials in China. The cost of four treatments from low to high: Control$NH_3$-N level (271.83 to 894.72 mg/kg) was lowest for TRT1 (p<0.0001) and highest for TRT2 (p<0.0001). The acetate, propionate and butyrate levels were highest for the control group (p<0.0001). In all the groups, the pH value (6.90 to 9.09) increased at the beginning and later remained stable at below 9.09. The temperature of deep litter increased at the first week and reached the maximum ($42.1^{\circ}C$) on day 38. 3,5,3'-Triiodothyronine ($T_3$) levels in the TRT1 group animals (p<0.0001) were lower than those in the control and TRT2 animals. 3,5,3',5'-Tetraiodothyronine ($T_4$) in the TRT1 group (p = 0.006) was lower than that in the other treatment groups. Cortisol (COR) in the control and TRT1 group was lower (p<0.0001) than that in the TRT2 and TRT3 groups. Corticosterone (CORt) in the control group was higher (p<0.0001) than that in the treatment groups. The findings indicate that the deep litter bedding systems provided better conditions for animal health and growth performance compared with the control system. Furthermore, the litter composition of TRT1 was found to be optimal among the three treatment groups.

Physicochemical changes and plant growth effect on composting of spent mushroom substrates (버섯수확후배지의 퇴비화에 따른 물리 화학적 변화 및 식물 생육 효과)

  • Song, Ji-Min;Phong, Nguyen Hong;Kim, Ja-Yoon;Kang, Dae-Sun;Yu, Jeong-Yeon;Kang, Hee-Wan
    • Journal of Mushroom
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    • v.18 no.3
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    • pp.268-273
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    • 2020
  • This study aimed to assess the feasibility of composting spent mushroom substrate (SMS) materials of Lentinula edodes (Le), Hericium erinaceus (He), and Pleurotus ostreatus (Po). The different SMSs were composted for 7 to 10 days at high temperatures over 50℃; the composting procedure was completed in 30 days. A maturity test was conducted using the radish seed germination index and CoMMe-100. The composted SMS (CSMS) from Le and He showed gemination indices of 130% and 81%, respectively, that satisfied the criteria of maturity standard (gemination index over 70%) and the CoMMe-100 analysis. The physicochemical changes of CSMSs included an increase in the pH range from 4-5 to 6-7, slight reduction in the EC to 1-1.4 dS/m, and an organic content of 36.9% in LeCSMS. In LeCSMS, the contents of N, P, and K were 1.2%, 2.3%, and 0.77%, respectively, and heavy metals were detected below the standard value in all CSMSs; the Ca and Mg contents in the CSMSs were increased from 30% to 60% when compared to those in the SMSs. The C/N ratio (from 26-33) in LeSMS and HeSMS decreased to 15.3-15.9 in CSMSs. The growth effect of LeCSMS treatment on pepper seedlings was 60% higher than that in the control groups, one of which was treated with commercial organic compost; the former showed a superior growth effect on the leaf width, leaf length, and leaf number compared to other control groups. In conclusion, LeCSMS and HeCSMS could be utilized as compost resources capable of efficient soil amendment and plant growth promotion.

Effect of Liquid Fertilizer Application using Fish-meal, Bone-meal and Sesame oil-cake on Seed Germination and Growth of Tomato (어분, 골분 및 참깨박을 이용한 발효액비 제조에 따른 무 발아 및 토마토 생육에 미치는 영향)

  • An, Nan-Hee;Lee, Sang-min;Cho, Jung-Rai;Lee, Cho-Rong;Kong, Min-jae
    • Journal of the Korea Organic Resources Recycling Association
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    • v.27 no.4
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    • pp.61-70
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    • 2019
  • This study aimed to investigate the physicochemical characteristics of fish meal, bone meal, and sesame oil cake, which are readily available by-products from agriculture and fisheries, during the process of liquid fertilizer fermentation, and to examine the effects of liquid fertilizer application on seed germination and growth of tomatoes. During processing the fermentation for liquid fertilizers by using fish meal, bone meal, and sesame oil cake liquid fertilizers, the pH of the fertilizer increased in the order of bone meal > fish meal > sesame oil cake, and the concentration increased rapidly up to 30 days in all types of liquid fertilizer. The nitrogen content of the liquid fertilizers increased as fermentation progressed in the order of fish meal > bone meal > sesame oil cake. The phosphorus content increased as fermentation progressed and the highest was 1.0 % in the liquid fertilizer of sesame oil cake. The germination rate and its index of radish seeds were compared for different dilutions of each of the liquid fertilizers. Excluding the 10-fold dilution of the fish meal and oil cake liquid fertilizer, all the treatment groups showed a germination rate ≥ 95 % and the germination index tended to increase with dilution rate of liquid fertilizers. For responses of tomato growth, there were no significant differences among the liquid fertilizer treatment groups; however, the organic content, microbial density, and microbial biomass C in the soil were higher than chemical fertilizer treatment. These results demonstrated that there were differences in the characteristics of liquid fertilizers depending on the materials used, and that liquid fertilizer can be used for nutrition management for the organic crop cultivation.

Comparison of bacterial communities in leachate from decomposing bovine carcasses

  • Yang, Seung Hak;Ahn, Hee Kwon;Kim, Bong Soo;Chang, Sun Sik;Chung, Ki Yong;Lee, Eun Mi;Ki, Kwang Seok;Kwon, Eung Gi
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.11
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    • pp.1660-1666
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    • 2017
  • Objective: Burial is associated with environmental effects such as the contamination of ground or surface water with biological materials generated during the decomposition process. Therefore, bacterial communities in leachates originating from the decomposing bovine carcasses were investigated. Methods: To understand the process of bovine (Hanwoo) carcass decomposition, we simulated burial using a lab-scale reactor with a volume of $5.15m^3$. Leachate samples from 3 carcasses were collected using a peristaltic pump once a month for a period of 5 months, and bacterial communities in samples were identified by pyrosequencing of the 16S rRNA gene. Results: We obtained a total of 110,442 reads from the triplicate samples of various sampling time points (total of 15 samples), and found that the phylum Firmicutes was dominant at most sampling times. Differences in the bacterial communities at the various time points were observed among the triplicate samples. The bacterial communities sampled at 4 months showed the most different compositions. The genera Pseudomonas and Psychrobacter in the phylum Proteobacteria were dominant in all of the samples obtained after 3 months. Bacillaceae, Clostridium, and Clostridiales were found to be predominant after 4 months in the leachate from one carcass, whereas Planococcaceae was found to be a dominant in samples obtained at the first and second months from the other two carcasses. The results showed that potentially pathogenic microbes such as Clostridium derived from bovine leachate could dominate the soil environment of a burial site. Conclusion: Our results indicated that the composition of bacterial communities in leachates of a decomposing bovine shifted continuously during the experimental period, with significant changes detected after 4 months of burial.

The Studies on the Removal of Harmful Microorganisms in Water by Using Antimicrobial Copper (친환경 항균성 구리의 수질 내 생물학적 오염원 제거 가능성 연구)

  • Ji, Keunho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.9
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    • pp.384-390
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    • 2018
  • Air and soil are being contaminated by the environmental pollution as a result of climate change and urbanization, resulting in water pollution reaching serious levels. In this studies, we investigated the use of antimicrobial copper for the removal of biological pollutants from water system. Specifically, we tested its effects against E. coli, B. subtilis, S. aureus, K. pneumoniae and P. aeruginosa. Made a sphere shape having a diameter of 2cm using a strip-shaped copper wire of 0.5g, 1g and 2g. And then, to confirm the antimicrobial activities, each copper ball was equipped in the broth which inoculated each pathogens. The results showed that bacterial growth of the five test bacteria was inhibited by more than 99% after reaction with a 0.5 g copper ball for at least 20 minutes. Based on the these results, if perform the further experiment such cytotoxicity, it is expected that will be enough to be used as a filter for water quality purification. The developed technique is expected to be widely applied in various industries.

Acute toxicity of lambda-cyhalothrin to Chironomus riparius in water alone and sediment-water systems (저니토독성시험법(sediment toxicity test)을 이용한 lambda-cyhalothrin의 깔따구 (Chironomus riparius)에 대한 급성독성)

  • Kim, Byung-Seok;Hamer, M.J.;Kim, Jin-Hwa;Park, Yoen-Ki;Kim, Jeong-Gu;Ahn, Young-Joon
    • The Korean Journal of Pesticide Science
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    • v.3 no.1
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    • pp.57-65
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    • 1999
  • The midge Chironomus riparius is a member of widespread dipteran insect which has been used for sediment toxicity test. The 2nd-3rd larvae Chironomus riparius were exposed to $^{14}C$-lambda-cyhalothrin in laboratory water only system(A) and sediment-water system(B) at $20{\pm}2^{\circ}C$. The concentration was nominally in the range of 0.16 to $20{\mu}g/{\ell}$ and 62.5 to 8000 ${\mu}g/kg$, respectively. System(A) was prepared by applying the chemical to 250 ml water and introducing Chironomus riparius larvae into the system(day 0). System(B) was prepared by applying the chemical to the 25 g of soil and 250 ml water and shaking and rolling them for two hours. After allowing the system to settle for two days, Chironomus riparius larvae were introduced into the system. After 72 hours, the two systems were terminated and dead larvae were observed. The measurement of residue in water was conducted at the start(day 0) and the end of the study(day 3). The residue of $^{14}C$-lambda-cyhalothrin in water was accounted for approximately 65% of nominal concentration in system(A) and $0.2{\sim}0.4%$ in system) on 3 days. $LC_{50}$ was less than $0.156{\mu}g/{\ell}$ in system(A) and 889 ${\mu}g/kg$ in system(B), based on the nominally applied concentration.

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Effect of KOH Concentrations and Pyrolysis Temperatures for Enhancing NH4-N Adsorption Capacity of Rice Hull Activated Biochar (KOH 농도 및 탄화온도가 왕겨 활성 바이오차의 NH4-N 흡착능 향상에 미치는 영향)

  • Kim, HuiSeon;Yun, Seok-In;An, NanHee;Shin, JoungDu
    • Korean Journal of Environmental Agriculture
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    • v.39 no.3
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    • pp.171-177
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    • 2020
  • BACKGROUND: Recently, biomass conversion from agricultural wastes to carbon-rich materials such as biochar has been recognized as a promising option to maintain or increase soil productivity, reduce nutrient losses, and mitigate greenhouse gas emissions from the agro-ecosystem. This experiment was conducted to select an optimum conditions for enhancing the NH4-N adsorption capacity of rice hull activated biochar. METHODS AND RESULTS: For deciding the proper molarity of KOH for enhancing its porosity, biochars treated with different molarity of KOH (0, 1, 2, 4, 6, 8) were carbonized at 600℃ in the reactor. The maximum adsorption capacity was 1.464 mg g-1, and an optimum molarity was selected to be 6 M KOH. For the effect of adsorption capacity to different carbonized temperatures, 6 M KOH-treated biochar was carbonized at 600℃ and 800℃ under the pyrolysis system. The result has shown that the maximum adsorption capacity was 1.76 mg g-1 in the rice hull activated biochar treated with 6 M KOH at 600℃ of pyrolysis temperature, while its non-treated biochar was 1.17 mg g-1. The adsorption rate in the rice hull activated biochar treated with 6 M KOH at 600℃ was increased at 62.18% compared to that of the control. Adsorption of NH4-N in the rice hull activated biochar was well suited for the Langmuir model because it was observed that dimensionless constant (RL) was 0.97 and 0.66 at 600℃ and 800℃ of pyrolysis temperatures, respectively. The maximum adsorption amount (qm) and the bond strength constants (b) were 0.092 mg g-1 and 0.001 mg L-1, respectively, for the rice hull activated biochar treated with 6 M KOH at 600℃ of pyrolysis. CONCLUSION: Optimum condition of rice hull activated biochar was 6M KOH at 600℃ of pyrolysis temperature.

Geochemical Modeling of Groundwater in Granitic Terrain: the Yeongcheon Area (영천 화강암지역 지하수의 지화학적 모델링)

  • Koh, Yong-Kwon;Kim, Chun-Soo;Bae, Dae-Seok;Yun, Seong-Taek
    • Journal of the Korean Society of Groundwater Environment
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    • v.5 no.4
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    • pp.192-202
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    • 1998
  • We investigated the geochemistry and environmental isotopes of granite-bedrock groundwater in the Yeongcheon diversion tunnel which is located about 300 m below the land surface. The hydrochemistry of groundwaters belongs to the Ca-HCO$_3$type, and is controlled by flow systems and water-rock interaction in the flow conduits (fractures). The deuterium and oxygen-18 data are clustered along the meteoric water line, indicating that the groundwater are commonly of meteoric water origin and are not affected by secondary isotope effects such as evaporation and isotope exchange. Tritium data show that the groundwaters were mostly recharged before pre-thermonuclear period and have been mixed with younger surface water flowing down rapidly into the tunnel along fractured zones. Based on the mass balance and reaction simulation approaches, using both the hydrochemistry of groundwater and the secondary mineralogy of fracture-filling materials, we have modeled the low-temperature hydrogeochemical evolution of groundwater in the area. The results of geochemical simulation show that the concentrations of Ca$\^$2+/, Na$\^$+/ and HCO$_3$and pH of waters increase progressively owing to the dissolution of reactive minerals in flow paths. The concentrations of Mg$\^$2+/ and K$\^$+/ frist increase with the dissolution, but later decrease when montmorillonite and illitic material are precipitated respectively. The continuous adding of reactive minerals, namely the progressively larger degrees of water/rock interaction, causes the formation of secondary minerals with the following sequence: first hematite, then gibbsite, then kaolinite, then montmorillonite, then illtic material, and finally microcline. During the simulation all the gibbsite is consumed, kaolinite precipitates and then the continuous reaction converts the kaolinite to montmorillonite and illitic material. The reaction simulation results agree well with the observed, water chemistry and secondary mineralogy, indicating the successful applicability of this simulation technique to delineate the complex hydrogeochemistry of bedrock groundwaters.

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Effect of Commercial Organic :Medium Amended with Vermicast on the Growth of Rice Seedlings(Oryza sativa L.) -Amended with Vermicast of Oyster Mushroom Waste- (지렁이 분립을 첨가한 유기상토가 벼의 유식물체 생육에 미치는 영향 -느타리버섯 폐배지로 생산한 분립의 첨가-)

  • Lee, Ju-Sam;Kim, In-Soo
    • Korean Journal of Organic Agriculture
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    • v.17 no.1
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    • pp.55-62
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    • 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.

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