• Title/Summary/Keyword: soil medium

Search Result 1,497, Processing Time 0.033 seconds

Biofortification of mushroom (Pleurotus floridanus) using calcium based supplements

  • Odiketa, J.K;Whitehall, S.;Adedokun, O.M.
    • Journal of Mushroom
    • /
    • v.18 no.4
    • /
    • pp.287-291
    • /
    • 2020
  • The nutritional value and yield of mushrooms depend on the substrate on which it is grown. This study sought to biofortify Pleurotus floridanus with calcium supplements and assess its effect on the yield and calcium levels. The experiment was set up in a 2 × 5 factorial and replicated thrice in a completely randomized design. Two calcium supplements, OML and OMW, were added to two growth media. The examination of total dry weight yield showed that calcium supplements OML and OMW in the sawdust medium containing wheatbran in the ratio 1:10 had a mean value of 4.37 g, which was significantly higher (P < 0.05) than that in the control (1.29 g). However, in the sawdust-only medium, there was no significant difference (p > 0.05) in the application of treatments. No significant difference (p > 0.05) was observed between the calcium types in both growth media. The mineral analysis showed that calcium levels were increased in harvested mushrooms with the addition of calcium OML and OMW to the growth media.

Failure mechanisms in coupled poro-plastic medium

  • Hadzalic, Emina;Ibrahimbegovic, Adnan;Nikolic, Mijo
    • Coupled systems mechanics
    • /
    • v.7 no.1
    • /
    • pp.43-59
    • /
    • 2018
  • The presence of the pore fluid strongly influences the reponse of the soil subjected to external loading and in many cases increases the risk of final failure. In this paper, we propose the use of a discrete beam lattice model with the aim to investigate the coupling effects of the solid and fluid phase on the response and failure mechanisms in the saturated soil. The discrete cohesive link lattice model used in this paper, is based on inelastic Timoshenko beam finite elements with enhanced kinematics in axial and transverse direction. The coupling equations for the soil-pore fluid interaction are derived from Terzaghi's principle of effective stresses, Biot's porous media theory and Darcy's law for fluid flow through porous media. The application of the model in soil mechanics is illustrated through several numerical simulations.

Bioavailability of sorbed phenanthrene in soil slurries (토양 슬러리내에 수착된 phenanthrene의 생물학적 이용성)

  • 신원식;김영규;김영훈;송동익
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • 2002.09a
    • /
    • pp.92-95
    • /
    • 2002
  • Bioavailability study was conducted to elucidate the relationship between sorption/desorption and biodegradation of sorbed phenanthrene in seven different soils. Mineralization kinetics was determined for phenanthrene-sorbed soil slurries inoculated with Pseudomonas putida (ATCC strain 17484). Two biodegradation models were used to fit mineralization kinetics; (i) a first-order degradation model and (ii) a coupled degradation-desorption model. The biodegradation rates were in order of vermicompost >Bion peat > 50% organoclay > Pahokee > blank (no soil, medium only) > montmorillonite > Ohio shale. The mineralization rate constants increased as desorption-resistance of phenanthrene increased. Among the tested sorbents, active biodegradation of phenanthrene was observed in vermicompost and Bion peat. Biodegradation in these two sorbents exhibited little lag time and a high maximum mineralized capacity. The role of sorption/desorption in bioavailability of phenanthrene sorbed in soils was discussed.

  • PDF

BIO-BARRIER FORMAT10N BY BACTERlUM/FUNGUS INJECTION INTO SOILS

  • Kim, Geonha
    • Proceedings of the Korean Environmental Health Society Conference
    • /
    • 2001.11a
    • /
    • pp.11-16
    • /
    • 2001
  • If microorganisms are injected into porous medium such as soils along with appropriate substrate and nutrients, soil pore size and shape are changed from the initial condition as a result of biofilm formation, which make hydraulic conductivity reduced. In this research, hydraulic conductivity reduction was measured after specific bacterium or fungus was inoculated into soil pore. Hydraulic conductivity was decreased to 10 % ∼ 1 % and maintained constant while substrate was provided. Under the adverse conditions such as no substrate, chemical solution permeation, and freeze-thaw cycles, hydraulic conductivity was increased 30∼50%. Hydraulic conductivity decrease of fungus-soil mixture was faster than that of bacterium-soil mixture. Fungus-soil mixture, however, was more sensitive to the adverse conditions.

  • PDF

Earthquake Response Analysis of Soil-Structure Interaction Systems considering Nonlinear Soil Behavior (지반의 비선형을 고려한 지반-구조물 상호작용계의 지진응답해석)

  • 이종세;최준성;임동철
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2000.10a
    • /
    • pp.361-368
    • /
    • 2000
  • This paper demonstrates how nonlinear soil behavior in a soil-structure interaction system can be realistically incorporated by using a hybrid method in a nonlinear time-domain analysis. The hybrid method employs a general-purpose nonlinear finite element program coupled with a linear SSI program for the unbounded layered soil medium In order to verify the validity and applicability of the hybrid method, nonlinear earthquake response analyses are carried out for the Hualien free-field problem, in which the ground and underground accelerations were measured during several earthquake events, and for a 2-D subway station. It is found that the nonlinear earthquake responses predicted for the Hualien free-field using the hybrid method compare very well with the observed responses whereas the subway station example gives reasonable results.

  • PDF

Dynamic testing of a soil-steel bridge

  • Beben, Damian;Manko, Zbigniew
    • Structural Engineering and Mechanics
    • /
    • v.35 no.3
    • /
    • pp.301-314
    • /
    • 2010
  • The paper presents the results and conclusions of dynamic load tests that were conducted on a road bridge over the Mokrzyca river in Wroclaw (Poland) made of galvanized corrugated steel plates (CSP). The critical speed magnitudes, velocity vibration, vibration frequency were determined in the paper. The dynamic analysis is extremely important, because such studies of soil-steel bridges in the range of dynamic loads are relatively seldom conducted. Conclusions drawn from the tests can be most helpful in the assessment of behaviour of this type of corrugated plate bridge with soil. In consideration of application of this type of structure in the case of small-to-medium span bridges, the conclusions from the research will not be yet generalized to all types of such solutions. The detailed reference to all type of such bridge structures would be requiring additional analysis (field tests and calculations) on the other types of soil-steel bridges.

PGA estimates for deep soils atop deep geological sediments -An example of Osijek, Croatia

  • Bulajic, Borko D.;Hadzima-Nyarko, Marijana;Pavic, Gordana
    • Geomechanics and Engineering
    • /
    • v.30 no.3
    • /
    • pp.233-246
    • /
    • 2022
  • In this study, the city of Osijek is used as a case study area for low to medium seismicity regions with deep soil over deep geological deposits to determine horizontal PGA values. For this reason, we propose new regional attenuation equations for PGA that can simultaneously capture the effects of deep geology and local soil conditions. A micro-zoning map for the city of Osijek is constructed using the derived empirical scaling equations and compared to all prior seismic hazard estimates for the same area. The findings suggest that the deep soil atop deep geological sediments results in PGA values that are only 6 percent larger than those reported at rock soil sites atop geological rocks. Given the rarity of ground motion records for deep soils atop deep geological layers around the world, we believe this case study is a start toward defining more reliable PGA estimates for similar areas.

Concentration Characteristics of PCBs in Pine Needle and Soil at Rural Area (교외지역에서 소나무 잎과 토양 중 PCBs의 농도 특성)

  • Shin Eun-Sang;Yeo Hyun-Gu
    • Journal of environmental and Sanitary engineering
    • /
    • v.21 no.1 s.59
    • /
    • pp.1-11
    • /
    • 2006
  • This study was to investigate concentration characteristics of atmospheric PCBs in soil sample and pine needle at rural area. Profiles of PCB congener detected in pine needle and soil sample have a difference that low molecular PCBs mainly existed in pine needle, whereas high molecular PCBs were mainly existed in soil sample because of their different vapor pressure and octanol-air partitioning coefficient($K_{OA}$) of each congeners. Correlation coefficients(r) of PCB congeners simultaneously detected in soil and pine needle were significant (r>0.71, p<0.01), which showed that PCB congeners patterns of atmosphere could be estimated in using pine needle and soil sample indirectly. The contributions(%) of higher molecular PCBs(>penta-CB) to total PCBs in soil sample were higher than those of pine needle and the contribution of lower molecular PCBs(

Physico-Chemical Properties of Soils at the Ground of Landscape Planting in Reclaimed Land from the Sea (임해매립지의 식재지반별 토양 물리·화학적 특성)

  • Kim, Do-Gyun
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.4 no.4
    • /
    • pp.12-18
    • /
    • 2001
  • This study was carried out to analyze physico-chemical properties of soils at the ground of landscape planting in reclaimed land from the sea on Kwangyang Bay, South Korea. Physico-chemical properties of soils at each planting grounds were tested by ANOVA and were significantly(P<0.01) different. The difference came from the soil properties of the covered soil, the disturbance applied to the soil with land use and the accumulation of organic matter after landscape planting. Soil hardness, pH, ECe, Na and K level were in a stable condition at high then low of ground height for landscape planting. Organic matter accumulation was greater at lower planting grounds then top and slope ground of big mounding. The planting grounds of favorable growth for landscape trees were determined as following order : the slope ground and the top ground of big mounding>the ground of medium mounding>the coved ground of improve soil>the lower ground of big mounding>the filled ground of improve soil.

  • PDF

Vegetation and Soil Properties of the Young-bong Area in Woraksan National Park (월악산국립공원 영봉지역의 식생과 토양특성)

  • Shin, Kyounghyoun;Kwon, Hyejin;Song, Hokyung
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.14 no.1
    • /
    • pp.43-55
    • /
    • 2011
  • This study was carried out to analyze vegetation, soil characteristic, and ordination of the Young-bong region in Woraksan National Park. Communities by species in Woraksan forest were composed of Quercus mongolica community group. This community group was classified into Pinus densiflora community, Quercus variabilis community, Carpinus cordata community and Quercus mongolica community. In the study, it was found that the composition of organic matter was 9.6~19.6%, nitrogen (0.3~0.7%), available phosphorous (4.5~8.8mg/kg), exchangeable K ($0.3{\sim}0.5cmol^+/kg$), exchangeable Ca ($1.6{\sim}6.75cmol^+/kg$), exchangeable Mg ($0.8{\sim}1.55cmol^+/kg$), cation exchange capacity (C.E.C.; $7.6{\sim}32.95cmol^+/kg$), and pH was 4.5~5.1 respectively. The Carpinus cordata community were mostly found in high elevation and high percentage of total nitrogen, C.E.C., and organic matter. Controversially, Pinus densiflora community and Quercus variabilis community were found mostly in low elevation and low percentage of total nitrogen, C.E.C., and organic matter. The Quercus mongolica community were found in medium elevation and medium percentage of total nitrogen, C.E.C., and organic matter.