Appropriate Soil Heat Treatment Promotes Growth and Disease Suppression of Panax notoginseng by Interfering with the Bacterial Community

( Ying-bin Li ),( Zhi-ping Zhang ),( Ye Yuan ),( Hui-chuan Huang ),( Xin-yue Mei ),( Fen Du ),( Min Yang ),( Yi-xiang Liu ),( Shu-sheng Zhu ) 한국미생물 · 생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.3

In our greenhouse experiment, soil heat treatment groups (50, 80, and 121°C) significantly promoted growth and disease suppression of Panax notoginseng in consecutively cultivated soil (CCS) samples (p < 0.01), and 80°C worked better than 50°C and 121°C (p < 0.01). Furthermore, we found that heat treatment at 80°C changes the microbial diversity in CCS, and the inhibition ratios of culturable microorganisms, such as fungi and actinomycetes, were nearly 100%. However, the heat-tolerant bacterial community was preserved. The 16S rRNA gene and internal transcribed spacer (ITS) sequencing analyses indicated that the soil heat treatment had a greater effect on the Chao1 index and Shannon’s diversity index of bacteria than fungi, and the relative abundances of Firmicutes and Proteobacteria were significantly higher than without heating (80 and 121°C, p < 0.05). Soil probiotic bacteria, such as Bacillus (67%), Sporosarcina (9%), Paenibacillus (6%), Paenisporosarcina (6%), and Cohnella (4%), remained in the soil after the 80°C and 121°C heat treatments. Although steam increased the relative abundances of most of the heat-tolerant microbes before sowing, richness and diversity gradually recovered to the level of CCS, regardless of fungi or bacteria, after replanting. Thus, we added heat-tolerant microbes (such as Bacillus) after steaming, which reduced the relative abundance of pathogens, recruited antagonistic bacteria, and provided a long-term protective effect compared to the steaming and Bacillus alone (p < 0.05). Taken together, the current study provides novel insight into sustainable agriculture in a consecutively cultivated system.

건설잔토의 활성도 증진을 위한 가열효과에 관한 연구

박상우 ( Park Sang-woo ),장철현 ( Jang Cheol-hyeon ) 한국환경기술학회 2000 한국환경기술학회지 Vol.1 No.1

본 연구는 건설잔토을 가열처리 하였을때의 활성도 증진여부와 가열처리된 시료에 첨가제를 첨가 하였을때의 압축강도 증진효과에 관해 연구하였다. 실험 결과 활성도를 나타내는 하소조건은 500℃에서 60분ㆍ120분, 600℃에서 30분ㆍ60분, 700℃에서 30분으로 나타났다. 활성도를 보이는 조건에서의 첨가제별 첨가에 따른 압축강도는 600℃-30분에서 가열처리한 시편에 대해 NaOH 5% 첨가시 폐토(WS)에서 53.7kg/cm², 굴착토(GS)에서 24.3kg/cm²을 나타냈다. 반면에 가열처리하지 않은 시편에 첨가제를 첨가한 시편은 수침시 붕괴되어 압축강도를 나타내지 못하였다. Heating effect on advancement of activity for wasted soils, wasted from the quarry Mines(WS) and the digging works(GS), has been examined. The conditions of Heat-treatment involved the two factors. The first was the temperature of heat-treatment At four different temperatures(400℃, 500℃, 600℃, and 700℃). The second was the Duration of heating with 15^min, 30^min, 60^min, and 120^min. The heat-treated soils were compacted with water(10%) and binders(NaOH, Na₂SiO₃) in the harvard miniature compaction mould. The Compacted soils were immersed under water for 24hours after air-cured for 28days. The samples were subject to compressive strength. The results showed that the compressive strength of these soils generally increased With increasing the calcination temperature and duration time. It appeared that the optimum condition for heat-treatment of these soils was 600℃ for 30min. The maximum compressive strength 53.7kg/cm², after 24hours immersion under water has been developed in the sample of wasted soil(WS) when 5.0% NaOH was a added as a binded.

Effect of Heat Treatment of the Clayey Soils on the shear strength with use of sodium silicate

Lim, Nam-Woong 중앙대학교 건설산업기술연구소 2002 건설산업기술연구소 논문집 Vol.3 No.-

The two type of clayey soils activated thermally at 500℃ for 15 and 60 minutes (as the residual time) were mixed with sodium silicate(Na_2SiO_3) at a concentration of five percent by weight of the sample. The mixture was compacted with pressure to form the cylindrical specimens. After 7 days room curing, these sample were subjected to a triaxial strength. The composition of the reaction products with Na_2SiO_3 were examined by X-Ray Diffraction(XRD) and Scanning Electron Microscopy(SEM) The results indicated that the clayey soils activated thermally for 60 minutes had greater strength and more extensive formation of crystalline reaction products than that of 15 minutes. The resultant crystalline products appear to be polymorphic varieties of zeolite minerals, which constitute a complex of Na-Al-Si-Fe-Ca-Mg, but contained as appreciable amount of iron ions in their structure. Substitution of Fe^+++ for Al^+++ his suggested due to the thermal weakening of the alumina-silica structural bond of clay lattice.

소성 준설토의 포졸란 반응성에 대한 기초 연구

김지현,문훈,정철우,이재용 한국건축시공학회 2014 한국건축시공학회지 Vol.14 No.6

Recently, the amounts of dredge sea soil in south Korea have been increasing because of various maintenanceworks at harbors and rivers. Dredged sea soil contains various contaminants. Hence, prior to recycling the dredged seasoil, the various contaminants should be removed to prevent a secondary contamination due to the leaching ofhazardous chemicals. Pretreated dredged sea soil can be buried under the ground or used for land reclamation. In thisstudy, however, pretreated dredged sea soil was used to investigate the level of pozzolanic activity. The properties ofpretreated dredged sea soil were investigated, the method for heat treatment was determined, and the compressivestrength of mortar using dredged sea soil was examined. According to the XRF result, the main components ofdredged sea soil were SiO2 of over 55%, and Al2O3 and SO3 of some amounts. Results from XRD and TG/DTAshowed that pretreated dredged sea soil can be used as a pozzolanic material. When dredged sea soil was thermallytreated for 90 min at 550℃, a compressive strength result was similar to that of control mortar. 최근 국내에서는 항만 및 하천의 각종 정비 사업으로 인해 많은 양의 준설토가 발생하고 있으며, 그 중 해양 준설토의 경우 다양한 오염물질을 포함하고 있는 것으로 조사되고 있다. 하지만 이와 같이 전처리 과정 없이 재활용될경우, 지반의 2차 오염의 문제를 야기할 것으로 우려되고있다. 일반적으로 해양준설토의 경우 지반에 매립되는 성토와 같은 형태로의 재활용이 대부분이다. 그러므로 본 연구에서는 해양준설토의 기초적 물성을 확인하고 소성에 따른 포졸란 반응성을 평가하여 포졸란재로써의 활용가능성에 관한 기초자료를 제시하였다. 결과에 따르면 XRF 분석을 통해 측정된 해양준설토의 주성분은 55% 이상이 SiO2인 것으로 나타났다. XRD 및 TG/DTA 분석결과 100㎛준설토의 경우 결정구조의 변화가 발생하여 포졸란재로써적용 가능성이 일부 확인되었다. 추가로 압축강도를 측정한 결과 550℃에서 90min 열처리한 준설토의 경우 평균압축강도가 35.55MPa로 Plain과 유사하게 측정되었다. 따라서 550℃ 온도에서 90min 동안 소성과정을 거친 100㎛ 준설토의 경우, 포졸란 반응성이 가장 높은 것으로 사료된다.

감귤박 기반 토양피복재의 기능성 강화 후처리 연구

이유진,김소현,신명석,김정은,성용주 한국펄프·종이공학회 2024 펄프.종이기술 Vol.56 No.2

. This study investigated the application effects of biodegradable coatings and surface heat treatment to improve the properties of citrus peel soil covering materials used in landscaping and horticulture, aiming to enhance the utilization of citrus by-products. Various coating methods including soaking, roll-coating, and spray coating were applied to address the uneven surface structure of citrus peel soil covering materials. The spray coating method showed the relatively uniform coating results and provided the accurate control of coating amount adjustment. The effects of biodegradable coatings such as starch, acrylic-based coatings, and rosin emulsions were compared and evaluated, revealing that the starch coating exhibited the highest increase in strength while the acrylic-based coating was most effective in enhancing water resistance. It was observed that increasing the number of spray coating times could increase the strength and the resistance to water disintegration. It was possible to increase the coating amount depending on the number of spray coating times, leading to improvements in strength and he resistance to water disintegration. Surface heat treatment using direct flame was conducted, resulting in increased the resistance to water disintegration through surface carbonization. Through these surface coating and treatment methods, this study confirmed the potential for improving the quality and functionality of citrus peel soil covering materials, providing foundational data for the production of functional citrus peel soil covering materials.

Frost Damage Improvement for Railway Subgrade Based on Ground Temperature Control in Cold Regions

Junyun Zhang,Zhuoling He,Jun Feng 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.8

Due to the ignorance of the influence of frozen soil during the design period, the frost damage of subgrade in Datong-Junggar Railway was serious. The improvement scheme of frost damage was researched. However, the research based on the existing project was few, and previous improvement schemes could have an impact on the normal operation of railway system. Datong-Junggar Railway has undertaken the important task of transporting coal resources for China since its normal operation. To ensure normal operation of existing railway, the heating hole scheme was investigated by finite element simulations. The embedding spacing, the heating hole temperature and the embedding depth were analyzed. Based on the simulated results and on-site conditions, the design scheme of the heating hole (embedding spacing: 1.0 m, the heating hole temperature: 30°C and embedding depth: 70 cm) was proposed. Finally, the on-site monitoring in Qianshimen was taken to verify the feasibility of the heating hole scheme. Under the continuous energizing condition, the ground temperature remained basically stable even though the temperature had dropped to -7oC. The research results could enrich the design schemes for frost damage in cold regions from the aspect of ground temperature control.

Effects of Heating on the Formation of Black Humic Acids

Naoya Katsumi,Koyo Yonebayashi,Masanori Okazaki 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

순환골재 제조공정에서 발생한 슬러지의 지반개량형 고화제 활용에 관한 연구

성진경 ( Jin Kyeong Soung ),김순호 ( Soon Ho Kim ),배원태 ( Won Tae Bae ),전명훈 ( Myung Hoon Jun ) 한국폐기물자원순환학회(구 한국폐기물학회) 2006 한국폐기물자원순환학회지 Vol.23 No.5

제사속도와 열처리에 따른 polylactic acid 섬유의 물성 및 생분해성 변화

박정희,홍은영 한국의류학회 2006 한국의류학회지 Vol.30 No.4