Impacts of Soil Microbial Populations on Soil Chemical and Biological Properties under Tropical Dry Evergreen Forest, Coromandel Coast, India

Sudhakaran M,Ramamoorthy D,Swamynathan B,Ramya J 강원대학교 산림과학연구소 2014 Journal of Forest Science Vol.30 No.4

There are very few studies about soil chemical and biological properties under tropical dry evergreen forest Coromandel Coast, India. The present study was conducted in six tropical dry evergreen forests sites such as Oorani, Puthupet, Vadaagram, Kotthatai, Sendrakillai and Palvathunnan. We measured the quantity of soil chemical, biological properties and selected soil microorganisms for investigating the impacts of soil microbial populations on soil chemical and biological properties. The result showed that total N, P, Ca, S, Fe, Mn, Cu, Co, exchangeable K, Olson P, extractable Ca and phosphobacterial population were higher in the soil from Kothattai forest site. Organic carbon, total Mg, extractable Na, soil respiration, β-glucosidase activity, bacterial population, fungi population and actinomycetes population were higher in the soil from Palvathunn forest site. Total K, NH4 +-N, NO3 −-N, exchangeable K, extractable Ca, extractable Na, azotobacter population, bacillus population and rhizobacteria population were higher in the soil from Sendrakillai. Beijerinckia population, rhizobacteria and soluble sodium were higher in Puthupet forest soil. Total Si, total Na and exchangeable K were higher in soil from Oorani forest site. Total Mo and exchangeable K were higher in the soil from Vadaagaram forest site. The results showed that organic carbon, total N, NH4 +-N, NO3 −-N, extractable P, extractable Ca, soil respiration and β-glucosidase were significantly correlated with soil microbial populations. Therefore soil microorganisms are important factor for maintaining soil quality in tropical dry evergreen forest.

A basic research on correlation analysis of electrical-chemical-mechanical characteristics for estimating mechanical properties

Yong-Seok Lee(이용석) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11

The materials properties are very important not only for research but also for industries that use various materials. Many industries and researchers have tried to measure materials properties. However, most of the research on materials properties have been conducted by focusing on only one characteristic. In hence, it is difficult to discover the correlation between each characteristic of the material. The electrical-chemical-mechanical properties of materials appear characteristics based on the atomic structure of materials. If the atomic structure is changed, the electrical, chemical, and mechanical properties will be effected and are expected to correlation among them. Therefore, we propose basic experiments that can analyze the correlation among electrical-chemical-mechanical properties for predicting mechanical properties of new materials in this research.

Calculating Soil Quality Index for Biomass Production Based on Soil Chemical Properties

김성철,홍영규,이상필,오승민,임경재,양재의 한국토양비료학회 2017 한국토양비료학회지 Vol.50 No.1

Soil quality has been regarded as an important factor for maintaining sustainability of ecosystem. Main purpose ofthis research was i) to select minimum factor for predicting biomass, and ii) to calculate soil quality index forbiomass according to soil chemical properties. Result showed that soil pH, electrical conductivity (EC), soilorganic matter (SOM), cation exchange capacity (CEC), and available phosphorus are minimum data set forcalculating biomass production in soil. Selected representative soil chemical properties were evaluated for soilquality index and rated from 1 to 5 (1 is the best for biomass production). Percentage of each grade in terms ofbiomass production in national wide was 14.52, 35.23, 33.03, 6.47, 10.75% respectively. Although, only soilchemical properties were evaluated for calculating optimum soil quality, result of this research can be useful tounderstand basic protocol of soil quality assessment in national wide.

Changes of Soil Physico-Chemical Properties by Soil Loss of Bare Condition Using Slope Lysimeter

이세인,옥정훈,손정우,황선아,오부영,허승오 한국토양비료학회 2022 한국토양비료학회지 Vol.55 No.4

This study was carried out to investigate the soil properties of bare soil and analyzed the correlation betweensoil loss and physico-chemical properties using slope lysimeter (13% slope). The texture of experiment plotswas prepared with clay loam (CL) and sandy loam (SL). Soil samples were collected of top soil (0 - 20 cm) andsub soil (20 - 40 cm) in each sampling sites (top: 5.0 m; middle: 12.0 m; bottom: 19.0 m) of experiments plotsfrom 2019 to 2021. Total soil loss over 3 years was 88.5 and 154.7 ton ha-1 for the CL and SL, respectively,which was higher in SL than CL. For the soil physical properties, there was an annual difference for the bulkdensity and porosity of the sub soil. However, there was no difference in the changes of sampling sites forboth properties. For the soil chemical properties, there were differences in the changes of year and samplingsites for the pH, EC, organic matter content, available phosphate, and exchangeable potassium of the top soil. However, there was not a clear tendency of change of soil chemical properties, which had relatively lowerthan the optimum range of upland soil in Korea. Among soil chemical properties, accumulated soil loss wasnegatively correlated with soil organic matter content for the CL and SL. The coefficient of determination (r2)of the accumulated soil loss and the mean values of total organic matter content was 0.78 and 0.65, respectively,for the CL and SL. Especially, the correlation between the accumulated soil loss and the organic matter contentby sampling sites was the highest in the top of experiment plots for the CL (r2= 0.82, p = 0.001) and in themiddle of experiment plots for the SL (r2= 0.99, p < 0.001). The results of this study contribute to a furtherunderstanding on the soil characteristics by soil loss.

Relationship between Soil Management Methods and Soil Chemical Properties in Protected Cultivation

강윤임,이인복,박진면,강용구,김승희,고현석,권준국 한국환경농학회 2009 한국환경농학회지 Vol.28 No.4

Various cultural practices have been promoted as management options for enhancing soil quality and health. The use of soil management methods can cause changes in fertility by affecting soil chemical properties. This study aims to evaluate interactions between soil chemical properties and soil management methods in protected cultivation, and to classify soil management methods that similarly affect soil chemical properties. Water-logging and irrigation reduced soil pH and Av.P2O5 content. Application of animal manures has a positive effect on levels of organic matter, Av.P2O5, K, Zn, and Cu. The ECs tend to be low in the application of organic amendments, including rice residues and wood residues. Deeper plowing caused a reduction in Ca content. Practicing soil nutrient-considering fertilization and fertigation did not exert an influence on nutrient element contents. In cluster analysis of the soil management methods according to major nutrients, low similarities were found with deeper plowing and crop rotation with rice in comparison with other practices. In minor nutrient characteristics, crop rotation and application of animal manures and rice residues were linked at a high Ward’s distance, while other practices were found to be relatively low distinct. Each soil management method has a similar or different effect on soil chemical properties. These results suggest the necessity of establishing limits and standards according to the effects of soil management methods on soil chemical properties for economic soil practices

Relationship between Soil Management Methods and Soil Chemical Properties in Protected Cultivation

( Yun Im Kang ),( In Bog Lee ),( Jin Myeon Park ),( Yong Gu Kang ),( Seung Heui Kim ),( Hyeon Seok Ko ),( Joon Kook Kwon ) 한국환경농학회 2009 한국환경농학회지 Vol.28 No.4

Various cultural practices have been promoted as management options for enhancing soil quality and health. The use of soil management methods can cause changes in fertility by affecting soil chemical properties. This study aimed to evaluate interactions between soil chemical properties and soil management methods in protected cultivation, and to classify soil management methods that similarly affect soil chemical properties. Water-logging and irrigation reduced soil pH and available P2O5 content. Application of animal manures has a positive effect on levels of organic matter, Av.P2O5, K, Zn, and Cu. The electrical conductivites tened to be low in the application of organic amendments, including rice and wood residues. Deeper plowing caused a reduction in Ca content. Practicing soil nutrient-considering fertilization and fertigation did not exert an influence on nutrient element contents. In a cluster analysis of the soil management methods according to major nutrients, low similarities were found with deeper plowing and crop rotation with rice in comparison with other practices. In a cluster analysis by minor nutrient characteristics, crop rotation and application of animal manures and rice residues were linked at a high Ward`s distance, while other practices were found to be relatively low distinct. Each soil management method has a similar or different effect on soil chemical properties. These results suggest the necessity of establishing limits and standards according to the effects of soil management methods on soil chemical properties for economic soil practices.

Chemical evolution-induced strengthening on AlCoCrNi dual-phase high-entropy alloy with high specific strength

Jumaev, Elyorjon,Hong, Sung Hwan,Kim, Jeong Tae,Park, Hae Jin,Kim, Young Seok,Mun, Sang Chul,Park, Jun-Young,Song, Gian,Lee, Jong Kook,Min, Byung Ho,Lee, Taegyu,Kim, Ki Buem Elsevier 2019 JOURNAL OF ALLOYS AND COMPOUNDS Vol.777 No.-

<P><B>Abstract</B></P> <P>Quaternary AlCoCrNi alloy was designed by removing the heavy constituent of Fe from the dual-phase AlCoCrFeNi high-entropy alloy to achieve low density with good mechanical properties. The AlCoCrNi alloy exhibited a nano-scale dual-phase structure consisted of Cr-rich A2 and Ni(Co)-Al-rich B2 phases with a high degree of coherence in both dendritic and interdendritic regions. In particular, the Ni(Co)-Al-rich B2 phase revealed the non-stoichiometric composition between the Ni and the Al, which deviated with the Ni-Al-rich B2 phase with a stoichiometric composition in the previous AlCoCrFeNi high-entropy alloy. The chemical evolution in the constituent phases strongly affected the mechanical properties of the dual-phase high-entropy alloy. Based on these microstructural features of the AlCoCrNi alloy, the mechanical properties were systematically investigated at wide temperature ranges.</P> <P><B>Highlights</B></P> <P> <UL> <LI> AlCoCrNi alloy is designed by modulating from the AlCoCrFeNi HEA. </LI> <LI> Nano-scaled Cr-rich A2 and Ni(Co)Al-rich B2 phases are formed in ID and DR regions. </LI> <LI> The Ni(Co)Al-rich B2 phase exhibits non-stoichiometric composition between Ni and Al. </LI> <LI> The chemical evolution on B2 phase induces a strengthening of the AlCoCrNi alloy. </LI> <LI> The alloy with a low density of 6.9 gcm<SUP>−3</SUP> reveals superior specific strength at wide temperature ranges. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

화학 첨가제와 밀가루의 열처리가 제빵 특성에 미치는 효과

이지은,고봉경 한국조리과학회 2004 한국식품조리과학회지 Vol.20 No.2

Effects of various chemical additives and heat treatments were investigated on the wheat flour doughs and breads. Ammonium ferric citrate, Ca-citrate, CaCl_(2), FeSO_(4), MgCl_(2) and ZnO were mixed respectively to the flour up to 0.1% of flour dry weight basis. Ammonium ferric citrate and ferric sulfate showed no significant effects on the dough properties and magnesium sulfate, calcium chloride and zinc oxide increased elastic properties and optimum dough mixing time. However, calcium citrate and magnesium chloride showed no significant effects on the dough mixing properties. Most of chemicals were detrimental on the bread volume except MgSO_(4) and CaCl_(2). Breads with MgSO_(4) and CaCl_(2) retained the equal or slightly higher volume compared to control bread. Crumb and crust colors of breads with addition of chemicals were changed to lighter than that of control bread. L values both of crumb and crust increased with addition of chemicals except Ca-citrate. To inactivate the endogenous enzymes of flour, flour was roasted under electric oven, exposed to UV and microwave. Those heat treatments of flour increased dough stability and produced no dough breakdown after optimum mixing time. However, bread volume of heat-treated flour decreased.

Influence of thermally induced, dehydroxylated nanoclay on polymer nanocomposites

Priyanka Pandey,Sanjay Kumar Nayak,Smita Mohanty 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.8

This work reports a novel approach towards a chemical-free treatment of nanoclay through extensive thermalexposure. Dehydroxylation at high temperature was utilized to enhance the influence of nanoclay on the propertiesof polymer. The effect of this treatment of nanoclay, on the polymer properties, with reference to Polypropylene (PP)has been investigated. The FTIR spectra revealed the successful removal of water from the intergallery spacing of thenanoclay. The maintained structural configuration of the clay was confirmed using WAXD pattern. The uniform dispersionand exfoliation of thermally treated clay layers inside the polymer matrix was confirmed through enhancedmechanical properties. Improved crystallization properties, thermal stability and flame retardant characteristic werealso noticed in the nanocomposites reinforced with thermally dehydroxylated clay. This study revealed that the dehydroxylationapproach of modification of nanoclay may provide much enhanced properties of polymer, without involvementof any chemical for modification.

Microstructural and ferroelectric properties of rare earth (Ce, Pr, and Tb)-doped Na_0.5Bi_4.5Ti₃O₁₅ thin films

Raghavan, Chinnambedu Murugesan,Kim, Jin Won,Song, Tae Kwon,Kim, Sang Su Elsevier 2015 APPLIED SURFACE SCIENCE - Vol.355 No.-

<P><B>Abstract</B></P> <P>Pure Na<SUB>0.5</SUB>Bi<SUB>4.5</SUB>Ti<SUB>4</SUB>O<SUB>15</SUB> and rare earth-doped Na<SUB>0.5</SUB>Bi<SUB>4</SUB> <I>RE</I> <SUB>0.5</SUB>Ti<SUB>4</SUB>O<SUB>15</SUB> (<I>RE</I> =Ce, Pr, and Tb) thin films were prepared on Pt(111)/Ti/SiO<SUB>2</SUB>/Si(100) substrates by using a chemical solution deposition method. X-ray diffraction and Raman scattering spectroscopy studies revealed that the thin films are crystallized in a single-phase Aurivillius structure with no additional phases. The rare earth-doped Na<SUB>0.5</SUB>Bi<SUB>4</SUB> <I>RE</I> <SUB>0.5</SUB>Ti<SUB>4</SUB>O<SUB>15</SUB> thin films exhibited improved electrical and ferroelectric properties. Among the studied rare earth metal ions, the Tb<SUP>3+</SUP> ion leads to a remarkable improvement in the ferroelectric properties. The use of the Tb<SUP>3+</SUP> ion for doping resulted in a well-saturated ferroelectric hysteresis loop with a large remnant polarization (2<I>P</I> <SUB> <I>r</I> </SUB>) of 40μC/cm<SUP>2</SUP> and a low coercive electric field (2<I>E</I> <SUB> <I>c</I> </SUB>) of 176kV/cm, measured at an applied electric field of 475kV in the Na<SUB>0.5</SUB>Bi<SUB>4</SUB>Tb<SUB>0.5</SUB>Ti<SUB>4</SUB>O<SUB>15</SUB> thin film. Furthermore, the leakage current density of the Na<SUB>0.5</SUB>Bi<SUB>4</SUB>Tb<SUB>0.5</SUB>Ti<SUB>4</SUB>O<SUB>15</SUB> thin film was one order of magnitude lower than that of the Na<SUB>0.5</SUB>Bi<SUB>4.5</SUB>Ti<SUB>4</SUB>O<SUB>15</SUB> thin film.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effects of rare earth (Ce, Pr and Tb) doping on Na<SUB>0.5</SUB>Bi<SUB>4.5</SUB>Ti<SUB>4</SUB>O<SUB>15</SUB> thin films. </LI> <LI> Microstructural, electrical and ferroelectric properties of the thin films were investigated. </LI> <LI> Tb-doped Na<SUB>0.5</SUB>Bi<SUB>4.5</SUB>Ti<SUB>4</SUB>O<SUB>15</SUB> thin film showed rationally improved electrical and ferroelectric properties. </LI> </UL> </P>