• Title/Summary/Keyword: Solid solution treatment

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The Effect of Structure and Acidity of Fluorinated HZSM-5 on Ethylene Aromatization (불소화 HZSM-5의 구조 및 산도가 에틸렌 방향족화에 미치는 영향)

  • Kyeong Nan, Kim;Seok Chang, Kang;Geunjae, Kwak
    • Applied Chemistry for Engineering
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    • v.34 no.1
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    • pp.15-22
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    • 2023
  • Recent studies have actively investigated ways to improve the economic feasibility and efficiency of the Fischer-Tropsch process by increasing the yields of the monocyclic aromatic compounds (BTEX). In this study, ethylene was selected as a model of F-T-derived hydrocarbons, and the ethylene-to-aromatics (ETA) reaction was investigated according to changes in acid characteristics, mesopores, and crystallinity of HZSM-5 (HZ5). Fluorinated HZ5 was prepared by calcination followed by impregnation of an aqueous NH4F solution having different molar concentrations in HZ5, and the structural and chemical properties of F/HZ5 were investigated through Brunauer-Emmett-Teller (BET), solid-state nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), NH3-temperature-programmed desorption (TPD), and pyridine-IR spectroscopy. The ETA reactions were performed at 673 K under 0.1 MPa, and fluorinating HZ5 by an aqueous NH4F solution of 0.17 M improved ethylene conversion, BTEX selectivity, and catalytic stability due to acidity, mesopore fraction, and crystallinity.

Selection of Binder and Solid Materials for Pelleting Welsh Onion(Allium fistulosum L.) Seeds (파 펠렛종자 생산을 위한 접착제 및 피복재료 선발)

  • 강점순
    • Journal of Life Science
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    • v.12 no.6
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    • pp.721-730
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    • 2002
  • This study was carried out to select new pelleting binder and material for Welsh onion seeds. The optimum treatments of the various plant growth regulators to improve seed germination of the Welsh onion was also estimated. There were no significant effects of growth regulators on the germination percentage, but germination was faster according to the number of days to 50% of the final germination ($T_{50}$) and the mean number of days to germination (MDG) than those of the control. Germinability was increased when the seeds were soaked in gibberellic acid ($GA_3$) solution for 24hrs, even though there was no synergy effect on the germinability when $GA_3$ was mixed with 6-benzylaminopurine (BAP). The optimum treatment for improving germination of Welsh onion was observed when the tested seeds was soaked in 500 $\mu$M of $GA_3$ at $20^{\circ}C$ for 24hrs. Also, when the seeds soaked in the aforementioned treatment, the rate of germination was increased at lower temperature than at $20^{\circ}C$, the optimal temperature. The percentage and the speed of seed germination depended on the kinds of pelleting binder and their concentration. It showed that the higher the concentration of the binder for seeds pelleting, the lower the percentage of seed germination. Among the pelleting binder, polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) were the best binders for seed pelleting, because seed germination using those binder did not affect on the concentration of binder. On the other hand, Carboxymethy cellulose (CMC) and methyl cellulose (MC) severely inhibited the seed germination The germinability was also different arcording to the pelleting materials. Among the different 58 pelleting materials, kaoline alone, the mixture of bentonite and kaoline, the mixture of bentonite, calcium carbonate and diatomaceous earth #300 were found as the best pelleting materials for welsh onion seeds.

Effect of Priming and Seed Pellet Technique for Improved Germination and Growth in Fraxinus rhynchophylla and Alnus sibirica (프라이밍 및 종자펠렛 제조를 통한 물푸레나무와 물오리나무의 발아율 향상 및 생장증대 효과)

  • Park, Hae Il;Shim, Hoon Seob;Choi, Li Na;Jo, Hyeon Gil;Han, Seung Ho;Lee, Jae Geun;Yu, Chang Yeon;Lim, Jung Dae
    • Korean Journal of Medicinal Crop Science
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    • v.21 no.1
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    • pp.7-19
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    • 2013
  • This study was carried out to select new pelleting binder and material for seeds from Fraxinus rhynchophylla Hance and Alnus sibirica Fisch. ex Turcz. The optimum treatments of the various concentrations and species of priming agents to improve seed germination of both woody medicinal plants were also estimated. Germinability was increased when the seeds of Fraxinus rhynchophylla Hance was soaked in -1.0 MPa of PEG6000 solution at $15^{\circ}C$ for 4 days significantly, the optimum treatment for improving germination of Alnus sibirica Fisch. ex Turcz was observed when the tested seeds was soaked in 100 mM of KCl at $15^{\circ}C$ for 4 days. The influence of physical and chemical properties of pelleting solid materials, the mixture of gypsum, diatomaceous earth, dalma ceramic and vermicuolite (6:1:1:1 ratio) were found as the best pelleting materials for Fraxinus rhynchophylla Hance and Alnus sibirica Fisch. ex Turcz. seeds. To satisfy the requirements of absorption and compatibility for multi-layer seed pelleting, SGPA (Starch-grafted cross-linked polyacrylates) hydrogel was prepared using starch, acrylonitrile, ceric ammonium nitrate, nitric acid, methyl alcohol and potassium hydroxide. The resulting SGPA hydrogel showed high water absorption but not plant compatibility. It suggested that seed pelleting using pelleting materials and SGPA hydrogel (multi-layer coating) after priming agent treatment is to increase germinability and seedling growth and it can reduced irrigation labours and can also save seed.

Application of Continuous Stirred Tank Reactor Model for Water Quality Control and Management in Wetland Treatment (습지의 수질관리를 위한 연속교반탱크반응기 모델의 적용)

  • Kim, Kyung-Sub;Ahn, Tae-Jin;Kim, Min-Su
    • Journal of Korea Water Resources Association
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    • v.41 no.3
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    • pp.243-249
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    • 2008
  • Continuous stirred tank reactor(CSTR) model which can be applied to control and management of the surface flow wetland is developed to simulate the water quality in this research. The model solution is obtained from the optimization model using the least-squares and 4th-order Runge-Kutta methods. The model is applied to simulate BOD and TSS in the wetland database of U.S. EPA, in which the hydraulic and water quality data are enough and the number of pond is just one for simple analysis of running results. The model is tested in two different cases, one constant volume case and another constant volume and flow rate case considering only reaction term, mass flux term and both reaction and mass flux terms respectively. It is found that the model simulates the real water quality very well with both reaction and mass flux terms rather than only reaction term and the settling velocity of TSS becomes $0.3{\sim}0.4\;m/d$. The model can be applied in wetlands treatment efficiently.

Application of Porous Nanofibers Comprising Hollow α-Fe2O3 Nanospheres Prepared by Applying Both PS Template and Kirkendall Diffusion Effect for Anode Materials in Lithium-ion Batteries (커켄달 효과와 주형법을 통해 합성한 α-Fe2O3 중공입자로 구성된 다공성1차원 구조체의 리튬 이차전지 음극활물질 적용)

  • Lee, Young Kwang;Jeong, Sun Young;Cho, Jung Sang
    • Korean Chemical Engineering Research
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    • v.56 no.6
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    • pp.819-825
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    • 2018
  • Porous nanofibers comprising hollow ${\alpha}-Fe_2O_3$ nanospheres were prepared by applying both template method and Kirkendall diffusion effect to electrospinning process. During heat-treatment processes, the solid Fe nano-metals formed by initial heat-treatment in the carbon matrix were converted into the hollow structured ${\alpha}-Fe_2O_3$ nanospheres. In particular, PS nanobeads added in the spinning solution were decomposed and formed numerous channels in the composite, which served as a good pathway for Kirkendall diffusion gas. The resulting porous nanofibers comprising hollow ${\alpha}-Fe_2O_3$ nanospheres were applied as an anode material for lithium-ion batteries. The discharge capacities of the nanofibers for the 30th cycle at a high current density of $1.0A\;g^{-1}$ was $776mA\;h\;g^{-1}$. The good lithium ion storage property was attributed to the synergetic effects of the hollow ${\alpha}-Fe_2O_3$ nanospheres and the interstitial nanovoids between the nanospheres. The synthetic method proposed in this study could be applied to the preparation of porous nanofibers comprising hollow nanospheres with various composition for various applications, including energy storage.

Effects of Boliing, Steaming, and Chemical Treatment on Solid Wood Bending of Quercus acutissima Carr. and Pinus densiflora S. et. Z. (자비(煮沸), 증자(蒸煮) 및 약제처리(藥劑處理)가 상수리나무와 소나무의 휨가공성(加工性)에 미치는 영향(影響))

  • So, Won-Tek
    • Journal of the Korean Wood Science and Technology
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    • v.13 no.1
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    • pp.19-62
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    • 1985
  • This study was performed to investigate: (i) the bending processing properties of silk worm oak (Quercus acutissima Carr.) and Korean red pine (Pinus densiflora S. et Z.) by boiling and steaming treatments; (ii) the effects of interrelated factors - sapwood and heartwood, annual ring placement, softening temperature and time, moisture content. and wood defects on bending processing properties; (iii) the changing rates of bending radii after release from a tension strap, and (iv) the improving methods of bending process by treatment with chemicals. The size of specimens tested was $15{\times}15{\times}350mm$ for boiling and steaming treatments and $5{\times}10{\times}200mm$ for treatments with chemicals. The specimens were green for boiling treatments and dried to 15 percent for steaming treatments. The specimens for treatments with chemicals were soaked in saturated urea solution, 35 percent formaldehyde solution, 25 percent polyethylene glycol -400 solution, and 25 percent ammonium hydroxide solution for 5 days and immediately followed the bending process, respectively. The results obtained were as follows: 1. The internal temperature of silk worm oak and Korean red pine by boiling and steaming time was raised slowly to $30^{\circ}C$ but rapidly from $30^{\circ}C$ to $80-90^{\circ}C$ and then slowly from $80-90^{\circ}C$ to $100^{\circ}C$. 2. The softening time required to the final temperature was directly proportional to the thickness of specimen. The time required from $25^{\circ}C$ to $100^{\circ}C$ for 15mm-squared specimen was 9.6-11.2 minutes in silk worm oak and 7.6-8.1 minutes in Korean red pine. 3. The moisture content (M.C.) of specimen by steaming time was increased rapidly first 4 minutes in the both species, and moderately from 4 to 20 minutes and then slowly and constantly in silk worm oak, and moderately from 4 to 15 minutes and then slowly and constantly in Korean red pine. The M.C. of 15mm-squared specimen in 50 minutes of steaming was increased to 18.0 percent in the oak and 22.4 percent in the pine from the initial conditioned M.C. of 15 percent The rate of moisture adsorption measured was therefore faster in the pine than in the oak. 4. The mechanical properties of the both species were decreased significantly with the increase of boiling rime. The decrement by the boiling treatment for 60 minutes was measured to 36.6-45.0 percent in compressive strength, 12.5-17.5 percent in tensile strength, 31.6-40.9 percent in modulus of rupture, and 23.3-34.6 percent in modulus of elasticity. 5. The minimum bending radius (M.B.R.) of sapwood and heartwood was 60-80 mm and 90 mm in silk worm oak, and 260 - 300 mm and 280 - 300 mm in Korean red pine, respectively. Therefore, the both species showed better bending processing properties in sapwood than in heartwood. 6. The M.B.R. of edge-grained and flat-grained specimen in suk worm oak was 60-80 mm, but the M.B.R. in Korean red pine was 240-280 mm and 260-360 mm, respectively. Comparing the M.B.R. of edge-grained with flat-grained specimen, in the pine the edge-grained showed better bending processing property than the flat-grained. 7. The bending processing properties of the both species were improved by the rising of softening temperature from $40^{\circ}C$ to $100^{\circ}C$. The minimum softening temperature for bending was $90^{\circ}C$ in silk worm oak and $80^{\circ}C$ in Korean red pine, and the dependency of softening temperature for bending was therefore higher in the oak than in the pine. 8. The bending processing properties of the both species were improved by the increase of softening time as well as temperature, but even after the internal temperature of specimen reaching to the final temperature, somewhat prolonged softening was required to obtain the best plastic conditions. The minimum softening time for bending of 15 mm-squared silk worm oak and Korean red pine specimen was 15 and 10 minutes in the boiling treatment, and 30 and 20 minutes in the steaming treatment, respectively. 9. The optimum M.C. for bending of silk worm oak was 20 percent, and the M.C. above fiber saturation point rather degraded the bending processing property, whereas the optimum M.C. of Korean red pine needed to be above 30 percent. 10. The bending works in the optimum conditions obtained as seen in Table 24 showed that the M.B.R. of silk worm oak and Korean red pine was 80 mm and 240 mm in the boiling treatment, and 50 mm and 280 mm in the steaming treatment, respectively. Therefore, the bending processing property of the oak was better in the steaming than in the boiling treatment, but that of the pine better in the boiling than in the steaming treatment. 11. In the bending without a tension strap, the radio r/t of the minimum bending radius t to the thickness t of silk worm oak and Korean red pine specimen amounted to 16.0 and 21.3 in the boiling treatment, and 17.3 and 24.0 in the steaming treatment, respectively. But in the bending with a tension strap, the r/t of the oak and the pine specimen decreased to 5.3 and 16.0 in t he boiling treatment, and 3.3 and 18.7 in the steaming treatment, respectively. Therefore, the bending processing properties of the both species were significantly improved by the strap. 12. The effect of pin knot on the degradation of bending processing property was very severe in silk worm oak by side, e.g. 90 percent of the oak specimens with pin knot on the concave side were ruptured when bent to a 100 mm radius but only 10 percent of the other specimens with pin knot on the convex side were ruptured. 13. The changing rate in the bending radius of specimen bent to a 300 mm radius after 30 days of exposure to room temperature conditions was measured to 4.0-10.3 percent in the boiling treatment and 13,0-15.0 percent in the steaming treatment. Therefore, the degree of spring back after release was higher in the steaming than in the boiling treatment. And the changing rate of moisture-proofing treated specimen by expoxy resin coating was only -1.0.0 percent. 14. Formaldehyde, 35 percent solution, and 25 percent polyethylene glycol-400 solution found no effect on the plasticization of the both species, but saturated urea solution and 25 percent ammonium hydroxide solution found significant effect in comparison to non-treated specimen. But the effect of the treatment with chemicals alone was inferior to that of the steaming treatment, and the steaming treatment after the treatment with chemicals improved 10-24 percent over the bending processing property of steam-bent specimen. 15. Three plasticity coefficients - load-strain coefficient, strain coefficient, and energy coefficient - were evaluated to be appropriate for the index of bending processing property because the coefficients had highly significant correlation with the bending radius. The fitness of the coefficients as the index was good at load-strain coefficient, energy coefficient, and strain coefficient, in order.

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Effects of Thawing Conditions in Sample Treatment on the Chemical Properties of East Siberian Ice Wedges (동시베리아 얼음쐐기 시료의 해동방법이 시료의 화학적 특성분석에 미치는 영향)

  • Subon Ko;Jinho Ahn;Alexandre Fedorov;Giehyeon Lee
    • Economic and Environmental Geology
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    • v.55 no.6
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    • pp.727-736
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    • 2022
  • Ice wedges are subsurface ice mass structures that formed mainly by freezing precipitation with airborne dust and surrounding soil particles flowed through the active layer into the cracks growing by repeating thermal contractions in the deeper permafrost layer over time. These ice masses characteristically contain high concentrations of solutes and solids. Because of their unique properties and distribution, the possibility of harnessing ice wedges as an alternative archive for reconstructing paleoclimate and paleoenvironment has been recently suggested despite limited studies. It is imperative to preserve the physicochemical properties of the ice wedge (e.g., solute concentration, mineral particles) without any potential alteration to use it as a proxy for reconstructing the paleo-information. Thawing the ice wedge samples is prerequisite for the assessment of their physicochemical properties, during which the paleo-information could be unintentionally altered by any methodological artifact. This study examined the effect of thawing conditions and procedures on the physicochemical properties of solutes and solid particles in ice wedge samples collected from Cyuie, East Siberia. Four different thawing conditions with varying temperatures (4 and 23℃) and oxygen exposures (oxic and anoxic) for the ice wedge sample treatment were examined. Ice wedge samples thawed at 4℃ under anoxic conditions, wherein biological activity and oxidation were kept to a minimum, were set as the standard thawing conditions to which the effects of temperature and oxygen were compared. The results indicate that temperature and oxygen exposure have negligible effects on the physicochemical characteristics of the solid particles. However, the chemical features of the solution (e.g., pH, electric conductivity, alkalinity, and concentration of major cations and trace elements) at 4℃ under oxic conditions were considerably altered, compared to those measured under the standard thawing conditions. This study shows that the thawing condition of ice wedge samples can affect their chemical features and thereby the geochemical information therein for the reconstruction of the paleoclimate and/or paleoenvironment.

Preparation of Nickel Hexacyanoferrate Ion Exchanger for Electrochemical Separation of Cations (양이온의 전기화학적 분리를 위한 페리시안니켈 이온교환체의 제조에 관한 연구)

  • Lee, Ji Hyun;Hwang, Young Gi
    • Applied Chemistry for Engineering
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    • v.21 no.1
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    • pp.52-57
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    • 2010
  • Although chemical sedimentation and ion exchange are usually applied to the treatment of heavy metal ions and radioactive cations, they have some serious disadvantages like a great consumption of chemicals, the disposal of valuable metals, and the secondary pollution of soil by the solid-waste. The advanced countries recently have studied the electrochemical ion exchange, combined electrochemical reduction and ion exchange, for the development of the alternative technique. This study has been performed to investigate the optimum condition for the preparation of the nickel hexacyanoferrate (NiHCNFe) which is an electrochemical ion exchanger. NiHCNFe film was deposited on the surface of nickel plate by chemical method or electrochemical method. The morphology and composition of NiHCNFe were observed by SEM and EDS, respectively. The peak current density of NiHCNFe was measured from the cyclic voltammograms of the continuous oxidation-reduction reaction in a parallel plane ion exchange electrode reactor. It was found that the chemical preparation method was better than the electrochemical method. The concentrated NiHCNFe was apparently deposited on nickel plate when dipping in the preparing solution for 118 h, especially. It also had a best durable performance as an ion exchange electrode.

Effect of Gamma Ray Irradiation on the Availability of Applied $^{65}Zn$ to Applied at Organic Matter Added Soils under Laboratory Conditions

  • Kim, Tai-Soon;Han, Kang-Wan
    • Nuclear Engineering and Technology
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    • v.11 no.2
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    • pp.105-110
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    • 1979
  • In order to evaluate the effect of gamma ray irradiation to the soils added with several organic matters on release sad fixation of $^{65}Zn$, a soil incubation test was carried out by use of an acidic and a calcareous soil. The results obtained were summarized as follows : DTPA extractable $^{65}Zn$ decreased gradually with elapsed time of incubation owing to fixation of $^{65}$Zn by the soils but after four weeks DTPA extractable $^{65}Zn$ was reached an equilibrium state. The most parts of $^{65}Zn$ activity in the equilibrium state was found in the solid phase. The extent of zinc fixation in acidic Keumgok and calcareous Jecheon soils represented as activity basis was 89 and 93.7 per cent of applied $^{65}Zn$ respectively. Increased tendency of DTPA extractable zinc was shown by irradiating gamma ray to both soils because of $^{65}Zn$ fixation could be decreased by irradiation. The extractability of fixed $^{65}Zn$ by DTPA solution was 38.9 per cent in acidic Keumgok soil and only 9.5 per cent in calcareous Jecheon soil. Release of fixed $^{65}Zn$ by irradiation of gamma ray is closely related to pH of both soils. Much more $^{65}Zn$ could be released under low pH condition. Effect of gamma ray irradiation to organic matter sources on release of $^{65}Zn$ could not be differentiated. But in the case of nonirradiated soils, however, glucose treated soils couldrelease much more the extractable zinc as compared to those of the straw or cellulose treatment.

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Development of Adsorbent for Removing Toxic Organic Compounds(II) - Characterization of Adsolubilization of Organic Compounds by the Organo-anthracite - (유독성 유기화합물 제거를 위한 흡착제 개발(II) - Organo-anthracite에 의한 유기화합물의 흡착용해 특성 -)

  • Jang, Hyun-Suk;Park, Sang-Won
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.3
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    • pp.557-564
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    • 2000
  • This study is aimed to develop the adsorbent which can effectively remove toxic hydrophobic organic compounds from the aqueous phase. The emphasis was made to elucidate the adsolubilization behavior of sparingly soluble organic compounds (SSOCs) into the cetyltrimetylammonium bromide(CTAB) layer formed on anthracite by the partition coefficient. The amount of SSOCs removed from aqueous solution was increased with increase of the amount of CTAB coated on the surface and wich increase of SSOCs's hydrophobicity. With the surface-modified solid shown in above. chloroform and benzene at the initial concentration of $6{\times}10^{-4}M$ were removed over 95%. Experimentally determined partition coefficient($K_d$) values between organo-anthracite and organics were 4~25 times higher than theoretical $K_d$ values of same organics Organo-anthracite formed by the addition of the CTAB can effectively immobilize organic contaminants dissolved in landfill leachate and can also be applicable to wastewater treatment containing toxic hydrophobic organic compounds such as chloroform and benzene.

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