• Title, Summary, Keyword: absorption

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Analysis of Factors Rerated to Absorption Ability of Foliage Plants Exposed to $O_3$ (관엽식물의 오존($O_3$)흡수능에 관여하는 요인 분석)

  • 박소홍;배공영
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.6
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    • pp.537-544
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    • 1998
  • We selected Spathiyhyllum patinii and Pachira aqkatica, since the former has high O3 absorption while the latter low absorption, and analyzed physiological factors such as diffusive coefficient, transpiration rate, photosynthetic rate, and CO2 absorption rate, which affected O3 absorption capacity There was significant relationship between gas absorption capacity and the other factors; photosynthetic rate, diffusive resistance, stomatal resistance and CO2 absorption rate. Therefore model formula for estimation of O3 absorption rate in plant was formulated by making use of these factors. There was difference for the estimation of O3 absorption rate according to plant species. In case of Spathiphyllum patinii, photosynthetic rate is an optimal factor for estimation of O3 absorption capacity. On the other hand, stomatal resistance and diffusive resistance are optimal factors of Pachira aquatica among various physiological ones. And we knew that CO2 absorption rate is a potential factor to evaluate gas absorption capacity regardless of plant species. But considering efficiency and practicality, diffusive resistance was the most effective factor for the estimation of O3 gas absorption.

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Potential of different additives to improve performance of potassium carbonate for CO2 absorption

  • Ramezani, Rouzbeh;Mazinani, Saeed;Di Felice, Renzo
    • Korean Journal of Chemical Engineering
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    • v.35 no.10
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    • pp.2065-2077
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    • 2018
  • The performance of potassium carbonate ($K_2CO_3$) solution promoted by three amines, potassium alaninate (K-Ala), potassium serinate (K-Ser) and aminoethylethanolamine (AEEA), in terms of heat of absorption, absorption capacity and rate was studied experimentally. The experiments were performed using a batch reactor, and the results were compared to pure monoethanolamine (MEA) and $K_2CO_3$ solutions. The heat of absorption of $K_2CO_3$+additive solution was calculated using the Gibbs-Helmholtz equation. In addition, a correlation for prediction of $CO_2$ loading was presented. The results indicated that absorption heat, absorption rate and loading capacity of $CO_2$ increase as the concentration of additive increases. The blend solutions have higher $CO_2$ loading capacity and absorption rate when compared to pure $K_2CO_3$. The heat of $CO_2$ absorption for $K_2CO_3$+additive solutions was found to be lower than that of the pure MEA. Among the additives, AEEA showed the highest $CO_2$ absorption capacity and absorption rate with $K_2CO_3$. In conclusion, the $K_2CO_3$+AEEA solution with high absorption performance can be a potential solvent to replace the existing amines for $CO_2$ absorption.

Heavy Metal Absorption Properties of Sulfonated Polyethylene Terephthalate (Sulfonated Polyethylene Terephthalate의 중금속 흡착능)

  • Kang, Young-Goo;Kim, Dong-Hyun
    • Journal of the Korean Society of Safety
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    • v.18 no.4
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    • pp.92-97
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    • 2003
  • The purpose of this study is heavy metal absorption of recycled PET(poly ethylene terephatalate) NWF(non woven faric). The results of test are summarized as follows; Heavy metal abworption rates in Ni ions were higher then Zn and Cu ions, whereas heavy metal absorption rates by sulfonation times were not different. The heavy metal absorption times have a higher tendency from 60 min to 120 min. There were significant negative correlations among the amount used CSA(Chloro Sulfuric Acid) and the amount of absorption Zn(r = -0.33784, p < 0.05), Cu(r = -0.61177, p < 0.01) ions, whereas correlations between heavy metal absorption rates and sulfonation times were not significant. There were significant positive correlations among the amount of absorption Zn ions and the amount of absorption Ni(r = 96475, p < 0.014), Cu(r = 0.51614, p < 0.01) ions, likewise the positive correlations between the amount of absorption N ions and the amount of absorption Cu(r = 0.54766) ions were significant(p < 0.01).

Sound Absorption Characteristics of Permeable Membrane (통기성을 갖는 막재료의 흡음특성)

  • Jeong, Jeong-Ho;Kim, Jung-Joong;Kim, Ku-Je
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.270-275
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    • 2009
  • Sound absorption characteristics of membrane system which are used in stadiums and arenas were investigated. Theoretical studies on acoustic properties of single and double leaf permeable membrane conducted. Also, experimental studies on sound absorption characteristics of combined membrane system that is composed of outer and inner membrane material were conducted. In this study, sound absorption characteristics of each membrane were investigated by experiments in reverberation chamber. 4 types of permeable membranes and a non-permeable membrane were used for experiments. Air space behind membrane material and tension on the membrane was varied. Sound absorption performance of permeable membrane materials was confirmed. As increasing air space behind the membrane material, sound absorption coefficient was increased. In a resonance absorption frequency band sound absorption coefficient varied more dramatically. Sound absorption characteristics were flat in mid and high frequency range and sound absorption coefficient was from 0,3 to 0,5. Also sound absorption coefficient was increased by the increment of surface density and air permeability of membrane. However, over the certain value of air permeability, sound absorption coefficient was decreased. These results can be used as design factors and method for the room acoustic design of dome-stadiums and large free-form buildings.

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A Study on the Sound Absorption Properties of Sound Absorption Block using by Artificial Light Weight Aggregate (인공경량골재를 이용한 철도 흡음블록의 흡음특성에 관한 연구)

  • Kang, Duck-Man;Seo, Jae-Won;Lee, In-Yong;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • pp.830-839
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    • 2008
  • This study is designed to manufacture the upgraded sound absorption concrete by using foamed concrete by using artificial light weight aggregate which raises the continuous void ratio to increase the sound absorption ratio and improve the strength. In manufacturing the sound absorption block, the pre-foaming form is applied to generate continuous voids, controlling the density by the addition of bubbles. It is general that the more porosity creates, the weaker strength becomes. Each of specimens are used for this experiment and measured their absorption ratio to examine the absorption property depending on frequency. As a results of experiment, it is evaluated that the absorption capacity of the sound absorption block has relation to compression strength and surface shape.

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A Study on the Characteristic of Sound Absorption of Flyash Blocks (Flyash를 이용한 블록의 흡음특성에 관한 연구)

  • 변홍식;이태관
    • Journal of Environmental Science International
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    • v.11 no.3
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    • pp.235-240
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    • 2002
  • The blocks using flyash were prepared in this study. The characteristic of sound absorption of flyash block was investigated. It was revealed that the chemical additives and flyash played an important role to determine the characteristic of sound absorption. Chemical additive affects the capability of sound absorption while flyash affects the characteristic of sound absorption, i.e. high value of the sound absorption coefficient at the specific frequencies(1KHz and 2KHz). The flyash block showed higher sound absorption coefficient than that of the commercial concrete block having carpet on the surface. It was also shown that the sound absorption coefficient increases with increase of the content of flyash in the block. However, it was found that the 70wt% of flyash in the flyash block was the optimum content to obtain the highest sound absorption coefficient.

An Experimental Study on the Effect of Air Space on the Absorption Property of Composite Absorption System (배후공기층이 복합흡음구조의 흡음특성에 미치는 영향에 관한 실험적 연구)

  • Oh, Yang-Ki
    • KIEAE Journal
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    • v.1 no.2
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    • pp.47-54
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    • 2001
  • Single sound absorbers such as porous materials, panels, and Helmholts resonators have limited performance with some extents of frequency region. For example, porous materials do not attenuate low frequency sounds, while panels do not absorb high frequency sounds. Composite absorption structure with coverings, porous materials, and air gaps are an alternative for wide band sound absorption. Slits, panels, perforated panels are those materials for coverings, glass wool, mineral wool, polyester, and polyurethane are frequently used porous materials. Air gap between the porous material and background surface is one of major factors which governs the absorption characteristics of composite absorption structures, especially in the low frequency area. Calculations and measurements show that the absorption coefficients of composite absorption structure, in mid and low frequency bands, are getting higher with increased air gaps. Perforated panels rather than slits and panels are good coverings with higher number as far as absorption coefficient is concerned. Perforated panels with porous materials and 37 cm of air gaps in background have high absorption coefficients for all frequency bands, above 0.7 to 1.0. All measurements are performed in reverberation chamber, Mokpo National University, according to ISO 354 and ISO 3382.

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Absorption Spectroscopy of Biological Specimens Near X-ray Absorption Edges of Constituent Elements

  • Ito, Atsushi;Shinohara, Kunio
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.460-462
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    • 2002
  • Absorption spectra of biological specimens in the soft X-ray region have been presented with special reference to the XANES (X-ray absorption Near Edge Structure) of constituent elements. Absorption spectrum in this wavelength region is characterized by the absorption edges from which elemental content could be derived. In addition, XANES has a characteristic profile for chemical environment around the element such as chemical bond. Using the specific absorption peak we can assign not only the chemical bond but also molecules having such a chemical bond. In the present paper, absorption spectrum of DNA was measured in the wavelength range from 1.5nm to 5nm. Spectrum of Chinese Hamster Ovary (CHO) cells was compared with the DNA spectrum. XANES were distinct at the K absorption edges of major elements, C, N and O. In the spectrum of the cells prominent peaks at the L absorption edge of minor element Ca were also detectable. XANES profiles in small local areas in a cell could also be measured in combination with X-ray microscopy. These give information about local chemical environment in a cell. XANES at the phosphorus K absorption edge in a human HeLa cell was successfully obtained corresponding to a sharp and intensive XANES peak of DNA.

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Effects of the Changes in Handsheet Structure on the Water Absorption and Moisture Absorption (수초지 구조변화에 따른 흡수·흡습 특성 변화 연구)

  • Sung, Yong Joo;Kim, Dong Sung;Lee, Ji Young
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.48 no.3
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    • pp.30-36
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    • 2016
  • This study was conducted to investigate the influence of the changes in handsheet structure by beating, wet pressing and the addition of wood flour spacer on the water absorption and the moisture absorption properties. The higher beating treatment of BKP resulted in the denser structure of handsheet samples, which leaded to the lower water and moisture absorption. The wet pressing showed the similar effects by reducing the bulk of handsheets. In case of the handsheet samples with similar bulk structure made of different beaten pulps, the severer beating treatment increased the water absorption and the moisture absorption. The addition of the wood flour spacer resulted in the higher bulk following the higher water and moisture adsorption. Since the water and the moisture absorption properties of paper products could greatly affect on not only the product quality but also the process runnability, the control of the water response of paper product has been considered as very important technology. The results of this study might be useful for control of water and moisture absorption properties of paper products.

Capillary Water Absorption Properties of Steel Fiber Reinforced Coal Gangue Concrete under Freeze-Thaw Cycles

  • Qiu, Jisheng;Zheng, Juanjuan;Guan, Xiao;Pan, Du;Zhang, Chenghua
    • Korean Journal of Materials Research
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    • v.27 no.8
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    • pp.451-458
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    • 2017
  • The service life of coal gangue concrete(CGC) strongly depends on the capillary water absorption, this water absorption is susceptible to freeze-thaw cycles. In this paper, the cumulative water absorption and sorptivity were obtained to study the effects of 0, 0.5, 1.0, and 1.5 % steel fiber volume fraction added on the water absorption of CGC. Sorptivity and freeze-thaw tests were conducted, and the capillary water absorption was evaluated by the rate of water absorption(sorptivity). Three prediction models for the initial sorptivity of steel fiber reinforced coal gangue concrete(SFRCGC) under freeze-thaw cycles were established to evaluate the capillary water absorption of SFRCGC. Results showed that, without freeze-thaw cycles, the water absorption of CGC decreased when steel fiber at 1.0 % volume fraction was added, however, the water absorption increased with the addition of 0.5 or 1.5 % steel fibers. Once the SFRCGC specimens were exposed to freeze-thaw cycles, the water absorption of SFRCGC significantly increased, and 1.0 % steel fiber in volume fraction added to CGC caused the lowest water absorption, except for the case of the sample without steel fibers added. The CGC with steel fiber at 1.0 % volume fraction performed better. The SFRCGC has a strong response to freeze-thaw cycles. Results also showed that the linear function prediction model is practical in the field of engineering because of its simple form and a relatively high precision. Although the polynomial prediction model presents the highest computation precision among the three models, the complicated form and too many coefficients make it impractical for engineering applications.