• Title/Summary/Keyword: Small molecules

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INTRINSIC NMR ISOTOPE SHIFTS OF CYCLOOCTANONE AT LOW TEMPERATURE (저온에서의 싸이클로옥타논에 대한 고유동위원소 효과)

  • Jung, Miewon
    • Analytical Science and Technology
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    • v.7 no.2
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    • pp.213-224
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    • 1994
  • Several isotopomers of cyclooctanone were prepared by selective deuterium substitution. Intrinsic isotope effects on $^{13}C$ NMR chemical shifts of these isotopomers were investigated systematically at low temperature. These istope effects were discussed in relation to the preferred boat-chair conformation of cyclooctanone. Deuterium isotope effects on NMR chemical shifts have been known for a long time. Especially in a conformationally mobile molecule, isotope perturbation could affect NMR signals through a combination of isotope effects on equilibria and intrinsic effects. The distinction between intrinsic and nonintrinsic effects is quite difficult at ambient temperature due to involvement of both equilibrium and intrinsic isotope effects. However if equilibria between possible conformers of cyclooctanone are slowed down enough on the NMR time scale by lowering temperature, it should be possible to measure intrinsic isotope shifts from the separated signals at low temperature. $^{13}C$ NMR has been successfully utilized in the study on molecular conformation in solution when one deals with stable conformers or molecules were rapid interconversion occurs at ambient temperature. The study of dynamic processes in general requires analysis of spectra at several temperature. Anet et al. did $^1H$ NMR study of cyclooctanone at low temperature to freeze out a stable conformation, but were not able initially to deduce which conformation was stable because of the complexity of alkyl region in the $^1H$ NMR spectrum. They also reported the $^1H$ and $^{13}C$ NMR spectra of the $C_9-C_{16}$ cycloalkanones with changing temperature from $-80^{\circ}C$ to $-170^{\circ}C$, but they did not report a variable temperature $^{13}C$ NMR study of cyclooctanone. For the analysis of the intrinsic isotope effect with relation to cylooctanone conformation, $^{13}C$ NMR spectra are obtained in the present work at low temperatures (up to $-150^{\circ}C$) in order to find the chemical shifts at the temperature at which the dynamic process can be "frozen-out" on the NMR time scale and cyclooctanone can be observed as a stable conformation. Both the ring inversion and pseudorotational processes must be "frozen-out" in order to see separate resonances for all eight carbons in cyclooctanone. In contrast to $^1H$ spectra, slowing down just the ring inversion process has no apparent effects on the $^{13}C$ spectra because exchange of environments within the pairs of methylene carbons can still occur by the pseudorotational process. Several isotopomers of cyclooctanone were prepared by selective deuterium substitution (fig. 1) : complete deuterium labeling at C-2 and C-8 positions gave cyclooctanone-2, 2, 8, $8-D_4$ : complete labeling at C-2 and C-7 positions afforded the 2, 2, 7, $7-D_4$ isotopomer : di-deuteration at C-3 gave the 3, $3-D_2$ isotopomer : mono-deuteration provided cyclooctanone-2-D, 4-D and 5-D isotopomers : and partial deuteration on the C-2 and C-8 position, with a chiral and difunctional case catalyst, gave the trans-2, $8-D_2$ isotopomer. These isotopomer were investigated systematically in relation with cyclooctanone conformation and intrinsic isotope effects on $^{13}C$ NMR chemical shifts at low temperature. The determination of the intrinsic effects could help in the analysis of the more complex effects at higher temperature. For quantitative analysis of intrinsic isotope effects, the $^{13}C$ NMR spectrum has been obtained for a mixture of the labeled and unlabeled compounds because the signal separations are very small.

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Film Dosimetry for Intensity Modulated Radiation Therapy : Dosimetric Evaluation (필름을 사용한 세기변조치료법에 대한 선량측정)

  • Ju Sang Gyu;Yeo Inhwan Jason;Huh Seung Jae;Choi Byung Ki;Park Young Hwan;Ahn Yong Chan;Kim Dae Yong;Kong Young Kun
    • Radiation Oncology Journal
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    • v.20 no.2
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    • pp.172-178
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    • 2002
  • Purpose : X-ray film over responds to low-energy photons in relative photon beam dosimetry because its sensor is based on silver bromide crystals, which are high-Z molecules. This over-response becomes a significant problem in clinical photon beam dosimetry particularly in regions outside the penumbra. In intensity modulated radiation therapy (IMRT), the radiation field is characterized by multiple small fields and their outside-penumbra regions. Therefore, in order to use film dosimetry for IMRT, the nature the source of the over-response in its radiation field need to be known. This study is aimed to verify and possibly improve film dosimetry for IMRT. Materials and Method : Modulated beams were constructed by a combination of five or seven different static radiation fields using 6 MeV X-rays. In order to verify film dosimetry, we used X-ray film and an ion chamber were used to measure the dose profiles at various depths in a phantom. In addition, in order to reduce the over-response, 0.01 inch thick lead filters were placed on both sides of the film. Results : The measured dose profiles showed a film over-response at the outside-penumbra and low dose regions. The error increased with depths and approached 15% at a maximum for the field size of $15{\times}15cm^2$ at 10 cm depth. The use of filters reduced the error to 3%, but caused an under-response of the dose in a perpendicular set-up. Conclusion : This study demonstrated that film dosimetry for IMRT involves sources of error due to its over-response to low-energy Photons. The use of filers can enhance the accuracy in film dosimetry for IMRT. In this regard, the use of optimal filter conditions is recommended.

Impact of Sulfur Dioxide Impurity on Process Design of $CO_2$ Offshore Geological Storage: Evaluation of Physical Property Models and Optimization of Binary Parameter (이산화황 불순물이 이산화탄소 해양 지중저장 공정설계에 미치는 영향 평가: 상태량 모델의 비교 분석 및 이성분 매개변수 최적화)

  • Huh, Cheol;Kang, Seong-Gil;Cho, Mang-Ik
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.13 no.3
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    • pp.187-197
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    • 2010
  • Carbon dioxide Capture and Storage(CCS) is regarded as one of the most promising options to response climate change. CCS is a three-stage process consisting of the capture of carbon dioxide($CO_2$), the transport of $CO_2$ to a storage location, and the long term isolation of $CO_2$ from the atmosphere for the purpose of carbon emission mitigation. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the $CO_2$ mixture captured from the power plants and steel making plants contains many impurities such as $N_2$, $O_2$, Ar, $H_2O$, $SO_2$, $H_2S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification, transport and injection processes. In order to design a reliable $CO_2$ marine geological storage system, it is necessary to analyze the impact of these impurities on the whole CCS process at initial design stage. The purpose of the present paper is to compare and analyse the relevant physical property models including BWRS, PR, PRBM, RKS and SRK equations of state, and NRTL-RK model which are crucial numerical process simulation tools. To evaluate the predictive accuracy of the equation of the state for $CO_2-SO_2$ mixture, we compared numerical calculation results with reference experimental data. In addition, optimum binary parameter to consider the interaction of $CO_2$ and $SO_2$ molecules was suggested based on the mean absolute percent error. In conclusion, we suggest the most reliable physical property model with optimized binary parameter in designing the $CO_2-SO_2$ mixture marine geological storage process.

Effect of Nitrogen Impurity on Process Design of $CO_2$ Marine Geological Storage: Evaluation of Equation of State and Optimization of Binary Parameter (질소 불순물이 이산화탄소 해양 지중저장 공정설계에 미치는 영향 평가: 상태방정식의 비교 분석 및 이성분 매개변수 최적화)

  • Huh, Cheol;Kang, Seong-Gil
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.12 no.3
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    • pp.217-226
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    • 2009
  • Marine geological storage of $CO_2$ is regarded as one of the most promising options to response climate change. Marine geological storage of $CO_2$ is to capture $CO_2$ from major point sources, to transport to the storage sites and to store $CO_2$ into the marine geological structure such as deep sea saline aquifer. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the captured $CO_2$ mixture contains many impurities such as $N_2$, $O_2$, Ar, $H_2O$, $SO_x$, $H_2S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification and transport processes. In order to design a reliable $CO_2$ marine geological storage system, it is necessary to perform numerical process simulation using thermodynamic equation of state. The purpose of the present paper is to compare and analyse the relevant equations of state including PR, PRBM, RKS and SRK equation of state for $CO_2-N_2$ mixture. To evaluate the predictive accuracy of the equation of the state, we compared numerical calculation results with reference experimental data. In addition, optimum binary parameter to consider the interaction of $CO_2$ and $N_2$ molecules was suggested based on the mean absolute percent error. In conclusion, we suggest the most reliable equation of state and relevant binary parameter in designing the $CO_2-N_2$ mixture marine geological storage process.

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The Origin of Meju Fungi - Fungal Diversity of Soybean, Rice Straw and Air for Meju Fermentation

  • Kim, Dae-Ho;Lee, Jong-kyu;Hong, Seung-Beom
    • 한국균학회소식:학술대회논문집
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    • 2014.10a
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    • pp.32-32
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    • 2014
  • Meju is a brick of dried fermented soybeans and is the core material for Jang such as Doenjang and Ganjang. Jang is produced by addition of salty water to Meju and is considered the essential sauces of authentic Korean cuisine. Meju is fermented by diverse microorganisms such as bacteria, fungi and yeasts. It is known that fungi play an important role in the Meju fermentation and they degrade macromolecules of the soybeans into small nutrient molecules. In previous study, 26 genera and 0 species were reported as Meju fungi. However, it is not comprehensively examined where the fungi present on the Meju are originated. In order to elucidate the origin of the fungi present on the Meju, the mycobiota of 500 samples soybean kernels, 296 rice straw pieces and air samples of Jang factories was determined in 0, 2 and 7 Jang factories respectively. Forty-one genera covering 86 species were isolated from the soybeans and 33 species were identical with the species from Meju. From sodium hypochlorite untreated soybeans, Eurotium herbariorum, Eurotium repens, Cladosporium tenuissimum, Fusarium fujikuroi, Aspergillus oryzae/flavus and Penicillium steckii were the predominant species. In case of sodium hypochlorite-treated soybeans, Eurotium herbariorum, E. repens and Cladosporium tenuissimum were the predominant species. Of the 4 genera and 86 species isolated from soybeans, 3 genera and 33 species were also found in Meju. Thirty-nine genera and 92 species were isolated from the rice straws and 40 species were identical with the species from Meju. Fusarium asiaticum, Cladosporium cladosporioides, Aspergillus tubingensis, A. oryzae, E. repens and Eurotium chevalieri were frequently isolated from the rice straw obtained from many factories. Twelve genera and 40 species of fungi that were isolated in the rice straw in this study, were also isolated from Meju. Especially, A. oryzae, C. cladosporioides, E. chevalieri, E. repens, F. asiaticum and Penicillium polonicum that are abundant species in Meju, were also isolated frequently from rice straw. C. cladosporioides, F. asiaticum and P. polonicum that are abundant in low temperature fermentation process of Meju fermentation, were frequently isolated from rice straw incubated at $5^{\circ}C$ and $25^{\circ}C$, while A. oryzae, E. repens and E. chevalieri that are abundant in high temperature fermentation process of Meju fermentation, were frequently isolated from rice straw incubated at $25^{\circ}C$ and $35^{\circ}C$. This suggests that the mycobiota of rice straw have a large influence in mycobiota of Meju. Thirty-nine genera and 92 species were isolated from the air of Jang factories and 34 species were identical with the species from Meju. In outside air of the fermentation room, Cladosporium sp. and Cladosporium cladosporioides were the dominant species, followed by Cladosporium tenuissimum, Eurotium sp., Phoma sp. Sistotrema brinkmannii, Alternaria sp., Aspergillus fumigatus, Schizophyllum commune, and Penicillium glabrum. In inside air of the fermentation room, Cladosporium sp., Aspergillus oryzae, Penicillium chrysogenum, A. nidulans, Aspergillus sp., C. cladosporioides, Eurotium sp., Penicillium sp., C. tenuissimum, A. niger, E. herbariorum, A. sydowii, and E. repens were collected with high frequency. The concentrations of the genus Aspergillus, Eurotium and Penicillium were significantly higher in inside air than outside air. From this results, the origin of fungi present on Meju was inferred. Of the dominant fungal species present on Meju, Lichtheimia ramosa, Mucor circinelloides, Mucor racemosus, and Scopulariopsis brevicaulis are thought to be originated from outside air, because these species are not or are rarely isolated from rice straw and soybean; however, they were detected outside air of fermentation room and are species commonly found in indoor environments. However, A. oryzae, P. polonicum, E. repens, P. solitum, and E. chevalieri, which are frequently found on Meju, are common in rice straw and could be transferred from rice straw to Meju. The fungi grow and produce abundant spores during Meju fermentation, and after the spores accumulate in the air of fermentation room, they could influence mycobiota of Meju fermentation in the following year. This could explain why concentrations of the genus Aspergillus, Eurotium, and Penicillium are much higher inside than outside of the fermentation rooms.

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Effects of Follicle Cells on the Chymotrypsin Resistance of Mouse Oocytes (난포세포가 생쥐 난자의 Chymotrypsin에 대한 내성에 미치는 영향)

  • Kim, Seong-Im;Bae, In-Ha;Kim, Hae-Kwon;Kim, Sung-Rye
    • Clinical and Experimental Reproductive Medicine
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    • v.26 no.3
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    • pp.407-417
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    • 1999
  • Objective: Mammalian follicle cells are the most important somatic cells which help oocytes grow, mature and ovulate and thus are believed to provide oocytes with various functional and structural components. In the present study we have examined whether cumulus or granulosa cells might playa role in establishing the plasma membrane structure of mouse oocytes during meiotic maturation. Design: In particular the differential resistances of mouse oocytes against chymotrypsin treatment were examined following culture with or without cumulus or granulosa cells, or in these cell-conditioned media. Results: When mouse denuded oocytes, freed from their surrounding cumulus cells, were cultured in vitro for $17{\sim}18hr$ and then treated with 1% chymotrypsin, half of the oocytes underwent degeneration within 37.5 min ($t_{50}=37.5{\pm}7.5min$) after the treatment. In contrast cumulus-enclosed oocytes showed $t_{50}=207.0$. Similarly, when oocytes were co-cultured with cumulus cells which were not associated with the oocytes but present in the same medium, the $t_{50}$ of co-cultured oocytes was $177.5{\pm}13.1min$. Furthermore, when oocytes were cultured in the cumulus cell-conditioned medium, $t_{50}$ of these oocytes was $190.0{\pm}10.8min$ whereas $t_{50}$ of the oocytes cultured in M16 alone was $25.5{\pm}2.9min$. Granulosa cell-conditioned medium also increased the resistance of oocytes against chymotrypsin treatment such that $t_{50}$ of oocytes cultured in granulosa cell-conditioned medium was $152.5{\pm}19.0min$ while that of oocytes cultured in M16 alone was $70.0{\pm}8.2min$. To see what molecular components of follicle cell-conditioned medium are involved in the above effects, the granulosa cell-conditioned medium was separated into two fractions by using Microcon-10 membrane filter having a 10 kDa cut-off range. When denuded oocytes were cultured in medium containing the retentate, $t_{50}$ of the oocytes was $70.0{\pm}10.5min$. In contrast, $t_{50}$ of the denuded oocytes cultured in medium containing the filtrate was $142.0{\pm}26.5min$. $T_{50}$ of denuded oocytes cultured in medium containing both retentate and filtrate was $188.0{\pm}13.6min$. However, $t_{50}$ of denuded oocytes cultured in M16 alone was $70.0{\pm}11.0min$ and that of oocytes cultured in whole granulosa cell-conditioned medium was $156.0{\pm}27.9min$. When surface membrane proteins of oocytes were electrophoretically analyzed, no difference was found between the protein profiles of oocytes cultured in M16 alone and of those cultured in the filtrate. Conclusions: Based upon these results, it is concluded that mouse follicle cells secrete a factor(s) which enhance the resistance of mouse oocytes against a proteolytic enzyme treatment. The factor appears to be a small molecules having a molecular weight less than 10 kDa.

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Role of HOXA Gene in Human Endometrial Decidualization (인간 자궁내막의 탈락막화에서 HOXA10 유전자의 역할)

  • Lee, Chang-Se;Park, Dong-Wook;Park, Chan-Woo;Kim, Tae-Jin
    • Clinical and Experimental Reproductive Medicine
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    • v.37 no.3
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    • pp.207-216
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    • 2010
  • Objective: This study was performed to clarify the role of HomeoboxA (HOXA) and its related signaling molecules in the decidualization of primary cultured endometrial cells. Methods: Human endometrial tissues were obtained by curettage of hysterectomy specimens from patients with conditions other than endometrial diseases. Tissues were minced and digested with Trypsin-EDTA for 20 min, $37^{\circ}C$. Cells were cultured with DMEM/F12 medium in $37^{\circ}C$, 5% $CO_2$ incubator for 24 hrs. Cells were treated with HOXA10 siRNA and added transforming growth factor (TGF)-${\beta}1$ (10 ng/mL) for 48 hrs to induces decidualization in vitro. Reverse transcription polymerase chain reaction analysis was accomplished to observe the expression of HOXA10, prolactin, cyclooxygenase (COX)-2, peroxisome proliferatoractivated receptor (PPAR)-$\gamma$, and wingless-type MMTV integration site family (Wnt). Results: HOXA10 expression was increased (1.8 fold vs. non-treated control) in TGF-${\beta}1$ treated cells. Decidualization marker, prolactin, was significantly increased in TGF-${\beta}1$ treated cells compared with HOXA10 siRNA treated cells. Endometrial cell differentiation marker, COX-2 was down-regulated by HOXA10 siRNA even if cells were treated with TGF-${\beta}1$. Wnt4 was down-regulated by treated with HOXA10 siRNA, this expression patters was not changed by TGF-${\beta}1$. Expression of PPAR-$\gamma$ was down regulated by TGF-${\beta}1$ in regardless of HOXA10 siRNA treatment. Conclusion: TGF-${\beta}1$ which is induced by progesterone in endometrial epithelial cells may induces stromal cell decidualization via HOXA10 and Wnt signaling cascade.

Promotion effects of steam-dried Betula platyphylla extract on hair regrowth (자작나무 증포 추출물의 발모 촉진 효과)

  • Ahn, Jeong Won;Jang, Su Kil;Jo, Bo Ram;Kim, Hyun Soo;Jeoung, Eui Young;Hillary, Kithenya;Yoo, Yeong Min;Joo, Seong Soo
    • Korean Journal of Food Science and Technology
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    • v.54 no.1
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    • pp.43-51
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    • 2022
  • Regulation of the hair follicle cycle in association with dermal papilla cells is one of the most interesting targets for promoting hair regrowth. In this study, we examined whether steam-dried Betula platyphylla extracts (BPE) promote hair growth by upregulating in vitro and in vivo responses of dermal papilla cells. The data showed that BPE3 contained high amounts of phenolic compounds with higher antioxidant effects and increased hair growth-related genes, including fibroblast growth factor7 and Wnt7b, in dermal papilla cells. Notably, BPE3 effectively enhanced the formation of hair follicles by increasing FGF7, Wnt7b, and vascular endothelial growth factor in C57BL/6N dorsal skins. Additionally, BPE3 significantly decreased the expression of inflammatory repertoires, inducible nitric oxide synthase, interleukin-6, and cyclooxygenase 2. Several small molecules, such as betulin and unsaturated fatty acids, support the pharmacological activity of BPE3. In conclusion, BPE3 effectively promoted hair growth by activating dermal papilla cells and enhancing hair follicle cycles by attenuating the inflammatory environment in the scalp.

Research on Immune Responses Induced by Salmonella Typhimurium Infectionin CRIP1-Deficient Condition (CRIP1결손조건 하에서 Salmonella Typhimurium 감염에 의해 유도되는 면역반응에 관한 연구)

  • Dongju Seo;Se-Hui Lee;Sun Park;Hyeyun Kim;Jin-Young Yang
    • Journal of Life Science
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    • v.34 no.1
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    • pp.48-58
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    • 2024
  • Salmonella is a common food-borne intracellular bacterial pathogen that has triggered significant public health concerns. Salmonella hosts' genetic factors play a pivotal role in determining their susceptibility to the pathogen. Cysteine-rich intestinal protein 1 (CRIP1), a member of LIM/double zinc finger protein family, is widely expressed in humans, such as in the lungs, spleen, and especially the gut. Recently, CRIP1 has been reported as a key marker of several immune disorders; however, the effect of CRIP1 on bacterial infection remains unknown. We aimed to elucidate the relationship between Salmonella infection and CRIP1 gene deficiency, as Salmonella spp. is known to invade the Peyer's patches of the small intestine, where CRIP1 is highly expressed. We found that CRIP1-deficient conditions could not alter the characteristics of bone marrow-derived myeloid cells in terms of phagocytosis on macrophages and the activation of costimulatory molecules on dendritic cells using ex vivo differentiation. Moreover, flow cytometry data showed comparable levels of MHCII+CD11b+CD11c+ dendritic cells and MHCII+F4/80+CD11b+ macrophages between WT and CRIP1 knockout (KO) mice. Interestingly, the basal population of monocytes in the spleen and neutrophils in MLNs is more abundant in a steady state of CRIP1 KO mice than WT mice. Here, we demonstrated that the CRIP1 genetic factor plays dispensable roles in host susceptibility to Salmonella Typhimurium infections and the activation of myeloid cells. In addition, differential immune cell populations without antigen exposure in CRIP1 KO mice suggest that the regulation of CRIP1 expression may be a novel immunotherapeutic approach to various infectious diseases.

Effect of Air Circulation Velocity on the Rate of Lumber Drying in a Small Compartment Wood Drying Kiln (소형 목재인공건조실에 있어서 공기순환속도가 목재건조율에 미치는 영향)

  • Chung, Byung-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.2 no.2
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    • pp.5-7
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    • 1974
  • 1. This study indicates that above the fiber saturation point the drying rate can be increased with increasing the velocity of the air circutation, i.e., the drying rate of sample boards is proportional to the air velocity, but below the fiber saturation point, the effect of the velocity of air circulation is very low as shown in Figs. 1 and 2. 2. Under the controlled temperature and humidity in the kiln, the more the sample boards have moisture, the higher drying rate of it can be obtained. In other words, this means that even though in the case of drying various moisture content of wood, at the final drying stage, approximately the same percentage of moisture content of wood can be secured by employing the higher velocity of air circulation. 3. This study shows that the rate of drying in kiln changes distinctly at the fiber saturation point, i, e., above the fiber saturation point, the drying curve shows concave aginst the X axsis, but below the fiber saturation point, in the range from 30 percent of moisture content to 20 percent of moisture content, the curve shows convex as shown in Fig. 3. As the drying progresses, however, the drying curve shows concave again below 20 percent of moisture content. This means that inflection point of drying curve may be located clearly at the fiber saturation point, i.e., 30 percent of moisture content. As mentioned above, the 30 percent of moisture content of wood at which the inflectional point appears can be recognized as a critical point, i. e., the fiber saturation point at which all free water was removed from wood. The existence of inflectional point indicates that the evaporation of hygroscopic water in a cell wall is more difficult than the evaporation of free water in a cell cavity and the minor space of cell wall. The convex curve in the range of moisture content from 30 percent to 20 percent means that the evaporation of capillary condensed water has a tendency of the same rates of drying approximately, but as approaching to the 20 percent of moisture, the transfusion of moisture from wood becomes difficult because of having less moisture in cell wall. Below 20 percent of moisture content, the drying curve shows concave again, which means that it is difficult to remove the moisture located nearer to the surface of cellulose molecules and the surface bound water. These relations were revealed in Fig. 4. In comparison AC curve which does not have the two inflection points with BD curve which has two inflection points, i.e., Band D, they are mentioned already, by existence of the inflection points, the curve BD shows that the change of drying rate in the interval from 20 percent of moisture content to 30 percent of moisture content is not greater than in the case of the curve AC in the same interval. At the inflection point of 30 percent of moisture content, it can be noticed that the changing of the drying rate is very conspicuous. This phenomenon also can be recognized, as it is noticed by the Fig. 3, the drying rate from green to 30 percent of moisture content is very great. But the inclination of the curve is very slow from 30 percent of moisture content to 20 percent of moisture content, i.e., the inclination of the curve becomes almost horizontal lines. Acknowledgments Gratitude is expressed to Fred E. Dickinson, Professor of 'Wood Technology, School of Natural Resources, University of Michigan, USA for his suggestion to carry out this study.

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