• Title/Summary/Keyword: MDI

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Study on the Activation of Adhesion for the Manufacture of the Wood Based Panel Products (목질판상제품제조(木質板狀製品製造)를 위한 새로운 접착활성화(接着活性化)에 관한 연구(硏究))

  • Lee, Hwa-Hyoung
    • Journal of the Korean Wood Science and Technology
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    • v.19 no.4
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    • pp.18-26
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    • 1991
  • This study was carried out to examine not only the effect and the process of activation of aluminum sulfate for the manufacture of PB and MDF, but also application of the activation treatment to PB and MOF made with MDI adhesive. The results were as follows: 1. For the manufacture of PB, activating effect did not take place Because the low moisture content of 30% in the process of activation treatment made probably insufficient activation. It needs to examine higher moisture content for the uniform and enough activation same as that of MOF. 2. In the case of MOF, Activating effect was excellent, it showed not only better results of MOR 48%, MOE 29%, IB 60% than those of the control but also better dimensional stability. 3. Application of alum activation to the PB and MDF made with MDI adhesive yielded no effects. Maybe it was the reson that the curing mechanism of MDI is different. 4. Modifing the wood surface was the oxidation and wettability was not the variable limiting glueline performance. It is necessary to make a more study about activating reaction.

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Effect of PPG, MDI, 2-HEMA and butyl acrylate content on the properties of polyurethane adhesive (폴리우레탄 접착제의 물성에 미치는 PPG, MDI, 2-HEMA 및 butyl acrylate량의 영향)

  • Park, Chan Young
    • Elastomers and Composites
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    • v.49 no.3
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    • pp.245-252
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    • 2014
  • FT-IR measurement and the physical properties of polyurethane adhesive prepared from the polyol, isocyanate, 2-HEMA and other acrylate monomers were examined. The softening point, viscosity, adhesion strength and mechanical properties of the PU adhesives were reviewed by Ring and Ball method, Brookfield viscometer and universal test machine, respectively. Results revealed that increment of both PPG amount and butyl acrylate content decreased softening point, adhesion strength, tensile strength and 100% modulus. However as 2-HEMA and MDI content increased the mechanical properties including tensile strength, 100% modulus increased, and also the viscosity and NCO content increased.

K-BSID-II Performance in Normal and High Risk Infants : A Three Year Longitudinal Data Analysis (정상 영아 및 장애 위험 영아의 한국 Bayley 영유아발달검사(K-BSID-II) 수행 비교 : 3년 종단자료분석)

  • Park Choi, Hyewon
    • Korean Journal of Child Studies
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    • v.27 no.1
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    • pp.153-166
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    • 2006
  • Stability of the Korean Bayley Scale of Infant Development-II was tested in 305 infants by two measurements of varying intervals over a span of 5-36 months. Stability of K-BSID-II performance was r=.62(p<.01), r=.08(p<.18), r=.69(p<.01), r=.18(p<.01) for mental scale raw scores, mental scale index scores (MDI), psycho-motor scale raw scores and psycho-motor scale index scores(PDI), respectively. Stability was higher for the shorter test-retest interval group. Correlations between raw scores among infants with retest intervals of more than 2 years were stable on both mental and psycho-motor scales. MDI showed higher stability among high-risk infants than normal infants while PDI showed higher stability among normal infants. Testers and researchers should use both raw scores and index scores for better interpretations.

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Optimization of adipogenic differentiation conditions for canine adipose-derived stem cells

  • Kim, Jong-Yeon;Park, Eun-Jung;Kim, Sung-Min;Lee, Hae-Jeung
    • Journal of Veterinary Science
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    • v.22 no.4
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    • pp.53.1-53.13
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    • 2021
  • Background: Canine adipose-derived stem cells (cADSCs) exhibit various differentiation properties and are isolated from the canine subcutaneous fat. Although cADSCs are valuable as tools for research on adipogenic differentiation, studies focusing on adipogenic differentiation methods and the underlying mechanisms are still lacking. Objectives: In this study, we aimed to establish an optimal method for adipogenic differentiation conditions of cADSCs and evaluate the role of peroxisome proliferator-activated receptor gamma (PPARγ) and estrogen receptor (ER) signaling in the adipogenic differentiation. Methods: To induce adipogenic differentiation of cADSCs, 3 different adipogenic medium conditions, MDI, DRI, and MDRI, using 3-isobutyl-1-methylxanthine (M), dexamethasone (D), insulin (I), and rosiglitazone (R) were tested. Results: MDRI, addition of PPARγ agonist rosiglitazone to MDI, was the most significantly facilitated cADSC into adipocyte. GW9662, an antagonist of PPARγ, significantly reduced adipogenic differentiation induced by rosiglitazone. Adipogenic differentiation was also stimulated when 17β-estradiol was added to MDI and DRI, and this stimulation was inhibited by the ER antagonist ICI182,780. Conclusions: Taken together, our results suggest that PPARγ and ER signaling are related to the adipogenic differentiation of cADSCs. This study could provide basic information for future research on obesity or anti-obesity mechanisms in dogs.

Preparation and Properties of Polyurethane Dispersions with Aromatic/Aliphatic Mixed Diisocyanate (방향족/지방족 혼합 Diisocyanate를 포함하는 Polyurethane 분산체의 제조와 성질)

  • Kim, Hyoung Sug;Noh, Si Tae
    • Applied Chemistry for Engineering
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    • v.20 no.3
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    • pp.258-265
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    • 2009
  • An anionic polyurethane dispersions (PUDs) were synthesized from the poly (tetramethylene glycol) (PTMG, Mw = 2000 g/mol), mixed isocyanate of dicyclohexylmethane-4,4'-diisocyanate $(H_{12}-MDI)$ and 4,4'-diphenylmethane diisocyanate (MDI), and dimethylol propionic acid (DMPA) as anionic site, following a prepolymer mixing process. Triethylamine (TEA) was used as a neutralization agent and the ethylenediamine (EDA) as the chain extender of the prepolymer. The effects of the DMPA molar ratio and aromatic diisocyanate content in the mixed isocyanate on the particle size and viscosity of PUD were studied. Also, the mechanical and thermal properties of the PUD cast films were discussed according to the molar ratio of DMPA and aromatic isocyanate content. It was found that the particle size and the viscosity of an anionic PUD decreased with increasing DMPA molar ratio but increased with increasing aromatic isocyanate (MDI) content in the mixed isocyanate at the constant DMPA content. Tensile strength of the PUD cast films increased and elongation at break decreased with increasing DMPA content at the constant mixed isocyanate molar ratios. In thermal degradation temperature of PUD cast films, the effect of DMPA contents was great but the effect of aromatic isocyanate contents at the low DMPA content was very slight respectively.

Effects of Tracheal Suction and Method of Bronchodilator Inhalation on Vital Signs and Pulmonary functions in Patients with Open Heart Surgery(OHS) (심장수술 환아에게 기도흡인과 기관지 확장제의 투여 방법이 활력징후 및 폐기능에 미치는 효과)

  • Song Hyo-Sook;Jun Tae-Gook;Park Pyo-Won;Kim Kyoung-Eun;Chung Ji-Hye
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.10 no.1
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    • pp.96-107
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    • 2003
  • Objective: The purpose of this study was to identify the effects of tracheal suction and the effects of different methods of bronchodilator inhalation (Ultrasonic nebulizer: MDI puff, MDI puff with spacer) in VSD surgery patients. Material & Method: From June 2001 to March 2002, sixty consecutive patients were randomly assigned to a control group (n= 15), ultrasonic nebulizer group (n=15), metered dose inhalation (MDI) puff group (n=15) and MDI with spacer group (n=15). Vital signs (HR, BP, CVP), ABGA and pulmonary functions were measured before suction (baseline for suction), after suction, 15 minutes after suction (base of bronchodilator inhalation), 30 minutes after bronchodilator inhalation, and 2 hours after bronchodilator inhalation. Stastistical analysis was performed using SPSS software. Repeated measure ANOVA was used to examine the effects of tracheal suction. One way ANOVA with Bonferroni's correction and multiple range test (the least significant difference test) were used to examine the effects of albuterol inhalation. Result: 1. Heart .ate increased significantly immediately after suction (p<.01) and recovered 15 minutes after suction. 2. $PaO_2$ and PH decreased significantly immediately after suction (p<.05) and $PaO_2$ recovered 15 minutes after suction. $PaCO_2$ increased immediately after suction and significantly 15 minutes after suction (p<.01). But changes in vital signs and ABGA were within the normal range. 3. Tidal volume decreased significantly 15 minutes after suction (p<.05). 4. Changes of HR and tidal volume were greater in the nebuizer group compared to the other groups (p<.05) 30 minutes after bronchodilator inhalation and recovered 2 hours after bronchodilator inhalation. 5. Changes of airway deadspace was greater in the nebulizer group compared to the control group and MDI puff group 30 minutes after albuterol inhalation (p<.05) and at 2 hours (p<.01). Conclusion: Tracheal suction did not have significant effect on vital signs and pulmonary functions after OHS. Although the methods of bronchodilator inhalation did not showed any significant difference on pulmonary function, the nebulizer method increased $PaO_2$ (20%) and tidal volume transiently. If the patient needs bronchodilator inhalation with bronchospasm after OHS, the nebulizer method is the best choice. More study on the effects of bronchodilator inhalation in bronchospasm group is needed.

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Biological Monitoring of Workers Exposed to Diisocyanates using Urinary Diamines (소변 중 디아민을 이용한 디이소시아네이트 노출 근로자의 생물학적 모니터링)

  • Lee, Jong Seong;Kim, Boowook;Shin, Jungah;Baek, JinEe;Shin, Jae Hoon;Kim, Ji-hye
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.26 no.2
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    • pp.178-187
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    • 2016
  • Objectives: Diisocyanates are a potent inducer of diseases of the airways, especially asthma. In this study, toluenediamine(TDA) and methylenedianiline(MDA) in urine were evaluated as biomarkers of exposure to tolunenediisocyanate(TDI) and methylenediphenyl diisocyanate(MDI), respectively. Methods: Workers exposed to TDI and MDI, as well as non-occupationally exposed subjects, were studied and pre- and post-shift urine samples were collected from 8 control subjects and 8 workers from a factory which manufactures polyurethane products for reducing noise and vibration in automobiles. Airborne TDI and MDI(n=8) were sampled on solvent-free glass filters impregnated with n-butylamine and detected by liquid chromatography atmospheric pressure ionization tandem mass spectrometry. Urinary TDA and MDA were detected as pentafluoropropionic acid anhydride(PFPA) derivatives by liquid chromatography electrospray ionization tandem mass spectrometry. Results: The median levels of urinary 2,6-TDA(p<0.001), 2,4-TDA(p=0.001), and MDA(p<0.001) of workers in post-shift samples were significantly higher than those of controls. The median levels of urinary 2,6-0TDA($0.63{\mu}g/g$ creatinine vs $0.34{\mu}g/g$ creatinine, p=0.017) and MDA($4.21{\mu}g/g$ creatinine vs $3.18{\mu}g/g$ creatinine, p=0.017) of workers in post-shift samples were significantly higher than those of the pre-shift samples. There were significant correlations between the urinary 2,6-TDA, 2,4-TDA, and MDA of workers in post-shift samples and the airborne 2,6-TDI(rho=0.952, p<0.001), 2,4-TDI(rho=0.833, p=0.001), and MDI(rho=0.952, p<0.001). Conclusions: These urinary diamines, metabolites of diisocyanates, in post-shift samples were useful biomarkers to assess occupational exposure to diisocyanates.

Chemical Structure of Ozonized Waste Cooking Oil and Wood Bonding Strengths of Reaction Products with pMD (오존 처리한 폐식용유의 화학구조와 pMDI로 제조한 접착제의 목재 접착강도)

  • Kang, Chan-Young;Lee, Eung-Su;Ryu, Jae-Yun;Lee, Hyun-Jong;Seo, Jun-Won;Park, Heon
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.4
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    • pp.316-322
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    • 2010
  • The research attempted to develop a wood adhesive based on waste cooking oil, using ozonification technology for the chemical structure modification. The waste cooking oil (WCO) was reacted with $O_3$ for different times; 1 h, 2 h, and 3 h. The chemical structure modifications of the ozonized WCOs were examined by Fourier transform Infrared (FT-IR) spectrum. The FT-IR spectrum of WCO had an absorbance peak at 3,010 $cm^{-1}$ that was the characteristic peak of the unsaturated double bonds. As ozone treatment time increased, the peak of the double bond was disappeared and carboxyl peak appeared at 1,700 $cm^{-1}$. Especially, the double bond of 3 hrs-ozonized WCO was vanished almost. In results of the dry bonding strengths of the 3 hrs-ozonized WCO mixed with polymeric methylene diphenyl diisocyanate (pMDI) were the strengths of weight ratio of 3hrs-ozonized WCO : pMDI, 1 : 0.5, 8.08 kgf/$cm^2$, 1 : 0.75, 9.53 kgf/$cm^2$ 1 : 1, 44.16 kgf/$cm^2$, 1 : 2, 58.08 kgf/$cm^2$, 1 : 3, 61.41 kgf/$cm^2$, and 1 : 4, 46.95 kgf/$cm^2$. Therefore, it was found that the optimum equivalent ratio was formed at the ratio of 1 : 2 or 1 : 3. Under wetting the bonding strength of 1 : 3 ratio was appeared higher than that of 1 : 2 ratio, while the results obtained from hot-water and cyclic boiling shear test were similar.