• Title/Summary/Keyword: contact effect

Search Result 3,294, Processing Time 0.031 seconds

Studies on the Surface Changes and Adhesion of EVA Foam by Plasma Treatment (플라즈마 처리에 의한 EVA Foam의 표면변화 및 접착특성에 관한 연구)

  • Choi, Myung Jin;Kim, Dong Ho;Kim, Gu Ni
    • Journal of Adhesion and Interface
    • /
    • v.9 no.1
    • /
    • pp.9-15
    • /
    • 2008
  • EVA foam was treated by oxygen plasma under a various treatment time for surface modification. The effect of plasma treatment on surface properties of EVA foam was investigated in terms of FT-IR ATR, XPS, contact angle, and SEM analysis and the adhesion characteristic of the EVA foam was studied in peel strength. As a results, EVA foam treated by plasma led to an elimination of organic compound, an increase of oxygen content, and an increase of surface roughness, resulting in improving the adhesion properties of the EVA foam. As the plasma treatment time increased, the hydrophilicity and physical change of surface of the EVA foam were increased and showed maximum value at 180 s and 420 s, respectively. The maximum adhesion strength appeared at plasma treatment time of 420 s and therefore, in this study the physical change was thought to be a major factor for improving the adhesion of the EVA foam.

  • PDF

Fabrication of Super-hydrophobic Surface using Solubility Difference of Polystyrene at Two Different Solvents (두 용매에서의 폴리스타이렌의 용해도 차이를 이용한 초소수성 표면 제조)

  • Jung, Jin-Suk;Park, Kwang-Bae;Choi, Ho-Suk
    • Clean Technology
    • /
    • v.14 no.1
    • /
    • pp.35-39
    • /
    • 2008
  • In this study, we successfully fabricated a super-hydrophobic polymer layer on the surface of slide glass using the solubility difference of a polymer at two different solvents. After dissolving polystyrene (PS) resins in tetrahydrofuran (THF) as a good solvent and then adding ethanol(EtOH) as a poor solvent, we were able to fabricate super-hydrophobic surface. We also investigated the effect of EtOH addition, coating methods, solution mixing time and speed, and other alcohols on the surface hydrophobicity. The water contact angle (WCA) of the fabricated surface revealed $WCA>150^{\circ}$ and the microporous surface structure composed of microparticles with the size less than $5\;{\mu}m$.

  • PDF

The Effects of Kangaroo Care on Anxiety and Confidence and Gratification of Mothering Role in Mothers of Low Birth Weight Infants (캉가루식 돌보기가 저출생체중아 어머니의 불안, 역할 수행에 대한 자신감 및 만족감에 미치는 효과)

  • Moon Young Im;Koo Hyun Young
    • Child Health Nursing Research
    • /
    • v.6 no.3
    • /
    • pp.281-290
    • /
    • 2000
  • This study was performed to investigate the effect of kangaroo care on anxiety and confidence and gratification of mothering role in mothers of low birth weight infants. The subjects were 30 mothers of low birth weight infants, sixteen for the kangaroo care group and fourteen for the control group, whose infants hospitalized in two neonatal intensive care unit at two university-affiliated hospital. The kangaroo care was applied 9 times during the twenty six days with 40 minutes for each session. The kangaroo care provides the skin-to-skin contact during which a low birth weight infant wearing a diaper and a hat is placed on its mother's chest. The questionnaire, state anxiety was completed before beginning the first intervention. The questionnaire, state anxiety and confidence and gratification of mothering role were completed at 2 weeks after discharge. The data were analyzed by a SPSS program. The results were as follows : 1. There were no significant differences in the state anxiety between the kangaroo care and the control group before beginning the first intervention. The state anxiety was significantly lower in kangaroo care group than in control group. 2. The confidence of mothering role was significantly higher in kangaroo care group than in control group at 2 weeks after discharge. 3. The gratification of mothering role was significantly higher in kangaroo care group than in control group at 2 weeks after discharge. 4. In mothers of low birth weight infants, the state anxiety was negatively correlated to the confidence of mothering role and the gratification of mothering role at 2 weeks after discharge. And the confidence of mothering role in mothers of low birth weight infants was positively correlated to the gratification of mothering role at 2 weeks after discharge. These results suggest that kangaroo care is an effective nursing intervention for mothers of low birth weight infants in reducing the state anxiety, improving the confidence and gratification of mothering role.

  • PDF

Racemic and enantiomeric effect of tartaric acid on the hydrophilicity of polysulfone membrane

  • Sharma, Nilay;Purkait, Mihir Kumar
    • Membrane and Water Treatment
    • /
    • v.7 no.3
    • /
    • pp.257-275
    • /
    • 2016
  • The enantiomeric and racemic effects of tartaric acid (TA) on the properties of polysulfone (PSn) ultrafiltration membranes were studied in terms of morphology and hydrophilicity (HPCT) of membrane. Asymmetric membranes were prepared by direct blending of polyvinyl pyrrolidone (PVP) with D-TA and DL-TA in membrane casting solution. FTIR analysis was done for the confirmation of the reaction of PVP and TA in blended membranes and plain PSn membranes. Scanning electron microscope (SEM), field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM) were used for analyzing the morphology and structure of the resulting membranes. The membranes were characterized in terms of pure water flux (PWF), hydraulic permeability and HPCT. PWF increased from $52L/m^2h$ to $79.9L/m^2h$ for plain and D-TA containing PSn membrane, respectively. Water contact angle also found to be decreased from $68^{\circ}$ to $55^{\circ}$. In Additionally, permeation and rejection behavior of prepared membranes was studied by bovine serum albumin (BSA) solution. A considerable increase in BSA flux (from $19.1L/m^2h$ for plain membrane to $32.1L/m^2h$ for D-TA containing membrane) was observed. FESEM images affirm that the pore size of the membranes decreases and the membrane permeability increases from 0.16 to 0.32 by the addition of D-TA in the membrane. D-TA increases the HPCT whereas; DL-TA decreases the HPCT of PSn membrane. PVP (average molecular weight of 40000 Da) with D-TA (1 wt%) gave best performance among all the membranes for each parameter.

Effect of Diamond-Like Carbon Passivation on Physical and Electrical Properties of Plasma Polymer (플라즈마 폴리머의 물리적, 전기적 특성에서 다이아몬드상 탄소 패시베시션이 미치는 영향)

  • Park, Y.S.;Cho, S.J.;Boo, J.H.
    • Journal of the Korean Vacuum Society
    • /
    • v.21 no.4
    • /
    • pp.193-198
    • /
    • 2012
  • In this study, we have fabricated the polymer insulator and diamond-like carbon (DLC) thin films by using plasma enhanced chemical vapor deposition methods. we fabricated the DLC films with various thicknesses as the passivation layer on plasma polymer and investigated the structural, physical, and electrical properties of DLC/plasma polymer films. The plasma polymer synthesized in this work had the low leakage current and low dielectric constant. The values of hardness and elastic modulus in DLC/plasma polymer films are increased, and the value of rms surface roughness is decreased, and contact angle value is increased with increasing DLC film thickness. In the electrical properties of DLC/plasma polymer, the value of the dielectric constant is increased, however the leakage current property of the DLC/plasma polymer is improved than that of plasma polymer film with increasing DLC film thickness.

Effect of Treatment Conditions of Eco-friendly Fluorinated Water-repellent Agent and Design Applications: Silk Fabrics with DTP Finishing (나노잉크 및 반응성잉크를 사용한 DTP 견직물의 친환경 불소계 발수제에 의한 가공효과 연구)

  • Choi, Kyungme;Kim, Jongjun
    • Journal of Fashion Business
    • /
    • v.18 no.5
    • /
    • pp.159-170
    • /
    • 2014
  • Recent concerns about the PFOA(perfluorooctanoic acid), have been increasing, which is generally applied in the water-repellent finishing process of textile products. It has been proven through animal testing to be harmful to humans, as possible carcinogens and neuro-toxic material. Thus U. S. Environmental Agency has gone as far as requiring the material to be eliminated in its entirety by 2015. As a viable alternative to this water-repellent finishing agent, the development of C6 product is gaining its popularity. The effects of PFOA finishing on the silk fabrics were examined, and we reviewed parameters of the needed process for optimizing appearance and functionality of silk fabrics treated with eco-friendly water-repellent finishing agent. Cross-linking agent affected the most on black color of reactive ink, among the physical properties. The contact angle reading was the highest in $8g/{\ell}$ of concentration for all fabrics. All the fabric specimens, subjected to the DTP and water repellent finishing, exhibited higher stiffness, where rayon specimen showed the highest, compared to the untreated specimens. The results may provide basic information leading to the development of value-added silk fabrics with water-repellency without excessive deterioration of the delicate appearance and inherent soft touch.

Reflection on Kinetic Models to the Chlorine Disinfection for Drinking Water Production

  • Lee, Yoon-Jin;Nam, Sang-ho
    • Journal of Microbiology
    • /
    • v.40 no.2
    • /
    • pp.119-124
    • /
    • 2002
  • Experiments for the characterization of inactivation were performed in a series of batch processes with the total coliform used as a general indicator organism based on the chlorine residuals as a disinfectant. The water samples were taken from the outlet of a settling basin in a conventional surface water treat- ment system that is provided with the raw water drawn from the mid-stream of the Han River, The inactivation of total coliform was experimentally analysed for the dose of disinfectants contact time, filtration and mixing intensity. The curves obtained from a series of batch processes were shaped with a general tailing-off and biphasic mode of inactivation, i.e. a sharp loss of bacterial viability within 15 min followed by an extended phase. In order to observe the effect of carry-over suspended solids on chlorine consumption and disinfection efficiency, the water samples were filtered, prior to inoculation with coliforms, with membranes of both 2.5$\mu$m and 11.0 $\mu$m pore size, and with a sand tilter of 1.0 mm in effective size and of 1.4 in uniformity coefficient. As far as the disinfection efficiency is concerned, there were no significant differences. The parameters estimated by the models of Chick-Wat-son, Hom and Selleck from our experimental data obtained within 120 min are: log(N/N$\_$0/)=-0.16CT with n=1, leg(N/N$\_$0/)=-0.71C$\^$0.87/ with n 1 for the Chick-Watson model, log (N/N$\_$0/)=-1.87C$\^$0.47/ T$\^$0.36/ for the Hom model, log (MHo)=-2.13log (1+CT/0.11) for the Selleck model. It is notable that among the models reviewed with regard to the experimental data obtained, the Selleck model appeared to most closely resemble the total coliform survival curve.

Effect of Conductive Additives in La0.8Sr0.2MnO3 Perovskite Electrodes for Oxygen Reduction and Evolution in Alkaline Solution (알칼리용액에서 La0.8Sr0.2MnO3 페롭스카이트 촉매의 산소환원 및 발생반응에서 도전재의 영향)

  • SHIM, JOONGPYO;LOPEZ, KAREEN J.;YANG, JIN-HYUN;SUN, HO-JUNG;PARK, GYUNGSE;EOM, SEUNGWOOK;LEE, HONG-KI
    • Journal of Hydrogen and New Energy
    • /
    • v.27 no.3
    • /
    • pp.276-282
    • /
    • 2016
  • The effects of conductive additives in a $La_{0.8}Sr_{0.2}MnO_3$ perovskite bifunctional electrode for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) were investigated in an alkaline solution. Highly porous carbon black (CB) and Ni powder were added to the bifunctional electrodes as conductive additives. The surface morphologies of electrodes containing CB and Ni were observed by scanning electron microscopy (SEM). The current densities for both ORR and OER were changed by the addition of CB. The conductive additive changed physical properties of bifunctional electrodes such as the sheet conductance, gas permeability and contact angle. It was observed that the air permeability of electrode was most effective to enhance the currents for ORR and OER.

Levofloxacin and Torsades de Pointes (Levofloxacin과 Torsades de Pointes)

  • Kwon, Se-Ah;Kim, Cheol-Hong;Song, Won-Jun;Koo, Ja-Kyung;Lee, Soon-Jae;Park, Ji-Young;Hyun, In-Gyu;Ko, Jang-Hyu;Kim, Hyun-Soo
    • Tuberculosis and Respiratory Diseases
    • /
    • v.69 no.6
    • /
    • pp.474-479
    • /
    • 2010
  • Torsades de pointes associated with a prolonged QT interval is a life-threatening arrhythmia, which may be induced by any of the following: drugs, electrolyte imbalances, severe bradycardia and intracranial hemorrhage. Torsades de pointes is characterized by beat-to-beat variations in the QRS complexes in any ECG leads with rates of 200~250 per minute. Fluoroquinolones are widely used and well tolerated antibacterial agents. However, prolongation of the QT interval leads rarely to Torsades de pointes as a significant adverse effect. So, it should be used with caution in high-risk patients for developing Torsades de pointes. We report one case of 67-year old man with contact burns who experienced Torsades de pointes, which probably resulted from the use of levofloxacin, and no further episode occurred after its withdrawal.

Children's social relationships, psychological characteristics, and behavior problems (아동의 사회적 관계 및 심리적 특성과 문제 행동의 관계)

  • Choi, Yu-Jung;Choi, Set-Byol
    • Journal of the Korean Home Economics Association
    • /
    • v.45 no.1
    • /
    • pp.75-89
    • /
    • 2007
  • This study investigates the effects of children's social relationships and psychological characteristics on their behavior problems. Behavior problems comprise violations of norms, bullying, and deviant behavior in the cyberspace. A data set of 2949 Korean children in their 4th grade is analyzed to yield three main results. First, variables such as contact with delinquent friends, aggressiveness, stress of appearance complex, gender, and depression have significant effects on violations of norms. Children who have more delinquent friends, higher level of aggressiveness, stress of appearance complex, or depression report more violations of norms. Second, delinquent friends, stress of peer relationship, aggressiveness, stress of appearance complex, gender, parents' violent attitudes toward children, and negative self-image are turned out to be important variables predicting bullying. Children with more delinquent friends, higher level of stress, higher level of aggressiveness, or lower self-image are more likely to experience bullying. Children who perceive their parents to be violent show more bullying experience. Third, each of aggressiveness, delinquent friends, stress of appearance complex, gender, relationship with teacher, and family income has significant effect on deviant behavior in cyberspace. Children with higher level of aggressiveness, more delinquent friends, stress of appearance complex, or negative impression of teacher are more likely to deviate in cyberspace. Children from higher income families report more deviant behavior in cyberspace. Boys show more experiences in every category of behavior problems than girls.