• Title/Summary/Keyword: critical means

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Experimental and theoretical investigation of micellization behavior of sodium dodecyl sulfate with cetyltrimethylammonium bromide in aqueous/urea solution at various temperatures

  • Hoque, Md. Anamul;Mahbub, Shamim;Rub, Malik Abdul;Rana, Shahed;Khan, Mohammed Abdullah
    • Korean Journal of Chemical Engineering
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    • v.35 no.11
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    • pp.2269-2282
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    • 2018
  • Mixed micelle formation behavior of cationic surfactant-cetyltrimethylammonium bromide (CTAB) and anionic surfactant sodium dodecyl sulfate (SDS) in aqueous as well as in urea medium from 303.15 K to 323.15 K at 5 K interval was carried out by conductometric method. The differences between the experimental values of critical micelle concentrations (cmc) and ideal critical micelle concentrations ($cmc^{id}$) illustrate the interaction between the amphiphiles studied. The values of micellar mole fraction ($X_1^{Rub}$ (Rubingh), $X_1^M$ (Motomura), $X_1^{Rod}$ (Rodenas) and $X_1^{id}$(ideal) of surfactant CTAB determined by different proposed models and outcome indicate high involvement of CTAB in SDS-CTAB mixed micellization, which enhance by means of the augment of mole fraction of CTAB. The negative value of interaction parameter (${\beta}$) showed an attractive interaction involving CTAB and SDS. Activity coefficients were less than unity in all case, which also reveals the presence of interaction between CTAB & SDS. The negative ${\Delta}G^0_m$ values imply the spontaneous mixed micellization phenomenon. The attained values of ${\Delta}H^0_m$ were positive at inferior temperature, while negative at superior temperature. The negative ${\Delta}H^0_m$ values in urea ($NH_2CONH_2$) medium illustrate exothermic micellization process. The magnitudes of ${\Delta}S^0_m$ were positive in almost all cases. The excess free energy of mixed micelle formation (${\Delta}G_{ex}$) was found to be negative, which indicates the stability of mixed micelle as compared to the individual's components micelles.

The Lived Experiences of Patient's Families with the Intensive Care Unit Diary (환자 가족의 중환자실 일기 체험)

  • Jeong, Yu Jin;Ryoo, Sung Suk;Shin, Hyun Jeong;Yi, Young Hee
    • Journal of Korean Critical Care Nursing
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    • v.16 no.1
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    • pp.28-43
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    • 2023
  • Purpose : Intensive care unit (ICU) diaries have been implemented across the international ICU community. This study aimed to comprehend the meaning and nature of the lived experience of patients' families using the ICU diary in Korea. Methods : This qualitative study adopted van Manen's hermeneutic phenomenology. The participants comprised eight women and two men who were the family members of patients in the ICU for more than three days. Data were collected using in-depth interviews and observation from July 2018 to January 2019. Results : Patients' families who experienced the ICU diary recognized it with six beings according to time: a good idea, forgotten stuff, burdensome work, touching service, my stuff, and a thing in the memory. The ICU diary had three essential meanings for the families: communication, solace and hope, and a record of life. These findings were rearranged according to van Manen's fundamental existential, and the lived things and lived others were remarkably confirmed. Conclusion : Patients' families experienced various ICU diary forms over time and recognized an ICU diary as a means of communication. Therefore, the ICU diary is expected to be used as an intervention between families and healthcare providers in the ICU to support mutual communication.

Critical Success Factors for the Adoption of Health Management Information Systems in Public Hospitals in Zimbabwe

  • Caleb Manjeese;Indira Padayachee
    • Journal of Information Science Theory and Practice
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    • v.11 no.2
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    • pp.82-103
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    • 2023
  • The Zimbabwean healthcare sector faces huge challenges due to increased demands for improved services for a growing number of patients with fewer resources. The use of information and communications technologies, prevalent in many industries, but lacking in Zimbabwean healthcare, could increase productivity and innovation. The adoption of health management information systems (HMISs) can lead to improved patient safety and high-level patient care. These technologies can change delivery methods to be more patient focused by utilising integrated models and allowing for a continuum of care across healthcare providers. However, implementation of these technologies in the health care sector remains low. The purpose of this study is to demonstrate the advantages to be attained by using HMISs in healthcare delivery and to ascertain the factors that influence the uptake of such systems in the public healthcare sector. A conceptual model, extending the technology, organization, and environment framework by means of other adoption models, underpins the study of adoption behavior. A mixed method methodology was used to conduct the study. For the quantitative approach, questionnaires were used to allow for regression analysis. For the qualitative approach, thematic analysis was used to analyse interview data. The results showed that the critical success factors (namely, relative advantage, availability, complexity, compatibility, trialability, observability, management support, information and communication technology expertise, communication processes, government regulation, infrastructure support, organizational readiness, industry and competitive support, external support, perceived ease of use, perceived usefulness, attitude, and intention to use) influenced adoption of HMISs in public hospitals in Zimbabwe.

A Study of Quench Behaviors in YBCO Flims for Superconducting Fault Current Limiter (기포발생에 따른 초전도 한류기용 YBCO 박막 퀜치특성 연구)

  • Kang, J.S.;Park, K.B.;Lee, B.W.;Oh, I.S.;Kim, H.R.
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.796-798
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    • 2002
  • In these days, the interruption capability of some circuit breakers, which are installed in the transmission systems, is getting lower than the magnitude of the fault current because of continuous increase of power demand and relatively short power line which was installed in forms of mesh network As a result of these situations, fault current limiters (FCLs) are strongly necessary. There are various types which is investigated around the world, and new power apparatuses that have been newly considered and developed by many manufactures. In this paper, we considered resistive superconducting fault current limiters with YBCO thin films. The resistive limiters utilize a transition of YBCO films from superconducting to normal state caused by exceeding the critical current. By means of newly occurred impedance, the fault current will be limited effectively. Generally, a few current path patterns are available for YBCO films to enhance the current limiting performance of YBCO films. In this paper. the meander-type and the bi-spiral-type were used for current paths of YBCO flims. When YBCO films are quenched into the normal state, bubbles could be observed on the surface of YBCO films. Using our high-speed camera, the number of bubbles and the size of bubbles could be visualized and the relation between bubbles and current density was analyzed. By means of moving pictures of bubbles, we observed how the quench extended or how the heat was conducted in films.

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Significance and Limitations of Chinese Rural Villages Reconstruction - Focusing on the Critical Study on'Farmers' Upstairs(農民上樓)' Phenomenon - (중국 농촌마을 재편의 의의와 한계 - '농민상루(農民上樓)' 현상에 대한 비판적 고찰을 중심으로 -)

  • Park, Kyong-Cheol
    • Journal of Agricultural Extension & Community Development
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    • v.22 no.2
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    • pp.191-203
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    • 2015
  • The purposes of this study are to explain the background and significance of the 'Farmers' upstairs'(農民上樓) phenomenon which has been currently promoted as part of the "New Socialist Countryside Construction" in contemporary China, and its positive and negative aspects, and analyze the limitations of 'Farmers' upstairs'phenomenon. 'Farmers' upstairs'means the building of concentrated farmhouses by means of reconstruction of scattered farmhouses here and there, simultaneously by installing cultural, social welfare, and environmental facilities where rural farmer also could enjoy the convenience of urban living. It brings, however, the positive effects such as the improvement of living conditions of rural farmers, the simultaneously expanding of urban construction land and agricultural land, and the new influx of population from urban areas, whiles the negative effectives such as the forced demolition of farmhouses by governments or real estate developers with very lower compensation costs for the demolition of farmhouses, the gap from the standard of living, and above all, the inconvenience caused by the living in a multi-stories building in the rural villages. As a result, it is pointed out that the ongoing 'Farmers' upstairs', promoted as a kind of rural movement beyond a phenomenon, has similarities with the Rural Cooperative Movement(農村合作化運動) of Mao Zedong era(1953-61), namely the People's Commune Movement(人民公社運動) finally failed.

Hydrolysis of p-Nitrophenyl Carboxylic Ester in N,N-Dimethyl-N-dodecyl-N-(2-methylbenzimidazoyl) Ammonium Chloride Micellar Solution (N,N-Dimethyl-N-Dodecyl-N-(2-methylbenzimidazoyl) Ammonium Chloride 미셀 용액속에서 p-Nitrophenyl Carboxylic Ester의 가수분해)

  • Kim, Jeung-Bea;Kim, Hak-Yoon
    • Journal of Environmental Science International
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    • v.17 no.5
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    • pp.509-516
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    • 2008
  • New functional surfactant, N,N-dimethyl-N-dodecyl-N-(2-methyl benzimidazoyl) ammonium chloride(DDBAC) having benzimidazole(BI) functional group have been synthesized and the critical micellar concentration of DDBAC measured by surface tentiometry and electric conductivity method was $8.9{\times}10^{-4}M$. Micellar effects in DDBAC functional surfactant solution on the hydrolysis of p-nitrophenylacetate(p-NPA), p-nitro-phenylpropionate(p-NPP) and p-nitrophenylvalerate(p-NPV) were observed with change of various pH (Tris-buffer). The pseudo first rate constants of hydrolysis of p-NPA, p-NPP and p-NPV in optimum concentration of DDBAC solution increase to about 160, 280 and 600 times, respectively, as compared with those of aqueous solution at pH 8.00(Tris-buffer). It is considered that benzimidazole functional moiety accelerates the reaction rates of hydrolysis because they act as nucleophile or general base. In optimum concentration of DDBAC solution, the rate constants of hydrolysis of p-NPP and p-NPV increase to about 1.5 and 3.0 times, respectively, as compared with that of p-NPA. It means that the more the carbon numbers of alkyl group of substrates, the larger the binding constants between DDBAC micelle and substrates are. To know the hydrolysis mechanism of p-NPCE(p-NPA, p-NPP and p-NPV), the deuterium kinetic isotope effects were measured in $D_2O$ solutions. Consequently the pseudo first order rate constant ratios in $H_2O$ and $D_2O$ solution, $k_{H_2O}/k_{D_2O}$, were about $2.8{\sim}3.0$ range. It means that the mechanism of hydrolysis were proceeded by nucleophile and general base attack in approximately same value.

A Study on Meaning and Characteristics of Minimalism in Contemporary Architecture (현대건축에서의 미니멀리즘의 의미와 특성에 관한 연구)

  • 이정욱
    • Korean Institute of Interior Design Journal
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    • no.13
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    • pp.150-160
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    • 1997
  • The tendency of the Minimalism in the contemporary a architecture is based on Mies van der Rohe s saying ‘나SS IS m more" as the principle of the Minimal art and its formative c composition. It can be divided into technical Minimalism p prevailed in Northern Europe and the zone of German l language, and the regional one in Southern Europe and S Southern America. The former is interested in the experiences of the techniques and materials, and the latter in that of the s space and the place through the simple forms. The minialistic approach to the architecture is nat only m methodological one. It accepts the concept and the construction of architecture as 2 axes for making it keeps the tradition and c communication with the master builder, the materials, and i염 m means to compound. The expressive characteristics of works in M Minimalism are 1) as the formal issue, it is simple, self-referring. without any symbol or any allusion, and compounds the r repetitive forms as the comceptual aspec않 of architecture, 2) it h has the characteristies such as the approach directly to the m means by which architecture made, the critical interests to the m material attributes, and the capacity to the contemporary t technology as the issue of technique and materials, 3) regarding t the space and the place, it shows the good sense to the site in t the sphere intervention of architecture 1e Maininlalism architecture has i않 impotance in the point t that it seeks to the qualities immanent in architecture by s showing the marvelous status through discovering the i immanent properties of the site, program materials, and the s structure, and also it begins new way of interpreting a architecture with new viewpoint to the its essence as well as a architecture itself.self.

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The Effects of IT Service Management upon IT Service Management Performance: An Empirical Approach (IT 서비스 관리가 IT 서비스 관리 성과에 미치는 영향에 관한 실증 연구)

  • Kim, Min-Sun;Kim, Seung-Yoon;Lee, Seung-Joon;Lee, Jae-Beom
    • The Journal of Information Systems
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    • v.18 no.1
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    • pp.1-24
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    • 2009
  • Recently many companies have increased their investment in IT because they are increasingly interested in taking advantage of IT and they recognized that it was a very important strategic resource that any organization should manage. That means that the members of a company or an organization realized the importance of IT specialists' coordinating and working in partnership with the business employees to ascertain the high quality and productivity through IT services. While the company looks at IT cost reduction, there is a pressure from users for more support and service from IT departments. That means IT service providers have to offer improved service quality at reasonable cost. To solve the contradictory problem, this paper proposes the application of IT service management. If the IT service management is implemented properly, an organization can attain the tangible and intangible results which are profitable and effective. In Korea, studies on IT service management have focused only on getting a certification and development issues, and there are few papers which accomplished empirical studies. From the viewpoint of Resource-based theory, this study reviews the definition of IT service management and its elements. It has demonstrated empirically how IT service management can have an impact on IT service management performance. As a result, IT service management plays a role in adding and improving the practical use and efficiency of IT service management. In conclusion, this study contributes to support and show the critical point of the previous literatures about IT service management and offers the new practical implications for business sectors.

A Study on the Dyeing Method of the Dot-Patterned Costumes on the Mural Paintings of Goguryeo (고구려 고분벽화에 표현된 점문양 복식의 염색 연구)

  • Yang Kyung-Ae
    • Journal of the Korean Society of Costume
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    • v.54 no.7
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    • pp.55-62
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    • 2004
  • Research into the ancient dyeing and weaving culture is of critical importance to the fact that they constitute an integral part of the Korean costume. Due to the absence of the originals reflecting ancient costume cultures, it is difficult to figure out what the dyeing and weaving culture was like in ancient times. Because of limited visual materials available from the wall paintings of ancient tombs, studies conducted so far concerning the costume culture for the Goguryeo have focused on visual elements such as shape, structure, and type. As a result, research into ancient Korean dyeing and weaving cultures hasn't been properly made. Thanks to the presence of both some dyeing fabric originals from Goguryeo's neighboring countries and some visual materials like the wall paintings of the Goguryeo, it may be possible to obtain some clues to the dyeing and weaving culture. The dotted Pattern costumes were selected such as Muyongchong, No. 1 Jangcheon Tomb, Gakjeochong, Samsilchong, Ssangyeongchong, Susanri Tomb. According to a book titled ‘Hanwon’, the Goguryeo people manufactured fabrics in such a way that resist-dyed spots produced elaborate patterns over the purple fabric. It can be safely said that such dot patterns were produced by means of dyeing rather than weaving, because identical patterns aren’t well produced by means of painting and embroidery. Considering Goguryeo’s natural features, the dot patterns mentioned in historical literatures are thought to have been produced using animal’s skin. However, there is highest possibility that the dot Patterns were Produced using tie-resist dyeing or wax-resist dyeing techniques. With respect to the dyeing and weaving culture for the Goguryeo, one must refer to neighboring countries’ dyeing and weaving environments, given that the Goguryeo had engaged substantial cultural exchanges with China.

The Study on Analysis of the effect of introducing Bimodal Tram - Comparing with BRT - (바이모달 트램 도입 효과 분석에 관한 연구 - BRT와의 비교분석을 중심으로-)

  • Jang, Jun-Seok;Lee, Jun;Eom, Jin-Ki
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.739-744
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    • 2010
  • As recent traffic policy focuses on reduction of congestion and environmental contamination, with a catch phrase, 'Green Traffic', Low Carbon Green Growth' and 'Sustainable Development', introducing the new eco-friendly transport means including railway has been emerging as critical issue. Included in the new transport means are BRT, Bimodal Tram and LRT, and this study was intended to evaluate and analyze Bimodal, among others, which generates less emission, noise and vibration thanks to hybrid type traction system employed by Bimodal Tram, which is considered a future-oriented system because of eco-friendly features and cost efficiency as well as punctuality and convenient accessibility to bus. Thus in this study, appropriateness of Bimodal Tram comparing to other system(BRT) was suggested, using conversion traffic from the road, traffic speed and CO2 emission at the metropolitan area and large provincial areas as the barometer in evaluation, and furthermore, the measures applicable to introduction strategy that will meet various functional aspects in urban area in the coming days were developed.

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