• Membrane Journal
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• v.24 no.6
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• pp.453-462
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• 2014

Thin film composite (TFC) polyamide (PA) membranes were prepared on polyester (PET) nonwoven reinforced polysulfone supports for forward osmosis (FO) processes. PSF (polysulfone) supports were prepared via the phase inversion process from PSF casting solutions in dimethyl formamide (DMF) solvents (19 wt%) by using a PET nonwoven (thickness of $100{\mu}m$) as a mechanical reinforcing material for reverse osmosis (RO) membrane. The PSF support from 19 wt% of DMF/PSF casting solution showed sponge-like morphology and asymmetric internal structure. To reduce the internal concentration polarization in FO operation, thin ($20{\mu}m$ of thickness) nonwoven-supported PSF supports were prepared by using PSF/DMF casting solution (9~19 wt%). A desirable support structure with a highly porous sponge-like morphology were achieved from the thin nonwoven-supported PSF layer prepared with 9~12 wt% casting solution. A crosslinked aromatic polyamide layer was fabricated on top of each support to form a TFC PA membrane. The tested sample from 12 wt% of DMF/PSF casting solution presented outstanding FO performance, almost 5.5 times higher water flux (24.3 LMH) with low reverse salt flux (RDF, 1.5 GMH) compared to a thick nonwoven rainforced membrane (4.5 LMH of flux and 3.47 GMH of RSF). By reducing the thickness of the nonwoven and optimizing PSF concentration of casting solution, the morphology of the prepared membranes were changed from a dense structure to a porous sponge structure in the boundary area between nonwoven and PET support layer.

• Journal of KIISE:Software and Applications
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• v.30 no.1_2
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• pp.19-30
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• 2003

Based upon XML, a standard document format on the web, there have been many active studies on e-Commerce, wireless communication, multimedia technology and so forth. JML is an XML application suitable for understanding and reusing the source code written using JAVA for various purposes. And it is a DTD which can effectively express various information related to hierarchical class structures, class/method relationships and so on. This paper describes a tool which generates JML document by extracting a comment information from Java source code and information helpful for reusing and understanding by JML in terms of the reverse engineering and a tool which generates a skeleton code of Java application program from the document information included in the automatically or manually generated JML document in terms of the forward engineering. By using the result of this study, the information useful and necessary for understanding, analyzing or maintaining the source code can be easily acquired and the document of XML format makes it easy for developers and team members to share and to modify the information among them. And also, the Java skeleton coed generated form JML documents is a reliable robust code, which helps for developing a complete source code and reduces the cost and time of a project.

• Membrane Journal
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• v.34 no.4
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• pp.205-215
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• 2024

The purpose of this paper was to preparation of organic solvent reverse osmosis (OSRO) membrane using a polyketone (PK) support. The PK support was prepared by non-solvent induced phase separation (NIPS) method, and a polyamide layer was interfacially polymerized on the PK support to fabricate OSRO membrane in the form of thin-film composite (TFC). After that, the surface and cross-sectional morphology of the OSRO membrane were analyzed, and the surface chemical structure of the membrane was analyzed. The water permeance and salt rejection of the OSRO membrane were about 1.28 LMH/bar and 99.0% respectively. The polyamide layer of the OSRO membrane was very stable during 1 day of organic solvent immersion, and the single organic solvent permeance trend was consistent with the organic solvent nanofiltration (OSN) membrane permeance model. The MWCO of the OSRO membrane is 240 g/mol in MeOH. The permeance and separation factor of the OSRO membrane for MeOH-toluene mixture were 200% and 60% higher than those of the commercial OSN membranes respectively.

• Journal of the Korean Chemical Society
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• v.50 no.3
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• pp.247-255
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• 2006

The purpose of this study was to investigate the correlation between concepts on chemical reaction rates and concepts on chemical equilibrium in high school students. The subjects of the investigation consisted of 120 third grade students attending high school in K city of Kyunggi province. For this study, questionnaire relevant to the subject of chemical reaction rates and chemical equilibrium was developed and the answers were analyzed. As a result of the study, a large percentage of high school students answered questions on reaction rates correctly, but only a small percentage of the students could give explanations. Many high school students answered questions on the rates of forward reactions correctly, but not the questions on the rates of reverse reactions. For the concepts on chemical equilibrium, many high school students gave correct answers when faced with equilibrium questions that only required the understanding of one side of the reaction. But the students could not answer the questions requiring understanding of both forward and reverse reactions as well. Overall, there was a little high correlation between concepts on chemical reaction rates and concepts on chemical equilibrium in high school students. Especially, high school students with little understanding of reverse reaction rates did not understand that chemical equilibrium is a dynamic equilibrium. Also, high school students with little understanding of the collision mechanism regarding chemical reaction rates did not understand the effect of concentration and catalyst factors on chemical equilibrium. And the correlation between concepts on chemical reaction rates and concepts on chemical equilibrium related to concentration and catalyst factors was low. In conclusion, the formation of scientific concepts on chemical reactions rates can decrease misconceptions on chemical equilibrium. Also the teaching-learning method limited to one side of a reaction can cause difficulty in forming the concepts on chemical dynamic equilibrium. Therefore, the development of a teaching-learning method which covers both the forward and reverse reactions can be effective in helping students form the concepts on chemical equilibrium.

• Structural Engineering and Mechanics
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• v.30 no.6
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• pp.733-761
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• 2008

The failure of reinforced concrete structures in recent earthquakes caused concern about the performance of beam column joints. Confinement of joint is one of the ways to improve the performance of beam column joints during earthquakes. This paper describes an experimental study of exterior beam-column joints with two non-conventional reinforcement arrangements. One exterior beam-column joint of a six story building in seismic zone III of India was designed for earthquake loading. The transverse reinforcement of the joint assemblages were detailed as per IS 13920:1993 and IS 456:2000 respectively. The proposed nonconventional reinforcement was provided in the form of diagonal reinforcement on the faces of the joint, as a replacement of stirrups in the joint region for joints detailed as per IS 13920 and as additional reinforcement for joints detailed as per IS 456. These newly proposed detailing have the basic advantage of reducing the reinforcement congestion at the joint region. In order to study and compare the performance of joint with different detailing, four types of one-third scale specimens were cast (two numbers in each type). The main objective of the present study is to investigate the effectiveness of the proposed reinforcement detailing. All the specimens were tested under reverse cyclic loading, with appropriate axial load. From the test results, it was found that the beam-column joint having confining reinforcement as per IS: 456 with nonconventional detailing performed well. Test results indicate that the non-conventionally detailed specimens, Type 2 and Type 4 have an improvement in average ductility of 16% and 119% than their conventionally detailed counter parts (Type1 and Type 3). Further, the joint shear capacity of the Type 2 and Type 4 specimens are improved by 8.4% and 15.6% than the corresponding specimens of Type 1 and Type 3 respectively. The present study proposes a closed form expression to compute the yield and ultimate load of the system. This is accomplished using the theory of statics and the failure pattern observed during testing. Good correlation is found between the theoretical and experimental results.

• 전기의세계
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• v.22 no.5
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• pp.19-32
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• 1973

This paper treats with some of plasma jet behaviors under magnetic field for the purpose of controlling important characteristics of plasma jet in the practices of material manufacturings. Under the existence and non-existence of magnetic field, the pressure distribution, flame length, stability and noise of plasma jet are comparatively evaluated in respect of such parameters as are current, gap of electrode, quantity of argon flow, magnetic flux density, diameter and length of nozzle. The results are as follows: 1) the pressure, the length and the noise of plasma jet rise gradually with the increase of are current, and have high values under identical arc current as the diameter of nozzle increases, but reverse phenomenon tends to appear in the noise. 2) The pressure, the flame length and the noise increase with the increased quantity of argon flow, and the rising slope of noise is particularly steep. Under magnetic field, the quantity of argon flow in respect of flame length has the critical value of 80(cfh). 3) The pressure and length of flame decrease with small gradient value as the length of gap increases, but the noise tends to grow according to the increase of nozzle diameter. 4) The pressure and the length of jet flame decrease inversly with the increase of magnetic flux density, which have one critical value in the 100 amps of arc current and two values in 50 amps. The pressure of jet flame can be below atomospher pressure in strong magnetic field. 5) "The constriction length of nozzle has respectively the critical value of 6(mm) for pressure and 23(mm) for the length of flame. 6) Fluctuations in the wave form of voltage become greater with the increase of argon flow and magnetic flux density, but tends to decrease as arc current increases, having the frequency range of 3-8KHz. The wave form of noise changes almost in parallel with that of voltage and its changing value increases with argon flow, arc current and magnetic flux density, having the freuqency range of 6-8KHz. The fluctuation of jet presurre is reduced with the increase of argon flow and magnetic flux density and grows with arc current.rent.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.24 no.4
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• pp.296-303
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• 2017

Purpose: The purpose of this study was to evaluate the reliability and validity of the Korean version of Diabetes Empowerment Measurement Scale Short Form (DES-SF) for use with diabetic patients in Korea. Methods: A cross-sectional descriptive study was used with 107 participants. Bilingual nursing professionals performed translation and reverse translation. Reliability and validity such as face validity, construct validity, and concurrent validity were conducted. To assess the concurrent validity, the correlation coefficients between the Korean version of the DES-SF and a concurrent scale (Diabetes Self-Efficacy Scale, DSES) were calculated. Results: In the explanatory factor analysis, a uni-dimension was proposed, the one factor accounted for 49.4% of total variances. The Korean version of the DES-SF correlated with a concurrent variable such DSES for reliability of the Korean version of the DES-SF, Cronbach's ${\alpha}=.85$. Conclusion: The findings show that the Korean version of the DES-SF is reliable and valid for evaluating empowerment in patients with diabetes in Korea.

• Journal of Veterinary Clinics
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• v.40 no.4
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• pp.308-313
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• 2023

A 1-year-old castrated male Korean Shorthair cat presented with dyspnea, anorexia, lethargy, and seizures. Physical examination revealed salivation, right forelimb hemiparesis, and rapid breathing. No abnormalities were detected on auscultation. Laboratory findings revealed increased levels of bilirubin, aspartate aminotransferase (AST), globulin, glucose, and a decreased albumin-to-globulin (A:G) ratio. Both N-terminal pro-B-type natriuretic peptide (NT-proBNP) and feline serum amyloid A (fSAA) levels were significantly elevated. Thoracic radiography revealed mild cardiomegaly and diffuse increased interstitial infiltration with soft tissue opacity in the periphery of the right caudal pleural space. Echocardiography and lung ultrasonography were performed to investigate the cause of mild cardiomegaly and soft tissue opacity in the pleural space. Echocardiography revealed a mild amount of echogenic pericardial effusion, and lung ultrasonography showed an echogenic soft tissue mass with no blood signal in the right caudal pleural space, suggestive of a granulomatous lesion. After obtaining 5 mL of pericardial fluid through pericardiocentesis, cytology of the pericardial effusion sample revealed marked neutrophils and macrophages with no bacteria. IDEXX feline infectious peritonitis (FIP) virus real-time reverse transcriptase polymerase chain reaction (RT-PCR) confirmed the presence of the FIP virus biotype in the sample. This case presents a rarely reported atypical mixed form of FIP in a cat diagnosed ante-mortem using pericardial effusion analysis. In this case, ultrasound examination played a crucial role in the definitive diagnosis of FIP by PCR biotyping through pericardiocentesis. Ultrasonography can be highly beneficial in guiding the diagnosis and evaluation of cats with suspected FIP.

• Korean Journal of Heritage: History & Science
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• v.43 no.3
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• pp.26-47
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• 2010

When the term conservation is used with regard to excavated features, it means not only conservation but also restoration. Restoring the features here does not imply restoring their original form but restoring their form at the moment of excavation. That means, the conservation of excavated features includes the concept of both reparation and restoration. The way of conserving excavated features can be largely categorized into on-site conservation and transfer conservation. On-site conservation means to conserve excavated features as they were at the excavation site. It can be further categorized into soil-covered on-site conservation, in which excavated features are covered with soil to prevent them from being damaged, and exposed on-site conservation in which the features were conserved as they were exposed. Transfer conservation is operated on the premise that excavated features are transferred to another place. It can be further categorized into original form transfer, transcribing transfer, reproduction transfer, and dismantlement transfer. Original form transfer refers to the method of moving the original forms of excavated features to another place. Transcribing transfer refers to moving some of the surfaces of excavated features to another place. Reproduction transfer refers to restoring the forms of excavated features in another place after copying the forms of excavated features at the excavation site. Dismantlement transfer refers to the method of restoring excavated features in a place other than the excavation site in the reverse order of dismantlement after dismantling the features at the excavation site. The most fundamental issue regarding conserving excavated features is the conservation of their original forms. However, the conservation of excavated features tends to be decided depending on a variety of conditions such as society, economy, culture, and local situations. In order to conserve excavated features more effectively, more detailed and specialized conservation methods should be created. Furthermore, continuing research is needed to find the most effective way of conserving them through exchange with other neighboring academic fields and scientific technology.

• Journal of Advanced Navigation Technology
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• v.1 no.1
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• pp.70-80
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• 1997

In this paper, the performances of two noncoherent code tracking loops, i. e., traditional code tracking loop(TCTL) and modified code tracking loop(MCTL) are analyzed and compared in a CDMA mobile environment. Closed-form formulas for steady-state jitter variance are derived analytically for the two schemes as a function of the pulse shaping filter, timing offset, signal-to-interference ratio, and loop bandwidth. The design issues of the loop filter are also addressed with emphasis on the second-order tracking loop. Finally, the degradation of BER performance due to timing errors is examined in a CDMA reverse link for IMT-2000 designed by ETRI.