• Membrane Journal
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• v.14 no.2
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• pp.132-141
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• 2004

NBR-Clay hybrid membranes were prepared by melt intercalation method with internal mixer and two roll mills. MMT was intercalated or ekfoliated by the NBR and it was confirmed by X-ray diffraction method. D-spacing of the characteristic peak from MMT plate in WAXD was moved and diminished. Gas permeability, mechanical properties and thermal properties of the NBR-Clay hybrid membranes were investigated. Gas permeability through the NBR-Clay hybrid membranes decreased due to increased tortuosity made by intercalation of clay in NBR.

• Advances in concrete construction
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• v.12 no.5
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• pp.439-450
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• 2021

In recent years, nano-reinforcing materials are widely utilized in cement composites due to their unique multifunctional properties. This study incorporated multi-walled carbon nanotubes (MWCNTs) into the cementitious composites at ratios of 0.1%, 0.3%, and 0.5%, and investigated their influence on the flowability, mechanical strength, and hydration heat properties. The addition of MWCNTs enhanced the compressive and split tensile strengths approximately by 18-51%. In the semi-adiabatic temperature rise test, the internal hydration heat of the composites reduced by 5%, 9%, and 12% with the increase of MWCNTs in 0.1%, 0.3%, and 0.5%. This study further performed hydration heat analysis and estimated the adiabatic temperature rise, thermal stress, and thermal crack index. The internal hydration heat of the concrete decreased by 5%, 10%, and 13% with the increase of MWCNTs. The thermal stress of the concrete decreased with increase in the addition of MWCNTs, and the obtained temperature crack index was effective in controlling the thermal cracks.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.19 no.2
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• pp.130-145
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• 2006

Objectives : The aim of this work is the approaching of properties-flavours theory and the making of morphological standard in Artemisiae herba. Methods : The properties-flavours theory were attempted with bibliographic method and various climate-information. The external-internal morphological standards were determined by using stereoscope and butanol series. Conclusions : The following is a list the conclusion of the approaching of properties-flavours theory and how to make the standard of morphological standard in artemisiae herba. 1. The significant analysis for the artemisiae herba as the properties-flavours theory, is a follow-up survey of the effect written in the official oriental medicine book 2. The other analytic methods according to the gathering time, processing or storing system or especially nature or growth environment(altitude, temperature,. the mean moisture, and the agronomical survey) by way of the explanation of properties-flavours theory appears so many insufficiency at the many cases. 3. In the case of artemisiae herba., there are 2 cases(Artemisia capillaris $T_{HUNB}$ and A. iwayomogi $K_{ITAMURA}$) in current and recently A. aruwa L. is substituted for artemisiae herba in circulation. 4. The external and internal characteristics according to the shape of original plant or herbal states, entirely correspond to all the official oriental medicine boo 5. According to the place of productiot the difference appeals. (1) A. capillatis $T_{HUNB}$. has leaves like a fine thread, and A. iwayomogi $K_{ITAMURA}$ has big and wide leaves, and shows some reddish color, and A. aruwa L. has narrow leaves, its section lines long vertically. (2) In the internal shapes, as the A. capillatis $T_{HUNB}$. leaves', upper epidermal cell wall shows relatively straight form, its all upper- lower epidemical cell wall has a stoma, and calcium rosette crystal is relatively few. As iwayomogi $K_{ITAMURA}$, all upper- lower epidermal cell wall is wavelike concave, and hypodermics has many stoma and many calcium rosette crystal. (3) In the internal shapes of A. aruwa L. the shape of leaves' epidermal cell is irregular and has so many non-glandular hair nad glandular hair on its surface.

• Journal of Biosystems Engineering
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• v.28 no.2
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• pp.157-166
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• 2003

The purpose of this study is to characterize the internal physical properties of fresh Korean ginsengs (Panax ginseng C.A. Meyer) through a magnetic resonance imaging (MRI) technique. Current external visual inspection cannot determine internal quality of ginsengs successfully. Relaxation time constants, T$_1$ and T$_2$*, were obtained from a series of MR images. Calculated Ti values were varied with different physiological states of ginseng tissues. Internal imaging information was obtained nondestructively from fresh ginsengs. One- and two-dimensional image analyses were performed. One-dimensional image analysis showed a potential of age identification of ginsengs rapidly. Internal quality of normal and abnormal ginsengs was evaluated using two-dimensional MR images. Various types of internal defects such as internal cavity and rotten spot were visualized clearly. The MRI technique had a feasibility to detect internal defects of fresh ginsengs effectively.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.867-875
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• 2020

Quality internal audit (IA) plays a crucial role in accountability, transparency and preserving public properties. This paper gives a brief background of the IA system in Yemen and examines its impact with regards to financial performance in Yemeni commercial banks based on five factors: (i) independence of IAs, (ii) adherence to IA standards, (iii) governance principles implementation, (iv) size of the IA, and (v) frequency of internal audits committees' meetings. The primary data for the study were collected through a questionnaire prepared for this purpose. Fifty questionnaires were distributed out of which forty-two were retrieved and valid in the analysis process. For the empirical analysis, descriptive analysis and T-test were used for verification of the research hypotheses. Results revealed that sticking to standards internal audit, internal auditors' independence and quality governance have significant impact on banks' financial performance, while the size of internal audits committees, as well as their meeting, frequently has insignificant positive impact on banks' performance. Moreover, the country results show that the use of automated internal audit in banks has an impact on improving financial performance. This article provides avenues for further studies, mainly in developing countries, including Yemen, in quality internal audit and financial performance.

• Polymer(Korea)
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• v.38 no.3
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• pp.351-357
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• 2014

In membrane covered stent, occlusion and fracture from membrane degradation by gastric acid sometimes occurred. Therefore, we investigated the physical properties of membrane covered stent according to its ingredient and concentration in gastric acid environment. Membrane covered stents consisted of silicone and polyurethane with 15%, 18%, 20% concentrations were used. After incubating stents in a condition of pH 1.2, we checked any changes at every 3 weeks for 18 weeks. The changes of membrane surface, radial expansion and recovery force of stent were investigated. Coating thickness increased proportionally to an increase in ingredient concentration. Surface was evenly coated with silicone compared to the case with polyurethane and its homogeneity was excellent in a high concentration. Degradation was much severe in the case of polyurethane. The radial force of silicone was higher than polyurethane, and the decrease of radial and recovery force was higher in the case of polyurethane. In conclusion, high concentration of silicone membrane was more stable than polyurethane in acid environment of in vitro study.

• Journal of the Korean Wood Science and Technology
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• v.19 no.1
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• pp.71-80
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• 1991

This study was carried out to investigate replaceable species with the conventional sounding board sitka spruce. by comparing the dynamic properties such as density, dynamic Young's modulus and internal friction Dynamic Young's modulus. internal friction of longitudinal and radial direction measured in free mass-free boundary condition for facile vibration analysis and measured by forced vibration method. Dynamical properties of four species were measured on squared plate specimen that the four edges were hung vertically by threads and driven magnetically through an iron piece glued on the specimen, by the use of condenser microphone as vibration transducer, and analyzed by FFT analyzer. The results obtained were as follows: 1. Chaldni method using aluminum powder was proper to identify the vibration mode in the plate vibration and it was possible to verify the resornance mode. 2. It was considered that it was necessary to investigate the influence of adhesive part on the plate vibration when the sounding board was made by two or three small board adhesion. 3. It was considered that plate vibration method, which was a superior to the vibration test of beam, was suitable for selecting suounding board because dynamic Young's modulus and internal friction show different order according to longitudinal and radial direction. 4. Paulownia tomentosa Thunb.) Steudel has been considered to be replaceable species with sitka spruce because it has high dynamic Young's modulus compared with low density, low internal friction, and K value of Paulownia tomentosa (Thunb.) Steudel is greater than that of sitka spruce.

• Tuberculosis and Respiratory Diseases
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• v.74 no.2
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• pp.79-81
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• 2013

Few recent reports have indicated that Mycobacterium massiliense causes various infections including respiratory infection. However, there is scarce information on the clinical significance, natural history of the infection, and therapeutic strategy. This report describes a case of an immunocompetent old man infected by M. massiliense that causes acute respiratory failure. In light of the general courses of non-tuberculous mycobacterium infections, rapid progression and fatality are very rare and odd. In addition, we discuss the biological and pathological properties of M. massiliense with the review of cases reported previously including our fatal one.

• The Journal of Internal Korean Medicine
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• v.32 no.2
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• pp.243-258
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• 2011

Objectives : This study investigated the hypolipidemic and antioxidant effects of Curcuma radix using a rat model induced by poloxamer 407 injection. Methods : Serum lipid parameters and oxidative stress-associated biomarkers were determined. Additionally, hepatic cholesterol and triglyceride as well as lipid metabolism-associated gene expressions were observed in hepatic tissue. Results : 1. Curcuma radix ameliorated elevation of serum cholesterol, triglyceride, LDL-cholesterol, MDA, hepatic cholesterol level, and reduction of serum TAC, SOD, GSH, GSH-reductase level. 2. Curcuma radix augmented up-regulated ACAT gene expression. 3. Curcuma radix almost completely ameliorated down-regulated CYP-7A1 but up-regulated HMG-CoA gene expression. Conclusions : The hypolipidemic and antioxidant properties of Curcuma radix were evidenced. This study provides a scientific basis for the clinical application of Curcuma radix and development of hypolipidemics using this herb in the future.

• Journal of the Korean Geotechnical Society
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• v.28 no.12
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• pp.77-86
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• 2012

We have carried out a series of numerical experiments to study the effect of average particle size on the mechanical properties of granite-derived weathered soils. A distinct-element method was adopted to study the changes in macro-scale mechanical properties with particle size and maximum-to-minimum particle size ratio. The numerical soil specimen with cohesion values of 0.25 MPa and internal friction angle of 29 degrees was prepared for reference. While keeping the porosity values constant, we varied particle size and size distribution to study how cohesion and internal friction angle changes. The experimental results show that the values of cohesion apparently decrease with increasing particle size. Changes in the values of internal friction angles are small, but there is a trend of increase in internal friction angle as the average particle size increases. This study demonstrates a possibility that the results of numerical experiments of this type may be used for rapid estimation of mechanical properties of granite-derived weathered soils. For example, when mechanical properties obtained through in situ tests and particle size data obtained through lab analysis are available for a site, it is expected that the mechanical properties of weathered granite soils with varying degrees of weathering (thus, varying particle size) may be estimated rapidly only with particle size data for that site.