• 한국대기환경학회지
• /
• 제17권4호
• /
• pp.331-345
• /
• 2001

The increase of carbon monoxide in the ambient air due to the emissions from point sources without control was estimated using three -dimensional numerical models. The target area was Ulsan where one of the largest industrial complexes was located. As a typical example using numerical models for air quality impact analysis of criteria pollutants that will determine whether the air quality standards would be exceeded or not, the following approaches were suggested. They include: (1) investigation of pre-existing atmospheric conditions, (2) identification of major factors causing high concentrations, (3) selection of episode days. (4) preparation of three-dimensional meteorological data, (5) confirmation of agreement between measured and predicted concentrations in the emission conditions of episode days, and (6) estimation of the impact due to changes of the emission conditions. In the present work, daily meteorological conditions for the specific period were classified into four clusters of distinctive features, and the episode days were selected individually from each cluster. Emphasis was placed on the selection of episodes representing meteorological conditions conducive to high concentrations especially for point sources that were sensitive to the wind direction variations.

• Mycobiology
• /
• 제42권2호
• /
• pp.93-99
• /
• 2014

The earliest pre-Linnaean fungal genera are briefly discussed here with special emphasis on the nomenclatural connection with the genus Cordyceps Fr. Since its valid publication under the basidiomycetous genus Clavaria Vaill. ex L. (Clavaria militaris L. Sp. Pl. 2:1182, 1753), the genus Cordyceps has undergone nomenclatural changes in the post-Linnaean era, but has stood firmly for approximately 200 years. Synonyms of Cordyceps were collected from different literature sources and analyzed based on the species they represent. True synonyms of Cordyceps Fr. were defined as genera that represented species of Cordyceps Fr. emend. G. H. Sung, J. M. Sung, Hywel-Jones & Spatafora. The most common synonyms of Cordyceps observed were Clavaria and Sphaeria Hall, reported in the 18th and in the first half of the 19th century, respectively. Cordyceps, the oldest genus in the Cordyceps s. s. clade of Cordycipitaceae, is the most preferred name under the "One Fungus = One Name" principle on priority bases.

• 한국의류학회지
• /
• 제3권2호
• /
• pp.9-14
• /
• 1979

As the fabric merchandises become more diversified and the pre-condensates of resin are used in increasing amount to enhance the quality of so-called 'easy care' in such fabric goods, form-aldehyde, which is extricated from nonwoven fabrics, has posed problems. The result of the study conformed, firstly that the fusible bonded webs sold in the current market contained a considerable amount of formaldehyde, i.e. the minimum of 552$\mu$g/g and the maximum of 2,123$\mu$g/g. Secondly, formaldehyde fond in many of such fabric goods was unable to be removed completely even after washed for, three times. Thirdly, the degree of permeation of HCHO into other part of the fabric proved to be high and. when kept in a poly bag over 10days. the amount of formaldehyde tended to increase. Such experiment, therefore, demonstrates that the methods of delivery and storage employed in the current distribution structure must be thoroughly re-examined. The conclusion of this study shows that we should be more concerned with the adverse effects of formaldehyde for the health of consumers. let alone the increase of export of such merchandises.

• 한국주조공학회지
• /
• 제25권5호
• /
• pp.203-208
• /
• 2005

The main emphasis of this study is to optimize the process variables for manufacturing aluminum foam materials by direct foaming of remelted aluminum scraps. Aluminum foams were fabricated from two different raw materials, pure aluminum and used beverage cans. For both cases, $TiH_{2}$ was used as a foaming agent. Calcium was added as a thickener for the foaming of pure aluminum and no thickener was added for that of used beverage Cans because the pre-existing oxides of the used beverage cans are used as a thickener. Calcium and $TiH_{2}$ content varies from 0.5wt.% to 2.0wt.% and from 0.5wt.% to 1.5wt.%, respectively. The processing conditions, such as the effect of calcium on the melt viscosity, foaming temperature, and the optimum amount of the foaming agent with regard to the melt viscosity were discussed.

• 한국학교수학회논문집
• /
• 제12권2호
• /
• pp.195-227
• /
• 2009

이 연구는 테크놀로지를 통합한 교사 교육 프로그램을 통하여 예비교사들이 TPCK 개발을 그리고 테크놀로지를 이용하여 학생들을 가르치는 동안 어떻게 그들이 실제교실에서 성공적이었는가를 묘사하였다. 다양한 자료들이 연구 문제를 해결하는데 정보를 제공하기 위해 사용되었다. 결국, 이 연구에서 교사교육 프로그램의 예비교사들이 TPCK를 이해하도록 돕는 것을 강조하는 것이 TPCK의 네 가지 요인에 의해 설명되어지는 예비교사들의 이해로 전이되었다. 하지만 신념, 교수, 테크놀로지 배경 다양성은 프로그램을 통하여 TPCK의 그들의 이해와 개발에 영향을 주었다.

• 영어어문교육
• /
• 제7권1호
• /
• pp.179-208
• /
• 2001

Using literary materials as resources for English learning rather than an object of literary study can be a genuine tool for the students to learn English in the form of oral and written communication. This case study treated the applications of a whole text to the overall course divided into pre-reading activities, while-reading activities, and post-reading activities and the applications of some partial passages extracted from various texts to teaching objectives with many levels of difficulty. This study found that literary texts could be good materials to teach the target language in EFL setting. The English-speaking students with little linguistic competence as a foreign language may be limited in learning English at first, but soon they can accelerate their linguistic competence by reinforcing the literary competence through the literary texts. To achieve effectively a desired goal through the use of literary texts as resources for language development several concrete techniques should be introduced: teacher-guided question strategies laying a central emphasis on the text itself, a problem-solving ability through student-centered activities, process-based and open-ended activities should be presented in a variety of ways using many appropriate activities according to teaching procedure with a careful selection of the texts.

• Earthquakes and Structures
• /
• 제14권6호
• /
• pp.599-614
• /
• 2018

This study focuses on the earthquake performance of two URM buildings having typical architectural configurations common for residential use constructed per pre-modern code in Albania. Both buildings are unreinforced clay brick masonry structures constructed in 1960 and 1984, respectively. The first building is a three-storey unreinforced one with masonry walls. The second one is confined masonry rising on five floors. Mechanical characteristics of masonry walls were determined based on experimental tests conducted according to ASTM C67-09 regulations. A global numerical model of the buildings was built, and masonry material was simulated as nonlinear. Pushover analyses are carried out to obtain capacity curves. Displacement demands were calculated according to Eurocode 8 and FEMA440 guidelines. Causes of building failures in recent earthquakes were examined using the results of this study. The results of the study showed that the URM building displays higher displacement and shear force demands that can be directly related to damage or collapse. On the other hand, the confined one exhibits relatively higher seismic resistance by indicating moderate damage. Moreover, effects of demand estimation approaches on performance assessment of URM buildings were compared. Deficiencies and possible solutions to improve the capacity of such buildings were discussed.

• Journal of the Korean Wood Science and Technology
• /
• 제45권2호
• /
• pp.232-242
• /
• 2017

The objective of this study was to examine changes in the porosity and internal structure of wood as it goes through the process of saccharification (extraction of fermentable sugars). This study also examined the use of different drying methods to prepare samples for characterization of internal pores, with particular emphasis on the partially disrupted cell wall. Aspen wood flour samples after dilute acid pretreatment followed by enzymatic hydrolysis were examined for nitrogen adsorption. The resulting isotherms were analyzed for surface area, pore size distribution, and total pore volume. Results showed that freeze drying (with sample pre-freezing) maintains the cell wall structure, allowing for examination of saccharification effects. Acid pretreatment (hemicellulose removal) doubled the surface area and tripled the total volume of pores, which were mostly 10-20 nm wide. Subsequent enzymatic hydrolysis (cellulose removal) caused a 5-fold increase in the surface area and a ~ 11-fold increase in the total volume of pores, which ranged from 5 to 100 nm in width. These results indicate that nitrogen adsorption analysis is a feasible technique to examine the internal pore structure of lignocellulosic residues after saccharification. The information on the pore structure will be useful when considering value-adding options for utilizing the solid waste for biofuel production.

• Advances in nano research
• /
• 제7권6호
• /
• pp.379-390
• /
• 2019

Putting emphasis on the effect of existence of porosity in the functionally graded materials (FGMs) on the dynamic responses of waves scattered in FG nanobeams resulted in implementation of a novel porosity-based homogenization method for FGMs and show its applicability in a wave propagation problem in the presence of axial pre-load for the first time. In the employed porosity-dependent method, the coupling between density and Young's moduli is included to consider for the effective moduli of the FG nanobeam by the means of a more reliable homogenization technique. The beam-type element will be modeled via the classical theory of beams, namely Euler-Bernoulli beam theory. Also, the dynamic form of the principle of virtual work will be extended for such nanobeams to derive the motion equations. Applying the nonlocal constitutive equations of Eringen on the obtained motion equations will be resulted in derivation of the nanobeam's governing equations. Depicted results reveal that the dispersion responses of FG nanobeams will be decreased as the porosity volume fraction is increased which must be noticed by the designers of advanced nanosize devices who are interested in employment of wave dispersion approach in continuous systems for specific goals.

• The Journal of Asian Finance, Economics and Business
• /
• 제8권2호
• /
• pp.497-503
• /
• 2021

The aim of this study is to determine the factors that affect customer satisfaction in the banking sector of Bangladesh because the economic growth and stability of a country depends on the soundness of its banking sector. The study tries to investigate and assess the quality of service on customer satisfaction in the banking sector. As a sample, data were collected from 382 respondents who were customers of 32 selected commercial banks of Bangladesh. A pre-structured questionnaire was used to collect the required data and information. OLS regression model and descriptive statistical tools were used to analyze data. The results of this study reveal that the quality of service (e.g., tangibility, reliability, and empathy) has a statistically significant impact on customer satisfaction. The results also show that there is a positive correlation between the customer satisfaction and service quality dimensions in the banking sector of Bangladesh. The present study finds that in the domestic banking industry the service quality dimensions (i.e., tangibility, reliability, and empathy) have significant positive impact on customer satisfaction. The findings of the present study suggest that Bank Supervisory Authority, Central Bank of Bangladesh, and Bank Management should give special emphasis to ensure maximum satisfaction of banks' customers.