• Title/Summary/Keyword: Space Component

Search Result 1,207, Processing Time 0.035 seconds

Formation of N2O in NH3-SCR DeNOxing Reaction with V2O5/TiO2-Based Catalysts for Fossil Fuels-Fired Power Stations (화력발전소용 V2O5/TiO2계 촉매상에서 NH3-SCR 탈질반응으로부터의 N2O 생성)

  • Kim, Moon Hyeon
    • Korean Chemical Engineering Research
    • /
    • v.51 no.2
    • /
    • pp.163-170
    • /
    • 2013
  • Selective catalytic reduction of $NO_x$ by $NH_3$ ($NH_3$-SCR) over $V_2O_5/TiO_2$-based catalysts is recently reported to be an anthropogenic emitter of $N_2O$ that is a global warming gas with a global warming potential of 310. Therefore, this review will get a touch on significance of some parameters regarding $N_2O$ formation in the $deNO_xing$ reaction for fossil fuels-fired power plants applications. The $N_2O$ production in $NH_3$-SCR reaction with such catalysts occurs via side reactions between $NO_x$ and $NH_3$ in addition to $NH_3$ oxidation, and the extent of these undesired reactions depends strongly on the loadings of $V_2O_5$ as a primary active component and the promoter as a secondary one ($WO_3$ and $MoO_3$) in the SCR catalysts, the feed and operating variables such as reaction temperature, $NO_2/NO_x$ ratio, oxygen concentration, gas hourly space velocity, water content and thermal excursion, and the physical and chemical histories of the catalysts on site. Although all these parameters are associated with the $N_2O$ formation in $deNO_xing$ reaction, details of some of them have been discussed and a better way of suppressing the $N_2O$ production in commercial SCR plants has been proposed.

Ecological Functions and Losses of Traditional Korean Village Groves

  • Lee, D.-W.;Park, C.-R.
    • The Korean Journal of Quaternary Research
    • /
    • v.18 no.2 s.23
    • /
    • pp.65-66
    • /
    • 2004
  • There have been groves, in many cases, along with hedgerows and remnant forests around a traditional Korean village. A village grove is very closely connected to the life of residents. Sometimes it was a holy place where important village festivals were held, and became a resting place for farmers, especially in sunny summer. As a matter of fact, it is noted that traditional Korean village groves had been fostered for many purpose as religion, Confucianism, scenery, sanitation, traffic guard, public security, agriculture, hunting, and military and public uses were included in Chosun Govemor General(1938). Village groves were usually located at the outlet of watershed inside which a village was built. In addition, village groves used to be established along part of mountain ranges, streams and streets. A unique type of village grove, called bibosoop was fostered especially where the outlet of watershed was largely opened. In other cases, it was placed where a part of mountain range was relatively low, or where village residents were likely to see ugly objects such as a huge cliff, stony upland with an unvegetated area and the like(Kim and Jang 1994). In a sense, a sheltebelt is a sort of bibosoop as it is a landscape element to complement places that are exposed to strong winds. However, it is comparable to other typical bibosoop that is situated at a topographically very specific zone of watershed. In this paper, we will address potential functions of Korean village groves from a perspective of modern landscape ecology and show current status of some remnants, based on preliminary surveys. A village grove functions as barrier or filter of objects such as water, nutrients, and other elements and habitat of wildlife (park et al. 2003, Lee 2004). The village grove slows down the flow of water and air, maintains soil moisture an hinders soil erosion, enabling cultivation of crops and bringing up creatures nearby. It contributes to enhancing biodiversity. Birds rest on shrubby and woody trees of the element. Presumably, other organisms may also inhabit the village groves and take advantage of it when those move from a forest patch to others. Emerging insects acclimate themselves in the shade of the green space before they fly to sunny air. Besides the village grove acts as a component of agroforestry system as leaf litter is shed from a grove to an asjacent agricultural area, and transformed into green manure(Lee 2004). By the way, many of the landscape elements were destroyed or declined in Koea during the past several decades. The losses have been parallel or linked to environmental degradation. Unfortunately, we have a little reliable data as for how many groves have disappeared in Korea until now. There has been no complete census on the village groves in Korea, and the viewpoints of survey were to a degree different depending on surveyors. So, it is difficult to analyze the temporal and spatial change of village groves. Currently, national inventory data of Korean village groves are available in three reports. We reviewed the locations of village groves and arranged those according to the present administrative units, DONG. With the limited data, we found that at least 484 of village groves were recorded in South Korea. Among all provinces, village groves were most in Gyeongsanbuk-Do Province and least in Chungcheongbuk-Do Province(Table 1). This is a preliminary report prepared while some quantitative data regarding functions and lossers of the village groves are being collected. More detailed data will be introduced in the near future.

  • PDF

A Study on the Bibliotherapeutic Values of Korean Folk-tales: Focused on Establishing and Analyzing their Situation for Multi-cultural Families (한국전래동화의 독서치료적 가치 연구 - 다문화가정을 위한 상황설정 및 상황분석을 중심으로 -)

  • Kim, Soo-Kyoung
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.46 no.3
    • /
    • pp.271-295
    • /
    • 2012
  • This study aims to extract and analyze the bibliotherapeutic values/situations of Korean folk-tales for multi-cultural families in Korea. By analyzing 27 stories in the Korean folk-tale picture book written in two languages(Korean & English), we can find out 5 kinds of situational analysis as follows: (1) There are more men than women by the biological sex factor, whereas there are more adults than younger persons by the biological age discrimination. (2) For the space concept, there are a lot of socially related stories in their surroundings. (3) In the vertical relationship, there are more conflict elements than in the horizontal one. (4) There are more helpers from the outside than in the inside circle for the solution of their problems. (5) As a story theme, greed, wisdom, belief and family component elements are greatly involved in the stories. Among their beliefs, there are a lot of wisdom and greed themes, while piety and royalty to parents and conflict against stepmothers are among the family components. All of these would be an archetype of Korean culture, which can play an important role not only to understand Korean lifestyle for the multi-cultural families, but also to learn and practice bibliotherapeutic values.

Robust Designs of the Second Order Response Surface Model in a Mixture (2차 혼합물 반응표면 모형에서의 강건한 실험 설계)

  • Lim, Yong-Bin
    • The Korean Journal of Applied Statistics
    • /
    • v.20 no.2
    • /
    • pp.267-280
    • /
    • 2007
  • Various single-valued design optimality criteria such as D-, G-, and V-optimality are used often in constructing optimal experimental designs for mixture experiments in a constrained region R where lower and upper bound constraints are imposed on the ingredients proportions. Even though they are optimal in the strict sense of particular optimality criterion used, it is known that their performance is unsatisfactory with respect to the prediction capability over a constrained region. (Vining et at., 1993; Khuri et at., 1999) We assume the quadratic polynomial model as the mixture response surface model and are interested in finding efficient designs in the constrained design space for a mixture. In this paper, we make an expanded list of candidate design points by adding interior points to the extreme vertices, edge midpoints, constrained face centroids and the overall centroid. Then, we want to propose a robust design with respect to D-optimality, G-optimality, V-optimality and distance-based U-optimality. Comparing scaled prediction variance quantile plots (SPVQP) of robust designs with that of recommended designs in Khuri et al. (1999) and Vining et al. (1993) in the well-known examples of a four-component fertilizer experiment as well as McLean and Anderson's Railroad Flare Experiment, robust designs turned out to be superior to those recommended designs.

Inhibitory Effect of Cordycepin on Human Platelet Aggregation

  • Cho, Hyun-Jeong;Ham, Hye-Seon;Lee, Tae-Kyung;Jung, Young-Jin;Park, Sun-A;Kang, Hyo-Chan;Park, Hwa-Jin
    • Biomedical Science Letters
    • /
    • v.10 no.1
    • /
    • pp.1-8
    • /
    • 2004
  • Cordycepin separated from Cordyceps militaris is a major physiologic active component in Cordyceps militaris. The platelet aggregation is stimulated by $Ca^{2+}$, which is either mobilized from intracellular endoplasmic reticulum or transported from extracellular space. cGMP antagonizes the actions of $Ca^{2+}$. Based on these facts, we have investigated the effects of cordycepin on the mobilization of $Ca^{2+}$ and the production of cGMP on collagen ($10\mu$g/ml)-induced human platelet aggregation. Cordycepin potently stimulated the human platelet aggregation induced by collagen ($10\mu$g/ml) in a dose-dependent manner. Cordycepin (500 $\mu$M) inhibited also the collagen-induced human platelet aggregation in the presence both 1 mM and 2 mM of $CaCl_2$. These are in accord with the results that cordycepin inhibited the $Ca^{2+}$- influx on collagen-induced human platelet aggregation. These results suggest that cordycepin decrease the intracellular $Ca^{2+}$ concentration to inhibit collagen-induced human platelet aggregation. Besides, cordycepin increased the level of cGMP on collagen-induced human platelet aggregation. This result is related with the decrease of intracellular $Ca^{2+}$ concentration, because cGMP inhibits the mobilization of $Ca^{2+}$. In addition, cordycepin inhibited the human platelet aggregation induced by LY -83583, inhibitor of guanylate cyclase. This result suggested that cordycepin inhibit the platelet aggregation by stimulating the activity of guanylate cyclase. In conclusion, we demonstrated that cordycepin might have the antiplatelet function by inhibiting $Ca^{2+}$-mobilization via the stimulation of the production of cGMP.

  • PDF

NIR as a tool for optimizing sampling time and studying batch dynamics.

  • Zeppelin, Joanna
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
    • /
    • 2001.06a
    • /
    • pp.1126-1126
    • /
    • 2001
  • The paper presented here is the initial part of a larger study, in which it was determined which quality parameters in cheese powder could already be predicted by NIR at an early stage in the process and which could only be predicted at the final stages of the process. This initial study was performed in order to establish the levels and nature of variation within and between batches such that the subsequent data collection could be tackled optimally. The perspectives evolved into more than was originally planned and revealed some interesting uses of NIR-technology. Cheese powder production starts as a batch process, where waste cheese from other dairies is melted down in a vat. The process then turns into a continual process as the vat is emptied and the melted cheese is then filtered, homogenized, pasteurized and finally spray dried. Between each batch the powder is to a greater or lesser degree a mixture of 2 batches. This paper is divided into 2 aspects, one regarding the optimization of sampling time and the other is a study of process dynamics. Optimizing sampling time This initial study included 9 powder samples from 9 different batches produced during one day. The raw materials for the batches were chosen with the aim of creating a relatively high level of variation in the data. The total of 81 samples were taken out at regular intervals and spectra were collected on a NIR-systems 6500 instrument. The subsequent reduction of the data by PCA to score values shows the power of NIR as a tool to determine not only when samples are representative of a certain batch, but also which batches are stable enough to include in a further study. Studying process dynamics To take this experiment a step further 1 of the 81 samples were sent to the laboratory for further analyses. The samples were chosen on the criteria that they covered the spectral variation in the dataset. These samples were analysed for 4 chemical components and 5 physical attributes, which are essential for describing the quality of the product. The latent structure of the 7 samples, using the chemical and physical variables, is totally comparable to the latent structure of the NIR spectra. This outcome makes it possible to describe the dynamics of one day's production both chemically and physically with relatively little resources. Additionally it raises the question as to whether reference values are needed, as the latent structure of the NIR-spectra appears to be sufficient in providing information on the quality of the product. To be able to use NIR in this way would require defining quality limits in the principal component space as opposed to each of the reference values. The potential of NIR applied in an explorative fashion with batch processes opens a whole new gateway for the use of this technology. This study explains yet again after so many years in the field “why I'm crazy about NIR!”.

  • PDF

Verifying ASCE 41 the evaluation model via field tests of masonry infilled RC frames with openings

  • Huang, Chun-Ting;Chiou, Tsung-Chih;Chung, Lap-Loi;Hwang, Shyh-Jiann;Jaung, Wen-Ching
    • Earthquakes and Structures
    • /
    • v.19 no.3
    • /
    • pp.157-174
    • /
    • 2020
  • The in-situ pushover test differs from the shake-table test because it is performed outdoors and thus its size is not restricted by space, which allows us to test a full-size building. However, to build a new full-size building for the test is not economical, consequently scholars around the world usually make scale structures or full-scale component units to be tested in the laboratory. However, if in-situ pushover tests can be performed on full-size structures, then the seismic behaviors of buildings during earthquakes can be grasped. In view of this, this study conducts two in-situ pushover tests of reinforced concrete (RC) buildings. One is a masonry-infilled RC building with openings (the openings ratio of masonry infill wall is between 24% and 51%) and the other is an RC building without masonry infill. These two in-situ pushover tests adopt obsolescent RC buildings, which will be demolished, to conduct experiment and successfully obtain seismic capacity curves of the buildings. The test results are available for the development or verification of a seismic evaluation model. This paper uses ASCE 41-17 as the main evaluation model and is accompanied by a simplified pushover analysis, which can predict the seismic capacity curves of low-rise buildings in Taiwan. The predicted maximum base shear values for masonry-infilled RC buildings with openings and for RC buildings without masonry infill are, respectively, 69.69% and 87.33% of the test values. The predicted initial stiffness values are 41.04% and 100.49% of the test values, respectively. It can be seen that the ASCE 41-17 evaluation model is reasonable for the RC building without masonry infill walls. In contrast, the analysis result for the masonry infilled RC building with openings is more conservative than the test value because the ASCE 41-17 evaluation model is limited to masonry infill walls with an openings ratio not exceeding 40%. This study suggests using ASCE 41-17's unreinforced masonry wall evaluation model to simulate a masonry infill wall with an openings ratio greater than 40%. After correction, the predicted maximum base shear values of the masonry infilled RC building with openings is 82.60% of the test values and the predicted initial stiffness value is 67.13% of the test value. Therefore, the proposed method in this study can predict the seismic behavior of a masonry infilled RC frame with large openings.

Methodology of Shape Design for Component Using Optimal Design System (최적설계 시스템을 이용한 부품에 대한 형상설계 방법론)

  • Lee, Joon-Seong;Cho, Seong-Gyu
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.1
    • /
    • pp.672-679
    • /
    • 2018
  • This paper describes a methodology for shape design using an optimal design system, whereas generally a three dimensional analysis is required for such designs. An automatic finite element mesh generation technique, which is based on fuzzy knowledge processing and computational geometry techniques, is incorporated into the system, together with a commercial FE analysis code and a commercial solid modeler. Also, with the aid of multilayer neural networks, the present system allows us to automatically obtain a design window, in which a number of satisfactory design solutions exist in a multi-dimensional design parameter space. The developed optimal design system is successfully applied to evaluate the structures that are used. This study used a stress gauge to measure the maximum stress affecting the parts of the side housing bracket which are most vulnerable to cracking. Thereafter, we used a tool to interpret the maximum stress value, while maintaining the same stress as that exerted on the spot. Furthermore, a stress analysis was performed with the typical shape maintained intact, SM490 used for the material and the minimizing weight safety coefficient set to 3, while keeping the maximum stress the same as or smaller than the allowable stress. In this paper, a side housing bracket with a comparably simple structure for 36 tons was optimized, however if the method developed in this study were applied to side housing brackets of different classes (tons), their quality would be greatly improved.

The Commercialization of Blockbuster Exhibitions in Museums (미술관 블록버스터 전시의 상업주의적 경향 연구)

  • Hwang, Kyung-Ja
    • The Journal of Art Theory & Practice
    • /
    • no.2
    • /
    • pp.191-213
    • /
    • 2004
  • The trend of "Blockbuster Exhibitions" over the past decade has led to the unfortunate reality that museums, losing sight of their role as an Academic organization, are becoming increasingly influenced by the corporate world. In my dissertation entitled "The Commercialization of Blockbuster Exhibitions in Museums," I explore the modern tendency toward Blockbuster exhibitions in art museums and the negative impact of those exhibitions on the art world. Museums of the modern day have expanded their territory from the traditional venue of public education to the hybrid cultural space. This mission, evident in the museum's attempt to satisfy audiences with the offering of diverse activities, has changed the concept of the museum, giving priority to the desire for financial gain. From the viewpoint of this new museology, the museum considers Blockbuster exhibitions as the safest method to increase ticket sales. As a program that openly reveals the commercialism of the museum, I explore the Blockbuster show and its strategies as a means of exposing the influence of the corporate world on art. A key component to the Blockbuster exhibition is the "hype" that is created to attract an audience. This devotion to increased publicity distracts from what should be the goal of public education, as the primary focus leans towards the desire for a large number of visitors. Consequently, this unavoidably standardized exhibition is presented to the public in a manner that deprives the audience of a unique experience. With large crowds and increased ticket prices, it is difficult to form a genuine appreciation of the artwork. In addition to the profit gained by increased ticket prices and the commercial sales of "souvenirs" from the museum gift shop, Blockbuster shows are used as a means to attract the attention of corporate sponsors. As explained in my dissertation, the importance that the museum places on corporate sponsorship as a capital resource is evident, however the degree to which the museum allows itself to he influenced by the desire for capital gain poses a threat to its function as an academic organization. Circumstances in American museum history, in particular, have influenced the transition from academic resource to corporation within museology. In keeping with the nation's tendency towards capitalism, art museums in the United States were initially established and developed by individual capitalists who applied principals of corporate operation to museum management. As a result, in modern days, We witness the influence of enterprise on museum programs, while corporate management may be able to guarantee immediate fiscal benefits, however, it is unable insure the future of the museum. In Slim, my dissertation discusses the mechanism of the commercialized "Blockbuster Exhibition" and the impact that it has on the future of the museum as an industry. This research provides an opportunity to reconsider the role of the museum as an academic institution, particularly in regard to the need to decrease the capitalization of exhibitions and refocus their influence on the art world as an educational resource.

  • PDF

Remote Seabed Classification Based on the Characteristics of the Acoustic Response of Echo Sounder: Preliminary Result of the Suyoung Bay, Busan (측심기의 음향반사 특성을 이용한 해저퇴적물의 원격분류: 부산 수영만의 예비결과)

  • Kim Gil Young;Kim Dae Choul;Kim Yang Eun;Lee Kwang Hoon;Park Soo Chul;Park Jong Won;Seo Young Kyo
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.35 no.3
    • /
    • pp.273-281
    • /
    • 2002
  • Determination of sediment type is generally based on ground truthing. This method, however, provides information only for the limited sites. Recent developments of remote classification of seafloor sediments made it possible to obtain continuous profiles of sediment types. QTC View system, which is an acoustic instrument providing digital real-time seabed classification, was used to classify seafloor sediment types in the Suyoung Bay, Pusan. QTC View was connected to 50 kHz echo sounder, All parameters of QTC View and echo sounder are uniformly kept during survey. By ground truthing, the sediments are classified into seven types, such as slightly gravelly sand, slightly gravelly sandy mud, gravelly muddy sand, clayey sand, sandy mud, slightly gravelly muddy sand, and rocky bottom. By the first remote classification using QTC View, four sediment types are clearly identified, such as slightly gravelly sand, gravelly mud, slightly gravelly muddy sand, and rocky bottom. These are similar to the result of the second survey. Also the result of remote classification matches well with that of ground truthing, but for sediment type determined by minor component. Therefore, QTC View can effectively be used for remote classification of seafloor sediments.