• Membrane and Water Treatment
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• v.4 no.2
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• pp.83-93
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• 2013

In the present investigation, were synthesized composite membranes prepared by simultaneous casting of two polymer solutions using the technique of phase inversion by immersion / precipitation. The support layer was prepared using polyethersulfone and polysulfone as base polymer and for the top layer was used sulfonated polysulfone (SPSU) with 50% sulfonation degree. The morphology of the resulting membranes were characterized by scanning electron microscopy (SEM). The final results showed that it is possible to prepare composite membranes by simultaneous casting of two polymer solutions with adherence between the two layers. Regarding the permeation tests, the developed membranes presented values of hydraulic permeability within the range of commercial nanofiltration (NF) membranes. Values rejection of 80% ammonium ions can be increased by using a SPSU with a greater degree of sulfonation.

• Structural Engineering and Mechanics
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• v.3 no.5
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• pp.411-427
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• 1995

The most known continuum damage theories for brittle structures are suitable to model the degradation of the material due to the deformation process and the consequent initiation of a macro-crack. Nevertheless, they are not able to describe the propagation of the crack that leads, eventually, to the breakage of the structure into parts that undergo rigid body motion. This paper presents a theory, formulated from formal arguments of Continuum Mechanics, that may describe not only the degradation but also the fracture of elastic structures. The modeling of such a discontinuous phenomenon through a continuous theory is possible by taking a cohesion variable, related with the links between material points, as an additional degree of kinematical freedom. The possibilities of the proposed theory are discussed through examples.

• Journal of Industrial Technology
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• v.20 no.B
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• pp.139-146
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• 2000

To support Quality of Service (QoS) in the existing Internet, Differentiated Service (Diff-Serv) has been proposed. But, the unfairness between TCP connections remains as a serious problem not only in the conventional best-effort service Internet but also in new Diff-Serv network. In this paper, we propose the Balancing Marker Algorithm (BMA) improving the fairness between individual connections of aggregated sources in a Diff-Serv network. This algorithm is based on the 3-level priority marking method. We compared the 2-level packet priority marker with the Balancing Marker proposed in this paper. And we showed that the BMA improved the fairness and the throughputs between the individual connections with different delays in an aggregated source.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.9
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• pp.765-770
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• 2003

We have developed a low-temperature, and low-pressure radical induced oxidation (RIO) technology, so that high-quality ultrathin silicon dioxide layers have been effectively produced with a high reproducibility, and successfully employed to realize high performace SiGe heterostructure complementary MOSFETs (HCMOS) lot the first time. The obtained oxide layer showed comparable leakage and breakdown properties to conventional furnace gate oxides, and no hysteresis was observed during high-frequency capacitance-voltage characterization. Strained SiGe HCMOS transistors with a 2.5 nm-thick gate oxide layer grown by this method exhibited excellent device properties. These suggest that the present technique is particularly suitable for HCMOS devices requiring a fast and high-precision gate oxidation process with a low thermal budget.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.273-281
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• 2022

Mantle heterogeneity is closely related to the distribution and circulation of volatile components in the Earth's interior, and the behavior of volatiles in the mantle strongly influences the rheological properties of silicate rocks. In mantle xenoliths, these physicochemical properties of the upper mantle can be recorded in the form of microstructures and fluid inclusions. In this paper, I summarized and reviewed the results of previous studies related to the characteristics of microstructures and fluid inclusions from peridotite xenoliths beneath the Rio Grande Rift (RGR) in order to understand the evolution and heterogeneity of upper mantle. In the RGR, the mantle peridotites are mainly reported in the rift axis (EB: Elephant Butte, KB: Kilbourne Hole) and rift flank (AD: Adam's Diggings) regions. In the case of the former (EB and KB peridotites), the type-A lattice preferred orientation (LPO), formed under low-stress and low-water content, was reported. In the case of the latter (AD peridotites), the type-C LPO, formed under low-stress and high-water content, was reported. In particular, in the case of AD peridotites, at least two fluid infiltration events, such as early (type-1: CO₂-N₂) and late (type-2: CO₂-H₂O), have been recorded in orthopyroxene. The upper mantle heterogeneity recorded by these microstructures and fluid inclusions is considered to be due to the interaction between the North American plate and the Farallon plate.

• Advances in Energy Research
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• v.6 no.1
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• pp.17-33
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• 2019

This study aimed to observe trends in the literature on research, development, and innovation management in the energy sector, using performance assessment systems. The paper presented a bibliometric analysis of 40 studies on the subject. These materials come from ScienceDirect, Scopus and the Institute of Electrical and Electronics Engineers (IEEE) databases from 2006 to 2016. The results showed an increasing trend in the number of publications on the theme, showing the scientific community's interest in the subject. In addition, it was verified that the predominant language used to write the publications was English, the country that most published articles in the area was Brazil and most of the articles were produced through collaboration between researchers. It was found that the journal with the greatest number of publications on the subject was the Procedia - Social and Behavioral Sciences, while the Expert Systems with Applications journal presented the article with the greatest number of citations. This analysis allowed us to identify important points of the research and its future directions, in addition to enabling a better understanding of the world trend of the subject approached.

• Advances in nano research
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• v.10 no.3
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• pp.211-219
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• 2021

The evaluation of the corrosion resistance of titanium with a TiO2 nanotubes top layer was carried out (TiO2 NT). These nanostructures were evolved into anatase nanoparticles without heat treatment in an aqueous medium, which is a novel phenomenon. This work analyzes the layer between the nanotube bottom and the substrate, which is thin and still susceptible to corrosion. The bottom of TiO2 nanotubes having Fluor resulting from the synthesis process changed between amorphous to crystalline anatase with a crystallite size of about 4 nm, which influenced the corrosion rates. Four kinds of samples were evaluated. A) NT by Ti anodizing; B) NTSB for Ti plates, either modifying its surface or anodizing the modified surface; C) NT-480 for anodized Ti and heat-treated (480℃) for reaching the anatase phase; D) NTSB-480 for Ti plates, first, modifying its surface using sandblast, after that, anodizing the modified surface, and finally, heat-treated to 480℃ to compare with samples having induced crystallization and passivation. Four electrochemical techniques were used to evaluate the corrosion rates. The surfaces having TiO2 nanotubes with a sandblast pre-treatment had the highest resistance to corrosion.

• The Journal of Advanced Prosthodontics
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• v.7 no.6
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• pp.468-474
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• 2015

PURPOSE. The aim of this study was to characterize and compare bacterial diversity on the removable partial denture (RPD) framework over time. MATERIALS AND METHODS. This descriptive pilot study included five women who were rehabilitated with free-end mandibular RPD. The biofilm on T-bar clasps were collected 1 week ($t_1$) and 4 months ($t_2$) after the RPD was inserted ($t_0$). Bacterial 16S rDNA was extracted and PCR amplified. Amplicons were cloned; clones were submitted to cycle sequencing, and sequences were compared with GenBank (98% similarity). RESULTS. A total of 180 sequences with more than 499 bp were obtained. Two phylogenetic trees with 84 ($t_1$) and 96 ($t_2$) clones represented the bacteria biofilm at the RPD. About 93% of the obtained phylotypes fell into 25 known species for $t_1$ and 17 for $t_2$, which were grouped in 5 phyla: Firmicutes ($t_1=82%$; $t_2=60%$), Actinobacteria ($t_1=5%$; $t_2=10%$), Bacteroidetes ($t_1=2%$; $t_2=6%$), Proteobacteria ($t_1=10%$; $t_2=15%$) and Fusobacteria ($t_1=1%$; $t_2=8%$). The libraries also include 3 novel phylotypes for $t_1$ and 11 for $t_2$. Library $t_2$ differs from $t_1$ (P=.004); $t_1$ is a subset of the $t_2$ (P=.052). Periodontal pathogens, such as F. nucleatum, were more prevalent in $t_2$. CONCLUSION. The biofilm composition of the RPD metal clasps changed along time after RPD wearing. The RPD framework may act as a reservoir for potentially pathogenic bacteria and the RPD wearers may benefit from regular follow-up visits and strategies on prosthesis-related oral health instructions.

• Journal of the Korean Home Economics Association
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• v.40 no.8
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• pp.37-48
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• 2002

The purpose of this study was to survey Navajo's textiles of the transitional period(1868-1890) and to examine appearance background of those textiles. The two study questions were central to the project. 1) What were characteristics of eye-dazzler and pictorial in the transitional period? 2) How developed was the American trader's role? To perform the purpose, literatures on this subject were surveyed, investigation of textiles in Arizona State Museum and Historical Museum of Arizona were accomplished. The results of this study were as follows: 1. Eye-dazzler is called because of their small, serrate triangle and diamond patterns in intense, contrasting colors. Eye-dazzler mostly used Germantown yam and wedge-weave technique. Germantown was a plied yam colored with synthetic dyes. Wedge-weave technique used optical illusions and an undulating technique to create an effect of motion and rhythmic symmetry. 2. The Americans began to intern Navajos at Bosque Redondo, New Mexico in 1863. During their stay at Bosque Redondo, the Navajo came into greater contact with Rio Grande blankets. The influence of designs of these becomes increasingly important in the eye-dazzler. 3. Pictorial materials included rich new sources the railroad provided and living environment of animals, plants, hogans, neighbors, deities that interested the Navajo. Also, sandpainting textiles were a pictorial. Three types of textiles utilized: yei, yeibichai, and sandpainting tapestry. 4. The arrival of the railroad caused many changes for the lives and textiles of the Navajos. The railroad brought a new client into the Navajo, and the Navajos attempted new textiles with design-inspiring fresh materials to adjust taste of the eastern purchasers.

• Korean Institute of Interior Design Journal
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• v.21 no.6
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• pp.212-223
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• 2012

The "Eco-friendly", "Green" concepts was began around 1992 after the Rio Environmental Summit, and the need for sustainable development globally widespread. The green building certification system was began around 2000 and the concept of green building was started in the late 1990s. The green building, which welcomes a period of radical change, is for the survival of the Earth "climate change" and reducing energy consumption in building sector. In this architecture of eco-friendly concept, the green building is rapidly expanding and existing as a ecological environment preservation. Moreover, the realization of zero energy house is to mandate for new buildings in 2025. The aim of further eco-friendly is through the prior ecosystems to restore and product energy for the 9 Green Building model houses in this paper. Building in the concept of ecology is to show about change into 7R's from the 3R's. The "Reduce", "Reuse", "Recycle" consisting of "3R's" is correlated with the traditional to the present Green Building Design. U.S. NCARB (National Council of Architectural Registration Boards) change into the concept of 7R's as "Receive", "Restore", "Respect" and "Remember", added to "3R's". In this paper, the 9 Green Building model houses do not meet the criteria of 7R's. But, the Green Tomorrow of Samsung C & T Corporation meet the 6 criteria for 7R's. This company is most comfortable at low carbon Green Building model houses. Conclusionally, introduction of eco-friendly technologies and amenities for the health of human and natural community life is to advance eco-friendly construction and enhance brand value of housing. By the way, The problem of eco-friendly architecture is initial investment and maintenance. Therefore, eco-friendly architecture and government has to try solving of this difficulty.