• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.7
• /
• pp.4977-4983
• /
• 2015

The full depth excavation induces couple of technical and social problems like increase of construction cost and time for excavation and backfill, increase of public complains and delay of traffic, and so force. In order to overcome these problems, lots of laboratory tests were carried out for sewer pipeline of maintenance materials with trenchless methods. The testing materials are PVC strip and then the lab tests were followed by Korean Standard. We will treat the structure safety and pipe integrity of PVC profile more excellent than the profile have application to SPR. There is no side-effect to process and to satisfy the criteria of tensile strength, impact strength and softening temperature. The profile with resin adhesive showed no leakage of water at specific pressure.

• Elastomers and Composites
• /
• v.47 no.2
• /
• pp.129-140
• /
• 2012

The objective of this study was to estimate the practical recycling rate of plastic products, so that the study was conducted to build material flow diagram for PVC profile. For this objective, product generation, waste generation and recycling status were investigated. Using collected and analyzed status data, analysis of material flow by product and building material flow diagram were conducted. As result of estimating the recycling rate by product, The sum of domestic demand was 525,448 ton and waste generation was 105,853ton in PVC flooring and profile. The sum of generation of recycling product and raw material was investigated to be 76,004ton(14.46%), which is higher compared to recycling obligation(8.5%) in 2009. To build the material flow diagram in the years(5~20years) ahead, prediction of future demand was based on the assumption that there will be no difference in annual generation of current and future. As the recycling rate of flooring and profile increases, it is estimated to reach 20% in 2013 according to the material flow diagram.

• Journal of Korean Society of Water and Wastewater
• /
• v.20 no.3
• /
• pp.431-441
• /
• 2006

This study investigated the physiological characteristics of biofilm microorganisms formed onto the different drinking water distribution pipe surfaces. The simulated drinking water distribution pipe system which had several PVC, STS 304, and GS coupons was operated at flow velocity of 0.08 m/sec (Re 1,950) and 0.28 m/sec (Re 7,300), respectively. At velocity of 0.08 m/sec, the number of viable heterotrophic bacteria in the biofilm over the 3 months of operation averaged $3.3{\times}10^4$, $8.7{\times}10^4$, and $7.2{\times}10^3CFU/cm^2$ for PVC, STS, and GS surfaces, respectively. The number of attached heterotrophic bacteria averaged $1.4{\times}10^3$, $5.6{\times}10^2$, and $6.5{\times}10^2CFU/cm^2$ on PVC, STS, and GS surfaces at the system with relatively high flow velocity of 0.28m/sec. The changes of physiological profile of biofilm-forming microorganisms were characterized by community-level assay that utilized the Biolog GN microplates. Biofilms that formed on different pipe surfaces displayed distinctive patterns of community-level physiological profile (CLPP), which reflected the metabolic preference for different carbon sources and/or the utilization of these carbon sources to varying degrees. The CLPP patterns have shown that the metabolic potential of a biofilm community was different depending on the pipe material. The effect of the pipe material was also characterized differently by operation condition such as flow rate. At flow velocity of 0.08 m/sec, the metabolic potential of biofilm microorganisms on GS surface showed lower levels than PVC and STS biofilms. For biofilms on pipe material surfaces exposed to water flowing at 0.28 m/sec, the metabolic potential was in order of PVC>GS>STS. Generally, the levels of the bacterial biofilm's metabolic potentials were shown to be notably higher on pipe surfaces exposed to water at 0.08 m/sec when compared to those on pipe surfaces exposed to water at 0.28 m/sec.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2001.11a
• /
• pp.115-120
• /
• 2001

본 논문에서는 비닐 튜브의 결함검사에 이용하기 위한 이진화 임계치의 자동 결정방법과 패턴매칭에 이용되는 패턴 모델의 자동 친정방법에 대하여 기술한다. 256 Gray 영상을 받아 들여 이진화 임계치를 결성하기 위해서, 휘도치 분포 곡선에서 2개의 극대값을 찾고, 두 극대 위치의 중간위치를 이진화 임계치로 결정하는 방법을 이용하였다. 그리고 패턴 모델을 생성하기 위하여는 수직, 수평 방향의 누적함(Profile)을 이용하였다. 이 방법은 인쇄물 검사 시스템뿐 아니라 비슷한 휘도치 분포를 같는 반도체 자동 검사 시스템을 비롯한 일반적인 건사 시스템에 적용이 가능하다.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.16 no.3
• /
• pp.219-224
• /
• 1996

Silage comkv, suwwn 19). sorghum $\times$ sudangrass(p. 988) and winter ryeNaton) were cultivated on imperfectly drained paddy field under two different draining methods, subsurface darinage by PVC pipes and open ditsched surface drainage. The crops were harvested at the stage of hard dough for corn and soft dough for wrghum and rye. The soil physical properties. soil colors. soil structure and soil wetness were improved in the subsurface drainage. Gravitational water table occured depth in 110 cm(dry season)~75cm(rain season). In soil profile description, yellowish brown with yellowish red mottles and well developed granular structure were found in the surface A horizon. The portion of solid phase in subsoils(B horizon) was reduced from 48.6%(undrained) to 43.7 %. A blocky structure with dark gray to gray were described in the open ditsched surface drainage. Severe wet depression of the crops was observed due to it's higher moisture contents, where the gravitational water occured depth in 25~37cm during the rainy season. The chemical properties of paddy soils were less affected by drainage methods. The concentration of available phosphate. organic matter and exchangeable K, Ca and Mg were decreased in the subsurface drained soils. The annual dry matter yields of com-rye cropping were 17.8 ton in the undrained, 21.6 ton in the open ditsch drainage and 35.9 ton/ha in the subsurface drainage.

• Journal of Korean Society of Water and Wastewater
• /
• v.26 no.6
• /
• pp.767-777
• /
• 2012

Annular Biofilm Reactor (ABR) equipped with coupons of three different pipe materials (STS 304, PVC, PE) was used to generate drinking water biofilm samples. The level of assimilable organic carbon (AOC) during the sample generation period was $37.3{\mu}g/L$, and this level did not seem to be low enough to limit the formation of biofilm in this study. Terminal-restriction fragment length polymorphism (T-RFLP) analyses determined T-RF profile as early as 3 h of exposure on PVC coupons. Average surface roughness ($R_a$) measured by atomic force microscopic analyses was 125.7 nm for PVC, and this value was higher than for STS (71.6 nm) and PE (74.0 nm). However, biofilm formation was faster on STS (6 h) than on PE (12 h), which indicated that surface roughness might not be the only factor that controlled the initiation of biofilm development. Upon detection of the T-RF peaks, richness (S) and diversity indices such as Shannon (H) and Simpson (1/D) demonstrated a rather slow increase until 48 h followed by rapid increase regardless of the pipe materials. Differences of microbial community structures among the biofilm samples were determined based on the cluster analysis using Jaccard coefficients (Sj). Biofilm communities could be divided into two distinct groups according to the exposure time regardless of the pipe materials. First group contained a young (< 48 h) biofilm samples (10 out of 11) but second group contained a mature (${\geq}$ 48 h) samples (11 out of 14). Results suggested that, due to the complexity of biofilm, the targeting of the first group of cluster was crucial for optimizing the management of drinking water distribution systems and controlling microbial growth.

• Journal of Korean Port Research
• /
• v.8 no.1
• /
• pp.17-22
• /
• 1994

The wave interaction with flexible membrane such as PVC and fabrics is studied to prove its applicability to portable breakwaters. To obtain the wave exciting force acting on flexible membrane, eigen-function expansion method is employed. The effect of flexible is involved in body boundary condition in which x-directional displacement of membrane is obtained by solving the linear membrane equation. Displacement of membrane is assumed to be small compared to wavelength, therefore the tensile force of membrane remains constant. As the numerical examples, transmission and reflection coefficients according to the change of tensile forces are investigated. The hydrodynamic force on membrane, the dynamic tension in the mooring lines and the vertical displacement profile of membrane are also calculated. It is suggested that the flexible membrane can be used to engineering material for the future coastal/ocean applications.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.2
• /
• pp.115-123
• /
• 2011

To investigate the effects of pipe materials on biofilm accumulation and water quality, an annular reactor with the sample coupons of four pipe materials (steel, copper, stainless steel, and polyvinyl chloride) was operated under hydraulic conditions similar to a real plumbing system for 15 months. The bacterial concentrations were substantially increased in the steel and copper reactors with progression of corrosion, whereas those in stainless steel (STS) and polyvinyl chloride (PVC) reactors were affected mainly by water temperature. The heterotrophic plate count (HPC) of biofilms was about 100 times higher on steel pipe than other pipes throughout the experiment, with the STS pipe showing the lowest bacterial number at the end of the operation. Analysis of the 16S rDNA sequences of 176 cultivated isolates revealed that 66.5% was Proteobacteria and the others included unclassified bacteria, Actinobacteria, and Bacilli. Regardless of the pipe materials, Sphingomonas was the predominant species in all biofilms. PCR-DGGE analysis showed that steel pipe exhibited the highest bacterial diversity among the metallic pipes, and the DGGE profile of biofilm on PVC showed three additional bands not detected from the profiles of the metallic materials. Environmental scanning electron microscopy showed that corrosion level and biofilm accumulation were the least in the STS coupon. These results suggest that the STS pipe is the best material for plumbing systems in terms of the microbiological aspects of water quality.

• Journal of the Korean Geotechnical Society
• /
• v.15 no.6
• /
• pp.239-249
• /
• 1999

In this study, experimental work has been carried out to investigate the effect of lateral soil movement on passive piles. This paper consists mainly of two parts: the first, performance of a series of laboratory experiments on a single pile and one-row pile groups, and the second, comparison between the measured and the predicted results. In the laboratory experiments, a quadrilateral soil movement profile was imposed on model piles embedded in both sandy soils and weathered soils. The maximum bending moment and pile deflection induced in passive piles were found to be highly dependent on pile stiffness, pile spacing, relative densities and pile head fixity condition. It was shown that the group effect might either increase or decrease the maximum bending moment and pile deflection, depending on the aforementioned influence factors. Based on the results obtained, a spacing-to-diameter ratio of 7.0 seems to be large enough to eliminate the group effect, and a pile in such a case behaves essentially the same as a single pile.

• Development and Reproduction
• /
• v.24 no.3
• /
• pp.197-205
• /
• 2020

Diabetes mellitus is a common heterogeneous metabolic disorder, characterized by deposition of extracellular matrix, oxidative stress, and vascular dysfunction, thereby leading to gradual loss of function in multiple organs. However, little attention has been paid to gene expression changes in the lung under hyperglycemic conditions. In this study, we found that diabetes inuced histological changes in the lung of streptozotocin-induced diabetic mice. Global gene expression profiling revealed a set of genes that are up- and down-regulated in the lung of diabetic mice. Among these, expression of Amigo2, Adrb2, and Zbtb16 were confirmed at the transcript level to correlate significantly with hyperglycemia in the lung. We further evaluated the effect of human umbilical cord-derived perivascular stem cells (PVCs) on these gene expression in the lung of diabetic mice. Our results show that administration of PVC-conditioned medium significantly suppressed Amig2, Adrb2, and Zbtb16 upregulation in these mice, suggesting that these genes may be useful indicators of lung injury during hyperglycemia. Furthermore, PVCs offer a promising alternative cell therapy for treating diabetic complications via regulation of gene expression.