Earticle

남해안 거제도 연안인 장목항에 인공부착판을 투입하여 주요한 부착성 저서동물의 가입양상을 조사한 결과, 3월에는 파래, 4월에는 지중해담치가, 5월에는 지중해담치와 유령멍게가 가입되었고, 6월에는 유령멍게와 다발이끼벌레류가, 8월에는 주걱따개비와 해변말미잘이 가입되었으며, 10월에는 석회관갯지렁이가 가입되었다. 월별로 투입된 부착판 1개월간 가입된 생물의 습중량은 5-6월에서 가장 많았다. 각 종들의 산란시기에 의해서 종 특유의 가입시기를 가지는 것으로 나타났다.

This study was conducted to investigate the recruitment pattern of sessile organisms on the artificial substrates of PVC in Jangmok Bay, Geoje Island, southern coast of Korea. Five PVC plates were submerged from March to October, 2007 at one month interval, and two plates were retrieved after one month. The dominant recruiters were a green algae, Entermorpha prolifera in March, Mytilus galloprovincialis in April, M. galloprovincialis and Styela plicata in May, S. plicata and Bugula sp. in June. During August, Balanus amphtrite and anthozoans were dominant recruiters, and a serpulid worm, Hydroides ezoensis in October. There was a clear specific recruiting period of sessile faunas depending on their reproduction cycles in a sheltered embayment like Jangmok Bay.

지식경제부 기술표준원이 수도관, 오 배수관, 토목용 하수관으로 광범위하게 사용되는 PVC(폴리염화비닐)관의 품질과 위생기준을 강화해 지난 해 7월 1일부터 납 안정제와 가소제 등의 사용을 금지하고, 위생성 및 장기내구성 등의 품질기준이 강화된 흰색 PVC관을 상 하수도관으로 사용토록 했으나 아직도 이를 제조하거나 시공하고 있어 주의를 촉구하고 나섰다. 이에 따라 PVC관을 수도관, 오 배수관으로 시공하고 있는 설비건설업계의 주의가 요망된다.

The polymeric membrane electrodes based on N,N'-bis-pyridin-2-ylmethylene-naphthalene-1,8-diamine as an ion carrier were prepared and tested for the copper-ion selective electrode. The membrane has a linear dynamic range between $10^{-6}$ and $10^{-2}$ M with a Nernstian slope of 29.6 mV per decade, and its detection limit was $10^{-5.62}$M. The potentiometric response is independent of the pH range of 3-5. The proposed electrode showed good selectivity and response for $Cu^{2+}$ over a wide variety of other metal ions in pH 4.0 buffer solutions.

The 3-[(2-furylmethylene)amino]-2-thioxo-1,3-thiazolidin-4-one (FTT) was used as an excellent ionophore in construction of a $Zn^{2+}$ PVC-based membrane sensor. The best performance was obtained with a membrane composition of 30% poly(vinyl chloride), 62% nitrobenzen (NB), 3% FTT and 5% sodium tetraphenyl borate (TBP). This membrane sensor shows very good selectivity and sensitivity towards $Zn^{2+}$ over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The membrane sensor revealed a great enhancement in selectivity coefficients for $Zn^{2+}$ ions, in comparison to the previously reported $Zn^{2+}$ membrane sensors. Theoretical studies also showed the selective interaction of TFF and $Zn^{2+}$ ions. The proposed membrane sensor exhibits a Nernstian behavior (with slope of 29.3 ${\pm}$ 0.3 mV per decade) over a wide concentration range (1.0 ${\times}$ $10^{-6}$-1.0 ${\times}$ $10^{-2}$) with a detection limit of 8.5 ${\times}$ $10^{-7}$ M (52 ng mL$^{-1}$). It shows relatively fast response time, in the whole concentration range ($\lt$ 20 s), and can be used for at least 10 weeks in a pH range of 3.0-7.0. The proposed membrane sensor was successfully used in direct determination of $Zn^{2+}$ ions in wastewater of industrial zinc electroplating companies, and also as an indicator electrode in titration with EDTA.

These days there are so many scheduling systems or softwares. But only few scheduling systems have succeeded in the market. In spite of powerful engine and functions, those systems have difficulties to be applied in real processes. In real processes, there are various constraints caused by physical or systematical environments of plants. Those constraints are too many to be handled in the system. This problem makes it difficult for the system to represent the details of processes. In order to resolve this problem, we have developed a specialized scheduling system for a target process. The system could be developed by the experts for target process and researchers for scheduling. In this study, a scheduling system for PVC process has been developed as an MILP (Mixed integer linear programming) model and coded in $Fortran^{TM}$. The scheduling system has been applied to two processes, which have different characteristics. Simulation results indicate that the profit of the target process can be increased by about 5% by implementing the scheduling system.

In a large-scale chemical plant, there are scheduling problems in inventory and packing process although production process is stabilized. The profit of the plant is restricted by these problems. In order to improve these problems, integrated scheduling model, which is concerned with whole processes from production to shipment, has been developed in this paper. In this model, decision variables are production sequence, silo allocation, amounts of bulk shipment and packing amounts. In case of a real plant, it is hard to solve by deterministic methods because there are too many decision variables to solve. In this paper, genetic algorithm is presented to solve a PVC process scheduling model within an hour with PCs.

A particle flow visualization, electrostatic charging measurement and separation of triboelectrically charged particles in the external electric field by a fluidized bed tribocharger are conducted for the removal of PVC particles from mixed waste plastics. The laboratory-scale triboelectrostatic separation system consists of the fluidized bed tribocharger, a separation chamber, a collection chamber and a controller. PVC and PET particles can be imparted negative and positive surface charges respectively due to the difference of triboelectric charging series between particles and particles in the fluidized bed tribocharger, and can be separated by passing them through an external electric field. To visualize these charged particles, He-Ne laser is used with cylindrical lenses to generate a sheet beam. In the charging measurement, the particle motion analysis system (PMAS), capable of determining particle velocity and diameter. is used to non-intrusively measure particle behavior in high strength electric field. The average charge-to-mass ratios of PVC and PET particles are $1.4\;and\;1.2{\mu}C/kg$, respectively. The highly concentrated PVC (91.9%) can be recovered with a yield of about 96.1% from the mixture of PVC and PET materials for a single-stage processing. The triboelectrostatic separation system using the fluidized tribocharger shows the potential to be an effective method for removing PVC from mixed plastics for waste plastic recycling.

NIRS(Near infrared spectroscopy) scanning from 1300nm to 2400nm was appl ied for the DEHP(di-(2 ethylhexyl)phthalate) in PVC(polyvinyl chloride_packing material. All samples were devided into calibration group and validation group. As a result of conduction the multiple regression analysis on the correlation between the NIR spectrum data and chemical assay value obtained by the Korea Food Sanitation Act. The validation model for measuring the DEHP content had R of 0.997, SEC of 0.132, SEP of 0.176 by MLR and R of 0.996, SEC of 0.142, SEP of 0.198 by PLS and the detection limit was 0.1%. The obtained results indicate that the NIR procedure can potentially be used as a nondestructive analysis method for the purpose of rapid and simple measurement of DEHP in PVC packing material.

Separation of PET and PVC is a key technology to achieve effective plastics recycling but no efficient and economically feasible method has been developed yet. The application of flotation was investigated by many researchers but the causes of the selectivity were not clarified. This paper described the adsorption mechanism of wetting agents onto plastics, using the agents which have various polarity and hydrocarbon chain length. It was found that (1) hydrophobic interaction played a predominant role for the adsorption, (2) anionic wetting agents could be adsorbed onto negatively charged plastics with the polar radicals oriented outer part of the plastics, then often depressed plastics more effectively than cationic agents, and (3) PET and PVC could be separated with dodecyamine hydrochloride and sodium dodecyl- sulfonate in the concentration ranges of 1.0$\times$10$^{[-10]}$ $^{6}$ -5.0$\times$10$^{[-10]}$ $^{5}$ and 2.0$\times$10$^{[-10]}$ $^{6}$ -1.0$\times$10$^{[-10]}$ $^{5}$ mo1/1, respectively.

Polyvinyl chloride (PVC) sheets were treated with corona discharge to produce peroxy radicals on the surfaces. The peroxy radicals formed on the PVC surfaces were subsequently used as initiators for the graft polymerization of acrylic acid or acrylamide in an aqueous solution. Introduction of acrylic acid and acrylamide on the PVC sheet could be confirmed by the observation of carbonyl and primary amine absorptions based on carboxylic acid and amide, respectively. The water contact angle$(90^\circ)$ of PVC sheet was constant, irrespective of time, while corona-treated and functional monomer-grafted PVCs were slowly increased with time, showing the rearrangement of surface polar groups in air condition. The water contact angle of PVC sheet$(90^\circ)$ was decreased by corona treatment$(78^\circ)$, and further decreased by the grafting of acrylic acid$(55^\circ)$ and acrylamide$(56^\circ)$ , indicating increased hydrophilicity of the modified surfaces. The half-life periods of surface voltage on acrylic acid- (62 sec) and acrylamide-grafted PVC (147sec) were significantly decreased when compared to those on PVC (3,115 sec) and corona-treated PVC (463sec). These results mean that acrylic acid- and acrylamide-grafted PVCs could be used as the antistatic sheets.

PVC핏치의 제조 조건에 따른 물성 변화 및 산화 안정화에 영향을 미치는 공정 변수를 연구하기 위하여 열중량 분석을 하였다. 산소 분위기를 사용하여 안정화온도, 승온속도 및 가스의 유량을 변화시켜 조사하였다. 안정화 온도가 높아짐에 따라 무게증가를 나타내는 시간구간이 짧아지고 결합되는 산소의 양은 감소하는 경향을 나타내며, 29$0^{\circ}C$정도로 안정화 온도가 높은 경우에는 결합되는 산소의양이 최대점에 도달한 후 다시 감소하는 경향을 나타냈다. 승온속도가 빨라짐에 따라 결합되는 산소의양은 감소하는 경향을 나타내었으나, 가스의 유량은 본 연구에서 설정한 범위 내에서는 영향이 관찰되지 않았다. 핏치 입자 직경이 커짐에 따라 최대 무게증가 값은 감소하고 최대 무게증가를 나타내는 온도는 증가함을 알았다. 그리고, 안정화에 의한 무게증가가 클수록 PVC핏치의 탄소수율은 감소하는 경향이 나타났다.

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.

19년동안 건축물 배관자재만을 전문으로 생산해온 평화플라스틱공업(주)은 「원터치 이음관 」 「스펜 파이프 」등 신제품을 개발해 건축물에서 가장 문제가 되고 있는 누수문제를 해결, 파이프업계에서 두각을 나타내고 있다.

The glass transition temperature, dynamic shear moduli, and bulk viscosities of PVC, filled with nickel particles, were investigated. The glass temperature of the composite increased with increasing filler concentration. The data were interpreted by assuming that the interaction between filler particles and the polymer matrix reduces molecular mobility and flexibility of the polymer chains in the vicinity of the interfaces. The relative modulus for the PVC/Ni composite system followed the Kerner equation. The relative viscosities were strongly temperature dependent and did not agree with the conventional viscosity predictions for suspensions. It is suggested that the filler has a twofold effect on the viscosity of the composite materials; one is due to its mechanical presence and the other is due to modification of part of the polymer matrix caused by interaction. This phenomenon is approximately bounded by Kerner's predictions for suspensions.

Objective: This study investigated the anti-inflammatory effects of Poncirus trifoliata Rafinesque and Viola mandshurica Baker Complex (PVC) on tumor necrosis factor-alpha (TNF-α)-induced inflammation in human umbilical vein endothelial cells (HUVECs). Methods: HUVECs were pretreated with PVC and subsequently stimulated with TNF-α. The mRNA and protein expression levels of IL-6, iNOS, eNOS, KLF2, IL-8, MCP-1, ICAM-1, and VCAM-1 were quantitatively analyzed. Additionally, phosphorylation levels of ERK, JNK, and p38 were assessed. Results: PVC significantly reduced the mRNA and protein expression levels of IL-6, iNOS, MCP-1, ICAM-1, and VCAM-1 compared to the controls while increasing the expression of eNOS and KLF2. No significant effect was observed on IL-8 expression. Furthermore, PVC markedly decreased the phosphorylation levels of ERK, JNK, and p38 relative to the controls. Conclusions: PVC can protect vascular endothelial cells from inflammatory damage, which may prevent cardiovascular disease by inhibiting vascular inflammation associated with atherosclerosis.

A triboelectric nanogenerator (TENG) is a device that converts mechanical energy into electrical energy, and has been considered as a substitute for continuous power supply due to its high performance, simple structure and eco-friendliness. Recently, it is important to develop a TENG using a non-toxic material in order to use it as a power source for wearable, attachable, and body-embeddable electronics. Here, we developed a human friendly TENG using polyvinyl chloride (PVC) gel containing acetyl tributyl citrate (ATBC), a non-toxic plasticizer. PVC gels were fabricated using various ratios of PVC and ATBC, and optimized by investigating dielectric properties, surface potential, output performance, and durability. The PVC gel based TENG generates output signals of 73 V and 4.3 μA, i.e., a 5-fold enhancement in the output power compared to pristine PVC-based TENG. In addition, the PVC gel can be stretched over 500% of strain. This study is expected to be helpful in the future development of non-toxic wearable TENG.

본 연구는 세균에 대한 항균효과와 난연 특성을 갖는 신소재의 개발이 목표이다. 제올라이트의 기공에 은과 아연을 포함한 무기항균제(inorganic bacteriocide, IB)와 친환경 무기계 난연제인 aluminum trihydroxide(ATH)를 함유한 PVC 복합소재인 PVC/IB/ATH를 제조하였다. 두 종류의 세균으로 탁도 분석법, 진탕 배양법, drop-test, 이중 염색법을 사용하여 PVC/IB/ATH 복합소재의 항균효과 실험결과 99%의 항균효과를 확인하였다. 또한 한계산소농도지수와 열중량 분석으로 PVC/IB/ATH 복합소재의 난연 특성을 확인한 바, ATH와 무기항균제의 알루미늄 성분에 의존적으로 증가하였다. 또한 PVC/IB/ATH 복합소재의 열적 특성은 소폭 증가하였다. 결론적으로, PVC/IB/ATH의 응용은 의료 산업, 항균 시스템 그리고 난연 물질과 같은 다양한 분야에 이용될 것으로 기대한다.

<P>The aim of this study is to develop new materials with antimicrobial effect and flame-retardant properties. PVC/IB/ATH, a PVC composite material containing inorganic bacteriocide (IB) with silver and zinc in the zeolite pores, and aluminum trihydroxide (ATH), an environmentally friendly inorganic flame-retardant, was prepared. The antimicrobial effect of PVC/TB/ATH composite material was confirmed to be 99% as a result of turbidity analysis, shaking culture, drop-test, and double staining test using two kinds of bacteria. The flame-retardant properties of PVC/IB/ATH composites were investigated by limiting oxygen concentration index and thermogravimetric analysis, and they were increased depending on the aluminum content of ATH and IB agent. Also, the thermal properties of PVC/IB/ATH composites were slightly increased. In conclusion, the application of PVC/IB/ATH is expected in various fields such as medical industry, antibacterial system and flame-retardant materials.</P>

본 연구는 세균에 대한 항균효과와 난연 특성을 갖는 신소재의 개발이 목표이다. 제올라이트의 기공에 은과 아연을 포함한 무기항균제(inorganic bacteriocide, IB)와 친환경 무기계 난연제인 aluminum trihydroxide(ATH)를 함유한 PVC 복합소재인 PVC/IB/ATH를 제조하였다. 두 종류의 세균으로 탁도 분석법, 진탕 배양법, drop-test, 이중 염색법을 사용하여 PVC/IB/ATH 복합소재의 항균효과 실험결과 99%의 항균효과를 확인하였다. 또한 한계산소농도지수와 열중량 분석으로 PVC/IB/ATH 복합소재의 난연 특성을 확인한 바, ATH와 무기항균제의 알루미늄 성분에 의존적으로 증가하였다. 또한 PVC/IB/ATH 복합소재의 열적 특성은 소폭 증가하였다. 결론적으로, PVC/IB/ATH의 응용은 의료 산업, 항균 시스템 그리고 난연 물질과 같은 다양한 분야에 이용될 것으로 기대한다.

The aim of this study is to develop new materials with antimicrobial effect and flame-retardant properties. PVC/IB/ATH, a PVC composite material containing inorganic bacteriocide (IB) with silver and zinc in the zeolite pores, and aluminum trihydroxide (ATH), an environmentally friendly inorganic flame-retardant, was prepared. The antimicrobial effect of PVC/IB/ATH composite material was confirmed to be 99% as a result of turbidity analysis, shaking culture, drop-test, and double staining test using two kinds of bacteria. The flame-retardant properties of PVC/IB/ATH composites were investigated by limiting oxygen concentration index and thermogravimetric analysis, and they were increased depending on the aluminum content of ATH and IB agent. Also, the thermal properties of PVC/IB/ATH composites were slightly increased. In conclusion, the application of PVC/IB/ATH is expected in various fields such as medical industry, antibacterial system and flame-retardant materials.

A potentiometric sensor based on the Schiff base $(N^2E,N^{2'}E)-N^2,N^{2'}$-bis(thiophen-2-ylmethylene)-1,1'-binaphthl-2,2'-diamine has been synthesized and explored as an ionophore PVC-based membrane sensor selective for the silver ($Ag^+$) ion. Potentiometric investigations indicate a high affinity of this receptor for the silver ion. Seven membranes have been fabricated with different compositions, with the best performance shown by the membrane with an ionophore composition (w/w) of: 1.0 mg, PVC: 33.0 mg, DOA: 66.0 mg in 1.0 mL THF. The sensor worked well within a wide concentration range of $1.0{\times}10^{-2}$ to $1.0{\times}10^{-7}$ M, at pH 5, at room temperature (slope 57.4 mV/dec.), and with a rapid response time of 9 s; the sensor also showed good selectivity towards the silver ion over a huge number of interfering cations, with the highest selectivity coefficient for $Hg^{2+}$ at -3.7. Thus far, the best lower detection limit was $4.0{\times}10^{-8}$ M.