Earticle

제품 표면에 코팅을 하는 것은 원자재나 디자인을 개선하는 것보다 훨씬 효과적인 결과를 가져온다. 제품에 코팅을 적용하면 성능과 신뢰성이 향상되어 수명이 증가되고, 소형 경량화가 가능해진다. 자동차 엔진과 그 외의 부품에 적용할 경우 에너지 절감 효과가 있고 친환경 요구에 부응할 수 있어 그 효과가 크다. 시스템의 잠재된 성능은 특정 목적에 따라 맞춤된 PVD/PACVD 코팅에 의해서 향상 될 수 있고, 실제로도 많은 경우 PVD/PACVD 코팅만이 새로운 설계 솔루션을 실현 가능하게 해준다.

Objective: This case report examines the treatment response of a traditional herbal medicine for palpitations presumed to be associated with premature ventricular contraction (PVC). Case presentation: A 29-year-old male diagnosed with PVC attributed to a weak blood and heart fire pattern underwent 30-day outpatient treatment using modified Chungshimbohyeol-tang (Qīngxīn Bǔxuè Tāng). Palpitations were monitored weekly, daily, and by duration. Over 30 days, the palpitations decreased from 5 days/week, 1-2 times/day, and 20-60 minutes/palpitation to 1 day/week, 1-2 times/day, lasting only seconds. Two months post-treatment, the symptoms had fully resolved, and no adverse effects were reported during treatment or follow-up. Conclusion: This study suggests that palpitations caused by PVC may be effectively managed with traditional herbal medicine, particularly in patients who avoid treatment or are unsuitable for conventional treatments. Further studies on long-term outcomes and safety are necessary.

In this study, we experimented a deterioration characteristics by series arcing with 600V polyvinyl chloride insulation wire and analyzed the glowing/growing process of copper oxide, waveforms of contact voltage, current, power dissipation and carbonized patterns of insulation. We know that how glowing contacts and surface arcing can decompose PVC insulation and that it is possible for the subsequent series arc to ignite, and burn insulation. We expect that these results are useful for advancing the state-of-the-art in fire protection by Providing a better understanding of how electrical fires can initiate.

PVC 와 Polystyren 과 같은 고분자가 자외선에 노출될 때 이들 표면을 보호하고, 물성을 유지하기 위해서 자외선 경화 도료를 도장하지만, PVC 는 epoxy acrylate 에 대해서, 그리고 Polystyren 은 대부분의 UV도료에 부착력이 약하므로, 반응희석제의 조성을 변화시키거나, 다관능기 acrylate를 표면에 photografting 시키거나, 표면을 광화학적으로 활성화시켜 부착력을 향상시킴을 목적으로 하였다. 미리 침투시킨 광개시제에 의한 grafting이나 표면 활성화로 부착력은 현저히 증가하였고, 각 희석제에 있어 Tripropylene glycol diacrylate는 유연성 향상과 부착력 증가를 가져오나, 황변 현상과 표면 산화에 의한 경화 밀도의 증가로 grafting을 제외한 다른 도장 방법은 시간이 지남에 따라 도막의 부착력이 감소하였다. 여기에 비해 Trimethylol propane triacrylate 는 원래 다관능기에 의해 높은 경화 밀도를 가지고 이에 따른 단단한 도막 때문에 부착력에 문제가 있으나, 두가지 도장법에서는 오히려 다관능기에 의한 화학 결합으로 부착력이 향상되었다. 그리고, 고분자 표면의 표면 에너지를 활성화를 통해 증가시킴으로 해서 UV 도료의 상용성 문제를 grafting 과 표면 활성화를 통해 해결해 도료 배합의 다양화와 기능화를 가져올 것이 기대된다.

Ultraviolet curable coatings are often used to protect the surface of polymer materials exposed to the ultraviolet radiation. However, the adhesion of epoxy acrylate on poly(vinyl chloride) and the UV curable coating on polystyren are poor. The objective of this work was to improve the adhesion of coating according to various formulations of the reactive diluents and finishing methods using the photografting of multifunctional acrylate and the surface activation on polymer surface impregnated a phtoinitiator. The addition of Tripropylene glycole diacrlate in the formulation of coating results in the improvement of adhesion of coating due to the flexibility. But the increase of the crosslinking density which results from the oxidation of surface during the exposure of UV radiation caused the loss of adhesion of coating exept the photografting method. In the trimethylolpropane triacrylate the improvement of adhesion are considerable due to the chemical bond between multifundtional acrylate and surface. From this work we expect to achieve the varity and functionality in the formulation of coating according to the photografting and surface activating of polymer.

꽃노랑총채벌레(Frankliniella occidentalis (WFT, western flower thrips))는 시설국화의 중요한 해충이다. 황색끈끈이 트랩에 유살된 꽃노랑총채벌레는 트랩식물의 위치에서 가장 높았고 트랩식물로부터 15 m와 20 m 떨어진 지점에서 가장 낮았다. 토양재배국화의 정식 30일 후에 투입한 트랩식물의 꽃노랑총채벌레 유인수에 있어 트랩식물이 투입된 0 m 지점이 트랩식물로부터 떨어진 5 m와 10 m 지점에서 보다 4.4~7.7배 더 많이 채집되었고(resident WFT) 정식과 동시에 투입한 트랩식물의 꽃노랑총채벌레 유인수는 5.7~9.4배 더 많았다(dispersing WFT). 재배국화의 꽃봉우리가 형성되면서 트랩식물이 위치한 곳과 위치하지 않는 곳에서 꽃노랑총채벌레의 밀도에는 분명한 차이가 없었다. 트랩식물과 천적을 동시 활용한 시험구는 농약살포구 보다 꽃노랑총채벌레의 밀도가 더 낮았고, 트랩식물에 농약을 사용한 시험구는 트랩식물의 위치에서만 꽃노랑총채벌레가 방제되었을 뿐 5 m와 10 m에서는 밀도가 증가하였다. 따라서, 국화 재배를 위한 정식과 동시에 꽃노랑총채벌레 방제를 위하여 트랩식물로 황색개화국화를 천적과 같이 이용한다면 효과적일 것이다.

F. occidentalis (WFT, western flower thrips) is a major pest in artificial chrysanthemum houses. Nnumber of WFT attracted to yellow sticky trap was highest at trap plant and lowest at 15 and 20m places away from trap plant. Number of WFT attracted to yellow stick trap when trap plant was placed in chrysanthemum house 30 days after planting (resident WFT) was 4.4~7.7 times more than at 5 and 10 m places away from trap plant and when trap plant was placed in chrysanthemum house immediately after planting (resident WFT) was 5.7~9.4 times more at 5 and 10 m places away from trap plant. Number of WFT between the place trap plant located and unlocated was undifferent when cultured chrysanthemum formed flower. In case of the plot that trap plant and natural enemy was used simultaneously, number of WFT was highter then chemicals plot. In case of the plot that trap plant and chamicals (chemicals was sprayed on trap plant only) WFT was controlled in trap plant place only but density of WFT on 5m and 10m places away from trap plant was increased. Therefore, WFT could be controlled effectively by use of trap plant (flowering yellow chrysanthemum) and natural enemy simultaneously.

The accuracy and precision of a modified method of NIOSH Method 7600 and EPA method 218.6 was determined for analyzing hexavalent chromium, Cr(VI), collected on PVC filter from workplace air. The method was designed to extract from Cr(VI) on PVC filter with a alkali solution, 2% NaOH/3% $Na_2CO_3$, and to analyze it using ion chromatography/visible absorbance detection(IC/VAD). The results and conclusion are as the following. 1. The peak of Cr(VI) was separated sharply on chromatogram and was linearly related with Cr(VI) concentration in sloution. The correlation coefficient was 0.9999 in a calibration curve. The limit of detection was 0.25 $0.25{\mu}g/sample$. 2. The accuracy(% recovery) was 93.3% in a set of sample($9-50{\mu}g$) stored for a day, and 100.1%($10-60{\mu}g$) in another set of samples stored for 2 hours. It is assumed that the difference in recovery by storage time was due to reduction of Cr(VI) to Cr(III). 3. The precision(coefficient of variation, CV) of the method was 0.015 in spiked samples with Cr(VI) standard solution, and 0.010 in spiked samples with plating solution from a chrome electroplating factory. The overall CV in all types of samples was 0.0013. 4. The Cr(VI) was stable in 2% NaOH/3% $Na_2CO_3$ at least for 10 hours. In conclusion, the IC/VAD method is appropriate for determining low-level Cr(VI) in workplace air containing various interferences.