• Journal of the Korean Wood Science and Technology
• /
• 제33권2호통권130호
• /
• pp.29-39
• /
• 2005

Formaldehyde emissions from wood-based panels bonded with pine and wattle tannin-based adhesives, urea-formaldehyde resin (UF), melamine-formaldehyde resin (MF), and co-polycondensed resin of urea-melamine-formaldehyde (UMF) were measured by the Japanese standard method using a desiccator (JIS A 1460) and the EN 120 (European Committee For Standardization, 1991) method using the perforator value. In formaldehyde emission, all particleboards made using the wattle tannin-based adhesive with three different hardeners, paraformaldehyde, hexamethylenetetramine, and tris(hydroxyl)nitromethan (TN), satisfied the requirements of grade $E_1$. But only those made using the pine tannin-based adhesive with the hexamine as hardener met the grade $E_1$ requirements. Hexamine was effective in reducing formaldehyde emission in tannin-based adhesives when used as the hardener. While the UF resin showed a desiccator value of $7.1mg/{\ell}$ and a perforator value of 12.1 mg/100 g, the MF resin exhibited a desiccator value of $0.6mg/{\ell}$ and a perforator value of 2.9 mg/100 g. According to the Japanese Industrial Standard and the European Standard, the formaldehyde emission level of the MDF panels made with UF resin in this study came under grade $E_2$. The formaldehyde emission level was dramatically reduced by the addition of MF resin. The desiccator and perforator methods produced proportionally equivalent results. Gas chromatography, a more sensitive and advanced method, was also used. The samples for gas chromatography were gathered during the experiment involving the perforator method. The formaldehyde contents measured by gas chromatography were directly proportional to the perforator values.

• 한국대기환경학회지
• /
• 제26권6호
• /
• pp.616-623
• /
• 2010

Recently, interests in indoor air quality (IAQ) have been increased; however, a number of researchers have mainly focused on anthropogenic volatile organic compounds (AVOC) emitted from building materials. Therefore, the properties of natural VOC (NVOC) and anthropogenic VOC (AVOC) emitted from wood-based panels was investigated in this work. VOCs emitted from these panels were sampled through Tenax TA/Cabotrap and analyzed by GC-MS and GC-FID. Comparisons were made concerning TVOC, NVOC, and composition ratios of NVOC. It was revealed that TVOC emission rates of midium density fiber (MDF) were the highest. Besides, it was found that emissions of NVOC from wood-based panels were much higher than those of anthropogenic AVOC except for plywood of Oceania timber. It was also observed that the composition ratio of NVOC emitted from plywood of Pinus radiata was the highest as 65% of TVOC. Major NVOC components were monoterpene compounds such as $\alpha$-pinene, $\beta$-pinene, d-limonene, camphene and $\alpha$-terpinene. It was concluded that the composition rates of VOCs emitted from building materials were clearly different according to the raw materials and manufacturing methods.

• 한국화재소방학회논문지
• /
• 제30권5호
• /
• pp.124-129
• /
• 2016

현행법상 현장방염 처리한 실내장식물은 관할 소방서에서 45도 연소시험을 통해 방염성능검사에 합격하여야 한다. 45도 연소시험법은 방염성능을 확인할 수 있는 가장 정확한 시험법이지만 시료 제출자가 부정시료를 제출하였을 경우에는 시험결과를 신뢰할 수 없다. 따라서 본 논문에서는 이러한 문제를 보완하기 위하여 X-선 형광분석기를 이용한 현장방염 검사방법을 제안하고자 한다. 총 10종의 방염도료를 합판 및 MDF에 처리하여 그 성분을 X-선 형광분석기로 분석한 결과 함유된 물질의 함량 차이로 인해 각 방염제마다 고유의 스펙트럼을 나타내고 있었으며, 측정기기로 손쉽게 각 물질별 함량(%)을 확인할 수 있었다. 따라서 제도적인 절차가 마련된다면 효율적인 현장방염검사방법으로 사용될 수 있을 것으로 기대된다.

• 한국화재소방학회논문지
• /
• 제34권4호
• /
• pp.13-21
• /
• 2020

본 연구에서는 건축내장용 합판류 목재를 대상으로 목재의 두께별 다양한 입사열유속에 따른 연소특성 측정 실험을 수행하였으며, 측정한 연소특성은 EHC, HRR peak 및 도달시간, MARHE, 인화온도이다. 실험에 사용된 목재 시편은 4.8~18 mm 두께, 목재 시편에 유입되는 입사열유속은 25, 35, 50 및 60 kW/㎡을 적용하였으며, 목재 시편의 종류는 MDF 2종, 파티클 보드, 일반 합판이다. 종합적인 비교를 통하여 연소특성별 각각의 목재에 해당하는 화재패턴을 분석하여 화재에 대한 위험성을 검토하였다. 파티클 보드의 경우 화재 위험성이 높게 나타났으며, 제시한 연소특성 정량화 결과는 복합 가연물의 화재하중 산정에 중요한 입력 요소로 기여될 수 있다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2003년도 춘계학술대회논문집
• /
• pp.802-807
• /
• 2003

International Convention Center Jeju(ICCJ) was planed and built for accommodating a variety of conventional and exhibitional activities. For a better flexibility of operation, almost all rooms in ICCJ are designed to be subdivided Into a couple of small rooms with installation of movable partition walls. Architectural and acoustical design should be deliberatively and cooperatively undertaken to cope with such a complex condition. Conference hall, the largest room in ICCJ, has a capacity of 5000 seats who:1 used as a whole. It could be divided into 3 halls, one with 2000 pre-installed seats on slanted floor, up/down removable stage and its settings above, and the other 2 flat rooms with no seats installed. A devided hall with pre-installed seats and stage is designed for a multi-use auditorium. Almost all surfaces except ceilings adjacent to the stage are sound absorptively treated, in regard to extensive use of sound reinforcement systems. Its reverberation time 1.65 sec without audience, which is roughly correspond to 1.50 sec with fully occupied audience. When there is a need for a larger room, all the partition wail Is removed and the hall could be used as a whole. Exhibition hall is located in the first floor of ICCJ. Absorption and softness are needed for the hat 1 because exhibition behavior has something noisy features. Perforated MDF panels with porous materials and air space in the back groundare adopted for the walls. There are one large, two medium, and several small convention rooms in ICJJ. The room are also acoustically designed for maximum flexibility with no defects soundwisely.

• The Korean Journal of Physiology
• /
• 제30권1호
• /
• pp.77-83
• /
• 1996

Platelet-activating factor(PAF) is a phospholipid mediator of pulmonary inflammation, and immunologic reaction. In this study, the role of PAF on tumor necrosis factor$(TNF_{-{\alpha}})$ production by rat alveolar macrophages(AM) was examined. When PAF $(10^{-12}{\sim}10{-16}\;M)$ alone was added to AM culture, $(TNF_{-{\alpha}})$ production was not significantly increased above the resting level. In contrast, the combined addition of PAF $(10^{-6}\;M)$ and muramyl dipeptide(MDP) $(1.0\;{\mu}g\ml)$ to AM cultures markedly enhanced $(TNF_{-{\alpha}})$ production with 8.2 fold increase compared with AM culture in resting state. This potentiative effect was 313% above the sum of the separate effects of PAF and MDP. To characterize MDP effects on $(TNF_{-{\alpha}})$ production, the dose-response of AM cultured with various concentrations of MDP was tested. High level of MDP $(10\;{\mu}g\ml)$ could not significantly enhance the potentiation effect on $(TNF_{-{\alpha}})$ production compared with AM cultures with low level of MDP $(0.1\;{\mu}g\ml)$, i.e. 112.5% vs 107.8%, respectively when $10^{-10}$ M of PAF was simultaneously added to the cell culture. These data support that the potentiation of TNF. g production in AM culture is mediated by PAF rather than MDf It was also evaluated whether the similar result was obtained in silica, respirable toxic particle-treated AM culture. $(TNF_{-{\alpha}})$ production was also significantly enhanced in the PAF $(10^{-6}\;M)$ and silica $(50\;{\mu}g\ml)$-added cell cultures with 4.7 fold above the value of silica alone-stimulated cells. These results indicate that PAF can potentiate $(TNF_{-{\alpha}})$ production by MDP-or silica- stimulated AM and suggest that PAF may play a potent role in lung inflammation and disease associated with microbe and occupational dust exposures.

• 정보처리학회논문지C
• /
• 제13C권7호
• /
• pp.881-888
• /
• 2006

기존 공동주택의 구내통신 선로설비 중의 댁내배선은 대부분 버스 배선 형태의 구조로 아웃렛의 위치에 따라 브릿지 탭(Bridged Tap)이 존재하게 된다. 이 브릿지 탭은 높은 주파수 대역을 사용하는 고속멀티미디어 통신의 특정 주파수에서 반사손실의 특성이 저하되어 선로의 감쇠가 급격히 증가하여 전송성능을 저하시키고 있어 이에 대한 분석이 필요하다. 본 논문에서는 기존 주거용 공동주택의 대표적인 아파트의 구내선로 구조 및 댁내 배선환경을 파악하고, 현업의 구내통신설비를 모델링하여 시험모형을 제작하여 VDSL 서비스 성능을 측정하였다. VDSL 서비스 시 브릿지 탭에 의해 성능에 미치는 영향을 분석하여, 기존 구내통신 선로의 문제점을 파악하고, 향후 초고속 멀티미디어 서비스 수용에 적합한 구내통신 선로의 품질개선 방안을 제시하였다.

• 펄프종이기술
• /
• 제44권4호
• /
• pp.1-7
• /
• 2012

The increase of OCC solid content after wet pressing will save drying energy greatly. We applied spacers, which used to increase draining rate and bulk in fiber furnishes, to increase the OCC solid contents. MDF fibers (fibers for making medium density fiberboard) and diatomaceous earth were used as spacers, and added 10% by weight to the OCC fiber furnish. Application of high wet pressing pressure to the mixed furnish of spacers and refined OCC did not deteriorate bulk and drainage rate, but their solid contents were increased to 0.5-1.5% without loss of compressive strength when compared to those of unrefined OCC, which is the furnish normally used for mill commercial practice. It is believed that the spacers caused the rate of solid content increase faster in the mixed furnish with OCC at high wet pressing pressure area than the unrefined OCC furnish did. Little amount of starch addition (0.5%) to the spacers helped to keep the strength properties.

• 대한환경공학회지
• /
• 제30권11호
• /
• pp.1102-1110
• /
• 2008

본 연구는 폐목재 발생원별 삼성분, 발열량, 그리고 중금속 및 Cl 함량을 분석하여 폐목재 특성을 평가함으로써 향후 폐목재 등급화를 위한 품질근거 기준을 마련하는데 필요한 기초자료를 제시하고자 하였다. 임목부산물, 생활계폐목재, 건설폐목재, 그리고 사업장폐목재의 4가지로 분류한 폐목재에서 수분함량은 대부분 5$\sim$10%를 나타내었으며, 이를 수분함량을 제외한 건조기준으로 환산하였을 때 가연분함량은 95% 이상이었고, 회분함량은 5% 이하를 나타내었다. 폐목재는 수분함량이 55%로 높았던 버섯재배폐목을 제외하고는 '건설폐기물의재활용촉진에관한법률'의 고형연료제품의 품질기준 중 발열량 기준(저위발열량 $\geq$ 3,500 kcal/kg)을 만족하였다. CCA (Cr, Cu, As)로 처리된 벤치목, 폐선박, 철도침목 등 방부목에서 CCA가 매우 높게 나타나 방부목의 사용과 관리, 폐기처분에 대한 엄격한 관리가 필요한 것으로 나타났다. Cl 함량은 목재 어(魚)상자에서만 약 1.3%로 가장 높게 나타났고 나머지 폐목재 및 재활용제품에서는 0.2% 이하의 낮은 값을 보였으나 고형연료제품의 염소함량 품질기준 (건조기준 2wt.%)을 모두 만족시켰다. 발생원별 폐목재를 유해물질 함유량을 기준으로 3등급화할 경우 대부분의 폐목재가 1등급에 해당하였으며, 합판류, MDF (medium density fiber), 표면도색된 전선드럼은 2등급에 해당하였다. 3등급에 해당하는 폐목재는 벤치목, 재활용공장목재분진, 폐선박과 철도침목으로 나타났다.

• 한국안광학회지
• /
• 제7권2호
• /
• pp.209-215
• /
• 2002

본 실험에서는 HWE 방법으로 성장시킨 SnSe 단결정 박막에 대한 특성을 조사하였다. 성장된 박막의 결정 구조와 격자 상수를 알아보기 위하여 X-ray diffraction(XRD)에 의한 회절 패턴을 측정하고, 단결정 박막의 결정성을 확인하기 위하여 double crystal X-ray diffraction(DCXRD)에 의한 회절 패턴을 측정하여, 원료부와 열벽부 그리고 기판의 온도 변화에 따른 반치폭을 알아보았다. Rutherford back scattering(RBS)을 측정하여 Sn과 Se의 조성비를 확인하고, 실험값과 이론값의 차이를 조사하였다. 박막의 표면 상태는 atomic force microscopy(AFM) 사진과 주사 전자 현미경(SEM) 사진으로 관찰하여 결정구조와 성장 온도와의 연관성을 조사하였다. 광학 상수는 Spectroscopic Ellipsometry(SE) 방법을 이용하여 단결정 박막의 굴절률(n), 유전상수(${\varepsilon}$), 반사율(R) 그리고 흡수 계수(${\alpha}$) 등 광학 상수를 측정했다.