• 임산에너지
• /
• 제20권1호
• /
• pp.35-41
• /
• 2001

리그닌 모델화합물 Ⅰ-Ⅳ의 시료를 315℃에서 열분해 시킨 결과, 리그닌 모델호합물 Ⅰ, Ⅱ의 열분해에서는 guaiacol이 0.47mol, DMP가 0.57mol로, DMAP는 0.12와 0.23mol로 각각 생성되었으며, 리그닌 모델화합물 Ⅲ, Ⅳ의 열분해에서는 guaiacol의 생성이 0.26mol, DMP가 0.30mol로 TMAP는 0.09mol 과 0.15mol이 각각 생성되었다. 리그닌 모델화합물 열분해 메커니즘으로서는 우선 탈수되고, 이어서 β-O-4 결합이 개열되어 guaiacol, DMP, DMAP와 TMAP가 생성되는 것을 알 수 있었다.

• 공업화학
• /
• 제26권2호
• /
• pp.128-131
• /
• 2015

친환경적 조건에서의 니트릴의 수화 반응은 아미드를 생산하기 위한 가장 경제적이고 매력적인 방법이다. 고체 금속 산화물과 지지체를 이용한 전이 금속 촉매 시스템은 이러한 니트릴 수화 반응을 보다 향상시키기 위한 의미 있는 연구로써 수행되어져 왔다. 이들 촉매들의 중요한 특징은 방향족, 지방족, 이종 원자형, 지방족 고리형 등의 니트릴들을 포함하는 넓은 범위의 다양한 기질들에 적용된다는 것이다. 또한 이들은 높은 촉매적 활성을 유지하면서 여러 번의 재사용성이 가능하고 반응 후 그 혼합물로부터 분리가 용이하다는 장점들을 갖는다. 이 리뷰를 통하여 니트릴 수화반응을 통한 아미드 합성에 적용되는 금속 산화물과 지지체를 가진 금속 촉매들에 대해 알아본다.

• 대한약침학회지
• /
• 제8권3호
• /
• pp.71-77
• /
• 2005

Objective : Literary investigation of existing data was conducted to verify effects of Moschus and its herbal acupuncture, and determine quality management through component analysis. Results : Following results were obtained through literary investigation. 1. Deer musk (Moschus) is dried navel gland secretions of the adult male musk deer. 2. Moschus is known to be effective for treating various febrile diseases, to revive senses, heart and abdominal pain, complications from cerebral hemorrhage, angina, and others. 3. Single dosage of Moschus is between $0.03{\sim}0.1g$ and should not exceed 1g. Normally taken as powder or pill and may be used externally. 4. Moschus also has protective effects for the liver cells, and experiments revealed possible efficacies for hyperlipidemia, brain damage, hypertension, and etc. 5. For herbal acupuncture usage, Fel Ursi, Bezoar Bovis, and Moschus are used as a mixture (BUM), and it's known to be effective for protecting the liver and treating arthritis. 6. For component analysis of Moschus, aromatic matter 'muscone' should be used as a standard matter.

• 멤브레인
• /
• 제17권1호
• /
• pp.1-13
• /
• 2007

분리막을 이용한 투과증발공정은 에너지 소모가 적고 설치비와 운영비면에서 우수한 효과를 볼 수 있기 때문에 증류공정을 대신할 수 있는 공정으로 주목받고 있다. 특히 석유화학공정은 공정 중에 에너지 소모가 크고, 많은 화합물들이 공비혼합물을 이루고, 새로운 공정을 설치하기 위해서는 작은 공간을 필요로 하기 때문에 투과증발공정은 증류공정을 대체할 수 있는 매우 유력한 후보이다. 벤젠/시클로헥산을 포함하는 방향족 화합물의 분리, 올레핀/파라핀 분리, 자일렌 이성질체의 분리, 반응성 단량체의 회수, 가솔린으로부터 황 화합물의 제거 등에 투과증발공정을 응용하는 많은 연구가 이루어졌으며, 상용화가 되고 있다.

• 한국식품위생안전성학회지
• /
• 제23권1호
• /
• pp.26-30
• /
• 2008

다환방향족탄화수소는 환경오염이나 식품의 제조공정 과정 중에 생성될 수 있으며, 홍삼은 수증기로 찌고 건조하여 만들어진다. 시료를 핵산으로 추출한 후 물로 세척하고 후로리실 SPE 카트리지로 정제한 후 고속액체크로마토그래피/형광검출기로 분석하였다. 이동상으로는 아세토니트릴과 물의 혼합용액(8:2)을 사용하였으며 형광검출기의 여기파장은 294 nm이었고 형광파장은 404 nm이었다. 평균 회수율은 105%이었으며, 상대표준편차는 0.5이었다. 대상 식품인 홍삼음료 중 벤조피렌은 검출되지 않았다.

• Journal of Microbiology and Biotechnology
• /
• 제16권11호
• /
• pp.1740-1746
• /
• 2006

Enrichment techniques led to the isolation of a Pseudomonas sp. strain P2 from municipal waste-contaminated soil sample, which could utilize different isomers of a commercial mixture of 4-nonylphenol when grown in the presence of phenol. The isolate was identified as Pseudomonas sp., based on the morphological, nutritional, and biochemical characteristics and 16S rDNA sequence analysis. The ${\beta}$-ketoadipate pathway was found to be involved in the degradation of phenol by Pseudomonas sp. strain P2. Gas chromatography-mass spectrometric analysis of the culture media indicated degradation of various major isomers of 4-nonylphenol in the range of 29-50%. However, the selected ion monitoring mode of analysis of biodegraded products of 4-nonylphenol indicated the absence of any aromatic compounds other than those of the isomers of 4-nonylphenol. Moreover, Pseudomonas sp. strain P2 was incapable of utilizing various alkanes individually as sole carbon source, whereas the degradation of 4-nonylphenol was observed only when the test organism was induced with phenol, suggesting that the degradation of 4-nonylphenol was possibly initiated from the phenolic moiety of the molecule, but not from the alkyl side-chain.

• 한국축산식품학회지
• /
• 제37권4호
• /
• pp.606-616
• /
• 2017

The objective of this research was to investigate the effects microbial transglutaminase (mTGs) on the physicochemical, microbial and sensory properties of kefir produced by using mix cow and soymilk. Kefir batches were prepared using 0, 0.5, 1 and 1.5 Units m-TGs for per g of milk protein. Adding m-TGs to milk caused an increase in the pH and viscosity and caused a decrease in titratable acidity and syneresis in the kefir samples. Total bacteria, lactobacilli and streptococci counts decreased, while yeast counts increased in all the samples during storage. Alcohols and acids compounds have increased in all the samples except in the control samples, while carbonyl compounds have decreased in all the samples during storage (1-30 d). The differences in the percentage of alcohols, carbonyl compounds and acids in total volatiles on the 1st and the 30th d of storage were observed at 8.47-23.52%, 6.94-25.46% and 59.64-63.69%, respectively. The consumer evaluation of the kefir samples showed that greater levels of acceptability were found for samples which had been added 1.5 U m-TGs for per g of milk protein.

• 한국염색가공학회지
• /
• 제27권4호
• /
• pp.261-269
• /
• 2015

Two new D-${\pi}$-A dyes were synthesized by the condensation reaction between active methyl and aromatic aldehyde and its biothiol sensing properties in DMSO/water were investigated by UV-vis spectroscopy. Upon addition of $Hg^{2+}$, the solution of D-${\pi}$-A dyes showed color change and the absorption band shows a formation of a dye-$Hg^{2+}$ coordination complex. These dyes exhibited high selectivity for $Hg^{2+}$ as compared with other cations. The dye-$Hg^{2+}$ could be recovered by adding glutathion(GSH). The absorption intensity of dye-$Hg^{2+}$ increased only by the addition of glutathione(GSH). The competition experiments revealed that no obvious interference was observed by performing the titration with the mixture of glutathione(GSH) and other amino acids. The results indicated that these D-${\pi}$-A dyes were highly selective for glutathione(GSH) detection.

• Macromolecular Research
• /
• 제12권4호
• /
• pp.384-390
• /
• 2004

Single-walled carbon nanotubes (SWNTs) have been chemically modified through the formation of carboxylic acid functionalities or by grafting octadecylamine and polystyrene onto them. We purified SWNTs with nitric acid to remove some remaining catalysts and amorphous carbon materials. After purification, we broke the carbon nanotubes and shortened their lengths by using a 3:1 mixture of concentrated sulfuric acid and nitric acid. During these purification and cutting processes, carboxylic acid units formed at the open ends of the SWNTs. Octa-decylamine and amino-terminated polystyrene were grafted onto the cut SWNTs by condensation reactions between the amine and carboxylic acid units. The cut SWNTs did not disperse in organic solvents, but the octadecylamine-grafted and polystyrene-grafted SWNTs dispersed well in dichloromethane and aromatic solvents (e.g., benzene, toluene). Composites were prepared by mixing polystyrene with the octadecylamine-grafted or polystyrene-grafted SWNTs. Each composite had a higher dynamic storage modulus than that of a pristine polystyrene. The composites exhibited enhanced storage moduli, complex viscosities, and unusual non-terminal behavior when compared with a monodisperse polystyrene matrix because of the good dispersion of carbon nanotubes in the polystyrene matrix.

• Bulletin of the Korean Chemical Society
• /
• 제34권5호
• /
• pp.1521-1524
• /
• 2013

N-Propylsulfamic acid supported onto magnetic $Fe_3O_4$ nanoparticles (MNPs-PSA) was used as an efficient and magnetically recoverable catalyst for synthesis of 2H-Indazolo[2,1-b]phthalazine-1,6,11(13H)-trione derivatives from the three-component, one-pot condensation reaction of phthalhydrazide, aromatic aldehydes and cyclic 1,3-diones, in good to excellent yields at $100^{\circ}C$ under solvent-free conditions. The catalyst was easily separated with the assistance of an external magnetic field from the reaction mixture and reused for several consecutive runs without significant loss of its catalytic efficiency. In order to compare, the synthesis of 2H-Indazolo[ 2,1-b]phthalazine-1,6,11(13H)-trione derivatives in the presence of catalytic amount of sulfamic acid (SA) under same reaction condition was also reported.