• Asian Journal of Atmospheric Environment
• /
• 제2권2호
• /
• pp.102-108
• /
• 2008

In China, energy and environmental problems are becoming serious owing to rapid economic development. Coal is the most problematic energy source because it causes indoor and outdoor air pollution, acid rain, and global warming. One type of clean coal technology that has been developed is the coal-biomass briquette (or bio-briquette, BB) technique. BBs, which are produced from pulverized coal, biomass (typically, agricultural waste), and a sulfur fixation agent (slaked lime, $Ca(OH)_2$) under high pressure without any binder, have a high sulfur-fixation effect. In addition, BB combustion ash, that is, the waste material, can be used as a neutralization agent for acidic soil because of its high alkalinity, which originates from the added slaked lime. In this study, we evaluated the suitability of alternative biomass sources, namely, aquatic plants, as a BB constituent from the perspective of their use as a source of energy. We selected three types of aquatic plants for use in BB preparation and compared the fuel, handling, and environmental characteristics of the new BBs with those of conventional BBs. Our results showed that air-dried aquatic plants had a higher calorific value, which was in proportion to their carbon content, than agricultural waste biomass; the compressive strength of the new BBs, which depends on the lignin content of the biomass, was high enough to bear long-range intracontinental transport in China; and the new BBs had the same emission control capacity as the conventional BBs.

• Journal of the Korean Wood Science and Technology
• /
• 제34권6호
• /
• pp.36-43
• /
• 2006

유동형 급속열분해기 (fluidized bed type fast pyrolyzer, 용량 400 g/h)를 이용하여 너도밤나무와 침엽수 혼합재(독일가문비나무/전나무, 50:50) 에서 바이오오일을 생산하였다. 목질바이오매스의 열분해는 약 $470{\pm}5^{\circ}C$에서 1~2초 동안 진행되었다. 목질바이오매스의 열분해 생성물의 조성은 너도밤나무의 경우 바이오오일 60%, 탄 9% 그리고 가스가 31% 정도 생산되었으며, 침엽수 혼합재는 바이오일 49%, 탄 9%, 그리고 42% 가량의 가스가 생성되었다. 두 종류의 목질바이오매스에서 생산된 바이오오일의 수분함량은 약 17~22%이었으며, 밀도는 수종에 관계없이 $1.2kg/{\ell}$이었다. 바이오오일의 원소 조성은 탄소 45%, 산소 47%, 수소 7%, 그리고 질소 1%로 일반적인 목질바이오매스와 큰 차이는 없는 것으로 나타났다. 그러나 화석자원에서 생산되는 오일류와 비교하여 바이오일은 산소함량이 매우 높았고 황은 전혀 포함되어 있지 않았다. 바이오오일의 GC 분석 결과 총 90여종의 방향족(aromatic) 또는 비방향족(non-aromatic) 저분자량 화합물이 검출되었으며 이들의 함량은 바이오오일 전건중량의 31~33%로 분석되었다.

• 현장농수산연구지
• /
• 제15권1호
• /
• pp.183-202
• /
• 2013

인삼에 기생하는 해충을 억제하는 석회유황합제를 응용하되 피해를 줄이고 효과를 증진시키는 석회유황합제 복합체를 적용하고자 했다. 특히, 석회유황합제는 휴면기에만 사용하였으나 석회유황합제 복합체를 응용하여 인삼의 병해가 가장 많은 여름 장마기 전후에 사용이 가능한 것으로 나타났다. 묘삼재배에서 석회유황합제에 첨가한 복합제별 비교는 주당 무게 평균값 기준으로 했을 때 KHCO₃ > NaHCO₃ > MgSO₄ 순으로 좋은 결과를 보였다. 또한 생육상태 및 근장에서 묘삼으로 조건도 갖추고 있었다. NaHCO₃를 이용한 희석비율 효과는 석회유황합제 200배 희석액에 중탄산나트륨를 첨가한 것이 주당 무게가 가장 많이 나왔으며 체형도 좋은 것으로 나타났다. 또한, 석회유황합제 복합제 처리간격별 비교는 주당 무게 평균값 기준으로 20일 > 30일 > 40일 > 10일 순을 보였다. 5년근 인삼에 미치는 석회유황합제 복합체의 효과에 대한 현장 시험에서도 석회유황합제에 첨가한 복합제별 비교는 주당 무게 평균값 기준으로 했을 때 NaHCO₃가 좋은 결과를 보였다. 무처리구와는 큰 차이를 보였으나 처리구 상호 간에는 큰 유의차는 없었다. 처리 농도 효과도 근중으로 보았을 때 석회유황합제 200배 희석액에 중탄산나트륨를 첨가한 것이 주당 무게가 가장 많이 나왔으며 체형도 좋은 것로 나타났다. 석회유황합제복합체 5년생 인삼의 생육에 미치는 석회유황합제 복합체의 영향은 주당 무게 평균값 기준으로 20일 > 30일 > 40일 > 10일 순으로 나타났다. 따라서 묘삼과 5년근 인삼의 해충 방지에는 석회유황합제에 복합체 재료로 중탄산나트륨(KHCO₃)을 이 용하여 200배 이상 희석하여 예방용으로 장마전에 20일 간격으로 2~3회 살포하면 효과가 큰 것으로 나타났다.

• Journal of Microbiology
• /
• 제45권2호
• /
• pp.105-112
• /
• 2007

The objective of this study was to analyze the phylogenetic composition of bacterial community in the soil of an earth-cave (Niu Cave) using a culture-independent molecular approach. 16S rRNA genes were amplified directly from soil DNA with universally conserved and Bacteria-specific rRNA gene primers and cloned. The clone library was screened by restriction fragment length polymorphism (RFLP), and representative rRNA gene sequences were determined. A total of 115 bacterial sequence types were found in 190 analyzed clones. Phylogenetic sequence analyses revealed novel 16S rRNA gene sequence types and a high diversity of putative bacterial community. Members of these bacteria included Proteobacteria (42.6%), Acidobacteria (18.6%), Planctomycetes (9.0 %), Chloroflexi (Green nonsulfur bacteria, 7.5%), Bacteroidetes (2.1%), Gemmatimonadetes (2.7%), Nitrospirae (8.0%), Actinobacteria (High G+C Gram-positive bacteria, 6.4%) and candidate divisions (including the OP3, GN08, and SBR1093, 3.2%). Thirty-five clones were affiliated with bacteria that were related to nitrogen, sulfur, iron or manganese cycles. The comparison of the present data with the data obtained previously from caves based on 16S rRNA gene analysis revealed similarities in the bacterial community components, especially in the high abundance of Proteobacteria and Acidobacteria. Furthermore, this study provided the novel evidence for presence of Gemmatimonadetes, Nitrosomonadales, Oceanospirillales, and Rubrobacterales in a karstic hypogean environment.

• 한국토양비료학회지
• /
• 제47권2호
• /
• pp.113-119
• /
• 2014

Arsenic and its compounds which is one of the most toxic elements that can be found naturally on earth in small concentrations are used in the production of pesticides, herbicides, and insecticides. Most arsenic that cannot be mobilized easily when it is immobile is also found in conjunction with sulfur in minerals such as arsenopyrite (AsFeS), realgar, orpiment and enargite. In this investigation we observed the leaching of arsenic in soils amended with several levels of gravel size of arsenopyrite collected from a road construction site. Soil and gravel size of arsenopyrite were characterized by chemical and mineralogical analyses. Results of XRF analysis of arsenopyrite indicated that the proportion of arsenate was 0.075% (wt $wt^{-1}$) while the maximum amount of arsenic in soil samples was 251.3 mg $kg^{-1}$. Cumulative amounts of effluent collected from the bottom of the soil column for different mixing rate of the gravel were gradually increased where proportion of the gravel mixed was greater than 70% whereas the effluent was stabilized to the maximum after approximately 45 pore volumes of effluent or greater were collected. The arsenic in the effluent was recovered from the soil columns in which the proportion of arsenopyrite gravel was 60% or greater. The total amount of arsenic recovered as effluent was increased with increasing proportion of gravel in a soil, indicating that the arsenic in the effluent was closely related with gravel fraction of arsenopyrite.

• 한국자동차공학회논문집
• /
• 제17권3호
• /
• pp.81-89
• /
• 2009

In this experimental study, the effects of clean alternative fuels compatible with diesel combustion on nano-sized particle emission characteristics were investigated in a 0.5L auto-ignited single-cylinder engine with a compression ratio of 15. Because the number concentration of nano-sized particles emitted by automotive engine, that are suspected of being hazardous to human health and environment, might increase with engine fuel considerably and recently attracted attention. So a ultra-low sulfur diesel(ULSD), BD100(100% bio-diesel) and Di-Methyl Ether(DME) fuels used for this study. And, as a particle measuring instrument, a fast-response particle spectrometer (DMS 500) with heated sample line was used for continuous measurement of the particle size and number distribution in the size range of 5 to 1000nm (aerodynamic diameter). As this research results, we found that this measurements involving the large proportion of particles under size order of 300nm and number concentration of $4{\times}10^9$ allowed a single or bi-modal distribution to be found at different engine load conditions. Also the influence of oxygen content in fuel and the catalyst could be a dominant factor in controlling the nano-sized particle emissions in auto-ignited engine.

• Mass Spectrometry Letters
• /
• 제12권4호
• /
• pp.192-199
• /
• 2021

Alpine glaciers harbor a large quantity of bio-labile dissolved organic matter (DOM), which plays a pivotal role in global carbon cycling as glacial-fed streams are headwaters of numerous large rivers. To understand the complexity, origin, and fate of DOM in glaciers and downstream-linked streams and lakes, we elucidated the molecular composition of DOM in two different Tibetan Plateau glaciers, eight glacial-fed streams and five lakes, using an ultrahigh-resolution 15 Tesla Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The compositional changes of the DOM samples revealed that glacier DOM mostly exhibited sulfur-containing organic compounds (CHOS species). We also found that aliphatic formulae contributed more than 50% of the total abundance of assigned molecules in glacier samples, and those compounds were significantly related to CHOS species. The CHO proportions of glacial-fed streams and lakes samples increased with increasing distance from glacial terminals. The relative contribution of terrestrial-derived organics (i.e., lignins and tannins) declined while microbial-originated organics (aliphatics) increased with increasing elevation. This suggested the gradual input of allochthonous materials from non-glacial environment and the degradation of microbe-derived compounds along lower elevations. Alpine glaciers are retreating as a result of climate change and they nourished numerous streams, rivers, and downstream-linked lakes. Therefore, the interpretations of the detailed molecular changes in glacier ice, glacial-fed streams, and alpine lakes on the Tibetan Plateau could provide broad insights for understanding the biogeochemical cycling of glacial DOM and assessing how the nature of DOM impacts fluvial ecosystems.

• 한국식품저장유통학회지
• /
• 제30권1호
• /
• pp.52-64
• /
• 2023

100 different yeast colonies were isolated from spontaneously fermented kiwis, persimmons, apples, pears, watermelons, grapes, grape fruits, peachs, and plums, and selected yeast strains were used to produce kiwi-persimmon mixed wine (KPMW). Among the isolates, five representative strains exhibited tolerance to sucrose, alcohol, pH, and potassium metabisulfite when compared with the control yeast strain (Saccharomyces cerevisiae KCCM 12615). All five yeast strains (Y4, Y10, Y28, Y78, and Y81) exhibited 99% 26S rDNA sequence similarity to S. cerevisiae. The pH, acidity, Brix, reducing sugar, alcohol, and organic acid contents were consistent in KPMW prepared from the S. cerevisiae KCCM 12615 and Y28 strains. KPMW made from the Y4, Y10, and Y28 strains exhibited lower quantities of free sugars than those of the KPMW made from the other yeast strains. The level of ethyl esters in KPMW prepared from the Y28 was higher than that in the other KPMWs. All strains, except for Y28, produced lower concentrations of sulfur and ketone compounds. Furthermore, the KPMW produced by the Y28 strains had total phenolic contents with 1.1 g/L, with DPPH and ABTS radical scavenging activities of 57.06% and 55.62%, respectively, and a FRAP assay value of 0.72. Our results suggest that Y28 is a promising yeast strain for producing high-quality wines.

• 미생물학회지
• /
• 제55권3호
• /
• pp.309-312
• /
• 2019

본 연구에서는 폐수처리장의 바이오필터로부터 Comamonas sp. NLF-7-7 균주를 분리하고 유전체서열을 PacBio RS II와 Illumina HiSeqXten 플랫폼을 사용하여 분석하였다. 염색체의 크기는 3,333,437 bp로 G + C 구성 비율은 68.04%, 총 유전자수는 3,197개, rRNA는 9개 및 tRNA는 49개로 구성되었다. 본 유전체는 오염물질분해와 플록형성에 관여하는 황산화 경로 유전자(SoxY, SoxZ, SoxA 및 SoxB)와 플록형성 경로 유전자(EpsG, EpsE, EpsF, EpsG, EpsL 및 glycosyltransferase)를 포함하고 있다. 이러한 Comamonas sp. NLF-7-7 균주는 폐수를 정화하는데 활용될 수 있다.

• Toxicological Research
• /
• 제23권4호
• /
• pp.311-319
• /
• 2007

Elevated blood levels of homocysteine (a sulfur-containing amino acid) have been linked to increased risk of cerebrovascular disease including Alzheimer's disease. A recent study suggests that elevated homocysteine levels may lead to replicative senescence in vitro called 'permanent arrest of cell cycle' caused by oxidative stress. In this study, serum homocysteine level in rat was reduced by Lentinus edodes-powder diet, resulting in the reduced level of oxidative stress in rat brain. In addition, homocysteine-induced replicative senescence treated with or without Lentinus edodes-powder was analyzed by population doubling in vitro. The Lentinus edodes-powder induced a increased number of population doubling in primary neuron cell isolated from rat-cerebral cortex. This indicates that Lentinus edodes-powder would delay a homocysteine-induced aging of neuron cells in brain, showing a possible role in preventing cerebrovascular diseases including Alzheimer's disease.