• 제목/요약/키워드: Physicochemical properties

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Influence of Functionalization on Physicochemical Properties of Multi-walled Carbon Nanotubes/Epoxy Matrix Nanocomposites

  • Seo, Min-Kang;Park, Soo-Jin
    • Bulletin of the Korean Chemical Society
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    • 제30권1호
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    • pp.124-128
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    • 2009
  • In this study, the effect of multi-step purification or functionalization on physicochemical properties of multi-walled carbon nanotubes (MWNTs)/epoxy (EP) nanocomposites was investigated. The nanocomposites containing multi-step purified MWNTs showed a stronger influence on $T_g$ and increased in mechanical properties in comparison to nanocomposites containing the same amount of only purified MWNTs. Consequently, the multi-step purification of MWNTs led to an improvement of thermomechanical properties of nanocomposites, resulting from improving the intermolecular interaction of MWNTs in epoxy matrix resins.

불특정 오염부지에 대한 잠재적 오염물질 선정 및 물리·화학적 특성 정보화 (Identification of Workflow for Potential Contaminants and their Physicochemical Properties)

  • 김윤지;김연태;한원식;이승학;정성욱
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제24권2호
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    • pp.8-22
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    • 2019
  • Among numerous chemicals used globally, the number of emerging contaminants is increasing. Numerical modeling for contaminant fate and transport in the subsurface is critical to evaluate environmental and health risk. In general, such models require physicochemical properties of contaminants as input values, which can be found in numerous chemical databases (DB). However, there exist lack of information specific to recently emerging contaminants, which requires estimation of physicochemical properties using regression programs. The purpose of the study is to introduce the workflow for identifying physicochemical properties of potential contaminants utilizing numerous chemical DBs, which frequently lists up potential contaminants for estimating chemical behavior. In this review paper, details of several chemical DBs such as KISChem, TOXNET, etc. and regression programs including EPI $Suite^{TM}$, ChemAxon, etc. were summarized and also benefit of using such DBs were explained. Finally, a few examples were introduced to estimate predominant phase, removal ratio, partitioning, and eco-toxicities by searching or regressing physicochemical properties.

시판 강정류의 이화학적 특성 및 소비자 기호도에 관한 연구 (Physicochemical Properties and Consumer Acceptability of Commercial Gang-jeong)

  • 류지혜;권용석;김경미;이진영
    • 한국식생활문화학회지
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    • 제29권6호
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    • pp.637-647
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    • 2014
  • This study was conducted to examine the physicochemical properties and consumer acceptability of commercial Gang-jeong. The samples used in this study were nine different Gang-jeong as commercial products. To accomplish this research, the physicochemical properties of nine samples, including moisture, crude lipid, sugar contents, acid value, color values, and texture, were measured. In addition, consumer panels evaluated the overall acceptability, appearance, flavor, sweetness, and texture of samples using a 9-point Likert type scale as well as the perceived intensities of sweetness and rancid odor by a 9-point Just-About-Right (JAR) scale. All data were statistically analyzed using One-way ANOVA, Principle Component Analysis, Hierarchical Cluster Analysis, and Pearson's Correlation Analysis. All physicochemical properties were significantly different among the samples (p<0.001). Analyses of consumer acceptability and JAR ratings of the nine samples showed significant differences (p<0.001).

신선초 분말의 위생화를 위한 오존처리와 감미선 조사와의 비교 효과 (Comparative Effect of ${\gamma}$-Irradiation and Ozone Treatment for the Improvement of Hygienic Quality of Dried-Angelica Keiskei Koidz Powder)

  • 변명우;육홍선;김정옥;김종군;이현자
    • 한국식품위생안전성학회지
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    • 제12권2호
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    • pp.111-116
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    • 1997
  • For the purpose of improving hygienic quality of dried-Angelica Keiskei Koidz powder, the effect of ozone treatment and gamma irradiation on the microbial decontamination and physicochemical properties were investigated. Gamma irradiation at 5 to 7.5 kGy resulted in sterilizing total aerobic bacteria, molds and coliforms below detective levels, while ozone treatment for 8 hours up to 18 ppm did not sufficiently eliminate the total aerobic bacteria of the sample. The physicochemical properties of the sample were not changed by gamma irradiation up to 7.5 kGy, whereas, ozone treatment caused remarkable changes in pH, TBA value, chlorophyll, carotenoid and fatty acid compositions. Therefore, this investigation demonstrated conclusively that gamma irradiation was more effective than ozone treatment for decontaminating and sterilizing the dried-Angelica Keiskei Koidz powder, with minimal effect on the physicochemical properties analyzed.

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산국(山菊) 에탄올 추출물의 이화학적 특성에 대한 추출조건의 최적화 (Optimization of Extraction Conditions for Physicochemical Properties of Ethanol Extracts from Chrysanthemum boreale)

  • 권중호;박난영;이기동;정용진
    • 한국식품영양과학회지
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    • 제27권4호
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    • pp.585-590
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    • 1998
  • To renew interest in Chrysanthemum boreale as a traditional food material, response surface methodology was used for optimizing extraction conditions and monitoring physicochemical properties of ethanol extracts from Chrysanthemum petal. The phenolic compounds of ethanol extracts were minimized in 87ml/g(solvent per sample), 21%(ethanol concentration), and 15 hours(extraction time). The physicochemical properties of ethanol extracts were maximized in the conditions of 115ml/g, 98% and 16 hours on yellow color intensity, 143ml/g, 75% and 19 hours on carotenoid content, and 148ml/g, 53% and 18 hours on soluble solid content. Optimum ranges of extraction condition for physicochemical properties of Chrysanthemum boreale were 130~150ml/g, 70~85% and 20~28 hours, respectively. Predicted values at the optimum extraction condition were in good agreement with experimental values.

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포장재가 멸치조미가공품의 저장 중 이화학적 품질 특성에 미치는 영향 (Effects of Packaging Materials on the Physicochemical Characteristics of Seasoned Anchovies During Storage)

  • 이의석;이형주;배재석;김용국;이종혁;홍순택
    • 동아시아식생활학회지
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    • 제23권4호
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    • pp.461-469
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    • 2013
  • This research is performed to investigate the changes in the physicochemical properties and microbial growths of seasoned anchovies with various packaging materials (PET/CPP : polyethylene terephthalate/cast polypropylene, PET/EVOH : polyethylene terephthalate/ethylene-vinyl alcohol, PET/AL/LDPE: polyethylene terephthalate/aluminum/low density polyethylene), which are stored at various temperatures (25, 35, $45^{\circ}C$) for 60 days. Generally, it is being observed that changes in physicochemical properties (i.e., moisture content, color, brown intensity, TBA value, TMA, VBN etc) of seasoned anchovies are significant when stored at higher temperatures. Particularly, the packaging materials are found to influence substantially on the physicochemical properties of seasoned anchovies. With packaging materials of high oxygen transmission rates and moisture vapor transmission rates (i.e., PET/CPP), the changes in physicochemical properties of seasoned anchovies are significant, while being low with low oxygen transmission rates and low moisture vapor transmission rates (i.e., PET/EVOH). In addition, results of microbial growths in seasoned anchovies show that significant increases in total aerobic bacteria counts (about 100-fold after 60 day of storage) are observed in samples with packaging materials of high oxygen transmission rates and moisture vapor transmission rates (i.e, PET/CPP), while with only small increases for samples of low oxygen transmission rates and low moisture vapor transmission rates (i.e., PET/EVOH). Based on the changes in the physicochemical properties and results of microbial growths, it is being concluded that PET/EVOH film is suitable for the packaging of seasoned anchovies.

보리 품종의 이화화적 및 호화 특성 비교 (Comparison of the Physicochemical and Gelatinization Properties of Various Barley Cultivars)

  • 탁은숙;정희남
    • 한국식생활문화학회지
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    • 제37권4호
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    • pp.345-353
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    • 2022
  • This study compared the physicochemical and gelatinization properties of naked barley, tetrastichum barley, and waxy barley. Compared to tetrastichum barley and waxy barley, naked barley had shorter and rounder grains with a 1.43 length/width ratio. Tetrastichum barley had lower crude protein, crude lipid, and crude ash content and higher amylose content compared to naked barley and waxy barley. The L, a, b color values of waxy barley were significantly higher than those of naked barley and tetrastichum barley. The water absorption index (WAI) and the water soluble index (WSI) were highest in waxy barley. The X-ray diffraction pattern was type A in all samples, and the peak intensity was highest in waxy barley. The maximum viscosity, cooling viscosity, breakdown, and setback of amylogram properties were the highest in tetrastichum barley. The thermal properties through the differential scanning calorimeter showed that the waxy barley had higher values of the onset, peak, conclusion temperature and enthalpy (?H). In conclusion, the variety of barley influenced the physicochemical and gelatinization properties, which could be important factors in the manufacture of processed foods. These results would thus useful inputs for the manufacturing of these foods using barley.

Polyacetylenic compounds from Atractylodes rhizomes

  • Kim, Jung-Hoon
    • 대한본초학회지
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    • 제31권5호
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    • pp.25-39
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    • 2016
  • Objectives : Atractylodes rhizomes, which have been widely used to treat gastrointestinal disorders, consist of numerous chemical compounds. Polyacetylenes are the parts of characteristic compounds of importance required to understand the therapeutic properties of Atractylodes rhizomes. It is necessary to understand the physicochemical and pharmacological properties of polyacetylenes in the Atractylodes rhizomes.Methods : The literatures from 1970 to January 2016 were searched using Korean and international electronic databases. The chemical structures of polyacetylenes were drawn by structure-drawing software.Results : The reported polyacetylenes were classified by their chemical skeletons and original resources, and their physicochemical and pharmacological features were discussed. Polyacetylenes with skeletal moieties were reported, such as diene-diyne types (two double and two triple carbon-bonds), triene-diyne types (three double carbon bonds and two triple carbon bonds), and monoene-diyne types (one double carbon bonds and two double carbon bonds), with various functional groups. Atractylodin was most frequently reported from many Atractylodes species. Atractylodin-related polyacetylenes showed chemical instability in both high and freezing temperatures. Processing of the Atractylodes rhizomes by stir-frying with bran could affect the contents of polyacetylenes and their bioavailability in vivo. Several polyacetylenes showed structure-related anti-inflammatory activities and gastrointestinal activities.Conclusion : Polyacetylene compounds in Atractylodes rhizomes were based on three chemical backbones and showed diverse physicochemical and pharmacological features. The present study provides structural, physicochemical, and pharmacological information of polyacetylene from Atractylodes rhizomes. This information provides fundamental data for further research.

Drying Characteristics and Physicochemical Properties of Semi-Dried Restructured Sausage Depend on Initial Moisture Content

  • Kim, Dong-Hyun;Kim, Yea Ji;Shin, Dong-Min;Lee, Jung Hoon;Han, Sung Gu
    • 한국축산식품학회지
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    • 제42권3호
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    • pp.411-425
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    • 2022
  • Semi-dried restructured sausages are restructured meat products with a high nutritional and economic value. However, excessively long drying times can have negative effects on the energy consumption, texture, and sensory properties of semi-dried restructured sausages. The objective of this study was to investigate the effects of different water contents on the drying and physicochemical characteristics of semi-dried restructured sausages. Sausages were prepared with different initial moisture contents (0%-50%) and drying time (0-580 min). The drying characteristics, including the drying rate, effective moisture diffusivity, and water activity of sausage were significantly improved as the initial moisture content was increased. When the initial moisture content of the sausage was 50%, physicochemical properties, such as color, porosity, shear force, and volatile basic nitrogen, were improved the most along with the decreased drying time. Scanning electron microscopy data showed greater porosity and pore size in sausages with the increase of initial moisture content. Collectively, our data suggest that an increase in the initial moisture content of semi-dried restructured sausages improves their drying characteristics and physicochemical properties.

수작업 박피밤과 화염박피 밤의 물리화학적 특성 (The Physicochemical Properties of Hand-Peeled and Flame-Peeled Chestnuts)

  • 김종훈;박재복;최창현
    • Journal of Biosystems Engineering
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    • 제24권5호
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    • pp.407-414
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    • 1999
  • To evaluate the quality of flame-peeled chestnuts, their physical and chemical properties were analyzed. The physicochemical properties of flame-peeled chestnuts, including geometrical shape, texture and chemical composition, were compared to those of hand-peeled ones. For the flame-peeled chestnuts, some properties in heated and non-heated sections were separately analyzed. The color, texture such as springness, cohesiveness, adhesiveness, hardness and chewiness, moisture content, and reducing sugar of the heated section of the flame-peeled chestnuts were significantly different with their non-heated section. But the physicochemical properties of the non-heated section of the flame-peeled chestnuts were similar to those of the hand-peeled ones.

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