• Title/Summary/Keyword: physicochemical

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Hierarchical multiscale modeling for predicting the physicochemical characteristics of construction materials: A review

  • Jin-Ho Bae;Taegeon Kil;Giljae Cho;Jeong Gook Jang;Beomjoo Yang
    • Computers and Concrete
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    • v.33 no.3
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    • pp.325-340
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    • 2024
  • The growing demands for sustainable and high-performance construction materials necessitate a deep understanding of their physicochemical properties by that of these heterogeneities. This paper presents a comprehensive review of the state-of-the-art hierarchical multiscale modeling approach aimed at predicting the intricate physicochemical characteristics of construction materials. Emphasizing the heterogeneity inherent in these materials, the review briefly introduces single-scale analyses, including the ab initio method, molecular dynamics, and micromechanics, through a scale-bridging technique. Herein, the limitations of these models are also overviewed by that of effectively scale-bridging methods of length or time scales. The hierarchical multiscale model demonstrates these physicochemical properties considering chemical reactions, material defects from nano to macro scale, microscopic properties, and their influence on macroscopic events. Thereby, hierarchical multiscale modeling can facilitate the efficient design and development of next-generation construction.

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

  • Kim, Yoon Ji;Kim, Youn-Tae;Han, Weon Shik;Lee, Seunghak;Choung, Sungwook
    • Journal of Soil and Groundwater Environment
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    • v.24 no.2
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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.

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

  • Lee, Eui-Seok;Lee, Hyong-Ju;Bae, Jae-Seok;Kim, Yong-Kuk;Lee, Jong-Hyeouk;Hong, Soon-Taek
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.4
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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.

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

  • Ryu, Ji-Hye;Kwon, Yong-Suk;Kim, Kyoung-Mi;Lee, Jin-Young
    • Journal of the Korean Society of Food Culture
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    • v.29 no.6
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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).

Polyacetylenic compounds from Atractylodes rhizomes

  • Kim, Jung-Hoon
    • The Korea Journal of Herbology
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    • v.31 no.5
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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.

The Study of Acceptance and Physicochemical Characteristics of Beef Consomme by Boiling Time (가열시간에 따른 Beef Consomme의 기호도 및 이화학적 특성에 관한 연구)

  • 김용식;장명숙
    • Korean journal of food and cookery science
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    • v.19 no.3
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    • pp.271-279
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    • 2003
  • This study was conducted to investigate the sensory and physicochemical properties of beef consomme made with different boiling times (1, 2, 3 and 4hrs). The sensory properties were evaluated with respect to both the acceptability (color, smell, mouth feel, taste, overall acceptability) and intensity characteristics (color, smell, clarify, taste). From the results, the 3hr treatment was most favored for color, smell, mouth feel, taste and overall acceptability, from the sensory evaluation tests. According to a quantitative descriptive analysis of the sensory evaluation for the product, the color, smell and taste gave higher scores with increases in the boiling time. As for the physicochemical characteristics, the pH was increased with increasing boiling time. The reducing sugars, turbidity and viscosity increased with increasing boiling time. The colorimetric lightness values (L) decreased, and redness (a), yellowness(b) and color difference values (ΔE) increased with increasing boiling time. There were 18 free amino acids identified; the alanine, glutamic acid, arginine and leucine contents were high in the free amino acids of the consomme made with different boiling times. There were 3 free sugars identified, glucose, fructose and sucrose. The free sugar contents increased with increasing boiling time. There were changes in the mineral contents of the consomme made with different boiling time; with high K, Na and P contents. The mineral contents increased with increasing, boiling time. The results showed the consomme made by boiling for 3hrs was superior in both its sensory and physicochemical qualities.

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
    • Food Science of Animal Resources
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    • v.42 no.3
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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.

Effect of Physicochemical Parameter on PASS-100 Flocculation (PASS-100을 이용한 응집처리시 물리.화학적 인자의 영향)

  • 이상일;서인석;박승국
    • Journal of environmental and Sanitary engineering
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    • v.10 no.2
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    • pp.30-35
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    • 1995
  • In this research effect of physicochemical parameter on flocculation using PASS-100 were evaluated. pEt flocculant dosage, mixing intensity and detention time were adopted as experimental variables. The physicochemical parameter( p% mixing intensity and mixing time ) were important Parameter on flocculation performance. Effluent pH range for effective flocculation was 4.5-7. Optimum Gt$_{d}$ range was 20,000-30,000 and its range similar to alum flucculation. Rapid mixing was very important parameter to floe formation in PASS- 100 flocculation. Whereas, slow mixing did not affect to the removal efficiency at settling time for 30minute or more.

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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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    • v.30 no.1
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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.

Characteristics of Physicochemical Factors of Inchon Dock Ecosystem, Korea (인천항 선거내 해양환경의 이화학적 특성)

  • 유종수;이인규;이진환
    • The Korean Journal of Ecology
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    • v.20 no.1
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    • pp.61-68
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    • 1997
  • Due to its lack of wave action and tide ecosystem in Inchon dock lacks in marine characteristics. Structural condition in the dock is artificially similar to that of lake. The purposes of this study was to clarify the water quality, to provide the basic physicochemical data and tl resolve the causation of ?미 blooming. Samples were obtained monthly from four stations in Inchon dock during January to December, 1991. Water temperature ranged from $2.7^{\circ}C$ to $27.6^{\circ}C$ under the strong influence of air temperature. Salinity varied between 24.7%-30.4% thus being influenced by freshwater discharged from a spring. Dissolved oxygen was concentrated from 0.1-13.92 mg/l and suspended solids were 6.9-231.0 mg/l. The physicochemical factors were similar to those investigated 10 years ago. However, increased concentration of nitrogenous nutrients initiated ?미 blooming and its process was accelerated to reach eutrophication. Algal blooming was proceeded in March and August.

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