• Title/Summary/Keyword: gels

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Fractal Nature of Magnetic Colloidal Dispersion with Cobalt Iron Oxide and Metal Iron Particles

  • Yoon, Kwan Han;Lee, Young Sil
    • Korean Chemical Engineering Research
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    • v.60 no.1
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    • pp.125-131
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    • 2022
  • The microstructure of highly aggregated colloidal dispersions was investigated by probing the rheological behavior of magnetic suspensions. The dynamic moduli as functions of frequency and strain amplitude are shown to closely resemble that of colloidal gels indicating the formation of network structure. The two types of characteristic critical strain amplitudes, γc and γy, were characterized in terms of the changing microstructure. The amplitude of γc indicates the transition from linear to nonlinear viscoelasticity and depends only on particle volume fraction not magnetic interactions. The study of scaling behavior suggests that it is related to the breakage of interfloc, i.e., floc-floc structure. However, yielding strain, γy, was found to be independent of particle volume fraction as well as magnetic interaction. It relates to extensive deformation resulting in yielding behavior. The scaling of elastic constant, Ge, implies that this yielding behavior and hence γy is due to the breakage of long-range interfloc interactions. Also, the deformation of flocs due to increase strain was indicated from the investigation of the fractal nature.

DEVELOPMENT OF SUSTAINABLE CEMENTLESS MORTARS

  • Keun-Hyeok Yang;Seol Lee;Sang-Ho Nam
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1630-1636
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    • 2009
  • Nine alkali-activated (AA) mortars were mixed and cured at water or air-dried conditions to explore the significance and limitation for the application of the combination of Ba and Ca ions as an alkali-activator. Ground granulated blast-furnace slag (GGBS) was used for source materials, and calcium hydroxide (Ca(OH)2) and barium hydroxide (Ba(OH)2) were employed as alkali activators. Test results clearly showed that the water curing condition was more effective than the air-dried curing condition for the formation of the denser calcium silicate hydrate (C-S-H) gels that had a higher molar Si/Ca ratio, resulting in a higher strength development. At the same time, the introduction of Ba(OH)2 led to the formation of 2CaO·Al2O3·SiO2·8H2O (C2ASH8) hydrates with higher molar Si/Al and Ca/Al ratios. Based on the test results, it can be concluded that the developed cementless mortars have highly effective performance and high potential as an eco-friendly sustainable building material.

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Effect of activator types on cement mortar with polymeric aluminum chloride waste residue

  • Ping Xu;Yuhao Cui;Dong Han;Minxia Zhang;Yahong Ding
    • Advances in concrete construction
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    • v.15 no.3
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    • pp.149-159
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    • 2023
  • Water glass (WG) and sodium sulfate (SS) were used to prepare polymeric aluminum chloride residue cement mortar (PACRM) by single and compound blending with polymeric aluminum chloride waste residue, respectively. The structural strength and textural characteristics examinations showed that PACRM consistency increased by incorporating WG, but decreased by incorporating SS. When WG and SS were compounded, the mortar consistency initially rose before falling. The compressive strength of PACRM increased and then decreased as WG was increased. The mechanical properties of PACRM were better enhanced by SS than WG, showing no strength deterioration. The main reason for the improved mechanical properties of polymeric aluminum chloride waste residue in the presence of activators is the increased precipitation of reactive substances, such as C-S-H gels, calcium silica, and Ca(OH)2. The density of the specimens with PACRM and the degree of aggregation of hydration products were significantly enhanced by generating more hydration products in the mortar. Further, the cracks and pores were significantly reduced, and the matrix structure was continuous and dense at 5% SS doping and 3% compound doping.

Evaluation of Gelation Properties of Salt-Soluble Proteins Extracted from Protaetia brevitarsis Larvae and Tenebrio molitor Larvae and Application to Pork Myofibrillar Protein Gel System

  • Ji Seon Choi;Geon Ho Kim;Ha Eun Kim;Min Jae Kim;Koo Bok Chin
    • Food Science of Animal Resources
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    • v.43 no.6
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    • pp.1031-1043
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    • 2023
  • The purpose of this study was to investigate the functional properties of salt-soluble proteins obtained from Protaetia brevitarsis (PB) and Tenebrio molitor (TM) larvae, the interaction between these proteins and pork myofibrillar protein (MP) in a gel system. The gel properties of salt-soluble protein extracts showed that the PB had a higher viscosity than the TM protein. However, the TM protein had higher gel strength compared with the PB protein. The gelation characteristics of the pork MP gel systems added with lyophilized insect salt-soluble protein powder showed to decrease slightly viscosity compared with MP alone. Adding the TM or PB protein powder did not affect the pork MP's hydrophobicity and sulfhydryl group levels. Furthermore, the protein bands of the MP did not change with the type or amount of insect salt-soluble protein. The cooking yields of the pork MP gels containing PB or TM protein powder were higher than those without insect protein. Regardless of the type of insect salt-soluble protein added, the pork MP's gel strength decreased. Furthermore, as the level of insect powder increased, the surface protein structure became rough and porous. The results demonstrated that proteins extracted from PB and TM larvae interfered with the gelation of pork MP in a gel system.

Effect of Water on Lecithin/Bile/Decane Organogels (레시틴/담즙염/데케인 유기젤에 대한 물의 영향)

  • Eun-ae Chu;Na-hyeon Kim;Min-seok Kang;Kyo-chan Koo;Hee-Young Lee
    • Journal of Adhesion and Interface
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    • v.24 no.4
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    • pp.131-135
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    • 2023
  • Lecithin self-assembles into reverse spherical micelles in organic solvents as an amphiphilic molecule. When additives such as bile salts and water are introduced into lecithin solutions, it induces structural changes in the molecular form of lecithin, leading to the transformation into reverse cylindrical micelles. In this study, we observe the rheological changes of lecithin/bile salt mixtures in a decane system after the addition of water. The resulting mixtures exhibit high viscosity and characteristics of viscoelasticity, suggesting potential applications in various fields such as drug delivery and edible oil gels.

A simple and rapid method for detection of single nucleotide variants using tailed primer and HRM analysis

  • Hyeonguk Baek;Inchul, Choi
    • Journal of Animal Reproduction and Biotechnology
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    • v.38 no.4
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    • pp.209-214
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    • 2023
  • Background: Single nucleotide polymorphisms (SNPs) are widely used genetic markers with applications in human disease diagnostics, animal breeding, and evolutionary studies, but existing genotyping methods can be labor-intensive and costly. The aim of this study is to develop a simple and rapid method for identification of a single nucleotide change. Methods: A modified Polymerase Chain Reaction Amplification of Multiple Specific Alleles (PAMSA) and high resolution melt (HRM) analysis was performed to discriminate a bovine polymorphism in the NCAPG gene (rs109570900, 1326T > G). Results: The inclusion of tails in the primers enabled allele discrimination based on PCR product lengths, detected through agarose gel electrophoresis, successfully determining various genotypes, albeit with some time and labor intensity due to the use of relatively costly high-resolution agarose gels. Additionally, high-resolution melt (HRM) analysis with tailed primers effectively distinguished the GG genotype from the TT genotype in bovine muscle cell lines, offering a reliable way to distinguish SNP polymorphisms without the need for time-consuming AS-PCR. Conclusions: Our experiments demonstrated the importance of incorporating unique mismatched bases in the allele-specific primers to prevent cross-amplification by fragmented primers. This efficient and cost-effective method, as presented here, enables genotyping laboratories to analyze SNPs using standard real-time PCR.

Advancements in Sustainable Plant-Based Alternatives: Exploring Proteins, Fats, and Manufacturing Challenges in Alternative Meat Production

  • Minju Jung;YouKyeong Lee;Sung Ok Han;Jeong Eun Hyeon
    • Journal of Microbiology and Biotechnology
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    • v.34 no.5
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    • pp.994-1002
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    • 2024
  • The rise in plant-based food consumption is propelled by concerns for sustainability, personal beliefs, and a focus on healthy dietary habits. This trend, particularly in alternative meat, has attracted attention from specialized brands and eco-friendly food companies, leading to increased interest in plant-based alternatives. The dominant plant-based proteins, derived mainly from legumes, include soy protein isolates, which significantly impact sensory factors. In the realm of plant-based fats, substitutes are categorized into fat substitutes based on fats and fat mimetics based on proteins and carbohydrates. The production of these fats, utilizing gums, emulsions, gels, and additives, explores characteristics influencing the appearance, texture, flavor, and storage stability of final plant-based products. Analysis of plant-based proteins and fats in hamburger patties provides insights into manufacturing methods and raw materials used by leading alternative meat companies. However, challenges persist, such as replicating meat's marbling characteristic and addressing safety considerations in terms of potential allergy induction and nutritional supplementation. To enhance functionality and develop customized plant-based foods, it is essential to explore optimal combinations of various raw materials and develop new plant-based proteins and fat separation.

Comparison Study on Changes of Antigenicities of Egg Ovalbumin Irradiated by Electron Beam or X-Ray

  • Kim, Mi-Jung;Lee, Ju-Woon;Sung, Nak-Yoon;Kim, Su-Min;Hwang, Young-Jung;Kim, Jae-Hun;Song, Beom-Seok
    • Food Science of Animal Resources
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    • v.34 no.5
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    • pp.570-575
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    • 2014
  • This study was conducted to compare the effects of two forms of radiation (electron and X-ray; generated by an electron beam accelerator) on the conformation and antigenic properties of hen's egg albumin, ovalbumin (OVA), which was used as a model protein. OVA solutions (2.0 mg/mL) were individually irradiated by electron beam or X-ray at the absorbed doses of 0 (control), 2, 4, 6, 8, and 10 kGy. No differences between the two forms of radiation on the structural properties of OVA were shown by spectrometric and electrophoretic analyses. The turbidity of OVA solution increased and the main OVA bands on polyacrylamide gels disappeared after irradiation, regardless of the radiation source. In competitive indirect enzyme-linked immunosorbent assay, OVA samples irradiated by electron beam or X-ray showed different immunological responses in reactions with monoclonal and polyclonal antibodies (immunoglobulin G) produced against non-irradiated OVA. The results indicate that electron beam irradiation and X-ray irradiation produced different patterns of structural changes to the OVA molecule.

Effect of Water Level on the Rheological Properties of Polyvinyl Alcohol/Dimethyl Sulfoxide/Water/Boric Acid Solution Systems (폴리비닐알코올/디메틸술폭시드/물/붕산 용액계에 있어서 물함량이 유변학적 특성에 미치는 영향)

  • 김병철;김승규
    • The Korean Journal of Rheology
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    • v.11 no.1
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    • pp.28-33
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    • 1999
  • Introducing boric acid to the polyviny alcohol(PVA) solutions has a profound effect on the rheological properties through crosslinking between hydroxyl groups of PVA. This study investigates the effect of boric acid on the rheological properties of polyvinyl alcohol(PVA)/dimethyl sulfoxide(DMSO)/water systems in the absence of cations. The viscosity of PVA/ DMSO/water systems containing 1 wt.% boric acid was decreased with increasing water content. PVA/DMSO systems containing 1 wt.% boric acid exhibited rheological properties similar to elastic gels by forming crosslinked structures. On the other hand, PVA/water systems containing 1 wt.% boric acid exhibited rheological properties typical of viscous materials. In-corporation of boric acid into PVA/DMSO system caused a notable change in the viscosity of the system, whereas boric acid had little effect on the viscosity of PVA/water system. PVA/DMSO/boric acid system gave the greatest storage modulus among the PVA solution systems. Increasing water level in the mixed solvent of DMSO and water diminished the storage modulus of the systems.

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Cloning of Notl-linked DNA Detected by Restriction Landmark Genomic Scanning of Human Genome

  • Kim Jeong-Hwan;Lee Kyung-Tae;Kim Hyung-Chul;Yang Jin-Ok;Hahn Yoon-Soo;Kim Sang-Soo;Kim Seon-Young;Yoo Hyang-Sook;Kim Yong-Sung
    • Genomics & Informatics
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    • v.4 no.1
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    • pp.1-10
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    • 2006
  • Epigenetic alterations are common features of human solid tumors, though global DNA methylation has been difficult to assess. Restriction Landmark Genomic Scanning (RLGS) is one of technology to examine epigenetic alterations at several thousand Notl sites of promoter regions in tumor genome. To assess sequence information for Notl sequences in RLGS gel, we cloned 1,161 unique Notl-linked clones, compromising about 60% of the spots in the soluble region of RLGS profile, and performed BLAT searches on the UCSC genome server, May 2004 Freeze. 1,023 (88%) unique sequences were matched to the CpG islands of human genome showing a large bias of RLGS toward identifying potential genes or CpG islands. The cloned Notl-loci had a high frequency (71%) of occurrence within CpG islands near the 5' ends of known genes rather than within CpG islands near the 3' ends or intragenic regions, making RLGS a potent tool for the identification of gene-associated methylation events. By mixing RLGS gels with all Notl-linked clones, we addressed 151 Notl sequences onto a standard RLGS gel and compared them with previous reports from several types of tumors. We hope our sequence information will be useful to identify novel epigenetic targets in any types of tumor genome.