• Food Science of Animal Resources
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• v.33 no.4
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• pp.474-480
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• 2013

This study was performed to investigate the effects of high pressure/high temperature (HPHT) treatment on the recovery efficiency and characteristics of porcine placenta hydrolysates. The placenta hydrolysates were characterized by solubility, free amino acid contents, gel electrophoresis, gel permeation chromatography (GPC) and amino acid composition. Placenta was treated at 37.5 MPa of pressure combined with various temperatures (150, 170, and $200^{\circ}C$) or various holding times (0, 30, and 60 min at $170^{\circ}C$). Insoluble raw placenta collagen was partially solubilized (> 60% solubility) by the HPHT treatment. Free amino group content of placenta collagen was increased from 0.1 mM/g collagen to > 0.3 mM/g collagen after HPHT treatment, reflecting partial hydrolysis of collagen. The molecular weight ($M_w$) distribution showed evidence of collagen hydrolysis by shifting of $M_w$ peaks toward low molecular weight when treated temperature or holding time was increased. Alanine (Ala), glycine (Gly), hydroxyproline (Hyp), and proline (Pro) contents increased after the HPHT treatments compared to a decrease in the others. In particular, the increase in Gly was obvious, followed by Hyp and Pro, reflecting that placenta hydrolysates were mainly composed of these amino acids. However, increasing temperature or holding time hardly affected the amino acid compositions. These results indicate that the HPHT treatment is advantageous to hydrolyze collagen derived from animal by-products.

• Journal of Biomedical Engineering Research
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• v.40 no.1
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• pp.7-14
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• 2019

The microencapsulation of nifedipine (NF) with 4 wt% of poly(${\varepsilon}-caprolactone$) (PCL)/polyvinylpyrollidone (PVP) or PCL/polyethylene glycol (PEG) was carried out by solvent evaporation method in oil in water emulsion system to investigate the effect of PVP and PEG addition on drug release behavior of the microcapsules. The PVA (emulsifier) concentration of 1.0 wt% was chosen for the formation of PCL capsule having an average size of $154{\pm}25{\mu}m$ due to nearly spherical shape with a narrow size distribution. As PCL/PVP and PCL/PEG ratios were raised from 10/0 to 6/4, the capsule size increased gradually from $154{\pm}25{\mu}m$ to $236{\pm}32{\mu}m$ and $248{\pm}56{\mu}m$, respectively. The drug release rate of PCL/PVP and PCL/PEG capsules increased dramatically from 0 to 4 h at the beginning and then reached the plateau region from 20 h. As the concentration of PVP or PEG increased, the amount of drug release increased, suggesting that the larger capsule size was attributed to the higher drug content. However, the drug release behavior remained almost constant. The PCL capsules exhibited no evidence of causing cell lysis or toxicity regardless of NF loading, implying that the microcapsules are clinically suitable for use as drug delivery systems.

• Journal of the Korean GEO-environmental Society
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• v.4 no.4
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• pp.17-23
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• 2003

Accurate prediction of consolidation behaviors of the soft ground improved by plastic board drains is not easy because the consolidation characteristics of the improved ground has not been fully elucidated yet. The shape of drains is one of the most important factors which affect the consolidation characteristics of the improved ground. In this paper, a series of model consolidation tests of soft clay ground improved by plastic board drain were carried out, in order to investigate the effect of both plastic board width and stress level on consolidation characteristics of the improved ground. As the results, behaviors of both settlement and excess pore pressure dissipation were elucidated. Also, the non-uniform distribution of water content in the model ground was obtained. Then, in order to investigate the effect of vertical drainage on the consolidation behavior in the model tests, the comparison between experimental consolidation behaviors and Barron's theoretical ones were carried out. As the results, it was elucidated that the consolidation behavior in the model tests was affected not only by radial drainage but also by vertical drainage.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.365-370
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• 2006

This study was performed to determine the adsorption-desorption characteristics of polyhexame-thyleneguanidine phosphate in three different soil types of textural classification. Adsorption and desorption studies is impotent for prediction their fate and generating essential information on the mobility of chemicals and their distribution in the soil, water and air of our biosphere. The detection limit of the test substance quantified by a spectroscopic method using Eosin indicator was $0.25{\mu}g/mL$. The reproducibility of analytical method was confirmed by the preliminary test. The concentrations of polyhexamethylenequanidine phosphate in aqueous solution were $1.36{\pm}0.09,\;2.45{\pm}0.01,\;and\;$4.25{\pm}0.05{\mu}g/mL$ by a spectroscopic method using Eosin indicator. The adsorption percents of polyhexamethylenequanidine phosphate in soil were greater than 95.2% for all three test soils. The desorption percents from the adsorbed soil were less than 4.5, 4.7 and 4.7%. Therefore, the adsorption coefficient (K) were greater than 110, 111 and 116. The adsorption coefficient calculated as a function of the organic carbon content (Koc) of the test soils were greater than 9,181, 11,100, and 8,942, respectively. Therefore, the test substance, polyhexamethylenequanidine phosphate could be concluded as medium or high adsorption (>25%) and poorly desorption (<75%) in soil media. Therefore, this chemical is likely to be retained in soil media and may not pose a risk in the aquatic environment.

• Journal of Pharmacopuncture
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• v.20 no.1
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• pp.36-44
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• 2017

Objectives: The goal of this study was to characterize Suvarna Bhasma Parada Marit by using the Ayurvedic test parameters, physico-chemical tests, and various instrumentation techniques. Methods: Suvarna Bhasma, an Ayurvedic formulation manufactured as per Bharat Bhaishajya Ratnakar 5/8357 (BBR), has been studied using various instrumentation techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), laser particle size distribution (PSD) analysis, fourier transform infrared spectroscopy (FT-IR), and atomic absorption spectroscopy (AAS), and physico-chemical parameters, such as the loss on drying (LOD), loss on ignition (LOI), and acid insoluble Ash (AIA) were determined. In addition, Ayurvedic tests, such as Rekhapurnatva (enterable in the furrows of the fingers), Varitaratwa (floatable over water), Nirdhoomta (smokeless), Dantagre Kach-Kach (gritty particle feeling between the teeth), were performed. Results: The XRD study showed Suvarna Bhasma to be crystalline in nature and to contain more than 98% gold. The mean size of the gold crystallites was less than 10 microns, and the morphology was globular and irregular. Suvarna Bhasma contains gold as its single and major element, with EDAX and FT-IR spectra showing that it is more than 98% pure gold. The moisture content (LOD) is less than 0.5%, the LOI is less than 2%, and the AIA is not less than 95%. The Ayurvedic tests, as specified above, helped to confirm the quality of Suvarna bhasma prepared as per the text reference (BBR). Conclusion: This chemical characterization of Suvarna Bhasma performed in this study by using modern instrumentation techniques will be helpful in understanding its pharmacological actions and will help in establishing quality protocols and specifications to substantiate the safety, efficacy & quality of Suvarna Bhasma.

• Journal of the Korean Society of Food Science and Nutrition
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• v.7 no.1
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• pp.15-18
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• 1978

For a general ingredients analysis and E Coli-form bacteria surveyed on the marketed milk, samples of bottled milk produced by four different companies were collected in Cholla Buk-do area and examined. The results are: 1) In water content samples A and C exceeded the standard slightly whereas B and D were good. 2) The contents of crude fat and crude protein of all samples were slightly higher than the standard. 3) All samples were deficient in contents of the crude ash and lactose. 4) In spite of the winter, all samples contained more coli-form bacteria than the standard allowance. Through the above results, it could be seen that all samples of marketed milk were a little poor in the contents of general ingredients and contained more coli-form bacteria than the standard allowances. Therefore, considering the general trends of increasing milk consumption and its influence on the national public health. it is necessary for the milk manufacturer to try to streng hen the scientific inspection and improve, the handling of milk products during the distribution.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.1
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• pp.173-178
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• 1993

The most appropriate mixing ratio of fly ash to bottom ash obtained from compaction characteristics and CBR values is varying from 5:5 to 6:4. But these mixed ashes are frost-susceptible materials according to judging by the paticle-size distribution because of a lot of silty-size paticles. In this study, the frost-susceptibility of compacted coal ash with proper mixing ratio is examined experimentally for use of subgrade materials. And, the efforts have been made to find proper cement addition in making these mixed ashes frost-insusceptible. It was revealed that these mixed ashes are frost-susceptible, and 4% of cement content is required to be made frost-insusceptable. It was found that amount of frost heave of these mixed ashes decreases with the unconfined compressive strength, and increases with log k if the permeability coefficient k is as low as the water into the freezing front of these mixed ashes is restricted.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.136-144
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• 1996

Polyacrylic super absorbent polymer(SAP) containing sorbitol was synthesized by inverse-suspension polymerization method. Sodium acrylate and acrylic acid were used as a monomer, ethylene glycol dimethacrylate(EGDMA) and glycerol polyglycidyl ether(GPGE) were used as a crosslinking agent, potassium persulfate(PPS) was used as an initiator, and cyclohexane was used as a solvent. Content of sorbitol was from 10mol% to 50mol% according to the mol ratio of acrylic acid monomer. The size distribution of the round shaped polymeric particle was $177{\sim}707{\mu}m$. Absorption amount of the polymer containing sorbitol was 785 to 1086 times of the polymer weight in distilled water, was 50 to 83 times in 0.9 % NaCl solution. Absorption and retention amount of the polymer were decreased with increasing the amount of sorbitol, but the polymer has an endothermic property which is +5 cal/g SAP.

• Korean Journal of Materials Research
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• v.34 no.1
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• pp.44-54
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• 2024

High-Manganese (Mn) austenitic steel, with over 24 wt% Mn content, offers outstanding mechanical properties in cryogenic settings, making it a potential replacement for existing cryogenic materials. This high manganese steel exhibits high strength, ductility, and wear resistance, making it promising for applications like LNG tanks, flanges, and valves. To operate in cryogenic environments, hot forging and heat treatment processes are vital, especially in flange production. The cooling rate during high-temperature cooling after hot forging plays a critical role in influencing the microstructure and mechanical properties of high manganese steel. The rate at which cooling occurs during this process influences the size of the grains and the distribution of manganese and consequently has an impact on mechanical properties. This study assessed the microstructure and mechanical properties based on different cooling rates during the hot forging of High-Mn steel flanges. Comparing air and water cooling after hot forging, followed by heat treatment, revealed notable differences in grain size. These differences directly impacted mechanical properties such as tensile strength, hardness, and Charpy impact property. Understanding these effects is crucial for optimizing the performance and reliability of High-Mn steel in cryogenic applications.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.2
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• pp.145-154
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• 1990

Amounts of total suspended matter(TSM) around the Kori waters have been monitored for two years to understand the dispersal pattern of fine-grained sediment. Average concentration of the TSM is $3\~4\;mg/\iota$ in the surface and $3.5\~5\;mg/\iota$ in the near-bottom water. Semi-quantitative analysis for the four major clay minerals in TSM is also performed. The average relative abundance of each clay mineral such as illite, kaolinite, chlorite, and smectite is $65\%,\;17\%,\;17\%$, and $1\%$, respectively. It seems that the majority of recent fine-grained sediment deposited around the Kori area is derived from the Nakdong River. The texture of surface sediment is also dominated by fine-grained fraction leading up to $90\%$ of silt and clay content. The grain size decreases seaward progressively.