• The Korean Journal of Food And Nutrition
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• v.13 no.6
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• pp.521-528
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• 2000

Conditions for processing dried condiments with powdered sea tangle were investigated. The most appropriate method for sea tangle extraction was two-stage extraction, that extracted with addition of 70% ethyl alcohol at $25^{\circ}C$ for 1 hour and residue was re-extracted with water(1:15, w/w) at 7$0^{\circ}C$ for 3 hours. The yield of soluble solids under above-mentioned conditions was 14.9%. As a result of omission tests, free amino acids were predominated in the taste compounds of sea tangle extracts rather than nucleotides, and the contribution of free amino acids and nucleotides to the taste of sea tangle extracts was remarkable. The major flavoring components of sea tangle extracts were matters of low molecular weight such as free amino acids and oligopeptides below 5,700 dalton. Contents of carbohydrate, total nitrogen and amino nitrogen in dried condiments prepared with sea tangle extracts were 64.9%, 3.7% and 2.1%, respectively. And drying yield, solubility and absorption rates at Aw 0.88 were 14.7%, 98.3% and 8.4%, respectively.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.1
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• pp.209-224
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• 1998

The purpose of this study was to compare the amount of calcium fluoride deposited on the enamel and dentin surface and to obtain information on the morphological change and crystallographic details of mineral deposition after 12,000ppm APF application in vitro. The bovine enamel and dentin blocks were randomly assigned to eight groups according to artificial caries lesion formation and difference of fluoride application time. The fluoride concentration and morphological characteristics on the treated enamel and dentin surface were investigated by using fluoride quantitative analysis and SEM. The powdered enamel and dentin of the intact bovine incisors were prepared for the X-ray diffraction analysis. The following results were obtained. 1. The amounts of KOH-soluble fluoride on the carious enamel and dentin surface after 24h APF application were higher than after only 5min APF application(p<0.05), but in the case of the sound enamel and dentin surface were similar after 5min and 24h application (P>0.05). The fluoride content was highly increased in the carious dentin as compared with sound dentin after APF application(P<0.05). 2. The carious enamel surface after APF application, the demineralized enamel surface were recovered a more dense enamel surface and precipitation of crystal was observed a distintive surface layer of spherical globules of about 1 m diameter. In the case of the fluorided carious dentin surface, precipitation of calcium fluoride-like material was deposited both inside the dentinal tubules as well as in the intertubular regions. 3. The crystallographic structure of powdered enamel and dentin after 24h APF application had large crystallities of apatite and CaF2 diffraction peaks in the enamel as compared with dentin. The diffraction data collected from the 27.50-29.50(2) angular range of the powdered enamel, the (105) apatite, (225) apatite and (111) CaF2 peaks of the enamel crystallities were detected after 24h APF application.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.516-524
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• 2012

Selective Laser Sintering(SLS) system consists of various element technologies. Main components of the system include a position control system, a speed control system of the roller, and nitrogen atmosphere furtherance for the powdered sintering. Other systems which make the core of the SLS system are build room and the feed room for powder epitaxial, a temperature control system, and a scan path generator for the laser. The powder material for laser sintering is necessary to produce prototypes in Solid Freeform Fabrication(SFF) based on SLS process. This powder material is sintered in powder room using $CO_2$ laser after spreading evenly using roller to reproduce mold via SFF. This study addresses an SFF system by using the SLS process which applies single laser system to enable manufacturing of 3D shape. And to evaluate applicability of the single laser system, experiments were conducted with optimal fabricating process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.405-406
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• 2005

A theoretical investigation of the solid-phase mechanochemical synthesis of nano-sized target product on the basis of dilution of the initial powdered reagent mixture by another product of an exchange reaction is presented. On the basis of the proposed 3-mode particle size distribution in mechanically activated mixture, optimal molar ratios of the components in mixture are calculated, providing the occurrence of impact-friction contacts of reagent particles and excluding aggregation of the nanosized particles of the target reaction product. Derivation of kinetic equations for mechanochemical synthesis of nanoscale particles by the final product dilution method in the systems of exchange reactions is submitted. On the basis of obtained equations the necessary times of mechanical activation for complete course of mechanochemical reactions are designed. Kinetics of solid phase mechanosynthesis of nano-TlCl by dilution of initial (2NaCl + $Tl_2SO_4$) mixture with the exchange reaction product (diluent, $zNa_2SO_4$, $z=z^*=11.25$) was studied experimentally. Some peculiar features of the reaction mechanism were found. Parameters of the kinetic curve of nano-TlCl obtained experimentally were compared with those for the model reaction KBr + TlCl + zKCl = (z + 1) KCl + TlBr ($z=z_l^*=13.5$), and for the first time the value of mass transfer coefficient in a mechanochemical reactor with mobile milling balls was evaluated. Dynamics of the size change was followed for nanoparticle reaction product as a function of mechanical activation time.

• Membrane and Water Treatment
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• v.13 no.6
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• pp.321-335
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• 2022

Copper-based Metal-organic framework (MOF) namely ([Cu (INA)₂]-MOF) is synthesized by ball milling and characterized using scanning electron microscopy (SEM) for the topography, microstructure, and elemental evidence determination, powdered X-ray diffraction (XRD) for the crystallinity measurement, thermogravimetric (TG) analysis was performed to determine the thermal stability of the material, and Fourier transformed infrared (FTIR) spectroscopy for functional groups identification. The use of [Cu (INA)₂]-MOF as hazardous removal material of β-agonists as persistent hazardous micro-pollutants in our environmental water is first reported in this study. The removal efficiency of the Cu-MOF is successfully determined to be 97.7% within 40 minutes, and the MOF has established an exceptional removal capacity of 835 mg L^-1 with 95 % percent removal on Clenbuterol (CLB) even after the 5th consecutive cycle. The Langmuir model of the adsorption isotherms was shown to be more favourable, while the pseudo-second-order model was found to be favoured in the kinetics. The reaction was exothermic and spontaneous from a thermodynamic standpoint, and the higher temperatures were unfavourable for the adsorption study of the CLB. As a result, the studied MOF have shown promising properties as possible adsorbents for the removal of CLB in wastewater.

• Journal of Korean Port Research
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• v.14 no.3
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• pp.373-378
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• 2000

Oil spill in sea water is the most frequent and significant problem of marine pollution. As an early detection sensor of the pollution, an activated carbon coated quartz crystal is prepared and examined for its performance of detection sensitivity and stability. Powdered activated carbon and phenol resin is coated on the surface of the sensor and the sensor is baked for an hour. Adsorption of acetone dissolved in water and salt water is measured using frequency shift of quartz crystal at different concentrations of solute material. The outcome indicates that the sensor preparation is adequate and the measurement of solute concentration is stable and sensitive enough to be implemented on the monitoring of solute concentration is stable and sensitive enough to be implemented in the monitoring of organic pollution of sea water.

• Journal of the Korea Institute of Building Construction
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• v.7 no.1 s.23
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• pp.85-90
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• 2007

According as industry develops rapidly, problem of resources exhaustion and environmental pollution is appearing. Way to use construction waste that is development of new compound material and Industry product is required. Limestone powder that is Industry product is $CaCO_3$. and vicosity is promotion effect because there is no damage to hydration of cement and powder is very thin and water tightness increases. This research purposed to analyze concrete property changing limestone fineness. According as the limestone powdered replacement ratio increases, slump and unit capacity mass increased, and the air content decreased according as the replacement ratio increases. Compressive strength and tensile strength decreased according as the limestone powder replacement ratio increases.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.104-107
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• 2002

Direct Metal Manufacturing (DMM) is a new additive process that aims to take die making and metalworking in an entirely new direction. It is the blending of five common technologies : lasers, computer-aided design (CAD), computer-aided manufacturing (CAM), sensors and powder metallurgy. The resulting process creates parts by focusing an industrial laser beam onto a tool-steel work piece or platform to create a molten pool of metal. A small stream of powdered tool-steel metal is then injected into the melt pool to increase the size of the molten pool. By moving the laser beam back and forth, under CNC control, and tracing out a pattern determined by a computerized CAD design, the solid metal part is built line-by-line, one layer at a time. DMM produces improved material properties in less time and at a lower cast than is possible with traditional fabrication.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.349-352
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• 2001

Shape separation method - a separation process which utilizes the fact that particles of different shape behave differently in force fields- is regarded as an useful measure for recycling, mineral processing, upgrading powdered material and so on. In this study, a trial was given to shape separation method using fluid field to recover pure diatom skeleton - which is thought to have many uses in itself and potential for various applications -from low grade diatomaceous earth of southeastern part of the Korean Peninsula. The striking difference of shape between diatom skeleton and other minerals like clay and quartz made it natural to choose shape separation method. Considering the size of particles to be separated, among many possible methods of shape separation, hydrodynamic field using hydrocyclone was adopted. And it resulted in recovery of pure diatom skeleton with high purity

• CELLMED
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• v.3 no.1
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• pp.6.1-6.6
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• 2013

Asthma is a chronic inflammatory disease of the lungs, characterized by increased sensitivity to bronchoconstriction associated with infiltration of immune cells and mucus hyper secretion. In South Africa, the indigenous plant Siphonochilus aethiopicus, is used by traditional health practitioners to treat colds and flu, wheezing of the chest, coughs, influenza, sinus problems and mild asthma. In this study we aimed to investigate the potential anti-inflammatory and immune-modulating properties of S. aethiopicus in vitro. The dried and powdered S. aethiopicus plant material was extracted with organic solvents. The dried extracts were screened in vitro in the transcription response, NF-${\kappa}B$ and a cytokine assay. Significant activity was observed for organic extracts of the plant in these assays. This study provides evidence that S. aethiopicus has anti-inflammatory and immune-suppressing properties in vitro. These findings may support anecdotal accounts of its effectiveness against allergic asthma.