• Korean Journal of Rural Living Science
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• v.7 no.2
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• pp.121-128
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• 1996

This study was performed to define the effects of Far Infrared Ray Radiation Fabrics as summer garments during outdoor work by human trial. One healthy male subject was volunteered for this study. Experimental garments consisted of three kinds of trousers (Cotton, Cotton/linen blended, Far Infrared Ray Radiation Fabric/wool blended) and basic garments (panty, socks, shirts, and dress shirts). The measurements were rectal temp., skin temp., microclimate inside clothing, heart rate, subjective sensation etc. The results were as follows : 1. Rectal temperature showed the lowest in Far Infrared Ray Radiation Fabrics among 3 garments. 2. Skin temperature (forehead, chest abdomen temp.) and mean skin temperature were lower in Far Infrared Ray Radiation Fabrics than in others, especially during early stage of work. 3. Heart rate showed lower value in Far Infrared Ray Radiation Fabrics than in others but there was no significance among the garments. 4. Humidity inside clothing and total weight loss showed the highest value in Far Infrared Ray Radiation Fabrics.

• Computers and Concrete
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• v.29 no.4
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• pp.237-246
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• 2022

The concrete quality relies on general factors like preparation technique, uniformity of the compaction, amount and appropriateness of the additives. The current article investigates the impact of a well knows amino acid, L-arginine as an additive on water requirements, setting durations and characterization of various cement samples. Compressive strength tests of reference and L-arginine added cements at age of 2, 7 and 28 days were carried out according to TS-EN 196-1. Samples were blended by incorporating various amounts of L-arginine (25 ppm, 50 ppm and 75 ppm) in the cement water mixture which were tested with Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TG), scanning electron microscopy (SEM) and the energy-dispersive X-ray spectroscopy (EDS) on the 28th day. Results revealed that L-arginine does not affect the setting time, volume expansion of cement and water demands negatively; rather it imparts enhanced sustainability to the samples. It was determined that the highest value belonged to the 75L mortar with an increase of 2.6% compared to the reference sample when the compressive strengths of all mortars were compared on the 28th day. Besides, it has been observed that the development of calcium silicate hydrate or C-S-H gel, calcium hydroxide or CH and other hydrated products are associated with each other. L-arginine definitely has a contribution in the consumption of CH formed in the hydration process.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1310-1314
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• 2011

Sodium beta-alumina (SBA) nano-powders were synthesized by the citrate sol-gel process, and the effects of the cationic surfactant n-cetyltrimethylammonium bromide surfactant (CTAB) were investigated. The structure and morphology of the nano-powders were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM) techniques, respectively. The effects of CTAB on the citrate sol-gel process and the SBA formation were investigated by thermo gravimetric/differential thermal analysis (TG/DTA) and Fourier transform infrared spectroscopy (FTIR). The conductivity of ceramic pellets of SBA was measured by electrochemical impedance spectroscopy (EIS). The results showed that the CTAB inhibited the agglomeration of SBA powders effectively and consequently decreased the crystallization temperature of SBA, about $150^{\circ}C$ lower than that of the sample without CTAB. The measured conductivity of SBA was $1.21{\times}10^{-2}S{\cdot}cm^{-1}$ at $300^{\circ}C$.

• Journal of Environmental Science International
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• v.24 no.9
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• pp.1145-1153
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• 2015

PVC-Zeolite composite was prepared by immobilizing zeolite with polyvinyl chloride (PVC). The prepared PVC-Zeolite beads were characterized by using X-ray diffractometer (XRD), fourier transform infrared spectrometer (FTIR), thermo gravimetric analyzer (TGA), and scanning electron microscopy (SEM). The removal properties of Sr and Cs ions from aqueous solution were investigated in batch experiment. The removal efficiencies of Sr and Cs ions by the PVC-Zeolite beads were dependent on the initial pH of solution. The removal efficiencies sharply increased at below pH 4 and was kept constant at pH 4 or more. The adsorption kinetics of Sr and Cs ions by the PVC-Zeolite beads were fitted well by the pseudo-second-order model ($r^2$>0.99) more than pseudo-first-order model. The maximum adsorption capacities of Sr and Cs ions calculated from Langmuir isotherm model were 39.37 mg/g and 55.87 mg/g, respectively.

• Journal of Magnetics
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• v.18 no.4
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• pp.391-394
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• 2013

In this study, nickel-zinc ferrite nanoparticles, with the chemical formula of $Ni_{0.3}Zn_{0.7-x}Cu_xFe_2O_4$ (where x = 0.1- 0.6 by step 0.1), were fabricated by the sol-gel method. The effect of copper substitution on the phase formation and crystal structure of the sample was investigated by X-ray diffraction (XRD), thermo-gravimetry (TG), differential thermal analysis (DTA), Fourier transform infrared spectrometry (FT-IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD result shows that due to the reduction of Zn content,the crystallite size of the sample increased. The results of the vibration sample magnetometer (VSM) exhibit an increase in saturation magnetization value (Ms) for samples with x ${\leq}$ 0.3 and a linear decrease for samples with x > 0.3. The variation of saturation magnetization and coercivity of the samples were then studied.

• Advances in materials Research
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• v.11 no.3
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• pp.191-209
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• 2022

Very slow degradation of synthetic based polymers has created a severe environmental issue that increased awareness towards research in polymers of biodegradable property. Soy protein isolate (SPI) is a natural biopolymer used as matrix in green composites but it has limitations of low mechanical properties and high water sensitivity. To enhance mechanical properties and reduce water sensitivity of Jute-SPI composites, SPI was modified with pine rosin which is also a natural cross-linking agent. 30% glycerol on the weight basis of a matrix was used as a plasticizer. The fibre volume fraction was kept constant at 0.2 whereas the pine rosin in SPI ranged from 5% to 30% of the matrix. The effects of pine rosin on mechanical, thermal, water sensitivity and surface morphology have been characterized using various techniques. The mechanical properties and water absorbency were found to be optimum for 15% pine rosin in Jute-SPI composite. Therefore, Jute-SPI composite without pine rosin and with 15% pine rosin were chosen for investigation through characterization by Fourier transforms infrared spectroscopy (FTIR), Thermo-gravimetric analysis (TGA), X-Ray diffraction (XRD) and Scanning electron microscope (SEM). The surface morphology of the composite was influenced by pine rosin which is shown in the SEM image. TGA measurement showed that the thermal properties improved due to the addition of pine rosin. Antimicrobial test showed antimicrobial property in the composite occurring 15% pine rosin. The research paper concludes that the modification of SPI resin with an optimum percentage of pine rosin enhanced mechanical, thermal as well as water-resistant properties of jute fibre reinforced composites.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.3
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• pp.307-315
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• 2023

The physical and chemical changes exhibited by high density polyethylene (HDPE) after treatment with hydrogen at a pressure of 90 MPa followed by rapid release of the hydrogen were studied. X-ray diffraction, differential scanning calorimetry, thermo gravimetric analysis, and attenuated total reflectance (ATR)-fourier transform infrared (FTIR) were used for this purpose. As a result, it was found that the degree of crystallinity of HDPE decreased after hydrogen pressure treatment, while the average thickness of lamellae that constitute the crystals and the melting temperature of the crystalline region actually increased. The decomposition temperature also increased by about 3℃. In addition, it was found that the hydrogen bonding network between -OH groups in the HDPE sample was strengthened and partial chain scission occurred. These cut chains were found to be terminated by oxidative degradation such as cross-linking between chains, -C=O, -C-O, and -CHO, or by the formation of -CH₃ at the chain ends, as confirmed by ATR-FTIR.

• Journal of Conservation Science
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• v.18 s.18
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• pp.51-62
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• 2006

This study, in order to do a nondestructive research on the mural walls kept in the protective house in Muwisa Temple, Kangjin, took four examinations; particle size analysis, XRD analysis, ultrasonic investigation, and thermo-infrared investigation. Component ratio of mural wall varied; clay of wall bodies consisted of gravel of 1.78 g, sand of 5.39 g, silt of 4.91 g and clay of 6.26 g. Ultrasonic velocity and one-axis compression strength tests done with eight mural-painted walls yield results as follows; the value of ultrasonic velocity ranged between 71.63 and 3610.11 m/s with the average of 417.44 m/s and on-axis compression strength ranged between 70.34 and $533.28kg/cm^2$ with the average of $83.23kg/cm^2$. The value increased in the order of Bosaldo(No.6)

• Korean Journal of Materials Research
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• v.22 no.6
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• pp.275-279
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• 2012

(3-mercaptopropyl)trimethoxysilane (MPTMS) was used as a silylation agent, and modified silica nanoparticles were prepared by solution polymerization. 2.0 g of silica nanoparticles, 150 ml of toluene, and 20 ml of MPTMS were put into a 300 ml flask, and these mixtures were dispersed with ultrasonic vibration for 60 min. 0.2 g of hydroquinone as an inhibitor and 1 to 2 drops of 2,6-dimethylpyridine as a catalyst were added into the mixture. The mixture was then stirred with a magnetic stirrer for 8 hrs. at room temperature. After the reaction, the mixture was centrifuged for 1 hr. at 6000rpm. After precipitation, 150 ml of ethanol was added, and ultrasonic vibration was applied for 30 min. After the ultrasonic vibration, centrifugation was carried out again for 1 hr. at 6000rpm. Organo-modification of silica nanoparticles with a ${\gamma}$-methacryloxypropyl functional group was successfully achieved by solution polymerization in the ethanol solution. The characteristics of the ${\gamma}$-mercaptopropyl modified silica nanoparticles (MPSN) were examined using X-ray photoelectron spectroscopy (XPS, THERMO VG SCIENTIFIC, MultiLab 2000), a laser scattering system (LSS, TOPCON Co., GLS-1000), Fourier transform infrared spectroscopy (FTIR, JASCO INTERNATIONL CO., FT/IR-4200), scanning electron microscopy (SEM, HITACHI, S-2400), an elemental analysis (EA, Elementar, Vario macro/micro) and a thermogravimetric analysis (TGA, Perkin Elmer, TGA 7, Pyris 1). From the analysis results, the content of the methacryloxypropyl group was 0.98 mmol/g and the conversion rate of acrylamide monomer was 93%. SEM analysis results showed that the organo-modification of ultra-fine particles effectively prevented their agglomeration and improved their dispensability.

• Journal of the Korean Ceramic Society
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• v.48 no.1
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• pp.63-68
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• 2011

The investigation is directed to lead free (Pb-free) frits that can be used for organic light emitting diode, plasma display screen devices and other sealing materials. $P_2O_5$-SnO system glasses have been prepared for Pb-free low temperature glass frit. Structure and properties of the glasses with the composition SnO-$xB_2O_3-(60-x)P_2O_5$ (x=0, 5, 10, 15, 20, 25, 30, 35, 40 mol%) were characterized by infrared spectra (IR), X-ray diffraction(XRD), Density, Molar volume, Thermo mechanical analysis(TMA) and weight loss after immersion test. Glass transition temperature($T_g$), dilatometric softening temperature($T_d$) and chemical durability increased, and coefficient of thermal expansion($\alpha$) decrease with the substitution of $B_2O_3$ for $P_2O_5$ in the range of 0~25 mol%.