• Journal of Integrative Natural Science
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• v.2 no.1
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• pp.28-31
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• 2009

We describe the synthesis and characterization of silicon nanoparticles prepared by the soluton reduction of SiCl4. These reactions produce Si nanoparticles with surfaces that are covalently terminated. The resultant organic derivatized Si nanoparticles as well as a probable distribution of Water-soluble Si nanoparticles are observed and characterized by photoluminescence(PL) spectroscopy. This work focuses originally on the organic- and water-soluble silicon nanoparticles in terms of the photoluminescence. Further this work displays probably the first layout of hydrogen terminated Si nanoparticles synthesized in solution at room temperature.

• Korean Journal of Materials Research
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• v.30 no.2
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• pp.93-98
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• 2020

Effective control of the heat generated from electronics and semiconductor devices requires a high thermal conductivity and a low thermal expansion coefficient appropriate for devices or modules. A method of reducing the thermal expansion coefficient of Cu has been suggested wherein a ceramic filler having a low thermal expansion coefficient is applied to Cu, which has high thermal conductivity. In this study, using pressureless sintering rather than costly pressure sintering, a polymer solution synthesis method was used to make nano-sized Cu powder for application to Cu matrix with an AlN filler. Due to the low sinterability, the sintered Cu prepared from commercial Cu powder included large pores inside the sintered bodies. A sintered Cu body with Zn, as a liquid phase sintering agent, was prepared by the polymer solution synthesis method for exclusion of pores, which affect thermal conductivity and thermal expansion. The pressureless sintered Cu bodies including Zn showed higher thermal conductivity (180 W/m·K) and lower thermal expansion coefficient (15.8×10^-6/℃) than did the monolithic synthesized Cu sintered body.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2256-2260
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• 2013

A new quinoline-based acylhydrazone (1) has been synthesized and applied as a fluorescent probe. Probe 1 exhibits high selectivity and sensitivity to $Cu^{2+}$ with fluorescence "ON-OFF" behavior in HEPES buffered (1‰ DMSO, HEPES 20 mM, pH = 7.4) solution. The on-site generated 1-$Cu^{2+}$ complex displays excellent selectivity to sulfide ions with fluorescence "OFF-ON" performance through copper displacement approach.

• Resources Recycling
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• v.18 no.4
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• pp.38-43
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• 2009

The synthesis of aluminum oxalate, one of the aluminum organic compounds, has been performed using aluminum hydroxide as a raw material. For this aim, domestic aluminum hydroxide of 99.7% purity was dissolved by oxalic acid to produce an aqueous aluminum solution. As a result, it was found that aluminum hydroxide could be dissolved almost completely by the reaction with 1.0 mole/l oxalic acid solution at $90^{\circ}C$ for 16 hr. It was strongly required to keep the ratio of ethanol/Al solution more than 2.0 for the synthesis of aluminum oxalate from the aluminum solution. Furthermore, the pH should be controlled to be more than 8.2 in order to obtain the recovery of aluminum oxalate higher than 90%. From the chemical analysis of aluminum oxalate prepared in this work, the content of $NH_4$, Al and C was found to be 14.5, 7.18 and 17.4%, respectively. Accordingly, the aluminum oxalate synthesized from the aluminum solution was confirmed to be $(NH_4)_3Al(C_2O_4)_3$ $3H_2O$.

• Resources Recycling
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• v.20 no.2
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• pp.54-59
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• 2011

An investigation on the synthesis of aluminum tartrate, one of the aluminum organic compounds, has been performed using aluminum chloride solution as a raw material. For this aim, the effect of the ratio of ethanol/Al solution and pH on the synthesis of aluminum tartrate has been examined and aluminum tartrate synthesized has also been characterized in terms of the chemical composition, X-ray diffraction pattern, particle size distribution, and SEM analysis. As a result, the synthesis more than 97% could be obtained under the conditions of pH more than 3.0 at the ratio of ethanol/Al solution of 3.0. From the chemical analysis of aluminum tartrate synthesized in this work, the content of $NH_4$, Al and C was found to be 9.10, 4.83 and 25.8%, respectively. In addition, aluminum tartrate synthesized from the aluminum chloride solution was found to be $(NH_4)_3Al(C_4H_4O_6)_3$.

• YAKHAK HOEJI
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• v.44 no.6
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• pp.545-551
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• 2000

Magnesium trisilicate was prepared by reacting Magnesium sulfate solution with Sodium silicate solution in this study. The optimum synthesis conditions base on the yield of the product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of Magnesium trisilicate were as follows; Reacting temperature : $57{\sim}90^{\circ}C$, Concentration of reactant solution : $19.1{\sim}20.0%$, Molar concentration ratio of two reactants : [Sod.silicate]/[Mg.sulfate] : $1.47{\sim}1.80$, Temperature of washing water : $45{\sim}48^{\circ}C$, Drying temperature : $65{\sim}82^{\circ}C$. The antacidic capacity of the five Magnesium trisilicate samples which shows the maximum antacidic efficacy was tested by pharmacopeia acid consuming capacity test. The five Magnesium trisilicate samples were identified by chemical analysis.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.3
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• pp.88-98
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• 1998

In many automatization applications, a rigid body is required to go forward and backward repeatedly through a set of given position/orientations precisely while a crank is rotated. Such a motion can be generated by 6 bar mechanism adding a dyad to a 4 bar mechanism. If this is the case for 3 position synthesis of the 4 bar mechanism, the feasible solution area for designing the 4 bar mechanism will be limited over the general solution area. This paper proposes a procedure to synthesize 4 bar mechanism to be used to generate the required motion. It is found that the only input crank of the 4 bar mechanism should be limited to satisfy the condition. And the feasible design area for the circle point/ center point of the input crank is identified so that design of the undesired mechanism could be avoided. The method is tested and the results are shown.

• Journal of the Korean Ceramic Society
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• v.34 no.7
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• pp.731-737
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• 1997

TixZr1-xC(0$0^{\circ}C$, 5.1 mm/sec respectively. The relative density, three point flexural strength, and the hardness of composites, which was sintered at 190$0^{\circ}C$ for 60 min by using hot-pressing under a pressure of 30 MPa, were 99%, 525 MPa and 24 GPa respectively.

• Environmental Engineering Research
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• v.10 no.4
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• pp.165-173
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• 2005

Nano-sized iron particles were synthesized by reduction of $Fe^{3+}$ in aqueous solution under two reaction conditions, aerobic and anaerobic, and the reactivity of iron was tested by reaction with trichloroethene (TCE) using a batch system. Results showed that iron produced under anoxic condition for both synthesis and drying steps gave rise to iron with higher reduction reactivity, indicating the presence of oxygen is not favorable for production of nano-sized iron deemed to accomplish reactivity enhancement from particle sized reduction. Nano-sized iron sample obtained from the anoxic synthesis condition was further characterized using various instrumental measurements to identity particle morphology, composition, surface area, and particle size distribution. The scanning electron microscopic (SEM) image showed that synthesized particles were uniform, spherical particles (< 100 nm), and aggregated into various chain structures. The effects of other synthesis conditions such as solution pH, initial $Fe^{3+}$ concentration, and reductant injection rate on the reactivity of nano-sized iron, along with standardization of the synthesis protocol, are presented in the companion paper.

• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.25-30
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• 2005

The 4-bar linkage is the simplest model for the simulation of a retractable landing gear. In general, a designer uses a commercial software to design a linkage, which requires tedious iterations to obtain a good solution. By applying synthesis methodology the iteration process can be reduced remarkably. However, most of solutions obtained using synthesis process may not be an optimized solution. In this study, the characteristics of the optimization solution domain has been analyzed so that an optimization process can be adapted easily to a synthesis process.