• Economic and Environmental Geology
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• v.57 no.4
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• pp.371-386
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• 2024

This paper presents analytical insights regarding into the occurrence of gold within organic matter, which is hosted by solid bitumen and closely associated with uranium ores in the Late Permian Kővágószőllős Sandstone Formation in Western Mecsek, South-West Hungary. The study utilizes a range of analytical techniques, including X-ray powder diffraction (XRPD) and wavelength dispersive X-ray fluorescence (WD-XRF) for comprehensive mineralogical and elemental analysis; organic petrography and electron microprobe analysis for characterizing organic matter; and an organic elemental analyzer for identifying organic compounds. A three-step sequential extraction method was used to liberate gold from organic matter and sulfide minerals, employing KOH, HCl, and aqua regia, followed by inductively coupled plasma optical emission spectroscopy (ICP-OES) to quantify gold contents. The organic matter is identified as comprising two vitrinite types (telinite V1 and reworked V2) and three solid bitumen forms: nonfluorescing (B1) and fluorescing (B2) fillings within the V1, as well as homogenous pyrobitumen (PB) occupying narrow cracks and voids within globular quartz. Despite the samples exhibiting low total organic carbon content (<1 wt%), they display high sulfur content (up to 6 wt%) and the sequentially extracted noble metal content from the organic matter is found to total 7.45 ppm gold. The research findings suggest that organic matter plays crucial roles in ore mineralization processes. Organic matter acts as an active component in the migration of gold, uranium, and hydrocarbons within sulfur-rich hydrothermal fluids. Additionally, organic matter contributes to the entrapment and enrichment of gold in hetero-atomic organic fractions, forming metal-organic compounds. Moreover, uranium inclusions are observed as oxide/phosphate minerals within solid bitumen and associated vitrinite particles. These insights into the occurrence and distribution of gold within organic matter highlight substantial exploration potential, guiding additional research activities focused on organic matter within the Kővágószőllős Sandstone Formation at the Western Mecsek deposit.

• Journal of the Korean Chemical Society
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• v.45 no.5
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• pp.461-469
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• 2001

The combinatorial approach has been applied to discover and optimize the composition of the novel or enhanced materials. In this study, we screened the optimum composition of the system SrO-Gd$_2$O$_3$-Al$_2$O$_3$ doped with $Tb^{3+}$ by a polymerized-complex combinatorial chemistry method. Mixtures with compositions of Sr, Gd and Al component that is in the range from 0 to 1 in about 0.05 increments could be tested. The sample powders were synthesized by a polymerized complex method. To prepare appropriately polymeric precursors, we used the metallic nitrates, citric acid and ethylene glycol. The luminescence properties of the synthesized powders are investigated using the UV and VUV (Vacuum-UV: 147 nm) photoluminescence spectrometer. In addition, the crystallinity and morphology of powder were monitored by X-ray diffraction spectrometer and scanning electron microscopy. In result of VUV PL works, there are good luminescent samples with the composition of 0.595 < x < 0.733 and 0.016 < y < 0.017 in Gd1-x-yAlxTbyO$\delta$ and 0.049 < x < 0.064 and 0.02 < y < 0.039 in $Sr_xAl_{1-x-y}Tb_yO_$\delta$$, their materials can be applicable to plasma display panels as the green phosphor.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.199-199
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• 2016

Commercially pure titanium (cp-Ti) and Ti alloys (typically Ti-6Al-4V) display excellent corrosion resistance and biocompatibility. Although the chemical composition and topography are considered important, the mechanical properties of the material and the loading conditions in the host have, conventionally. Ti and its alloys are not bioactive. Therefore, they do not chemically bond to the bone, whereas they physically bond with bone tissue. The electrochemical deposition process provides an effective surface for biocompatibility because large surface area can be served to cell proliferation. Electrochemical deposition method is an attractive technique for the deposition of hydroxyapatite (HAp). However, the adhesions of these coatings to the Ti surface needs to be improved for clinical used. Plasma electrolyte oxidation (PEO) enables control in the chemical com position, porous structure, and thickness of the $TiO_2$ layer on Ti surface. In addition, previous studies h ave concluded that the presence of $Ca^{+2}$ and ${PO_4}^{3-}$ ion coating on porous $TiO_2$ surface induced adhesion strength between HAp and Ti surface during electrochemical deposition. Silicon (Si) in particular has been found to be essential for normal bone and cartilage growth and development. Zinc (Zn) plays very important roles in bone formation and immune system regulation, and is also the most abundant trace element in bone. The objective of this work was to study electrochemical characteristcs of Zn and Si coating on Ti-6Al-4V by PEO treatment. The coating process involves two steps: 1) formation of porous $TiO_2$ on Ti-6Al-4V at high potential. A pulsed DC power supply was employed. 2) Electrochemical tests were carried out using potentiodynamic and AC impedance methoeds. The morphology, the chemical composition, and the micro-structure an alysis of the sample were examined using FE-SEM, EDS, and XRD. The enhancements of the HAp forming ability arise from $Si/Zn-TiO_2$ surface, which has formed the reduction of the Si/Zn ions. The promising results successfully demonstrate the immense potential of $Si/Zn-TiO_2$ coatings in dental and biomaterials applications.

• Journal of the Korean Chemical Society
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• v.43 no.6
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• pp.636-643
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• 1999

Green-emission intensity of a $Zn_{2-x}Mn_xSiO_4$ phosphor, which is a potential candidate as a green component in PDP device, significantly increases provided that the compound is additionally heat treated at 900$^{\circ}C$ after solid state reaction at 1300$^{\circ}C$. In order to verify origin of such an intensity enhancement after the additional heat treatment in association with the electronic and local structural change at around Mn ions, the Mn K-edge X-ray absorption spectra were recorded. From the analyses of the preedge peak corresponding to $1s{\rightarrow}3d$ bound state transition and XANES spectrum, it is known that most Mn ions are in +2 oxidation state and substitute Zn ion site regardless of the thermal treatment. In addition, EXAFS analyses revealed that Mn ions formed $MnO_4$ tetrahedra with the Mn-O bond length shortened by 0.01${\AA}$ and with reduced Debye-Waller factor in the thermally treated sample.

• Journal of the Korean Ceramic Society
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• v.39 no.2
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• pp.184-189
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• 2002

This study, compared with data of PbO-base glass system is a part of new glass composition design with Bi-base composition for PDP Rib. As $Bi_2O_3-B_2O_3-ZnO$ glass composition including Bi, which have similar density value and work facility to PbO, properties of softening point, thermal expansion coefficient, chemical durability, dielectric constant, and structural changing by XPS were investigated. $Bi_2O_3-B_2O_3-ZnO$ glass system, added 50∼80 wt% $Bi_2O_3$ widely, were presented 400∼480$^{\circ}C$ softening temperature, $68{\sim}72{\times}10^{-7}/^{\circ}C$ thermal expansion coefficient and 13∼25 dielectric constant. These results were showed similar physical properties with Pb-base glass system of same composition content, application possibility as starting composition of rib material was identified through micro-control of components and physical properties. The bonding energy of $O_{1s}$ as the $Bi_2O_3$ content decreasing was increased and full width at half-maximum (FWHM) was decreased, which is caused by non-bridging oxygen increasing.

• Journal of the Korean Magnetics Society
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• v.15 no.4
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• pp.246-249
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• 2005

The blue-color emitting phosphor powder, $CaMgSi_{2}O_6:Eu^{2+}(CMS:Eu^{2+})$ was synthesized by the solid-state reaction method. The synthesized powder was annealed from room temperature to $1,100^{\circ}C$ in air. Its PL property and valence state of Eu atoms was measured by the photoluminescence (PL) and the electron paramagnetic resonance (EPR) spectrometers, respectively. The PL intensity was stable to $700^{\circ}C$, but drastically decreased to $1,100^{\circ}C$. The behavior of EPR intensity was very similar to the PL intensity. The EPR measurement showed that decreased intensity of the PL was caused to the oxidation from the ion $Eu^{2+}$ to $Eu^{3+}$ ions. The EPR spectrometer was powerful as a tool that could distinguish between the valence states of Eu atom as a dopant in various phosphors.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.4 s.37
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• pp.275-280
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• 2005

We propose a new approach to greatly simplify the fabrication of conventional nanoimprint lithography (NIL) by combined nanoimprint and photolithography (CNP). We introduce a hybrid mask mold (HMM) made from UV transparent material with a UV-blocking Cr metal layer placed on top of the mold protrusions. We used a negative tone photo resist (PR) with higher selectivity to substrate the CNP process instead of the UV curable monomer and thermal plastic polymer that has been commonly used in NIL. Self-assembled monolayer (SAM) on HMM plays a reliable role for pattern transfer when the HMM is separated from the transfer layer. Hydrophilic $SiO_2$ thin film was deposited on all parts of the HMM, which improved the formation of SAM. This $SiO_2$ film made a sub-10nm formation without any pattern damage. In the CNP technique with HMM, the 'residual layer' of the PR was chemically removed by the conventional developing process. Thus, it was possible to simplify the process by eliminating the dry etching process, which was essential in the conventional NIL method.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.31-39
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• 2018

In this paper, we proposed a license plate detection method based on contour extraction that adapts to environmental changes. The proposed method extracts contour lines using DoG (Difference of Gaussian) to remove unnecessary noise parts in the contour extraction process. Binarization was applied in ugly outline images, and erosion and dilation operations were used to emphasize the contour of the character part. Then, only the outline of the ratio of the characters of the plate was extracted through the ratio of the width and height of the characters. And the case where the outline is the longest is estimated by estimating the characters of the license plate. For the experiment, we applied 130 image data to license plate on the front of the vehicle, oblique environment, and environment images with various backgrounds. I also experimented with motorcycle images of different license plate patterns. Experimental results showed that the detection rate of the oblique image was 93% and that of the various background environment was 70% in the motorcycle image but 98% in the front image.

• Journal of the Korean Ceramic Society
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• v.39 no.8
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• pp.721-727
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• 2002

In order to overcome trade-off among compositions, process and properties of the glasses with high PbO-base composition for PDP Rib, we studied glass crystallization and crystallization kinetics by Differential Thermal Analysis(DTA). Glass powder was obtained through melting/cooling/grinding, with 3 wt%TiO2 addition for the crystal nucleation and growth in $62PbO-19B_2O_3-10SiO_2-9(Al_2O_3-K_2O-BaO-ZnO)$(in wt%) composition glass. This powder was heat-treated for 1 to 10 h at $445^{\circ}C$ for nucleation. DTA measurements were performed to obtain the crystallization peak with $5∼25^{\circ}C/min$ heating rates. DTA crystallization peak temperature increased with increasing the heating rate and decreased with increasing the heating time. Because the Avrami parameter (n) was approximately 1, the surface crystallization occurred. The maximum nucleation time was 2 h.

• Korean Journal of Materials Research
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• v.11 no.4
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• pp.305-311
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• 2001

$PbO-B_2O_3-SiO_2-Al_2O_3$, system was investigated for optical, thermal and electrical properties of transparent dielectric. We also studied the reaction between transparent dielectric and transparent electrode(Indium Tin Oxide, ITO) during firing. For the evaluation of properties, dielectrics were prepared under the conditions fired at 520~58$0^{\circ}C$ with 12$\mu\textrm{m}$ thickness. In the reaction between dielectrics and electrode(ITO), In ions diffused into dielectric layer, while Sn ion diffusion was not observed. The coefficient of thermal expansion, the dielectric constant, the glass transition temperature and the transmittance of the dielectric were greatly dependent on PbO content. The increase of the coefficient of thermal expansion and the dielectric constant were monitored by increasing PbO, while the glass transition temperature and the transmittance were decreased. With the increased $Al_2O_3/B_2O_3$ ratio, the coefficient of thermal expansion and the transmittance were decreased, while the dielectric constant was increased. The glass transition temperature did not change significantly.