Inductively Coupled Plasma Analysis Research Articles

Effect of inorganic oxide supports on the activity of chromium‐based catalysts in ethylene trimerization

Novel heterogeneous catalysts were prepared using immobilization of bis(2‐decylsulfanylethyl)amine–CrCl3 (Cr‐SNS‐D) on various supports, namely commercial TiO2, Al2O3 and magnetic Fe3O4@SiO2 nanoparticles, to yield solid catalysts denoted as support@Cr‐SNS‐D. The structure of the catalysts was confirmed on the basis of spectroscopic analyses, N2 adsorption–desorption and inductively coupled plasma (ICP) analysis. The surface areas of Al2O3@Cr‐SNS‐D, Fe3O4@SiO2@Cr‐SNS‐D and TiO2@Cr‐SNS‐D catalysts were determined to be 70, 23 and 41 m2 g−1, respectively. A decrease in surface area from that of the supports clearly establishes accurate immobilization of Cr‐SNS‐D catalyst on the surface of the parent carriers. The loading of Cr was determined to be 0.02, 0.16 and 0.11 mmol g−1 for Cr‐SNS‐D supported on TiO2, Al2O3 and Fe3O4@SiO2, respectively, using ICP analysis. After preparation and full characterization of the catalysts, ethylene trimerization reaction was accomplished in 40 ml of dry toluene, at 80°C and 25 bar ethylene pressure and in the presence of methylaluminoxane (Al/Cr = 700) within 30 min. The supported chromium catalysts were found to be efficient and selective for the ethylene trimerization reaction. The highest activity (74 650 g1‐hexene gCr−1 h−1), as well as no polyethylene formation during reaction processes, was observed when TiO2 was used as the catalyst support.

Green synthesis of aminocarbonyl compounds using a nanostructured heterogeneous catalyst under mild reaction conditions

The synthesis of aminocarbonyl derivatives as biologically active compounds by using polyethylene glycol (PEG-400)-SO3H-coated Fe2O3 is reported. The heterogeneous nanocatalyst was prepared via in-situ co-precipitation method and its structure and morphology was characterized by Fourier-transform infrared spectroscopy, energy-dispersive X-ray analysis, X-ray diffraction pattern, field-emission scanning electron microscopy image, vibrating sample magnetometer curves, N2 adsorption-desorption isotherm and inductively-coupled plasma analysis. Noteworthy, the green composite nanocatalyst was applied for the one-pot multicomponent synthesis of aminocarbonyl compounds at room temperature. This work had advantages such as significant nanocatalyst activity, recoverability, short process time, mild reaction conditions and high products yields.

Investigation of Ni/C and Pt/C Catalyst Stability in an Anion Exchange Membrane (AEM) Fuel Cell

Anion exchange membrane fuel cells (AEMFC) have gained increasing research interest because its alkaline chemistry enables non-platinum group metal (non-PGM) catalysts to be used. Despite this opportunity, many researchers still focus on PGM material due to their performance. Often the approach is to minimize PGM content by using non-PGM supporting substrates, such as Pt-Ni foam and Pt-Ni/Ni-B catalysts in order to mitigate cost [1] [2]. Although the performances of both PGM and non-PGM catalysts have been thoroughly researched, their stability under an AEMFC environment is seldom questioned. This is because PGM materials, typically Pt, are noble metals and many non-PGM materials are considered stable under alkaline conditions, especially nickel. However, the Pt stability in PEMFCs has been severely challenged during fuel cell operations. Ferreira et al. reported the Pt catalyst particle aggregation with decreased PEMFC performance [3]. Helmly et al. reported Pt dissolution in a PEM electrolyte. In alkaline fuel cell operation, the amount of dissolved Pt was reported to be even higher than from PEM FC operation [4]. Hence, the Pt stability is of concern under AEMFC conditions. On the other hand, Ni stability does not appear to have been reported. Therefore, the focus of this study is to examine catalyst stability of Pt and Ni under identical AEMFC operating conditions. This study focuses on pure Pt and Ni carbon supported catalysts, which have been conventionally used to operate AEMFCs. To study and compare the two materials under the same test condition, both Ni/C and Pt/C catalysts were applied on the same AEMFC in separate locations as shown in Fig.1. A sandwiched AEM was used so that catalyst migration could be studied without interference from direct catalyst contact. The AEMFC was held at 0.9V by a potentiostat with H2 and O2 gas flowing at each specific electrode. Once per day, the cell open circuit potential (OCP) was measured without the imposed voltage. To identify any catalyst morphology change after 30 days (~500hrs) operation, scanning electron microscopy (SEM) was conducted on a cross section of each catalyst layer; transmission electron microscopy (TEM) was used to observe catalyst particles from each layer; inductively coupled plasma (ICP) analysis was used to determine if any catalyst could be detected in the middle AEM. The OCP was found to have dropped by 0.2V during the 30 day operation. Significant catalyst morphology changes were found at the cathode for both Ni/C and Pt/C catalysts. SEM analysis showed that the Ni material was found to develop a band like structure at the AEM-catalyst layer interface. The TEM analysis confirmed that the Ni nanoparticles developed a smeared shape on the carbon substrate, which was verified as a Ni oxide species using energy-dispersive X-ray (EDX) mapping. The SEM images showed that the Pt signal from the cathode catalyst layer was much weaker than the one from the anode. TEM analysis showed that the Pt remained as nanoparticles on the carbon substrate, but that the nanoparticle density appeared lower than on the anode, consistent with Pt dissolution. The ICP analysis showed both Ni and Pt in the middle AEM. The results indicate, substantial morphology changes occurred on both Ni/C and Pt/C catalysts during AEMFC operation. Additional research is needed to investigate the change of morphology mechanisms, which is key to developing enhanced stability of AEMFC catalysts. [1] Daping He, Libo Zhang, Dongsheng He, Gang Zhou, Yue Lin, Zhaoxiang Deng, Xun Hong, Yuen Wu, Chen Chen & Yadong Li, Amorphous nickel boride membrane on a platinum–nickel alloy surface for enhanced oxygen reduction reaction, Nature Communications volume 7, Article number: 12362 (2016) [2] Julia van Drunen, Brandy K. Pilapil, Yoseif Makonnen, Diane Beauchemin, Byron D. Gates, and Gregory Jerkiewicz, Electrochemically Active Nickel Foams as Support Materials for Nanoscopic Platinum Electrocatalysts, ACS Applied Materials & Interfaces 2014 6 (15), 12046-12061 [3] P. J. Ferreira, G. J. la O,, Y. Shao-Horna, D. Morgan, R. Makharia, S. Kocha, and H. A. Gasteiger, Instability of Pt ∕ C Electrocatalysts in Proton Exchange Membrane Fuel Cells A Mechanistic Investigation J. Electrochem. Soc. 2005 volume 152, issue 11, A2256-A2271 [4] Serhiy Cherevko, Aleksandar R. Zeradjanin, Gareth P. Keeley and Karl J. J. Mayrhofer, A Comparative Study on Gold and Platinum Dissolution in Acidic and Alkaline Media J. Electrochem. Soc. 2014 volume 161, issue 12, H822-H830 Figure 1

Corrosion Failure Analysis of the Convection Part of District Heating Peak Load Boiler, 지역난방 첨두부하보일러 대류부 부식 파손 분석

Corrosion failure in the convection part of peak load boiler (PLB) of the district heating system led to water leakage. Herein, Internal Rotary Inspection System (IRIS) inspection was employed to examine wall thinning and the cause of leakage in the flue tube. The corrosive products of the turbulator and tube were investigated using scanning electron microscope combined with energy dispersive spectroscopy, X-ray diffraction, and inductively coupled plasma (ICP). Majority of the serious corrosion damage was observed near the turbulator located in the upper flue tube. ICP analysis of the boiler water revealed oxide formation of sodium chloride in the lower end part of the flue tube. A cross-sectional view of the turbulator revealed the presence of double-layers of the oxide film, indicating environmental change during operation associated with water leakage. The outer surface of the turbulator consisted of the acid oxides such as NOx and SOx along with sodium and chloride ions. Dew-point corrosion is hypothesized as the main cause for the formation of acid oxides in the region of contact of the flue tube and the turbulator.

Combination of static magnetic field and cisplatin in order to reduce drug resistance in cancer cell lines

Purpose: In this study, the effects of different intensities of Static Magnetic Fields (SMFs) (10, 15 and 25 mT) and different concentrations of cisplatin drug were investigated on the viability percent and IC50 of the A2780 and A2780-CP cell lines at 24, 48 and 96 h to show useful potential of SMF as a physical agent to enhance the effectiveness of common therapeutic approaches and decrease of drug resistance to cisplatin anticancer drug.Materials and methods: Magnetic field exposure was performed using a locally designed generator. The cell viability percent, IC50 and cisplatin uptake in treated cells were evaluated by MTT assay and inductively coupled plasma (ICP), respectively.Results: Increasing of concentration and time of cisplatin drug showed a noticeable decrease in viability percent in sensitive and resistant cell lines compared with control group. These decreases were more significant in resistant cells compared with sensitive cells. The obtained IC50 values for resistant were greater than the values obtained for A2780 cells. ICP analysis demonstrated an increased uptake of cisplatin after treatment for 48 and 96 h relative to untreated groups in both resistant and sensitive cells.Conclusion: Results showed that A2780 cells were more sensitive to cisplatin than A2780-CP. Studies have shown that SMF can increase the effect of cisplatin on cell viability percent and decrease the resistance of A2780-CP cells by producing large, verruca shaped structures at the surface of the cell membrane.

The potential role of spherocrystals in the detoxification of essential trace metals following exposure to Cu and Zn in the fighting conch Strombus (Lobatus) pugilis.

Crypt cells-one of the three cell types composing Strombidae digestive tubules-are characterized by the presence of numerous metal-containing phosphate granules termed spherocrystals. We explored the bioaccumulation and detoxification of metals in Strombidae by exposing wild fighting conch Strombus pugilis for 9days to waterborne CuSO4 and ZnSO4. The total amount of Cu and Zn was determined in the digestive gland and in the rest of the body by Inductively Coupled Plasma (ICP) analyses. The digestive gland spherocrystal metal content was investigated based on the semi-quantitative energy dispersive X-ray (EDX) elemental analysis. ICP analyses of unexposed individuals revealed that 87.0 ± 5.9% of the Zn is contained in the digestive gland, where its concentration is 36 times higher than in the rest of the body. Regarding Cu, 25.8 ± 16.4% of the metal was located in the digestive gland of the control individuals, increasing to 61.5 ± 16.4% in exposed individuals. Both Cu and Zn concentrations in the digestive gland increased after exposures, pointing to a potential role of this organ in the detoxification of these metals. EDX analysis of spherocrystals revealed the presence of Ca, Cl, Fe, K, Mg, P, and Zn in unexposed individuals. No difference was found in the relative proportion of Zn in spherocrystals of exposed versus control individuals. Contrastingly, copper was never detected in the spherocrystals from controls and Zn-exposed individuals, but the relative proportion of Cu in spherocrystals of Cu-exposed individuals varied from 0.3 to 5.7%. Our results show the direct role of spherocrystals in Cu detoxification.

Application of laser-induced breakdown spectroscopy to Arctic sediments in the Chukchi Sea

Physical and geochemical investigations coupled with laser-induced breakdown spectroscopy (LIBS) were performed on three surface sediment cores (ARA02B/01A, ARA02B/02, and ARA02B/03A) recovered from the western Arctic Ocean (Chukchi Sea) during the IBRV ARAON 2011 expedition. The LIBS technique was applied to conduct elemental analysis of the Arctic sediments and compare the results to those obtained using an X-ray fluorescence (XRF) core scanner and inductively coupled plasma (ICP) system. The LIBS technique showed an elemental composition similar to that using XRF and ICP in each sediment core. Qualitative and semi-quantitative LIBS analyses provide distinguishable patterns between sediment cores, similar to those observed in the ICP analysis. In particular, the elemental pattern of LIBS responded to the color change of the sediment cores. Dark brown layers in the upper parts of the cores were indicated by the color indices and showed elevated Mn/Al ratios, suggesting the influence of regional variation in terrestrial input since the deglacial period. In this study, grain size distribution and contents of detrital dolomite and organic carbon as well as elemental composition (LIBS) were considered to determine sediment provenance and sedimentation environments during the Holocene. Furthermore, the present study showed that the LIBS technique may be used as an applicable method to unravel regional variations in sedimentary composition in the Arctic Ocean.

ICP Analyses from the Cinnabar-Mercury Occurrence at Azogues (Loma Guashon), Ecuador: Ancient Industrial Uses and Human Health Implications

ICP (Inductively Coupled Plasma) analyses of the Cretaceous marine sandstones at the Azogues (Loma Guashon), Ecuador cinnabar-mercury occurrence gave 11 - 113 ppm Hg. However, the ancient Azogues mines have been well documented previously, for example: 1) a 1799 hand drawn map “Plan del Cerro Mineral de Azogue” shows numerous adits; 2) during Colonial time, Cuenca founder, Gil Ramirez Davalos was owner of the mercury mines; 3) in the late 1800s, Teodoro Wolf described well-worked adits at Guashon and samples with 0.5% Hg; and more recently, 4) the Metallogenic Map of Ecuador shows the mercury occurrence at Azogues. Mineral resource assessment of the Azogues occurrence is important to regional archaeological studies of resource availability and ancient use of cinnabar as a pigment and as a source of mercury for gold amalgamation before the arrival of the Europeans, and possibly later, for silver amalgamation, during Colonial time.

Bromide and Acids: A Comprehensive Study on Their Role on the Hydrogen Peroxide Direct Synthesis

Hydrogen peroxide direct synthesis was studied using different concentrations of NaBr and H3PO4 (promoters) with a commercial Pd/C catalyst. The aim of the study was to understand the role of the acids and bromide on the catalyst and thus the effect on the direct synthesis. The experimental work was done in a continuous trickle bed reactor (TBR) using different concentrations of promoters. The effect of the promoters on the catalyst (Pd leaching and bromide adsorption) was monitored by inductively coupled plasma (ICP) on the solution obtained from the reaction environment. ICP analysis coupled with the monitoring of conversion, selectivity, and productivity helped to understand the effect of the promoters and to check the possibility to discriminate better the reaction network mechanism with different reaction conditions. Pd leaching was correlated to catalyst activity and bromide/phosphoric acid ratio. This work provides new and original evidence on the role of promoters, allowing one to understand bette...

Investigation of Changing Pore Topology and Porosity During Matrix Acidizing using Different Chelating Agents

Core flooding acidizing experiments on sandstone/carbonate formation are usually performed in the laboratory to observe different physical phenomena and to design acidizing stimulation jobs for the field. During the tests, some key parameters are analyzed such as pore volume required for breakthrough as well as pressure. Hydrochloric acid (HCl) is commonly used in the carbonate matrix acidizing while Mud acid (HF: HCl) is usually applied during the sandstone acidizing to remove damage around the well bore. However, many problems are associated with the application of these acids, such as fast reaction, corrosion and incompatibility of HCl with some minerals (illite). To overcome these problems, chelating agents (HEDTA, EDTA and GLDA) were used in this research. Colton tight sandstone and Guelph Dolomite core samples were used in this study. The experiments usually are defined in terms of porosity, permeability, dissolution and pore topology. Effluent samples were analyzed to determine dissolved iron, sodium, potassium, calcium and other positive ions using Inductively Coupled Plasma (ICP). Meanwhile Nuclear Magnetic Resonance (NMR) was employed to determine porosity and pore structure of the core sample. Core flood experiments on Berea sandstone cores and dolomite samples with dimensions of 1.5 in × 3 in were conducted at a flow rate of 1 cc/min under 150oF temperature. NMR and porosity analysis concluded that applied chemicals are effective in creating fresh pore spaces. ICP analysis concluded that HEDTA showed good ability to chelate calcium, sodium, magnesium, potassium and iron. It can be established from the analysis that HEDTA can increase more amount of permeability as compared to other chelates.

Cu(acac)2–PVA composite nanofibers in catalysis of Michael addition of carbon nucleophiles to α,β-unsaturated carbonyl compounds

Copper (II) acetylacetonate containing nanofibers of polyvinyl alcohol (Cu(acac)2–PVA) were prepared by electrospinning and characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, inductively coupled plasma (ICP) and diffuse reflectance spectroscopy. The obtained nanofibers were almost uniform and uniaxially aligned with their longitudinal axes oriented randomly and no entanglement was observed between them. It was also found that Cu(acac)2 was embedded as distinct nanoparticles inside and over the walls of the nanofibers. The obtained nanocomposite was successfully used as a recoverable heterogeneous catalyst in the Michael addition reaction of carbon nucleophiles such as malononitrile, indole and 2-methylindole to various α,β-unsaturated carbonyl compounds. The Michael addition reaction proceeded smoothly at room temperature in dry THF. Under very mild reaction conditions, good to excellent yields of the desired products were obtained. Although one favorable feature of the catalyst was ease of recycling, a minor decrease in its efficiency during successive runs was observed. It was found that 7% decrease in efficiency after four successive runs may be due to the slight leaching of Cu(acac)2 into the solution based on an ICP analysis of the recovered catalyst of the fourth run.

Enhanced sulfidation xanthate flotation of malachite using ammonium ions as activator

In this study, ammonium ion was used to enhance the sulfidation flotation of malachite. The effect of ammonium ion on the sulfidation flotation of malachite was investigated using microflotation test, inductively coupled plasma (ICP) analysis, zeta potential measurements, and scanning electron microscope analysis (SEM). The results of microflotation test show that the addition of sodium sulfide and ammonium sulfate resulted in better sulfidation than the addition of sodium sulfide alone. The results of ICP analysis indicate that the dissolution of enhanced sulfurized malachite surface is significantly decreased. Zeta potential measurements indicate that a smaller isoelectric point value and a large number of copper-sulfide films formed on the malachite surface by enhancing sulfidation resulted in a large amount of sodium butyl xanthate absorbed onto the enhanced sulfurized malachite surface. EDS semi-quantitative analysis and XPS analysis show that malachite was easily sulfurized by sodium sulfide with ammonium ion. These results show that the addition of ammonium ion plays a significant role in the sulfidation of malachite and results in improved flotation performance.

New Acid Combination for a Successful Sandstone Acidizing

With the development of new enhanced oil recovery techniques, sandstone acidizing has been introduced and played a pivotal role in the petroleum industry. Different acid combinations have been applied, which react with the formation, dissolve the soluble particles; thus increase the production of hydrocarbons. To solve the problems which occurred using current preflush sandstone acidizing technology (hydrochloric acid); a new acid combination has been developed. Core flooding experiments on sandstone core samples with dimensions 1.5 in. × 3 in. were conducted at a flow rate of 2 cm3/min. A series of hydrochloric-acetic acid mixtures with different ratios were tested under 150°F temperature. The core flooding experiments performed are aimed to dissolve carbonate, sodium, potassium and calcium particles from the core samples. These experiments are followed by few important tests which include, porosity-permeability, pH value, Inductively Coupled Plasma (ICP) analysis and Nuclear Magnetic Resonance (NMR measurements). All the results are compared with the results of conventional hydrochloric acid technology. NMR and porosity analysis concluded that the new acid combination is more effective in creating fresh pore spaces and thus increasing the reservoir permeability. It can be seen from the pore distribution before and after the acidizing. Prior applying acid; the large size of pores appears most frequently in the pore distribution while with the applied acid, it was found that the small pore size is most the predominant of the pore distribution. These results are validated using ICP analysis which shows the effective removal of calcium and other positive ions from the core sample. This study concludes that the combination of acetic-hydrochloric acid can be a potential candidate for the preflush stage of sandstone acidizing at high temperature reservoirs.

Impurities Removal in Seawater to Optimize the Magnesium Extraction

Magnesium extraction from seawater is promising way because magnesium is the second abundant element in seawater and Indonesia has the second longest coastline in the world. To optimize the magnesium extraction, the impurities in seawater need to be eliminated. Evaporation and dissolving process were used in this research to remove the impurities especially calcium in seawater. Seawater which has been evaporated from 100 ml to 50 ml was dissolved with variations solution such as oxalic acid and ammonium bicarbonate. The solution concentration is 100 g/l and it variations are 2 ml, 4 ml, 6 ml, 8 ml, 10 ml, 20 ml, 30 ml, 40 ml and 50 ml. This step will produce precipitate and filtrate then it will be analysed to find out the result of this process. The precipitate was analysed by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) but the filtrate was analysed by Inductively Coupled Plasma (ICP). XRD analysis shows that calcium oxalate and calcium carbonate were formed and ICP analysis shows that the remaining calcium in seawater using oxalic acid is about 0.01% and sodium 0.14% but when using ammonium bicarbonate the remaining calcium is 2.5% and sodium still more than 90%. The results show that both oxalic acid and ammonium bicarbonate can remove the impurities but when using oxalic acid, not only the impurities but also magnesium was precipitated. The conclusion of this research is the best solution to remove the impurities in seawater without precipitate the magnesium is using ammonium bicarbonate.

Chromium(VI) reduction in aqueous medium by means of catalytic membrane reactors

A novel method for catalytic reduction of chromium(VI) to chromium(III) in model and real water is proposed in this work. Hydrogen was used as a reducer. Three different catalytic membrane reactors were prepared and employed in the studied reaction. The catalytic membrane reactors were prepared using commercial corundum hollow fiber membranes. The active phases, palladium, cerium oxide, iron oxide or combinations of them, were incorporated by incipient wetness impregnation of the corresponding water-soluble salts followed by calcination and reduction. The catalytic tests were performed in semi-batch mode at ambient conditions. A mass flow controller was used to supply hydrogen to one end of the membrane whilst the other end was kept closed. The reactors were submerged into a vessel containing the chromate solution. The concentration of the chromate was continuously monitored following a standard analytical method. The initial chromate concentration was varied between 0.5 and 18mgL−1. In order to completely reduce the Cr(VI) to Cr(III), it was necessary to decrease the pH of the solution to 3. In the end of the tests the final solutions were neutralized to pH 8 and filtered. The content of chromium in the final solutions and in the precipitates was determined by inductively coupled plasma (ICP) technique. It was demonstrated that for the studied reaction the presence of palladium is essential. In all experiments, with synthetic and real water adjusted to pH 3, the catalytic membrane reactors containing palladium (0.3–0.9w/w%) effectively reduced the chromium to levels below 0.03mgL−1 without losing activity in repetitive runs. The results from ICP analyses demonstrated that the chromium can be completely eliminated from the water after neutralization and filtration.

Synthesis and in vitro evaluation of electrodeposited barium titanate coating on Ti6Al4V

Osseointegration has been the concern of implantology for many years. Researchers have used various ceramic coatings for this purpose; however, piezoelectric ceramics (e.g., barium titanate [BTO]) are a novel field of interest. In this regard, BTO (BaTiO3) coating was fabricated by electrophoretic deposition on Ti6Al4V medical alloy, using sol-gel-synthesized nanometer BTO powder. Structure and morphologies were studied using X-ray diffraction and scanning electron microscopy (SEM), respectively. Bioactivity response of coated samples was evaluated by SEM and inductively coupled plasma (ICP) analysis after immersion in simulated body fluid (SBF). Cell compatibility was also studied via MTT assay and SEM imaging. Results showed homogenous coating with cubic structure and crystallite size of about 41 nm. SEM images indicated apatite formation on the coating after 7 days of SBF immersion, and ICP analysis approved ions concentration decrement in SBF. Cells showed flattened morphology in intimate contact with coating after 7 days of culture. Altogether, coated samples demonstrated appropriate bioactivity and biocompatibility.

Reductive amination of furfural toward furfurylamine with aqueous ammonia under hydrogen over Ru-supported catalyst

Poly(N-vinyl-2-pyrrolidone)-capped ruthenium-supported hydroxyapatite (Ru-PVP/HAP) shows significant activity for the synthesis of furfurylamine (FAM) via the reductive amination of furfural. As-prepared 5 wt% Ru-PVP/HAP affords 50 % yield of FAM in 25 % NH3 aqueous solution under pressurized H2 gas (2.5 atm), and the highest yield approaches 60 % at 4.0 H2 atm. Comparison between the activities over four Ru-supported HAP catalysts prepared with different methods and the results of X-ray absorption spectroscopy suggested that the metallic Ru cluster is the active center for the reductive amination of furfural. Transmission electron microscope and inductively-coupled plasma analysis indicated that the as-prepared 5 wt% Ru-PVP/HAP catalyst possessed 4.0 wt% PVP-capped Ru clusters with average diameter of 1.7 ± 0.3 nm on HAP support. It was also demonstrated that the reductive amination approach with Ru-PVP/HAP catalyst, NH3 aq. and pressurized H2 gas has capability for transformation of aromatic aldehydes to the corresponding aromatic amines. According to these results, it is concluded that Ru(0) cluster supported on HAP will represent a suitable catalyst for widely-usable reductive amination to convert an aldehyde functionality towards an amine.

Plasma Sputtering for Fabrication of Antibacterial and Ultraviolet Protective Fabric

In this study, we have used a DC magnetron sputtering system for creating antibacterial and ultraviolet protective cotton fabrics. A silver anode and cathode were used, and samples were placed on the anode. The cathode particles were scattered by attacking active ions, radicals, and electrons. Time of exposure and gas pressure was changed parameters of plasma. Silver particles were deposited on the both sides of cotton samples, and the antibacterial property has been developed, through sputtering of silver particles on fabric surfaces. ICP (Inductively Coupled Plasma) analysis was carried out to investigate the silver ion content on cotton fabrics. The antibacterial properties of the fabrics were connected with the presence of Ag on their surface. The antibacterial efficiency was determined by bacterial counting test. After plasma treatment, the physical and chemical properties of the fabrics were examined by surface analysis methods and textile technology tests. Also treated cotton fabrics had an excellent UV-blocking property. UPF value of the silver sputtered cotton fabric reached to 264. According to the standard, the treated cotton fabric can claim to be a “UV Protective product”. The experimental work suggests that the change in properties induced by plasma can effect an improvement in certain textile products.

Cr(VI)-6-Methylquinoline을 이용한 치환 벤질 알코올류의 산화반응과 속도론에 관한 연구

MQCC (Cr(VI)-6-methylquinoline) complex was synthesized by the reaction of 6-methylquinoline with chromium(VI) trioxide in 6 M HCl. The structure was characterized using IR (Infrared Spectroscopy) and ICP (Inductively Coupled Plasma) analysis. The oxidation of benzyl alcohol using 6-MQCC in various solvents showed that the reactivity increased with the increase of the dielectric constant, in descending order of DMF > acetone > chloroform > cyclohexene. In the presence of DMF solvent with acidic catalyst such as sulfuric acid (H2SO4 solution), 6-MQCC oxidized benzyl alcohol (H) and its derivatives (p-OCH3, m-CH3, m-OCH3, m-Cl, m-NO2) were effectively oxidized. Electron-donating substituents accelerated the reaction rate, whereas electron acceptor groups retarded the reaction rate. The Hammett reaction constant (ρ) was -0.69 (308 K). The observed ex- perimental data was used to rationalize the fact that the hydride ion transfer occurred at the rate-determining step.

Green Gold—Dirty Gold, Tadó, Dept. Chocó, Colombia

In place of mercury, small-scale alluvial gold miners in Tadó, Dept. Chocó, Colombia produce “green gold” (oroverde) using locally available plant extracts. The leaves of Balso (Ochroma pyramidale) and Malva (Hibiscus furcellatus) are crushed by hand and are mixed with water to make a foamy liquid that is added to the gold pan (batea) instead of mercury. After the plant extract is added, the gold, magnetite, and other heavy minerals sink and the lighter minerals are floated out of the gold pan. For final clean-up, a combination of other methods may be used. However, ICP (Inductively Coupled Plasma) analyses indicate that even green gold contains 208 - 4530 ppm Hg—this mercury may have been released from dragas or other small-scale gold mining operations that continue to use mercury; coal burning; volcanism; or native mercury released from cinnabar occurrences. ICP also indicates 308 - 106,000 ppm Ag and 452 - 585 ppm Pt.