• Journal of Electrochemical Science and Technology
• /
• v.3 no.1
• /
• pp.44-49
• /
• 2012

Electrochemical and photochemical techniques have been proved to be effective for the removal of organic pollutants in textile wastewater. The present study deals with degradation of synthetic textile effluents containing reactive dyes and assisting chemicals, using electro oxidation and photo catalytic treatment. The influence of various operating parameters such as dye concentration, current density, supporting electrolyte concentration and lamp intensity on TOC removal has been determined. From the present investigation it has been observed that nearly 70% of TOC removal has been recorded for electrooxidation treatment with current density 5 mA/$dm^2$, supporting electrolyte concentration of 3 g/L and in photocatalytic treatment with 250 V as optimum lamp intensity nearly 67% of TOC removal was observed. The result indicates that electro oxidation treatment is more efficient than photocatalytic treatment for dye degradation.

• Horticultural Science & Technology
• /
• v.30 no.2
• /
• pp.158-161
• /
• 2012

The influence of lysophosphatidylethanolamine (LPE) on anti-senescence of melon leaves and the change in fruit quality during the storage at low temperature were studied. In most of the crops, freshness of leaves is important factor for characteristics of fruits, such as sugar contents, color, and firmness. Melon ($Cucumis$ $melo$ L. cv. Prince) plants were sprayed with LPE at 5 and 3 weeks before commercial harvest. In upper part, LPE treatment showed slight high number of fresh leaf compared to no treatment (None). However, in lower part, LPE resulted in apparent inhibition effect on senescence, showing that lower side of melon plant kept fresh upon LPE application up to about 30%. The SSC of melon treated with LPE was similar to that of fruit from None at harvest. There was no change in soluble solids content (SSC) for all treatment during the storage at $7^{\circ}C$. There were no significant differences in firmness of mesocarp from melons given different treatments at harvest. The firmness of mesocarp from melon treated with LPE was higher than none after 2 weeks storage. The electrolyte leakage means for melon treated with LPE did not differ significantly from the means at initial storage after 2 weeks storage among the treatments. None increased 57% from its initial electrolyte leakage during storage. These results suggest that the application of LPE may have potential to inhibit senescence of leaves and maintain fruit quality during the storage in melon.

• The Journal of Korean Academy of Prosthodontics
• /
• v.43 no.5
• /
• pp.684-693
• /
• 2005

Statement of problem: Ti-6Al-7Nb alloy is used instead of Ti-6Al-4V alloy that was known to have toxicity. Purpose: This study was performed to investigate the effect of electrolyte concentration on the surface characteristics of anodized and hydrothermally-treated Ti-6Al-7Nb alloy Materials and methods: Discs of Ti-6Al-7Nb alloy of 20 mm in diameter and 2 mm in thickness were polished sequentially from #300 to 1,000 SiC paper ultrasonically washed with acetone and distilled water for 5 min, and dried in an oven at $50^{\circ}C$ for 24 hours. Anodizing was performed at current density $30mA/cm^2$ up to 300 V in electrolyte solutions containing $\beta-glycerophosphate$ disodium salt hydrate $(\beta-GP)$ and calcium acetate (CA). Hydrothermal treatment was conducted by high pressure steam at $300^{\circ}C$ for 2 hours using a autoclave. All samples were soaked in the Hanks' solution with pH 7.4 at $36.5^{\circ}C$ for 30 days. Results and conclusion: The results obtained were summarized as follows: 1. After hydrothermal treatment, the precipitated HA crystals showed the dense fine needle shape. However, with increasing the concentration of electrolyte they showed the shape of thick and short rod. 2. When the dense fine needle shape crystals was appeared after hydrothermal treatment, the precipitation of HA crystals in Hanks' solution was highly accelerated. 3. The crystal structures of $TiO_2$ in anodic oxide film were composed of strong anatase peak and weak rutile peak as analyzed with thin-film X-ray diffractometery. 4. The Ca/P ratio of the precipitated HA layer was equivalent to that of HA crystal in Hanks' solution.

• Journal of the Korean institute of surface engineering
• /
• v.33 no.5
• /
• pp.373-380
• /
• 2000

The flow melting behavior of the electrolytic tinplate during reflow treatment was investigated in terms of morphology and structure of coating layers which were electrodeposited with variation of electrolyte temperature. It was commonly found that the nucleation density of the electrodeposits showed little difference with the electrolyte temperature, and the growth of electrodeposited tin occurred along <100> direction of (002) plane. At low electrolyte temperature, the (002) plane of tin nucleated paralleling to the substrate and grew perpendicularly to the substrate, which rendered porous rod-like deposits. With increasing the temperature, the (002) plane nucleated declining $15^{\circ}$ to the substrate and also grew to the normal <100> direction, which enabled lateral growth of the tin crystals and rendered compact deposits. During reflow treatment, the matte deposit transformed to the reflowed state via transition regions consisted of contraction, island formation, and wetting . The matte deposits formed at low temperature exhibited wide transition regions because of poor thermal transfer between crystals due to their porous nature. While that formed at high temperature transformed very rapidly to the reflowed state by enhanced thermal transfer between the compact crystals.

• Membrane Journal
• /
• v.32 no.1
• /
• pp.43-49
• /
• 2022

Solid-state supercapacitors with high safety and robust mechanical properties are attracting global attention as next-generation energy storage devices. As an electrode of a supercapacitor, an economical carbon-based electrode is widely used. However, when an aqueous electrolyte is introduced, the charge transfer resistance increases because the interfacial contact between the hydrophobic electrode surface and aqueous electrolyte is not good. In this regard, we propose a method to obtain higher electrochemical performance based on improved interfacial properties by treating the electrode surface with oxygen plasma. The surface hydrophilization induced by the enriched oxygen functionalities was confirmed by the contact angle measurement. As a result, the degree of hydrophilization was easily adjusted by controlling the power and duration of the oxygen plasma treatment. As the electrolyte of the supercapacitor, PVA/H₃PO₄, which is a typical solid-state aqueous electrolyte, was used. Free-standing membranes of PVA/H₃PO₄ electrolyte were prepared and then pressed onto the electrode. The optimal condition was to perform oxygen plasma treatment for 5 seconds with a low power of 15 W, and the energy density of the supercapacitor increased by about 8%.

• Journal of Korean Society of Forest Science
• /
• v.99 no.2
• /
• pp.244-250
• /
• 2010

The aim of this study was to investigate relationship among seed viability and enzymes activities involved in scavenging reactive oxygen species (ROS), especially, superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT). In other respects, osmopriming has been demonstrated to reinvigorate aged seeds. Various viabilities of seeds that were ranged from 80 to 100% of germination rate could be produced using osmopriming and accelerated aging treatments. Priming treatment of Pinus thunbergii seeds for 3 days at $15^{\circ}C$ with a polyethylene glycol solution at -1.2 MPa improved their subsequent germination at $25^{\circ}C$. Accelerated aging (3, 6, 9, and 12 days at $41^{\circ}C$ and 100% relative humidity) decreased seed germination percentage depending on aging treatment duration. Electrolyte conductivities of seeds were measured as assay of membrane integrity. The conductivity from electrolyte leakage of P. thunbergii seed was also correlated with seed germinability. Conductivity for control seeds that had 95% of germination percentage was 3.48 ${\mu}S\;g^{-1}$, but jumped as doubled (7.98 ${\mu}S\;g^{-1}$) in 12-day-aged seed that had 80% of germination percentage. Our results demonstrate that aging of P. thunbergii seeds is associated with changes in the electrolyte leakage, lipid peroxidation, and antioxidant defense system. Priming of aged seeds progressively restored the initial germinative ability and resulted in a marked decrease in the levels of MDA and conductivity of seed leachate. These effects of priming were also well recovered of GR and CAT activities in aged seed. The improved seed quality by priming treatment appears at least partly attributable to reduced lipid peroxidation, resulting from enhanced antioxidative enzyme activities that are suggesting the antioxidant defense systems play a key role in seed vigor.

• Journal of Electrochemical Science and Technology
• /
• v.13 no.4
• /
• pp.424-430
• /
• 2022

In the study, Ni²⁺ (nickel) removal from synthetically prepared wastewater by electrocoagulation method, which is one of the electrochemical treatment processes, was investigated and parameters such as current density, pH, mixing speed, initial Ni²⁺ concentration, supporting electrolyte type and concentration were determined to determine Ni²⁺ removal efficiencies effects were studied. Experiment conditions during 30 minutes of electrolysis; the current density was determined as 0.95 mA/cm², the initial pH of the wastewater was 6, the mixing speed was 150 rpm, and the initial nickel concentration was 250 mg/L. The Ni²⁺ removal efficiency was obtained as 75.99% under the determined experimental conditions, while the energy consumption was calculated as 3.15 kW-h/m³. In the experiments, it was observed that the type and concentration of the supporting electrolyte did not have a significant effect on the Ni²⁺ removal efficiency. In the trials where the effect of the support electrolyte concentration was examined, the Ni²⁺ removal efficiency was 75.99% in the wastewater environment without the supporting electrolyte, while the Ni²⁺ removal efficiency was 81.55% when 7.5 mmol/L NaCl was used after the 30-minute reaction, and the energy consumption was 2.15 kW-h/m³ obtained as. As a result of the studies, it was concluded that the electrocoagulation process can be applied in the treatment of wastewater containing Ni²⁺.

• Laser Solutions
• /
• v.13 no.4
• /
• pp.21-24
• /
• 2010

Plasma electrolyte oxidation (PEO) surface treatment of magnesium alloy, an optical analysis method through reflection spectra were measured. As a result, the sample is formed on the membrane form of MgO or $Mg(OH)_2$ is in the form of oxide. The wavelength energy of surface treatment of magnesium alloy sample observed 0.23eV red shift. The measured reflectance spectra observed with the three different signals. This is due to $Mg(OH)_2$ oxide layer formed on porous hole.

• Journal of the Korean Ceramic Society
• /
• v.36 no.11
• /
• pp.1205-1210
• /
• 1999

Ceria based electrolytes were fabricated by a plasma spraying method. The porosity which was crated during the plasma spraying process was infiltrated with Ce0.8Gd0.2O2 sol by ultrasonic treatment and heat treatment at 90$0^{\circ}C$ in order to improve physical and electrical properties. The porosity decreased from 9.8% to 6.5% and gas permeability at 80$0^{\circ}C$ decreased from 16.7$\times$10-3 to 5.7$\times$10-3 cm3(STP)/cm2.s.cmHg as the number of treatment increased 10 cycles. The ionic conductivity was also increased about 30% after 10 times of sealing.

• Korean Journal of Veterinary Service
• /
• v.45 no.4
• /
• pp.337-342
• /
• 2022

Calf diarrhea is a major health concern in the livestock industry that requires accurate analysis for appropriate treatment. Dehydration and electrolyte imbalance are the most significant consequences of diarrhea in calves. Until now, the reference values of blood analysis of Hanwoo neonatal calves have not been well known. Recently, portable blood analyzers have made it possible to immediately analyze blood in the farm and provide suitable treatment for the patients. We analyzed electrolytes, blood urea nitrogen (BUN) and glucose in the blood of 179 Hanwoo neonatal calves, including 79 with diarrhea. These 179 calves were divided into 3 groups based on their age. Values of sodium (Na⁺ ) and glucose were significantly lower in diarrheic calves (1~30 days), while potassium (K⁺ ) and chloride (Cl^- ) values were higher in diarrheic calves (1~30 days). BUN values, which are closely related to dehydration due to diarrhea, increased in diarrheic calves of all ages. Therefore, these data can be used as reference values for blood analysis and treatment of healthy or diarrheic Hanwoo neonatal calves within 30 days of age.