• Analytical Science and Technology
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• 제37권1호
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• pp.63-78
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• 2024

The continuous increasing of the global demand of copper and nickel metals raises the interest in developing alternative technologies to produce them from copper sulfide ore. Also, in line with Egypt's vision 2030 for achieving the sustainable socioeconomic development which aims at developing alternative and eco-friendly technologies for processing the Egyptian ores to produce these strategic products instead of its importing. These metals enhance the advanced electrical and electronic industries. The current work aims at investigating the recovery of copper and nickel from Abu Swayeil copper ore using pug leaching technique by sulfuric acid. The factors affecting the pug leaching process including the sulfuric acid concentration, leaching time and temperature have been investigated. The copper ore sample was characterized chemically using X-ray fluorescence (XRF) and scanning electron microscope (SEM-EDX). A response surface methodology develops a quadratic model that expects the nickel and copper leaching effectiveness as a function of three controlling factors involved in the procedure of leaching was also investigated. The obtained results showed that the maximum dissolution efficiency of Ni and Cu are 99.06 % and 95.30%, respectively which was obtained at the following conditions: 15 % H₂SO₄ acid concentration for 6 hr. at 250 ℃. The dissolution kinetics of nickel and copper that were examined according to heterogeneous model, indicated that the dissolution rates were controlled by surface chemical process during the pug leaching. The activation energy of copper and nickel dissolution were 26.79 kJ.mol^-1 and 38.078 kJ.mol^-1 respectively; and the surface chemical was proposed as the leaching rate-controlling step.

• Proceedings of the Plant Resources Society of Korea Conference
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.111-111
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• 2018

Aronia (black chokeberry), a species of berries is source to a very large number of bioactive compounds like polyphenols, flavonoids, anthocyanins, and tannins in comparison to any other species. Owing to its antioxidant, anti-carcinogenic, anti-aging and anti-inflammatory properties. Fermentation- a bioconversion process exploiting the biological metabolic reaction of micro-organisms, has several benefits like improving the efficacy and safety of physiologically active substances, generation of new functional material, improving the adsorption rate and many others. Antigens like pathogens, food, pollen etc., generate a protective immune response in body tissues, and the process be referred to as inflammation. However, this when excessive results in a condition referred to as refractory inflammatory disease, whose incidence is increasing in the recent times, especially amongst children. The current study intended to assess the anti-oxidant activity, presence of polyphenols and anti-inflammatory efficacy of Aronia extract fermented by Lactic acid bacteria isolated from fermented sea foods. Aronia fruits collected from Sunchang, Chonbuk were lyophilized for fermentation. So as to maximise the efficacy of the fermented Aronia extract, the quantitative effects of lactic acid bacteria species, composition of extraction solution, influence of temperature and time on antioxidant activity and total polyphenol contents were investigated using an experimental design. Anti-inflammatory activity was evaluated on NO and cytokine ($TNF-{\alpha}$, IL-6) production in LPS activated Raw 264.7 cells. Results indicated that antioxidant effect and total polyphenol contents were best improved in extract of Aronia fermented by P. pentosaceus. In addition, NO and cytokine ($TNF-{\alpha}$, IL-6) levels were decreased significantly after fermentation. Thus, it was found that the anti-inflammatory activity of Aronia greatly increased after fermentation process using P. pentosaceus.

• The Research Journal of the Costume Culture
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• 제17권6호
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• pp.1129-1140
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• 2009

The pine needles has been used as medicines and it is using as dyeing as well as food. It is distributed through 50% in Korean forest. The pine needles is related to antimicrobial activity, however, dyeing properties of the extract components and effects of them are not well known yet. To examine dyeing properties of the pine needles extract, various fabrics(nylon, silk, wool, and soybean) were dyed under different dyeing conditions, and mordanted with one of five mordants(Al, Sn, Fe, Cr, and Cu). Dye uptake, Colors and Colorfastness of the dyed fabrics were measured. By the K/S values, dye uptake of all the dyed fabrics enhanced as increasing dyeing temperature and dyeing time. The highest K/S values were obtained from the protein fiber(wool and silk) fabrics dyed with water extract at $100^{\circ}C$, and with ethanol extract at $90^{\circ}C$ for 80 minutes. Colors of the dyed fabrics showed variety of yellow, brown and green colors. Colors changed by using Cu, Fe and Cr mordants: Cr-mordanted fabrics into light green, Fe-mordanted fabrics into reddish brown, and Cu-mordanted fabrics into deep green in ethanol extraction. Dry-cleaning fastness of the dyed fabrics presented good to excellent except wool fabrics dyed with ethanol extract. Washing fastness of the dyed nylon and soybean fabrics were good to excellent but wool and silk fabrics showed average grades. Most dyed fabrics were poor to light fastness.

• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.969-977
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• 2024

Indigo is a valuable, natural blue dye that has been used for centuries in the textile industry. The large-scale commercial production of indigo relies on its extraction from plants and chemical synthesis. Studies are being conducted to develop methods for environment-friendly and sustainable production of indigo using genetically engineered microbes. Here, to enhance the yield of bioindigo from an E. coli whole-cell system containing tryptophanase (TnaA) and flavin-containing monooxygenase (FMO), we evaluated tryptophan transporters to improve the transport of aromatic compounds, such as indole and tryptophan, which are not easily soluble and passable through cell walls. Among the three transporters, Mtr, AroP, and TnaB, AroP enhanced indigo production the most. The combination of each transporter with AroP was also evaluated, and the combination of AroP and TnaB showed the best performance compared to the single transporters and two transporters. Bioindigo production was then optimized by examining the culture medium, temperature, isopropyl β-D-1-thiogalactopyranoside concentration, shaking speed (rpm), and pH. The novel strain containing aroP and tnaB plasmid with tnaA and FMO produced 8.77 mM (2.3 g/l) of bioindigo after 66 h of culture. The produced bioindigo was further recovered using a simple method and used as a watercolor dye, showing good mixing with other colors and color retention for a relatively long time. This study presents an effective strategy for enhancing indigo production using a combination of transporters.

• Korean Journal of Veterinary Research
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• 제30권1호
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• pp.65-71
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• 1990

Rabbits were experimentally infected with rabbit hemorrhagic disease virs and the viral pathogenicity, hemagglutinability, and the effect of physicochemical factors were studied. The experimental results were summariaed as follows: 1. Mean rectal temperature of 11 infected rabbits was $40.0{\pm}0.47^{\circ}C$ prior to the virus inoculation, and $39.9{\pm}0.75^{\circ}C$ after 12hrs., $40.2{\pm}0.65^{\circ}C$ after 24hrs., $40.1{\pm}0.77^{\circ}C$ after 36hurs, and $40.6{\pm}0.56^{\circ}C$ just before the death. 2. Mean death time of infected rabbits was $40.3{\pm}22.0$ honrs and its range was 24 to 93 hours. 3. O, B, AB and A type of human erythrocytes were shown their HA in the order, but rabbit and chicken erythrocytes were not hemagglutinated by the virus. 4. In the hemagglutination, less than 0.25 per cent of a final concentration of erythrocytes and 0.2 per cent of BSA in PBS resulted in the best hemagglutination. Phosphate concentration in a range of 0.01M to 0.10M in PBS was not influenced on the hemagglutination reaction, and its pH 7.0 resulted in a better HA. 5. The hemagglutinating titers, in log 2 scale, of organs and tissues of the virus infected rabbits were $9.3{\pm}3.8$ (liver), $9.1{\pm}3.9$ (blood), $6.2{\pm}2.6$ (spleen) and $5.0{\pm}2.5$ (kidney). 6. The physicochemical factors such as heating ($50^{\circ}C$, 10 min.), trypsin treatment (0.05 pre cent, 5 min.), acid treatment (pH 3.0, 20 min.) and ether extraction (3 times) were not affective to the stability of virus and viral HA activities.

• Journal of Soil and Groundwater Environment
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• 제20권6호
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• pp.95-102
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• 2015

The purpose of this study is to compare the degradation characteristics by subcritical water of RDX contaminated soil using batch mode and dynamic mode devices. First, upon application of RDX contaminated soil, RDX treatment efficiency was increased with increasing the temperature in both modes. At 150℃, the treatment efficiency was 99.9%. RDX degradation efficiency got higher with lower ratio of solid to liquid. However, the treatment efficiency in the dynamic mode tended to be decreased at a certain ratio of solid to liquid or lower. The treatment efficiency was increased when it took longer time for the reactions in both modes. As the results of analysis on concentration of treated water after subcritical water degradation, the RDX recovery rate of dynamic and batch modes at 150℃ was 10.5% and 1.5%, respectively. However, both modes showed very similar recovery rates at 175℃ or higher. RDX degradation products were analyzed in treated water after it was treated with subcritical water. According to the results, RDX degradation mechanism was mostly oxidation reaction and reduction reaction was partially involved. Therefore, it suggested that most of RDX in soil was degraded by oxidation of subcritical water upon extraction. According to this result, it was found that both batch and dynamic modes were very effectively applied in the treatment of explosive contaminated soil.

• Clean Technology
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• 제22권4호
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• pp.250-257
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• 2016

As an attempt to replacing petroleum-based chemicals with bio-based ones, synthesis of furfural from biomass-derived xylose attracts much attention in recent days. Conventionally, furfural from xylose has been produced via the utilization of highly corrosive, toxic, and environmentally unfriendly mineral acids such as sulfuric acid or hydrochloric acid. In this study, microwave-assisted biphasic reaction process in the presence of novel bio-based heterogeneous acid catalysts was developed for the eco-benign and effective synthesis of furfural from xylose. The microwave was irradiated for reaction acceleration and a biphasic system consisting of $H_2O$ : MIBK (1 : 2) was designed for continuous extraction of furfural into the organic phase in order to reduce the undesired side products formed by decomposition/condensation/oligomerization in the acidic aqueous phase. Moreover, sulfonated amorphous carbonaceous materials were prepared from wood powder, the most abundant lignocellulosic biomass. The prepared catalysts were characterized by FT-IR, XPS, BET, elemental analysis and they were used as bio-based heterogeneous acid catalysts for the dehydration of xylose into furfural more effectively. For further optimization, the effect of temperature, reaction time, water/organic solvent ratio, and substrate/catalyst ratio on the xylose conversion and furfural yield were investigated and 100% conversion of xylose and 74% yield of furfural was achieved within 5 h at $180^{\circ}C$. The bio-based heterogeneous acid catalysts could be used three times without any significant loss of activity. This greener protocol provides highly selective conversion of xylose to furfural as well as facile isolation of product and bio-based heterogeneous acid catalysts can alternate the environmentally-burdened mineral acids.

• Journal of Microbiology and Biotechnology
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• 제32권7호
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• pp.892-901
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• 2022

The rising demand for carotenoids can be met by microbial biosynthesis as a promising alternative to chemical synthesis and plant extraction. Several species of lactic acid bacteria (LAB) specifically produce C₃₀ carotenoids and offer the added probiotic benefit of improved gut health and protection against chronic conditions. In this study, the recently characterized Lactiplantibacillus plantarum subsp. plantarum KCCP11226^T produced the rare C₃₀ carotenoid, 4,4'-diaponeurosporene, and its yield was optimized for industrial production. The one-factor-at-a-time (OFAT) method was used to screen carbon and nitrogen sources, while the abiotic stresses of temperature, pH, and salinity, were evaluated for their effects on 4,4'-diaponeurosporene production. Lactose and beef extract were ideal for optimal carotenoid production at 25℃ incubation in pH 7.0 medium with no salt. The main factors influencing 4,4'-diaponeurosporene yields, namely lactose level, beef extract concentration and initial pH, were enhanced using the Box-Behnken design under response surface methodology (RSM). Compared to commercial MRS medium, there was a 3.3-fold increase in carotenoid production in the optimized conditions of 15% lactose, 8.3% beef extract and initial pH of 6.9, producing a 4,4'-diaponeurosporene concentration of 0.033 A₄₇₀/ml. To substantiate upscaling for industrial application, the optimal aeration rate in a 5 L fermentor was 0.3 vvm. This resulted in a further 3.8-fold increase in 4,4'-diaponeurosporene production, with a concentration of 0.042 A₄₇₀/ml, compared to the flask-scale cultivation in commercial MRS medium. The present work confirms the optimization and scale-up feasibility of enhanced 4,4'-diaponeurosporene production by L. plantarum subsp. plantarum KCCP11226^T.

• Analytical Science and Technology
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• 제37권2호
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• pp.87-97
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• 2024

The appropriate intake of fluoride (F^-) is beneficial to human health; however, the over-consumption can result in various potentially harmful effects. This study compared different colorimetric reagents, i.e., aluminium-xylenol orange (Al-XO), zirconium-xylenol orange (Zr-XO), and zirconium-alizarin red S (Zr-ARS), for fluoride measurements by the UV-Vis, in terms of reaction mechanisms, method sensitivity, and interferences from aluminium and ferric ions. The colorimetric procedures were optimized, and the analytical methods were evaluated. The goodness of linearity (R² > 0.998) was obtained for all three assays within the concentration range of 1.0-20.0 mg/L fluoride in deionized water, in which the method sensitivity followed the descending order of Zr-XO > Al-XO > Zr-ARS. The Zr-XO was applied for determining the fluoride in different tea extracts in water (90 ℃ and 60-minute-brewing) and black tea demonstrated the highest fluoride content (3.0-3.6 mg/L). The effects of brewing time and temperature on the release of fluoride in the tea extracts were also investigated, indicating these are critical factors for the fluoride extraction. This study highlighted the application potentials of the UV-Vis measurement as a simple, convenient, and cheap analytical approach and discussed different colorimetric reagents used for fluoride determination in tea extracts in the context that the UV-Vis spectrophotometers are commonly equipped in most laboratories.

• Food Science of Animal Resources
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• 제30권1호
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• pp.73-86
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• 2010

The current study was designed to optimize solid phase microextraction (SPME)-GC-MS conditions for extraction and analysis of volatile components for Hanwoo beef and to establish a tentative database of flavor components. Samples were taken from Hanwoo longissimus muscle (30 mon old steer, $1^+B$ carcass grade) at 24 h postmortem. Results indicated that the optimum adsorption time for $75{\mu}m$ CAR/PDMS fiber was 60 min at $60^{\circ}C$. Thermal cleaning at $250^{\circ}C$ for 60 min was the best practice for decontamination of the fiber. A short analysis program with a sharp oven temperature ramp resulted in a better resolution and higher number of measurable volatile components. With these conditions, 96 volatile compounds were identified with little variation including 22 aldehydes, 8 ketones, 31 hydrocarbons, 12 alcohols, 8 nitrogen- and sulfurcontaining compounds, 5 pyrazines and 10 furans. A noticeable observation was the high number of hydrocarbons, aldehydes, ketones, alcohols and 2-alkylfurans which were generated from lipid decomposition especially the oxidation and degradation of unsaturated and saturate fatty acids. This implies that these compounds can be candidates for flavor specification of highly marbled beef such as Hanwoo flavor.