• Resources Recycling
• /
• v.33 no.3
• /
• pp.3-11
• /
• 2024

This study addressed the cost structure of metallurgical plants for vanadium recovery or production, which were previously planned or implemented. Vanadium metallurgy consists of several sub-processes such as such as pretreatment, roasting, leaching, precipitation, and filtration, in order to finally produce vanadium pentoxide. Here, lots of costs should be spent for such plants, in which these costs are largely divided into CAPEX (Capital Expenditure) and OPEX (Operational Expenditure). As a result, the capacities (feed input rates) and vanadium contents are various along the target projects for this study. However, final production rates and grades of vanadium pentoxide showed relatively small differences. In addition, a noticeable correlation is found between capacities and specific operating costs, in that a steadily decreasing trend is described with a non-linear curve with around -0.3 power. Therefore, for the plant capacity below 100,000 tons per year, the specific operating cost rapidly decreases as the capacity increases, whereas the cost remains relatively stable in the range of 0.6 to 1.2 million tons per year of the capacity. From a technical perspective, effective optimization of the metallurgical process plant can be achieved by improving vanadium recovery rate in the pre-treatment and/or roasting-leaching processes. Finally, the results of this study should be updated through future research with on-going field verification and further detailed cost analysis.

• Korean Circulation Journal
• /
• v.54 no.9
• /
• pp.549-561
• /
• 2024

Background and Objectives: The efficacy of sodium-glucose cotransporter-2 inhibitors (SGLT2i) may depend on renal function, and this raises theoretical concern over its effects on cardiovascular outcomes in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD). Methods: This systematic review and updated meta-analysis of randomized controlled trials (RCTs) compared cardiovascular outcomes of patients with T2DM and CKD treated with SGLT2i to placebo. PubMed, Embase, and Cochrane were systematically searched. Prespecified subgroup analyses were performed in strata of estimated glomerular filtration rate (eGFR) of <45 mL/min/1.73 m² and 45 to 59 mL/min/1.73 m². Results: Nine RCTs comprising 29,146 patients were selected. Average follow-up ranged from 0.75 to 4.2 years. SGLT2i were shown to reduce the risk of all-cause mortality (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.79-0.97; p=0.01), the composite of cardiovascular mortality or hospitalizations for heart failure (HHF: HR, 0.71; 95% CI, 0.65-0.78; p<0.001), cardiovascular mortality (HR, 0.86; 95% CI, 0.76-0.98; p=0.02), HHF (HR, 0.62; 95% CI, 0.55-0.71; p<0.001), major adverse cardiovascular events (HR, 0.85; 95% CI, 0.77-0.94; p=0.002), stroke (HR, 0.76; 95% CI, 0.59-0.97; p=0.03), and myocardial infarction (HR, 0.78; 95% CI, 0.67-0.91; p=0.001). These findings were consistent over strata of eGFR, albeit with a lower incidence of stroke in patients treated with SGLT2i with eGFR <45 mL/min/1.73 m² (p-value for interaction=0.04). Conclusions: Compared with a placebo, patients with T2DM and CKD treated with SGLT2i experience a reduction in all-cause mortality, cardiovascular mortality, and HHF.

• Journal of Radiation Industry
• /
• v.18 no.3
• /
• pp.167-171
• /
• 2024

Technetium-99 (⁹⁹Tc) is recognized as a critical concern in the disposal of spent nuclear fuel due to its long half-life and remarkable stability, existing predominantly as TcO₄^- in the natural environment. The anionic form of technetium is highly soluble and mobile, posing significant environmental risks from the viewpoint of nuclear waste management. Thus, developing efficient and cost-effective sorbents for aqueous Tc(VII) is essential for mitigating relevant contamination. In the present work, the adsorption characteristics of Re(VII), a chemical analog of Tc(VII), were investigated using the clay mineral bentonite, modified with two different organic cations: hexadecylpyridinium (HDPy) and hexadecyltrimethylammonium (HDTMA). Sorption experiments were conducted at a liquid-to-solid ratio of 1 g/L with Re(VII) solutions prepared at concentrations from 10^-4 mol/L to 10^-6 mol/L. The sorption ratio and distribution coefficients were determined with samples collected at reaction times of 10, 50, 100, and 500 minutes after 0.45 ㎛ syringe filtration. In parallel, the modified bentonite samples were further analyzed using the X-ray diffraction (XRD) method to understand the adsorption mechanism of Re(VII) onto the target minerals. According to the quantification analysis results, a rapid equilibrium reaction of aqueous Re(VII) for all modified bentonite samples was identified. Moreover, near-complete adsorption of Re(VII) was observed when the bentonite was modified at 200-400% of its cation exchange capacity (CEC) for both organic cations. For cases of lower modification, the HDTMA-modified bentonite showed relatively higher adsorption efficiency compared with the one modified with HDPy. This result was inferred to be due to the difference in inter-layer spacing based on the characteristics of the organic cations. It is expected that the results obtained through this study will serve as a preliminary case for the synthesis of adsorbents for the retardation of highly mobile anionic radionuclides, such as I and Tc, in the natural environment.

• Korean Journal of Food Science and Technology
• /
• v.48 no.3
• /
• pp.268-274
• /
• 2016

The purpose of this study was to investigate the immuno-stimulatory activity of the high-molecular-weight fraction (HMWF) of Cynanchum wilfordii (CW) extracts obtained by ultrafiltration in murine macrophage RAW 264.7 cells and to assess its immuno-stimulatory effect in mice. Ultrafiltration was performed with polyethersulfone membranes (30 kDa cutoff) in a cross-flow filtration system to obtain the HMWF of CW. The results showed that the HMWF increased the production of various cytokines such as tumor necrosis factor-${\alpha}$, interleukin-6, and nitric oxide in dose-ependent manners. In addition, HMWF treatment increased the relative spleen weight as well as splenocyte proliferation induced by concanavalin A or bacterial lipopolysaccharide in mice. Natural killer (NK) cell activity in the HMWF-treated group was significantly increased compared to that in the control group. These results suggest that the HMWF of CW can support the immune system through secretion of macrophage cytokines, thereby enhancing NK cell activity and murine splenocyte proliferation.

• Clinical and Experimental Pediatrics
• /
• v.46 no.2
• /
• pp.173-177
• /
• 2003

Purpose : Recently, different results about factors affecting accurate quantitation of 24-hr urinary protein(24UP) amount using spot urine protein/creatinine ratio(PCR) have been reported. The current study was designed to evaluate correlation between 24UP amounts and PCR in children, and the effect of 24UP amounts, age, sex, and glomerular filtration rate(GFR) on this correlation. Methods : Among 94 patients who visited the department of pediatrics in Busan Paik Hospital from March 2002 to August 2002, 68 patients whose urinary creatinine excretion was ${\geq}15mg/kg/day$ were included in this study. All the patients were divided into I, II/A, B group(I : 24UP<500 mg/day, II : $24UP{\geq}500mg/day$, A : <10 years of age, B : ${\geq}10years$ of age). Pearson correlation analysis was performed between 24UP and PCR to evaluate the relationship. We defined fractional difference between 24UP and PCR, and then performed multiple regression analysis with 24UP amount, age, GFR and fractional difference. Results : There was a strong positive linear correlation between 24UP and PCR(R=0.936, P<0.0001) in all patients, and the correlation was also good in each group. Using PCR cutoff values of 0.5, the PCR provided high sensitivity, specificity, positive and negative predictive value in predicting 24UP amount ${\geq}500mg$. The factors affecting accurate quantitation of proteinuria using spot urine PCR was age, not 24UP amount, GFR or sex. Conclusion : Spot urine PCR is a useful test but has limitations in predicting 24UP amount. Therefore, it should be used only as screening method. Age-adjusted PCR cutoff values may be necessary to predict 24UP amount in children with proteinuria.

• Journal of Nutrition and Health
• /
• v.36 no.1
• /
• pp.9-17
• /
• 2003

The preparation method of a soluble dietary fiber from oak wood (Quercus mongolica) and the effect of the soluble dietary fiber on physiological function in rat fed high cholesterol diets was investigated. The best condition for steam explosion method was 25 kgf/㎤ pressure for 6 min. The exploded samples were delignified by the filtration treatment with 1% NaOH for several times, which is the best condition. The enzymatic hydrolysis of Cellusoft cellulase was more effective than Onozuka R-10 cellulase. The manufactured soluble dietary fiber was assayed using gel permeation chromatography (GPC) and it was dissolved in water. Average molecular weight distribution of manufactured soluble dietary fiber was about 348-1,200 and it was assumed the oligomer form fraction. In order to compare the manufactured soluble dietary fiber with commercial soluble dietary fiber (pectin) on the physiological function, Sprague-Dawley male rats weighing 100$\pm$10 g were randomly assigned to one normal diet and five high cholesterol diet containing 1% cholesterol. The high cholesterol diet groups were classified to fiber free diet (FF group), 5% pectin (5P group), 10% pectin (l0P group), 5% manufactured soluble dietary fiber (5M group) and 10% manufactured soluble dietary fiber (10M group). Body weight gains in all soluble dietary fiber groups were lower than FF group. Food intakes were increased in all soluble dietary fiber groups than that of FF group. Food efficiency ratio (FER) was significantly decreased in all soluble dietary fiber groups than that of the FF group, and it was especially was highest in 10% supplemented soluble dietary fiber group. The weight of liver of the soluble dietary fiber supplemented groups were lower than those of the FF group, but weights of cecum and small intestine of all supplemented soluble dietary fiber groups were significantly increased, compared with that of FF group. The weights and water contents in feces were significantly increased by the soluble dietary fiber. The activity of the glutamic oxaloacetic transaminase in soluble dietary fiber groups were significantly decreased than those of FF group. The hepatic glutathione S-transferase activity in all soluble dietary fiber supplemented groups were higher than that of FF group. The physiological effects of the manufactured soluble dietary fiber are the same as the commercial soluble dietary fiber (pectin). The preparation method of the soluble dietary fiber from the oak chips suited to its purpose. (Korean J Nutrition 36(1) : 9~17, 2003)

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.4
• /
• pp.547-557
• /
• 1996

Background : An excessive accumulation of neutrophils in lung tissue has been known to play an important role in mediating the tissue injury among the adult respiratory distress syndrome, idiopathic pulmonary fibrosis and cystic fibrosis by releasing toxic oxygen radicals and proteolytic enzymes. Therefore, it is important to understand a possible mechanism of neutrophil accumulation in lung tissue. In many species, exposure to hyperoxic stimuli can cause changes of lung tissues very similar to human adult respiratory distress syndrome and neutrophils are also functioning as the main effector cells in hyperoxic lung injury. The purpose of the present study was to examine whether neutrophils function as a key effector cell and to study the nature of possible neutrophil chemotactic factors found in bronchoalveolar lavage fluid from the hyperoxia exposed rats. Methods : We exposed the rats to the more than 95% oxygen for 24, 48, 60 arid 72 hours and bronchoalveolar lavage(BAL) was performed. Neutrophil chemotactic activity was measured from the BAT- fluid of each experimental groups. We also evaluated the molecular weight of neutrophil chemotactic tractors using fast performance liquid chromatography and characterized the substances by dialyzer membrane and heat treatment. Results : 1) The neutrophil proportions in bronchoalveolar lavage fluid began to rise from 48 hours after oxygen exposure, and continued to be significantly increased with exposure times. 2) chemotactic index for neutrophils in lung lavages from rats exposed to hyperoxia was significantly higher in 48 hours group than in control group, and was significantly increased with exposure time. 3) No deaths occured until after 48 hours of exposure. However, mortality rates were increased to 33.3 % in 60 hours group and 81.3 % in 72 fours group. 4) Gel filtration using fast performance liquid chromatography disclosed two peaks of neutrophil chemotactic activity in molecular weight of 104,000 and 12,000 daltons. 5) Chemotactic indices of bronchoalveolar lavage fluid were significantly deceased when bronchoalveolar lavage fluid was treated with heat ($56^{\circ}C$ for 30 min or $100^{\circ}C$ for 10 min) or dialyzed (dialyzer membrane molecular weight cut off : 12,000 daltons). Conclusion : These results suggested that the generation of neutrophil chemotactic factor and subsequent neutrophil influx into the lungs are playing an important roles in hyperoxia-induced acute lung injury. Neutrophil chemotactic factor in the lung lavage fluids consisted of several distinct components having different molecular weight and different physical characteristics.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.4
• /
• pp.506-512
• /
• 2003

Peach wine was fermented at $25^{\circ}C$ for 2 weeks using Saccharomyces cerevisiae KCCM 12224, aged at 15$^{\circ}C$ for 14 weeks, and its physicochemical and microbiological changes were investigated. The viable bacterial cell numbers, 1.4$\times$10$^3$ CFU/mL at the beginning of fermentation, increased to 2.8$\times$10$^{6}$ CFU/mL after 2 weeks, but decreased to 7.0$\times$10$^3$ CFU/mL after 14 weeks. The viable yeast cell numbers were changed from 3.4$\times$10$^2$ CFU/mL to 2.4$\times$10$^{7}$ CFU/mL during fermentation, and decreased to 4.0$\times$10$^4$ CFU/mL after aging. Turbidity total sugar content, reducing sugar content, solid content and b value of peach wine decreased during fermentation but acidity, alcohol content, L and a value increased. Most physicochemical properties except alcohol content and reducing sugar content were not changed significantly during aging. When peach wine was filtered through 0.45 ${\mu}{\textrm}{m}$ nitrocellulose membrane followed by various ultrafiltration membranes with different molecular weight cut-off values, Biomax 100K membrane, with 79 liter/$m^2$/h (LMH) of initial flux, was suitable for ultrafiltration process of peach wine. These membrane filtration treatments resulted in complete removal of microorganisms and decrease in turbidity and alcohol content without changes in other chemical properties. The physicochemical properties of peach wine were not changed and any microorganisms were not found during the storage at 3$0^{\circ}C$ for 12 Weeks.

• Journal of Korean Society of Forest Science
• /
• v.45 no.1
• /
• pp.62-67
• /
• 1979

Ultraviolet microscopy of ultrathin sections of wood has proved to be one of the useful means for determining the lignin distribution in the various regions of the cell wall. Also, spectral approach and quantitative analysis of isolated compound middle lamella fraction from birch xylem have revealed that the lignin associated with the vessel secondary wall and middle lamella is composed predominantly of gualacylpropane units. Lignin deposited in the fiber and ray parenchyma secondary walls is composed mostly of syringylpropane units. The middle lamella lignin around fibers and ray cells contains both guaiacyl and syringyl propane quits. On the basis of the results above, this research was carried out to clarify the origin of milled wood lignin (MWL) by analysing the chemical characteristics of ML MWLs extracted at various milling stages. The amount of phenolic hydroxyl-, ${\alpha}$-carbonyl-, and methoxyl-group in the MWL's increases the milling time. And progressive mining contributes to the merease of ratio of syringylaldehyde to vanillin(S/V ratio) after nitrobenzene oxidation of MWL. Accordingly, It could be concluded that milled wood lignin extracted at the initial milling stage derives from compound middle lamella region of cell wall, whereas, with progressive milling, lignin of secondary wall of fiber is introduced gradually to milled wood lignin. These results are suggesting that heterogeneous chemical structure of lignins in hardwood exists. Although milled wood lignin at the initial stage seems to have lower molecular weight in comparison with milled wood lignin extracted at final milling stage from the result of Gel-filtration curves, further study would be required on molecular weight distribution of milled wood lignin in future.

• Journal of Korean Society of Forest Science
• /
• v.81 no.2
• /
• pp.164-176
• /
• 1992

This study was conducted to determine the toxic effects of air pollutants on landscaping trees, Pinus densiflora, Pinus koraierasis, Ginkgo biloba, Liriodeytdron tulipifera, Platanus occidentalis and their resistance to the pollutant toxicity in urban and industrial regions of Seoul and Taejon, Korea. Total sulfur content and superoxide dismutase activity were analysed in tree foliage of Pinus densiflora, Pinzes koraiensis, Ginkgo biloba, Liriodendron tulipifera, Platanus occidentalis. In addition, SOD activity was analyzed in the foliage of tree seedlings, i.e. Pinus densijlora, Pinus koraiensis, Ginkgo biloba, Liriodendron tulipifera, with the lurnigation of $SO_2$ in gas chamber 4 hours a day for six days. In all species total sulfur content and SOD activity had a positive correlation. Air pollutants accumulated in tree tissues were supposed to enhance the enzyme activity like SOD providing with the resistance mechanisms. Trees under the air pollution stress increased enzyme activity to develop internal self-resistance against pollutants, but after a critical point enzyme-activity decreased gradually and resulting in injury after all, Deciduous trees had greater filtration capacity than conifers and coniferous trees showed greater resistance against air pollutants than deciduous species. Foliage SOD activity was higher in polluted area than in unpolluted area for most species. Coniferous species and mature trees had higher SOD activity than deciduous seedlings. Especially Pinus koraiensis, Ginkgo biloba and Plcatanus occidentalis had higher SOD activity than other species. The tree species with the high SOD activity showed strong resistance against air pollutants. In 2nd-year needles of Pinus densiflora seedlings and current and 2nd-year needles of Pinus koraiensis seedlings containing high native SOD activity, SOD activity increased with the increase of $SO_2$ level. But in seedlings containing low native SOD activity, SOD activity increased at 0.5ppm $SO_2$ level while it decreased at 1.5 and 2.5ppm $SO_2$. Changes of SOD activity was different between species and in most species SOD seemed to participate in resistance mechanism.