• Membrane and Water Treatment
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• v.7 no.1
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• pp.55-70
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• 2016

Microfiltration/ultrafiltration (MF/UF) Adsorptive polyamide-6 (PA-6) membranes were prepared using wet phase inversion process. The prepared PA-6 membranes are characterized by scanning electron microscopy (SEM), porosity and swelling degree. In this study, the membranes performance has examined by adsorptive removal of copper ions from aqueous solutions in a batch adsorption mode. The $PA-6/H_2O$ membranes display sponge like and highly porous structures, with porosities of 41-73%. Under the conditions examined, the adsorption experiments have showed that the $PA-6/H_2O$ membranes had a good adsorption capacity (up to 120-280 mg/g at the initial copper ion concentration ($C_0$) = 680 mg/L, pH7), fast adsorption rates and short adsorption equilibrium times (less than 1.5-2 hrs) for copper ions. The fast adsorption in this study may be attributed to the high porosities and large pore sizes of the $PA-6/H_2O$ membranes, which have facilitated the transport of copper ions to the adsorption. The results obtained from the study illustrated that the copper ions which have adsorbed on the polyamide membranes can be effectively desorbed in an Ethylene dinitrilotetra acetic acid Di sodium salt ($Na_2$ EDTA) solution from initial concentration (up to 92% desorption efficiency) and the PA-6 membranes can be reused almost without loss of the adsorption capacity for copper ions. The results obtained from the study suggested that the $PA-6/H_2O$ membranes can be effectively applied for the adsorptive removal of copper ions from aqueous solutions.

• Journal of the Korea Concrete Institute
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• v.13 no.4
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• pp.397-405
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• 2001

In clod weather regions, a strong seasonal wind brings sea salts to the land. In addition to it, recently, the spreading amount of deicing salts has increased numerously for purpose of removing snow and ice. Thus the salts environment around concrete structures becomes so severe that various damages of concrete due to applied salts will be brought up. Much of countries such as America, Europe etc. is carried out study for effects of deicing salts on concrete. However, there are not test methods for deterioration of concrete subjected to both freezing-thawing and chloride in Korea. In this study, we carried out test for the compound deterioration subjected to both freezing-thawing and chloride attack, to investigate the effects of sodium chloride on the deterioration of concrete. The test was performed to investigate the effects of cement type, strength and air content on the scaling deterioration of concrete. As a result, the scaling deterioration was accelerated in the presence of salts. And the resistance to scaling was strongly influenced by the type of cement, the strength and air content of concrete.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3653-3659
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• 2015

This paper describes the reactive compatibilization of blends of a wholly aromatic thermotropic copolyester liquid crystalline polymer (TLCP) with random copolymers of ethylene and acrylic acid (EAA) and their salts. Blends were prepared by melt mixing in an intensive batch mixer, and the formation of a graft copolymer due to acidolysis between the TLCP and the acrylic acid group of the ionomer was evaluated. Chemical reaction was assessed by torque measurement during melt mixing and by thermal analysis and morphological observation. The Na-salt of the EAA ionomers was especially effective at promoting a grafting reaction. The extent of reaction depended not only on the cation, but also composition of the ionomer and reaction time. The product of the grafting reaction between the TLCP and a sodium-neutralized ionomer proved to be an effective compatibilizer for TLCP and EAA ionomers.

• Tribology and Lubricants
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• v.30 no.6
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• pp.323-329
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• 2014

The friction-reducing properties of lubricants containing ionic liquids based on ammonium dithiocarbamate are studied. The ionic liquids are produced through the following two steps: the synthesis of sodium alkyl dithiocarbamates via the substitution reaction of dialkylamine and carbon disulfide and their subsequent conversion into ammonium dithiocarbamate-based ionic liquids through an ion-exchange reaction with a quaternary alkyl ammonium halide salt. The structures of the ionic liquids are characterized by NMR spectroscopy and Fourier transform infrared spectroscopy. The isolated yields of the ionic liquids, which are viscous and pale yellow, are approximately 92%. The Brookfield viscosities and pour points of the ionic liquids are determined. Further, their wear resistances are measured through the four-ball wear test and the Schwingung Reibung Ver-schleiss (oscillation, friction, wear) test. The wear scar diameter of the lubricants containing 1 wt of the quaternary alkyl ammonium dithiocarbamate-based ionic liquids (0.475-0.631 mm) is significantly lower than that of the base oil (0.825 mm), proving that the ammonium dithiocarbamate-based ionic liquids have good friction-reducing characteristics. However, these friction-reducing characteristics fade significantly after long-term storage, owing to the degradation of the ionic liquids.

• Korean Journal of Medicinal Crop Science
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• v.25 no.4
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• pp.244-251
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• 2017

Background: The application of crop rotation systems may reduce the occurrence of soil-borne diseases by releasing allelochemicals and by subsequent microbial decomposition. Methods and Results: For reduction of ginseng root rot by the crop rotation system, after harvesting 6-year-old ginseng, fresh ginseng was grown along with continuous cultivation of sweet potato, peanut, and bellflower. Growth of 2-year-old ginseng was significantly inhibited in the continuous cultivation than in the first cultivation. Sweet potato, peanut and bellflower cultivations assisted in obtaining normal yields of ginseng in the first year after the harvest of 6-year-old ginseng. Salt concentration, potassium and sodium contents were gradually decreased, and, organic matter was gradually increased through cirp rotation. Phosphate, calcium and magnesium contents were not altered. The density of the root rot fungus was gradually decreased by the increase in crop rotation; however it was decreased distinctly in the first year compared to the second and third year. The severity of root rot disease tended to decrease gradually by the increase of crop rotation. Conclusions: Short-term crop rotation for three years promoted the growth of ginseng, however root rot infection was not inhibited significantly, although it was somewhat effective in lowering the density of the root rot pathogen.

• Childhood Kidney Diseases
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• v.20 no.1
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• pp.11-17
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• 2016

Appropriate control of diet and water intake is important for maintaining normal blood pressure, fluid and electrolyte homeostasis in the body. It is relatively understood that the amount of sodium and potassium intake directly affects blood pressure and regulates ion transporters; Na and K channel functions in the kidney. However, little is known about whether diet and water intake regulates Aquaporin (AQP) function. AQPs, a family of aquaporin proteins with different types being expressed in different tissues, are important for water absorption by the cell. Water reabsorption is a passive process driven by osmotic gradient and water permeability is critical for this process. In most of the nephron, however, water reabsorption is unregulated and coupled to solute reabsorption, such as AQP1 mediated water absorption in the proximal tubule. AQP2 is the only water channel founded so far that can be regulated by hormones in the kidney. AQP2 expressed in the apical membrane of the principal cells in the collecting tubule can be regulated by vasopressin (antidiuretic hormone) controlling the final volume of urine excretion. When vasopressin binds to its receptor on the collecting duct cells, it stimulates the translocation of AQP2 to the membrane, leading to increased water absorption via this AQP2 water channel. However, some studies also indicated that the AQP2 is also been regulated by vasopressin independent mechanism. This review is focused on the regulation of AQP2 by diet and the amount of water intake on salt and water homeostasis.

• Food Science of Animal Resources
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• v.39 no.5
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• pp.844-861
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• 2019

Over the last few years, marine environment was found to be a source of surplus natural products and microorganisms with new bioactive secondary metabolites of interest which can divulge nutritional and biological impact on the host. This study aims to assess the possible, inherent and functional probiotic properties of a novel probiotic strain Enterococcus durans F3 (E. durans F3) isolated from the gut of fresh water fish Catla catla. Parameters for evaluating and describing the probiotics described in FAD/WHO guidelines were followed. E. durans F3 demonstrated affirmative results including simulated bile, acid and gastric juice tolerance with exhibited significant bactericidal effect against pathogens Staphylococcus aureus, Salmonella Typhi, Escherichia coli and Pseudomonas aeruginosa. This can be due to the enterocin produced by E. durans F3 strain, which was resolute by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) gel with amplification of the anticipated fragment of a structural gene; enterocin A, followed by antibiotic susceptibility assessment. Effective antioxidant potentiality against ${\alpha}$-diphenyl-${\alpha}$-picrylhydrazyl free radicals including lipase, bile salt hydrolase activity with auto-aggregation and cell surface hydrophobicity was similarly observed. Results are proving the potentiality of E. durans F3, which can also be used as probiotic starter culture in dairy industries for manufacturing new products that imparts health benefits to the host. Finding the potent and novel probiotic strains will also satisfy the current developing market demand for probiotics.

• Nutrition Research and Practice
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• v.13 no.6
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• pp.509-520
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• 2019

BACKGROUND/OBJECTIVES: This study evaluated whether a mobile health (mHealth) application can instigate healthy behavioral changes and improvements in metabolic disorders in individuals with metabolic abnormalities. SUBJECTS/METHODS: Participants were divided into an mHealth intervention group (IG), which used a mobile app for 24 weeks, and a conventional IG. All mobile apps featured activity monitors, with blood pressure and glucose monitors, and body-composition measuring devices. The two groups were compared after 24 weeks in terms of health-behavior practice rate and changes in the proportion of people with health risks, and health behaviors performed by the IG that contributed to reductions in more than one health risk factor were analyzed using multiple logistic regression. RESULTS: Preference for low-sodium diet, reading nutritional facts, having breakfast, and performing moderate physical activity significantly increased in the mHealth IG. Furthermore, the mHealth IG showed a significant increase of eight items in the mini-dietary assessment; particularly, the items "I eat at least two types of vegetables of various colors at every meal" and "I consume dairies, such as milk, yogurt, and cheese, every day." The proportion of people with health risks, with the exception of fasting glucose, significantly decreased in the mHealth IG, while only the proportion of people with at-risk triglycerides and waist circumference of females significantly decreased in the control group. Finally, compared to those who did not show improvements of health risks, those who showed improvements of health risks in the mHealth IG had an odds ratio of 1.61 for moderate to vigorous physical activity, 1.65 for "I do not add more salt or soy sauce in my food," and 1.77 for "I remove fat in my meat before eating." CONCLUSIONS: The findings suggest that the additional use of a community-based mHealth service through a mobile application is effective for improving health behaviors and lowering metabolic risks in Koreans.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1433-1441
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• 2018

The development of acidosis during intense exercise has traditionally been explained by the increased production of lactic acid which causes the release of a proton and the formation of the acid salt sodium lactate. Through this explanation, when the rate of lactate production is high enough to exceed cellular proton buffering capacity, cellular pH is decreased. This biochemical process has been termed lactic acidosis. This belief has been an interpretation that lactate production causes acidosis and fatigue during intense exercise. However, this review provides clear evidence that there is no biochemical support for lactate production causing acidosis and fatigue. Metabolic acidosis is caused by an increased reliance on nonmitochondrial ATP turnover. Lactate production is essential for muscle to produce cytosolic $NAD^+$ to support continued ATP regeneration from glycolysis. In addition, Lactate production consumes protons. Although lactate accumulation can be a good indirect indicator for decreased cellular and blood pH, that is not direct causing acidosis.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.6
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• pp.559-572
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• 2018

The aim of this study was to evaluate pretreatment methods for 27 pharmaceuticals and personal care products (PPCPs) in various sewage samples using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) and online solid-phase extraction with LC-MS/MS. Extraction efficiencies of PPCPs in the solid phase under different experimental conditions were evaluated, showing that the highest recoveries were obtained with the addition of sodium sulfate and ethylenediaminetetraacetic acid disodium salt dehydrate in acidified conditions. The recoveries of target compounds ranged from 91 to 117.2% for liquid samples and from 61.3 to 137.2% for solid samples, with a good precision. The methods under development were applied to sewage samples collected in two sewage treatment plants (STPs) to determine PPCPs in liquid and solid phases. Out of 27 PPCPs, more than 19 compounds were detected in liquid samples (i.e., influent and effluent) of two STPs, with concentration ranges of LOQ-33,152 ng/L in influents and LOQ-4,523 ng/L in effluents, respectively. In addition, some PPCPs such as acetylsalicylic acid, ibuprofen, and ofloxacin were detected at high concentrations in activated sludge as well as in excess sludge. This methodology was successfully applied to sewage samples for the determination of the target compounds in STPs.