• KSBB Journal
• /
• v.24 no.1
• /
• pp.17-24
• /
• 2009

For the biosurfactant production process at first Candida bombicola, Sphingomonas yanoikuyae, Sphingomonas chungbukensis and Myxococcus flavescens were studied. As the most productive microorganisms C. bombicola, S. yanoikuyae and S. chungbukensis were selected. During many petrochemical industrial processes variable volatile organic componds are produced and they can cause an unpleasent and unhealthy atmosphere. Usually the volatile organic compounds are treated with chemical detergents. The chemical detergents cannot be easily degradable and can be accumulated in the nature. In this study we tried to develop a production process for the biosurfactants, which can substitute some chemical detergents in some chemical processes, with microorganisms. At second the treatment of the volatile organic compounds with the biosurfactants were tested and compared with the treatment with chemical detergent. The production productivities of the biosurfactant with microorganisms were compared. The growth patterns and kinetics of the microbial cells and the surface tension values of the biosurfactants were studied. The changes of the surface tension in variable pH conditions and sodium chloride concentrations were also studied. The volatile organic carbons were treated in a small plant scale. As the result of this study, it indicated that the specific growth rate of S. chungbukensis was the fastest by 0.144 ($hr^{-1}$). For surface tension, C. bombicola (38.1 dyne/cm) had the lowest value, and solubility of the volatile organic carbon was similar in C. bombicola and S. chungbukensis. (Toluene: about 0.1 Unit, Chloroform: about 0.6${\sim}$0.7 Unit, Benzene: about 0.5${\sim}$0.8 Unit). The biosurfactant, which were produced by C. bombicola, was selected for the further study for the volatile organic carbon treatment. With the biosurfactans from C. bombicola could remove the volatile organic carbon about 80% and this removal rate can be comparable with chemical detergent.

• Journal of Environmental Health Sciences
• /
• v.36 no.4
• /
• pp.337-341
• /
• 2010

The modified simultaneous differential staining technique, which enables double staining of cartilage and bones, needs to be improved to prevent soft tissues from being damaged during the staining process. Key factors influencing the extent to which soft tissues are damaged include the fixative used, macerating time, potassium hydroxide concentration, incubation temperature and the removal of skin from specimens. Here we describe a protocol that enables the hardening of tissues during bleaching and maceration. We also describe a method for objectively measuring rates of cartilage and bone growth. The use of formalin as a fixative rendered soft tissues more rigid due to the resulting chemical bonds formed between proteins. Blotted specimens were immersed in 1% potassium hydroxide (KOH) and incubated at $37^{\circ}C$ for 1 day (smaller specimens) or 2-3 days (larger specimens). The 1% KOH solution was also used as the diluent solution for the subsequent immersion in a graded series of 30%, 50%, 70%, 90%, 100% glycerol solutions, a procedure that made soft tissues even more transparent and hardened. It was not necessary to remove the skin of specimens shorter than 2 cm, since the macerating solution could easily penetrate their thin skin layer and continuously remove those pigments hindering visibility. Since excessive osmosis is another factor that can damage soft tissues in the macerating process by causing the rupture of those cells not able to withstand the osmotic pressure, here it was minimized by balancing the salt concentration between the interior and exterior of cells with the addition of 0.9% sodium chloride (NaCl) in the macerating solution. Finally, to determine the proportions of cartilage and bone growth, photographs of the stained specimens were taken with a dissecting microscope and sections corresponding to the cartilage and bones were cut out from the printed pictures and weighed. Our results show that this method is suitable for the objective evaluation of bone and cartilage growth.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• v.10 no.S_2
• /
• pp.79-88
• /
• 2001

Humic acids react with chlorine to produce Trihalomethanes(THMs), known as carcinogens, during disinfection, the last stage in water purification. Currently, the removal of organic humic acids is considered the best approach to solve the problem of THM formation. Accordingly, the current study examined the adsorption of organic compounds of humic acids onto an inorganic carrier prepared from oyster shell waste. The adsorbent used was activated oyster shell powder(HAP) and silver ion-exchanged oyster shell powder(HAP-Ag), with CaCO$_3$ as the control. The adsorbates were phthalic acid, chelidamic acid, catechol, dodecylpyridinium chloride(DP), and 2-ethyl phenol(2-EP). The adsorption experiments were carried out in a batch shaker at $25^{\circ}C$ for 15 hours. The equilibrium concentration of the adsorbate solution was analyzed using a UV spectrophotometer and the data fitted to the Langmuir isotherm model. Since the solution pH values were found to be greater than the pKa values of the organic compounds used as adsorbates, the compounds apparently existed in ionic form. The adsorptive affinities of the organic acid and phenolic compounds varied depending on the interaction of electrostatic forces, ion exchange, and chelation. More carboxylic acids and catechol, rather than DP and 2-EP, were adsorbed onto HAP and HAP-Ag. HAP and HAP-Ag exhibited a greater adsorptive affinity for the organic compounds than CaCO$_3$, used as the control.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.2
• /
• pp.341-347
• /
• 1992

Eggs used in this study were obtained from Saudi Arabian Baladi laying hens which were divided into four experimental groups and subjected to the following treatments: Commercial laying ration (17% CP, 3.6% Ca and 0.343%, available P) fed ad libitum as a control (C); Conventional force molting, feed removal for 10 days followed by 18 days full-feed of cracked corn (F); 15 days ad libitum intake of the control ration supplemented, to initiate forced-molt, with 0.35% aluminum as the sulfate (ALS) or the chloride (ALC). The hens were in production for 52 weeks and 17 months of age at the start of the trial and the post-treatment period lasted 36 weeks. During the treatment period F and AL treated groups had similar egg and shell weight, egg surface area, shell thickness and shell weight per unit of surface area but significantly (p<0.05) lower than the control. F had significantly (p<0.05) the highest and the control the lowest Haugh unit values whereas AL fed groups had significantly (p<0.05) lower meat spot incidence compared with the control which tended to have higher value than F group. ALC and F had significantly (p<0.05) the lowest yolk color grade whereas ALC had significantly (p<0.05) lower egg index than ALS and the control. During the post-treatment period the control had significantly (p<0.05) the highest egg index and blood spots incidence and ALS the lowest shell diensity compared with other groups. ALS had significantly (p<0.05) lower shell weight than ALC and the control whereas F and AL treated hens had significantly (p<0.05) the highest Haugh unit values and yolk color grades respectively. F had significantly (p<0.05) lower meat spots incidence than ALC and the control. The same results were observed for ALS compared with the control.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.5
• /
• pp.47-54
• /
• 2018

Concrete undergoes various deterioration on surface. Impregnant with silicate is usually applied to concrete surface and forms insoluble hydrates, which can provide many engineering advantages. In the work, concrete impregnated with colloidal silicate is used for durability enhancement in surface and self-clearing performance is evaluated with photocatalyst-$TiO_2$ spraying. For the work, various tests are performed both for strength evaluation and durability evaluation such as absorption ratio, drying shrinkage, chloride penetration, sulfate resistance, and freezing/ thawing action. Furthermore, removal and self-clearing performance are evaluated with Acetaldehyde decomposition and Methylene blue decolorization. Through silicate impregnation and photocatalyst spraying, the impregnated concrete can have not only durability enhance but also self-clearing performance.

• Korean Journal of Veterinary Research
• /
• v.44 no.3
• /
• pp.389-397
• /
• 2004

The therapeutic efficacy of xylamine in the field of psychological medicine has been recognized for years and the drug is used to treat depression and some other conditions, but little is known about its mechanism of action on vascular system. Therefore, the present study was designed to investigate the influence of xylamine on the contractile responses of isolated rat thoracic arteries to phenylephrine(PE) and potassium chloride(KCl). Xylamine produced a concentration-dependent relaxation in PE-precontracted endothelium intact(+E) rat aortic rings, but not in a KCl-precontracted aortic rings. Also, xylamine inhibited the PE-induced contraction in concentration-dependent manner, but not in the high KCl-induced contraction in +E rings. This concentration-dependent inhibition was suppressed by the removal of the endothelium (-E). The inhibitory effects of xylamine($0.3{\mu}M$) on the PE-induced contractions were suppressed by N(G)-nitro-L-arginine(L-NNA), N(omega)-nitro-L-arginine methyl ester(L-NAME), aminoguanidine, dexamethasone, methylene blue, 1H-[1,2,4]oxadiazolo [4,3-a]quinoxalin-1-one(ODQ), indomethacin, ryanodine, tetrabutylammonium(TBA), lidocaine, procaine and 0 mM extracellular $Na^+$, but not by 2-nitro-4-carboxyphenyl-n,n-diphenylcarbamate(NCDC), lithium, nifedipine, verapamil, 0 mM extracellular $Ca^{2+}$, glibenclamide and clotrimazole. These findings suggest that xylamine could act as a vasorelaxant and direct inhibitor of arterial contraction. This vasorelaxation involves an endothelial nitric oxide (NO)/cGMP (guanosine 3',5'-cyclic monophosphate) pathway or cyclooxygenase system, and an interference with $Ca^{2+}$ release, TBA-sensitive $Ca^{2+}$-activated $K^+$ channels and $Na^+$$ channels.

• Journal of Korean Society of Water and Wastewater
• /
• v.18 no.2
• /
• pp.254-269
• /
• 2004

Polysilicato-iron coagulant (PSI) is receiving attention in Japan as a substitute for aluminum-based coagulants. In the first part of this article, coagulation, sedimentation and filtration experiments were carried out using kaolin clay particles as the turbidizing material and four types of PSI with various molar ratios of polysilicic acid to ferric chloride (Si/Fe ratio). Results demonstrate that use of a PSI with a high Si/Fe ratio can cause a more dramatic decrease in treated water turbidity but a higher suction time ratio (STR) than when PACl is used. However, optimization by increasing the rapid agitation strength GR is found to greatly improve the STR. In addition, the series of filtration experiments verified that optimization of GR is greatly effective in controlling rapid increases in filter head loss, and also formation of a thin aging layer in the upper part of the filter bed by slow-start filtration is effective in improving filtered water turbidity over the entire filtration process. The second part of this article describes two innovative filtration techniques to increase the particle separation efficiency; (1) coagulant-coated filter medium by enhancing the electrical potential of the surface of the filter medium, and (2) coagulant dosing in influent by controlling the electrical potential of particles entering the filter layer. From the results of the various filtration experiments using a pilot plant, these two techniques were found to be very effective to reduce the effluent water turbidity from the start to the end of a filter run. Moreover, in the filtration experiments using these two methods simultaneously, higher removal efficiency of approximately 3-log (99.7%) was realized, resulting that the finished water turbidity was accordingly reduced to 0.004mg/L.

• Membrane Journal
• /
• v.17 no.4
• /
• pp.375-380
• /
• 2007

To recover sericin protein from by-product in silk production process, a polyethersulfone hollow fiber ultra-filtration membrane module was used. The soap in the degummed solution was precipitated by calcium chloride. The influence of membrane module of submerged and external type on membrane fouling was investigated. The effect of soap and protein on the membrane fouling in the external type membrane module was also studied. The removal of soap resulted in decreasing the membrane fouling. It was shown that the protein and the membrane were affected by the soap.

• Resources Recycling
• /
• v.16 no.6
• /
• pp.20-27
• /
• 2007

This paper presents a detailed experimental study on the durability properties of mortar matrix made with two kind of recycled fine aggregates(RAA, RAB) and five replacement levels (0, 25, 40, 75 and 100) of the recycled fine aggregates as a partial replacement of natural fine aggregate (NA). The durability properties of mortar matrix was evaluated using compressive strength, chloride ion ingress, sulfate attack and carbonation. The test results indicated that the water absorption and Adhered mortar of the recycled fine aggregate was a major factor controlling durability properties. Hereafter, when using built recycled fine aggregate is expected, appropriate removal Adhered mortar and reasonable replacement ratio of recycled fine aggregates was 25% weight of cement are advised to apply to the concrete materials.

• Polymer(Korea)
• /
• v.37 no.4
• /
• pp.533-538
• /
• 2013

Sodium chloride is present in our body fluids, and the blood contains approximately 0.9 wt% salt, which plays an important role in maintaining the osmotic pressure. However, the amount of salt intake has consistently increased, and an excessive intake can be the cause of high blood pressure, etc. In this study, it was investigated in vivo and in vitro whether biocompatible ionic polymers with K or Ca ions can be replaced by Na ions through an ion exchange process to be excreted. Among the polymers, Ca-polystyrene sulfonate, K-polystyrene sulfonate, Ca-carrageenan, and Ca-tamarind had an excellent Na exchange ability in the body temperature, simulated gastric fluid and also simulated intestinal fluid. The mechanism of Na removal by absorption and excretion without changing food taste in the mouth through the insolubility properties of these polymers is expected to be a solution for the current problems related with excess sodium intake.