• Advances in nano research
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• v.13 no.6
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• pp.513-525
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• 2022

In this study, it was aimed to evaluate direct oxidation of aqueous solution containing cefalexin antibiotic with new generation Sn/Sb/Ni: 500/8/1 anode. The fact that there is no such a study on treatment of cefalexin with these new anode made this study unique. According to the operating parameters evaluation COD graphs showed clearer results compared to TOC and CLX and thus, it was it was chosen as major parameter. Furthermore, pseudo-first degree kd values were calculated from CLX results to show more accurate and specific results. Experimental results showed that after 60 min of electrochemical oxidation, complete removal of COD and TOC was accomplished with 750 mg L^-1 KCl, at pH 7, 50 mA cm^-2 current density and 1 cm anode-cathode distance. Also, the stability of the Sn/Sb/Ni anode was evaluated by taking SEM and AFM images and XRD analysis before and after of electrochemical oxidation processes. According to the results, it was not occurred too much change on the anode surface even after 300 h of electrolysis. Thus, it was thought that the anode material was not corroded to a large extent. Furthermore, the removal efficiencies were very high for almost all the time and conditions. According to the results of the study, electrochemical oxidation with new generation Sn/Sb/Ni anodes for the removal of cefalexin antibiotic was found very successful and applicable due to require less reaction time complete mineralization and doesn't require pH adjustment step compared to other studies in literature. In future studies, different antibiotic types should be studied with this anode and maybe with real wastewaters to test applicability of the process in treatment of pharmaceutical wastewaters containing antibiotics, in a better way.

• Journal of Korean Society on Water Environment
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• v.24 no.1
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• pp.78-85
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• 2008

Evaporation of selected toxic volatile chlorinated hydrocarbons was studied in laboratory soil columns. The evaporation values were obtained for the ten volatile chlorinated hydrocarbons at two different temperatures ($12^{\circ}C$ and $21^{\circ}C$) from columns filled with silty clay loam and sandy loam soils. 1,1,1-Trichloroethane, trichloroethylene and chloroform evaporated considerably (36.7~54.6% removal), carbon tetrachloride, 1,2-dichlorobenzene, tetrachloroethylene, 1,3-dichlorobenzene, dichlorobromethane and dibromochloromethane to a lesser extent (15.3~39.3% removal), and bromoform evaporated poorly (<10 percent removal) at both temperature. Volatile chlorinated hydrocarbons concentration did not affect evaporation, no statistically significant difference in evaporation between the soil types was found. However, temperature affected evaporation, the effect of concentration on the evaporation was not conclusive.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.80-86
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• 2013

In this study, the photocatalytic reactor system equipped with photocatalyst-carrying-silica-media cartridges [photocatalytic reactor system (1)] was used to perform the treatment of waste air containing malodor and volatile organic compound (VOC). The result of its performance was evaluated and compared with that of the photocatalytic reactor system equipped with commercial photocatalyst-carrying-nonwoven filter-media cartridges [photocatalytic reactor system (2)]. In case of photocatalytic reactor system (1), at the 1st stage of run the removal efficiencies of ethanol and toluene continued to be 80% and 20%, respectively. However, unlike toluene, the removal efficiency of ethanol dropped to 40% at the end of the 1st stage of run. The removal efficiency of hydrogen sulfide decreased from 100% to 90%. At the 2nd stage of its run the removal efficiency of ethanol decreased to 10% while the removal efficiencies of hydrogen sulfide and toluene remained as same as 90% and 20%, respectively, even though the inlet load of toluene increased by factor of four. In the 3rd stage of its run, as the result of application of aluminium-coated reflector film to the inner wall of photocatalytic reactor system, the removal efficiencies of ethanol and toluene increased by 5% to be 15% and 25%, respectively. In case of photocatalytic reactor system (2), at the 1st stage of its run, the removal efficiencies of ethanol, hydrogen sulfide and toluene continued to be 10%, 97% and 100%, respectively. However, at 2nd stage of its run their removal efficiencies became 5%, 95% and 2~3%, respectively, which showed that the removal efficiencies of ethanol and hydrogen sulfide decreased insignificantly while the removal efficiency of toluene dropped significantly from the perfect elimination. Moreover, the reflector film did not affect the performance of photocatalytic reactor system (2) at all. Therefore the removal of ethanol, hydrogen sulfide and toluene by photocatalytic reactor system (2) was mainly attributed to hydrophobic adsorption of its nonwoven filter media and its extent of photocatalytic removal turned out to be negligible, compared to that of photocatalytic reactor system (1).

• Journal of Korean Neurosurgical Society
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• v.30 no.4
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• pp.472-478
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• 2001

Objectives : The authors present a retrospective analysis of 100 consecutive adult patients harboring craniopharyngiomas who underwent microsurgical resection between 1981 and 1999 to assess the long-term outcome of surgical treatment and to determine the most optimal management strategy. Methods : The extent of surgical removal was divided into four categories ; GTR(gross total removal), RSTR(radical subtotal removal), STR(subtotal removal),and PR(partial removal). The median follow-up period was 50 months(4-198). CT scan and/or MR imaging and hormonal status were evaluated to the last follow-up. Results : Visual disturbance was the most common presentation, which was improved in 42 cases and aggravated in 19 cases following the operation. Hypopituitarism was detected in 56 patients preoperatively, 82 during the immediate postoperative period, and 76 at the last follow-up. Improvement of pituitary function was not observed in any of these patients. Twenty of 100 patients showed recurrence at the mean of 27 months(3 to 196). The median progression-free survival(PFS) time of all patients was 145 months and 5-year PFS rate was 74%. Five-year PFS rate of GTR or RSTR group(71%) was significantly higher than that of STR or PR group(30%)(p=0.01). Postoperative radiation therapy significantly prolonged the PFS from 94 months in non-radiation group to 182 months(p=0.002). However, there was no statistical difference in number of patients who required hormonal replacement therapy between radiation and non-radiation group. Conclusion : Visual disturbance can be improved by early diagnosis and surgical decompression. GTR or RSTR in selected patients is considered a proper surgical strategy. Post-operative radiation therapy for residual tumors must be considered, although the ideal timing of radiation therapy is to be determined.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.2 no.2
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• pp.39-46
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• 1982

A model of substrate removal by rotating discs has been developed for a better understanding of the process, and the performance of the system has been evaluated under steady and unsteady state. The model was constructed based upon mass transfer of the substrate from the bulk solution to the biofilm and a simultaneous removal of the substrate by the biomass. The model is composed of a few sets of differential equations representing mass balance within the elements of a liquid film and a biofilm, and in the bulk solution. Substrate removal efficiency of the process is largely dependent on a diffusion coefficient of the substrate within the biofilm and a maximum rate of substrate removal of the biomass. The efficiency is affected to a greater extent when the substrate concentration is low and the maximum substrate removal rate is high. The efficiency increases proportionally with increasing film depth when the biofilm is shallow, however, the rate of increase gradually decreases with an increase of the film depth. As the film reaches a limiting depth, the efficiency remains constant. Unlike the steady state, the effluent quality is affected by the tank volume under dynamic state. Increasing tank volume decreases peak concentration of the effluent under peak loading. Additional tank volume provides a buffer capacitya.gainst a peak loading and the holding tank behaves like an equalization tank.

• Journal of Korean Neurosurgical Society
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• v.53 no.3
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• pp.180-182
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• 2013

We describe a case of intracranial carotid artery occlusion due to penetrating craniofacial injury by high velocity foreign body that was relieved by decompressive surgery. A 46-year-old man presented with a penetrating wound to his face. A piece of an electric angular grinder disc became lodged in the anterior skull base. Computed tomography revealed that the disc had penetrated the unilateral paraclinoid and suprasellar areas without flow of the intracranial carotid artery on the lesion side. The cavernous sinus was also compromised. Removal of the anterior clinoid process reopened the carotid blood flow, and the injection of glue into the cavernous sinus restored complete hemostasis during extraction of the fragment from the face. Digital subtraction angiography revealed complete recanalization of the carotid artery without any evidence of dissection. Accurate diagnosis regarding the extent of the compromised structures and urgent decompressive surgery with adequate hemostasis minimized the severity of penetrating damage in our patient.

• Proceedings of the KSRS Conference
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• v.2
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• pp.736-739
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• 2006

While hyperspectral data are very rich in information, their processing poses several challenges such as computational requirements, noise removal and relevant information extraction. In this paper, the application of advanced scale-space filtering to selected hyperspectral bands was investigated. In particular, a pre-processing tool, consisting of anisotropic diffusion and morphological leveling filtering, has been developed, aiming to an edge-preserving smoothing and simplification of hyperspectral data, procedures which are of fundamental importance during feature extraction and object detection. Two scale space parameters define the extent of image smoothing (anisotropic diffusion iterations) and image simplification (scale of morphological levelings). Experimental results demonstrated the effectiveness of the developed scale space filtering for the enhancement and smoothing of hyperspectral remote sensing data and their advantage against watershed over-segmentation problems and edge detection.

• Korean Journal of Microbiology
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• v.20 no.4
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• pp.201-209
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• 1982

An enzyme, named GTP cyclohydorlase, that catalizes the hydrolytic removal of carbon No.S of GTP has been partially purified from extracts of Pseudomonas putida (IAM 1506). The enzyme exists in two molecuar weight forms : a high molecular weight form (150,000) and a low molecular weight from (40,000). The high molecular weight form has been purified 25-fold. Some of the properties of the enzyme are as follows : It functions optimally at pH8.0, and at $52^{\circ}C$. The Km value for GTP is $20{\mu}M$. Divalent cations $(Cd^{2+}\;and\;Hg^{2+})$ 2+/) at a concentration of 5mM inhibit completely the enzyme activity. No metal ion including $Mg^{2+}$ is needed for the catalysis. The enzyme is heat labile ; its half at $57^{\circ}C$ is 1.5 min. Of a number of nucleotides tested, only GDP was used to any extent as substrbte in place of GTP. One of the products of the enzyme is determined to be a dihydro-neopterin compound.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.197-203
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• 1999

Stainless steels in general has passive film having strong corrosion resistance on surface. Therefore it must be necessarily removed by etching in mixing solution of sulfuric and chloric acid before Nitriding treatment. But in the ion nitriding, nitride layer was easily formed because passive film was removed without difficult by sputtering effect. The removal extent of these passive films was greatly effected by gas mixing ratios and pressure and holding times of pre sputtering factors in pre sputtering stage. As a results of experiment it has been known that pre sputtering pressure and holding time was not nearly effective on the formation behavior of nitride layer. But when A/H2 gas mixing ratios was 1/2 (vol%) was the most effective of the all pre sputtering conditions. It was resulted from the combination of mechanical reaction byArgon bombardment and chemical reaction by reduction of hydrogen on the passive film.

• KSBB Journal
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• v.26 no.4
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• pp.300-304
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• 2011

Phytases are hydrolytic enzymes that catalyze the sequential hydrolysis of phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate) to myo-inositols with lower numbers of phosphate groups. Two types of phytases have been identified which initiate hydrolysis of the phytic acid at either the 3- or 6- position of the inositol ring. In the present investigation, a mathematical model was proposed and computed to estimate maximum enzyme reaction rate constants which fit the experimental data obtained by other authors. Although the data points were scattered to some extent, good agreement was found between the model and the experiment data. It appears that the maximum rate constants of removal of the first, second, and third phosphate groups were not equal. Also there was neither a steady trend upward or downward in the rate constants with the stepwise hydrolysis reactions.