• Journal of Korean Society of Transportation
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• v.8 no.2
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• pp.119-131
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• 1990

Physico-chemical properties of asphalt, aggregate, and asphalt-aggregate mixture that might influence stripping were summarized in Table 1, based on the fundamental theories concerning stripping. It was found that although physical properties of aggregate affected stripping, there was no strong correlation between the physical properties of aggregate, such as pore volume and surface area, and the stripping propensity of the aggregate. Chemical and electrochemical properties of aggregate surface in the presence of water were most important factors for stripping. All mineral aggregates tested in this study imparted distinctive pH values to the contacting water and possessed distinctive electrochemical properties as measured by zeta potential. It was found that aggregates which had relatively higher surface potential in water and/or which imparted relatively higher pH to the contacting water were more susceptible to stripping. The functionalities contained in antistripping additives tested were primary and secondary amines and those of organic nitrogen compounds. The functionalities were determined by examining their infrared spectra. Based on the interfacial energy concept, the contact angle of an asphalt drop on an aggregate surface immersed in water related to the stripping propensity. The contact angle and stripping propensity were markedly reduced by the presence of an antistripping additive. In general, all the additives tested improved stripping resistance to some extent, depending on their concentration in the asphalts. The optimum dosage of an additive varied with different asphalts, as well as different aggregates. All antistripping additives tested in this study lost their effectiveness and failed to function to some extent when maintained for hours in a hot asphalt.

• Cross-Cultural Studies
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• v.52
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• pp.393-416
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• 2018

Negative Stripping Construction in English involves the disjunction but, the adverb not, and a constituent NP. This construction is an incomplete sentence although it delivers a complete sentential meaning. Interpretation of this construction may be ambiguous in that the constituent NP can either be construed as the subject, or as the complements including the object. To generate such sentences and resolve the issue of ambiguity, we propose a construction-based analysis under direct interpretation approach, rejecting previous analyses based on deletion approaches. In so doing, we suggest a negative stripping construction rule that can account for ambiguous meaning. This rule further can enable us to explain syntactic structures and readings of Negative Stripping Construction.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.9
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• pp.935-939
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• 2006

The biological nutrient removal from domestic wastewater with low C/N ratio is difficult. Therefore, this study was performed to examine effect of operational parameters such as air supply, hydraulic retention time, pH on the nitrogen removal by ammonia stripping and to increase influent C/N ratio without required carbon source. The ammonia stripping system used for the bench-scale experiment in laboratory had a dimension of 15 cm diameter and 150 cm height. The ammonia stripping reactors were classified into two types, type AS I and type AS II, according to there using or not media. Results of the research showed that the T-N removal efficiency of AS I using plastic media is slightly higher than AS II without media. In experimental condition of air supply 30 L/min and pH 12.5, T-N removal efficiencies increased as HRT of ammonia stripping reactor became longer from 8 hr to 36 hr. In experimental condition of HRT 36 hr, it was also found that the T-N removal efficiencies improved through increase of air supply. On the other hand, C/N ratio of wastewater was increased from average 3.9 to 5.4 by ammonia stripping.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.4
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• pp.531-536
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• 2014

There are trapping and stripping methods as the technique to remove the dither motion from RLG(Ring Laser Gyro) output. V/F converter output of angular sensor to measure the dither motion is used in stripping method. But bias and scale factor error is always included in V/F converter output and is a critical limiting factor for the wide application of stripping method to RLG. Therefore there have been many researches to solve this problem. The method to accurately estimate the bias and scale factor error of V/F converter using measurements of the angular sensor acquired at data sampling rate of INS is presented in this paper. To this end, stripping technique based on model of dither motion is newly applied.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.1
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• pp.55-64
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• 1999

Large size shipyards have peformed the generating of piece and the nesting using shipbuilding-oriented CAD program, which requires higher skilled operators and lots of costs. So, medium and small size shipyards have pursued different types of piece generation and nesting (arrangement method). This research is to develop a program for the generating of pieces with parametric macro method and a STRIP program for the nesting of pieces by PC, which can be applied in such shipyards.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.5
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• pp.561-572
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• 2010

The efficiency of biological hydrolysis at $80^{\circ}C$ on municipal solid waste mixed with anaerobic digestion sludge was investigated in 100L batch reactors. The hydrolysis effect was observed within a day, when the hydrolysis reactor used for a pre-treatment reactor for methanogenesis, and the effect was observed during two days, When the reactor used for post-treatment reactor. For both configurations, methane production rate decreased, when hydrolysis was carried out more than a day. Gaseous ammonia in the hydrolysis reactors was successtully removed by the ammonia stripping system. Microbial diversity analysis on the hydrolysis reactors indicated dependency of microbial diversity on the configuration of the hydrolysis reactors. Carbohydrate and lactate degrading microbes dominated in the hydrolysis reactor, when the hydrolysis reactor used for a pre-treatment reactor for methanogenesis, while protein degrading microbes dominated in the post-treatment reactor.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.12
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• pp.893-899
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• 2011

The occurrence of THMs, the characteristics of THMs formation and removal of THMs were investigated. The treatment train of M plant consists of prechlorination, flocculation, sedimentation, filtration, ozonation, activated carbon and postchlorination. The study of THM formation indicated that about 92% of the THMs were formed in the flocculation/sedimentation/filtration process which affected by prechlorination. The formation of THMs was highly correlated to $KMnO_4$ consumption and water temperature in raw water. The regression model had showed 0.72~0.80 of determination coefficient so it could be used to predict the amount of THMs formation in finished water. Compared to the prechlorination process, the THMs formation was reduced in interchlorination process. With the addition of PAC, fewer THMs were formed in PAC-chlorination process than in chlorination-PAC process. Our results showed that air stripping could be used to remove the existing THMs.

• Applied Chemistry for Engineering
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• v.23 no.6
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• pp.561-566
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• 2012

PtRuW/C catalysts were prepared with the different molar ratios of Pt : Ru : W and their compositions were analyzed by energy dispersive X-ray (EDX). The uniform distribution of particles was observed using transmission electron microscopy (TEM). An average crystalline size of 3.5~5.5 nm was calculated based on x-ray diffraction (XRD) data. The electrochemical properties such as electrochemically active surface areas, current densities, specific activities and poisoning rates, were analyzed via CO stripping, linear sweep voltammetry and chronoamperometry. From the analysis, we observed that ternary alloy catalysts, except $PtRu_2W_2/C$, have higher current densities, specific activities and stabilities than those of commercial binary catalysts. Among all in-house catalysts, Pt5Ru4W/C showed the highest specific activity of $121.05mA{\cdot}m^{-2}$ and the lowest poisoning rate of $0.01%{\cdot}s^{-1}$.

• Journal of Chest Surgery
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• v.36 no.6
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• pp.391-396
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• 2003

Background: Recently transilluminated powered phlebectomy was introduced and used as a method of surgical treatment for varicose vein in lower extremities. The advantage of transilluminated powered phlebectomy are minimal scar and good cosmetic effect. However, the disadvantages of transilluminated powered phlebectomy is that a high priced Trivex system must be used which increases the patient's expenses. Therefore, we performed a transilluminated powered phlebectomy using an existing arthroscopic equipment instead of Trivex system and observed the effect of treatment and efficiency of the treatment. Material and Method: From March, 2000 to February, 2003, 78 patients (113 limbs) underwent transilluminated powered phlebectomy with an arthroscopic equipment. Patient's disease history, the number of operative scars and complications were reviewed. Result: The operation was performed in 133 limbs of the 78 patients (34 men, 44 women) and the age of patients were ranged from 16 to 72 years with mean age of 41.8 years. Operative time ranged from 20 to 65 minutes (average 48.7 minutes) per limb. The number of operative scar per limb from 2 to 7 (average 4.9). Postoperative complications are transient ecchymosis (78 cases) that desappeared spontaneously, edema persisting longer than 3 weeks (6 cases), remnant varicose vein (4 cases), skin perforation during operative procedure (2 cases), and contact dermatitis due to compression stocking (4 cases) The mean hospitalization day was 3.09 days. Subjective mean satisfaction degree of operation by the patients using a visual analogue scale was 92.6%. Conclusion: Our findings demonstrated that transilluminated powered phleectomy using arthroscopic equipment was possible and had good cosmetic results with acceptable complications.

• Resources Recycling
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• v.32 no.1
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• pp.21-32
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• 2023

Because the application of lithium has gradually increased for the production of lithium ion batteries (LIBs), more research studies about recycling using solvent extraction (SX) should focus on Li⁺ recovery from the waste solution obtained after the removal of the valuable metals nickel, cobalt and manganese (NCM). The raffinate obtained after the removal of NCM metal contains lithium ions and other impurities such as Na ions. In this study, we optimized a selective SX system using di-(2-ethylhexyl) phosphoric acid (D2EHPA) as the extractant and tri-n-butyl phosphate (TBP) as a modifier in kerosene for the recovery of lithium from a waste solution containing lithium and a high concentration of sodium (Li⁺ = 0.5 ~ 1 wt%, Na⁺ = 3 ~6.5 wt%). The extraction of lithium was tested in different solvent compositions and the most effective extraction occurred in the solution composed of 20% D2EHPA + 20% TBP + and 60% kerosene. In this SX system with added NaOH for saponification, more than 95% lithium was selectively extracted in four extraction steps using an organic to aqueous ratio of 5:1 and an equilibrium pH of 4 ~ 4.5. Additionally, most of the Na⁺ (92% by weight) remained in the raffinate. The extracted lithium is stripped using 8 wt% HCl to yield pure lithium chloride with negligible Na content. The lithium chloride is subsequently treated with high purity ammonium bicarbonate to afford lithium carbonate powder. Finally the lithium carbonate is washed with an adequate amount of water to remove trace amounts of sodium resulting in highly pure lithium carbonate powder (purity > 99.2%).