• Journal of Soil and Groundwater Environment
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• v.22 no.2
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• pp.1-9
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• 2017

Passive treatment systems are commonly used for remediation of mine drainage waters because they do not require continuous chemical inputs and operation. In this study, the selection and design criteria for such systems were evaluated, particularly the two most commonly used ones, i.e., permeable reactive barriers (PRBs) and vertical flow biological reactors (VFBRs). PRBs and VFBRs are operated on the same principles in terms of biochemical reaction mechanisms, whereas differences relate to configuration, engineering, and water management. In this study, each of these systems were described with respect to key design variables, such as metal removal mechanisms and removal rates, effectiveness and longevity, general design and construction, flow capacity, and cost. The information provided from this study could be used as a design guideline when a passive treatment option is considered for potential remediation of a mine site.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.8
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• pp.651-657
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• 2003

A new mechanical-electrical hybrid passive damping treatment is proposed to improve the performance of structural vibration control. The proposed hybrid passive damping system consists of a constrained layer damping treatment and a shunt circuit. In a passive mechanical constrained layer damping, a viscoelastic material damping layer is used to control the structural vibration modes in high frequency range. The passive electrical damping is designed for targeting the nitration amplitude in the low frequency range. The governing equations of motion are derived through the Hamilton's principle. The obtained mathematical model Is validated experimentally. The presented theoretical and experimental techniques provide invaluable tools for controlling the multiple modes of a vibrating structure over a wide frequency band.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.362-367
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• 2003

A new mechanical-electrical hybrid passive dam ping treatment is proposed to improve the performance of structural vibration control. The proposed hybrid passive damping system consists of a constrained layer damping treatment and a shunt circuit. In a passive mechanical constrained layer damping, a viscoelastic material damping layer is used to control the structural vibration modes in high frequency range. The passive electrical damping is designed for targeting the vibration amplitude in the low frequency range. The governing equations of motion are derived through the Hamilton's principle. The obtained mathematical model is validated experimentally. The presented theoretical and experimental techniques provide invaluable tools for controlling the multiple modes of a vibrating structure over a wide frequency band.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.107-111
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• 2004

This study was undertaken to summarize of the efficiencies of the passive treatment system and suggest future studies for the solution of mine drainage problem. Flow rates of mine drainage from the abandoned coal mines are about 80,000 ton/day. Contaminated mine drainages over about 50 ton/day of flow rate were treated by passive treatment facilities such as Successive Alkalinity Producing Systems(SAPS), oxidation pond and oxic wetland. Chemical analysis for 13 passive coal mine treatment facilities showed that SAPS was the core of treatment facilities because the variation of Fe removal rates was relatively smaller than any other processes and re-leaching of Fe was not measured. The performance and life of SAPS depended on decrease in permeability and retention time due to accumulation of sludge. It is inferred that upgrade of design of the passive treatment system and in-situ treatment using underground void will be necessary for the amelioration of the mine drainage with high metal loading rates.

• Journal of Plant Biology
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• v.31 no.2
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• pp.113-119
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• 1988

The effects of the defoliant and desiccant dimethipin(2,3-dihydro-5,6-dimethyl-1,4-dithiin-1,1,4,4-tetraoxide) on the passive permeability and osmotic ground value of onion(Allium cepa L.) epidermal cells were investigated by plasmometric method. The osmotic ground value and the water permeability of onion epidermal cells were decreased by 9.8% and 41.2%, respectively, and the passive permeabilities of nonelectrolytesurea, methylurea, ethylurea and malonamide-were also decreased by the range of 15.7%∼57.8% after treatment with 10-3M dimethipin. After treatment with 10-4M dimethipin, the osimotic ground value and the solute permeability of onion epidermal cells were also decreased by 3.7% and 24.5%∼48.8%, respectively, but the water permeability of onion epidermal cells was increased by 8.3%. It was suggested that dimethipin treatment modified the cell membrane of onion epidermis.

• Journal of Periodontal and Implant Science
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• v.39 no.2
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• pp.199-204
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• 2009

Purpose: Excessive gingival display and short clinical crowns due to altered passive eruptions are major concerns for a considerable number of patients visiting dental clinics. Altered passive eruptions could be corrected through various types of periodontal surgery conformable to a classification. 3 cases are reported here on the esthetic correction of altered passive eruption to evaluate results of crown lengthening procedure. Methods: Three patients whose major complaints were excessive gingival display and short teeth were picked out for this case study. Before treatment, clinical and radiological exam was performed to choose type of surgery. Thickness and width of keratinized gingiva was measured in all three patients then they were treated by surgical methods including flap operation and depigmentation under subsequent diagnosis. Results: Uneventful healing and stable gingival margin were observed in all three patients except recurrence of gingival pigmentation of one patient. Conclusions: The treatment of altered passive eruption requires precise diagnostic procedure and could achieve better esthetic outcomes when it is accompanied by other orthodontic and orthognathic treatment.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.352-355
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• 2003

27 passive systems in 21 mines constructed by The Coal Industry Promotion Board since 1996 were investigated to evaluate the treatment efficiency of systems and find problems in each system, which will eventually lead to the improvement or suggesting the alternative method of the passive treatment system. Problems in operation include overflow, leakage, inefficiency and unusablness. The efficiency of systems which has been evaluated by metal(Fe) removal rate and/or by acidity removal rate do not reflect the poor removal rate of S $O_4$$^{2-}$. Especially high concentration of S $O_4$$^{2-}$ and high COD in the beginning of the operation would decrease the bacteria activity due to the lack of the nutrition. To solve the problem of overflow the upflow-type SAPS is being considered.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.504-510
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• 2003

This study has been carried out to evaluate the passive treatment systems for acid mine drainage in Korea and to suggest, if possible, the method for the improvement. 35 passive treatment systems in 27 mines have been constructed since 1996. SAPS, being the main process, was combined with more than one of processes such as anaerobic wetland, aerobic wetland, and oxidation pond for the construction of passive treatment system. Problems observed during the operation include the poor sulfate removal ratio, overflow, leakage, unusabless of the whole system, and inefficiency. The reasons of the poor sulfate removal ratio are believed that the low temperature during the winter prohibits the SRB activity and HRT for bacterial sulfate reduction is insufficient. An alternative method In Adit Sulfate Reducing System which enables to keep the temperature constant at about $15^{\circ}C$ was suggested. IASRS is the methods of placing the SAPS inside the adit, which enables the temperature around the system constant can be maintained. The experiments using the laboratory scaled model systems made up of four sections showed high efficiencies in pH control and metal removal ratios, but showed still low sulfate removal ratio of about $23\%$ also with high COD at the beginning of the operation.

• The Journal of Korean Physical Therapy
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• v.15 no.3
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• pp.126-152
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• 2003

The purpose of this study was to evaluate the value of passive caudal gliding mobilization of the glenohumeral joint on the range of motion (ROM) of active and passive abduction; to evaluate the value of pain relief through visual analogue scale (VAS); to evaluate the correlation between improvement of shoulder abduction and intra-articular movement measured by fluoroscopy in frozen shoulder patients. The subjects consisted of twenty-one patients with clinically diagnosed frozen shoulder (11 males, 10 females) between 40 and 63 years of age (mean age : 52.7 years). The traction and caudal gliding mobilization based on the convex-concave rule in the resting position and at end range of abduction was peformed for 15 minutes per day and was repeated 10 times during a 2 week period. The ROM of abduction was measured by goniometer and pain was measured by VAS. The intra-articular movement was measured by fluoroscope, Neurostar Plus TOP (Siemens, Germany). ROM measurements of each patient was acquired at pre-treatment, immediate post-treatment and 2 week post-treatment. Statistical analysis was performed using SPSS 10.0 for Windows software and data was analyzed using the paired-test and the pearson correlation. The results of this study are as follows: 1. There was a significant decrease of VAS between pre-treatment data and 2 week post-treatment data (P<.05) but no significant difference between pre-treatment and immediate post-treatment data (P>.05). 2. There was a significant increase in ROM of active and passive abduction in the pre-treatment data, immediate post-treatment data, and in 2 week post-treatment data (P<.05). 3. With regard to results of the joint play test, there was a significant difference in the grade of traction between pre-treatment data and immediate post-treatment data and between pre-treatment data and 2 week post-treatment data (P<.05). There was no significant difference between immediate post-treatment data and 2 week post-treatment data (P>.05). 4. With regard to results of the joint play test, there was a significant difference in the grade of caudal gliding between pre-treatment data and immediate post-treatment data and between pre-treatment data and 2 week post-treatment data (P<.05). There was no significant difference between immediate post-treatment data and 2 week post-treatment data (P>.05), 5. With regard to the results of fluoroscopic findings, there was a significant change of the glenohumeral joint space between pre-treatment data and immediate post-treatment data and between immediate post-treatment data and 2 week post-treatment data (P<.05). There was no significant change of the glenohumeral joint space between immediate post-treatment data and 2 week post-treatment data (P>.05). 6. With regard to the results of fluoroscopic findings, there was a significant change of acromiohumeral joint space between the three data (pre-treatment data, immediate post-treatment data, 2 week post-treatment data) (P<.05). 7. Mobility grade by joint play test was significantly increased and was correlated to improved ROM of active and passive abduction (P<.05). In this study of frozen shoulder, passive caudal gliding techniques of the glenohumeral joint results in statistically significant changes in active and passive abduction as well as in VAS. There is also a significant correlation between joint play test and ROM of abduction.

• The korean journal of orthodontics
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• v.48 no.5
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• pp.326-332
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• 2018

Objective: This study was performed to compare the perception of pain between patients treated with passive self-ligating fixed appliances and those treated with Invisalign aligners. Methods: This prospective study conducted in Saudi Arabia used an estimated sample of 64 patients from a private dental clinic. After obtaining written informed consent, the patients were divided into two groups; one group (n = 32) was treated using passive self-ligating fixed appliances and the other group (n = 32) using $Invisalign^{(R)}$ aligners. Immediately after fitting the appliances, the patients' perception of pain was evaluated through a close-ended and coded self-administrated questionnaire by using a visual analog scale (VAS). Their responses were recorded at 4 hours, 24 hours, day 3, and day 7. Mann-Whitney U-test, Kruskal-Wallis test, and Pearson's chi-square test were performed for statistical analysis. Results: A lower percentage of patients treated with Invisalign aligners reported pain than did patients treated with passive self-ligating fixed appliances, and these differences were statistically significant (p = 0.001). Similarly, the mean VAS score for the Invisalign group was significantly lower than that for the passive self-ligating fixed appliance group at different intervals during the first week of treatment. The intensity of pain with both appliances peaked at 24 hours (mean VAS score, 3.87) and was lowest (mean VAS score, 1.62) on day 7. Conclusions: During the first week of orthodontic treatment, patients treated with Invisalign aligners reported lower pain than did those treated with passive self-ligating fixed appliances.