• Journal of Environmental Science International
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• v.6 no.3
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• pp.219-224
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• 1997

The cloging phenomenon in the fixed film reactor Is shown when biomass growth Is excessive for long operating time. In addition, effluent water Quality gets worse because of detachment of biomass. In this study, we conducted air-backwashing to sustain biomass In reactor to complement these defects. The results of experimental are showed In the following conclusion. The detachment rate was 19.5 - 38.0% when the organic loading rate was 0.40 - 1.32 kg COD/$m^3$/day, the k - backwashing Intensity was 2 L/min(6.7 $m^3$/$m^2$/hrl and the backwashing time was 15 - 19 seconds. And the detachment rate was 32.2 - 58.6 % when the organic loading rate was 1.37 - 2.27 kg COD/$m^2$/day, the backwashing time was 1 - 12 minutes. As orgnic loading rate and backwashing time ale Increased, detachment of fixed biomass Is Increased. The detachment equation with detachment rate(DR, %), backwashing time(BWT, min), fixed biomass concentration(FB. mg/L), and organic leading rate(OLR, kg COD/ms/day) through multiple linear regession was given by the following equation: DR : 17.964 $BWT^{0.1407} FB^{0.0597} OLR^{0.1946}$

• Journal of Biosystems Engineering
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• v.25 no.2
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• pp.151-158
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• 2000

Detachment rate of mature fruits of the Lycium chinense Mill with various frequency, amplitude, and shaking time using an experimental vibratory system was analyzed. The experimental vibratory system was designed such that the frequency, amplitude, and shaking time could be controlled easily. The detachment rate increased as the frequency increased at constant amplitude and increased as the amplitude increased at constant frequency. The contents of the detached immature fruit, however, also increased as the frequency and amplitude increased, which was undesirable for the detachment efficiency considering the only mature 900 rpm and amplitude of 35 m for the shaking time of three seconds.

• Journal of Environmental Science International
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• v.3 no.3
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• pp.263-271
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• 1994

A detachment of biofilm was investigated in an inverse fluidized bed biofilm reactor(IFRBR). The biofilm thickness, 5 and the bioparticle density, Pm were decreased by the increase of Reynolds number, Re and the decrease of biomass concentration, h. The correlations were expressed as $\delta$=6l.6+16.33$b_c$-0.004Re and Ppd=0.3+0.027$b_c$- 2.93x$l0^{-5}$ no by multiple linear regression analysis method. Specific substrate removal rate, q was derived by F/M ratio and biofilm thickness as q=0.44.+0.82F/M-5.Ix10$-4^{$\delta$}$. Specific biofilm detachment rate, bds was influenced by FIM ratio and Reynolds number as $b_{ds}$=-0.26+0.26F/M+ 2.17$\times$$10^{-4}$Re. Specific biofilm deachment rate in an IFBBR was higher than that in a FBRR(fluidized bed biofilm reactor) because of the friction between air bubble and the bioparticles.

• Membrane and Water Treatment
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• v.11 no.1
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• pp.1-10
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• 2020

An understanding of particle-particle interactions in filtration requires studying the detachment as well as the attachment of nanoparticles. Nanoparticles captured in a granular media filter can be released by changing the physicochemical factors. In this study, the detachment of captured silver nanoparticles (AgNPs) in granular media filtration was examined under different ionic strengths, ion type, and the presence or absence of natural organic matter (NOM). Filtration velocity and ionic strength were chosen as the physical and chemical factors to cause the detachment. Increasing filtration velocity caused a negligible amount of AgNP detachment. On the other hand, lowering ionic strength showed different release amounts depending on the background ions, implying a population of loosely captured particles inside the filter bed. Overall detachment was affected by ionic strength and ion type, and to a lesser degree by NOM coating which resulted in slightly more detachment (in otherwise identical conditions) than in the absence of that coating, possibly by steric effects. The secondary energy minimum with Na ions was deeper and wider than with Ca ions, probably due to the lack of complexation with citrate and charge neutralization that would be caused by Ca ions. This result implies that the change in chemical force by reducing ionic strength of Na ions could significantly enhance the detachment compared to that caused by a change in physical force, due to a weak electrostatic deposition between nanoparticles and filter media. A modification of the 1-D filtration model to incorporate a detachment term showed good agreement with experimental data; estimating the detachment coefficients for that model suggested that the detachment rate could be similar regardless of the amount of previously captured AgNPs.

• Clinics in Shoulder and Elbow
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• v.25 no.2
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• pp.93-100
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• 2022

Background: Subscapularis tendon insertion at the first facet has separate layers (deep and superficial). The purpose of this study is to evaluate postoperative clinical outcomes and radiological healing according to each layer of detachment in the first facet involving subscapularis tendon tear. Methods: Eighty-three patients who underwent arthroscopic repair due to First facet involving the scapularis tendon tear accompanying small to medium sized posterosuperior cuff tear were classified into three groups (group A: deep layer partial detachment, group B: deep layer complete detachment, but no superficial layer detachment, and group C: deep layer and superficial layer complete detachment). Subscapularis tendon healing was evaluated using computed tomography arthrogram and clinical result was evaluated using American Shoulder and Elbow Surgeons (ASES) shoulder score, Constant score and University of California Los Angeles (UCLA) shoulder score. Results: Retear rate of the subscapularis tendon was 2.2%, 18.2%, and 33.3% in group A, group B, and group C, respectively. These rates showed statistically significant difference among the three groups, which were classified by deep and superficial layer detachment in the first facet (p=0.003). Group A showed significant difference in subscapularis tendon healing compared with group B and group C (p=0.018 and p<0.001, respectively), but there was no statistical difference between group B and group C (p=0.292). Regarding clinical outcomes, there was no significant difference among three groups in ASES and UCLA score at final follow-up (p=0.070 and p=0.106, respectively). Conclusions: Complete detachment of deep layer may be related with retear occurrence regardless with detachment of superficial layer, but clinical outcome may not be related with each layer detachment in the first facet involving subscapularis tendon tear.

• Advances in environmental research
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• v.6 no.1
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• pp.35-51
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• 2017

The use of Granular Activated Carbon (GAC) and naturally occurring silica (Sand) as filtration media in water and waste water treatment systems is very common. While GAC offers the additional functionality of being an "adsorptive" filter for dissolved organics it is also more expensive. In this paper we present an experimental evaluation of the performance of a bed of GAC for colloid removal and compare the same with that from an equivalent bed of Sand. The experiments are performed in an "intermittent" manner over extended time, to "simulate" performance over the life of the filter bed. The experiments were continued till a significant drop in water flow rate through the bed was observed. A novel "deposition" and "detachment" rate based transient mathematical model is developed. It is observed that the data from the experiments can be explained by the above model, for different aqueous phase electrolyte concentrations. The model "parameters", namely the "deposition" and "detachment" rates are evaluated for the 2 filter media studied. The model suggests that the significantly better performance of GAC in colloid filtration is probably due to significantly lower detachment of colloids from the same. While the "deposition" rates are higher for GAC, the "detachment" rates are significantly lower, which makes GAC more effective than sand for colloid removal by over an order of magnitude.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.673-679
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• 2004

Particle breakthrough can occur by either the breakoff of previously captured particles (or flocs) or the direct passage of some influent particles through the filter. Filtration experiments were performed in a laboratory-scale filter using spherical glass beads with a diameter of 0.55 mm as collectors. A single type of particle suspension (Min-U-Sil 5, nearly pure $SiO_2$) and three different destabilization methods (pH control, alum and polymer destabilization) were utilized. The operating conditions were similar to those of standard media filtration practice: a filtration velocity of 5 m/h. To assess the possibility of particle detachment during the normal filtration, a hydraulic shock load (20% increase of flow rate) was applied after 4 hours of normal filtration. The magnitude of particle detachment was proportional to the particle size for non-Brownian particles. At the same time, less favorable particles, i.e., particles with larger surface charge, were easily detached during the hydraulic shock load. Therefore, proper particle destabilization before filtration is crucial for maximum particle removal as well as minimum particle breakthrough.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3919-3924
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• 2009

To evaluate clinical results of silicone oil injection for retinal detachment. The 45 eyes of 44 patients underwent vitrectomy and silicone oil injection from 1999 to 2002. 1.There were no history of previous retinal surgery and ocular trauma. In 24 of the 45 eyes(53%) visual acuity increased and stabilized in 18 of the 45 eyes(40%). 2. 1 of 16 eyes(6.3%) had recurred retinal detachment after silicone oil removal. 3. Final retinal reattachment was achieved in 44 eyes(97%). Postoperative complications were cataract(16 eyes), glaucoma(10 eyes), emulsification of silicone oil(5 eyes), keratopathy(2 eyes) and recurrent retinal detachment(1 eye). These results show that silicone oil injection for primary retinal detachment yields a high rate of anatomic success and the good visual outcome

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.02a
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• pp.300-308
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• 2000

• Clinics in Shoulder and Elbow
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• v.25 no.2
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• pp.101-105
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• 2022

Background: Rotator cuff tears cause pathologies of the long head of the biceps tendon (LHBT). One of the surgical treatments for such a tear is LHBT tenodesis to the humerus. This study aims to compare simultaneous rotator cuff repair and LHBT tenodesis with or without detachment of the proximal end of the LHBT (PELHBT) from its site of adhesion to the glenoid. Methods: This retrospective study involved patients affected by LHBT pathology with rotator cuff tear. The patients were divided into two groups, with or without PELHBT detachment from the glenoid. Therapeutic outcomes were investigated by evaluation of patient satisfaction, pain based on visual analog scale, shoulder function based on Constant score and simple shoulder test, and biceps muscle strength based on the manual muscle testing grading system before surgery, at 6 months, and at the final visit after surgery. Results: Groups 1 and 2 comprised 23 and 26 patients, respectively, who showed no significant differences in demographic characteristics (p>0.05). Shoulder function, biceps muscle strength, pain, and satisfaction rate improved over time (p<0.05) but were not significantly different between the two groups (p>0.05). No post-surgical complication was found in either group. Conclusions: There was no difference in final outcomes of tenodesis with or without detachment of the PELHBT from the supraglenoid tubercle. Such tendon detachment is not necessary.