• Journal of Environmental Health Sciences
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• 제27권3호
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• pp.99-106
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• 2001

A laboratory experiment was performed to investigate phosphorus and nitrogen removal from synthetic wastewater by intermittently activated sludge process packed with aluminium plate. Three continuous experimental systems, I. e. an intermittently activated sludge process(Run A), an intermittently activated sludge process with an aluminium plate packed into the reactor(Run B), and a reactor post stage(Run C) were compared. In the batch experiments, the phosphorus removal time in the reactor packed with copper and aluminium plate simultaneously was faster than that of the reactor packed with only an aluminium plates. However, the reactor packed with only an aluminium plate could be used for phosphorus removal. Move phosphorus was removed with an increase of surface area of aluminium plate and electrolysis(NaCl) concentration. The efficiency of COD and nitrogen removal was not affected in Run B. However, the phosphrus removal efficiency decreased because of reaction products and activated sludge which gradually covered gradually the surface of the aluminium plate. The efficiency of phosphorus removal in Run C was 86.3% at the HRT of 3.2 hours. Especially, the efficiency of phosphorus removal in Run C was higher than that in Run B.

• Oral Biology Research
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• 제42권4호
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• pp.222-227
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• 2018

The purpose of this study was to determine the cause and risk factors of removing bone plateby investigating and analyzing 359 patients who underwent reduction of fracture or orthognathic surgery with bone plate insertion over the past 3 years. Patients were evaluated with respect to age, smoking status, reason for insertion of plates, the numbers of inserted plates, sites of insertion, time between insertion and removal, reasons for removal of plates. The removal rate of bone plates was 33.1%. Of these, 17.0% of patients had clinical symptoms which led to remove plates. The removal rate of men was 29.9% and the rate of women was 39.2%. There were high removal rates from less than 20s (45.8%) and 20s (34.4%) those who are relatively young age group. On the other hand people in their 50s had a removal rate of 27.8% which was higher than those in their 60s with a rate of 20.7%. The removal rate of bone plate inserted into the mandible was 33.5%, and the removal rate of bone plate inserted into the maxilla was 34.7%. The mean period between the insertion and removal of bone plate was 10.9 months. The main reason for the removal of bone plate was the patient's requirement (44.5%). The most common cause of clinical symptoms was infection (22.7%). Infection was manifested within about a year and led to the plate being removed. Therefore, lowering the possibility of infection after surgery could decrease the removal rate of bone plate.

• Journal of Environmental Science International
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• 제8권6호
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• pp.705-710
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• 1999

The fundamental experiments on the phosphorus removal from water were carried out by the batch and continuous reactors which used aluminium and copper plate. In this systems, the phosphorus was removed by aluminium ion generated with the electrochemical interaction (pitting corrosion) of aluminium and copper. In the batch experiments, the efficiencies of phosphorus removal increased when the surfaces of aluminium and copper plate were brushed. The phosphorus removal by aluminium ion was affected the copper plate and NaCI in this system. The optimal pH values were 5 and 6 for the phosphorus removal. The efficiency of phosphorus removal increased with increasing NaCI concentration, surface area of aluminium and copper plate. The $CUSO_4{\cdot}5H_2O$ instead of copper plate could be used as Cu source. The effluent $PO_4-P$ concentration as low as 2 $mg/{\ell}$ could have been obtained during the continuous experiment at HRT of 48 hrs.

• Environmental Engineering Research
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• 제24권2호
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• pp.318-323
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• 2019

Paper focuses on comparison between two different orifice plate configurations (plate number 1 and plate number 2) used as cavitating device in the hydrodynamic cavitation reactor for improving pollutant removal efficiencies. Effect of four different parameters such as hydraulic characteristics (in terms of range of flow rates, orifice velocities, cavitation number at different inlet pressures); cavitation number (in range of 5.76-0.35 for plate number 1 and 1.20-0.35 for plate number 2); inlet pressure (2-8 bars) and reaction time (0 to 60 min) in terms of chemical oxygen demand (COD) removal and chlorpyrifos degradation has been studied and compared. Optimum inlet pressure of 5 bars exists for degradation of pollutants for both the plates. It is found that geometry of orifice plate plays important role in removal efficiencies of pollutant. Results obtained confirmed that orifice plate 1 with configuration of 1.5 mm 17 holes; cavitational number of 1.54 performed better with around 60% COD and 98% chlorpyrifos removal as compared to orifice plate 2 having configuration of 2 mm single hole; cavitational number of 0.53 with 40% COD and 96% chlorpyrifos in 2 h duration time.

• Archives of Plastic Surgery
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• 제34권2호
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• pp.186-190
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• 2007

Purpose: Plate systems have been used for osteosynthesis of cranial and oromaxillofacial fracture. However, there is no consensus on the need for routine removal of plate and the question about indications of removal. Therefore, we present the retrospective study to clarify the indications and consensus of removal. Methods: The medical records of patients who were treated with rigid internal fixation using plates after craniofacial trauma were reviewed. Study variables included age, gender, type of fracture, type of plate, seniority of the operator, causes of removal, and time between insertion and removal. All results amendable to statistics were analyzed using SPSS 10.0 to determine which set of variables might affect the fate of the plates. Results: For a period of 10 years (March 1, 1994 through July 31, 2004), total of 41 plates(6.7%) were removed among 609 plates inserted into 419 patients; 27 plates were removed from 15 patients for infection, which is the most common cause of removal accounting for 65.8%. Mean time between insertion and removal is 35.2 months and mean age is 41.4 years. Most plates were removed from combined fracture(14.92%) and facial fracture(8.47%) and these were statistically significant. The age, gender, seniority of the operator and other variables were not statistically associated with plate removal. Conclusion: This retrospective study shows that routine removal does not appear to be clinically indicated due to respectively low removal rate and that the commonest indications for removal were infection.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제42권
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• pp.6.1-6.6
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• 2020

Background: Various types of miniplates have been developed and used for the reduction of facial bone fractures. We introduced Yang's Keyhole (YK) plate, and reported on its short-term stability. The purpose of this study was to evaluate the long-term stability of the YK plate, as a follow-up study, by examining the patients who had used the YK plate among the patients with the reduction of mandible fractures and who visited for plate removal. Methods: We reviewed the medical records of 16 patients who underwent mandibular fracture fixation using a YK plate (group I) and 17 patients who underwent mandibular fracture fixation using a conventional plate (group II). Assessment was then made on malunion, occlusal stability, discomfort during the application, and clinical symptoms. Results: From January 2015 to December 2017, a total of 36 patients underwent mandibular fracture surgery using a YK plate. A total of 16 patients received plate removal. Among them, 15 were male and 1 female. The average age was 26 years. The applied surgical sites were the 12 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of YK plate was an average of 335 days. During the same period, 45 people underwent surgery on the conventional plate. A total of 17 patients received plate removal. Among them, 15 were male and 2 females. The average age was 36 years. The applied surgical sites were the 8 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of the conventional plate was an average of 349 days. No malocclusion occurred at the time of removal, and occlusion was stable. No patient complained of joint disease or discomfort. Conclusion: The YK plate system, in which the screw was first inserted and the plate was applied, for clinical convenience did not cause any particular problem and no significant difference from the conventional plate.

• Journal of the Korean Arthroscopy Society
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• 제13권1호
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• pp.46-52
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• 2009

Purpose: To evaluate the usefulness of minimally invasive arthroscopy-assisted plate removal of a laterally inserted periarticular distal femur plate used for the treatment of AO type-C distal femur fractures. Materials and Methods: From October 2002 to November 2005, we evaluated 17 patients whose plates were removed through minimally invasive arthroscopy-assisted plate-removal technique and 15 patients who got their plates removed through conventional method without using arthroscopy, 32 patients in total. All these patients included in this study initially underwent open reduction and internal fixation of the distal femoral fractures with a lateral plate, and complained of continued pain over the lateral femoral condyle after the fracture fixation. The average age was 42.6 (ranges: 20~66) and initial fracture types included 16 cases of C1, 11 cases of C2, and 5 cases of C3 following AO/ASIF classification guidelines. Measured outcomes included: associated intra-articular pathologies, time needed to return to activities of daily living, patients' overall satisfaction, complications following the removal of hardware, and pain before and 6 months after the operation. Results: The distal-most end of the plate was placed in the knee joint in all cases and damage of the lateral articular capsule was found in 23 cases. Continuous wound discharge after surgery was found in one case who underwent arthroscopy-assisted plate removal, and it was treated by irrigation and re-suture. Average time needed to return to activities of daily living was 7 days in arthroscopy assisted group and 7.6 days in conventionally removed group. Fourteen patients (82.4%) who underwent arthroscopyassisted plate-removal reported above 'fair' satisfaction and the Visual analog scale pain score decreased from 4.9 to 1.9, six months after the plate removal. Thirteen patients(86.7%) who underwent conventional plate removal reported above 'fair' satisfaction and the Visual analog scale pain score decreased from 5.2 to 2.5, six months after the operation. Conclusion: Through minimally invasive arthroscopic-assisted plate removal, intrarticular pathology of the knee joint was able to be simultaneously identified and treated at the time of hardware removal. Damage of lateral capsule of the knee joint caused by the inserted plate for the treatment of type C distal femoral fracture was very frequently found and following the plate removal, patients experienced an improvement in pain score. We therefore recommend routine lateral distal femoral plate removal if the bony union is attained in such cases as type C distal femoral fractures whose distal most end of the plates are located in the joint.

• Journal of Dental Anesthesia and Pain Medicine
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• 제18권5호
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• pp.295-300
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• 2018

Background: Removal of the plate following Le Fort I osteotomy and BSSO (bilateral sagittal split osteotomy) is a common procedure. However, patients who undergo plate removal experience intense pain and discomfort. This study investigated the half-maximal effective concentration ($Ce_{50}$) of remifentanil in the prevention of plate removal pain under sedation using dexmedetomidine. Methods: The study evaluated 18 patients, between 18 and 35 years of age, scheduled for elective surgery. Remifentanil infusion was initiated after sedation using dexmedetomidine, and started at a dose of 1.5 ng/mL on the first patient via target-controlled infusion (TCI). Patients received a loading dose of $1.0{\mu}g/kg$ dexmedetomidine over 10 min, followed by a maintenance dose of $0.7{\mu}g/kg/h$. When the surgeon removed the plate, the patient Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score was observed. Results: The Ce of remifentanil ranged from 0.9 to 2.1 ng/mL for the patients evaluated. The estimated effect-site concentrations of remifentanil associated with a 50% and 95% probability of reaching MOAA/S score of 3 were 1.28 and 2.51 ng/mL, respectively. Conclusion: Plate removal of maxilla can be successfully performed without any pain or adverse effects by using the optimal remifentanil effect-site concentration ($Ce_{50}$, 1.28 ng/mL; $Ce_{95}$, 2.51 ng/mL) combined with sedation using dexmedetomidine.

• Journal of Korean Society for Atmospheric Environment
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• 제29권6호
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• pp.830-837
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• 2013

The purposes of this research are to know the dust removal efficiency according to the changes of gab between positive and negative plates in dust removal chamber. The experiments for dust removal efficiencies were conducted with changing the electrode-plate gab from 2 cm to 1 cm while the electric pressure, influent flow, and linear velocity were kept 5 kV, 80 L/min, and 6 cm/sec, respectively. From the experimental results of the electrode-plate gab of 2 cm, dust removal efficiencies were decreased to as low as about 50%. Attached dust on the surface of electrodes was released due to a reverse electric charge of dust. From the experimental results of the electrode-plate gab of 1 cm, dust removal efficiencies were increased to as high as about 80% due to the dust attachment velocity to the electrodes to be far more fast than influent linear velocity. Finally, to protect a attached dust from occurring a reverse electric charge it is needed to install the non-conductor between positive and negative electrodes and also to remove air humidity.

• Korean Journal of Ecology and Environment
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• 제41권spc호
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• pp.93-98
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• 2008

We investigated the effect on the removal of BOD, SS, TN and TP and algal growth inhibition of Vegetated Artificial Floating Island (VAFI), by examining microorganism activity and nutrient uptake in the batch test of various conditions: (1) Blank (Control group), (2) VAFI of $0.25m^2$, (3) AFI of $0.25m^2$ which has no vegetation, (4) buoyant plate of $0.25m^2$, (5) buoyant plate of $0.25m^2$ with linear media. The proportion of BOD removal in the VAFI, AFI, buoyant plate and buoyant plate with media were 82.7, 80.8, 45.2% and 59.6% respectively. TN removal in the VAFI, AFI and buoyant plate with media were 51.2, 31.7% and 25.1% respectively. TP removal in the VAFI, AFI, buoyant plate and buoyant plate with media were 23.3, 16.7, 10.0% and 13.3% respectively. Chlorophyll-${\alpha}$ removal in the VAFI was 97.9%. The factors of chlorophyll-${\alpha}$ removal in the VAFI accounted for the shading effect of 35.1%, microorganisms activity of 61%, and plant root of 1.8%.