• 제목/요약/키워드: Removal and recovery

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수열탄화를 이용한 하수 슬러지의 고형연료화 및 에너지 회수 효율 (Hydrothermal carbonization of sewage sludge for solid recovered fuel and energy recovery)

  • 김대기;이관용;박기영
    • 상하수도학회지
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    • 제29권1호
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    • pp.57-63
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    • 2015
  • Recently, Korea's municipal wastewater treatment plants generated amount of wastewater sludge per day. However, ocean dumping of sewage sludge has been prohibited since 2012 by the London dumping convention and protocol and thus removal or treatment of wastewater sludge from field sites is an important issue on the ground site. The hydrothermal carbonization is one of attractive thermo-chemical method to upgrade sewage sludge to produce solid fuel with benefit method from the use of no chemical catalytic. Hydrothermal carbonization improved that the upgrading fuel properties and increased materials and energy recovery, which is conducted at temperatures ranging from 200 to $350^{\circ}C$ with a reaction time of 30 min. Hydrothermal carbonization increased the heating value though the increase of the carbon and fixed carbon content of solid fuel due to dehydration and decarboxylation reaction. Therefore, after the hydrothermal carbonization, the H/C and O/C ratios decreased because of the chemical conversion. Energy retention efficiency suggest that the optimum temperature of hydrothermal carbonization to produce more energy-rich solid fuel is approximately $200^{\circ}C$.

척수종양의 임상적 분석 (Clinical Analysis of Spinal Cord Tumor)

  • 최원림;신원한;조성진;김범태;최순관;변박장
    • Journal of Korean Neurosurgical Society
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    • 제30권1호
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    • pp.47-53
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    • 2001
  • Objective : This study was undertaken to evaluate operative results and prognosis according to preoperative clinical status and histopathological finding of spinal cord tumor. Methods : We analyzed of clinical feature, tumor location, histopathologic finding, operative results and prognosis in 55 patients with spinal cord tumor during last 10 years. Results : 1) The incidence of spinal cord tumors varies with the age of affected patients who are 2 to 75 years of age. Peak incidences were in the 5th & 7th decade of life, and the ratio of male to female was 1.2:1. 2) The most common histopathologic type was neurinoma(41.9%). 3) The tumors were located most frequently in the thoracic area(22 cases, 40.0%) and in the intradural extramedullary space(30 cases, 54.5%). 4) The most common initial clinical feature was pain in 20 cases(36.4%). For neurologic status on admission, 30 cases(54.5%) showed motor disturbance. 5) In radiologic studies, there were abnormal finding in 21 cases from plain X-rays among 37 cases. The entire 20 cases in when myelography was done showed subarachnoid blockade, either complete or incomplete. The magnetic resonance imaging, regard as the most accurate diagnostic method, revealed the exact location of the tumor and the relationship of the tumor with the adjacent anatomical structure. 6) The total removal was possible in 36 cases(65.5%), subtotal removal in 17 cases(30.9%) and biopsy in 2 cases (3.6%). Nineteen cases(90.5%) among 21 cases with preoperative radiculopathy group showed recovery or improvement, where as only 11 cases(36.7%) among 30 cases with preoperative motor weakness group showed recovery or improvement, with statistically significant difference(p<0.01). Pathologically, 26 cases(83.9%) among 31 cases of neurinoma and meningioma showed postoperative recovery or improved, but only 1 case(6.3%) among 16 cases of metastatic tumor, astrocytoma and ependymoma recovered. Postoperative complication noted in 5 cases(9.1%), and were noted postoperative hematoma, pneumonia, pulmonary edema and spinal cord infarction. Conclusion : Preoperative neurologic status and histopathologic finding are considered important factors of Postoperative outcome in patients with spinal cord tumor.

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Recovery of the ascending reticular activating system and consciousness following comprehensive management in a patient with traumatic brain injury: a case report

  • Jang, Sung Ho;Kwon, Young Hyeon
    • Journal of Yeungnam Medical Science
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    • 제39권4호
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    • pp.332-335
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    • 2022
  • We report on changes in the ascending reticular activating system (ARAS) concurrent with the recovery of impaired consciousness following rehabilitation and cranioplasty in a patient with traumatic brain injury (TBI), which were demonstrated on diffusion tensor tractography (DTT). A 34-year-old male patient was diagnosed with a traumatic intracerebral hemorrhage after falling from a height of approximately 7 m and underwent a right frontoparietotemporal decompressive craniectomy and hematoma removal. At 5 months after onset, when starting rehabilitation, the patient showed impaired consciousness, with a Glasgow Coma Scale (GCS) score of 4. Comprehensive rehabilitative therapy was provided until 14 months after onset, and his GCS score improved to 8. Cranioplasty was performed using auto-bone at 14 months after onset. One month after cranioplasty, his GCS score improved to 12. On the 15-month DTT, the deviated lower dorsal ARAS was restored on both sides, and the right side had become thicker. The right lower ventral ARAS was reconstructed, and increased neural connectivity of the upper ARAS was detected in both the prefrontal cortices. Thus, changes in the ARAS were demonstrated in a patient with TBI during recovery of consciousness following rehabilitation and cranioplasty.

Nano-Calcium Ameliorates Ovariectomy-Induced Bone Loss in Female Rats

  • Choi, Hyeon-Son;Han, JeungHi;Chung, Seungsik;Hong, Yang Hee;Suh, Hyung Joo
    • 한국축산식품학회지
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    • 제33권4호
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    • pp.515-521
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    • 2013
  • In this study, we examined the effects of organic types of calcium derived from oyster shell (OS-Ca) and nano-calcium (Nano-Ca) on the bio-availability and physiological responses associated with bone health in ovariectomised rats. Increased body weight, which is one of the physiological effects of ovary removal, was significantly recovered by Nano-Ca treatment (p<0.05). The reduced calcium level in the liver in ovariectomised rat was increased significantly with OS-Ca and Nano-Ca treatment (p<0.05), suggesting improved calcium bio-availability. Alkaline phosphatase (ALP), osteocalcin, and deoxypyridinoline (DPD) were analysed as biochemical markers of bone metabolism and health in the presence or absence of OSCa and Nano-Ca. ALP, osteocalcin, and DPD levels increased following ovary removal and tended to decrease after treatment with Nano-Ca, indicating that Nano-Ca induces favourable bone metabolism. This result was reflected in the recovery of bone mineral density (BMD) and bone mineral content (BMC) of the femur after Nano-Ca treatment following ovary removal. Taken together, our data show that the tested calcium treatments, especially using Nano-Ca, enhanced the bioavailability or absorption of calcium and positively affected bone metabolism in ovariectomised rats.

송전선로용 디지털 고장점 표정장치에 관한 연구 (A Study on Digital Fault Locator for Transmission Line)

  • 이경민;박철원
    • 전기학회논문지P
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    • 제64권4호
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    • pp.291-296
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    • 2015
  • Transmission line is exposed to a large area, and then faults are likely to occur than the other component of power system. When a fault occurs on a transmission line, fault locator helps fast recovery of power supply on power system. This paper deals with the design of a digital fault locator for improvement accuracy of the fault distance estimation and a fault occurrence position for transmission line. The algorithm of a fault locator uses a DC offset removal filter and DFT filter. The algorithm utilizes a fault data of GPS time synchronized. The computed fault information is transmitted to the other side substation through communication. The digital fault locator includes MPU module, ADPU module, SIU module, and a power module. The MMI firmware and software of the fault locator was implemented.

Contralateral Submandibular Retropharyngeal Approach for Recurred High Cervical Chordoma

  • Kim, Seok-Won;Shin, Ho
    • Journal of Korean Neurosurgical Society
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    • 제39권3호
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    • pp.231-233
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    • 2006
  • The C2 level is the transition zone between the cranial and cervical spine. Because of its high position and anatomic relationship to vital structures, exposing C2 is challenging and the surgical approach is controversial. We report a of a recurred chordoma in C2 portion, occupying the osseous intraspinal portion. The patient underwent total corpectomy of C3 and gross total removal of tumor by right submandibular approach 3 years previously. We performed a lateral extrapharyngeal approach from contralateral left side with resection C2 central portion followed by gross total removal of mass and placement of graft bone. Although there was transient hypoglossal nerve palsy postoperatively, the patient had full recovery.

Multi- effect air gap membrane distillation process for pesticide wastewater treatment

  • Pangarkar, Bhausaheb L.;Deshmukh, Samir K.;Thorat, Prashant V.
    • Membrane and Water Treatment
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    • 제8권6호
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    • pp.529-541
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    • 2017
  • A multi-effect air gap membrane distillation (ME-AGMD) module for pesticide wastewater treatment is studied with internal heat recovery, sensible heat of brine recovery, number of stages and the use of fresh feed as cooling water in a single module is implemented in this study. A flat sheet polytetrafluroethylene (PTFE) membrane was used in the 4-stage ME-AGMD module. The maximum value of permeate flux could reach $38.62L/m^2h$ at feed -coolant water temperature difference about $52^{\circ}C$. The performance parameter of the module like, specific energy consumption and gain output ratio (GOR) was investigated for the module with and without heat recovery. Also, the module performance was characterized with respect to the separation efficiency of several important water quality parameters. The removal efficiency of the module was found to be >98.8% irrespective water quality parameters. During the experiment the membrane fouling was caused due to the deposition of the salt/crystal on the membrane surface. The membrane fouling was controlled by membrane module washing cycle 9 h and also by acidification of the feed water (pH=4) using 0.1M HCl solution.

A Pilot Study for Remediation of Groundwater by Surfactant -Enhanced Soil Flushing

  • Park, Jong Oh;Lee, Dal-Heui
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제21권5호
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    • pp.1-7
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    • 2016
  • The removal of non-aqueous phase liquids (NAPLs) from groundwater using pure water, via pump and treat, is quite ineffective due to their low solubility and hydrophobicity. Therefore, the objectives of pilot tests were to select potentially suitable surfactants that solubilize tetrachloroethylene (PCE) and trichloroethylene (TCE) present as contaminants and to evaluate the optimal range of process parameters that can increase the removal efficiency in surfactant-enhanced soil flushing (SESF). Used experimental method for surfactant selection was batch experiments. The surfactant solution parameters for SESF pilot tests were surfactant solution concentration, surfactant solution pH, and the flow rate of surfactant solution in the SESF pilot system. Based on the batch experiments for surfactant selection, DOSL (an anionic surfactant) was selected as a suitable surfactant that solubilizes PCE and TCE present as contaminants. The highest recovery (95%) of the contaminants was obtained using a DOSL surfactant in the batch experiments. The pilot test results revealed that the optimum conditions were achieved with a surfactant solution concentration of 4% (v/v), a surfactant solution pH of 7.5, and a flow rate of 30 L/min of surfactant solution (Lee and Woo, 2015). The maximum removal of contaminants (89%) was obtained when optimum conditions were simultaneously met in pilot-scale SESF operations. These results confirm the viability of SESF for treating PCE and TCE-contaminated groundwater.

Comparative study of analgesia with bupivacaine 0.25% versus 0.5% for third molar removal under general anesthesia

  • Dhanrajani, Parmanand;Chung, Patrick
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제16권2호
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    • pp.117-122
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    • 2016
  • Background: The aim of this study was to compare the effectiveness and duration of action of two concentrations of bupivacaine with adrenaline for postoperative pain in patients undergoing surgical removal of four third molars under general anesthesia. Methods: Sixty patients undergoing surgical removal of four wisdom teeth received bupivacaine 0.5% (n = 30) or 0.25% (n = 30). The severity of pain in the immediate recovery period and at 2 and 24 h after surgery was recorded using the visual analogue scale. Differences were assessed by box and whisper plot and the Student's t-test. Results: The analgesic effects of the 0.25% and 0.5% doses were significantly different (P = 0.022) at 30 min after surgery but not after 2 and 24 h. The difference of mean of 0.25% and 0.5% was much higher after 0.5 h but less after 2 and 24 h. Conclusions: Bupivacaine 0.5% was statistically better for pain control during the immediate postoperative period, but there was no significant difference in pain control between the two dose strengths at 2 and 24 h after surgery.

Innovative Approaches to Increase the Longevity of PRBs Containing Zero-Valent Iron

  • 이태윤;박재우;최은경;허보연
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2002년도 추계학술발표회
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    • pp.122-124
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    • 2002
  • The removal capacity of zero-valent iron for Cr(Ⅵ) was evaluated using batch kinetic tests. The rate constants for zero-valent iron dramatically increased as initial Cr(Ⅵ) concentration decreased. Generally, the reaction rates of Cr(Ⅵ) with zero-valent iron were faster than that of a biotic degradation of Cr(Ⅵ), and furthermore the reaction rates were inversely proportional to the initial Cr(Ⅵ) concentrations. After certain reaction time elapsed. no further decrease of Cr(Ⅵ) was observed, indicating a loss of iron reactivity. The loss of iron reactivity was primarily due to the passivation of iron surfaces with iron-Cr precipitates, but the reactivity of iron was recovered by adding iron-reducing bacteria. Even though the addition of bacteria itself removed Cr(Ⅵ), the combination of iron-reducing bactera and oxidized iron significantly enhanced the reaction rate for Cr(Ⅵ) removal. The results from column tests also confirmed that the innoculation of iron-reducing bacteria to the column containing completely oxidized iron partially enhanced the recovery of the iron reactivity.

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