• Title/Summary/Keyword: Effective Dose Rate

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Performance Evaluation of Lab-scale High Rate Coagulation System for CSOs Treatment (강우유출수의 신속한 처리를 위한 고속응집시스템의 성능 평가 -실험실 규모 장치를 중심으로-)

  • Gwon, Eun-Mi;Oh, Seok-Jin;Cho, Seong-Ju;Lee, Seng-Chul;Ha, Sung-Ryong;Lim, Chea-Hoan;Park, Ji-Hoon;Kang, Seon-Hong
    • Journal of Korean Society of Water and Wastewater
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    • v.24 no.5
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    • pp.629-639
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    • 2010
  • To evaluate the performance of high rate coagulation system(HRCS) for CSOs treatment, fundamental function of lab scale HRCS has been tested by using the Jar tester and lab scale HRCS. The optimum pH dose by Streaming Current value was found in the range of 5.3~6.0 in Fe(III), and in the range of 5.8~6.6 in Al(III) and the optimum chemical dose were 0.44mM of $Al_2(SO_4)_3$ and 0.93mM of $FeCl_3$. The removal efficiencies at optimum $Al_2(SO_4)_3$ dose were 75%($TCOD_{Cr}$), 97%(TP), 95%(SS) and 96%(turbidity), respectively. And the removal efficiency of particles with less than $5{\mu}m$ of diameter was 70% and that of particles with higher than $5{\mu}m$ of diameter was 90%. The optimum alum dose in lab scale HRCS was 150mg/L, and the treatment efficiency was the best with addition of 1.0mg/L polymer. The effect of Micro sand addition was not clear, because the depth of the sediment tank in lab scale HRCS was not long enough. But the HRT of this lab scale HRCS was able to be shorten less then 7 minutes by adding the micro sand. The surface loading rates with respect to using different chemicals were 0.43m/h with alum only, 5.78m/h with alum and polymer and 6.22m/h with alum, polymer and micro sand. As a result, HRCS using coagulant, polymer and micro sand developed in this study was evaluated to be very effective for CSOs treatment.

HIGH DOSE RATE BRACHYTHERAPY IN PRIMARY AND RECURRENT TONGUE CANCER (고선량율 근접 방사선치료법을 이용한 원발성 및 재발된 설암의 치료)

  • Lee, Ui-Lyong;Lee, Jong-Ho;Choung, Pill-Hoon;Kim, Myung-Jin;Park, Joo-Yong;Choi, Sung-Weon;Cho, Kwan-Ho
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.28 no.5
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    • pp.470-476
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    • 2006
  • Low-dose rate brachytherapy(LDR) has been effective modality for treatment of oral cancer. But the disadvantage of LDR is radioexposure of medical staff. To overcome this problem, high dose rate(HDR) brachytherapy has been developed. Our study evaluates the outcomes of patients with tongue cancer as treated by HDR brachytherapy. Between 2002 and 2005, eight patients with carcinoma of the tongue were treated with HDR brachytherapy. Five patients had AJCC stage I or II disease and the remaining three patients had AJCC stage III or IV. The male-to-female ratio was 2:6 and the mean age was 60.1 years (range: 21-80 years).The median follow-up time was 23.8 months (range: 7-55 months). There was no local failure until now. Three patients showed some complications. Two patients showed soft tissue necrosis. There was no bone sequela in all cases. Our experience in treating tongue cancer with HDR brachytherapy is encouraging, because it gave a satisfactory local control. Prospective studies are necessary to delineate the optimum indication for this treatment modality and long-term outcome.

Implementation of Fire Risk Estimation System for various Fire Situations using Multiple Sensors (다중 센서들을 이용한 다양한 화재 상황의 위험도 추정 시스템 개발)

  • Lee, Kwangjae;Lee, Youn-Sung
    • Journal of Sensor Science and Technology
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    • v.25 no.6
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    • pp.394-398
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    • 2016
  • In this paper, a fire detection system based on quantitative risk estimation is presented. Multiple sensors are used to build a comprehensive indicator that represents the risk of fire quantitatively. The proposed fire risk estimation method consists of two stages which determines the occurrence of fire and estimates the toxicity of the surveillance area. In the first stage, fire is reliably detected under diverse fire scenarios. The risk of fire is estimated in the second stage. Applying Purser's Fractional Effective Dose (FED) model which quantitates harmfulness of toxic gases, the risk of the surveillance area and evacuation time are calculated. A fire experiment conducted using four different types of combustion materials for the verification of the system resulted in a maximum error rate of 12.5%. By using FED calculation and risk estimation methods, the proposed system can detect various signs of fire faster than conventional systems.

Fibrinolysis with Lower Dose Urokinase in Patients with Complicated Parapneumonic Effusion

  • Lee, Seul;Lee, Heock;Lee, Dong Hyun;Kang, Bo Hyoung;Roh, Mee Sook;Son, Choohee;Kim, Sung Hyun;Lee, Hyun-Kyung;Um, Soo-Jung
    • Tuberculosis and Respiratory Diseases
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    • v.84 no.2
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    • pp.134-139
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    • 2021
  • Background: Intrapleural urokinase is one of the most widely used fibrinolytic agents in the treatment of complicated parapneumonic effusion (CPPE). However, little research has been performed on the optimal urokinase dosage. The aim of this study was to evaluate the treatment efficacy of half dose urokinase compared with conventional dose urokinase. Methods: We retrospectively enrolled 92 patients with CPPE or empyema who underwent intrapleural urokinase treatment at two tertiary hospitals. Patients received antibiotics, chest tube drainage, and other treatments as part of routine care. The primary outcome was the treatment success rate in the half dose urokinase group (50,000 IU daily for maximal 6 days) and the conventional dose urokinase group (100,000 IU daily). Treatment success was defined as clinical and radiological improvements without surgical treatment or re-admission within one month. Results: Forty-four patients received half dose urokinase, whereas 48 patients were treated with conventional dose urokinase. Both groups were relatively well matched at baseline, excluding higher serum white blood cell count and higher empyema prevalence in the half dose urokinase group. The treatment success rate was not different between the two groups (p=0.048). There were no differences in the rate of in-hospital death and surgical treatment, hospitalization duration, and indwelling catheter duration. In the multivariate analysis, urokinase dose was not a predictor of treatment success. Conclusion: Half dose intrapleural urokinase is equally effective conventional dose urokinase in treating patients with CPPE or empyema.

Consideration about Radiological Technology Student's Frequent Workers Exposure Dose Rate (방사선과 재학생의 수시출입자 방사선 피폭선량에 대한 고찰)

  • Park, Hoon-Hee
    • Journal of radiological science and technology
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    • v.41 no.6
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    • pp.573-580
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    • 2018
  • The Nuclear Safety Commission amended the Nuclear Safety Act by strengthening the safety management system for the frequent workers to the level of radiation workers. And students entering radiation management zones for testing and practical purposes are subject to frequent workers. It is inevitable that this will incur additional costs. In this paper, the validity of the amendment to the Nuclear Safety Act was to be assessed in terms of radiation protection. Study subjects are from 2014 to 2016, among university students in Seong-nam Korea and comparisons for analyses were made taking into account variables that are differences in annual, practical types, on-class and clinical practice students exposure dose. The analysis showed that exposures between on-class and clinical practice received were less than the annual dose limit of 1 mSv for the public. Then, some alternatives that excluding from frequent workers during on-class practice or mitigating the frequent workers' safety regulation for only on-class frequent workers can be considered. Optimization is how rational is the reduction in exposure dose to the costs required. Therefore, the results are hardly considered for optimization. If the data accumulated, it could be considered that the revision of the act could be evaluated and improved.

Measurement of Absorbed Dose at the Tissue Surface from a Plain $^{90}Sr+^{90}Y$ Beta Sources (조직 표면에서의 베타선 흡수선량 측정)

  • Hah, Suck-Ho;Kim, Jeong-Mook;Yook, Chong-Chul
    • Journal of Radiation Protection and Research
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    • v.16 no.2
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    • pp.17-26
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    • 1991
  • Beta ray $(^{90}Sr+^{90}Y)$ absorbed dose at tissue surface was measured from the distance of 30cm by use of extrapolation chamber. In the measurement, following factors were considered: effective area of collecting electrode, polarity effect, ion recombination and window attenuation. The measured absorbed dose rate at tissue surface was $1.493{\mu}Gy/sec$ with ${\pm}2.9%$.

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Flavonoids of Rosa roxburghii Tratt Act as Radioprotectors

  • Xu, Ping;Zhang, Wen-Bo;Cai, Xin-Hua;Lu, Dan-Dan;He, Xiao-Yang;Qiu, Pei-Yong;Wu, Jiao
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.19
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    • pp.8171-8175
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    • 2014
  • Background: To study the radioprotective effects of flavonoids from Rosa roxburghii Tratt (FRT). Materials and Methods: The radioprotective effects of FRT were investigated by examining cell viability, 30-day survival of mice and the number of colony-forming units in spleen (CFU-S) after total-body 60Co irradiation. Results: The survival rates of irradiated cells gradually increased with increasing concentrations of FRT. The survival rate was the highest at 87% with a concentration of $30{\mu}g/mL$. Pretreatment with FRT was needed to realize its radioprotective activity in mice at the dose of 60 mg/kg. With the increasing doses of 30 mg/kg, 60 mg/kg and 120 mg/kg, the numbers of CFU-S increased, and were significantly different compared with the control group. Conclusions: Pretreatment with FRT prior to irradiation resulted in significantly higher cell survival at 24 h after 5 Gy radiation, increased 30-day survival in mice after exposure to a potentially lethal dose of 8 Gy, and resulted in a higher number of CFU-S in mice after exposure to a dose of 6 Gy. These results collectively indicate that FRT is an effective radioprotective agent.

Estimation of natural radionuclide and exhalation rates of environmental radioactive pollutants from the soil of northern India

  • Devi, Vandana;Chauhan, Rishi Pal
    • Nuclear Engineering and Technology
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    • v.52 no.6
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    • pp.1289-1296
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    • 2020
  • The estimation of radioactivity level is vital for population health risk assessment and geological point of view and can be evaluated as rate of exhalation and source concentration (226Ra, 232Th and 40K). The present study deals with the soil samples for investigation of radionuclides content and exhalation rates of radon -thoron gas from different sites in northern Haryana, India. Absorbed dose and associated index estimated in the present study are the measures of environmental radioactivity to inhalation dose. Effective doses received by different tissues and organs by considering different occupancy and conditions are also measured. Exhalation rates of radon and thoron are measured with active scintillation monitors based on alpha spectroscopy namely scintillation radon (SRM) and thoron (STM) monitors respectively. Sample height was optimized before measurement of thoron exhalation rate using STM. Average values of radon and thoron exhalation are found 16.6 ± 0.7 mBqkg-1h-1 and 132.1 ± 2.6 mBqm-2s-1 respectively. Also, a simple approach was also adopted, to evaluate the thoron exhalation which accomplished a lot of challenges, the results are compared with the data obtained experimentally. The study is useful in the nationwide mapping of radon and thoron exhalation rates for understanding the environmental radioactivity status.

Effect of Hand Massage on Nausea, Vomiting and Anxiety in Childhood with Leukemia on Chemotherapy (백혈병 환아의 항암화학요법시 손마사지가 오심, 구토 및 불안에 미치는 효과)

  • Han Ji-Eun;Moon Young-Im;Park Ho-Ran
    • Child Health Nursing Research
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    • v.11 no.4
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    • pp.456-464
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    • 2005
  • Purpose: To determine the effects of hand massage on nausea and vomiting, and anxiety in children with Iymphocytic leukemia receiving high dose chemotherapy. Method: The children were assigned to an experimental group(15) or a control group(15). All of the children were diagnosed with acute Iymphocytic leukemia and admitted for high dose chemotherapy at C University Medical Center in Seoul. The hand massage was performed for 10 minutes twice a day over three days. To measure the effects of hand massage, the Index of Nausea and Vomiting by Rhodes et al. and the State-Trait Anxiety Inventory for children by Spielberger were used. The level of anxiety was measured by systolic blood pressure, diastolic blood pressure, and pulse rate. Results: The score for nausea and vomiting decreased in the experimental group. State anxiety for the experimental group was significantly more positive than for the control group at the 2nd measurement. There was a significant difference in systolic blood pressure between the two groups. The level of diastolic blood pressure in the two groups decreased significantly over time. Conclusion: Hand massage could be effective in decreasing nausea and vomiting, state anxiety, pulse rate and blood pressure in children with acute leukemia receiving high dose chemotherapy.

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Important Radionuclides and Their Sensitivity for Ground water Pathway of a Hypothetical Near-Surface Disposal Facility

  • Park, J. W.;K. Chang;Kim, C. L.
    • Nuclear Engineering and Technology
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    • v.33 no.2
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    • pp.156-165
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    • 2001
  • A radiological safety assessment was performed for a hypothetical near-surface radioactive waste repository as a simple screening calculation to identify important nuclides and to provide insights on the data needs for a successful demonstration of compliance. Individual effective doses were calculated for a conservative ground water pathway scenario considering well drilling near the site boundary. Sensitivity of resulting ingestion dose to input parameter values was also analyzed using Monte Carlo sampling. Considering peak dose rate and assessment time scale, C-14 and T-129 were identified as important nuclides and U-235 and U-238 as potentially important nuclides. For C-14, the dose was most sensitive to Darcy velocity in aquifer The distribution coefficient showed high degree of sensitivity for I-129 release.

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