• Title/Summary/Keyword: $NO_2$ reduction

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The Experiment of Grid Characteristics for High-voltage Radiography of Chest (흉부촬영시 관전압과 선질에 따른 적절한 격자의 선택을 위한 실험)

  • Kim, Jung-Min;Ahn, Bong-Seon
    • Journal of radiological science and technology
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    • v.15 no.2
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    • pp.31-36
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    • 1992
  • Grids can improve the diagnostic quality of chest radiography by trapping the greater part of scattered radiation thus providing more detailed. chest radiographic images. It is most effective mathod of reduce the scatter ratio but must increase the expour factor. The benefit of use of grid is improve the contrast and the loss is increase of patient dose. In chest radiography especially hard quality high voltage radiography it will have to be considered to select the optimum grid with view point of benefit and loss. In this experiment, author got some result of characteristics about 4 different grids with film method. 1. There was no difference the scatter ratio in case of no grid and the scatter ratio was about 60%. 2. 16 : 1 grid was excellent of scatter reduction factor in high voltage chest radiography, next was 10 : 1, CROSS, MICRO FINE grid have low scatter reduction rate compare to 16:1, 10:1 grid. 3. The bucky factor of CROSS grid in accordance of kVp was find out the highest in 4 grids, on the contraly 10 : 1 grid was profitable to the exposure does. 4. With careful consideration in the point of scatter reducion rate and bucky factor, author suggest the 10 : 1 linear grid on the use of chest radiography in $80{\sim}120\;kVp$, 16 : 1 grid in $120{\sim}140\;kVp$.

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Effect of Captopril on Renal Function in Dog (개의 신장기능에 미치는 Captopril의 영향)

  • Ko, Suk-Tai;Lee, Min-Jae
    • YAKHAK HOEJI
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    • v.34 no.2
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    • pp.88-101
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    • 1990
  • Captopril, angiotensin converting enzyme (ACE) inhibitor, when given intravenously in dog, elicited the diuretic action along with the increases of glomerular filtration rates (GFR), renal plasma flow (RPF) and osmolar clearances (Cosm) with no changes of free water clearnces ($C_{H_2O}$), and then captopril produced the enlargement of excretion rates of electrolytes in urine and the reduction of reabsorption rates of electrolytes in renal tubles. Captopril, when given into a renal artery, exhibited no changes of renal function in the experinental kidney, whereas diuretic action with the same mechanism as shown in intravenous captopril in control kidney. Captopril, when injected into a carotid artery, showed increases in rates of urine flow in a small does which did not affect on renal action when it was administered intravenusly. Diuretic action induced by captopril was not influenced by renal artery denervation, propranolol and angiotensin II inhibiters. Above results suggest that captopril produced diuretic action along with renal hemodynamic changes by slight contraction of vas efferense and reduction of reabsorption rate of electrolytes in renal tubules, especilly distal tubules, that may be mediatedby endogenous substances.

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Study on Loss Reduction for Tilting Disk Check Valve Installed in Piping System (배관용 틸팅디스크 체크밸브의 손실저항 절감에 관한 연구)

  • Kim, J.H.;Park, J.H.;Lee, H.S.;Nam, S.H.;Hwang, S.H.
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2006.06a
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    • pp.327-328
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    • 2006
  • In generally, under the influence of over-pressure drop, serious problems such as cavitation, choked flow, flashing and vibration has been coming around the tilting disk check valve. A PIV experiment to examine the cause of energy loss has been performed and the improvement configuration of valve seat based on this visualization results is proposed. In the visualization results, flows in the piping system became instability under the influence of the shape of boss. This unstable flows induces sudden pressure drop in the piping system. So, we change the configuration of boss as a streamlined design to be stabilized the flows. A pressure measurement has been performed to know that the influence of the configuration change. In result, the rate of pressure loss reduction is about 22% at the position of No. 2 and 24.2% at the position of No. 6 in comparison with pre-improved shape.

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A PIV Study on Loss Reduction for Tilting Disk Check Valve Installed in Piping System of Water Supply by PIV (PIV에 의한 상수도 배관용 틸팅디스크 체크 밸브의 손실저감에 관한 연구)

  • Kim, B.S.;Kim, J.H.;Lee, J.Y.;Kim, J.G.;Lee, Y.H.
    • 유체기계공업학회:학술대회논문집
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    • 2003.12a
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    • pp.577-582
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    • 2003
  • In generally, under the influence of over-pressure drop, serious problems such as cavitation, choked flow, flashing and vibration has been coming around the tilting disk check valve. A PIV experiment to examine the cause of energy loss has been performed and the improvement configuration of valve seat based on this visualization results is proposed. In the visualization results, flows in the piping system became instability under the influence of the shape of boss. This unstable flows induces sudden pressure drop in the piping system. So, we change the configuration of boss as a streamlined design to be stabilized the flows. A pressure measurement has been performed to know that the influence of the configuration change. In result, the rate of pressure loss reduction is about 22% at the position of No. 2 and 24.2% at the position of No. 6 in comparison with pre-improved shape.

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A Study on the Dynamic Stability of a Flexible Missile with Mass Variation (질량변화를 갖는 유연한 미사일의 동적 안정성에 관한 연구)

  • Ryu, Bong-Jo
    • Journal of the Korean Society for Precision Engineering
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    • v.8 no.4
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    • pp.107-117
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    • 1991
  • The dynamic stability problem of nonconservative system is one of the important problems. In this study, flexible missile with mass variation is regarded as a free Timoshenko beam subjected to a controlled follower force. The stability was studied numerically through the finite element method. Through the study, the obtained results are as follows: [1] Without force direction control (1) In the case of no mass reduction, the existence of concentrated mass increases critical follower force. (2) Mass reduction rate of the beam slightly effects on the change of critical follower force. [2] With force direction control (1) Shear deformation parameter S contributes insignificantly to the force at instability when $S{\geq}10^4$. (2) With mass variation, increase of concentrated mass increases critical follower force at instbility. (3) The type of promary instability is determined by the sensor location.

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Sub-1.2-V 1-Gb Mobile DRAM with Ultra-low Leakage Current (극저 누설전류를 가지는 1.2V 모바일 DRAM)

  • Park, Sang-Kyun;Seo, Dong-Il;Jun, Young-Hyun;Kong, Bai-Sun
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.433-434
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    • 2007
  • This paper describes a low-voltage dynamic random-access memory (DRAM) focusing on subthreshold leakage reduction during self-refresh (sleep) mode. By sharing a power switch, multiple iterative circuits such as row and column decoders have a significantly reduced subthreshold leakage current. To reduce the leakage current of complex logic gates, dual channel length scheme and input vector control method are used. Because all node voltages during the standby mode are deterministic, zigzag super-cutoff CMOS is used, allowing to Preserve internal data. MTCMOS technique Is also used in the circuits having no need to preserve internal data. Sub-1.2-V 1-Gb mobile DDR DRAM employing all these low-power techniques was designed in a 60 nm CMOS technology and achieved over 77% reduction of overall leakage current during the self-refresh mode.

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Probiotics in Drinking Water Alleviate Stress of Induced Molting in Feed-deprived Laying Hens

  • Khajali, Fariborz;Karimi, S.;Qujeq, D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.8
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    • pp.1196-1200
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    • 2008
  • An experiment was conducted to evaluate the physiological changes of laying hens subjected to feed removal during induced molting while received probiotics in the drinking water. Post-molt performance and egg quality criteria were also studied. Ninety 78-week-old Hy-line W36 laying hens were divided into two treatment groups according to equal body weight and subjected to induced molting by continuous feed removal until around 30% BW reduction. The experiment lasted 12 wks consisting of 4-wk molting and 8-wk post-molt periods. Treatment 1 received no probiotics and was considered as the control. Treatment 2 was similar to the control except that hens received probiotics in the drinking water at 400 mg/L during feed deprivation. The results indicated that hens in both groups went out of production by Day 5. However, hens received probiotics reached 5 and 50% egg production sooner than the control (30 and 52 days vs. 31 and 54 days). Starvation during molting increased heterophil to lymphocyte (H/L) ratio, hematocrit and plasma T4 and $Na^+$ levels while plasma T3 and Cl- levels were decreased. Probiotics had no significant impact on BW reduction during molt. Post-molt egg production and egg mass were higher in hens which previously received probiotics, but these responses were not significant. However, feed conversion ratio was significantly better in hens which received probiotics. Hematocrit, plasma thyroid hormone concentrations (T3 and T4) and plasma $Na^+$, $K^+$ and Cl- levels during molting were not significantly influenced by supplementation of probiotics. However, H/L ratio showed a significant (p<0.05) reduction in birds which received probiotics suggesting beneficial effects of this product for feed-deprived laying hens. No significant difference was observed in post-molt egg quality criteria.

Good functional results with open reduction and internal fixation for locked posterior shoulder fracture-dislocation: a case series

  • Nicolas Moran;Michael Marsalli;Mauricio Vargas;Joaquin De la Paz;Marco Cartaya
    • Clinics in Shoulder and Elbow
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    • v.25 no.4
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    • pp.288-295
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    • 2022
  • Background: There is no standardized therapeutic strategy for locked posterior shoulder fracture-dislocation (PSFD), and no consensus exists on the analysis of preoperative factors. This retrospective study aimed to evaluate functional results and complications in a series of PSFD cases managed with open surgical treatment. Methods: Patients diagnosed with locked PSFD who underwent open surgical treatment with reduction and osteosynthesis between April 2016 and March 2020 were included. All participants were treated with open reduction and internal fixation. Functional assessment used the modified University of California, Los Angeles (UCLA) mod scale, American Shoulder and Elbow Surgeons (ASES) questionnaire, subjective shoulder value (SSV), and visual analog scale (VAS). Complications were evaluated clinically and radiologically by X-ray and computed tomography. Results: Twelve shoulders were included (11 patients; mean age, 40.6 years; range, 19- 62 years). The mean follow-up duration was 23.3 months (range, 12-63 months). The UCLA mod, ASES, SSV, and VAS scores were 29.1±3.7, 81.6±13.5, 78±14.8, and 1.2±1.4 points, respectively. The overall complication rate was 16.6%, with one case of post-traumatic stiffness, 1 case of chronic pain, and no cases of avascular necrosis. Conclusions: Open surgical treatment of locked PSFD can achieve good functional results. A correct understanding of these injuries and good preoperative planning helped us to achieve a low rate of complications.

Cardiac dose reduction with breathing adapted radiotherapy using self respiration monitoring system for left-sided breast cancer

  • Sung, KiHoon;Lee, Kyu Chan;Lee, Seung Heon;Ahn, So Hyun;Lee, Seok Ho;Choi, Jinho
    • Radiation Oncology Journal
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    • v.32 no.2
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    • pp.84-94
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    • 2014
  • Purpose: To quantify the cardiac dose reduction during breathing adapted radiotherapy using Real-time Position Management (RPM) system in the treatment of left-sided breast cancer. Materials and Methods: Twenty-two patients with left-sided breast cancer underwent CT scans during breathing maneuvers including free breathing (FB), deep inspiration breath-hold (DIBH), and end inspiration breath-hold (EIBH). The RPM system was used to monitor respiratory motion, and the in-house self respiration monitoring (SRM) system was used for visual feedback. For each scan, treatment plans were generated and dosimetric parameters from DIBH and EIBH plans were compared to those of FB plans. Results: All patients completed CT scans with different breathing maneuvers. When compared with FB plans, DIBH plans demonstrated significant reductions in irradiated heart volume and the heart $V_{25}$, with the relative reduction of 71% and 70%, respectively (p < 0.001). EIBH plans also resulted in significantly smaller irradiated heart volume and lower heart $V_{25}$ than FB plans, with the relative reduction of 39% and 37%, respectively (p = 0.002). Despite of significant expansion of lung volume using inspiration breath-hold, there were no significant differences in left lung $V_{25}$ among the three plans. Conclusion: In comparison with FB, both DIBH and EIBH plans demonstrated a significant reduction of radiation dose to the heart. In the training course, SRM system was useful and effective in terms of positional reproducibility and patient compliance.

School Dietitian Awareness, Practice, and Sodium Reduction Plan in School Meal Service (학교 급식 영양(교)사의 나트륨 저감화 인식도, 실천도 및 저감화 방안)

  • Kim, Eun Kyung;Kim, Hae Young
    • Korean journal of food and cookery science
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    • v.32 no.2
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    • pp.222-232
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    • 2016
  • Purpose: Sodium intake in school meals is very high. Accordingly, many health problems have emerged. The objective of this study was to assess school dietitian's awareness and practice of sodium contents in urban and rural locations schools and suggest sodium reduction plan in school meal service. Methods: A total of 524 nationwide school dietitians from elementary, middle, and high schools in south Korea were surveyed using questionnaires to determine their awareness and practicing behavior for reducing high-salt contents in meals. Sodium reduction plan was then suggested accordingly. Results: Most school dietitians (83%, n=436) were aware of the necessities of sodium reduction in school meals. They were aware of optimum sodium levels at 700-1000 mg. However, the percentages of dietitians who had practicing behavior of using measuring utensils for seasoning were 20.7% (n=108), 14.9% (n=78), and 13.5% (n=71) in elementary, middle, and high schools, respectively (p<0.001). Dietitians in urban elementary and middle schools had significantly (p<0.01) higher practicing behavior of using measuring utensils compared to those in rural locations. Considering low levels of soup contents with high amount of leftover, the desirable soup portions to be reduced were '50-100 mL' (n=66, 12.7%) for elementary school and '100-150 mL' for middle school (n=62, 12.0%) and high school (n=57, 11.0%, p<0.001). Conclusion: Dietitians' awareness for sodium reduction was high but their practicing behavior was relatively low. Thus, continuous efforts are required to develop reduced-sodium menu by promoting the use of measuring utensils when preparing meals and by planning no soup meal day or educating students and teachers about the importances of reducing sodium in school meals.