• Title/Summary/Keyword: $P-\Delta$ analysis

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MONITORING OF REMINERALIZATION OF DECALCIFIED ENAMEL USING QUANTITATIVE LIGHT-INDUCED FLUORESCENCE-D (Quantitative light-induced fluorescence-D를 이용한 탈회 법랑질의 재석회화 감시)

  • You, Yon-Sook;Kim, Jong-Soo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.39 no.3
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    • pp.257-266
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    • 2012
  • The objective of this in vitro study was to monitor the amount of remineralization of decalcified enamel according to the number of fluoride varnish application using quantitative light-induced fluorescence-D and polarizing microscope. Artificial white lesion induced on the sound 72 teeth, $CavityShield^{TM}$ (Group I), $FluroDose^{TM}$ (Group II) and $Flor-Opal^{(R)}$ Varnish (Group III) were applied 1, 2 or 3 times every two weeks. The following results was obtained: 1. In group I, II and III, ${\Delta}L$ were increased. From regression analysis of ${\Delta}L$ by the number of application, the equation was y = 3.878x + 90.612 in group I, y = 3.133x + 37.168 in group II, and y = 3.509x + 82.322 in group III(p < 0.05). 2. In group I, II and III, ${\Delta}D$ were decreased. From regression analysis of ${\Delta}D$ by the number of application, the equation was y = -2.336x + 107.235 in group I, y = -2.158x + 101.620 in group II, and y = -1.940x + 94.806 in group III(p < 0.05). 3. The Pearson correlation value between the ${\Delta}L$ and ${\Delta}D$ was -0.673 in group I, -0.574 in group II, and -0.431 in group III(p < 0.05).

Pressure Transfer Analysis and Experimental Verification of Thin Plate Spring Type Check Valve Considering P-delta Effect (P-delta 효과를 고려한 박판 스프링 형 체크밸브의 압력전달 해석 및 실험적 검증)

  • Hwang, Yong-Ha;Nguyen, Anh Phuc;Hwang, Jai-Hyuk;Bae, Jae-Sung
    • Journal of Aerospace System Engineering
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    • v.12 no.5
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    • pp.32-39
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    • 2018
  • In this paper, the calculation of the theoretical pressure transfer ratio due to the deformation of the thin-plate spring type check valve applied to the small piezoelectric-hydraulic pump was carried out. A thin-plate check valve is a flexible body that is deformed by an external force. The deformation of the check valve affects the rate at which the chamber pressure is transferred to the load pressure. The theoretical pressure transfer ratio for each model was calculated to compare the difference between the assumption that the thin-plate check valve is a rigid body and that of the flexible body model. The P-delta effect was considered for the calculation of the pressure transfer ratio of the flexible check valve model. In addition, a verification test for the calculated pressure transfer ratio obtained by considering the deformation of the flexible check valve model was carried out. The load pressure was measured by applying a thin-plate and ball-thin plate spring type check valves, respectively. The experimental pressure transfer ratio was calculated using the respective load pressure obtained from the experiments. The validity of the pressure transfer analysis of the check valve, taking into consideration the P-delta effect, was verified by comparing it with the theoretically calculated pressure transfer ratio.

P-△ Analysis for Design of Reinforced Concrete Slender Columns (철근 콘크리트 장주 설계를 위한 P-△ 해석)

  • Lee, Jae Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.4_1
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    • pp.87-96
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    • 1992
  • Moment Magnifier Method has been generally used in estimation of total column moment induced by geometric nonlinearity for reinforced concrete slender column design, however second order analysis such as P-${\Delta}$ method has been recommended by Code for better result. Member stiffness estimation is the most significant factor for accuracy of second order analysis. Equivalent Column stiffness based on theoretically obtained moment-curvature-thrust relationship has been proposed and the analytical results of the proposed method, MacGregor-Hage Method, Furlong's Method, and Moment Magnifier Method are compared with experimentally obtained data.

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Pharmacokinetic and Pharmacodynamic Characterization of Gliclazide in Healthy Volunteers

  • Kim, Ho-Soon;Yun, Min-Hyuk;Kwon, Kwang-Il
    • Archives of Pharmacal Research
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    • v.26 no.7
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    • pp.564-568
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    • 2003
  • Pharmacokinetic and pharmacodynamic properties of gliclazide were studied after an oral administration of gliclazide tablets in healthy volunteers. After an overnight fasting, gliclazide tablet was orally administered to 11 volunteers; Additional 10 volunteers were used as a control group (i.e., no gliclazide administration). Blood samples were collected, and the concentration determined for gliclazide and glucose up to 24 after the administration. Standard pharmacokinetic analysis was carried out for gliclazide. Pharmacodynamic activity of the drug was expressed by increase of glucose concentration ($\Delta$PG), by area under the increase of glucose concentration-time curve ($AUC_{$\Delta$PG}$) or by the difference in increase of glucose concentration ($D_{$\Delta$PG}$) at each time between groups with and without gliclazide administration. Pharmacokinetic analysis revealed that $C_{max}, T_{max}$, CL/F (apparent clearance), V/F (apparent volume of distribution) and half-life of gliclazide were $4.69\pm1.38 mg/L, 3.45\pm1.11 h, 1.26\pm0.35 L/h, 17.78\pm5.27 L, and 9.99\pm2.15 h$, respectively. When compared with the no drug administration group, gliclazide decreased significantly the $AUC_{$\Delta$PG}$ s at 1, 1.5, 2, 2.5, 3 and 4 h (p<0.05). The $\Delta$PGs were positively correlated with $AUC_{gliclazide}$ at 1 and 1.5 h (p<0.05), and the correlation coefficient was maximum at 1 h (r = 0.642) and gradually decreased at 4 h after the administration. The $AUC_{$\Delta$PG}$s were positively correlated with $AUC_{gliclazide}$ at 1, 2, 3 and 4 h (p<0.05), and the maximum correlation coefficient was obtained at 2 h (r=0.642) after the administration. The $D_{$\Delta$PG}$ reached the maximum at 1 h, remained constant from 1 h to 3 h, and decreased afterwards. Therefore, these observations indicated that maximum hypoglycemic effect of gliclazide was reached at approximately at 1.5 h after the administration and the effect decreased, probably because of the homeostasis mechanism, in health volunteers.

Evaluation of Detection Ability of a Quantitative Light-Induced Fluorescence Digital Device for Initial Secondary Caries Lesion (Quantitative Light-Induced Fluorescence-Digital을 이용한 와동 내벽의 초기 이차우식병소 탐지 능력 평가)

  • Kim, Young Seok
    • Journal of dental hygiene science
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    • v.17 no.2
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    • pp.116-122
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    • 2017
  • The purpose of this study was to evaluate the detection ability of secondary caries using qunatitative light-induce fluorescence-digital (QLF-D) device. Twenty bovine teeth with cavity on surface were demineralized during 21 days for secondary caries lesion of cavity wall. After 21 days, cavity was filled using composite resin and cut the specimen in half with disc. Fluorescence loss of lesion on surface by time flow, cross sectional lesion, and lesion of filled or unfilled surface were analyzed using analysis software. ${\Delta}F$ (value of fluorescence loss) of the lesion on surface assessed by the QLF-D increased significantly over time up to 21 days. And ${\Delta}F$ value of lesion of filled surface is significantly lower than that of unfilled surface (p<0.001). ${\Delta}F$ of filled surface is 1.31 times of cross section lesion. The correlation of between ${\Delta}F$ of filled surface lesion and ${\Delta}F$ of cross section lesion was showed low agreement (0.026) and correlation of between ${\Delta}F$ of unfilled surface lesion and ${\Delta}F$ of cross section lesion was showed high agreement (0.613). In conclusion, secondary caries can be detected on surface using QLF-D. However, interference of fluorescence of filling material is the points to be especially considered for exact analysis of secondary caries lesion.

Ultimate Resisting Capacity of RC Columns Considering P-$\Delta$ Effect (P-$\Delta$ 효과를 고려한 RC 기둥의 극한저항력 산정)

  • 곽효경;김진국;김한수
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.1
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    • pp.105-116
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    • 2002
  • In this paper, an analytical model to predict the resisting capacity of slender RC columns is introduced. Material and geometric nonlinearities are taken into account, and the layer approach is adopted to simulate the different material properties across the sectional depth. On the basis of the obtained numerical analysis results, an improved design equation as a function of concrete strength, slenderness ratio, steel ratio and eccentricity for slender RC columns, which can be used effectively in the preliminary design stage, is introduced. Finally, P-M interaction diagrams constructed by the introduced equation are compared with the ACI method with the objective of establishing the relative efficiencies of the introduced equation.

Evaluation of the Lateral Ultimate Strength of Steel Moment Resisting Frames under Axial and lateral Forces (수평력과 축력을 받는 강골조의 최대수평내력 평가)

  • Kim, Jong Sung
    • Journal of Korean Society of Steel Construction
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    • v.11 no.1 s.38
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    • pp.69-78
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    • 1999
  • When the lateral forces are applied to a frame, columns in the frame are usually accompanied with sidesway. If this sidesway is large, the frame is subjected to buckling and an early yielding of members which reduces the overall frame stiffness. In this study, numerical analysis of frames were conducted to evaluate the ultimate lateral strength of steel moment resisting frames permitted to sidesway under axial and lateral forces, and develope the procedure for determining the limits of column slenderness ratios. In the numerical analysis, the effects of the relative stiffness ratio between beam and column, deterioration of overall frame stiffness, slenderness ratio and loading conditions were considered. The elasto-plastic analysis method in which the $P-{\Delta}$effect is implemented, presented by the author previously, was adopted in the analysis. Incremental lateral forces were applied to the frame under constant axial loads and the generalized inverse is employed for the post-ultimate behavior.

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Increased Frontal Gamma and Posterior Delta Powers as Potential Neurophysiological Correlates Differentiating Posttraumatic Stress Disorder from Anxiety Disorders

  • Moon, Sun-Young;Choi, Yoo Bin;Jung, Hee Kyung;Lee, Yoonji Irene;Choi, Soo-Hee
    • Psychiatry investigation
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    • v.15 no.11
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    • pp.1087-1093
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    • 2018
  • Objective Posttraumatic stress disorder (PTSD) is distinct from anxiety disorders in its etiology and clinical symptomatology, and was reclassified into trauma- and stressor-related disorders in DSM-5. This study aimed to find neurophysiological correlates differentiating PTSD from anxiety disorders using resting-state quantitative electroencephalography (qEEG). Methods Thirty-six patients with either PTSD or acute stress disorder and 79 patients with anxiety disorder were included in the analysis. qEEG data of absolute and relative powers and patients' medication status on the day of qEEG examination were obtained. Electrodes were grouped into frontal, central, and posterior regions to analyze for regional differences. General linear models were utilized to test for group differences in absolute and relative powers while controlling for medications. Results PTSD patients differed from those with anxiety disorders in overall absolute powers [F(5,327)=2.601, p=0.025]. Specifically, overall absolute delta powers [F(1,331)=4.363, p=0.037], and overall relative gamma powers [F(1,331)=3.965, p=0.047] were increased in PTSD group compared to anxiety disorder group. Post hoc analysis regarding brain regions showed that the increase in absolute delta powers were localized to the posterior region [F(1,107)=4.001, p=0.048]. Additionally, frontal absolute gamma powers [F(1,107)=4.138, p=0.044] were increased in PTSD group compared to anxiety disorder group. Conclusion Our study suggests increased overall absolute delta powers and relative gamma powers as potential markers that could differentiate PTSD from anxiety disorders. Moreover, increased frontal absolute gamma and posterior delta powers might pose as novel markers of PTSD, which may reflect its distinct symptomatology.

Interpretation of Blood Gas Analysis During Hypothermic Cardiopulmonary Bypass (저체온 체외순환시 혈액가스분석의 판독과 체온과의 상관관계)

  • Song, Sun-Ok
    • Journal of Yeungnam Medical Science
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    • v.6 no.1
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    • pp.121-131
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    • 1989
  • The temperature-corrected values of blood gas analysis were compared to uncorrected values in 40 cases of open heart surgery under moderate hypothermic cardiopulmonary bypass. The results were as follows. 1. The corrected value of pH was significantly higher than uncorrected value, and it's relationship was ${\Delta}pH=-0.015$ ${\Delta}Temp+0.005$(r=0.81, P<(0.01). 2. The corrected value of $PCO_2$ was lower than uncorrected value, and it's relationship was ${\Delta}PCO_2=1.11$ ${\Delta}Temp+1.81$(r=0.50, P<0.01). 3. The corrected value of $PO_2$ was lower than uncorrected value, and it' s relationship was ${\Delta}PO_2=5.21$ ${\Delta}Temp-1.45$(r=0.32, P<0.01). But there was no clinical significance. 4. The corrected values of $HCO_{3^-}$, base excess, $CO_2$ content and oxygen saturation were similar with uncorrected values. In summery, the values of pH and $PCO_2$were significantly changed by temperature-correction. Because of the neutral point of water (pH=pOH) rises as temperature falls and it change in parallel with the changes in blood pH, a corrected pH of 7.4, $PaCO_2$ of 40mmHg during deep hypothermia would reflect a profound respiratory acidosis. Therefore, the use of the uncorrected value at $37^{\circ}C$ is more preferable and valid means of assessing acid-base management regardless of actual patient temperature.

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