• Title/Summary/Keyword: Relative stability

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Stability of Atenolol Tablet After Dispensing to Powder form at Community Pharmacies (근린약국에서 산제로 조제된 아테놀올정의 안정성)

  • Yong, Chul-Soon;Choi, Han-Gon;Rhee, Jong-Dal;Yoo, Bong-Kyu
    • Journal of Pharmaceutical Investigation
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    • v.34 no.4
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    • pp.299-303
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    • 2004
  • Prescription filling in powder form is performed in community pharmacy practice to adjust dose for children and patients who cannot swallow whole tablet. However, there are few reports regarding the stability of the active ingredient and possible microbial growth after the medication is dispensed to powder form. This study examined the stability of atenolol, an antihypertensive agent, and microbial growth in the unit dose pouches dispensed at twenty-one community pharmacies located in Taegu area. Randomly chosen first unit dose pouch contained 77.4% of the prescribed dose of the drug and there were only four community pharmacies that dispensed the drug within 10% deviation from the dose prescribed by physician. Surprisingly, there were three community pharmacies that dispensed the drug with greater than 40% deviation, which may pose a major concern regarding the efficacy and safety of the drug prescribed for the treatment of hypertension. Atenolol content during a month did not indicate significant change, showing 5.4%, 4.3%, and 3.3% of decrease in 50%, 80%, and 90% relative humidity conditions, respectively. Microbiological examination during a month showed less than 0.5 microorganism in high power field (hpf) in all the relative humidity conditions tested. Based on this study, pharmacy practice in community pharmacy needs to be rigorously regulated to ensure that the dose of the prescribed drug is properly incorporated into the unit dose pouch dispensed as powder form.

Functional Properties of Mucilage and Pigment Extracted from Opuntia ficus-indica (선인장 열매로부터 추출된 점질물 및 색소의 기능성)

  • Lee, Sam-Pin;Whang, Key;Ha, Young-Duck
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.5
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    • pp.821-826
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    • 1998
  • Functional properties of mucilage and pigment extracted from Opuntia ficus-indica var. saboten were determined at various temperatures, pHs and alcohol concentrations. The crude mucilage extracted from pickly pear showed pH 4.2, 0.14% total acidity and 8.1% total soluble solid content(w/w, wet basis). Polysaccharide was purified from mucilage extract by isopropanol precipitation. Intrinsic viscosity of polysaccharide was 18.1dl/g and decreased with increasing KCl concentration. Relative viscosity and color stability of mucilage extract were determined with capillary viscometer and spectrophotometer at 534nm, respectively. In additions of 1~20%(v/v) ethanol, the red pigment of mucilage extract was very stable, but relative viscosity, increased gradually. For heating above 7$0^{\circ}C$, the stability of red pigment decreased drastically, but rheological property of mucilage was not changed. During storage, the red pigment was extremely unstable at above pH 8.3. At both pH 3.0 and pH 4.2, the red pigment was the most stable at 4$^{\circ}C$ for 18 days. In the case of storage at 37$^{\circ}C$, pigment of mucilage extract at pH 3.0 was destroyed more quickly than that at pH 4.2. Natural mucilage extract(pH 4.2) showed the good stability of red pigment at 3$0^{\circ}C$ for 10 days.

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A study of glass and carbon fibers in FRAC utilizing machine learning approach

  • Ankita Upadhya;M. S. Thakur;Nitisha Sharma;Fadi H. Almohammed;Parveen Sihag
    • Advances in materials Research
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    • v.13 no.1
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    • pp.63-86
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    • 2024
  • Asphalt concrete (AC), is a mixture of bitumen and aggregates, which is very sensitive in the design of flexible pavement. In this study, the Marshall stability of the glass and carbon fiber bituminous concrete was predicted by using Artificial Neural Network (ANN), Support Vector Machine (SVM), Random Forest (RF), and M5P Tree machine learning algorithms. To predict the Marshall stability, nine inputs parameters i.e., Bitumen, Glass and Carbon fibers mixed in 100:0, 75:25, 50:50, 25:75, 0:100 percentage (designated as 100GF:0CF, 75GF:25CF, 50GF:50 CF, 25GF:75CF, 0GF:100CF), Bitumen grade (VG), Fiber length (FL), and Fiber diameter (FD) were utilized from the experimental and literary data. Seven statistical indices i.e., coefficient of correlation (CC), mean absolute error (MAE), root mean squared error (RMSE), relative absolute error (RAE), root relative squared error (RRSE), Scattering index (SI), and BIAS were applied to assess the effectiveness of the developed models. According to the performance evaluation results, Artificial neural network (ANN) was outperforming among other models with CC values as 0.9147 and 0.8648, MAE values as 1.3757 and 1.978, RMSE values as 1.843 and 2.6951, RAE values as 39.88 and 49.31, RRSE values as 40.62 and 50.50, SI values as 0.1379 and 0.2027 and BIAS value as -0.1 290 and -0.2357 in training and testing stage respectively. The Taylor diagram (testing stage) also confirmed that the ANN-based model outperforms the other models. Results of sensitivity analysis showed that the fiber length is the most influential in all nine input parameters whereas the fiber combination of 25GF:75CF was the most effective among all the fiber mixes in Marshall stability.

Parametric optimization of FPSO hull dimensions for Brazil field using sophisticated stability and hydrodynamic calculations

  • Lee, Jonghun;Kim, Byung Chul;Ruy, Won-Sun;Han, Ik Seung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.478-492
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    • 2021
  • In this study, hull dimensions of an FPSO were optimized to maximize its operability at Brazil field. In contrast with the previous works which have used simplified models to evaluate some indicators related to stability and hydrodynamic performances of FPSOs for its own optimal design, we developed a generic hull and compartment modeler and sophisticated stability and hydrodynamic calculation modules. With the aid of the developed tools, the hull optimization was performed with initial dimensions of an FPSO originally designed for west Africa field. The optimization results indicated the relative importance of hydrodynamic performances compared with stability performances for the FPSO hull dimensioning by showing that there were 3 active constraints related to them, which were the natural periods of heave and roll and the maximum pitch angle under 1-year return period waves at full load condition. To the author's knowledge, this study is the first attempt to combine altogether the hull and compartment modeling and full set of stability and hydrodynamic calculations precisely to optimize an FPSO's hull dimensions within 30 min. Also, it is worthwhile to mention that the developed methods are generic enough to be applied to all types of ship-shaped offshore platforms.

Analysis of pile group behaviour to adjacent tunnelling considering ground reinforcement conditions with assessment of stability of superstructures

  • Young-Jin Jeon;Cheol-Ju Lee
    • Geomechanics and Engineering
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    • v.33 no.5
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    • pp.463-475
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    • 2023
  • Tunnel construction activity, conducted mainly in mountains and within urban centres, causes soil settlement, thus requiring the relevant management of slopes and structures as well as evaluations of risk and stability. Accordingly, in this study we performed a three-dimensional finite element analysis to examine the behaviour of piles and pile cap stability when a tunnel passes near the bottom of the foundation of a pile group connected by a pile cap. We examined the results via numerical analysis considering different conditions for reinforcement of the ground between the tunnel and the pile foundation. The numerical analysis assessed the angular distortion of the pile cap, pile settlement, axial force, shear stress, relative displacement, and volume loss due to tunnel excavation, and pile cap stability was evaluated based on Son and Cording's evaluation criterion for damage to adjacent structures. The pile located closest to the tunnel under the condition of no ground reinforcement exhibited pile head settlement approximately 70% greater than that of the pile located farthest from the tunnel under the condition of greatest ground reinforcement. Additionally, pile head settlement was greatest when the largest volume loss occurred, being approximately 18% greater than pile head settlement under the condition having the smallest volume loss. This paper closely examines the main factors influencing the behaviour of a pile group connected by a pile cap for three ground reinforcement conditions and presents an evaluation of pile cap stability.

A comparison study on the estimation of the relative risk for the unemployed rate in small area (소지역의 실업률에 대한 상대위험도의 추정에 관한 비교연구)

  • Park, Jong-Tae
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.2
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    • pp.349-356
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    • 2009
  • In this study, we suggest the estimation method of the relative risk for the unemployment statistics of a small area such as si, gun, gu in Korea. The considered method are the usual pooled estimator, weighted estimator with the inverse of log-variance as weights, and the Jackknife estimator. And we compare with the efficiency of the three estimators by estimating the bias and mean square errors using real data from the 2002 Economically Active Population Survey of Gyeonggi-do. We compute the unemployed rate of male and female in small areas, and then estimate the common relative risk for the unemployed rate between male and female. Also, the stability and reliability of the three estimators for the common relative risk was evaluated using the RB(relative bias) and the RRMSE(relative root mean square error) of these estimators. Finally, the Jackknife estimator turned out to be much more efficient than the other estimators.

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Uncertainty Assessment: Relative versus Absolute Point Dose Measurement for Patient Specific Quality Assurance in EBRT

  • Mahmood, Talat;Ibrahim, Mounir;Aqeel, Muhammad
    • Progress in Medical Physics
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    • v.28 no.3
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    • pp.111-121
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    • 2017
  • Verification of dose distribution is an essential part of ensuring the treatment planning system's (TPS) calculated dose will achieve the desired outcome in radiation therapy. Each measurement have uncertainty associated with it. It is desirable to reduce the measurement uncertainty. A best approach is to reduce the uncertainty associated with each step of the process to keep the total uncertainty under acceptable limits. Point dose patient specific quality assurance (QA) is recommended by American Association of Medical Physicists (AAPM) and European Society for Radiotherapy and Oncology (ESTRO) for all the complex radiation therapy treatment techniques. Relative and absolute point dose measurement methods are used to verify the TPS computed dose. Relative and absolute point dose measurement techniques have a number of steps to measure the point dose which includes chamber cross calibration, electrometer reading, chamber calibration coefficient, beam quality correction factor, reference conditions, influences quantities, machine stability, nominal calibration factor (for relative method) and absolute dose calibration of machine. Keeping these parameters in mind, the estimated relative percentage uncertainty associated with the absolute point dose measurement is 2.1% (k=1). On the other hand, the relative percentage uncertainty associated with the relative point dose verification method is estimated to 1.0% (k=1). To compare both point dose measurement methods, 13 head and neck (H&N) IMRT patients were selected. A point dose for each patient was measured with both methods. The average percentage difference between TPS computed dose and measured absolute relative point dose was 1.4% and 1% respectively. The results of this comparative study show that while choosing the relative or absolute point dose measurement technique, both techniques can produce similar results for H&N IMRT treatment plans. There is no statistically significant difference between both point dose verification methods based upon the t-test for comparing two means.

A FLUOROSCOPIC STUDY ON THE STABILITY OF SKIN REFERENCE POINTS DURING JAW OPENING AND CLOSING MOVEMENT (방사선 투시를 이용한 개폐구 운동에 따른 수직 고경 계측점의 안정성에 관한 연구)

  • Ahn, Hyung-Jun;Kim, Chang-Whe;Kim, Yung-Soo;Kim, Yong-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.37 no.4
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    • pp.516-530
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    • 1999
  • The current clinical technique for occlusal vertical dimension recording is based on marking the skin reference points on the patient's face and measuring between these points using caliper-like device. And it is difficult to achieve reliable measurements by this technique because of movable soft tissue. The purpose of this study is to reveal the stability of skin reference points by comparing the relative movement between extra-oral skin reference points and intra-oral reference points using X-ray fluoroscope. 10 test subjects were divided into 2 groups : Group I (natural dentition) and Group II (denture-wearer whose vertical dimension was lost) and Group III consists of identical test subjects to Group II with their upper denture removed and record base inserted. Attaching the 3 mm diameter steel ball to nose tip, lower lip, chin and to existing denture (or record base), fluoroscopic examination and recording were taken during 2 jaw opening and closing movements. After subsequent digitization using personal computer, 1219 still pictures with 0.1 second interval were made. Using the 2 dimensional graphic software, measurements between reference points were executed. Dividing the entire jaw movement into 3 ranges (total, 1st half opening, 2nd half opening), rate of movement and relative movement between extra-oral and intra-oral reference points were calculated and statistically analyzed. The results of this study are as follows. 1 Within the same experimental group, no statistical difference was found in the stability of skin reference between lower lip point and chin point during total range of jaw opening and closing movement (p>.05) 2. In the first half range of jaw opening, statistical difference was found between Group I (natural dentition) and Group II (denture wearer) (p<.05) Group I has greater skin reference stability than Group II. 3. In the first half range of jaw opening, statistical difference was found between Group I and Group III (record base wearer) (p<.05). Group I has greater skin reference stability than Group III. 4. In the first half range of jaw opening, no statistical difference was found in the stability of skin reference between Group II and Group III (p>.05). 5. In the second half range of jaw opening, no statistical difference was found in the stability of skin reference between any experimental groups (p>.05). 6. In patients with their occlusal vertical dimension lost, employing other measuring references rather than skin is recommended because of low stability.

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Leader-Follower Based Formation Control of Multiple Mobile Robots Using the Measurements of the Follower Robot (추종 로봇의 측정값들을 이용한 다중 이동 로봇의 선도-추종 접근법 기반 군집 제어)

  • Park, Bong Seok
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.5
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    • pp.385-389
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    • 2013
  • This paper proposes the leader-follower based formation control method for multiple mobile robots. The controller is designed using the measurements of the follower robot such as the relative distance and angle between the leader and the follower. This means that the follower robot does not require the information of the leader robot while keeping the desired formation. Therefore, the proposed control method can reduce the communication loss and the cost for hardware. From Lyapunov stability theory, it is shown that all error signals in the closed-loop system are uniformly ultimately bounded. Finally, simulation results demonstrate the effectiveness of the proposed control system.

A Study on the Shear Strength Characteristics of Composited Ground applying RAP Method by Large Direct Shear Test (대형직접전단시험에 의한 RAP 복합지반의 전단강도 특성 연구)

  • Chun, Byung-Sik;Seo, Deok-Dong;Kim, Jong-San
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.82-89
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    • 2004
  • To secure stability and availability of Rammed Aggregate Pier method as the foundation of a structure, the shear strength characteristics according to the area replacement ratio of RAP and the relative density of in-situ ground was studied through soil laboratory tests and large direct shear tests in a model ground. As a result, the internal friction angle tends to increase in proportion to in-situ relative density(Very Loose, Loose, Medium) in composite ground formed by the same area replacement ratio of RAP and also increase in proportion to increasing the area replacement ratio(30, 40, 50%) of RAP in the same ground condition. Furthermore, the comparative analysis between the experimental value and theoretical value of the shear strength is carried out.

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