• Title/Summary/Keyword: stability test

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Stability Test for the Cream and Lotion Among the Cosmetic Foundations (기초화장용 제품 중 크림과 로션제의 안정성 평가방법)

  • Cho, Hea-Young;Lee, Suk;Baek, Seung-Hee;Choi, Hoo-Kyun;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
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    • v.33 no.4
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    • pp.293-298
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    • 2003
  • This study was attempted to develop the physicochemical ad morphological stability test methods for the cream and lotion formulations among the cosmetic foundations and to provide the guidance for the stability methods with respect to basic emulsions and creams. With these developed stability test methods, we can evaluate the expired date or life time of the available basic cosmetics, especially basic lotions ad creams. Also, the stability test methods established in this study can be used as a guideline to test physical and morphological stability of cosmetics in the future. Thus, we selected two types of basic cosmetics such as lotions and creams made by four different cosmetic companies ad applied them to the stability test methods depending on the temperature changes such as temperature cycling and freezing-thawing cycling test. After the temperature changes, the conductivity, turbidity, particle size, creaming ratio and pH changes of the creams and lotions were evaluated and morphological changes such as crystal formation, odor, color and feeling of the creams and lotions were also tested. As the results of the stability tests, all the tested creams and lotions except for one lotion were stable. Therefore, it may be concluded that these short-term accelerated stability tests as physical stability test depending on the temperature change study were suitable for the stability testing methods for the basic cosmetics and may be useful for the establishment of the guideline for the stability test of cosmetics.

Performance Evaluation of 100 % RAP Asphalt Mixtures using different types of Rapid-Setting Polymer-Modified Asphalt Emulsion for Spray Injection Application (속경성 바인더 유형에 따른 긴급보수용 스프레이 패칭 상온 재활용 아스팔트 혼합물(RAP)의 성능 평가)

  • Kim, Doo Yeol;Jeon, Ji Seong;Lee, Sang Yum;Rhee, Suk Keun;Kwon, Bong Ju
    • International Journal of Highway Engineering
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    • v.19 no.2
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    • pp.75-85
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    • 2017
  • PURPOSES : The purpose of this study was to determine the optimum mix design of the content of 100 % reclaimed asphalt pavement (RAP) for spray injection application with different binder types. METHODS : Literature review revealed that spray injection method is the one of the efficient and economical methods for repairing a small defective area on an asphalt pavement. The Rapid-Setting Polymer modified asphalt mixtures using two types of rapid setting polymers-asphalt emulsion and a quick setting polymer asphalt emulsion-were subjected to the following tests to determine optimum mix designs and for performance comparison: 1) Marshall stability test, 2) Retained stability test, 3) Wet track abrasion test, and 4) Dynamic stability test. RESULTS and CONCLUSIONS : Type A, B, and C emulsions were tested with different mix designs using RAP aggregates, to compare the performances and determine the optimum mix design. Performance of mixtures with Type A emulsion exceeded that of mixtures with Type B and C emulsion in all aspects. In particular, Type A binder demonstrated the highest performance for WTAT at low temperature. It demonstrated the practicality of using Type A mixture during the cold season. Furthers studies are to be performed to verify the optimum mix design for machine application. Differences in optimum mix designs for machine application and lab application will be corrected through field tests.

Differences in percussion-type measurements of implant stability according to height of healing abutments and measurement angle (임플란트 healing abutment 높이와 타진각도에 따른 타진방식 임플란트 안정성 측정기기의 수치 차이)

  • Park, Yang-Hoon;Leesungbok, Richard;Lee, Suk-Won;Paek, Janghyun;Lee, Jeong-Yol
    • The Journal of Korean Academy of Prosthodontics
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    • v.56 no.4
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    • pp.278-286
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    • 2018
  • Purpose: The purpose of this study was to evaluate the effect of healing abutment height and measurement angle on implant stability when using Periotest and AnyCheck. Materials and methods: 60 implants were placed into artificial bone blocks. After implant insertion, 2, 3, 4 and 5 mm healing abutments were installed on 15 specimens, respectively. Insertion torque value, implant stability test, Periotest value were measured. Insertion torque value was controlled between 45 - 55 Ncm. AnyCheck was used for measuring implant stability test and Periotest M was used for measuring Periotest value. Implant stability test and Periotest value were measured at the angles of 0 and 30 degrees to the horizontal plane. Measured values were analyzed statistically. Results: Insertion torque value had no significant difference among groups. When healing abutment height was higher, implant stability test and Periotest value showed lower stability. Also when measurement angle was decreased, implant stability test and Periotest value showed lower stability. Conclusion: When measuring stability of implants with percussion type devices, measured values should be evaluated considering height of healing abutments and measurement angle.

Effects of Active Craniocervical Movement Training Using a Cognitive Game on Stroke Patients' Balance (인지적 게임을 이용한 능동적 두경부 움직임 훈련이 뇌졸중 환자의 균형에 미치는 영향)

  • Kim, Mi-sun;Choi, Woo-sung;Choi, Jong-Duk
    • Physical Therapy Korea
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    • v.28 no.1
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    • pp.47-52
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    • 2021
  • Background: Compared with normal people, stroke patients have decreased voluntary craniocervical motion, which affects their balance. Objects: This study was conducted in order to examine the effects of active craniocervical movement training using a cognitive game on stroke patient's cervical movement control ability, balance, and functional mobility. Methods: The subject of this study were 29chronic stroke patients who were randomly allocated to either an experimental, cognitive game group (n = 15), or control group (n = 14), to which only neuro-developmental treatment (NDT) was applied. The intervention was conducted 5 times per week, 30 minutes per each time, for a total of 4 weeks. Active angle reproduction test, static stability test, limits of stability test, and Time up and Go (TUG) test, respectively, were carried out in order to evaluate cervical movement control ability, static balance, dynamic balance, and functional mobility. Paired t-test was used in order to compare differences between prior to after the intervention, along with an independent-test in order to compare prior to and after-intervention differences between the two groups. Results: After the craniocervical training with a body-driven cognitive game, the experimental group showed significant differences in flexion, extension, and lateral flexion on the affected side, and rotation on the affected side in the active angle reproduction test. The experimental group indicated significant differences in sway length both with eyes-open and with eyesclosed in the static stability test and in limits of stability test and TUG test. The control group to which NDT was applied had significant differences in flexion in the active angle reproduction test and in limits of stability test and TUG test. Conclusion: The above results mean that craniocervical training using a body-driven cognitive game positively influences stroke patient's cervical movement control ability and as a result their balance and functional mobility.

Further Improvements on Bose's 2D Stability Test

  • Xu, Li;Yamada, Minoru;Lin, Zhiping;Saito, Osami;Anazawa, Yoshihisa
    • International Journal of Control, Automation, and Systems
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    • v.2 no.3
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    • pp.319-332
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    • 2004
  • This paper proposes some further improvements on N.K. Bose's 2D stability test for polynomials with real coefficients by revealing symmetric properties of the polynomials, resultants occurring in the test and by generalizing Sturm's method. The improved test can be fulfilled by a totally algebraic algorithm with a finite number of steps and the computational complexity is largely reduced as it involves only certain real variable polynomials with degrees not exceeding half of their previous complex variable counterparts. Nontrivial examples for 2D polynomials having both numerical and literal coefficients are also shown to illustrate the computational advantage of the proposed method.

Design and Performance Evaluation of DC Generator Control System for Cortrolling Torque of Rotating Shaft (회전축의 정밀 토그 발생용 직류 발전기 제어장치의 설계 및 성능평가에 관한 연구)

  • Kim, G.S.;D.I. Kang;B.D. Ahn
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.6
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    • pp.50-56
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    • 1994
  • A DC generator control system was designed to control the torque of a rotating shaft precisely. The control system is composed of a strain gage type torque cell, a torque cell amplifier, a computer, a D/A converter, a error detector, a DC voltage amplifier and a resistor. The response test under unit step input and the dynamic stability test for the designed control system were carried out. It was confirmed that the settling time from the response test is about 4 s and the error from the dynamic stability test is less than 0.06% of rated output of torque cell. The designed control system may be used to control a DC generator which may be used to apply torque to a rotating shaft.

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Analysis and Stability Test of the Extracts from Astragali Radix, Paeoniae Radix, and Corni Fructus for Toxicity Study (황기, 작약 및 산수유의 독성평가를 위한 성분분석 및 안정성 시험)

  • Tran, Huynh Nguyen Khanh;Nguyen, Van Thu;Han, Kang-Hyun;Moon, Kyoung-Sik;Kim, Jeong Ah;Min, Byung Sun
    • Korean Journal of Pharmacognosy
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    • v.48 no.3
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    • pp.248-254
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    • 2017
  • A simple and reliable reverse phase HPLC method was developed to determine pharmacologically active marker compounds of Astragali Radix, Paeoniae Radix, and Corni Fructus. The stability test of water-extract from three natural medicines were examined for six months. However, no significant changes in the content of the marker compounds of each extract were observed during the investigation.

Stability Test and Analysis of Rubia cordifolia for Carcinogenicity Study (천초근의 발암성 연구를 위한 분석 및 안정성 시험)

  • Kim, Dae-Hyun;Park, Jin-Ho;Kim, Seung-Hyun;Sung, Sang-Hyun
    • Korean Journal of Pharmacognosy
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    • v.43 no.2
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    • pp.147-151
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    • 2012
  • The marker constituent was isolated from Rubia cordifolia as a major compound. Quantitative method for the marker of the natural medicine was developed using HPLC-DAD and using established method the extract of Rubia cordifolia was evaluated. In addition, long term and accelerated stability test in the extract was examined for six months. No significant change in content of the marker constituent of the extract observed during the period of long term test.

Analysis and Stability Test of the Extracts from Dipsaci Radix, Leonuri Herba and Cyperi Rhizoma for Toxicity Study (속단, 익모초 및 향부자의 독성평가를 위한 성분분석 및 안정성 시험)

  • Bae, Yoon-Ho;Huh, Jung-Im;Kwack, Seung-Jun;Seok, Ji-Hyeon;Lee, Jong-Kwon;Kang, Tae-Suk;Woo, Mi-Hee;Choi, Jae-Sue;Min, Byung-Sun
    • Korean Journal of Pharmacognosy
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    • v.43 no.1
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    • pp.79-84
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    • 2012
  • A simple and reliable reverse phase HPLC method was developed to determine pharmacologically active marker compounds of Dipsaci Radix, Leonuri Herba and Cyperi Rhizoma. The stability test of water-extract of three natural medicines were examined for six months. However, no significant change in the content of the marker compounds of each extract observed during the time of investigation.