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Pharmaceutical study on the Compressed Tablets. Hardness, Friability, Disintegration time and Coefficient of Variance of Compressed tablets (정제류(錠劑類)의 제제학적(製劑學的) 연구(硏究) -경도(硬度), 마손도(磨損度), 붕해시간(崩解時間) 및 변동계수(變動係數)에 대(對)하여)

  • Kim, Soo-Uck;Suh, Sung-Hun;Lee, Hyun-U
    • Journal of Pharmaceutical Investigation
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    • v.2 no.2
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    • pp.18-33
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    • 1972
  • Pharmaceutical Study on the Compressed tablets. Hardness, Friability, Disintegration time and Coefficient of Variance of Compressed tablets. Soo Uck Kim, Sung Hoon seo and Hyun Woo Lee (Department of Pharmaceutics, College of Pharmacy, Kyung Hee University) In order to know Hardness, Friability, Disintegration time and Coefficient of variance of the pharmaceutical tablets the 135 tablets sampled from market were tested in the paper. The samples tested in this paper were as follows: Antipyretics and Analgetics 41 Stomach and Digestives 22 Antituberculars 19 Vitamins 12 Sulfa drugs 9 Others (Antihistaminics etc) 32 Total 135 The results of the investigation are shown in table 1-8, Fig 1-Fig 6. Mean values of Hardness, Friability, Disintegration time and Coefficient of variance in each pharmaceutical preparation are as follows. Antipyretics and Analgetics : Hardness(kg) = 5.83 Antipyretics and Analgetics : Friabil.(%) = 0.82 Antipyretics and Analgetics : Disint.t.(min) = 5.28' Antipyretics and Analgetics : Coeff. of V.(%) = 2.90 Stomach and Digestives : Hardness(kg) = 4.11 Stomach and Digestives : Friabil.(%) = 0.71 Stomach and Digestives : Disint.t.(min) = 3.43' Stomach and Digestives : Coeff. of V.(%) = 2.76 Antituberculars : Hardness(kg) = 4.78 Antituberculars : Friabil.(%) = 0.52 Antituberculars : Disint.t.(min) = 4.32' Antituberculars : Coeff. of V.(%) = 2.99 Vitamins : Hardness(kg) = 1.60 Vitamins : Friabil.(%) = 0.43 Vitamins : Disint.t.(min) = 4.10' Vitamins : Coeff. of V.(%) = 3.19 Sulfa drugs : Hardness(kg) = 4.77 Sulfa drugs : Friabil.(%) = 0.37 Sulfa drugs : Disint.t.(min) = 3.10' Sulfa drugs : Coeff. of V.(%) = 2.09 Others : Hardness(kg) = 2.40 Others : Friabil.(%) = 0.66 Others : Disint.t.(min) = 2.19' Others : Coeff. of V.(%) = 3.10 The following summeries might be shown; 1. Ranges of Hardness, Friability, Disintegration time and Coefficient of variance are respectively 1.6 to 5.38 kg, 0.37 to 0.82%, 2 minut 19 second to 5 minut 28 second and 2.09 to 3.10%. 2. According to the results, it could be indicated that higher Hardness shows lower Friability. 3. Against the general conception between Hardness and Disintegration time, higher Hardness shows lower Disintegration time. 4. It seems that higher mean weight shows lowcr Coefficient variance.

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HARDNESS CHANGE OF LIGHT-ACTIVATED GLASS IONMER CEMENT WITH THICKNESS AND TIME (광경화형 글래스아이오노머 시멘트의 두께 및 시간경과에 따른 경도의 변화)

  • Lee, Kyoung-Jin;Oh, Won-Mann;Kim, Sun-Hun
    • Restorative Dentistry and Endodontics
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    • v.20 no.1
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    • pp.303-315
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    • 1995
  • An adequate and homogeneous cure of light-activated restroative material is very important for improvement of marginal adaptation and prevention of marginal leakage, secondary caries and pulpal irritation as well as expressing natural physical property of that material. The purpose of this study was to evaluate the change of surface hardness and cure uniformity of light-activated glass ionomer cements. Restorative(Fuji II LC, Vitremer) and lining(Baseline VLC, Vitrebond) light-activated glass ionomer cements were investigated for this study. The surface hardness of the top and bottom surfaces and cure uniformity of each 1mm, 1.5mm, 2mm, 2.5mm & 3mm in the thickness of specimen were measured immediately, at 1 hour, 24 hours and 1 week after light activation. The surface hardness change and cure uniformity of all the specimens were measured by Knoop hardness tester. The results were as follows. 1. The surface hardness of top and bottom surfaces in all groups increased with time(p<0.01). 2. Both top and bottom surfaces hardness of Vitrebond group measured immediately after light-activation were significantly lower than those of the other groups(p<0.01). 3. The surface hardness of top and bottom surfaces of restorative light -activated glass ionomer cements was higher than those of lining materials at 1 week(p<0.10). 4. Surface hardness of Vitremer group decreased as the specimen thickness increased, except top and bottom surfaces hardness of the specimen at 1 week(p<0.01). There was no significant difference in the surface hardness of Fuji II LC with changes in the thickness except bottom surface hardness of specimen at 24 hours and 1 week (p>0.05). 5. Surface hardness of Vitrebond group significantly decreased as the specimen thickness increased(p<0.01). There was no significant difference in the surface hardness of Baseline VLC group with changes in the thickness except bottom surface hardness of specimen measured immediately after light -activation(p>0.05). 6. The hardness ratio of top against bottom surface in all groups decreased with time(p<0.05). 7. There was no significant difference in the hardness ratio of top against bottom surface with changes of the thickness except Vitrebond group, 24 hours and 1 week of Vitremer group and 1 week of Baseline VLC group (p>0.05). These results suggest that surface hardness of restorative ligh-activated glass ionomer cements were highter than those of lining light-activated materials. In all groups, the surface hardness and cure uniformity continuously increased with time.

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Effects of Flame Peeling Characteristics on the Hardness of the Chestnut Shells (밤 외피 경도가 화염박피 특성에 미치는 영향)

  • 김종훈;박재복;최창현;김재민
    • Journal of Biosystems Engineering
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    • v.23 no.4
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    • pp.351-358
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    • 1998
  • It was intended to investigate that how hardness of chestnut shell affects the flame peeling characteristics of Korean Chestnut. Effects of the hardness on the flame peeling characteristics need to be found to establish the optimum drying conditions for chestnut of various cultivars, sizes and harvested years. The equation based on the hardness of the chestnut shells was developed. It was found that the flame peeling characteristics of the corresponding to the various drying conditions did not differ significantly to the groups with the same hardness. The flame peeling characteristics of the chestnut with the same hardness were not influenced by cultivars, size, and harvested year, The peeling ratio and the heating depth were increased by decrease of the hardness of the chestnut shells. On the other hand, the peeling ratio and the heating depth were increased as the flame temperature was increased with the same hardness. When the heating depth was limited to 2.1 mm regarding the process characteristics and the damage ratio, the proper hardness and peeling ratio of chestnut shells were 1,369.8 g/$\textrm{mm}^2$ and 83.9%, respectively, at the flame temperature of $700^{\circ}C$. And also 1,517.7 g/$\textrm{mm}^2$ and 80.7% at 75$0^{\circ}C$.

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A Study on the Measuring Accuracy of Ultrasonic Hardness Tester (초음파 경도계의 측정정도에 관한 연구)

  • Han, Eung-Kyo;Yoon, Jong-Hak;Kim, Jae-Yeor
    • Journal of the Korean Society for Precision Engineering
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    • v.4 no.1
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    • pp.65-73
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    • 1987
  • In recent days, the application of ultrasonics has been increased in the field of engineering and medicine. The ultrasonic hardness tester to apply the principle of contact compliance method is entirely different from hardness tester in the past and in the practical use, the more pre- cisive measurement is required because it has a slight change of hardness value due to the difference of resonance frequency. Therefore, in this study, as one type of applicative transducers which can detect the optimum pressure load, ring type load cell was used in the measurement of ultrasonic hardness. From experimental results, it was compared ultrasonic hardness testing method with the other hardness testing methods. Also, the measurement error of ultrasonic hardness tester could be measured within .+-. 0.5 HRC F.S. in the case of 3.0Kg pressure load.

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Effect of Triacetin and Activated Carbon on the Hardness of Cellulose Acetate Filter containing Activated Carbon (활성탄과 가소제가 탄소복합필터의 경도에 미치는 영향)

  • 신창호;김종열;김정열;김영호;이영택
    • Journal of the Korean Society of Tobacco Science
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    • v.22 no.2
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    • pp.157-163
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    • 2000
  • Filter hardness is important to filter and cigarette manufactures because it is directly related to the ability of a plugmaker during making filter and to the acceptability of the filter by the consumer. In general, glycerol triacetate(Triacetin, TA) is the currently used common plasticizer in making filters from cellulose acetate tow and the effect of triacetin on hardness of filter which is made of mono cellulose acetate tow was well known. But unfortunately, the effect of triacetin on the hardness of cellulose acetate filter containing ativated carbon(carbon filter) was not reported so far. In this study, we manufactured filters with various carbon content at different triacetin concentrations and then analyzed the filter hardness and pressure drop. Filter hardness was directly increased with triacetin concentration but pressure drop was not affected and the effect of carbon content on filter hardness was smaller than that of triacetin concentration. However, pressure drop was directly increased with carbon content.

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Hardness Estimation of Compressor Journal for a Use of Instrumented Indentation Techniques (계장화 압입시험법을 이용한 차량용 컴프레서 저널 경도 평가)

  • Kwak, Sung-Jong;Jin, Ji-Won;Kim, Tae-Seong;Noh, Ki-Han;Kang, Ki-Weon
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.21 no.3
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    • pp.376-381
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    • 2012
  • This paper deals with application of instrumented indentation technique for quality inspection methodology for automobile component. For this, the instrumented indentation tests were performed the normal and cracked compressor journal, which is made from spheroidal graphite cast iron and utilized in air-conditioning system. And the Brinell hardness was estimated using the unloading slope and maximum indentation force. With the aid of Normal distribution, this Brinell hardness was statistically compared and analyzed with hardness measured by indentation hardness tests. Also, application possibility of reliability-based quality inspection criteria for compressor journal was evaluated through the probabilistic analysis for the Brinell hardness estimated by instrumented indentation technique.

A Study on the Vegetation Properties of Slope Areas according to the Soil Hardness (토양경도에 따른 비탈면 식생 특성에 관한 연구)

  • Kil, Sung-Ho;Lee, Dong-Kun;Ahn, Tong Mahn;Koo, Meehyun;Kim, Te Yon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.5
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    • pp.115-127
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    • 2012
  • This study was conducted on the measurement of soil hardness through a hardness testing machine in slopes of natural environments and artificial environments which is generally known as slope revegetation. The soil hardness as one of physicochemical soil properties is significantly associated with plant growth. Although another studies related to the slope revegetation was focused on herbaceous plants, studies related to soil properties for arbor appearance is lack. It was focused on the correlation analysis between the soil hardness and the plant appearance. the results were as follows : The higher the soil hardness is, the less the appearance of plants is as a result of survey. Species appearing in the high levels of the soil hardness represented mugwort and grass. The levels of the soil hardness in the slope of natural environments was good environmental conditions with various plants in the range of 6 to 12mm. The levels of the soil hardness in the slope revegetation was in the 6.88-30mm range. The soil hardness below 21mm showed a variety of plants with arbors and herbaceous plants, whereas it above 21mm represented a monotonous style of plant structure including Artemisia princeps, Lolium perenne, Poa pratensis L and Setaria viridis. The result of the correlation analysis between the soil hardness and the plant appearance was negatively correlated with justifiable significance levels. The result of a logistic regression analysis for tree appearance was statistically proved when the numerical value of the soil hardness is lower.

AN EXPERIMENTAL STUDY ON HARDNESS IN VISIBLE LIGHT-CURED COMPOSITE RESIN AT VARYING DEPTH (가시광선(可視光線) 복합(復合)레진의 심부경도(深部硬度) 측정(測定)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Myoung, Jae-Keun;Lee, Myoung-Jong
    • Restorative Dentistry and Endodontics
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    • v.11 no.1
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    • pp.43-52
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    • 1985
  • The purpose of this study was to measure the Micro-Knoop Hardness of three commercial visible light-cured composite resins (Plurafil-super, He1iosit and Durafi) according to the difference of depth and shade. Specimens of the resin were prepapared in plastic tubes 5mm in diameter with height of 5mm, and the tubes were put into the columned holes in stone molds. The molds were exposed to the visible light through the hole 5mm in diameter in metal plate. Specimens were sectioned (longitudinally) with disk. Knoop Hardness measurements were made at the depth of surface, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0mm from the surface to the deep portion. Knoop Hardness numbers were taken on each depth under 20gm load for 10 seconds with Shimadzu Tester. The following results were: 1. The highest hardness value was measured at 0.5mm depth. Then the deeper the depth, the lesser the hardness was observed. 2. The value of hardness was directly propotional to the time of exposure to the light. 3. The hardness of light shade resin was higher than the that of the dark shade. 4. The pattern of hardness change at varying depth is similar to all the experimental materials with no relation to the shade nor exposure time.

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An Effect Analysis of Rearfoot Movement and Impact force by Different Design of Running Shoes Hardness (런닝화의 경도 차이가 후족 제어 및 충격력에 미치는 영향 분석)

  • Lee Dong-Choon;Lee Woo-Chang
    • Proceedings of the Society of Korea Industrial and System Engineering Conference
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    • pp.291-296
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    • 2002
  • The midsole hardness of athletic footwear affects capability of absorbing impact shock and controls rearfoot movement during running and walking. The prior studies were focused on examining the proper hardness of footwear for rearfoot movement or to finding effective hardness for absorbing impact shock. The displacements of maximal Achilles tendon angle described a amount of pronation motion is decreased when medial hardness of midsole is large more than lateral. Increasing hardness of footwear midsole are effected to reduce maximum and intial pronation angle, but declined the ability of impact shock during heelstrike. For determination of effectiveness hardness of midsole, therefore, the study that makes a compromise between rearfoot movement and absorbing impact during footstrike must be performed. The purpose of this study is to examine quantitative values of rearfoot control and absorbing impact shock with different hardness of medial and lateral midsole on heel portion. The results are useful to define biomechanical hardness of midsole for developing running shoes. As variable for impact shock, accelerations onto shank and knee are measured during 4 running speeds (5, 7, 9, 11km/h). Also, maximum and $10\%$ pronation angle (Achilles tendon angle) were measured using high-speed camera.

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The Change of Sliding wear properties of Carbon Steel against several hardened steels (미끄럼 접촉을 하는 탄소강의 경도차 조합에 따른 마모특성변화 연구)

  • Lee Han Yeong;Kim Geun Yeong
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.85-90
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    • 2003
  • Although wear resistance of material improves with increasing its hardness, it is known that the wear resistance of steel is varied with hardness of counter material. In this context, wear properties of steel must be depended on the difference of hardness between the testpiece and the counter material. In this study, using the pin-on-disc type wear machine, annealed carbon steels were tested against ahoy tool steels with various levels of hardness. Then the changes of wear properties of carbon steel according to the hardness of counter material were investigated and the morphology of worn surface after test were evaluated. The results indicate that if there are no remarkable difference of hardness between them, wear resistance of carbon steel in running-in wear decreases with increasing the hardness of counter material. However, its wear properties at the range of high sliding speed have no relation with hardness of counter material. It is clear that wear properties is influenced by the formation of oxide of steel on their worn surface during wear.

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