1.In vitro evaluation of the bond strength between various ceramics and cobalt-chromium alloy fabricated by selective laser sintering.
Eun Jeong BAE ; Hae Young KIM ; Woong Chul KIM ; Ji Hwan KIM
The Journal of Advanced Prosthodontics 2015;7(4):312-316
PURPOSE: This study aimed to present the clinical applicability of restorations fabricated by a new method, by comparing the bond strength of between ceramic powder with different coefficient of thermal expansion and alloys fabricated by Selective laser sintering (SLS). MATERIALS AND METHODS: Fifty Co-Cr alloy specimens (25.0 x 3.0 x 0.5 mm) were prepared by SLS and fired with the ceramic (8.0 x 3.0 x 0.5 mm) (ISO 9693:1999). For comparison, ceramics with different coefficient of thermal expansion were used. The bond strength was measured by three-point bending testing and surfaces were observed with FE-SEM. Results were analyzed with a one-way ANOVA (alpha=.05). RESULTS: The mean values of Duceram Kiss (61.18 +/- 6.86 MPa), Vita VM13 (60.30 +/- 7.14 MPa), Ceramco 3 (58.87 +/- 5.33 MPa), Noritake EX-3 (55.86 +/- 7.53 MPa), and Vintage MP (55.15 +/- 7.53 MPa) were found. No significant difference was observed between the bond strengths of the various metal-ceramics. The surfaces of the specimens possessed minute gaps between the additive manufactured layers. CONCLUSION: All the five powders have bond strengths higher than the required 25 MPa minimum (ISO 9693); therefore, various powders can be applied to metal structures fabricated by SLS.
Alloys*
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Ceramics*
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Fires
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Powders
2.Preliminary results of nutritional intervention by digestive ferments of seed germ powder in combining with available local food on children of the age of combined feeding in Thanh Hoa
Journal of Practical Medicine 2003;439(1):3-4
Malnutrition status of children from 0 to 60 months of age in two agricultural communes in Thanh Hoa province from July 20 to October 20/2000 was investigated. The indicatior of weigh/age shows a rate of 54% of malnutrition. In graphic this rate increases dramatically in the period of 23-34 months of age, the highest is in 25-36 months of age. Digestive ferment Aplaza, a functional food, in combining with local available source of food improved significantly the nutritional state and prevented this malnutritional condition. This is an eligible way of high efficacy to strengthen the awareness and the practice of nutrition, aiding the poor population in rural area
Nutrition Therapy
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Powders
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Child
3.A COMPARATIVE STUDY OF THE PHYSICOCHEMICAL PROPER TIES AND BOND STRENGTH TO METAL BETWEEN THE REGULAR OPAQUE POWDER AND CORE POWDER.
Jang Seop LIM ; Chang Mo CHUNG ; Young Chan JEON
The Journal of Korean Academy of Prosthodontics 1997;35(1):144-164
The purpose of this study were to investigate the chemical composition, mean particle size, linear thermal expansion coefficient and metal-bonding strength of the regular opaque powder and core powder. In this study, 4 types of ceramic powders, namely Duceram Jacket Opaque powder, Duceram Opaque powder, Vita Hi-Ceram powder, Vita VMK Paint On-88 powder were used. Chemical composition was evaluated by EDS(Energy Dispersive X-ray Spectrophotometer, Oxford QX-2000, England), particle size was measured by MALVERN Instruments(MALVERN Instruments SB. OC., U.S.A.) ad linear thermal expansion coefficient was measured by dilatometer(Motoyama, Japan). Bond strength was measured by the Universal tsting machine(Istron Co., Ltd., U.S.A.). The Results were as follows : 1. Through recognition of the relative difference in chemical composition between the core powder and the regular opaque powder, the difference in the proportion of Al2O3 in each type of material is demonstrated ; Duceram Jaket Opaque powder : 30.16%, Duceram Opaque powder : 16.60%, Vita Hi-Ceram : 63.64%, Vita VMK Paint-On 88 : 16.16%. 2. There was no significant difference in the proportion of metal-bonding materials between the core powder and the regular opaque powder. 3. In the regular opaque powder, alkaline materials were incoporated in order to increase the coefficient of thermal expansion. 4. In the particle size analysis, there was no significant difference in mean particle size or in the particle size distribution between the core powder and the regular opaque powder. 5. In the thermal expansion test for temperature range of 25~600degrees C, the regular opaque powder had higher coefficient of thermal expansion than that of core powder. 6. In the 4 point flexural bending test, there was no statistically significant difference in the mean bond strength between the core powder and the opaque powder among the Duceram products.
Ceramics
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Paint
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Particle Size
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Powders
4.Application of design technology for preparing Lingzhu Powder particles based on solvent evaporation method.
Xiao ZHOU ; Liang FENG ; Xiao-Fei ZHANG ; Yan-Jun YANG ; Xiao-Bin JIA ; Jun-Bo ZOU ; Ya-Jun SHI
China Journal of Chinese Materia Medica 2021;46(23):6028-6034
Targeting the deficiencies of Lingzhu Powder, this study introduced the particle design technology to improve its quality. Based on the mechanism of particle design for powder and the characteristics of solvent evaporation method, composite particles consisting of Succinum, Cinnabaris, and artificial Bovis Calculus were prepared. And the powder properties of composite particles and physical mixtures as well as the content uniformity of toxic components were investigated for exploring the technological advantages of particle design in improving the quality of Lingzhu Powder. The results showed that the composite particles prepared using solvent evaporation method and particle design technology were micro-particles, and the stable agglomerate structure could be observed under SEM. Composite particles exhibited better fluidity and compliance in oral intake than physical mixtures. The differences in chromatism, bulk density, and content uniformity of the composite particles were smaller than those of physical mixtures, and the corresponding RSD values \[4.8%, 1.8%, 3.4%(bilirubin), and 0.63%(HgS), respectively\] were smaller. The solvent evaporation combined with particle design technology can be utilized to significantly improve the quality of Lingzhu Powder, which has provided new ideas for the optimization of the quality of traditional Chinese medicinal powder.
Particle Size
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Powders
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Solvents
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Technology
5.The effect of powder A2/powder A3 mixing ratio on color and translucency parameters of dental porcelain.
Wan Sun LEE ; So Yeon KIM ; Ji Hwan KIM ; Woong Chul KIM ; Hae Young KIM
The Journal of Advanced Prosthodontics 2015;7(5):400-405
PURPOSE: The purpose of this study is to mix dental ceramic powder in varying ratios and evaluate the effect of the mixing ratio on color and translucency. MATERIALS AND METHODS: The ceramic powder of shade A3 of the same product was mixed with the shade A2 of three products: IPS e.max Ceram (Ivoclar Vivadent, Schaan, Liechtenstein), Vintage Halo (SHOFU Inc., Kyoto, Japan), and Ceramco 3 (Ceramco-Dentsply, Burlington, NJ, USA) in the following fixed ratios (0 wt%, 25 wt%, 50 wt%, 75 wt%, and 100 wt%) and then fired. A total of 150 specimen of ceramic fired were manufactured in a regular size (W: 8.5 mm, L: 10.5 mm, and H: 1.5 mm). For color and translucency, L*, a*, and b* were measured and Two-way analysis of variance (ANOVA) and One-way analysis of variance (ANOVA) were used for data analysis (alpha=0.05). RESULTS: The higher the mixing ratio was, L*, a*, and b* of IPS e.max Ceram were all increased, and L* of Vintage Halo was reduced and a* and b* were increased. L* and a* of Ceramco3 were reduced and b* of Ceramco3 was increased. Color difference (DeltaE*ab) was increased in all three products as the mixing ratio got higher. Increased mixing ratios resulted in decreased translucency parameter (TP) values for IPS e.max Ceram but increased TP values for Vintage Halo and Ceramco3. CONCLUSION: In this limited study, CIE L*, a*, and b* were influenced by the mixing ratio of the A3 powders and porcelain powder mixtures represented a various color and translucency.
Ceramics
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Dental Porcelain*
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Fires
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Powders
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Statistics as Topic
6.Characterization methods of flowability of traditional Chinese medicine powders.
Yan DU ; Lijie ZHAO ; Yi FENG ; Desheng XU ; Xiaohai LI ; Songtao WANG
China Journal of Chinese Materia Medica 2012;37(5):589-593
OBJECTIVETo characterize the flowability of traditional Chinese medicine (TCM) powders by using appropriate methods.
METHODWith highly flowable direct compression excipients and Chinese traditional medicine powder as raw materials, the flowability of material powders is determined by the Carr method and the Jenike method.
RESULTThe Carr method and the Jenike method for the determination of the flowability of Chinese herb extract powder and direct-pressing excipients have no obvious difference. But the flowability of Chinese herb extract powder is not as good as direct compression excipients.
CONCLUSIONFrom the characterization results of both methods, we can find that the Carr method better reflects the actual flowability of TCM extracts, while the Jenike method can be used for guiding the design of the hopper device.
Medicine, Chinese Traditional ; Particle Size ; Powders ; chemistry
7.A new mathematical equation for the evaluation of the compression behavior of pharmaceutical materials.
Sheng-jun CHEN ; Jia-bi ZHU ; Xiao-le QI
Acta Pharmaceutica Sinica 2012;47(10):1384-1388
A new mathematical equation characterizing the compression of pharmaceutical materials is presented. This equation presumed that the rate of change of the compressible volume of powder with respect to the pressure is proportional to the compressible volume. The new model provided a good fit to several model substances employing non-linear regression techniques. The validity of the model had been verified with experimental results of various pharmaceutical powders according to the Akaikes informatics criterion (AIC) and the sum of squared deviations (SS). The parameter of the new model might reflect quantitatively the fundamental compression behaviors of the powders. It had demonstrated that the proposed model could well predict the compaction characteristics of solid particles like the Kawakita model.
Compressive Strength
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Nonlinear Dynamics
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Powders
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chemistry
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Pressure
8.Correlation of physical properties of herbal extracts and dry granulating process.
Jie LI ; Ruofei DU ; Yi FENG ; Desheng XU ; Kefeng RUAN
China Journal of Chinese Materia Medica 2011;36(12):1606-1609
OBJECTIVETo study the correlation of dry granulation with Chinese extract powder physical properties and dry granulating process parameters to find out the main factors affecting the granulation progress.
METHODThe correlation with the physical properties including angle of repose, compression degree, cohesion, water content, feeding speed, wheel speed and wheel pressure with the yield of grain was investigated by multiple regression analysis.
RESULTThe results showed that compression degree, water content, feeding speed and wheel pressure was positively correlated with the yield of grain in measured range. The angle of repose, cohesion, wheel speed was negative correlated with the yield of grain in measured range.
CONCLUSIONDry granulating was highly influenced by the physical properties of herbal extracts and the parameters of dry granulating process. The greater impact on grain dry method are compression, cohesion and wheel speed.
Drugs, Chinese Herbal ; chemistry ; Powders ; chemistry
9.Efficacy of Aconite Tuber Powder in Patients with Arthralgia and Somatic Pain
Kampo Medicine 2009;60(1):81-85
Heat-treated and detoxified Aconite tuber has many useful properties such as analgesic, diuretic, and cardiotonic effects. Two hundred forty-seven patients were treated with Aconite Tuber powder (1.5 - 8.0g/day) added to Kampo extract granules. The Visual Analog Scale (VAS) was used for the assessment of its pain-relieving effect. One hundred two patients improved dramatically (the pre/post administration VAS ratio was less than 50%), 84 improved (between 51 to 75%), and61did not improved (more than 76%). Three patients(1.2%) showed adverse reactions, such as tongue numbness, squeezing sensation of the bladder, anasarca. These reactions were not serious. This study suggests that Aconite tuber powder can be used more widely, especially for arthralgia and somatic pain with coldness in elderly patients.
Aconitum
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Powders
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Pain
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Cerebellar tuber
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Arthralgia
10.Optimization of dry granulating technique of Qibai Pingfei granule through response surface methodology.
Xue-feng LI ; Yun-xiao LI ; Zhen-qiu XU ; Jin MENG ; Ming YAN ; Rui-ting JIN ; Wei XIAO
China Journal of Chinese Materia Medica 2015;40(15):2975-2978
To determine the optimum process conditions for dry granulating technique of Qibai Pingfei granule, granule excipient type, rolling wheel speed and pressure and feeding speed were studied. Taking shaping rate at a time, moisture absorption and dissolubility as index, the type and amount of granule excipient were determined. In addition, taking shaping rate at a time as index, parameters of rolling wheel speed and pressure and feeding speed were researched through single factor test and response surface methodology. The optimum parameters were as follows: lactose as excipient, dry extract powder to excipient at 1:2, rolling wheel speed and pressure at 10.9 Hz and 6.4 MPa and feeding speed at 7.2 Hz. After validation of three batches pilot-scale production, the optimum processing parameters for dry granulating technique of Qibai Pingfei granule is reasonable and feasible, which can provide reliable basis for production.
Drugs, Chinese Herbal
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Powders
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Technology, Pharmaceutical
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methods