Characteristics Of Powder Materials Research Articles

Formulation Development of Medicated Chewing Gum by Direct Compression utilizing the SeDeM Diagram Expert System

The main objective of this study was to prepare and characterize the MCG of Ondan HCl which helps to improve the effectivity of the drug and to investigate the applicability of the SeDeM system for the formulation of MCG. The Ondan HCl was formulated into directly compressed MCG utilizing the SeDeM Diagram Expert System. The MCG was optimized using 32 factorial design. Performance evaluation was carried out by evaluating different parameters. Statistical analysis showed that micromeritic properties were improved after inclusion of appropriate excipient in optimum amount. In-vitro drug release study showed 90.01% drug release whereas ex vivo buccal permeation study exhibited significant drug permeation within 15 min indicating its potential for increasing bioavailability. It was concluded that various characteristics of powder material at pre formulation level can be successfully predicted by SeDeM diagram expert system. The developed medicated chewing gum is more effective than mouth dissolving and conventional tablet formulation.
 Keywords: Ondansetron HCl; Medicated chewing gum; direct compression; SeDeM diagram expert system.

Development of a Mix Design Method for Multiplexed Powder Self-Compacting Concrete Based on the Multiscale Rheological Threshold Theory

The multiscale rheological threshold theory can guide the mix design of self-compacting concrete (SCC) from a trans-scale view. Through the paste thresholds calculated by the mini-slump flow test results, the workability of SCC can be predicted. However, this method shows insufficient prediction accuracy when handling multiplexed powder. In the existing threshold calculation formula, the characteristics of powder materials were described through empirical values, without considering the specific properties of various powders. This paper focuses on the application of the multiscale rheological threshold theory to multiplexed powder SCCs. Through the research on the characteristics of powder materials, especially D50 and Span, the effect of the powder properties on paste thresholds was carried out. The prediction accuracies were confirmed by four sets of self-compacting mixtures at paste and concrete scales and were verified with another set of tests. There are a total of 45 paste and 45 SCC test results with multiplexed powders, including cement, fly ash, and limestone powder. The predicting accuracies are expressed as the relative accuracy ε and the accuracy index ε′, calculated by the comparison of self-compacting zones at paste and SCC scales. The calculation results showed that ε and ε′ of the modified method increased. This modified method can be efficient for the mix design of SCC containing multiplexed powders.

Installation for determination of the elastic and damping characteristics of powder materials with an elastic-dissipative substrate

Development of new composite materials with a given set of properties including a high wear resistance in conditions of abrasive and shock-abrasive wear, hardness, corrosion resistance, damping properties, low cost and manufacturability of the material is an important condition for further progress of the oil and gas, mining, road construction and other industries. A distinctive feature of impact-abrasive wear is the impact interaction of parts resulting in deformation of micro-volumes or chipping, which leads to intensive destruction of the surface layer of the parts. Parts subject to impact-abrasive wear must offer a combination of properties, such as hardness, viscosity, and impact strength, which can be achieved by alloying, for example, nickel, chromium, and other ligatures, as well as by mechanical or chemical-thermal surface hardening. The intensity of impact-abrasive wear is also related to the energy and kinematic parameters of the impact. Data indicate that parts subject to this type of wear should offer a sufficient level of damping properties. However, increase of the damping properties of most materials reduces their strength characteristics, and therefore one of the effective ways to increase the impact and abrasive wear resistance is to use multilayer powder materials, i.e., a «wear-resistant steel-elastic-dissipative substrate». We present the developed installation for studying the elastic and damping characteristics of powder materials with an elastic-dissipative substrate. The design of the installation, the principle of operation, as well as the methods of testing and calculation of the characteristics taken into account when developing and studying the materials exposed to shock loads are presented. The effect of structural and geometric parameters of an elastic-dissipative substrate on the damping coefficient, attenuation decrement, and relative stiffness of the products made of powder materials is considered. It is shown that the use of elastic-dissipative substrates can increase the wear resistance of powder and compact materials to shock-abrasive wear by 5 – 6 times due to the absorption and dispersion of the impact energy acting on them. The developed installation, test procedure, and method for reducing wear can be used in testing composite and multilayer materials for impact and abrasive wear.

Control of Powder Material Automatic Batching System based on PLC

Aiming at the characteristics of powder material, such as easy to dust, easy to leakage, polluting the environment and harmful to human body, an automatic batching system for powder material is designed. The system adopts a quantitative weighing device with buoyancy weighing sensor as the core, feeding with electric vibration feeder and 16 small cups. Simatic S7-1200, the latest generation of Siemens PLC, is used to control the system. 2304HS42A1 motor of Hamderburg Company, Germany, is used to control the movement of the cup on the workbench. The software control scheme of the system is designed. Practice has proved that the system runs stably and has good performance, which is worth popularizing.

Prediction of the effect of taste masking on disintegration behavior, mechanical strength and rheological characteristics of highly water soluble drug (itopride HCl); an application of SeDeM-ODT expert system

Polymeric excipients are commonly applied for taste masking of bitter tasting drugs, to get a palatable dosage form, due to wide spectra of characteristics like safety, availability and cost effectiveness. Taste masking changes nature of powder material and affects rheological characteristics, mechanical strength and disintegration behavior which are mandatory for preparation of a pharmaceutical product meeting the official specifications. Extensive experimentation is carried out to get the optimum rheological characteristics; mechanical strength and disintegration behavior are required for a product. In the present study SeDeM-ODT expert system has been applied for prediction of effect of taste masking on various characteristics of powder material at pre-formulation level. Bitter taste of itopride HCl powder was masked by granulation technique using hydroxy propyl methyl cellulose as taste masking polymer. According to SeDeM-ODT expert system, itopride HCl powder was evaluated for 15 basic parameters, before and after taste masking and results were compared.Taste masking was achieved at 1:3 (drug to HPMC ratio by weight) and panel of healthy male volunteers ranked the composition completely taste masked. Comparison of results before and after taste masking showed that taste masking significantly improved mechanical strength and rheological characteristics and decreased disintegration behavior of powder. From the study it is concluded that the effect of taste masking on rheological characteristics, mechanical strength and disintegration behavior can be successfully predicted by SeDeM-ODT expert system at pre-formulation level avoiding extra experimentation and facilitating the process of formulation development.

Mechanically milled AA6061/(Ti3Al)P MMC reinforced with intermetallics – the structure and properties

The present work investigates the production of aluminium AA6061 matrix composite materials reinforced with Ti3Al particles by powder metallurgy techniques and hot extrusion. The milling process has a big influence on the characteristics of powder materials, changing the spherical morphology of as-received powder during milling process to flattened one due to particle deformation followed by welding and fracturing particles of deformed and hardened enough which allows to receive equiaxial particles morphology again. The investigation shows that so called brittle intermetallic particles yields to plastic deformation as good as ductile aluminium alloy particles. That indicates that in contrary to ceramics particle, the Ti3Al intermetallic powder cannot play a role of the accelerator during mechanical milling. The mechanically milled and extruded composites show finer and better distribution of reinforcement particles what leads to better mechanical properties of obtained products. The hardness increases twice in case of mechanically milled and only 20–25 HV1 for low energy mixed and hot extruded composites. The finer microstructure increase mechanical properties of composites materials. The higher reinforcement content results in higher particles dispersion hardening. Composites reinforced with 15% of Ti3Al reach about 400MPa UTS.

Effect of technological characteristics of powder material on the fluorescence intensity of elemental analytical lines

AbstractThe effect of technological and physical–mechanical characteristics of powder irradiators on the fluorescence intensity of elemental analytical lines was studied experimentally. Investigations were conducted with the use of ferroalloy powders of different grain size, in bulk and pelleted form, at various loads. A dependence of elemental analytical line intensity on the density of powders, both in bulk and pelleted at constant pressure, that was defined by the variation in particle size and surface interaction forces was found. Calculations revealed a correlation between the dependences obtained and the variation of the effective absorption characteristics of irradiators due to different concentrations of the solid irradiation phase, caused by the variations in density and autoadhesive properties of the particles. Variations in pelleting pressure led to similar dependences at other densities of the particle packing, the roughness of the irradiators not exceeding several microns and having a considerable effect on the formation of the irradiation layer. The parameters were found that have the greatest effect on the fluorescence intensity of powder materials. Copyright © 2003 John Wiley & Sons, Ltd.

Al? Be alloys: Multipurpose metallic composite materials

The article is devoted to composite materials created on the basis of the technology of light alloys and developments of the All-Russia Institute of Aircraft Materials concerning beryllium alloys with a high modulus of elasticity. The competitiveness of such composite materials is determined by the high level of the specific strength properties, which exceed, in some cases, the characteristics of powder materials of a similar composition and approach the properties of titanium alloys and steels.

Technological characteristics of powder materials used in hot gas spraying

Technological characteristics of powder materials used in hot gas spraying

Mechanical characteristics of powder materials in a high vacuum

Mechanical characteristics of powder materials in a high vacuum

Influence of some factors on the powder densification process

1. The limiting stressed state of powder materials is described by a linear function known as “Coulomb's flow criterion.” 2. It is demonstrated that, in stress-distribution determinations, powder materials may be analyzed from the viewpoint of the continuity hypothesis. 3. Compared with machine oil, zinc stearate produces a more marked decrease in the strength parameters of a material and gives a greater density gain in pressing at the constant pressure. 4. Additions of more than 0.25 wt.% zinc stearate have no effect on the shear-strength characteristics of powder materials (ϱ and K) and produce no further lowering of compaction pressure. 5. Experiments on the hydrostatic pressing of powders and mixtures established the same character of variation for the shear-strength parameters and density of the materials investigated.