# Heckel Equation Of The Densification Of Faction

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a) Heckel equation In 1961, Heckel proposed the most widely used equation describing pharmaceutical powder behavior in compaction. It was initially used to study the densification of ceramics and its correlation with pressure. It a first order process where powder pores elimination rate is correlated to the number of pores present. The rate of volume reduction increases as the number of pores decrease. Heckel equation relates the density, pressure and the pore fraction of the powder [16],. This was expressed mathematically as: If the compaction is achieved by plastic deformation and there is no particle rearrangement, heckel plot will give a straight line, but pharmaceutical powder don’t produce straight lines, and this deviation gives …show more content…
The constant a represents the minimum porosity of the powder before compression, while b (the coefficient of compression) is linked to the plasticity of the material. (1 – a) represents the initial relative density of the material. (1/b) corresponds to pressure Pk that is the pressure needed to reduce powder bed by 50%, it is inversely proportional to the ability of powder to deform plastically [7,21,22]. Later studies indicated that this equation could be used to powder form only, and it can be adapted by substituting the initial compaction volume with an initial bulk volume in order to study granules. Another limitation for this equation is that it is applicable to a certain pressure limit, and above this pressure the equation is no longer linear. In general, Kawakita equation is more adapted for high porosity and low pressure [15].
c) Adam’s equation Adam’s equation calculates granules strength from in-die compression data. It considers granules are arranged in parallel columns. Mathematically it is expressed

• ## Fluidization Experiment

The minimum fluidization velocity is used to determine the pressure drop. As mentioned above, when the solid behave like a fluid the bed is at fluidize state. So, minimum fluidization occur when the aluminum oxide start to far apart with each other and behave like a fluid. The experiment with different air flow rate between 2.0 to 20.0 L/min with 1 L/min…

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• ## Alka-Seltzer Co: Two Gases

The answer then is .0298 moles of gas produced. After the reaction, and an incision to release the gas, the mass also had to be identified, which was less than the previous mass, 255.9 grams. The experimental molar mass was 0.0894 grams, found by using the moles of 〖Co〗_2 and the masses. The percent yield came about by dividing the experimental molar mass by the theoretical (44.01grams) to create 20 percent. The percent yield shows how far off the experimental calculations were from the truth.…

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• ## Analysis Of Acetone And Toluene

After starting with 30 mL of an unknown mixture of two solvents, fractional distillation and gas chromatography were used to identify the unknowns as acetone and toluene in a 1 to 2.04 ratio of acetone to toluene. Fractional distillation was first used to separate the unknown mixture into its components based on boiling point. Distillation refers to the method of separating components of a mixture through heating and cooling. Simple distillation, which is especially useful in the separation of less-volatile substances from volatile substances, such as sugar from water, can be used to separate a liquid-liquid mixture if the boiling points of the component liquids differ by more than 40-50°C. A plot of temperature versus volume for a simple…

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• ## Tamoxifen Citrate Case Study Solution

Thus different analytical methods were developed including HPLC technique, using various mobile phases. In the development of analytical method it is extremely important to understand the solubility of an analyte. Tamoxifen citrate is very slightly soluble in water (0.3mg/mL at 20°C; pH 3.0-3.5) with high log P value (6) and is soluble in methanol (50 mg/ml). It also shows pH dependent solubility. (Vamsi,2013) The wavelength selected for analysis was 265nm to reduce baseline noise at absorption maximum (257nm) of Tamoxifen citrate.…

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• ## Crystal Chemistry Lab

However, there is also a limit to this vast increase in volume. Once it has been converted to the high temperature beta phase, since the change in volume is due to the change in tilting angle or the angles between the tetrahedral, the expansion is being constricted and limited to a certain point. As such, ultimately, there will reach…

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• ## Thin Layer Chromatography

Using the equations and the numbers on Table 1 found in the data section, the Rf value for the isolated biphenyl was 0.66, the weight was 0.107 g, and recovery percentage was 35.7%. The pH level of the aqueous solvent was then manipulated from a base (sodium benzoate) back into an acid (benzoic acid), by adding HCl. The Rf value for benzoic acid was 0.115, the weight was 0.092 g and the recovery percentage was 30.7%. Using the equation shown in the data section, the total recovery weight came out to be 0.199 and the total recovery percentage was calculated to be…

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• ## The Results Of Air Permeability, Total Water Absorption, And Mortars

Conclusions This study reports the partial replacement of MK by non-calcined WTS in the production of geopolymer with sodium silicate from RHA. The results showed that the properties of geopolymers binders are highly dependent on the WTS content in the mixture. The binder with WTS increased the setting times, kinetics of temperature test showed low rates of geopolymerization reactions. The workability and the mechanical properties of the geopolymer mortars decreased as the WTS content in the binder increased. The compressive strengths in all curing ages were higher than the minimum required for several types of building components.…

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• ## Lansoprazole Microparticles Lab Report

The diameter of the powder cone was measured and angle of repose was calculated using the following equation [12]. tan Ɵ = h/r where, Ɵ= angle of repose, h= height of cone, r= radius of cone base. Bulk density: Take about 100 gm of lansoprazole microparticles into a dry 250 ml cylinder. The cylinder was filled carefully and level of powder was adjusted without compacting and the unsettled apparent volume (Vo) was noted. Bulk density was calculated, in g/ml [13].…

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• ## Analysis Of Meta-Methyl Nitrobenzoate

Also, their Rf values indicate that the recrystallized solute moved less distance compare to the crude product and started material. This suggests that the product made was Meta-Methyl nitrobenzoate even if it has little different melting point from the literature melting point which is 7880°C. Conclusion/Discussion: During the electrophilic aromatic substitution reaction between methyl benzoate and a nitrating solution of sulfuric and nitric acids, the Meta-Methyl nitrobenzoate product was obtained based on the product melting point range. Percent yield of the crude 56.42% and the percent yield of the recrystallized product was 52.59%. This would indicate that during the recrystallization there was a reduction in the percentage yield of the production.…

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• ## Copper Gta Welding

The increase in ductility is related to the microstructure of the welds at a temperature below 1058 °C. In this temperature range, the amount of liquids among the α-Cu grains is minute, and the composition of the liquids resembles the eutectic of (Cu+Cu2O). Solidification of Cu+Cu2O eutectics at the tip of cracking hinders the propagation of crack between adjacent α-Cu grains, and in some degree leads to the increase of strength. Thus, the strength of the welds increases from 10.3 Mpa at 1058 °C to 12.2 Mpa at 1053 °C. At 1020 °C, which is close to the lower limit of the welds’ S-L range, the ductility of the welds increases to 0.00493, which is very close to the Δε (0.00508) during welding.…

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