Studying The Effect of Nano-Metakaolin Admixture Material On Mechanical Properties of Oil Well Cement (OWC)

This work aimed to study the effects of incorporate Nano-metakaolin (NMK) as pozzolonic material on some mechanical properties (compressive strength) of Oil Well Cement (OWC). Nano-metakaolin (NMK) was prepared from Kaolin rock brought by thermal activation of kaolin clay at different temperatures (700–800 oC) for 2 h then crushing and ball milled for (40-60) hours. The cement used in this study comprise of Oil Well Cement class G and NMK were incorporate as a partial replacement additive by NMK of (3%, 6% & 10%) by weight of cement with two different average particle sizes (75nm,100nm) and a w/c of 0.44. Several techniques were used to prepare and characterize NMK Particle Size Analyzers (PSA), X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and the Brunauer-Emmett-Teller (BET). The results showed and approved that the NMK was not only work as filler, but also as an activator to consolidate hydration process, through NMK particles react and consumes calcium hydroxide CH crystals to produce more C–S–H, fills pores to increase the strengths, decrease the size of the crystals at the interface zone and transmutes the calcium hydroxide feeble crystals to the C–S–H crystals, and upgrade the interface zone and cement paste domain

Sifat tekan komposit sandwich dengan inti beton cellular diperkuat pin bambu sebagai bahan panel ringan

Cellular lightweight concrete as sandwich composite core has the advantage of its density, with the presence of foam which makes it lighter. However, the presence of foam reduces its strength. Reinforcement with bamboo pins was carried out to increase the compressive strength of the sandwich composite. Bamboo pins connecting the composite skin reinforce the cellular lightweight concrete at an angle of 900, 700,650 to the composite skin. With the addition of bamboo pins, it increases the compressive strength of the sandwich composite in both flat and edge directions

Twin screw granulation : an investigation of the effect of barrel fill level

This paper focuses on investigating the influence of varying barrel fill levels on the mean residence time, granule properties (median size, size distribution, and shape), and tensile strength of tablets. Specific feed load (SFL) (powder feed rate divided by screw speed) and powder feed number (PFN) (i.e., powder mass flow rate divided by the product of screw speed, screw diameter, and the material density in the denominator) were considered as surrogates for the barrel fill level. Two type of powders (lactose and microcrystalline cellulose (MCC)) were granulated separately at varying fill levels at different liquid-to-solid ratios (L/S). It was observed that by controlling the barrel fill level, the granule size, shape, and tablet tensile strength can be maintained at specific L/S. It was also noticed that the mean residence time decreased with increasing fill levels in the case of both lactose and MCC powder. However, it was only found to be related to the change in granule size in case of granulating microcrystalline cellulose at varying fill levels. At very high fill levels, granule size decreased, owing to a limited interaction between MCC powder and liquid at high throughput force and short residence time

Implementation of an online thermal imaging to study the effect of process parameters of roller compactor.

During roller compaction, not only the properties of the primary powder affect the product quality but also the process parameters. Any change in the process parameters during roller compaction will result in changing the properties of the ribbon. In this study, the temperature of the ribbon during production was monitored online using a thermal camera. The information from the thermal camera was used to explain the differences in ribbon properties at varying process parameters. Lactose powder was used as a primary powder, and ribbons were produced at different process parameters. The surface temperature of the ribbon during production was found to increase with increasing both the gap between the two rollers and the roller speed. This was attributed to the screw feeder speed, which increased to feed additional powder as required to adjust to the change in process parameters. Increasing the roller gap resulted in wider ribbons and decreased the percentage of fines in the product, which was a signature of better powder distribution across the roller width. The results were also supported by the uniform temperature distribution recorded across the ribbon width. It was found that increasing the roller speed during roller compaction decreased the width of the ribbon while increasing the percentage of fines in the product. The feeder screw speed was found to have a similar effect as the roller gap

Integrating the physics with data analytics for the hybrid modeling of the granulation process

A hybrid model based on physical and data interpretations to investigate the high shear granulation (HSG) process is proposed. This model integrates three separate component models, namely, a computational fluid dynamics model, a population balance model, and a radial basis function model, through an iterative procedure. The proposed hybrid model is shown to provide the required understanding of the HSG process, and to also accurately predict the properties of the granules. Furthermore, a new fusion model based on integrating fuzzy logic theory and the Dempster-Shafer theory is also developed. The motivation for such a new modeling framework stems from the fact that integrating predictions from models which are elicited using different paradigms can lead to a more robust and accurate topology. As a result, significant improvements in prediction performance have been achieved by applying the proposed framework when compared to single models

Twin screw granulation : effects of properties of primary powders

Lactose and mannitol are some of the most commonly used powders in the pharmaceutical industry. The limited research published so far highlights the effects of process and formulation parameters on the properties of the granules and the tablets produced using these two types of powders separately. However, the comparison of the performance of these two types of powders during twin screw wet granulation has received no attention. The present research is focused on understanding the granulation mechanism of different grades of two pharmaceutical powders with varying properties (i.e., primary particle size, structure, and compressibility). Three grades each of lactose and mannitol were granulated at varying liquid to solid ratios (L/S) and screw speed. It was noticed that primary powder morphology plays an important role in determining the granule size and structure, and tablet tensile strength. It was indicated that the processed powders such as spray-dried and granulated lactose and mannitol can be used in formulation for wet granulation where flowability of active pharmaceutical ingredient (API) is poor

A review of measurement techniques of mechanical properties of the catalyst layer in catalytic converters

A catalyst support is often used to disperse a catalyst material to enhance the contact area for reaction. In catalytic converters, a coating called the catalyst layer contains both the catalyst support and catalytically active material. Given the role of the catalyst layer in catalytic converters, its mechanical strength is of great importance as it determines the service life of catalytic converters. This review paper therefore summarises a number of methods which are currently used in the literature to measure the strength of a catalyst layer. It was identified that the methods applied at present could be divided into two groups. All methods regardless of the group have been successfully used to investigate the effect of a range of formulation and process parameters on the strength of a catalyst layer. In terms of measurement principles, Group 1 methods measure the strength based on mass loss after the layer sample is subjected to a destructive environment of choice. Group 2 methods tend to give more direct measurements on the strength of bonding between particles in a catalyst layer. Therefore, strength data generated by Group 2 methods are more reproducible between different researchers as the results are less dependent on the testing environment. However, methods in both groups still suffer from the fact that they are not designed to separately measure the cohesive and the adhesive strength of a catalyst layer. Two new methods have been recently proposed to solve this problem; with these methods, the cohesive and adhesive strength of a catalyst layer can be measured separately

Modelling the effect of L/S ratio and granule moisture content on the compaction properties in continuous manufacturing

The pharmaceutical field is currently moving towards continuous manufacturing pursuing reduced waste, consistency, and automation. During continuous manufacturing, it is important to understand how both operating conditions and material properties throughout the process affect the final properties of the product to optimise and control production. In this study of a continuous wet granulation line, the liquid to solid ratio (L/S) and drying times were varied to investigate the effect of the final granule moisture content and the liquid to solid ratio on the properties of the granules during tabletting and the final tensile strength of the tablets. Both variables (L/S and granule moisture) affected the tablet tensile strength with the moisture content having a larger impact. Further analysis using a compaction model, showed that the compactability of the granules was largely unaffected by both L/S and moisture content while the compressibility was influenced by these variables, leading to a difference in the final tablet strength and porosity. The granule porosity was linked to the L/S ratio and used instead for the model fitting. The effect of moisture content and granule porosity was added to the model using a 3d plane relationship between the compressibility constant, the moisture content and porosity of the granules. The tablet tensile strength model, considering the effect of moisture and granule porosity, performed well averaging a root mean squared error across the different conditions of 0.17 MPa

Wetting of binary powder mixtures

The wetting process involved when a liquid droplet comes into contact with a mixture of particles is a complex phenomenon which is often understood by reference to Cassie-Baxter theory. However, various authors have applied the Cassie-Baxter theory for the prediction of contact angles on two-component mixtures without success. We hypothesise that the main difficulty in applying the Cassie-Baxter theory to mixtures is that if the particles differ in size, it is possible for the small particles to coat the large particles, so reducing the available surface area of the large particles. This leads to the view that bulk volume fractions are not good estimates of surface fractions of the components within the mixture. We argue that the Cassie-Baxter theory over represents the influence of large particles and that below a certain critical volume fraction they exert no influence. We present a simple geometrical model that relates the critical surface coverage volume fraction to the Sauter mean particle size of the binary mixture components. As a consequence, the wetting behaviour can be determined from the bulk volume fractions and the calculated critical surface coverage volume fraction, by means of a simple geometric model. We show that the simple model describes the five two-components systems reported here and a further four systems reported in the literature, irrespective of whether the larger or small particles are hydrophobic/hydrophilic. With this model, it is possible to predict the wetting behaviour of mixtures of particles that coat each other using very simple characterisation methods, so reducing the development time in the creation of formulations in the pharmaceutical industry

Transparent predictive modelling of the twin screw granulation process using a compensated interval type-2 fuzzy system

In this research, a new systematic modelling framework which uses machine learning for describing the granulation process is presented. First, an interval type-2 fuzzy model is elicited in order to predict the properties of the granules produced by twin screw granulation (TSG) in the pharmaceutical industry. Second, a Gaussian mixture model (GMM) is integrated in the framework in order to characterize the error residuals emanating from the fuzzy model. This is done to refine the model by taking into account uncertainties and/or any other unmodelled behaviour, stochastic or otherwise. All proposed modelling algorithms were validated via a series of Laboratory-scale experiments. The size of the granules produced by TSG was successfully predicted, where most of the predictions fit within a 95% confidence interval