We report on a comparison of methods based on XRD patterns for calculating crystal size In this case, XRD peaks were extracted from hydroxyapatite obtained from cow, pig, and chicken bones Hydroxyapatite was synthesized through the thermal treatment of natural bones at 950 °C XRD patterns were selected by adjustment of X-Pert software for each method and for calculating the size of the crystals Methods consisted of Scherrer (three models), Monshi-Scherrer, three models of Williamson-Hall (namely the Uniform Deformation Model (UDM), the Uniform Stress Deformation Model (USDM), and the Uniform Deformation Energy Density Model (UDEDM)), Halder-Wanger (H-W), and the Size Strain Plot Method (SSP) These methods have been used and compared together The sizes of crystallites obtained by the XRD patterns in each method for hydroxyapatite from cow, pig, and chicken were 1371, 457, and 196 nm in the Scherrer method when considering all of the available peaks together (straight line model) A new model (straight line passing the origin) gave 60, 60, and 53 nm, which shows much improvement The average model gave 56, 58, and 52 nm, for each of the three approaches, respectively, for cow, pig, and chicken The Monshi-Scherrer method gave 60, 60, and 57 nm Values of 56, 62, and 65 nm were given by the UDM method The values calculated by the USDM method were 60, 62, and 62 nm The values of 62, 62, and 65 nm were given by the UDEDM method for cow, pig, and chicken, respectively Furthermore, the crystal size value was 4 nm for all samples in the H-W method Values were also calculated as 43, 62, and 57 nm in the SSP method for cow, pig, and chicken tandemly According to the comparison of values in each method, the Scherrer method (straight line model) for considering all peaks led to unreasonable values Nevertheless, other values were in the acceptable range, similar to the reported values in the literature Experimental analyses, such as specific surface area by gas adsorption (Brunauer-Emmett-Teller (BET)) and Transmission Electron Microscopy (TEM), were utilized In the final comparison, parameters of accuracy, ease of calculations, having a check point for the researcher, and difference between the obtained values and experimental analysis by BET and TEM were considered The Monshi-Scherrer method provided ease of calculation and a decrease in errors by applying least squares to the linear plot There is a check point for this line that the slope must not be far from one Then, the intercept gives the most accurate crystal size In this study, the setup of values for BET (56, 52, and 49 nm) was also similar to the Monshi-Scherrer method and the use of it in research studies of nanotechnology is advised

https://www.mdpi.com/2079-4991/10/9/1627/pdf

Comparing Methods for Calculating Nano Crystal Size of Natural Hydroxyapatite Using X-Ray Diffraction.

Lubrication-enhanced mechanisms of titanium alloy grinding using lecithin biolubricant

This is an accepted manuscript of an article published by Elsevier in Additive Manufacturing on 02/10/2021, available online: https://doi.org/10.1016/j.addma.2021.102378 
The accepted version of the publication may differ from the final published version.

Fused Deposition Modelling: Current Status, Methodology, Applications and Future Prospects

Biological apatites are characterised by various ionic substitutions within the HAp lattice that are crucial for bone metabolism. The introduction of key role elements within synthetic calcium phosphates (CaP), mainly hydroxyapatite (HAp), can increase osteogenesis and enhance bone regeneration process. The lattice structure of HAp enables cationic and anionic substitutions leading to the enhanced biological performance of synthetic bone graft materials. This review summarises recent and relevant studies on cationic and anionic substitutions in the HAp lattice that are commonly found in the human body. Furthermore, co-substituted HAp obtained from synthetic and biological precursors, along with their influence on the bone regeneration process, has been discussed. Finally, future perspectives for the use of substituted HAp have been presented.

Ionic substituted hydroxyapatite for bone regeneration applications: A review

Fused filament fabrication (FFF), also known as fused deposition modeling (FDM™), is considered one of the most promising additive manufacturing (AM) methods for its versatility, reliability and affordability. First adopted by industries for professional uses such as rapid prototyping, then by the general public in recent years, FFF has gathered itself considerable attention. Nevertheless, despite key advancements in printer technologies and filament materials, the fabrication of robust, performing and functional parts for high-demanding practical applications remains a significant challenge. Due to intrinsic deficiencies, such as the presence of voids and weak layer-to-layer adhesion, FFF-printed parts are plagued by weak and anisotropic mechanical properties in contrast to their conventionally manufactured counterparts. With the increasing demand for designable porous structures in the fields of biomedicine, 4D printing and lightweight cellular composites, understanding the challenges presented by void presence has become more relevant than ever. As existing literature has reviewed the significance of interlayer bonding, this review focuses on documenting recent insights on the formation of voids by its categorization, research method and mechanism. The primary objective is to provide a comprehensive understanding of the two current primary methods of void research—quantitative analysis and imaging. Detailed discussions on the effects of feedstock and printing parameters on void formation are also presented. Lastly, this review discusses gaps in the current research and outlines unaddressed challenges regarding void formation and its relation with the mechanical performance of FFF parts.

N.A.S. Mohd Pu'ad

Papers

Syntheses of hydroxyapatite from natural sources.

A review of gelatin: Properties, sources, process, applications, and commercialisation

Synthesis method of hydroxyapatite: A review

Review on the fabrication of fused deposition modelling (FDM) composite filament for biomedical applications

An updated review on surface functionalisation of titanium and its alloys for implants applications