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Crack formation and its possible prevention or remedy is an important branch of material science, closely related to study of granular materials and soft matter physics. This work reports a study on cracking behaviour in composites of bentonite and Laponite® in varying proportions. Both components are clays of the montmorillonite group. Our experiments demonstrate that for the particular composition - Laponite® : bentonite ∽ 1:1, cracks are totally absent. If either component exceeds the other, cracks develop. This is demonstrated over a range of film thickness. Scanning Electron Microscope (SEM) images of the films at different compositions indicate that at this particular ratio, the much smaller particles of Laponite®, pack into the spaces between the bentonite platelets perfectly, to form a defect-free smooth film.

Background: Femur being the strongest and longest bone of the skeleton plays a crucial role in maintaining the usual anatomy of the hip joint. The neck–shaft angle (NSA) contributes greatly to the daily activity of the hip joint and therefore is of considerable importance in planning a proper surgery. Knowledge of the usual range of NSA is, therefore, imperative in the proper treatment of patients who present with disease of the hip related to the NSA. The objective of the present study was to estimate the minimum, maximum, mean, median, and range of NSA and to determine the difference(s) between the right and left sides of dry adult femora in the Gangetic region of West Bengal. Methodology: The present study was conducted on 281 dry adult femora (144 on the left and 137 on the right sides). The femora were selected according to the inclusion and exclusion criteria. Measurements of NSA were based on the standard method. Results: The mean NSA of the total sample size was 124.12° ± 6.231°. The means for the left and right NSAs were 123.33° ± 6.47° and 124.91° ± 5.885°, respectively. The mean difference between the right and left femora was statistically significant. There was also a high degree of positive correlation between the NSAs of the left and right sides. Conclusion: This study establishes baseline data for the NSA of the Gangetic region of West Bengal, India. This will be helpful for orthopedic surgeons and implant makers to properly design and treat patients with problems of the NSA.