The incremental hole-drilling method for measuring non-uniform residual stresses gives stress results that are very sensitive to errors in the measured data. The resulting stress errors can easily become large enough to compromise seriously the usefulness of the calculated stress results. This paper describes a straightforward method for calculating the stress range that has a specified probability of containing the actual residual stresses. Knowledge of this range allows informed interpretations of the stress results to be made. The four measurement error sources considered are: strain errors, hole depth errors, uniform hole diameter errors, and material constant errors. Both the Integral and Power Series stress calculation methods are investigated, and their different responses to measurement errors are described.

Hard and straight: Diamond is the hardest material known, yet polyyne—a molecular rod comprised of CC units—resists longitudinal compression with a Young's Modulus 40 times larger than diamond, whereas [n]staffanes have a Young's Modulus close to that of diamond. Mechanical engineering provides the connection between the point at which a rod buckles under longitudinal load and its cross‐sectional area.

Negative feedback: Auxetic materials are materials that, counterintuitively, become thicker when stretched and thinner when compressed (negative Poisson's ratio). Quantum mechanical computations were used to identify poly[n]prismanes (n=3–6), the first nanomolecular systems that manifest auxetic behavior at the molecular level. The magnitude of the negative Poisson's ratio in these prismanes ranges from 7 to 15 %.

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