Towards quantification of the role of materials innovation in overall technological development

This article presents a method for quantitatively assessing the role of materials innovation in overall technological development. The method involves classifying the technical changes underlying the overall innovation process first within a set of functional categories and then within each category as a hierarchical array of technical changes. It is specifically found that about 2/3 of the total progress in computation over the past 40 years has been due to materials/process innovations. More speculatively, materials/process innovation contributes at least 20% of the progress in all areas and the relative contribution of materials/process innovation to overall technological progress has grown in the past few decades. © 2012 Wiley Periodicals, Inc. Complexity, 2012     

New global communication process in thermodynamics: impact on quality of published experimental data

Thermodynamic data are a key resource in the search for new relationships between properties of chemical systems that constitutes the basis of the scientific discovery process. In addition, thermodynamic information is critical for development and improvement of all chemical process technologies. Historically, peer-reviewed journals are the major source of this information obtained by experimental measurement or prediction. Technological advances in measurement science have propelled enormous growth in the scale of published thermodynamic data (almost doubling every 10 years). This expansion has created new challenges in data validation at all stages of the data delivery process. Despite the peer-review process, problems in data validation have led, in many instances, to publication of data that are grossly erroneous and, at times, inconsistent with the fundamental laws of nature. This article describes a new global data communication process in thermodynamics and its impact in addressing these challenges as well as in streamlining the delivery of the thermodynamic data from "data producers" to "data users". We believe that the prolific growth of scientific data in numerous and diverse fields outside thermodynamics, together with the demonstrated effectiveness and versatility of the process described in this article, will foster development of such processes in other scientific fields.     

Round‐robin test for the measurement of layer thickness of multilayer films by secondary ion mass spectrometry depth profiling

An international round‐robin test (RRT) was performed to investigate a method to determine the interface location and the layer thickness of multilayer films by secondary ion mass spectrometry (SIMS) depth profiling as a preliminary study to develop a new work item proposal in ISO/TC‐201. Two types of reference materials were used in this RRT. A SiGe alloy (Si_52.4Ge_47.6) reference film was used to determine the relative sensitivity factors of Si and Ge. A Si/Ge multilayer reference film was used to determine the relative sputtering rates of the Si and Ge layers. The layer thicknesses were measured from the interfaces determined by a 50 atomic percent definition. Seven laboratories from 5 countries participated in this international RRT. The RRT reference expanded uncertainties for Si and Ge layers in a Si/Ge multilayer with similar thicknesses as the reference film were 0.76 and 1.17 nm, respectively. However, those in a thinner Si/Ge multilayer film were slightly larger at 1.04 and 1.59 nm, respectively. Most of the thickness ratios in the 2 Si/Ge multilayer films were consistent with the RRT reference value within their expanded uncertainties.     

Final report on VAMAS round‐robin study to evaluate a correction method for saturation effects in DSIMS

A Versailles Project on Advanced Materials and Standards round robin test (RRT) has been conducted to evaluate the linearity of the instrumental intensity scale and correction method using an approximation intermediate extended dead time model with parameters derived from two different isotope depth profiles. Nine organizations in five countries participated. An arsenic‐implanted silicon wafer and a film of BN diffused into a Si wafer were supplied by the National Institute of Advanced Industrial Science and Technology along with instructions for the RRT. The instruments used to analyze ¹⁰³(AsSi)^? and ¹⁰⁵(AsSi)^? from arsenic‐implanted samples were five quadrupole‐type SIMS and four magnetic‐sector type SIMS. The instruments used to analyze ¹⁰B⁺ and ¹¹B⁺ from the BN‐diffused samples were three quadrupole‐type SIMS, four magnetic‐sector type SIMS, and one time‐of‐flight type SIMS. We validated the usefulness of the approximation intermediate extended dead time model to correct saturated intensities for all SIMS in this RRT. The optimum extension parameter ρ tends to be affected by the ratio of the maximum reliable intensity to the maximum intensity in raw profiles. From the ratio, ρ may be predicted when the intensity reaches full saturation. On the other hand, ρ is also affected by lateral non‐uniformity of intensity. In practice, because the maximum intensity does not reach full saturation and the intensity is not laterally uniform, ρ is likely to be smaller than its predicted value. Copyright © 2015 John Wiley & Sons, Ltd.     

Structure and aggregation of a helix-forming polymer

We have studied the competition between helix formation and aggregation for a simple polymer model. We present simulation results for a system of two such polymers, examining the potential of mean force, the balance between intermolecular and intramolecular interactions, and the promotion or disruption of secondary structure brought on by the proximity of the two molecules. In particular, we demonstrate that proximity between two such molecules can stabilize secondary structure. However, for this model, observed secondary structure is not stable enough to prevent collapse of the system into an unstructured globule.     

Arithmetic,Zeros, and Nodal Domains on the Sphere

We obtain lower bounds for the number of nodal domains of Hecke eigenfunctions on the sphere. Assuming the generalized Lindelöf hypothesis we prove that the number of nodal domains of any Hecke eigenfunction grows with the eigenvalue of the Laplacian. By a very different method, we show unconditionally that the average number of nodal domains of degree l Hecke eigenfunctions grows significantly faster than the uniform growth obtained under Lindelöf.     

Study of structural and electronic transport properties of Ce-doped LaMnO3

The structural and electronic transport properties of La_1−x Ce _x MnO₃ (x=0.0–1.0) have been studied. All the samples exhibit orthorhombic crystal symmetry and the unit cell volume decreases with Ce doping. They also make a metal-insulator transition (MIT) and transition temperature increases with increase in Ce concentration up to 50% doping. The system La_0.5Ce_0.5MnO₃ also exhibits MIT instead of charge-ordered state as observed in the hole doped systems of the same composition.