Statistics and Measurements

For more than 50 years, the Statistical Engineering Division (SED) has been instrumental in the success of a broad spectrum of metrology projects at NBS/NIST. This paper highlights fundamental contributions of NBS/NIST statisticians to statistics and to measurement science and technology. Published methods developed by SED staff, especially during the early years, endure as cornerstones of statistics not only in metrology and standards applications, but as data-analytic resources used across all disciplines. The history of statistics at NBS/NIST began with the formation of what is now the SED. Examples from the first five decades of the SED illustrate the critical role of the division in the successful resolution of a few of the highly visible, and sometimes controversial, statistical studies of national importance. A review of the history of major early publications of the division on statistical methods, design of experiments, and error analysis and uncertainty is followed by a survey of several thematic areas. The accompanying examples illustrate the importance of SED in the history of statistics, measurements and standards: calibration and measurement assurance, interlaboratory tests, development of measurement methods, Standard Reference Materials, statistical computing, and dissemination of measurement technology. A brief look forward sketches the expanding opportunity and demand for SED statisticians created by current trends in research and development at NIST.     

Accelerating Scientific Discovery Through Computation and Visualization

The rate of scientific discovery can be accelerated through computation and visualization. This acceleration results from the synergy of expertise, computing tools, and hardware for enabling high-performance computation, information science, and visualization that is provided by a team of computation and visualization scientists collaborating in a peer-to-peer effort with the research scientists.In the context of this discussion, high performance refers to capabilities beyond the current state of the art in desktop computing. To be effective in this arena, a team comprising a critical mass of talent, parallel computing techniques, visualization algorithms, advanced visualization hardware, and a recurring investment is required to stay beyond the desktop capabilities.This article describes, through examples, how the Scientific Applications and Visualization Group (SAVG) at NIST has utilized high performance parallel computing and visualization to accelerate condensate modeling, (2) fluid flow in porous materials and in other complex geometries, (3) flows in suspensions, (4) x-ray absorption, (5) dielectric breakdown modeling, and (6) dendritic growth in alloys.     

Contributions of NIST/NBS Researchers to the Crystallography of Construction Materials

For more than 100 years, the primary theme underlying the NBS/NIST staff contribution to the crystallography of building materials has been the development of an improved understanding of concrete materials performance. Over that time period, portland cement concrete has become one of the most important of our construction materials for roads, buildings, and other large municipal structures. At the beginning of the 20th century our understanding of portland cement composition, performance, use in concrete, and how the concrete performs in harsh environments was lacking. The efforts of NIST have served to advance construction materials science and technology through the combined efforts of experimental, field study, and theoretical computational materials science. One major achievement in the late 1920s, derived from studies on phase equilibria in cement clinker, allows calculation of potential cement clinker composition. Known as the Bogue calculation, this continues to be an essential tool in cement plant process control to this day. Additionally, contributions of NIST scientists to our knowledge of the chemistry and nature of cement hydration products have been crucial in our understanding of cement hydration and concrete durability. Today, computational materials science is a rapidly developing discipline, and NIST is developing tools incorporating predictive models aided by empirical studies. Examples include a computer-integrated knowledge system for prediction and optimization of performance and life-cycle cost of high performance concrete and the Virtual Cement and Concrete Testing Laboratory. Understanding the relationships between material and performance properties has not been confined only to portland cements. One of the longest running experiments at NIST, the stone test wall, has stood for over 50 years as one of the world’s largest single collections of building stone, and is invaluable for studying weathering effects associated with stone mineralogy and texture. Standards development has also been promoted through participation on ASTM subcommittees on stone, cement, and concrete. The Cement and Concrete Reference Laboratory, established in 1929, continues to provide testing and training for outside laboratories and maintains a historical record of test data on construction materials.     

Mathematics and Measurement

In this paper we describe the role that mathematics plays in measurement science at NIST. We first survey the history behind NIST’s current work in this area, starting with the NBS Math Tables project of the 1930s. We then provide examples of more recent efforts in the application of mathematics to measurement science, including the solution of ill-posed inverse problems, characterization of the accuracy of software for micromagnetic modeling, and in the development and dissemination of mathematical reference data. Finally, we comment on emerging issues in measurement science to which mathematicians will devote their energies in coming years.     

Review of Instrumented Indentation

Instrumented indentation, also known as depth-sensing indentation or nanoindentation, is increasingly being used to probe the mechanical response of materials from metals and ceramics to polymeric and biological materials. The additional levels of control, sensitivity, and data acquisition offered by instrumented indentation systems have resulted in numerous advances in materials science, particularly regarding fundamental mechanisms of mechanical behavior at micrometer and even sub-micrometer length scales. Continued improvements of instrumented indentation testing towards absolute quantification of a wide range of material properties and behavior will require advances in instrument calibration, measurement protocols, and analysis tools and techniques. In this paper, an overview of instrumented indentation is given with regard to current instrument technology and analysis methods. Research efforts at the National Institute of Standards and Technology (NIST) aimed at improving the related measurement science are discussed.     

The Fundamental Neutron Physics Facilities at NIST

The program in fundamental neutron physics at the National Institute of Standards and Technology (NIST) began nearly two decades ago. The Neutron Interactions and Dosimetry Group currently maintains four neutron beam lines dedicated to studies of fundamental neutron interactions. The neutrons are provided by the NIST Center for Neutron Research, a national user facility for studies that include condensed matter physics, materials science, nuclear chemistry, and biological science. The beam lines for fundamental physics experiments include a high-intensity polychromatic beam, a 0.496 nm monochromatic beam, a 0.89 nm monochromatic beam, and a neutron interferometer and optics facility. This paper discusses some of the parameters of the beam lines along with brief presentations of some of the experiments performed at the facilities.     

RILEM and the National Institute of Standards and Technology (NIST) over the past 50 years

There has been a long partnership in the materials science of building materials between the National Institute of Standards and Technology (NIST) in the United States and the International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM). This paper discusses on the technical contributions NIST has made to RILEM, focusing on the articles published in Materials and Structures, whose 50-year anniversary is being celebrated in this issue. Since 1968, NIST has had a name change and a building materials division was formed, merged, and renamed since the 1970s, while RILEM has stayed constant in its name and organization, although its technical committee structure is purposely fluid. Many NIST personnel have contributed to the partnership between RILEM and NIST in more than one material type. This overview briefly covers these areas.     

Standards for bullets and casings

The National Institute of Standards and Technology is developing reference standards through its Office of Law Enforcement Standards with funding provided by the National Institute of Justice. The standard reference materials are used by crime laboratories to verify that results obtained when using their protocols and methodologies meet legal requirements and that equipment is operating properly. The NIST Reference Materials 8240/8250 standard bullets and casings is an example of materials that will assist laboratories in calibrating their instruments and ensuring quality control.The Office of Law Enforcement Standards (OLES) at the National Institute of Standards and Technology (NIST) manages research in many different disciplines of forensic science. One of these projects supports the National Integrated Ballistics Information Network (NIBIN). NIST digitized six bullet signatures from samples provided by the Bureau of Alcohol, Tobacco, and Firearms (ATF) and the Federal Bureau of Investigation (FBI). Using these signatures as a virtual standard, NIST’s Instrument Shop manufactured 20 reference materials (RM) 8240 standard bullets using a numerically-controlled diamond turning machine. Test results show high reproducibility of the bullet signatures on standard bullets. NIST has also developed a new parameter for bullet signature comparisons, using autocorrelation functions, and proposed a diagram for tracing local ballistics measurements to the National Laboratory Center of the ATF and to the FBI. Using an electro-forming process, NIST has manufactured prototype standard casings and test results show high reproducibility for the casing signatures.     

Materials Research With Neutrons at NIST

The NIST Materials Science and Engineering Laboratory works with industry, standards bodies, universities, and other government laboratories to improve the nation’s measurements and standards infrastructure for materials. An increasingly important component of this effort is carried out at the NIST Center for Neutron Research (NCNR), at present the most productive center of its kind in the United States. This article gives a brief historical account of the growth and activities of the Center with examples of its work in major materials research areas and describes the key role the Center can expect to play in future developments.     

Accelerating Scientific Discovery Through Computation and Visualization III. Tight-Binding Wave Functions for Quantum Dots

This is the third in a series of articles that describe, through examples, how the Scientific Applications and Visualization Group (SAVG) at NIST has utilized high performance parallel computing, visualization, and machine learning to accelerate scientific discovery. In this article we focus on the use of high performance computing and visualization for simulations of nanotechnology.     

表面分析技术及其在材料科学中的应用

对表面及其特性尤其是那些与应用材料科学有关的问题作了说明;给出了各种表面分析的方法,以研究的实例,对运用表面科学的观点和表面分析城材料科学中的应用作了简单的介绍。     

Aggregate Science: From Structures to Properties

Molecular science entails the study of structures and properties of materials at the level of single molecules or small interacting complexes of molecules. Moving beyond single molecules and well-defined complexes, aggregates (i.e., irregular clusters of many molecules) serve as a particularly useful form of materials that often display modified or wholly new properties compared to their molecular components. Some unique structures and phenomena such as polymorphic aggregates, aggregation-induced symmetry breaking, and cluster excitons are only identified in aggregates, as a few examples of their exotic features. Here, by virtue of the flourishing research on aggregation-induced emission, the concept of “aggregate science” is put forward to fill the gaps between molecules and aggregates. Structures and properties on the aggregate scale are also systematically summarized. The structure–property relationships established for aggregates are expected to contribute to new materials and technological development. Ultimately, aggregate science may become an interdisciplinary research field and serves as a general platform for academic research.     

A review on measurement science needs for real-time control of additive manufacturing metal powder bed fusion processes

Additive manufacturing technologies are increasingly used in the development of new products. However, variations in part quality in terms of material properties, dimensional tolerances, surface roughness and defects limit its broader acceptance. Process control today based on heuristics and experimental data yields limited improvement in part quality. In an effort to identify the needed measurement science for real-time closed-loop control of additive manufacturing (AM) processes, this paper presents a literature review on the current AM control schemes, process measurements and modelling and simulation methods as it applies to the powder bed fusion process, though results from other processes are reviewed where applicable. We present our research findings to identify the correlations between process parameters, process signatures and product quality. We also present research recommendations on the key control issues to serve as a technical basis for standards development in this area. Complimentary details to this paper with summary tables, range of values, preliminary correlations and correlation figures can be accessed from a National Institute of Standards and Technology Report (http://nvlpubs.nist.gov/nistpubs/ir/2015/NIST.IR.8036.pdf). This paper is developed based on the report.     

The Calibration of dc Voltage Standards at NIST

This document describes the procedures used at NIST to calibrate dc voltage standards in terms of the NIST volt. Three calibration services are offered by the Electricity Division: Regular Calibration Service (RCS) of client standard cells at NIST; the Volt Transfer Program (VTP) a process to determine the difference between the NIST volt and the volt as maintained by a group of standard cells in a client laboratory; and the calibration of client solid-state dc voltage standards at NIST. The operational procedures used to compare these voltage standards to NIST voltage standards and to maintain the NIST volt via the ac Josephson effect are discussed.     

A Brief Review of Recent Superconductivity Research at NIST

A brief overview of recent superconductivity research at NIST is presented. Emphasis is placed on the new high-temperature oxide superconductors, though mention is made of important work on low-temperature superconductors, and a few historical notes are included. NIST research covers a wide range of interests. For the new high-temperature superconductors, research activities include determination of physical properties such as elastic constants and electronic structure, development of new techniques such as magnetic-field modulated microwave-absorption and determination of phase diagrams and crystal structure. For the low-temperature superconductors, research spans studying the effect of stress on current density to the fabrication of a new Josephson junction voltage standard.     

系统科学理论在材料领域的应用

简介了几种重要的系统科学理论,如:耗散结构、突变论、协同论、可拓学、混沌论;给出了几种材料制备、加工和分析的实例,以说明这些系统科学理论在材料研究上的应用;并用系统科学理论分析了电场、磁场、应力场等多场耦合活化烧结新型工艺的研究思路.     

New Program and Directions at the National Institute of Standards and Technology

The Trade Act of 1988 created the National Institute of Standards and Technology (NIST) from the National Bureau of Standards (NBS). In addition to explicitly defining and reconfirming the traditional measurement services, the law assigned new responsibilities to NIST to assist U.S. industry in capitalizing on new technologies developed in the U.S. scientific and technical community at a faster rate. This article decribes the new programs being established at NIST to comply with this mandate and the new organizational unit at NIST that brings together the traditional services and these new programs.     

Through Measurement to Knowledge: The Inaugural Lecture of Heike Kamerlingh Onnes (1882)

This paper is a contribution to the NIST Centennial 2001. It presents the first complete English translation of the inaugural speech of Heike Kamerlingh Onnes on the occasion of his appointment as Professor at the University of Leiden (The Netherlands) in 1882. The speech is a snapshot of the scientific landscape of that time and lays out a vision. It advocates with enthusiasm the significance of quantitative measurements and the development of metrology standards. Although science and technology have advanced since then by orders of magnitude, a number of interesting parallels between then and now appear.     

科技自主创新与中西文化互补之我见——六个典型实例的思考

从中西文化互补的角度，考察了20世纪70年代以来中国科技原始性自主创新的六个典型实例，简述了笔者从事典型信息法研究的几点认识，试图以事实论证：中国传统文化对当代科技自主创新有重大作用，并对其表现形式等做了初步考察。     

知识分类视角下儿童科普游戏的叙事设计与效果验证

目的 基于知识划分理论和查特曼叙事分析框架,探索儿童科普游戏的叙事设计框架。方法 梳理了现有设计问题及成因,分析、构建设计理论框架SPGD;基于该框架自主研发一款以“抗生素耐药性”为主题的RPG科普游戏,将其作为科普学习材料进行干预实验,以确保实验数据能够准确反映理论框架的有效性。结果 实验数据显示,游戏实例能够有效指导儿童科普游戏叙事设计实践,并保证儿童科普学习的主观体验和客观效果。结论 基于SPGD框架开发的科普游戏可以有效提升儿童对特定科普知识的认知效果和科普学习体验。