The Ampere and Electrical Standards

This paper describes some of the major contributions to metrology and physics made by the NIST Electricity Division, which has existed since 1901. It was one of the six original divisions of the National Bureau of Standards. The Electricity Division provides dc and low-frequency calibrations for industrial, scientific, and research organizations, and conducts research on topics related to electrical metrology and fundamental constants. The early work of the Electricity Division staff included the development of precision standards, such as Rosa and Thomas standard resistors and the ac-dc thermal converter. Research contributions helped define the early international system of measurement units and bring about the transition to absolute units based on fundamental principles and physical and dimensional measurements. NIST research has helped to develop and refine electrical standards using the quantum Hall effect and the Josephson effect, which are both based on quantum physics. Four projects covering a number of voltage and impedance measurements are described in detail. Several other areas of current research at NIST are described, including the use of the Internet for international compatibility in metrology, determination of the fine-structure and Planck constants, and construction of the electronic kilogram.     

A study of genetic and environmental effects on the co-occurrence of problem behaviors in three-year-old-twins.

The authors examined the genetic and environmental causes of the co-occurrence of problem behaviors in children. The analyses involved mother and father ratings of Oppositional, Withdrawn/Depressed, Aggressive, Anxious, Overactive, and Sleep Problems in 446 monozygotic and 912 dizygotic pairs of 3-year-old twins. Genetic factors contributed on average .150 (37.3%), shared environment .206 (51.2%), and nonshared environment .046 (11.4%) to the phenotypic correlations between the syndromes. Genetic and environmental factors caused different groupings. Internalizing and Externalizing groupings were indicative of nonshared environmental factors; clusters of problem behaviors with either the Aggressive or Anxious symptoms were most suggestive of genetic factors, and high scores on all syndromes indicated shared environmental influences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

In Situ Raman Indentation of β-Eucryptite: Characterization of the Pressure-Induced Phase Transformation

A pressure-induced phase transformation in the lithium aluminum silicate β-eucryptite was studied with in situ Raman spectroscopy. Dense β-eucryptite composites were made via powder synthesis followed by sintering. The specimens were then subjected to diamond indentation up to applied contact stresses of about 8 GPa, while collecting Raman spectra. The appearance of a Raman peak (∼520 cm⁻¹) at a contact stress of about 3 GPa likely corresponds to the reversible phase transformation of β-eucryptite to the orthorhombic phase ɛ-eucryptite. Loading and unloading in situ Raman indentation experiments are discussed with regards to this transformation.     

EMDR for panic disorder with agoraphobia: Comparison with waiting list and credible attention-placebo control conditions.

In a randomized controlled trial, eye movement desensitization and reprocessing (EMDR) for panic disorder with agoraphobia (PDA) was compared with both waiting list and credible attention-placebo control groups. EMDR was significantly better than waiting list for some outcome measure, (questionnaire, diary, and interview measures of severity of anxiety, panic disorder, and agoraphobia) but not for others (panic attack frequency and anxious cognitions). However, low power and, for panic frequency, floor effects may account for these negative results. Differences between EMDR and the attention placebo control condition were not statistically significant on any measure, and, in this case, the effect sizes were generally small (η?=?.00–.06), suggesting the poor results for EMDR were not due to lack of power. Because there are established effective treatments such as cognitive–behavior therapy for PDA, these data, unless contradicted by future research, indicate EMDR should not be the first-line treatment for this disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clicking not cooking: Functionalization of 2,2′:6′,2″-terpyridines by diol–boric acid interactions

A diol–boric acid condensation is a simple type of CLICK reaction that can be applied to give a family of related ligands. It is exemplified by the reaction of 4′-(3,4-dihydroxyphenyl)-2,2′:6′,2″-terpyridine (1) with naphthalene-1-boronic acid. The single crystal structures of 1^.MeOH and [Fe(1)₂][BF₄]₂? 4H₂O?0.2CH₃CN are presented.     

Furan formation from vitamin C in a starch-based model system: Influence of the reaction conditions

The generation of furan from vitamin C during thermal treatment of a starch-based model system, which simulated baby food, was studied. Results indicated that the amount of sample heated in the vial influenced the furan generation from ascorbic acid. Increasing the amount of heated sample from 5% to approximately 98% of the total vial volume, drastically reduced furan formation from 70 ppb to 16 ppb. Changes in ascorbic acid concentrations from 0.1 to 4.5 mg/g did not influence furan concentration nor did different ascorbic/dehydroascorbic acid molar ratios. Interestingly, waxy corn starch itself considerably enhanced furan generation from ascorbic acid. Under the same conditions, 13.2 ppb of furan was generated in starch-based samples, while in ascorbic acid buffered solutions only 0.4 ppb of furan was formed. Application of other matrices, in particular agar and hydrolysed starch, resulted in similar furan concentrations as for native starch, while in polyol solutions furan concentrations were comparable to those obtained for the buffered ascorbic acid solutions.     

Nested maximin Latin hypercube designs

In the field of design of computer experiments (DoCE), Latin hypercube designs are frequently used for the approximation and optimization of black-boxes. In certain situations, we need a special type of designs consisting of two separate designs, one being a subset of the other. These nested designs can be used to deal with training and test sets, models with different levels of accuracy, linking parameters, and sequential evaluations. In this paper, we construct nested maximin Latin hypercube designs for up to ten dimensions. We show that different types of grids should be considered when constructing nested designs and discuss how to determine which grid to use for a specific application. To determine nested maximin designs for dimensions higher than two, four variants of the ESE algorithm of Jin et al. (J Stat Plan Inference 134(1):268–287, 2005) are introduced and compared. Our main focus is on GROUPRAND, the most successful of these four variants. In the numerical comparison, we consider the calculation times, space-fillingness of the obtained designs and the performance of different grids. Maximin distances for different numbers of points are provided; the corresponding nested maximin designs can be found on the website .     

New Coupling Agents for Improved Corrosion-Resistant Composites

The major progress in fiberglass-reinforced polyester composites since the 1940s has been attributed to the development of silane coupling agents that improve the bond across the interface [1]. Among the best coupling agents for polyesters is 3-methacryloxypropyltrimethoxysilane (γ-MPS), first described in 1962 (Fig. 1). Other methacrylate-functional silane coupling agents show comparable coupling activity in fiberglass reinforced general purpose polyester composites [2] (Table 1). The bond between glass and polyester with these coupling agents was “perfect,” i.e., fracture surfaces after 2-h water boil showed essentially no interfacial bond failure.     

Determination of Semivolatile Organic Compounds in Particles in the Grand Canyon Area

Several diffusion denuder-filter-sorbent bed and filter-sorbent bed sampling systems with varying selectivity for the collection of different classes of organic compounds have been used for the collection and determination of atmospheric organic material present at Hopi Point in the Grand Canyon. The data show that the amount of semivolatile organic compounds in particles in the atmosphere in the Southwest United States has been underestimated by sampling with only a filter. The collection of gas-phase organic compounds by the filter causes a small positive artifact. However, a much larger, negative error results from the loss of 40%–80% of the organic material in the particles collected by the filter. The concentration of organic particulate matter present at the Hopi Point site is probably about 2 μg/m³ larger than inferred from previous data.