Reagents for determinations of trace impurities in water—phase II

Determinations of trace impurities, pollutants, in water are often complicated by a large number of factors which consume a great deal of time. Thus, ideal reagents--sensitive, specific, stable, water-soluble reagents--are needed for rapid, spectrophotometric determinations of trace impurities in water. A new method for the determination of nitrate in water is described which uses zinc 1-naphthol-4-sulfonate, an easily prepared, readily purified, stable, water-soluble reagent; the reagent is much better than 1-naphthol-4-sulfonic acid, for the determination of nitrate proposed earlier by another worker and subsequently found in this laboratory to be satisfactory only under very carefully controlled conditions. The same reagent, zinc 1-naphthol-4-sulfonate, also has been proposed for the rapid, specific, sensitive determination of nitrite in natural waters. Nitrite readily can be determined at ppm levels in the presence of several thousand fold excess of nitrate. Full development of water resources, and the control of pollutants returned to natural-water systems, are dependent upon methods of determining trace constituents; significant contributions toward meeting those needs have been accomplished in this work. The methods can readily be applied to such diverse systems as lakes where agricultural fertilizer run-off may be significant, to effluents from plants in the food-preparation industry, and to natural-water systems in highly mineralized areas. Effective new research areas are readily identified as an extension of the work reported here, particularly the study of systems which contain ppm-levels of nitrite in the presence of significant concentrations of nitrate.U.S. Department of the InteriorU.S. Geological SurveyOpe

Note and Comment

Civil Liability for False Testimony; Review by the Courts of the Decisions of the Land Department; Right of One Partner to Sue His Co-Partners in Conversion; Does a Tax Deed, Void on it Face, Give Color of Title; Interference With Employment by Trade Union

Development of a High-Throughput Assay for Identifying Inhibitors of TBK1 and IKKε

IKKε and TBK1 are noncanonical IKK family members which regulate inflammatory signaling pathways and also play important roles in oncogenesis. However, few inhibitors of these kinases have been identified. While the substrate specificity of IKKε has recently been described, the substrate specificity of TBK1 is unknown, hindering the development of high-throughput screening technologies for inhibitor identification. Here, we describe the optimal substrate phosphorylation motif for TBK1, and show that it is identical to the phosphorylation motif previously described for IKKε. This information enabled the design of an optimal TBK1/IKKε substrate peptide amenable to high-throughput screening and we assayed a 6,006 compound library that included 4,727 kinase-focused compounds to discover in vitro inhibitors of TBK1 and IKKε. 227 compounds in this library inhibited TBK1 at a concentration of 10 µM, while 57 compounds inhibited IKKε. Together, these data describe a new high-throughput screening assay which will facilitate the discovery of small molecule TBK1/IKKε inhibitors possessing therapeutic potential for both inflammatory diseases and cancer

The ABCD of usability testing

We introduce a methodology for tracking and auditing feedback, errors and suggestions for software packages. This short paper describes how we innovate on the evaluation mechanism, introducing an (Antecedent, Barrier, Consequence and Development) ABCD form, embedded within an eParticipation platform to enable end users to easily report on any usability issues. This methodology will be utilised to improve the STEP cloud eParticipation platform (part of the current STEP Horizon2020 project http://step4youth.eu. The platform is currently being piloted in real life contexts, with the participation of public authorities that are integrating the eParticipation platform into their regular decision-making practices. The project is involving young people, through engagement and motivation strategies and giving them a voice in Environmental decision making at the local level. The pilot evaluation aims to demonstrate how open engagement needs to be embedded within public sector processes and the usability methodology reported here will help to identify the key barriers for wide scale deployment of the platform

Structural changes in glassy polycarbonate induced by cyclic stresses

Glassy polycarbonate was subjected to cyclic stresses and the changes in its structure were studied by DSC, positronium annihilation lifetime spectroscopy (PALS), and SAXS. On increased exposure to cyclic loading, the enthalpy overshoot near Tg increased in a manner similar to increasing physical aging. However, the `hole' size as revealed by PALS increased, unlike physical aging. SAXS reveals an increase in the short range order and the amplitude of density fluctuation. These results are consistent with both the DSC and the PALS results. We conclude that mechanical loading does cause changes in the glassy structure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29285/1/0000345.pd

Microwave Near-Field Imaging of Two-Dimensional Semiconductors

Optimizing new generations of two-dimensional devices based on van der Waals materials will require techniques capable of measuring variations in electronic properties in situ and with nanometer spatial resolution. We perform scanning microwave microscopy (SMM) imaging of single layers of MoS_2 and n- and p-doped WSe_2. By controlling the sample charge carrier concentration through the applied tip bias, we are able to reversibly control and optimize the SMM contrast to image variations in electronic structure and the localized effects of surface contaminants. By further performing tip bias-dependent point spectroscopy together with finite element simulations, we distinguish the effects of the quantum capacitance and determine the local dominant charge carrier species and dopant concentration. These results underscore the capability of SMM for the study of 2D materials to image, identify, and study electronic defects

Microwave Near-Field Imaging of Two-Dimensional Semiconductors

Optimizing new generations of two-dimensional devices based on van der Waals materials will require techniques capable of measuring variations in electronic properties in situ and with nanometer spatial resolution. We perform scanning microwave microscopy (SMM) imaging of single layers of MoS_2 and n- and p-doped WSe_2. By controlling the sample charge carrier concentration through the applied tip bias, we are able to reversibly control and optimize the SMM contrast to image variations in electronic structure and the localized effects of surface contaminants. By further performing tip bias-dependent point spectroscopy together with finite element simulations, we distinguish the effects of the quantum capacitance and determine the local dominant charge carrier species and dopant concentration. These results underscore the capability of SMM for the study of 2D materials to image, identify, and study electronic defects