Experimental Test bed to De-Risk the Navy Advanced Development Model

This paper presents a reduced scale demonstration test-bed at the University of Texas’ Center for Electromechanics (UT-CEM) which is well equipped to support the development and assessment of the anticipated Navy Advanced Development Model (ADM). The subscale ADM test bed builds on collaborative power management experiments conducted as part of the Swampworks Program under the US/UK Project Arrangement as well as non-military applications. The system includes the required variety of sources, loads, and controllers as well as an Opal-RT digital simulator. The test bed architecture is described and the range of investigations that can be carried out on it is highlighted; results of preliminary system simulations and some initial tests are also provided. Subscale ADM experiments conducted on the UT-CEM microgrid can be an important step in the realization of a full-voltage, full-power ADM three-zone demonstrator, providing a test-bed for components, subsystems, controls, and the overall performance of the Medium Voltage Direct Current (MVDC) ship architecture.Center for Electromechanic

2,6-Diiodo-4-nitrophenol, 2,6-diiodo-4-nitrophenyl acetate and 2,6-diiodo-4-nitroanisole: interplay of hydrogen bonds, iodo-nitro interactions and aromatic [pi]-[pi]-stacking interactions to give supramolecular structures in one, two and three dimensions

Peer reviewedPublisher PD

Falloff of the Weyl scalars in binary black hole spacetimes

The peeling theorem of general relativity predicts that the Weyl curvature scalars Psi_n (n=0...4), when constructed from a suitable null tetrad in an asymptotically flat spacetime, fall off asymptotically as r^(n-5) along outgoing radial null geodesics. This leads to the interpretation of Psi_4 as outgoing gravitational radiation at large distances from the source. We have performed numerical simulations in full general relativity of a binary black hole inspiral and merger, and have computed the Weyl scalars in the standard tetrad used in numerical relativity. In contrast with previous results, we observe that all the Weyl scalars fall off according to the predictions of the theorem.Comment: 7 pages, 3 figures, published versio

The 1:1 co-crystal of 2-bromonaphthalene-1,4-dione and 1,8-dihydroxyanthracene-9,10-dione: crystal structure and Hirshfeld surface analysis

The asymmetric unit of the title co-crystal, C10H5BrO2·C14H8O4 [systematic name: 2-bromo-1,4-dihydronaphthalene-1,4-dione–1,8-dihydroxy-9,10-dihydroanthracene-9,10-dione (1/1)], features one molecule of each coformer. The 2-bromonaphthoquinone molecule is almost planar [r.m.s deviation of the 13 non-H atoms = 0.060 Å, with the maximum deviations of 0.093 (1) and 0.099 (1) Å being for the Br atom and a carbonyl-O atom, respectively]. The 1,8-dihydroxyanthraquinone molecule is planar (r.m.s. deviation for the 18 non-H atoms is 0.022 Å) and features two intramolecular hydroxy-O—H...O(carbonyl) hydrogen bonds. Dimeric aggregates of 1,8-dihydroxyanthraquinone molecules assemble through weak intermolecular hydroxy-O—H...O(carbonyl) hydrogen bonds. The molecular packing comprises stacks of molecules of 2-bromonaphthoquinone and dimeric assembles of 1,8-dihydroxyanthraquinone with the shortest π–π contact within a stack of 3.5760 (9) Å occurring between the different rings of 2-bromonaphthoquinone molecules. The analysis of the Hirshfeld surface reveals the importance of the interactions just indicated but, also the contribution of additional C—H...O contacts as well as C=O...π interactions to the molecular packing

1,3-Bis(4-bromo­phen­yl)imidazolium chloride dihydrate

In the title hydrated salt, C15H11Br2N2 +·Cl−·2H2O, the complete imidazolium cation is generated by a crystallographic twofold axis, with one C atom lying on the axis. The chloride ion and both water mol­ecules of crystallization also lie on a crystallographic twofold axis of symmetry. The cation is non-planar, the dihedral angle formed between the central imidazolium and benzene rings being 12.9 (3)°; the dihedral angle between the symmetry-related benzene rings is 25.60 (13)°. In the crystal, O—H⋯Cl hydrogen bonds result in supra­molecular chains along c mediated by eight-membered {⋯HOH⋯Cl}2 synthons. These are consolidated by C—H⋯O and π–π [centroid–centroid distance = 3.687 (3) Å] inter­actions

MEASUREMENT OF SMALLHOLDER TREE FARMS ON LEYTE ISLAND

This paper describes the field techniques used to measure timber volume and log quality from smallholder tree farms on Leyte Island conducted as part of ACIAR project ASEM/2003/052, Improving Financial Returns from Smallholder Tree Farms in the Philippines . Tree farms were included in the sample if they were 0.1 ha or greater in area and contained 100 or more trees. Paired circular blocks were chosen for measurement, one in the centre and one on the edge of the tree block. Where tree farms included multiple blocks of trees, two circular plots were established within each block. For each tree over 10 cm diameter at breast height (dbh) in the plot, measurements were made of dbh, diameter at the base (db), tree height, location, crown depth, crown radius, bearing and distance of each tree with reference to the plot centre. Estimates of log lengths and grade that each tree was expected to yield were also recorded, along with a sketch of each tree. In addition, data were collected on tree farm, block and plot characteristics, and were entered into an ACCESS database for subsequent analysis

Improving the triple bottom line returns from smallholder tree farms in the Philippines: A systems approach

This paper outlines the application of systems thinking in investigating ways to improve the returns to smallholder tree farmers in the Philippines. The paper illustrates how a systems approach was used in the conceptualisation of the project and how systems thinking facilitated a shared understanding of the how each individual’s research contributed to the broader project activities. Systems thinking has also been used in the design and implementation of various project activities. Three examples are provided. The first example illustrates how a systems diagram was developed which outlined the direct and indirect linkages between biophysical data on tree farms and various activities designed to increase returns. The second example illustrates how the suggested approach for improving the flow of information concerning tree registration, harvest and transportation regulations and approval mechanisms link with various project activities and have been informed by a series of action research workshops. The third example illustrates how systems thinking has been applied to understand the factors affecting the production of high quality tree seedlings and to investigate the effect of policy interventions on improving the quality of seedlings available to smallholders

Methyl 1-{4-[(S)-2-(meth­oxy­carbon­yl)pyrrolidin-1-yl]-3,6-dioxocyclo­hexa-1,4-dien-1-yl}pyrrolidine-2-carboxyl­ate

The complete mol­ecule of the title diproline ester quinone, C18H22N2O6, is generated by a crystallographic twofold axis, which passes through the centre of the benzene ring. Both –CO2Me groups are orientated to the same side of the benzene ring, with the carbonyl groups pointing roughly towards each other. The conformation of the proline residue is an envelope. In the crystal, a three-dimensional network is sustained by C—H⋯O inter­actions involving both the quinone and carbonyl O atoms