Design optimization of a slotless PM brushless motor with spiral wound laminations for rim driven thrusters

This paper discusses the analysis and design of a very thin slotless PM brushless motor whose stator laminations are manufactured from a single strip of steel that is edge wound into a spiral (like a “Slinky”) and then fitted over the windings that are preformed on the outside surface of a non-conducting former. Analytical and finite element analysis (FEA) are used to determine the constrained optimum dimensions of a motor used to drive a rim driven thruster in which the motor rotor is fitted onto the rim of the propeller and the stator is encapsulated in the thin Kort nozzle of the thruster. The paper describes the fabrication of a demonstrator motor and presents experimental results to validate the theoretical calculations. Experimental motor performance esults are also reported and compared with those of a slotted motor that fits within the same active radial dimensions as the slotless motor. The slotless motor, which has longer active length and endwindings, and thicker magnets than the slotted motor, was found to be less efficient and more expensive (prototype cost) than the slotted machine

Capturing a c2 daisy chain using the threading-followed-by-swelling approach

We have used the "threading-followed-by-swelling'' approach to fix a daisy chain structure in solution, leading to the isolation of a captured [c2] daisy chain in 77% yield

Field tests on a grease trap effluent filter

This study investigates the field performance tests of a commercial grease trap effluent filter for removal of total suspended solids, and oil and grease discharged from the clear zone of full service restaurant grease traps. The grease trap effluent filters were installed on 1,000-gallon, 2,000-gallon and 5,400-gallon full service restaurant grease traps over a period of 8 weeks, and samples were taken at the inlets and outlets. On average, the effluent filters demonstrated to be capable of removing 41% to 57% of TSS, and 43% to 52% of O and G. Field test data also showed that the total amount of TSS removed by the grease trap effluent filter installed on 1,000 gallon, 2,000 gallon and 5,400 gallon grease traps were approximately 2,542 kg, 709 kg, and 2,319 kg, respectively; and the total amount of O and G removed over the same period were approximately 1,104 kg, 271 kg, and 897 kg, respectivel

Using a Threading-Followed-by-Swelling Approach to Synthesize 2 Rotaxanes

We have developed a "threading-followed-by-swelling" protocol to synthesize [2]rotaxanes efficiently and atom economically. Our protocol employs cis-1-[(Z)-alk-1'enyl]-2-vinylcyclopropane units as the termini of the threadlike components; these end groups are converted into more-sizable cycloheptadiene motifs, which function as stopper units, through Cope rearrangements at elevated temperature. We used this approach to synthesize [2]rotaxanes in good yield from [2]pseudorotaxanes featuring either one or two swellable termini to interlock three different types of macrocycle. The chiral centers created by the swelling process were "erased" by hydrogenating the cycloheptadiene termini into the corresponding cycloheptane units, affording achiral molecular [2]rotaxanes as the only final products

Evaluating the feasibility of prison officers providing guided self-help support to adult male offenders experiencing stress

With substantial mental health needs, United Nations guidelines recommend prisoners should have access to healthcare of the same standard as non-prisoners. CBT-based self-help is recommended for anxiety and depression; one approach is Living Life To The Full (LLTTFTM). This study evaluated the feasibility of Prison Officers providing guided self-help support to adult male offenders experiencing distress in a Scottish prison. Prison Officers attended training in delivering LLTTF books and worksheets. Seven prisoners completed four one-to-one sessions of LLTTF. A large effect size was associated with improving depression self-ratings pre- to post-treatment. Pre-treatment anxiety and social function were associated with non-significant change. Feedback from Prison Officers and prisoners indicated LLTTF materials would benefit from adaptation for prison, which could be revised with Prison Officers and prisoners. Results suggest further research on guided self-help in prison is worth pursuing. Designated guided self-help workers may be better placed to deliver LLTTF in this or an educational setting

Topology of the conceptual network of language

We define two words in a language to be connected if they express similar concepts. The network of connections among the many thousands of words that make up a language is important not only for the study of the structure and evolution of languages, but also for cognitive science. We study this issue quantitatively, by mapping out the conceptual network of the English language, with the connections being defined by the entries in a Thesaurus dictionary. We find that this network presents a small-world structure, with an amazingly small average shortest path, and appears to exhibit an asymptotic scale-free feature with algebraic connectivity distribution.Comment: 4 pages, 2 figures, Revte

Novel family- and genus-specific DNA markers in Mugilidae

In this study, we identified novel family- and genus-specific DNA markers in Mugilidae fish. Genomic DNA was isolated from the blood of fish of 15 families and eighty (80) random primers were used for random amplified polymorphic DNA (RAPD) fingerprinting. When the primer OPAV04 was employed, a novel specific PCR product was observed in the Mugilidae family. In addition, another novel specific PCR product was also observed in the Liza genus while using primer OPAV10. Sequencing analysis revealed that the novel family- and genus-specific DNA fragments were 857 and 419 bp, respectively, and no similar sequences were found in GenBank. Two primers sets were designed based on the family- and genus-specific sequences to confirm the RAPD results and the 571 and 187 bp predicted bands were successfully amplified by PCR. Intriguingly, these two novel specific DNA markers were also effectively used for terrestrial and aquatic animal discrimination. Therefore, the novel family- and genus-specific DNA markers identified in this study can be used as an effective tool for rapid and accurate determination of the Mugilidae family and Liza genus, and even for cross-species identification

Warp propagation in astrophysical discs

Astrophysical discs are often warped, that is, their orbital planes change with radius. This occurs whenever there is a non-axisymmetric force acting on the disc, for example the Lense-Thirring precession induced by a misaligned spinning black hole, or the gravitational pull of a misaligned companion. Such misalignments appear to be generic in astrophysics. The wide range of systems that can harbour warped discs - protostars, X-ray binaries, tidal disruption events, quasars and others - allows for a rich variety in the disc's response. Here we review the basic physics of warped discs and its implications.Comment: To be published in Astrophysical Black Holes by Haardt et al., Lecture Notes in Physics, Springer 2015. 19 pages, 2 figure