14,955 research outputs found
A review of the mallet impact test for small scale explosive formulations
Presented at 19th Seminar on New Trends of Energetic Materials (NTREM 2016); 20-22/04/2016, Pardubice Czech RepublicDevelopment of new explosive formulations begins with the generation of only a few milligrams of material which is investigated using a number of small scale tests such as DSC, TGA, response to flame, mallet impact (mallet friction either glancing or direct blow) to determine whether the formulation is safe to scale up to 10 g. The latter of these tests, mallet impact, can be particularly subjective as the result is directly influenced by the operator carrying out the assessment. Not only can there be a change from one operator to another but there can also be a change in the force applied during each strike potentially leading to inconsistent results. This study highlights this encountered variation and assesses the load applied by a variety of operators with varying levels of explosive experience. This paper also proposes the use of a small scale laboratory based impact test which would provide improved confidence in the assessment of impact sensitiveness of explosive formulations and assist in justifying whether a formulation can be taken to the next scale. A small scale version of the BAM impact test (EMTAP Test 43) has been devised that allows the comparison of the sensitiveness of small scale formulations relative to RDX (8.7 J, EMTAP Test 43B) whilst also ensuring a reproducible result
Isotropic-medium three-dimensional cloaks for acoustic and electromagnetic waves
We propose a generalization of the two-dimensional eikonal-limit cloak
derived from a conformal transformation to three dimensions. The proposed cloak
is a spherical shell composed of only isotropic media; it operates in the
transmission mode and requires no mirror or ground plane. Unlike the well-known
omnidirectional spherical cloaks, it may reduce visibility of an arbitrary
object only for a very limited range of observation angles. In the
short-wavelength limit, this cloaking structure restores not only the
trajectories of incident rays, but also their phase, which is a necessary
ingredient to complete invisibility. Both scalar-wave (acoustic) and transverse
vector-wave (electromagnetic) versions are presented.Comment: 17 pages, 12 figure
Effects of dietary inclusion of palm kernel cake and palm oil, and enzyme supplementation on performance of laying hens.
A total of 392 twenty eight week-old laying hens was used to study the effects of dietary inclusion of solvent extracted palm kernel cake (PKC) (0%, 12.5% and 25%) and enzyme (mixture of mannanase, α-galactosidase and protease) supplementation (0 kg/t, 1 kg/t and 2 kg/t) on the performance of laying hens. The levels of PKC did not significantly influence nitrogen corrected true metabolizable energy (TMEn) of the diets. Enzyme supplemented PKC had significantly higher AME and TMEn values than PKC diets with no enzyme supplementation. Dietary inclusion of 12.5% and 25% PKC in the diets of laying hens did not adversely affect mean egg production or daily egg mass. However, layers consumed significantly more PKC-based diets and had significantly poorer feed conversion ratios (FCR) than controls. However, the feed intake and FCR of hens provided the 12.5% PKC-based diets with enzyme supplementation at 1 kg/t did not differ from the controls. Dietary inclusion of PKC or enzyme did not affect eggshell quality, but egg yolk colour was significantly paler when layers were fed the 25% PKC diet
The long road of statistical learning research: past, present and future
Published 21 November 2016
http://rstb.royalsocietypublishing.org/content/372/1711/20160047http://rstb.royalsocietypublishing.org/content/372/1711/20160047This paper was supported by the Israel Science Foundation
(grant no. 217/14 awarded to R.F.), by the National Institute of
Child Health and Human Development (RO1 HD 067364 awarded
to Ken Pugh and R.F., PO1-HD 01994 awarded to Haskins Laboratories)
and by the European Research Council (project ERC-ADG-
692502 awarded to R.F.)
Molecular dynamics simulations of apo and holo forms of fatty acid binding protein 5 and cellular retinoic acid binding protein II reveal highly mobile protein, retinoic acid ligand, and water molecules
Structural and dynamic properties from a series of 300 ns molecular dynamics, MD, simulations of two intracellular lipid binding proteins, iLBPs, (Fatty Acid Binding Protein 5, FABP5, and Cellular Retinoic Acid Binding Protein II, CRABP-II) in both the apo form and when bound with retinoic acid reveal a high degree of protein and ligand flexibility. The ratio of FABP5 to CRABP-II in a cell may determine whether it undergoes natural apoptosis or unrestricted cell growth in the presence of retinoic acid. As a result, FABP5 is a promising target for cancer therapy. The MD simulations presented here reveal distinct differences in the two proteins and provide insight into the bindingmechanism. CRABP-II is a much larger, more flexible protein that closes upon ligand binding, where FABP5 transitions to an open state in the holo form. The traditional understanding obtained from crystal structures of the gap between two β-sheets of the β-barrel common to iLBPs and the α-helix cap that forms the portal to the binding pocket is insufficient for describing protein conformation (open vs. closed) or ligand entry and exit. When the high degree of mobility between multiple conformations of both the ligand and protein are examined via MD simulation, a new mode of ligand motion that improves understanding of binding dynamics is revealed
How are visual words represented? Insights from EEG-based visual word decoding, feature derivation and image reconstruction
Issue Online: 23 October 2019Investigations into the neural basis of reading have shed light on the cortical locus
and the functional role of visual-orthographic processing. Yet, the fine-grained structure
of neural representations subserving reading remains to be clarified. Here, we
capitalize on the spatiotemporal structure of electroencephalography (EEG) data to
examine if and how EEG patterns can serve to decode and reconstruct the internal
representation of visually presented words in healthy adults. Our results show that
word classification and image reconstruction were accurate well above chance, that
their temporal profile exhibited an early onset, soon after 100 ms, and peaked around
170 ms. Further, reconstruction results were well explained by a combination of
visual-orthographic word properties. Last, systematic individual differences were
detected in orthographic representations across participants. Collectively, our results
establish the feasibility of EEG-based word decoding and image reconstruction. More
generally, they help to elucidate the specific features, dynamics, and neurocomputational
principles underlying word recognition.This research was supported by the Natural Sciences and Engineering Research Council of Canada (to A.N., A.C.H.L., and B. C. A.)
Pharmacist-led management of chronic pain in primary care:results from a randomised controlled exploratory trial
To compare the effectiveness of pharmacist medication review, with or without pharmacist prescribing, with standard care, for patients with chronic pain
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