X-Ray Tomography To Measure Size Of Fragments From Penetration Of High-Velocity Tungsten Rods

Behind-armor debris that results from tungsten rods penetrating armor steel at 2 km/s was studied by analysis of recovered fragments. Fragment recovery was by means of particle board. Individual fragments were analyzed by x-ray tomography, which provides information for fragment identification, mass, shape, and penetration down to masses of a few milligrams. The experiments were complemented by AUTODYN and EPIC calculations. Fragments were steel or tungsten generated from the channel or from the breakout through the target rear surface. Channel fragment motions were well described by Tate theory. Breakout fragments had velocities from the projectile remnant to the channel velocity, apparently depending on where in the projectile a fragment originated. The fragment size distribution was extremely broad and did not correlate well with simple uniform-fragment-size models.Mechanical Engineerin

Nephrogenic systemic fibrosis risk and liver disease.

Objective. Evaluate the incidence of nephrogenic systemic fibrosis (NSF) in patients with liver disease in the peritransplant period. Materials and Methods. This IRB approved study retrospectively reviewed patients requiring transplantation for cirrhosis, hepatocellular carcinoma (HCC), or both from 2003 to 2013. Records were reviewed identifying those having gadolinium enhanced MRI within 1 year of posttransplantation to document degree of liver disease, renal disease, and evidence for NSF. Results. Gadolinium-enhanced MRI was performed on 312 of 837 patients, including 23 with severe renal failure (GFR < 30 mL/min/1.73 cm(2)) and 289 with GFR > 30. Two of 23 patients with renal failure developed NSF compared to zero NSF cases in 289 patients with GFR > 30 (0/289; P < 0.003). High dose gadodiamide was used in the two NSF cases. There was no increased incidence of NSF with severe liver disease (1/71) compared to nonsevere liver disease (1/241; P = 0.412). Conclusion. Renal disease is a risk factor for NSF, but in our small sample our evidence suggests liver disease is not an additional risk factor, especially if a low-risk gadolinium agent is used. Noting that not all patients received high-risk gadolinium, a larger study focusing on patients receiving high-risk gadolinium is needed to further evaluate NSF risk in liver disease in the peritransplant period

Composite bosons in bilayer nu = 1 system: An application of the Murthy-Shankar formalism

We calculate the dispersion of the out-of-phase mode characteristic for the bilayer nu = 1 quantum Hall system applying the version of Chern-Simons theory of Murthy and Shankar that cures the unwanted bare electron mass dependence in the low-energy description of quantum Hall systems. The obtained value for the mode when d, distance between the layers, is zero is in a good agreement with the existing pseudospin picture of the system. For d nonzero but small we find that the mode is linearly dispersing and its velocity to a good approximation depends linearly on d. This is in agreement with the Hartree-Fock calculations of the pseudospin picture that predicts a linear dependance on d, and contrary to the naive Hartree predictions with dependence on the square-root of d. We set up a formalism that enables one to consider fluctuations around the found stationary point values. In addition we address the case of imbalanced layers in the Murthy-Shankar formalism.Comment: 10 pages, 1 figur

A sol-gel method for growing superconducting MgB2 films

In this paper we report a new sol-gel method for the fabrication of MgB2 films. Polycrystalline MgB2 films were prepared by spin-coating a precursor solution of Mg(BH_4)_2 diethyl ether on (001)Al2O3 substrates followed with annealing in Mg vapor. In comparison with the MgB2 films grown by other techniques, our films show medium qualities including a superconducting transition temperature of Tc ~ 37 K, a critical current density of Jc(5 K, 0 T) ~ 5 {\times} 10^6 A cm^{-2}, and a critical field of H_{c2}(0) ~ 19 T. Such a sol-gel technique shows potential in the commercial fabrication of practically used MgB2 films as well as MgB2 wires and tapes.Comment: 8 pages, 5 figure

Appropriate Transgression: An Intertextual Approach to Problems of Genre and Heroism in Statius' Achilleid

Statius’ second epic poem, the Achilleid, deals with a subject matter that is particularly problematic: Achilles’ early life, in which he is raised by a centaur in the wilderness and then disguises himself as a woman in order to rape the princess of Scyros. Recent scholarship has also pointed to other problematic elements, such as Achilles’ troublesome relationship with his mother or the epic’s intertextual engagement with elegiac and ‘un-epic’ poetry. This thesis extends such scholarship by analysing Statius’ use of transgression in particular. It focuses primarily upon the heroic character of Achilles and the generic program of the Achilleid as a whole. The first chapter focuses upon Achilles’ childhood and early youth as a foster child and student of the centaur Chiron. It demonstrates that the hero’s upbringing is used to emphasise his ambiguous nature in line with the Homeric Iliad, as a hero who is capable of acting appropriately, but chooses not to. Achilles’ wild and bestial nature is emphasised by its difference to the half-human character of Chiron, who might be expected to be act like an animal, but instead becomes an example of civilisation overcoming innate savagery, an example of what Achilles could have been. The second chapter discusses the ambiguities inherent in a study of transgression, in the light of Achilles’ transvestite episode on Scyros. Numerous intertextual allusions construct various sets of expected behaviours for the transvestite youth, but his failure to live up to any of them portrays him as a truly transgressive hero. In this way, he is similar to Hercules or Bacchus, whose heroism is constructed partly upon their transgressive natures and inability to conform to societal custom. In the final chapter, the study of transgression is extended to Statius’ generic program, associating the epic with elegy. Statius employs many elegiac tropes, and makes numerous allusions to the poetry of elegists such as Ovid and Propertius. In particular, elegiac poetry’s peculiar trope of constructing and emphasising boundaries in order that they may be crossed (thus making the poetry feel more transgressive) is mirrored in the Achilleid. In this way, the Achilleid’s engagement with transgression is considered to be, in part, a method for presenting an innately problematic hero to Statius’ Flavian audience in an accessible and interesting manner

A survey of attitudes, practices, and knowledge regarding drug-drug interactions among medical residents in Iran

Background When prescribing medications, physicians should recognize clinically relevant potential drug–drug interactions (DDIs). To improve medication safety, it is important to understand prescribers’ knowledge and opinions pertaining to DDIs. Objective To determine the current DDI information sources used by medical residents, their knowledge of DDIs, their opinions about performance feedback on co-prescription of interacting drugs. Setting Academic hospitals of Mashhad University of Medical Sciences (MUMS) in Iran. Methods A questionnaire containing questions regarding demographic and practice characteristics, DDI information sources, ability to recognize DDIs, and opinions about performance feedback was distributed to medical residents of 22 specialties in eight academic hospitals in Iran. We analyzed their perception pertaining to DDIs, their performance on classifying drug pairs, and we used a linear regression model to assess the association of potential determinants on their DDI knowledge. Main Outcome Measure prescribers’ knowledge and opinions pertaining to DDIs. Results The overall response rate and completion rate for 315 distributed questionnaires were 90% (n = 295) and 86% (n = 281), respectively. Among DDI information sources, books, software on mobile phone or tablet, and Internet were the most commonly-used references. Residents could correctly classify only 41% (5.7/14) of the drug pairs. The regression model showed no significant association between residents’ characteristics and their DDI knowledge. An overwhelming majority of the respondents (n = 268, 95.4%) wished to receive performance feedback on co-prescription of interacting drugs in their prescriptions. They mostly selected information technology-based tools (i.e. short text message and email) as their preferred method of receiving feedback. Conclusion Our findings indicate that prescribers may have poor ability to prevent clinically relevant potential DDI occurrence, and they perceive the need for performance feedback. These findings underline the importance of well-designed computerized alerting systems and delivering performance feedback to improve patient safety