TNT equivalence of C-4 and PE4: a review of traditional sources and recent data

Since standard engineering-level blast models are typically developed to predict airblast parameters (pressure and impulse) from TNT bursts, prediction of airblast from other materials uses an equivalence factor by which an equivalent TNT weight is computed and used in the source term of the model. This approach is widespread in the industry and has been codified in numerous manuals, books, and papers. A recent effort co-sponsored by TSWG (U.S.) and FSTD (Singapore) collected and compiled equivalence data for a wide variety of explosive materials (both military grade as well as home-made) into a single software tool named STREET. The database thus assembled provides a comprehensive and expandable repository for equivalence data. Two of the main achievements in STREET are the consideration of equivalence as a function of scaled standoff (rather than a scalar), and the documentation of uncertainty in the estimated value. In this paper, we consider specifically the manual- and test-derived data related to Composition C-4, and as a first step, we draw some judgments regarding the equivalence implicit in blast curves provided by UFC 3-340-02, for both pressure and impulse. Next, we consider PE4, which is similar in composition to C-4 and is used widely in the UK. A significant body of blast data for this explosive has been generated, from which equivalence is computed and is compared to the available data for C-4, with a view towards determining whether these two materials can in fact be considered as a single explosive (with two alternate names). Finally, considering the combined data for both C-4 and PE4, new curve fits are provided that represent the pressure and impulse equivalence of the C-4/PE4 material (and its uncertainty) as a function of scaled standoff

Spectrum of Relativistic Fermions in a 2d Doped Lattice

Motivated by some previous work on fermions on random lattices and by suggestions that impurities could trigger parity breaking in 2d crystals, we have analyzed the spectrum of the Dirac equation on a two dimensional square lattice where sites have been removed randomly --- a doped lattice. We have found that the system is well described by a sine-Gordon action. The solitons of this model are the lattice fermions, which pick a quartic interaction due to the doping and become Thirring fermions. They also get an effective mass different from the lagrangian mass. The system seems to exhibit spontaneous symmetry breaking, exactly as it happens for a randomly triangulated lattice. The associated ``Goldstone boson" is the sine-Gordon scalar. We argue, however, that the peculiar behaviour of the chiral condensate is due to finite size effects.Comment: 11 page

Fast multipole networks

Two prerequisites for robotic multiagent systems are mobility and communication. Fast multipole networks (FMNs) enable both ends within a unified framework. FMNs can be organized very efficiently in a distributed way from local information and are ideally suited for motion planning using artificial potentials. We compare FMNs to conventional communication topologies, and find that FMNs offer competitive communication performance (including higher network efficiency per edge at marginal energy cost) in addition to advantages for mobility

Estimation of Spin-Spin Interaction by Weak Measurement Scheme

Precisely knowing an interaction Hamiltonian is crucial to realize quantum information tasks, especially to experimentally demonstrate a quantum computer and a quantum memory. We propose a scheme to experimentally evaluate the spin-spin interaction for a two-qubit system by the weak measurement technique initiated by Yakir Aharonov and his colleagues. Furthermore, we numerically confirm our proposed scheme in a specific system of a nitrogen vacancy center in diamond. This means that the weak measurement can also be taken as a concrete example of the quantum process tomography.Comment: 4 pages, 1 table, 2 figures, to appear in Europhysics Letter

Women’s impressions of their inpatient birth care as provided by family physicians in the Shizuoka Family Medicine Training Program in Japan

Abstract Background Even though Japan faces serious challenges in women’s health care such as a rapidly aging population, attrition of obstetrical providers, and a harsh legal climate, few family medicine residency training programs in Japan include training in obstetrics, and the literature lacks research on women’s views of intra-partum pregnancy care by family physicians. Findings In this exploratory study, we conducted semi-structured qualitative interviews with five women who received their admission, intrapartum, delivery and discharge care from family medicine residents in the obstetrics ward of a community training hospital. Four women had vaginal births, and one had a Cesarean section. Three were primiparous, and two multiparous. Their ages ranged from 22–33. They found value in family physician medical knowledge and easy communication style, though despite explanation, some had trouble understanding the family physician’s scope of work. These women identified negative aspects of the hospital environment, and wanted more anticipatory guidance about what to expect physically after birth, but were enthusiastic about seeing a family doctor after discharge. Conclusions These results demonstrate the feasibility of family medicine residents providing inpatient birth care in a community hospital, and that patients are receptive to family physicians providing that care as well after discharge. Women’s primary concerns relate mostly to hospital environment issues, and better understanding the care family physicians provide. This illustrates-areas for family physicians to work for improvements.http://deepblue.lib.umich.edu/bitstream/2027.42/112408/1/12930_2012_Article_51.pd

Mature natural killer cell and lymphoid tissue–inducing cell development requires Id2-mediated suppression of E protein activity

The Id2 transcriptional repressor is essential for development of natural killer (NK) cells, lymphoid tissue–inducing (LTi) cells, and secondary lymphoid tissues. Id2 was proposed to regulate NK and LTi lineage specification from multipotent progenitors through suppression of E proteins. We report that NK cell progenitors are not reduced in the bone marrow (BM) of Id2−/− mice, demonstrating that Id2 is not essential for NK lineage specification. Rather, Id2 is required for development of mature (m) NK cells. We define the mechanism by which Id2 functions by showing that a reduction in E protein activity, through deletion of E2A, overcomes the need for Id2 in development of BM mNK cells, LTi cells, and secondary lymphoid tissues. However, mNK cells are not restored in the blood or spleen of Id2−/−E2A−/− mice, suggesting a role for Id2 in suppression of alternative E proteins after maturation. Interestingly, the few splenic mNK cells in Id2−/− and Id2−/−E2A−/− mice have characteristics of thymus-derived NK cells, which develop in the absence of Id2, implying a differential requirement for Id2 in BM and thymic mNK development. Our findings redefine the essential functions of Id2 in lymphoid development and provide insight into the dynamic regulation of E and Id proteins during this process

Residual Energies after Slow Quantum Annealing

Features of the residual energy after the quantum annealing are investigated. The quantum annealing method exploits quantum fluctuations to search the ground state of classical disordered Hamiltonian. If the quantum fluctuation is reduced sufficiently slowly and linearly by the time, the residual energy after the quantum annealing falls as the inverse square of the annealing time. We show this feature of the residual energy by numerical calculations for small-sized systems and derive it on the basis of the quantum adiabatic theorem.Comment: 4 pages, 2 figure

Weak Values with Decoherence

The weak value of an observable is experimentally accessible by weak measurements as theoretically analyzed by Aharonov et al. and recently experimentally demonstrated. We introduce a weak operator associated with the weak values and give a general framework of quantum operations to the W operator in parallel with the Kraus representation of the completely positive map for the density operator. The decoherence effect is also investigated in terms of the weak measurement by a shift of a probe wave function of continuous variable. As an application, we demonstrate how the geometric phase is affected by the bit flip noise.Comment: 17 pages, 3 figure

All the Exact Solutions of Generalized Calogero-Sutherland Models

A collective field method is extended to obtain all the explicit solutions of the generalized Calogero-Sutherland models that are characterized by the roots of all the classical groups, including the solutions corresponding to spinor representations for $B_N$ and $D_N$ cases.Comment: Latex, 17 pages. Title and abstract slightly changed, plus minor correction