On High Explosive Launching of Projectiles for Shock Physics Experiments

The hydrodynamic operation of the `Forest Flyer' type of explosive launching system for shock physics projectiles was investigated in detail using one- and two-dimensional continuum dynamics simulations. The simulations were insensitive to uncertainties in the material properties, and reproduced measurements of the projectile. The most commonly-used variant, with an Al alloy case, was predicted to produce a slightly curved projectile, subjected to some shock heating, and likely exhibiting some porosity from tensile damage. The flatness can be improved by using a case of lower shock impedance, such as polymethyl methacrylate. High-impedance cases, including Al alloys but with denser materials improving the launching efficiency, can be used if designed according to the physics of oblique shock reflection. The tensile stress induced in the projectile depends on the relative thickness of the explosive, expansion gap, and projectile. The thinner the projectile with respect to the explosive, the smaller the tensile stress. If the explosive is initiated with a plane wave lens, the tensile stress is lower than for initiation with multiple detonators over a plane. The previous plane wave lens designs did however induce a tensile stress close to the spall strength of the projectile. The tensile stress can be reduced by changes in the component thicknesses. Experiments to verify the operation of explosively-launched projectiles should attempt to measure porosity induced in the projectile: arrival time measurements may be insensitive to porous regions caused by damaged or recollected material

Non-Iterative Characteristics Analysis for High-Pressure Ramp Loading

In the canonical ramp compression experiment, a smoothly-increasing load is applied to the surface of the sample, and the particle velocity history is measured at two or more different distances into the sample, at interfaces where the surface of the sample can be probed. The velocity histories are used to deduce a stress-density relation, usually using iterative Lagrangian analysis to account for the perturbing effect of the impedance mismatch at the interface. In that technique, a stress- density relation is assumed in order to correct for the perturbation, and is adjusted until it becomes consistent with the deduced stress-density relation. This process is subject to the usual difficulties of nonlinear optimization, such as the existence of local minima (sensitivity to the initial guess), possible failure to converge, and relatively large computational effort. We show that, by considering the interaction of successive characteristics reaching the interfaces, the stress-density relation can be deduced directly by recursion rather than iteration. This calculation is orders of magnitude faster than iterative analysis, and does not require an initial guess. Direct recursion may be less suitable for very noisy data, but it was robust when applied to trial data. The stress-density relation deduced was identical to the result from iterative Lagrangian analysis

Preliminary checklist of the Cerambycidae, Disteniidae, and Vesperidae (Coleoptera) of Peru

A preliminary checklist of the Cerambycidae, Disteniidae, and Vesperidae (Coleoptera) of Peru is presented. Within Cerambycidae, we record five subfamilies, 55 tribes, 345 genera and subgenera, and 714 species. Within Disteniidae, we record one tribe, six genera, and 11 species. We also record one subfamily, one tribe, one genus, and two species within Vesperidae. Four new country records are recorded: one species in the tribe Anacolini (Cerambycidae: Prioninae): Cycloprionus flavus Tippmann, 1953; and three species in the tribe Onciderini (Cerambycidae: Lamiinae): Cacostola simplex (Pascoe, 1859); Marensis simplex (Bates, 1865); Trachysomus cavigibba Martins, 1975. In addition, 161 species recorded are known only from Peru

Active Listening by Hospital Chaplaincy Volunteers: Benefits, Challenges and Good Practice

Active listening (AL) is a communication technique frequently used in counselling. This study explored the feasibility of implementing a ward-based AL intervention for patients by chaplaincy volunteers in the UK National Health Service. Seven focus groups (n=47) included healthcare researchers, lecturers, nurses, patients, AL tutors, active listeners volunteers and chaplaincy volunteers. Acceptability and perceived effectiveness of a patient/volunteer listener intervention were explored. Analysis followed the framework approach. Four themes emerged: (a) Listening as a wellbeing generator; (b) Benefits of AL delivered by volunteers; (c) Spirituality and public perceptions of hospital chaplaincy; (d) Challenges of structured communication techniques in acute care. Participants reported positive attitudes towards the introduction of AL provided by volunteers in acute wards. They shared a common belief that when people are listened to, wellbeing improves through control, choice and empowerment. Patients’ acceptability of the intervention increased if it was delivered by volunteers

Renormalization Group Method and Reductive Perturbation Method

It is shown that the renormalization group method does not necessarily eliminate all secular terms in perturbation series to partial differential equations and a functional subspace of renormalizable secular solutions corresponds to a choice of scales of independent variables in the reductive perturbation method.Comment: 5 pages, late

Derivation of Amplitude Equations by Renormalization Group Method

A proper formulation in the perturbative renormalization group method is presented to deduce amplitude equations. The formulation makes it possible not only avoiding a serious difficulty in the previous reduction to amplitude equations by eliminating all of the secular terms but also consistent derivation of higher-order correction to amplitude equations.Comment: 6 page, revte

Holding back the tears: individual differences in adult crying proneness reflect attachment orientation and attitudes to crying

Despite being a universal human attachment behavior, little is known about individual differences in crying. To facilitate such examination we first recommend shortened versions of the attitudes and proneness sections of the Adult Crying Inventory using two independent samples. Importantly, we examine attachment orientation differences in crying proneness and test the mediating role of attitudes toward crying in this relationship. Participants (Sample 1 N=623, Sample 2 N=781), completed online measures of adult attachment dimensions (avoidance and anxiety), attitudes towards crying, and crying proneness. Exploratory factor analyses in Sample 1 revealed four factors for crying attitudes: crying helps one feel better; crying is healthy; hatred of crying; and crying is controllable; and three factors for crying proneness: threat to self; sadness; and joy. Confirmatory factor analyses in Sample 2 replicated these structures. Theoretically and statistically justified short forms of each scale were created. Multiple mediation analyses revealed similar patterns of results across the two samples, with the attitudes ‘crying is healthy’ and ‘crying is controllable’ consistently mediating the positive links between attachment anxiety and crying proneness, and the negative links between attachment avoidance and crying proneness. Results are discussed in relation to attachment and emotion regulation literature