The immunes and principles of the Roman army

This thesis discusses the two groups of officers found, in every branch of the Roman Army in both Rome and the provinces below the rank of centurion, the immunes and principales. The immunes were soldiers exempted from fatigues in return for carrying out special duties and the principales were soldiers who received extra pay in connection with their higher rank. The principales were the nearest equivalent in the Roman Army of the modem non-commissioned officer. The period covered is from Augustus to Diocletian, In Volume I, following the introduction and a discussion of the nature of the available evidence, the career structure of these officers in each branch of the army is analysied. Special attention is paid to the duration of the career, the promotion prospects of the soldiers and the chronological development of the career structure, tracing its growth from the Republic onwards, its developed state in the second century and the changes in the third century resulting from the increased dichotomy between the fighting and the clerical branches of the army. The known careers of individual soldiers in the army are also examined in detail. In Volume II each post in the army is investigated in turn. An attempt is made to determine the number of soldiers holding each post, the history of the post is discussed, and wherever possible its relative status determined, its position in the career structure analysised and the promotion prospects of its holders considered

The Antonine Wall: the current state of knowledge

No abstract available

Lawrence Keppie: an appreciation

No abstract available

The Antonine Wall: the current state of knowledge

No abstract available

Researching DIY Cultures: Towards a Situated Ethical Practice for Activist-Academia

The empirical study of DIY culture and feminist cultural activism is a flourishing interdisciplinary research area particularly in the USA, Canada, Australia and UK. This has enabled a growth in participant-researchers doing research on their own DIY cultures and activist communities of belonging. Tensions occur here for the participant-researcher in relation to conventional data collection methods, ethical and moral decisions and modes of research dissemination. This article develops discussions of dilemmas experienced by the authors during doctoral research projects on DIY punk, roller derby and queer feminist music cultures. We detail the possibilities and tensions met when the participant-researcher encounters existing subcultural theories, ethical codes of practice, data collection methods and the dissemination of academic research. In addition we offer insights into the under-documented emotional impacts and moments of crisis the participant-researcher needs to attend to when carrying out research with/in personal and political communities of belonging. In conclusion, we offer a series of recommendations for a situated ethical practice for research with/in DIY cultures in relation to engaged data generation

Magnon-photon coupling in the noncollinear magnetic insulator Cu 2 OSeO 3

Anticrossing behavior between magnons in the noncollinear chiral magnet Cu2OSeO3 and a two-mode X-band microwave resonator was studied in the temperature range 5–100 K. In the field-induced ferrimagnetic phase, we observed a strong-coupling regime between magnons and two microwave cavity modes with a cooperativity reaching 3600. In the conical phase, cavity modes are dispersively coupled to a fundamental helimagnon mode, and we demonstrate that the magnetic phase diagram of Cu2OSeO3 can be reconstructed from the measurements of the cavity resonance frequency. In the helical phase, a hybridized state of a higher-order helimagnon mode and a cavity mode—a helimagnon polariton—was found. Our results reveal a class of magnetic systems where strong coupling of microwave photons to nontrivial spin textures can be observed

Continuous-wave room-temperature diamond maser

The maser, older sibling of the laser, has been confined to relative obscurity due to its reliance on cryogenic refrigeration and high-vacuum systems. Despite this it has found application in deep-space communications and radio astronomy due to its unparalleled performance as a low-noise amplifier and oscillator. The recent demonstration of a room-temperature solid- state maser exploiting photo-excited triplet states in organic pentacene molecules paves the way for a new class of maser that could find applications in medicine, security and sensing, taking advantage of its sensitivity and low noise. However, to date, only pulsed operation has been observed in this system. Furthermore, organic maser molecules have poor thermal and mechanical properties, and their triplet sub-level decay rates make continuous emission challenging: alternative materials are therefore required. Therefore, inorganic materials containing spin-defects such as diamond and silicon carbide have been proposed. Here we report a continuous-wave (CW) room-temperature maser oscillator using optically pumped charged nitrogen-vacancy (NV) defect centres in diamond. This demonstration unlocks the potential of room-temperature solid-state masers for use in a new generation of microwave devices.Comment: 7 pages, 4 figure

Gelatine backing affects the performance of single-layer ballistic-resistant materials against blast fragments

Penetrating trauma by energized fragments is the most common injury from explosive devices, the main threat in the contemporary battlefield. Such devices produce projectiles dependent upon their design, including preformed fragments, casings, glass, or stones; these are subsequently energized to high velocities and cause serious injuries to the body. Current body armor focuses on the essential coverage, which is mainly the thoracic and abdominal area, and can be heavy and cumbersome. In addition, there may be coverage gaps that can benefit from the additional protection provided by one or more layers of lightweight ballistic fabrics. This study assessed the performance of single layers of commercially available ballistic protective fabrics such as Kevlar®, Twaron®, and Dyneema®, in both woven and knitted configurations. Experiments were carried out using a custom-built gas-gun system, with a 0.78-g cylindrical steel fragment simulating projectile (FSP) as the impactor, and ballistic gelatine as the backing material. FSP velocity at 50% risk of material perforation, gelatine penetration, and high-risk wounding to soft tissue, as well as the depth of penetration (DoP) against impact velocity and the normalized energy absorption were used as metrics to rank the performance of the materials tested. Additional tests were performed to investigate the effect of not including a soft-tissue simulant backing material on the performance of the fabrics. The results show that a thin layer of ballistic material may offer meaningful protection against the penetration of this FSP. Additionally, it is essential to ensure a biofidelic boundary condition as the protective efficacy of fabrics was markedly altered by a gelatine backing