Improving the performance of swift-water rescue quick release harnesses

This paper considered the effectiveness of empathic design modifications to quick release harness design. It was found that the critical element in effecting a rapid and efficient release was the tape length distal to the buckle/back-bar components. We have concluded that the length of tape pulled through the buckle and the loading of the buckle/ tri-glide are critical to ensure an effective release. Physical separation of tape and buckle mechanism when the harness is released is crucial to the effective release. We then considered the problems this may pose in multiple user situations such as ‘call out’ teams or training use and we propose that the adaptation utilised in the research harness to facilitate testing may provide a simple and low cost solution to the multiple user problem allowing easy adjustment of the harness to ensure the separation of buckle and tape on release. We conclude by outlining the design adaptations and recommendations for the training and use of the quick release harness and make recommendations for the training of QRH use

A high-speed integrated circuit with applications to RSA Cryptography

Merged with duplicate record 10026.1/833 on 01.02.2017 by CS (TIS)The rapid growth in the use of computers and networks in government, commercial and private communications systems has led to an increasing need for these systems to be secure against unauthorised access and eavesdropping. To this end, modern computer security systems employ public-key ciphers, of which probably the most well known is the RSA ciphersystem, to provide both secrecy and authentication facilities. The basic RSA cryptographic operation is a modular exponentiation where the modulus and exponent are integers typically greater than 500 bits long. Therefore, to obtain reasonable encryption rates using the RSA cipher requires that it be implemented in hardware. This thesis presents the design of a high-performance VLSI device, called the WHiSpER chip, that can perform the modular exponentiations required by the RSA cryptosystem for moduli and exponents up to 506 bits long. The design has an expected throughput in excess of 64kbit/s making it attractive for use both as a general RSA processor within the security function provider of a security system, and for direct use on moderate-speed public communication networks such as ISDN. The thesis investigates the low-level techniques used for implementing high-speed arithmetic hardware in general, and reviews the methods used by designers of existing modular multiplication/exponentiation circuits with respect to circuit speed and efficiency. A new modular multiplication algorithm, MMDDAMMM, based on Montgomery arithmetic, together with an efficient multiplier architecture, are proposed that remove the speed bottleneck of previous designs. Finally, the implementation of the new algorithm and architecture within the WHiSpER chip is detailed, along with a discussion of the application of the chip to ciphering and key generation

Raft on a highline: Loads and trim

This study examines the loads associated with the positioning of a 4.5m raft on a high line in moving water. Testing was conducted within a flow-calibrated channel demonstrating representative stream velocities typical (0.6 – 5.4ms/ also MPH) of those encountered during water related rescues. The raft was positioned from a high line mid-stream, and a load cell was utilised to collect force/time data. The independent variables of trim (relative positioning of the load within the boat) and average stream velocity were investigated. The findings challenge assumptions regarding the impact of trim on the loads within a highline, the relationship between flow rate and loads on highline and make recommendation for training and practice. The study contributes to understanding the loads placed on high lines by representative rafts during operational rescues

Highline Rescue Boat Systems: A study of the load created by tethered rescue boats with respect to stream velocity, trim and hull size.

Water rescue practitioners must balance the degree of risk associated with a given technique with the needs of the victim. One such technique, the focus of this study, consists of a rescue boat positioned within moving water by means of a high line. It has been shown to be useful for high risk rescues, often when the patient or subject is unable to assist with their own rescue. Despite the degree of risk, little empirical data pertaining to the resulting load (force) placed on the highline by a boat in moving water can be identified in the literature. In the absence of contextual data, this study examines the research undertaken by the rope rescue community into the forces exerted by suspended loads, and argues that many of the resulting principles, especially the establishment of the load, are not applied during highline positioned boat operations. Therefore the research question of this thesis; ‘what force (N) will be induced by a boat positioned from a high line when deployed in moving water typically encountered during swift water rescue?’ is addressed by establishing the load under real-world operational conditions. In addition to this, the antecedents leading to a proposed worst case event (WCE) are also presented, and tested. Testing was conducted within a flow-calibrated channel offering stream velocities typical of those encountered during water related rescues. Two contrasting craft were selected for the investigation as representative of those used during swiftwater rescues, a Eurocraft (large hull) and an MFC Rescue Sled (small hull). The experiment subjected the high line to a range of forces induced by the two craft over a range of stream velocities between 0.6 – 5.4ms-1. A load cell was utilised to collect force/time data during deployments to the current vector. The independent variables of trim (relative positioning of the load within the boat) and average stream velocity were investigated. Under low flow conditions, when trimmed neutrally (the crew were positioned centrally), the Eurocraft induced the highest force on the high line (approximately 1.22kN at 0.6 ms-1 average stream velocity). When trimmed with the load placed to the rear (aft) or towards the front of the boat (bow trim) force was reduced on the high line. Conversely at higher stream velocities (4.5 – 5.4 ms-1) force values rose rapidly when bow or aft trim conditions were induced, and force was reduced in a neutral trim state. The testing of the WCE induced a peak force of 3.42kN when the boat was deliberately flooded with water during the highest flow available (5.4 ms-1). The force associated with the WCE for a high line constructed with a track line mid-point angle tending to >120º is a theoretical force multiplication approaching that of the rating of the equipment

Endogenous retroviral elements in the canine genome

Defective endogenous retroviral elements have recently been found in a canine lymphosarcoma (LSA) cell line and we have characterized these by DNA sequencing. This study was designed to determine if similar elements are present in naturally-occurring canine LSAs or in normal canine DNA. Two probes were prepared by sub-cloning sequences from the 5' and 3' ends of the canine endogenous retroviralpol gene. Probes were chosen from areas sharing at least 60% homology and complete colinearity with AKV murine leukemia virus. High molecular weight genomic DNA was prepared from a variety of canine tissues: 12 samples were from LSA lymph nodes, 2 from lymphoblasts in cases of acute lymphoblastic leukemia and 7 from normal kidney. Genomic DNA was digested with restriction endonucleases and fragments were separated by agarose gel electrophoresis. Southern transfer and hybridization under stringent conditions with the canine retroviral probes revealed numerous retroviral bands. The pattern of bands was identical for all tissues examined. Similar treatment of DNA from the original LSA cell Line from which the probes were derived produced an identical pattern of bands. In summary, canine DNA has been shown to contain multiple copies of endogenous retroviral elements. No difference in the pattern of proviral bands has been observed between normal and LSA tissues, so no etiological significance can yet be ascribed to these elements. Further studies are in progress to determine whether any of these elements erpress themselves at the RNA or protein level

Phase-field approach to heterogeneous nucleation

We consider the problem of heterogeneous nucleation and growth. The system is described by a phase field model in which the temperature is included through thermal noise. We show that this phase field approach is suitable to describe homogeneous as well as heterogeneous nucleation starting from several general hypotheses. Thus we can investigate the influence of grain boundaries, localized impurities, or any general kind of imperfections in a systematic way. We also put forward the applicability of our model to study other physical situations such as island formation, amorphous crystallization, or recrystallization.Comment: 8 pages including 7 figures. Accepted for publication in Physical Review

Streams Going Notts: The tidal debris finder comparison project

While various codes exist to systematically and robustly find haloes and subhaloes in cosmological simulations (Knebe et al., 2011, Onions et al., 2012), this is the first work to introduce and rigorously test codes that find tidal debris (streams and other unbound substructure) in fully cosmological simulations of structure formation. We use one tracking and three non-tracking codes to identify substructure (bound and unbound) in a Milky Way type simulation from the Aquarius suite (Springel et al., 2008) and post-process their output with a common pipeline to determine the properties of these substructures in a uniform way. By using output from a fully cosmological simulation, we also take a step beyond previous studies of tidal debris that have used simple toy models. We find that both tracking and non-tracking codes agree well on the identification of subhaloes and more importantly, the {\em unbound tidal features} associated with them. The distributions of basic properties of the total substructure distribution (mass, velocity dispersion, position) are recovered with a scatter of $\sim20$. Using the tracking code as our reference, we show that the non-tracking codes identify complex tidal debris with purities of $\sim40$. Analysing the results of the substructure finders, we find that the general distribution of {\em substructures} differ significantly from the distribution of bound {\em subhaloes}. Most importantly, both bound and unbound {\em substructures} together constitute $\sim18$ of the host halo mass, which is a factor of $\sim2$ higher than the fraction in self-bound {\em subhaloes}. However, this result is restricted by the remaining challenge to cleanly define when an unbound structure has become part of the host halo. Nevertheless, the more general substructure distribution provides a more complete picture of a halo's accretion history.Comment: 19 pages, 12 figures, accepted for publication in MNRA

Manual feeding device experiences of people with a neurodisability

Neurological bilateral upper limb weakness can result in self-feeding difficulties and reliance on carers. Mealtimes become time consuming and frustrating. This exploratory inquiry examined the experiences, of users of a feeding device. Method: Semi-structured interviews were conducted either by telephone or administered via email to explore quality of life, changes to independence, benefits/limitations, and psychological impact of the equipment. Findings: Thematic analysis gave rise to five themes: Independence, emotions, impact on life, motivation and limitations. Conclusion: This exploratory inquiry has contributed new qualitative evidence to the knowledge and understanding of users' experiences of a manual feeding device. Users report that the need for assistance/support is reduced and their quality of life, independence and freedom improved. Time and resources savings for the family, carers and staff appear to result in a more equal relationship between user and carer