Improving the thermal performance of single-glazed windows using translucent granular aerogel

Copyright @ 2011 Taylor & FrancisCost-effective materials, products and installation methods are required to improve the energy efficiency of the UK's existing building stock. The aim of this paper is to assess the potential for high-performance translucent granular aerogel insulation to be retrofitted over single glazing to reduce heat loss without blocking out all of the useful natural light. In situ testing of a 10-mm-thick prototype panel, consisting of a clear twin-wall polycarbonate sheet filled with granular aerogel, was carried out and validated with steady-state calculations. Results demonstrate that an 80% reduction in heat loss can be achieved without detrimental reductions in light transmission. Payback calculations accounting for the inevitable thermal bridging from openable solutions such as roller shutters or pop-in secondary glazing suggest that a return on investment between 3.5 and 9.5 years is possible if products are consistently used over the heating season. Granular aerogel is a promising material for improving the thermal performance of existing windows. Future research will seek to map out different ways in which the material can be applied to the existing UK housing stock, identifying which systems offer the greatest potential for widespread CO2 savings over their life cycle.This work is funded by the EPSRC, Brunel University and Buro Happold Ltd

Exploring the parameter space of texture 4 zero quark mass matrices

We have attempted to extend the parameter space of the elements of the texture 4 zero Hermitian quark mass matrices, to include the case of `weak hierarchy' amongst them along with the usually considered `strong hierarchy' case. This has been carried out by giving wide variation to the hierarchy defining parameters D_U and D_D, having implications for the structural features of the mass matrices. We find that not only the weakly hierarchical mass matrices are able to reproduce the strongly hierarchical mixing angles but also both the phases having their origin in the mass matrices have to be non zero to achieve compatibility of these matrices with recent quark mixing data. Further noting the difference between the exclusive and inclusive values of V_ub, we have carried out separate analyses corresponding to these.Comment: 13 pages, 4 figures, version accepted for publication in Journal Of Physics

An extensive and autonomous deep space navigation system using radio pulsars

Interstellar navigation poses significant challenges in all aspects of a spacecraft. One of them is reliable, low-cost, real-time navigation, especially when there is a considerable distance between Earth and the spacecraft in question. In this paper, a complete system for navigation using pulsar radio emissions is described and analysed. The system uses a pulsar‟s emissions in the radio spectrum to create a novel system capable of fully autonomous navigation. The system is roughly divided into two parts, the front - end and the back - end, as well as their subdivisions. The front - end performs initial signal reception and pre-processing. It applies time-based coherent de-dispersion to allow for low-power on-board processing, and uses a very wide bandwidth to limit the required antenna size. As a result, the electronics required performing the processing is complex, but the system is well limited in both size and power consumption

Psychological and Criminological Understanding of Terrorism: Theories and Models

Terrorism studies began as a niche area of enquiry in the early 1970s within history, political science and sociology. Terrorism studies, as a whole, is becoming increasingly more empirically and quantitatively oriented after years of questionable data and science. Multiple papers have attempted to use psychoanalytical theories to explain the cause of terrorist behaviour. A. Kaplan wrote that terrorism is a response to poor self-esteem, used by an individual to counter impulses of self-contempt. Few studies have empirically tested traditional criminological theories such as anomie, strain, disorganization, or control approaches in a terrorism context. Traditional criminology seeks to identify and explain why individuals engage in criminal activity, with a focus on sociological, psychological and developmental perspectives. The rational choice perspective has been useful in understanding political violence including terrorism and literature consistently supports the presumption that terrorists are rational actors

One‐Step Process for Press Hardened Steel–Carbon Fiber Reinforced Thermoset Polymer Hybrid Parts

A new one‐step process for manufacturing press hardened steel–carbon fiber reinforced (thermoset) polymer hybrid parts with potential for reduced cycle time, infrastructure requirements, and energy consumption compared with traditional two‐ and three‐step processes is developed. The process combines and optimizes the press hardening and prepreg compression molding technologies, traditionally used in isolation for manufacturing press hardened steel and carbon fiber reinforced polymer parts, respectively, to produce hybrid parts in a one‐step, fully integrated process. Heat required for curing and bonding prepreg to steel is provided by residual heat of the steel part immediately following hot forming and interrupted die‐quenching of steel. Thermal conductivity of tool material is investigated to achieve the optimal balance between die‐quenching rate for martensite formation in steel and temperature maintenance for complete curing and bonding of prepreg. Addition of epoxy adhesive and thickness ratio between steel and prepreg are also investigated. Benchmarking is conducted against parts manufactured by the traditional two‐step process, in which the press hardened steel part is formed in isolation before joining with the carbon fiber reinforced polymer part. No sacrifice of part quality is found from the new one‐step process with no loss of mechanical performance, despite clear economic and environmental advantages

Spatial Decision Making of Terrorist Target Selection: Introducing the TRACK Framework

Guided by previous research and recent empirical analyses, this paper gives insight into elements that characterize the spatial decision making of terrorist target selection. Five key factors explain why targets are chosen by terrorists. The authors propose that, generally, targets will be selected when they are Tolerable, Relevant, Accessible, Close and/or Known. This is followed by a discussion of attacks witnessed between January 2013 and December 2018 in the United Kingdom, and implications

Lone Actor Terrorists: A Residence-to-Crime Approach

Although there has recently been a considerable increase in research into lone actor terrorism, one of the main areas that remains understudied is that of target selection. The lack of empirically driven studies that can guide prevention measures is a notable oversight. This paper applies methods from environmental criminology to examine the residence-to-attack journeys of 122 lone terrorist acts in the U.S and Europe. The distance decay effect was evident, and significant differences were found between subgroups. Individuals were more likely to travel further if a) they were in the U.S, b) they had links to a wider network, c) they had a single-issue ideology, d) they attacked an iconic target, e) they attacked a symbolic building, or f) they used a bomb as their main weapon. A few case studies are discussed which highlight a need to conduct further research that considers the whole nodal network of an individual. The findings suggest that distance can be put forward as a constraining factor on lone actor target selection and provide support for the notion that the spatial decision making of terrorists is similar to traditional criminals

A Biological Rationale for Musical Scales

Scales are collections of tones that divide octaves into specific intervals used to create music. Since humans can distinguish about 240 different pitches over an octave in the mid-range of hearing [1], in principle a very large number of tone combinations could have been used for this purpose. Nonetheless, compositions in Western classical, folk and popular music as well as in many other musical traditions are based on a relatively small number of scales that typically comprise only five to seven tones [2]–[6]. Why humans employ only a few of the enormous number of possible tone combinations to create music is not known. Here we show that the component intervals of the most widely used scales throughout history and across cultures are those with the greatest overall spectral similarity to a harmonic series. These findings suggest that humans prefer tone combinations that reflect the spectral characteristics of conspecific vocalizations. The analysis also highlights the spectral similarity among the scales used by different cultures

Becoming 'ward smart' medical students.

BACKGROUND: A small number of medical students elect to work as health care assistants (HCAs) during or prior to their undergraduate training. There is a significant body of evidence in the literature regarding the impact of HCA experience on student nurses; however, little research has examined the effects of such experience on medical students. METHODS: All fourth-year medical students with self-declared experience as HCAs from a single UK medical school were invited to participate in focus groups to explore their experiences and perceptions. Ten students from the year group took part. RESULTS: Participants felt that their experience as HCAs enhanced their learning in the workplace through becoming 'ward smart', helping them to become socialised into the world of health care, providing early meaningful and humanised patient interaction, and increasing their understanding of multidisciplinary team (MDT) members' roles. Little research has examined the effects of [HCA] experience on medical students DISCUSSION: Becoming 'ward smart' and developing a sense of belonging are central to maximising learning in, from and through work on the ward. Experience as a HCA provides a range of learning and social opportunities for medical students, and legitimises their participation within clinical communities. HCA experience also seems to benefit in the 'hard to reach' dimensions of medical training: empathy; humanisation of patient care; professional socialisation; and providing a sense of belonging within health care environments