Search

Transport is something we all use. Even in the digital age, we all need transport to connect with family, enjoy leisure, get to work, and to meet friends. Even if we never left the house we would still use transport indirectly, as we take deliveries from local shops or goods are transported from further afield. While big-picture concepts like climate change and decarbonisation can feel remote or overwhelming, this journal shows how decarbonisation is possible and how we can all take action to make a difference. We explore both the challenge and possibility of decarbonisation in Cumbria, examining: • Where we are now • What happens if we carry on as we are • How we need to rethink our values if we are to address decarbonisation • Potential decarbonised futures • What we can do to shape desirable futures This compact collection of ideas draws on evidence from over 80 researchers, policymakers, community organisations and local businesses who attended a Decarbon8 event in Cumbria on 22nd - 23rd November 2022. It was created during a 6 hour ‘Instant Journal Design Sprint’ facilitated by Nifty Fox Creative, to show what can be achieved when all the right people are in the right room at the right time. We can act both together and individually to take on the challenge of decarbonisation and make a better future!

Key to the development of cost effective integrated components is low cost, low power circuitry capable of being repurposed from providing manufacturing based functions, such as characterisation and calibration, to operational control functions. Although these individual functions are well known, efficient and low cost implementations are required to enable competitive module pricing. In the case of an optical Mach Zehnder Modulator (MZM), bias currents require complex control functions, for example based around digitally synthesized sinusoidal pilot tones and harmonic detection via filters [1][2]. Control methods making use of calibrated laboratory equipment have been proposed [2], whereas here we consider the practical adoption of these methods with low cost and low power components which could be readily integrated into an optical module. In particular we investigate the behaviour and capabilities required for automatic digital bias control functionality implemented in a small gate count, low cost Field Programmable Gate Array (FPGA) when used in conjunction with a MZM. We assess the suitability of highly efficient implementations of DSP functions within the bias controller, such as digital filters, for example investigating the use of a computationally efficient algorithm for computing a single component of a discrete Fourier transform [3], and demonstrate the viability of using low cost digital hardware to implement a circuit capable of monitoring the MZM transfer function. The concept of creating cost effective, repurposable hardware is crucial for implementation and inclusion in optical devices deployed in communications networks and beyond.

Electrically-assisted cycling can make a major contribution to sustainable mobility. For some people, hills are a barrier for cycling. This paper focuses on how and why electrically-assisted bikes make a difference to cycling in hilly contexts, and can thus be an important element of sustainable mobility in hilly geographies. It makes a novel contribution in being able to draw on recorded sensor data of the actual use of assistance in relation to the specific geography of the route cycled (GPS data), and interview/survey material. It shows that e-bikes extend the range, nature and scope of journeys manageable by bike, and therefore the general viability of e-bikes as alternative to other modes. It highlights that the benefits of using e-bikes are often also psychological, since they can change the overall enjoyability of the cycling experience in hilly areas. Resulting policy recommendations, that could lead to significant CO2 savings through the uptake of e-cycling in hilly contexts, include ‘try before you buy’ schemes, training for e-bike users and investing in relevant cycling infrastructure.

In high-motorisation, car-dependent countries, transport affordability is intimately linked to the price of oil derived motor fuels, which may become increasingly volatile in the future due to global oil price movements and environmental taxation. The negative impacts of fuel price spikes in terms of increased household expenditure and economic stress are unevenly spatially and socially distributed. Previous research has found that vulnerability to fuel price increases is higher in peripheral, peri-urban and rural areas, and that low income tends to be co-located with high car dependence and low vehicle fuel efficiency, with a compounding effect on vulnerability. The goal of this article is to test these hypotheses for England, providing new evidence on spatial patterns of vulnerability to fuel price increases at the small-area level. We propose a composite vulnerability indicator combining data on income, accessibility, vehicle inspection and vehicle registration for 2011. Within English city-regions, we find little evidence of the socially regressive patterns previously identified in the literature. This is explained by the persistent concentration of poverty in urban cores, as well as by the poor fuel economy of the vehicle fleet in wealthier areas, due to the prevalence of powerful vehicles there. On the other hand, our analysis suggests that the impacts of fuel price increases would be very unequal between city-regions, as the least sensitive metropolitan area (Greater London) is also characterised by high levels of adaptive capacity. We conclude by setting out an agenda for future research on spatial vulnerability to fuel price increases.

In this paper, gain, noise and nonlinear performance characterization of cascaded broadband discrete Raman amplifiers with different gain fibre combinations is presented. We numerically demonstrate the design of a backward-pumped cascaded dual stage broadband (∼70 nm) discrete Raman amplifier with high gain (∼19 dB), low noise (∼ 6 dB noise figure) and lower nonlinear penalty by optimizing two different types of gain fibres.

Unrepeatered 100 Gbit/s per channel wave-divisionmultiplexed dual-polarization-QPSK transmission with random distributed feedback fiber laser-based Raman amplification using fiber Bragg grating is demonstrated. Transmission of 1.4 Tb/s (14 × 100 Gbit/s) was possible in 352.8 km link and 2.2 Tb/s (22 × 100 Gbit/s) was achieved in 327.6 km without employing remote optically pumped amplifier or speciality fibers.