Beyond Power over Ethernet : the development of Digital Energy Networks for buildings

Alternating current power distribution using analogue control and safety devices has been the dominant process of power distribution within our buildings since the electricity industry began in the late 19th century. However, with advances in digital technology, the seeds of change have been growing over the last decade. Now, with the simultaneous dramatic fall in power requirements of digital devices and corresponding rise in capability of Power over Ethernet, an entire desktop environment can be powered by a single direct current (dc) Ethernet cable. Going beyond this, it will soon be possible to power entire office buildings using dc networks. This means the logic of “one-size fits all” from the existing ac system is no longer relevant and instead there is an opportunity to redesign the power topology to be appropriate for different applications, devices and end-users throughout the building. This paper proposes a 3-tier classification system for the topology of direct current microgrids in commercial buildings – called a Digital Energy Network or DEN. The first tier is power distribution at a full building level (otherwise known as the microgrid); the second tier is power distribution at a room level (the nanogrid); and the third tier is power distribution at a desktop or appliance level (the picogrid). An important aspect of this classification system is how the design focus changes for each grid. For example; a key driver of the picogrid is the usability of the network – high data rates, and low power requirements; however, in the microgrid, the main driver is high power and efficiency at low cost

A novel DSM philosophy for building integrated renewable systems

This paper presents an overview of a novel concept in IT network design and power control focused on matching building integrated renewable power generation with local demands. It describes how this is achieved through combination of energy demand reduction and dynamic utilisation of embedded energy storage in a robust, efficient and cost effective manner. A brief overview of the main features of the design is given in terms of its intended benefits as an integrated system. The load components and distribution topology are described for this experimental system within the limits set by the capacity, capabilities and desired function of the network. Power supply to the network is described as including a back-up source to the photovoltaic (PV) source to add functionality and stability with no requirements for undesirable exporting of excess PV generation. The necessary configuration of the renewable array integrating with the network is also highlighted with an example compatible solar module device. A trial of the technology and demand management control in a high profile office building is described. This trial in a live working environment is providing invaluable real world data to compare against modelling and network simulation results

Urban grasslands support threatened water voles

Urbanisation is often linked with habitat loss and a reduction in species richness but some species may be able to adapt to urban environments. Water voles Arvicola amphibius, a rapidly declining species in the UK, have recently been recorded in isolated grassland habitats in Glasgow, Scotland’s largest city (human population 1.2 million). The aim of this study was to determine the distribution and habitat characteristics of water vole populations occupying these dry grasslands. Field work was undertaken from March to October 2014 in a 34 km2 study area located 3 km east of the city centre. Field sign transects recorded water vole presence in 21/65 (32%) and 19/62 (31%) surveyed sites in spring and autumn, respectively. Vole occupancy increased with distance from water and was greatest in parkland, followed by sites with rank vegetation and roadside habitats. Occupancy was lower where signs of predators were recorded but surprisingly occupancy was found to be greater in the most disturbed sites, perhaps linked to the fact that many of these sites were public parks containing suitable grassland. Sites occupied by water voles were classed as neutral grasslands with species composition dominated by two main species. The number of grassland sites occupied by water voles, especially within public areas suggests that careful management of these urban grassland habitats will benefit the conservation of this highly threatened species in the UK

Risk based testing for Mycobacterium bovis following a clinical case in a zoological garden

This document is the version of a published work that appeared in final form in Journal of Zoo and Aquarium Research. To access the final edited and published work see http://dx.doi.org/10.19227/jzar.v2i1.62Mycobacterium bovis is a strictly controlled disease. Outbreaks in zoos result in animal movement bans, disease investigation and euthanasia of infected animals. Both specific tuberculosis legislation and European Directive 92/65, often known as the "Balai" directive, require zoos to be free from tuberculosis in order to import and export animals. This paper describes the use of a risk based targeted testing programme for tuberculosis following a confirmed case of disease. This regime ensured a comprehensive but proportionate disease investigation developed through close co-operation with government veterinary officials, therefore limiting the impact of anaesthetic procedures and animal handling required to complete the necessary testing

Stochastic Optimization of Power System Dynamics for Grid Resilience

When faced with uncertainty regarding potential failure contingencies, prioritizing system resiliency through optimal control of exciter reference voltage and mechanical torque can be arduous due to the scope of potential failure contingencies. Optimal control schemes can be generated through a two-stage stochastic optimization model by anticipating a set of contingencies with associated probabilities of occurrence, followed by the optimal recourse action once the contingency has been realized. The first stage, common across all contingency scenarios, co-optimally positions the grid for the set of possible contingencies. The second stage dynamically assesses the impact of each contingency and allows for emergency control response. By unifying the optimal control scheme prior and post the failure contingency, a singular policy can be constructed to maximize system resiliency

Using Social Media in Schools

Social media is becoming more eminently woven into the sociocultural fabric of global societies in the 21st century. From emerging platforms and ever-evolving multimodal features, to algorithmic changes and privacy concerns, social media is indubitably shaping the frontier of how people communicate, interact, and perceive the world around them. Using social media in schools is, of course, not a new phenomenon. However, given unabating advances in digital technology coupled with shifting user demands, social media is constantly in flux. Thus, staying abreast of social media trends and uses in the field of education is a critical endeavor and merits on-going conversations

Planting depth and within-field soil variability impacts on corn stand establishment and yield

Seedbed conditions during corn (Zea mays L.) planting can have substantial impact on corn stand establishment and final yield. Planting management decisions are complex due to spatial variability caused by changing soil characteristics such as soil texture or landscape position. Field experiments conducted in central Missouri from 2017 to 2019 assessed the effects of varying corn planting depths on stand establishment and yield. Sites included fine- and coarse-textured alluvial soils, and summit, back, and foot slope positions of Alfisol claypan soil landscapes. On alluvial soil, deep planting (7.6 cm) often had the most uniform and timely emergence. Shallow planting (3.8 cm) had the least uniform emergence and was particularly troublesome on fine-textured soil under warm conditions. Under these conditions, grain yield for one site-year was 2.8 Mg ha–1 less when planting shallow compared with planting deep. On the claypan landscape position study, stand establishment was affected by both warm and cool growing conditions during the emergence period. During warm conditions, deep planting enhanced emergence uniformity and rate (1.1 d less to reach 90% emergence than shallow planting); the opposite was true for cool conditions (3.7 d more). Yield was not affected by planting depth at any of the site-years of the landscape position study. These results indicate that certain soil textures and landscape positions require greater attention to planting depth to achieve optimum stand establishment. Differences could be used in on-the-go planter prescriptions. These findings also demonstrate that despite early establishment differences, stands can often compensate and maintain similar yield