Microgrids & District Energy: Pathways To Sustainable Urban Development

A microgrid is an energy system specifically designed to meet some of the energy needs of a group of buildings, a campus, or an entire community. It can include local facilities that generate electricity, heating, and/or cooling; store energy; distribute the energy generated; and manage energy consumption intelligently and in real time. Microgrids enable economies of scale that facilitate local production of energy in ways that can advance cost reduction, sustainability, economic development, and resilience goals. As they often involve multiple stakeholders, and may encompass numerous distinct property boundaries, municipal involvement is often a key factor for successful implementation. This report provides an introduction to microgrid concepts, identifies the benefits and most common road blocks to implementation, and discusses proactive steps municipalities can take to advance economically viable and environmentally superior microgrids. It also offers advocacy suggestions for municipal leaders and officials to pursue at the state and regional level. The contents are targeted to municipal government staff but anyone looking for introductory material on microgrids should find it useful

Removal of Carbamazepine from Drinking Water

Due to the increasing prevalence of prescription medication over the past few decades, pharmaceuticals have accumulated in various water sources. This has become a public health concern because many pharmaceuticals have limited research on the effects of chronic low-level exposure. According to the World’s Health Organization (WHO), traces of pharmaceuticals products have been reported in different water sources such as surface waters, wastewater, groundwater, and drinking water.[1] One pharmaceutical of interest that has been detected in water sources is carbamazepine. Carbamazepine (CBZ) is a common pharmaceutical prescribed for the treatment of seizure disorders, neuropathic pain, and various psychological disorders. It’s mechanism of action is “sodium channel blocking,” which is the impairment of conduction of sodium ions in sodium channels. This, in effect, reduces nervous-system conductivity in key areas related to the treated disorders mentioned above.[2] Carbamazepine is also not easily biodegradable and current conventional treatment methods in some drinking water and wastewater facilities do not adequately remove carbamazepine and other pharmaceuticals from treated water. While carbamazepine is not federally regulated by the Environmental Protection Agency (EPA) under the Safe Water Drinking Act (SWDA) at this time, it does have the potential for producing adverse health effects in humans. Therefore, being proactive in finding ways to remove carbamazepine and compounds like it should be encouraged. The Carbamaza-Clean team designed a bench scale unit as well as an in-home treatment system using granular activated carbon (GAC) to effectively remove carbamazepine from water. GAC was chosen for this design because it is inexpensive and does not create by-products that are harmful to human health. Several experiments were conducted to determine the efficiency of the removal of carbamazepine using two different GACs: coconut shell GAC (CSGAC) and bituminous coal GAC (BGAC). A packed bed column was constructed to determine if both carbons could reduce the concentration of carbamazepine from 1 ppm to 1 ppb or lower. The CSGAC packed bed was able to lower the concentration below 1 ppb at a packed bed length of 4.4 ft, while the BGAC only required half that (2.2 ft). Both carbons can remove carbamazepine to the desired concentration; however, the costs vary. An economic analysis was performed to determine the costs of the carbons. The CSGAC system would cost $990 for the first year and$589.68 for each following year. The BGAC system would cost $639 for the first two years, and then$200 every two years following the initial capital investment

Hunting for landslides in St Lucia

Dr Colm Jordan and Dr Tom Dijkstra have both just returned from a trip to the Caribbean. This may sound like a glamorous location, but their work is associated with more serious matters

The effect of heterogeneity on decorrelation mechanisms in spiking neural networks: a neuromorphic-hardware study

High-level brain function such as memory, classification or reasoning can be realized by means of recurrent networks of simplified model neurons. Analog neuromorphic hardware constitutes a fast and energy efficient substrate for the implementation of such neural computing architectures in technical applications and neuroscientific research. The functional performance of neural networks is often critically dependent on the level of correlations in the neural activity. In finite networks, correlations are typically inevitable due to shared presynaptic input. Recent theoretical studies have shown that inhibitory feedback, abundant in biological neural networks, can actively suppress these shared-input correlations and thereby enable neurons to fire nearly independently. For networks of spiking neurons, the decorrelating effect of inhibitory feedback has so far been explicitly demonstrated only for homogeneous networks of neurons with linear sub-threshold dynamics. Theory, however, suggests that the effect is a general phenomenon, present in any system with sufficient inhibitory feedback, irrespective of the details of the network structure or the neuronal and synaptic properties. Here, we investigate the effect of network heterogeneity on correlations in sparse, random networks of inhibitory neurons with non-linear, conductance-based synapses. Emulations of these networks on the analog neuromorphic hardware system Spikey allow us to test the efficiency of decorrelation by inhibitory feedback in the presence of hardware-specific heterogeneities. The configurability of the hardware substrate enables us to modulate the extent of heterogeneity in a systematic manner. We selectively study the effects of shared input and recurrent connections on correlations in membrane potentials and spike trains. Our results confirm ...Comment: 20 pages, 10 figures, supplement

Deterministic networks for probabilistic computing

Neural-network models of high-level brain functions such as memory recall and reasoning often rely on the presence of stochasticity. The majority of these models assumes that each neuron in the functional network is equipped with its own private source of randomness, often in the form of uncorrelated external noise. However, both in vivo and in silico, the number of noise sources is limited due to space and bandwidth constraints. Hence, neurons in large networks usually need to share noise sources. Here, we show that the resulting shared-noise correlations can significantly impair the performance of stochastic network models. We demonstrate that this problem can be overcome by using deterministic recurrent neural networks as sources of uncorrelated noise, exploiting the decorrelating effect of inhibitory feedback. Consequently, even a single recurrent network of a few hundred neurons can serve as a natural noise source for large ensembles of functional networks, each comprising thousands of units. We successfully apply the proposed framework to a diverse set of binary-unit networks with different dimensionalities and entropies, as well as to a network reproducing handwritten digits with distinct predefined frequencies. Finally, we show that the same design transfers to functional networks of spiking neurons.Comment: 22 pages, 11 figure

Risk information services for Disaster Risk Management (DRM) in the Caribbean : mainstreaming opportunities

This document describes the assessment of opportunities for mainstreaming the satellite Earth Observation (EO) information products / services delivered by the British Geological Survey (BGS) via the framework of the European Space Agency (ESA) eoworld2 initiative. The products /services were delivered to the Caribbean region and the World Bank (WB) primarily via the ‘Caribbean Handbook on Risk Information Management’ project (CHARIM) which is financed by the EU-funded ACP-EU Natural Disaster Risk Reduction Program, managed by the Global Facility for Disaster Reduction and Recovery, led by the WB team, and implemented with the University of Twente, ITC and the local users from various Government Ministries in the Caribbean region. The prospect of increased exploitation and additional opportunities in further WB operations, programmes and initiatives is briefly addressed, as is an evaluation of further actions to be taken to further grow uptake of EO products / services across the WB in future

Residential back taxes and revitalization: a study of Winnipeg's Spence neighbourhood

report: ii, 28 pp.; ill., digital fileThe City of Winnipeg considers the Spence neighbourhood a Major Rehabilitation Area. Socio-economic conditions have deteriorated and the number of boarded-up and abandoned homes has increased. Community groups are calling for revitalization as the conditions escalate toward irreversible decay. Unfortunately, there are numerous barriers to urban revitalization; one obstacle for the redevelopment of homes in this area is the City of Winnipeg’s stringent tax policy. Many of the abandoned units have back taxes owing and are left vacant for up to five years before the city claims title to the property. If a private homeowner is in tax arrears and wants to give or sell the home for a nominal amount to a non-profit group, the city stresses that back taxes still have to be paid. Once the five-year tax sale process is completed, homes are easy to acquire from the city. The purpose of this investigation is to illustrate how detrimental a five-year waiting period can be for the already neglected housing stock and the perception of the neighbourhood, as well as its role in accelerating urban decay.Institute of Urban Studie