Low carbon housing: lessons from Elm Tree Mews

This report sets out the findings from a low carbon housing trial at Elm Tree Mews, York, and discusses the technical and policy issues that arise from it. The Government has set an ambitious target for all new housing to be zero carbon by 2016. With the application of good insulation, improved efficiencies and renewable energy, this is theoretically possible. However, there is growing concern that, in practice, even existing carbon standards are not being achieved and that this performance gap has the potential to undermine zero carbon housing policy. The report seeks to address these concerns through the detailed evaluation of a low carbon development at Elm Tree Mews. The report: * evaluates the energy/carbon performance of the dwellings prior to occupation and in use; * analyses the procurement, design and construction processes that give rise to the performance achieved; * explores the resident experience; * draws out lessons for the development of zero carbon housing and the implications for government policy; and * proposes a programme for change, designed to close the performance gap

Electrical and Structural Analysis of CNT-Metal Contacts in Via Interconnects

Vertically aligned carbon nanotubes grown by plasmaenhanced chemical vapor deposition offer a potentially suitable material for via interconnects in next-generation integrated circuits. Key performance-limiting factors include high contact resistance and low carbon nanotube packing density, which fall short of meeting the requirements delineated in the ITRS roadmap for interconnects. For individual carbon nanotube s, contact resistance is a major performance hurdle since it is the dominant component of carbon nanotube interconnect resistance, even in the case of vertically aligned carbon nanotube arrays. In this study, we correlate the carbon nanotube-metal interface nanostructure to their electrical properties in order to elucidate growth parameters that can lead to high density and low contact resistance and resistivity

Nanowrinkled Carbon Aerogels Embedded with FeN x Sites as Effective Oxygen Electrodes for Rechargeable Zinc-Air Battery.

Rational design of single-metal atom sites in carbon substrates by a flexible strategy is highly desired for the preparation of high-performance catalysts for metal-air batteries. In this study, biomass hydrogel reactors are utilized as structural templates to prepare carbon aerogels embedded with single iron atoms by controlled pyrolysis. The tortuous and interlaced hydrogel chains lead to the formation of abundant nanowrinkles in the porous carbon aerogels, and single iron atoms are dispersed and stabilized within the defective carbon skeletons. X-ray absorption spectroscopy measurements indicate that the iron centers are mostly involved in the coordination structure of FeN4, with a minor fraction (ca. 1/5) in the form of FeN3C. First-principles calculations show that the FeN x sites in the Stone-Wales configurations induced by the nanowrinkles of the hierarchically porous carbon aerogels show a much lower free energy than the normal counterparts. The resulting iron and nitrogen-codoped carbon aerogels exhibit excellent and reversible oxygen electrocatalytic activity, and can be used as bifunctional cathode catalysts in rechargeable Zn-air batteries, with a performance even better than that based on commercial Pt/C and RuO2 catalysts. Results from this study highlight the significance of structural distortions of the metal sites in carbon matrices in the design and engineering of highly active single-atom catalysts

A review of agricultural waste activated carbon and effect on adsorption parameters

Activated carbon is widely used in industrial wastewater treatment operation because of the effectiveness in removing the dye. As the conventional activated carbon on market nowadays is expensive, lots of research was done on agricultural materials to replace the activated carbon. Sugarcane bagasse is listed as one of the agricultural material alternatives. This review compiles the characterisation of sugarcane bagasse and several agricultural wastes-based activated carbon including proximate analysis, ultimate analysis, and activated carbon surface characteristic used to remove dye in textile wastewater. Nevertheless, the adsorption parameters are the main focus as it affecting the removal of dye. The expansion review regarding activated carbon performance implies that dye removal efficiency depends on the amount of adsorbent dosage, contact time, pH solution, dye concentration applied during the adsorption process. This review shows the need of thoughtful information on adsorption parameters with an expanded list of various types of agricultural-based activated carbon and various dye removal

Actual energy performance of a zero-carbon neighbourhood

The evolution towards zero-energy buildings and districts brings along uncertainties about the operational performance, strengths and weaknesses of these technologies, that are often new and unfamiliar to both the designers, owners and users. In Kortrijk, an exemplary zero-carbon neighbourhood is designed, built and evaluated in the framework of a European demonstration project ECO-Life ‘Sustainable zero-carbon ECO-town developments improving quality of life across EU’. The neighbourhood counts about 200 dwellings in highly energy-efficient buildings with different ventilation technologies and collective RES based on solar, biomass or aero-thermal energy. During the building process and the first years of operation, the energy performance of the neighbourhood is evaluated after intensive monitoring and testing by Ghent University’s research group of building physics, construction and services. This paper presents two focal points of the research: the energy demand of the buildings and the interaction with the occupants, and the energy performance of the neighbourhoods' low-temperature district heating system

Storage of hydrogen in nanostructured carbon materials

Recent developments focusing on novel hydrogen storage media have helped to benchmark nanostructured carbon materials as one of the ongoing strategic research areas in science and technology. In particular, certain microporous carbon powders, carbon nanomaterials, and specifically carbon nanotubes stand to deliver unparalleled performance as the next generation of base materials for storing hydrogen. Accordingly, the main goal of this report is to overview the challenges, distinguishing traits, and apparent contradictions of carbon-based hydrogen storage technologies and to emphasize recently developed nanostructured carbon materials that show potential to store hydrogen by physisorption and/or chemisorption mechanisms. Specifically touched upon are newer material preparation methods as well as experimental and theoretical attempts to elucidate, improve or predict hydrogen storage capacities, sorption–desorption kinetics, microscopic uptake mechanisms and temperature–pressure–loading interrelations in nanostructured carbons, particularly microporous powders and carbon nanotubes

Ablative performance of carbon-carbon nosetips in simulated re-entry environments

A summary is presented of ablation performance data for carbon-carbon nosetip models obtained over a range of pressures from 10 to 168 atm. Two classes of tests are reviewed: (1) steady state, in which a constant environment is imposed on the model, and (2) ramp, in which the pressure is increased from 10 to 80 atmospheres to simulate re-entry pressure history. Comparison of arc test parameters with typical reentry vehicle parameters is included, to assess the adequacy of the test simulation. Based on this comparison, recommendations are made for facility developments which would yield improved simulation capability for reentry vehicle nosetip ablative performance

Time-series cross-sectional environmental performance and disclosure relationship:specific evidence from a less-developed country

This paper relies on ‘vulnerability and exploitability’ framework to submit new insights into legitimacy theory and voluntary disclosure theory using specific empirical evidence from the Nigerian oil and gas industry. The study connects the voluntary and legitimizing disclosure behaviors, regarding carbon emission due to gas flaring, of dominant companies in the Nigerian upstream petroleum sector to the vulnerability and exploitability of Nigeria as a less developed country. The hypothesized relations between gas flaring-related environmental performance and two forms of its disclosure (volume and substance) are estimated and tested using Prais-Winsten regression with Panel Corrected Standard Errors (PCSE). While the paper uses Data Envelopment Analysis (DEA) to measure gas flaring-related carbon performance, the two forms of gas flaring-related disclosures are measured using content analysis. We document significant positive and negative association between gas flaring-related carbon emission performance, on one hand, and the volumetric disclosure and disclosure substance on the other hand. These results imply that while the positive relation confirms the vulnerable nature of Nigeria as a less developed country, the negative relation is linked to the country’s exploitability. It is also empirically established that environmental performance is one of the key factors responsible for the undulating trend in the volume of environmental disclosures by large corporations operating in less-developed countries