Full cost accounting for the life cycle of coal.

Each stage in the life cycle of coal-extraction, transport, processing, and combustion-generates a waste stream and carries multiple hazards for health and the environment. These costs are external to the coal industry and are thus often considered "externalities." We estimate that the life cycle effects of coal and the waste stream generated are costing the U.S. public a third to over one-half of a trillion dollars annually. Many of these so-called externalities are, moreover, cumulative. Accounting for the damages conservatively doubles to triples the price of electricity from coal per kWh generated, making wind, solar, and other forms of nonfossil fuel power generation, along with investments in efficiency and electricity conservation methods, economically competitive. We focus on Appalachia, though coal is mined in other regions of the United States and is burned throughout the world.

Low-cost high-efficiency GaN LED on large-area si substrate

The use of large size Si substrates for epitaxy of nitride light emitting diode (LED) structures has attracted great interest because Si wafers are readily available in large diameter at low cost. In addition, such wafers are compatible with existing processing lines for the 6-inch and larger wafer sizes commonly used in the electronics industry. With the development of various methods to avoid wafer cracking and reduce the defect density, the performance of GaN-based LED and electronic devices has been greatly improved. In this paper, we review our methods of growing crack-free InGaN-GaN multiple quantum well (MQW) LED structures of high crystalline quality on Si(111) substrates. The performance of processed LED devices and its dependence on the threading dislocation density were studied. Full wafer-level LED processing using a conventional 6-inch III-V processing line is also presented, demonstrating the great advantage of using large-size Si substrates for mass production of GaN LED devices.

Stabilising terminal cost and terminal controller for ℓasso- MPC: Enhanced optimality and region of attraction

In recent literature, ℓ1-regularised MPC, or ℓasso-MPC, has been recommended for control tasks involving complex requirements on the control signals, for instance, the simultaneous solution of regulation and sharp control allocation for redundantly-actuated systems. This is due to the implicit thresholding ability of LASSO regression. In this paper, a stabilising terminal cost featuring a mixed ℓ1/ℓ2 2 penalty is presented. Then, a candidate terminal controller is computed, with the aim of enlarging the region of attraction. © 2013 EUCA.

Low-cost PCB-integrated polymer waveguide sensor for gas detection

An optical waveguide sensor formed directly on low-cost PCB substrates is presented for the first time. The device integrates polymer waveguides functionalized with chemical dyes, photonic and electronic components and allows multiple-gas detection. © OSA/CLEO 2011.

40 Gb/s carrierless amplitude and phase modulation for low-cost optical datacommunication links

4 bps/Hz 40 Gb/s carrierless amplitude and phase (CAP) modulation is investigated for nextgeneration datacommunication links. The 40 Gb/s link achieves double the length of a conventional NRZ scheme, despite using a low-bandwidth source. © OSA/OFC/NFOEC 2011.

Fast low-cost FIR filter processed ECDM labels for optical label switching

A code-label recognition time of less than 500ps is demonstrated using low-cost FIRfilters. The electronically-processed label provides a control signal from an auto-correlated label. Error-free electronic code-label switching of an optical 10Gb/s signal is demonstrated. © 2010 Optical Society of America.

Carrierless amplitude and phase modulation for low-cost,high-spectral-efficiency optical datacommunication links

Carrierless amplitude and phase modulation for next-generation datacommunication links is considered for the first time. Low-cost implementation of a high-spectral-efficiency 10 Gb/s channel is demonstrated as a route to links at 40 Gb/s and beyond. © 2010 Optical Society of America.

Low cost optical access networks using 20 Gchip/s electronic CMDA

This paper describes electronically processed CDMA techniques which allow Gb/s data rates for each user in passive optical networks. We will present recent progress including a 16 chip Walsh-code system operating at 18 Gchip/s supporting up to 16 users. © 2009 IEEE.

Cost-effectiveness of alternative powertrains for reduced energy use and CO2 emissions in passenger vehicles

This work analysed the cost-effectiveness of avoiding carbon dioxide (CO2) emissions using advanced internal combustion engines, hybrids, plug-in hybrids, fuel cell vehicles and electric vehicles across the nine UK passenger vehicles segments. Across all vehicle types and powertrain groups, minimum installed motive power was dependent most on the time to accelerate from zero to 96.6km/h (60mph). Hybridising the powertrain reduced the difference in energy use between vehicles with slow (t z - 60 > 8 s) and fast acceleration (t z - 60 < 8 s) times. The cost premium associated with advanced powertrains was dependent most on the powertrain chosen, rather than the performance required. Improving non-powertrain components reduced vehicle road load and allowed total motive capacity to decrease by 17%, energy use by 11%, manufacturing cost premiums by 13% and CO2 emissions abatement costs by 15%. All vehicles with advanced internal combustion engines, most hybrid and plug-in hybrid powertrains reduced net CO2 emissions and had lower lifetime operating costs than the respective segment reference vehicle. Most powertrains using fuel cells and all electric vehicles had positive CO2 emissions abatement costs. However, only vehicles using advanced internal combustion engines and parallel hybrid vehicles may be attractive to consumers by the fuel savings offsetting increases in vehicle cost within two years. This work demonstrates that fuel savings are possible relative to today's fleet, but indicates that the most cost-effective way of reducing fuel consumption and CO2 emissions is by advanced combustion technologies and hybridisation with a parallel topology. © 2014 Elsevier Ltd.

100 Gb/s uncooled DWDM using orthogonal coding for low-cost datacommunication links

We demonstrate a 10 x 10 Gb/s uncooled DWDM system using orthogonal coding on adjacent carriers, assuming the use of a monolithically integrated sources. A power saving of 72% is expected over traditional WDM. © 2014 OSA.

Silicon avalanche photodiodes for low cost, high loss short wavelength radio over fiber links

An APD is shown to improve the noise figure of a lossy optical link compared to a PIN-TIA combination of equivalent gain. Transmission of IEEE 802.11g WLAN signals is demonstrated with 18dB optical link loss. © 2009 Optical Society of America.