The Economic Costs and Benefits of Implementing the Clean Power Plan

This brief looks at the costs of implementing the EPA’s Clean Power Plan. Specifically, it examines whether implementing the CPP on a state-by-state basis—that is, with each state meeting its own individual target for emissions reduction by 2030, rather than establishing regional targets—is economically efficient. The economic analysis uses data from electricity-generating firms participating in the Pennsylvania-New Jersey-Maryland (PJM) Interconnection to examine the relative economic efficiency of regional versus state-by-state implementation of the CPP. The research indicates that state-by-state implementation would yield the lowest electricity prices in 2030.https://repository.upenn.edu/pennwhartonppi/1041/thumbnail.jp

Characterisation by EIS of ternary Mg alloys synthesised by mechanical alloying

Electrochemical impedance spectroscopy has been used to study the electrochemical behaviour of ternary Mg60Ti10Si30 and Mg88Ti5Si7 alloy samples fabricated by mechanical alloying of the elemental powders in an argon atmosphere. The influence of different milling times up to 25 h and heat treatment on the electrochemical behaviour of the samples, after compacting under pressure into disks, has been investigated in 0.1 M Na2SO4 and 0.01 M NaCl electrolyte solutions. Complementary measurements of open circuit potential, polarisation curves, and surface and microstructural analysis have been carried out. The experimental results revealed that corrosion is greater for Mg88Ti5Si7 which contains free magnesium; however, in sulphate solution a protective oxide layer formed can reduce the corrosion rate. In Mg60Ti10Si30, heat treatment increases corrosion, which is explained through a greater tendency for pitting corrosion. Comparison is made between the electrochemical impedance data and the nanophase structure as well as with the electrochemical behaviour of other magnesium alloys.http://www.sciencedirect.com/science/article/B6TG0-4H21KGF-3/1/564bda28bb49702cb8769e10e8e350a

Automatic Error Detection in Integrated Circuits Image Segmentation: A Data-driven Approach

Due to the complicated nanoscale structures of current integrated circuits(IC) builds and low error tolerance of IC image segmentation tasks, most existing automated IC image segmentation approaches require human experts for visual inspection to ensure correctness, which is one of the major bottlenecks in large-scale industrial applications. In this paper, we present the first data-driven automatic error detection approach targeting two types of IC segmentation errors: wire errors and via errors. On an IC image dataset collected from real industry, we demonstrate that, by adapting existing CNN-based approaches of image classification and image translation with additional pre-processing and post-processing techniques, we are able to achieve recall/precision of 0.92/0.93 in wire error detection and 0.96/0.90 in via error detection, respectively

Transfer printing of AlGaInAs/InP etched facet lasers to Si substrates

InP-etched facet ridge lasers emitting in the optical C-band are heterogeneously integrated on Si substrates by microtransfer printing for the first time. 500 μm × 60 μm laser coupons are fabricated with a highly dense pitch on the native InP substrate. The laser epitaxial structure contains a 1-μm-thick InGaAs sacrificial layer. A resist anchoring system is used to restrain the devices while they are released by selectively etching the InGaAs layer with FeCl3:H2O (1:2) at 8 °C. Efficient thermal sinking is achieved by evaporating Ti-Au on the Si target substrate and annealing the printed devices at 300 °C. This integration strategy is particularly relevant for lasers being butt coupled to polymer or silicon-on-insulator (SOI) waveguides

Late Descemet Membrane Detachment After Uneventful Cataract Surgery

Purpose: To report 5 patients with late Descemet membrane (DM) detachment after uneventful cataract surgery. Observations: After a retrospective chart analysis of consecutive patients that developed DM detachment after uneventful cataract surgery, six eyes of five patients were enrolled. In all cases, patients reported good vision initially after cataract surgery. Within days to months, these patients developed late DM detachment with decreased vision. In one patient, the detachment affected both eyes. Filtered air or diluted sulfur hexafluoride were injected in the anterior chamber to tamponade the DM detachment. In five eyes, the cornea cleared after DM reattachment. In two eyes of the same patient, DM reattached spontaneously requiring no further surgical intervention. In one patient, the Descemet failed to reattach and required an endothelial keratoplasty. Conclusion and importance: Descemet membrane detachment may occur after uneventful cataract surgery. Filtered air or long-lasting intraocular gas may be used to reattach DM. Spontaneous DM reattachment may also occur and surgeons should be aware of this to avoid unnecessary procedures

Evolution of a key enzyme of aerobic metabolism reveals Proterozoic functional subunit duplication events and an ancient origin of animals

The biological toolkits for aerobic respiration were critical for the rise and diversification of early animals. Aerobic life forms generate ATP through the oxidation of organic molecules in a process known as Krebs’ Cycle, where the enzyme isocitrate dehydrogenase (IDH) regulates the cycle's turnover rate. Evolutionary reconstructions and molecular dating of proteins related to oxidative metabolism, such as IDH, can therefore provide an estimate of when the diversification of major taxa occurred, and their coevolution with the oxidative state of oceans and atmosphere. To establish the evolutionary history and divergence time of NAD-dependent IDH, we examined transcriptomic data from 195 eukaryotes (mostly animals). We demonstrate that two duplication events occurred in the evolutionary history of NAD-IDH, one in the ancestor of eukaryotes approximately at 1967 Ma, and another at 1629 Ma, both in the Paleoproterozoic Era. Moreover, NAD-IDH regulatory subunits β and γ are exclusive to metazoans, arising in the Mesoproterozoic. Our results therefore support the concept of an ‘‘earlier-than-Tonian’’ diversification of eukaryotes and the pre-Cryogenian emergence of a metazoan IDH enzyme

Site-specific management of miscanthus genotypes for combustion and anaerobic digestion:A comparison of energy yields

In Europe, the perennial C4 grass miscanthus is currently mainly cultivated for energy generation via combustion. In recent years, anaerobic digestion has been identified as a promising alternative utilization pathway. Anaerobic digestion produces a higher-value intermediate (biogas), which can be upgraded to biomethane, stored in the existing natural gas infrastructure and further utilized as a transport fuel or in combined heat and power plants. However, the upgrading of the solid biomass into gaseous fuel leads to conversion-related energy losses, the level of which depends on the cultivation parameters genotype, location, and harvest date. Thus, site-specific crop management needs to be adapted to the intended utilization pathway. The objectives of this paper are to quantify (i) the impact of genotype, location and harvest date on energy yields of anaerobic digestion and combustion and (ii) the conversion losses of upgrading solid biomass into biogas. For this purpose, five miscanthus genotypes (OPM 3, 6, 9, 11, 14), three cultivation locations (Adana, Moscow, Stuttgart), and up to six harvest dates (August-March) were assessed. Anaerobic digestion yielded, on average, 35% less energy than combustion. Genotype, location, and harvest date all had significant impacts on the energy yield. For both, this is determined by dry matter yield and ash content and additionally by substrate-specific methane yield for anaerobic digestion and moisture content for combustion. Averaged over all locations and genotypes, an early harvest in August led to 25%and a late harvest to 45%conversion losses. However, each utilization option has its own optimal harvest date, determined by biomass yield, biomass quality, and cutting tolerance. By applying an autumn green harvest for anaerobic digestion and a delayed harvest for combustion, the conversion-related energy loss was reduced to an average of 18%. This clearly shows that the delayed harvest required tomaintain biomass quality for combustion is accompanied by high energy losses through yield reduction over winter. The pre-winter harvest applied in the biogas utilization pathway avoids these yield losses and largely compensates for the conversion-related energy losses of anaerobic digestion