Life cycle assessment of membrane-based carbon capture and storage

Many investigations have conducted life cycle assessments (LCA) of the most commonly discussed routes of carbon capture and storage (CCS): post-combustion with amine wash separation; oxyfuel using cryogenic air separation and pre-combustion by integrated gasification combined cycle (IGCC) using physical separation. A research alliance developed corresponding separation systems using different types of membranes to allow a more energy efficient separation process: polyactive polymeric membranes for post-combustion, ceramic membranes for oxyfuel and metallic membranes for IGCC separation. By conducting an LCA, the study examines the actual greenhouse gas emissions and other environmental impacts of the new membrane separation technologies, together with concepts implementing the more common technologies. The reference systems represent today’s state-of-the-art supercritical coal fired power plant in Germany, together with a more advanced ultra-supercritical plant operating at 700 °C without CO₂ capture. The results demonstrate that among the three reference power plants the IGCC is the superior concept due to the highest efficiency. Regarding climate change, the IGCC power plants with CO₂ capture are still the best concepts. When other environmental impacts are considered, the capture technologies are inferior. The membrane concepts show the overall better results in comparison to the conventional capture technologies. The environmental impacts for membrane applications add a new range of findings to the field of CCS LCAs. Now the results for several different approaches can be compared directly for the first time.     

Technologies for trapped-ion quantum information systems

Scaling up from prototype systems to dense arrays of ions on chip, or vast networks of ions connected by photonic channels, will require developing entirely new technologies that combine miniaturized ion trapping systems with devices to capture, transmit, and detect light, while refining how ions are confined and controlled. Building a cohesive ion system from such diverse parts involves many challenges, including navigating materials incompatibilities and undesired coupling between elements. Here, we review our recent efforts to create scalable ion systems incorporating unconventional materials such as graphene and indium tin oxide, integrating devices like optical fibers and mirrors, and exploring alternative ion loading and trapping techniques.

     

Electrophysiologic mechanisms of antiarrhythmic efficacy of a sotalol and class Ia drug combination: elimination of reverse use dependence

We have generated a C-terminally-truncated form of recombinant tissue inhibitor of metalloproteinases-2 (designated rTIMP-2 delta) in which the region of the inhibitor extending from residue 128 to 194 and including 3 of the 6 disulfide bonds is deleted. rTIMP-2 and rTIMP-2 delta had similar inhibitory activities toward interstitial collagenase and inhibited the activation of the precursor form of matrix metalloproteinase-2 (proMMP-2). rTIMP-2 also bound with high affinity (Kd 0.99 nM) to HT1080 human fibrosarcoma cells treated with 12-O-tetradecanoyl-phorbol-13-acetate. However deletion of the C-terminal domain of TIMP-2 significantly lowered the cell surface binding affinity, with competition experiments indicating a 2 order of magnitude difference between rTIMP-2 and rTIMP-2 delta in the concentrations needed to displace 125I-labeled rTIMP-2 binding. These data indicate that the C-terminal domain of TIMP-2 is not required for the antimetalloproteinase activity but plays a major role in the high affinity cell surface binding of the inhibitor.     

Potential of CDMA450 for rural network connectivity

This article evaluates CDMA450 as a potential solution for rural data and voice connectivity. We begin by analyzing the main strengths of CDMA450, but also some of the potential limitations for rural coverage, from both a technical and an economic standpoint. We argue that CDMA450 is a promising technology, competitive in both capacity-centric urban environments and in coverage-centric rural environments. Consequently, we discuss the opportunities of providing universal coverage by adopting a business model targeting both urban and rural deployments, and utilizing urban to rural cross-subsidization. We then explore the advantages of deploying CDMA450 using a fixed wireless (WLL) model. To this end, we explore the effective range of WLL CDMA450, and the impact of using directional antennas and receive antenna diversity in real-world commercial CDMA450 deployment in Romania. If used properly, these techniques can aid us in increasing cell radii and thus lead to substantial cost benefits     

Improved Method for Creating Time-Domain Unsteady Aerodynamic Models

Multidisciplinary aeroservoelastic interactions are studied by the combination of knowledge acquired in two main disciplines: aeroelasticity and servocontrols. In aeroelasticity, the doublet lattice method is used to calculate the unsteady aerodynamic forces for a range of reduced frequencies and Mach numbers on a business aircraft in the subsonic flight regime by use of NASTRAN software. For aeroservoelasticity studies, there is the need to conceive methods for these unsteady aerodynamic forces conversions from frequency into Laplace domain. A new method different from classical methods is presented, in which Chebyshev polynomials theories and their orthogonality properties are applied. In this paper, a comparison between flutter results expressed in terms of flutter speeds and frequencies obtained with our method with flutter results obtained with classical Padé and least squares methods is presented for a business aircraft at one Mach number and a range of reduced frequencies. It has been found that results obtained with our method are better in terms of average error than results obtained with the two classical methods here presented.     

Childhood ADHD symptoms and risk for cigarette smoking during adolescence: School adjustment as a potential mediator.

Although a large body of research suggests that children with attention-deficit/hyperactivity disorder (ADHD) are at increased risk for cigarette smoking during adolescence compared with their non-ADHD peers, much less research has examined why. The current study addressed this gap in the literature by examining middle school adjustment, broadly defined, as a possible mediator of the relation between childhood ADHD symptoms and cigarette smoking during middle adolescence (10th grade). Longitudinal data were collected from a community sample of 754 youth using self-report and parent report along with school records, and a novel statistical technique was used in the process of testing for mediation. Consistent with hypotheses, school adjustment was found to mediate the relation between childhood ADHD symptoms and later cigarette smoking, even after controlling for early externalizing problems. Results have implications for etiological theories of adolescent deviant behavior and suggest that successful smoking prevention programs targeting youth with ADHD should include a school adjustment component. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Anodic aqueous electrophoretic deposition of titanium dioxide using carboxylic acids as dispersing agents

The dispersion of anatase phase TiO₂ powder in aqueous suspensions was investigated by zeta-potential and agglomerate size analysis. The iso-electric point (IEP) of anatase was determined to be at pH 2.8 using monoprotic acids for pH adjustment. In comparison, it was found that the use of carboxylic acids, citric and oxalic, caused a decrease in zeta-potential through the adsorption of negatively charged groups to the particle surfaces. The use of these reagents was shown to enable effective anodic electrophoretic deposition (EPD) of TiO₂ onto graphite substrates at low pH levels with a decreased level of bubble damage in comparison with anodic EPD from basic suspensions. The results obtained demonstrate that the IEP of TiO₂ varies with the type of reagent used for pH adjustment. The low pH level of the IEP and the ability to decrease the zeta-potential through the use of carboxylic acids suggest that the anodic EPD of anatase is more readily facilitated than cathodic EPD.     

Seismic design of outrigger systems using equivalent energy design procedure

An outrigger system is an effective structural scheme that is commonly used in high‐rise construction to increase the stiffness of concrete core walls and to reduce the moment demand within the walls. Despite the on‐going use of outrigger systems around the world, a formal seismic design procedure is yet available. This paper presents an equivalent energy design procedure (EEDP) to design outrigger systems for seismic applications. Three prototype outrigger‐wall buildings of various heights are designed for Vancouver, Canada. Detailed finite element models are developed to assess the seismic performance of the prototype buildings and to assess the safety using the FEMA P695 methodology. The result shows that EEDP is an efficient method to design outrigger systems which results in structures that can achieve sufficient margin of safety against collapse and satisfy multiple performance objectives at different seismic hazard levels.