Life-cycle uses of water in U.S. electricity generation

Water use by the electric power industry is attracting renewed interest as periods and zones of arid weather are increasingly encountered, and various regional energy-production scenarios are evaluated. However, there is a scarcity of data on upstream water factors and discrepancies of data from different sources. We reviewed previous studies of water use in electricity generation and used full-life cycle accounting to evaluate water demand factors, both withdrawal and consumption, for conventional- and renewable-electrical power plants. Our investigation showed that moving to technologies like photovoltaics and wind offers the best option for conserving our water supply. We also emphasize the importance of employing a transparent, balanced approach in accounting life-cycle water usages.     

Multifunctional Nanocarriers for diagnostics, drug delivery and targeted treatment across blood-brain barrier: perspectives on tracking and neuroimaging

Nanotechnology has brought a variety of new possibilities into biological discovery and clinical practice. In particular, nano-scaled carriers have revolutionalized drug delivery, allowing for therapeutic agents to be selectively targeted on an organ, tissue and cell specific level, also minimizing exposure of healthy tissue to drugs. In this review we discuss and analyze three issues, which are considered to be at the core of nano-scaled drug delivery systems, namely functionalization of nanocarriers, delivery to target organs and in vivo imaging. The latest developments on highly specific conjugation strategies that are used to attach biomolecules to the surface of nanoparticles (NP) are first reviewed. Besides drug carrying capabilities, the functionalization of nanocarriers also facilitate their transport to primary target organs. We highlight the leading advantage of nanocarriers, i.e. their ability to cross the blood-brain barrier (BBB), a tightly packed layer of endothelial cells surrounding the brain that prevents high-molecular weight molecules from entering the brain. The BBB has several transport molecules such as growth factors, insulin and transferrin that can potentially increase the efficiency and kinetics of brain-targeting nanocarriers. Potential treatments for common neurological disorders, such as stroke, tumours and Alzheimer's, are therefore a much sought-after application of nanomedicine. Likewise any other drug delivery system, a number of parameters need to be registered once functionalized NPs are administered, for instance their efficiency in organ-selective targeting, bioaccumulation and excretion. Finally, direct in vivo imaging of nanomaterials is an exciting recent field that can provide real-time tracking of those nanocarriers. We review a range of systems suitable for in vivo imaging and monitoring of drug delivery, with an emphasis on most recently introduced molecular imaging modalities based on optical and hybrid contrast, such as fluorescent protein tomography and multispectral optoacoustic tomography. Overall, great potential is foreseen for nanocarriers in medical diagnostics, therapeutics and molecular targeting. A proposed roadmap for ongoing and future research directions is therefore discussed in detail with emphasis on the development of novel approaches for functionalization, targeting and imaging of nano-based drug delivery systems, a cutting-edge technology poised to change the ways medicine is administered.     

Robust cross layer optimization in relay aided cellular networks

A robust optimization framework for cross layer optimization is proposed to deal with time varying channels, reducing the required channel state feedback overhead and giving strong QoS guarantees. Lower bounds for the achieved goodput when robust scheduling is used are derived and through simulation we study the impact in terms of blocked calls and QoS achieved by the robust solution for two different cell topology layouts: when 2-hop relaying is allowed and when only direct base station to user transmissions are allowed. The results reveal that the price of robustness is lower for the 2-hop case than the single hop case.     

Multi-objective optimization with fuzzy measures and its application to flow-shop scheduling

Most of the research in multi-objective scheduling optimization uses the classical weighted arithmetic mean operator to aggregate the various optimization criteria. However, there are scheduling problems where criteria are considered interact and thus a different operator should be adopted. This paper is devoted to the search of Pareto-optimal solutions in a tri-criterion flow-shop scheduling problem (FSSP) considering the interactions among the objectives. A new hybrid meta-heuristic is proposed to solve the problem which combines a genetic algorithm (GA) for solutions evolution and a reduced variable neighborhood search (RVNS) technique for fast solution improvement. To deal with the interactions among the three criteria the discrete Choquet integral method is adopted as a means to aggregate the criteria in the fitness function of each individual solution. Experimental comparisons (over public available FSSP test instances) with five existing multi-objective evolutionary algorithms (including the well known SPEA2 and NSGAII algorithms as well as the recently published L-NSGA algorithm) showed a superior performance for the developed approach in terms of diversity and domination of solutions.     

PLATON: Peer-to-Peer load adjusting tree overlay networks

Peer-to-Peer systems supporting multi attribute and range queries use a number of techniques to partition the multi dimensional data space among participating peers. Load-balancing of data accross peer partitions is necessary in order to avoid the presence of network hotspots which may cause performance degradation or failures within the distributed environment. In this paper, we introduce a novel framework, PLATON, that preserves load balancing accross peer partitions when the multi-dimensional data space is dynamic, without requiring up-to-date global load information, e.g. information about the most loaded or least loaded peers in the network. A theoretical analysis on the upper bounds (ie. worst case) of the proposed algorithm is presented; its performance is evaluated in large-scale simulated networks and validated within in the PlanetLab emulation platform.     

Modeling beach realignment using a neuro-fuzzy network optimized by a novel backtracking search algorithm

Neural Computing and Applications - Beach realignment is caused by sediment movement across and along the beach due to the ever-changing incident waves. Its driving mechanisms are highly nonlinear...     

Internet Gaming Disorder: the interplay between physical activity and user–avatar relationship

Understanding both the risk and protective factors associated with Internet Gaming Disorder (IGD) has been viewed by many in the gaming studies field as an area of research priority. The present study focused on the potential risk and protective effects of user–avatar (game figure) relationship and physical activity (PA), respectively. To address these aims, a cross-sectional and a longitudinal mixed-methods design were combined (comprising both psychological and physiological assessments). A sample of 121 emerging adult gamers (18–29 years) residing in Australia, who played massively multiplayer online games, were assessed in relation to their IGD behaviours using the nine-item Internet Gaming Disorder Scale – Short Form. Additionally, the Proto-Self-Presence (PSP) scale was used to evaluate the extent to which gamers identified with the body of their avatar. Finally, a PA monitor (Fitbit Flex) measured levels of energy consumed during real-world daily activities (active minutes). A number of linear regressions and moderation analyses were conducted. Findings confirmed that PSP functioned as an IGD risk factor and that PA acted protectively, weakening the association between PSP and IGD behaviours. Implications of these findings are discussed in relation to IGD treatment and gaming development aspects.     

Angular dependence in infrared linear dichroism: a reevaluation of the theory

Parameters such as the viewing angle and the extinction ratio (the ratio of the transmitted light over the total light intensity that reaches the sample) are very important in the design of novel optical devices such as new types of polarizers, liquid crystal displays, etc. The initial aim of this work was the comparison of experimentally obtained results to the currently accepted theoretical model that is based on Zbinden's theory of intensity ellipsoid. Due to observed discrepancies between the above theory and experimental data, a new mathematical model was generated in order to adequately explain the experimental results. This new theory allows the calculation of light absorbance at every combination of azimuthal and tilt angles in complete agreement with the experimentally determined values. In addition, in this paper we settle, once and for all, the confusion that exists in the spectroscopic literature with regard to the dependence of absorption and transmission values vis-à-vis the angle of incidence of the incoming light. We conclusively show that it is absorptance (alpha) and not absorption or absorbance (A) which shows a cos(2) dependence on the angle formed by the electric vector and the dipole.     

Life-cycle nitrogen trifluoride emissions from photovoltaics

Amorphous- and nanocrystalline-silicon thin-film photovoltaic modules are made in high-throughput manufacturing lines that necessitate quickly cleaning the reactor. Using NF?, a potent greenhouse gas, as the cleaning agent triggered concerns as recent reports reveal that the atmospheric concentrations of this gas have increased significantly. We quantified the life-cycle emissions of NF? in photovoltaic (PV) manufacturing, on the basis of actual measurements at the facilities of a major producer of NF? and of a manufacturer of PV end-use equipment. From these, we defined the best practices and technologies that are the most likely to keep worldwide atmospheric concentrations of NF? at very low radiative forcing levels. For the average U.S. insolation and electricity-grid conditions, the greenhouse gas (GHG) emissions from manufacturing and using NF? in current PV a-Si and tandem a-Si/nc-Si facilities add 2 and 7 g CO?(eq)/kWh, which can be displaced within the first 1-4 months of the PV system life.