Evaluating Self-Generated Information: Anterior Prefrontal Contributions to Human Cognition.

The anterior or rostrolateral prefrontal cortex (RLPFC) is frequently recruited during complex cognitive tasks across a wide range of domains, including reasoning, long-term memory retrieval, and working memory. The authors report an event-related functional MRI study, indicating that the RLPFC is specifically involved in the evaluation of internally generated information--or information that cannot be readily perceived from the external environment but has to be inferred or self-generated. The findings are consistent with a hierarchical model of lateral prefrontal organization, with RLPFC contributing only at the highest orders of cognitive transformations. This characterization of RLPFC function may help explain seemingly disparate findings across multiple cognitive domains and could provide a unified account of this region's contribution to human cognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Counterfactual Thinking and the First Instinct Fallacy.

Most people believe that they should avoid changing their answer when taking multiple-choice tests. Virtually all research on this topic, however, has suggested that this strategy is ill-founded: Most answer changes are from incorrect to correct, and people who change their answers usually improve their test scores. Why do people believe in this strategy if the data so strongly refute it? The authors argue that the belief is in part a product of counterfactual thinking. Changing an answer when one should have stuck with one's original answer leads to more "if only . . ." self-recriminations than does sticking with one's first instinct when one should have switched. As a consequence, instances of the former are more memorable than instances of the latter. This differential availability provides individuals with compelling (albeit illusory) personal evidence for the wisdom of always following their 1st instinct, with suboptimal test scores the result. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Persistence of Preference for a Flavor Presented in Simultaneous Compound With Sucrose.

Rats exposed to a simultaneous compound of a flavor and sucrose subsequently exhibited a preference for the flavor over water. This preference persisted across repeated testing even though the flavor was presented in the absence of sucrose. The preference did, however, extinguish if the rats were hungry when trained or tested, or if they had been reexposed to sucrose between training and test. Though failing to extinguish the preference, presentation of the flavor outside the compound protected it from the effects of sucrose devaluation, indicating that these presentations extinguished the within-compound association between the flavor and sucrose. The authors conclude that the hedonic reaction elicited by sucrose imbues the flavor with the same hedonic properties, and these properties maintain the preference independently of the flavor-sucrose association. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adding compression to a full-text retrieval system

We describe the implementation of a data compression scheme as an integral and transparent layer within a full-text retrieval system. Using a semi-static word-based compression model, the space needed to store the text is under 30 per cent of the original requirement. The model is used in conjunction with canonical Huffman coding and together these two paradigms provide fast decompression. Experiments with 500 Mb of newspaper articles show that in full-text retrieval environments compression not only saves space, it can also yield faster query processing - a win-win situation.     

Flame-Based Technologies and Reactive Spray Deposition Technology for Low-Temperature Solid Oxide Fuel Cells: Technical and Economic Aspects

The economic and technical breakthroughs in solid oxide fuel cell (SOFC) for commercial success still depend on high-quality manufacture, reliability, efficiency, and must have an acceptable cost when compared to competing technologies. The application of flame-based technologies as a one-step deposition technique for SOFC component manufacture has potential to reduce both cost and production time. In this article, cells produced by flame processes have been reviewed with emphases placed on the Reactive Spray Deposition Technology technique. Various experimental methods and examples for the synthesis of porous electrodes and dense electrolytes are reviewed. The studies focus on determining the range of the flame conditions under which each of the individual cell components for low temperature SOFC applications ~600 °C could be successfully deposited.     

Reservoir Inflow Monitoring for Improved Management of Treated Water Quality—A South Australian Experience

Large tributary inflows into water supply reservoirs caused by heavy catchment rain may be of concern due to problems associated with high levels of natural organic matter (NOM) present in the inflows. The movement of these inflows within a reservoir is dependent on its relative density to the receiving waters. For example, if the inflow is denser (colder) than the recipient water it will travel along the base of the reservoir as an underflow and can penetrate as far as the dam wall water off-take to a water treatment plant (WTP). Field studies were conducted to track the passage of underflows through two South Australian reservoirs, Little Para and Myponga. Samples were collected before and during storm event inflows and analyses undertaken to determine NOM concentration, alum demand, disinfection by-product formation potential, and quality of the water. We demonstrate that by monitoring the movement of inflows into reservoirs, combined with changes in reservoir off-take levels, that the risk of NOM entering a water treatment plant can be reduced which in turn will lower water treatment costs by reducing alum dosing levels and lessen the risk to human health by reducing disinfection by-product formation.     

NLCC controller for SEPIC-based micro-wind energy conversion system

The growth of the power industry is gaining greater momentum as the usage of the non-conventional energy sources that include fuel, solar, and wind energies, increases. Wind energy conversion systems (WECSs) are gaining more popularity and are expected to be able to control the power at the output. This paper describes the current control (CC), non-linear carrier charge control (NLCCC), and fuzzy logic control (FLC) applied to the single-ended primary inductor converter (SEPIC)-based WECS. The current controller has an inherent overcurrent protection with better line noise rejection. The pulses for the switch of the SEPIC are obtained by comparing the current flowing through it with the virtual current reference. FLC is also investigated for the micro-wind energy conversion system (μWECS), since it improves the damping characteristics of WECS over a wide range of operating points. This cannot attain the unity power factor rectification. In this paper, NLCCC is proposed for high-power factor rectifier-based SEPIC in continuous conduction mode (CCM) for μWECS. The proposed converter provides an output voltage with low input current ripple due to the presence of the inductor at the input side. By comparing the signal proportional to the integral of switch current with a periodic non-linear carrier wave, the duty ratio of the converter switch is determined for the NLCC controller. By selecting the shape of the periodic non-linear carrier wave the input-line current can be made to follow the input-line voltage. This work employs a parabolic carrier waveform generator. The output voltage is regulated for changes in the wind speed. The results obtained prove the effectiveness of the NLCC controller in improving the power factor.     

Rate management in multiuser detection based MAC design for ad hoc networks

We propose a framework that produces synergy between Medium Access Control (MAC) and physical layers in order to increase the users’ individual throughput in a high-capacity CDMA ad hoc network. The MAC layer supports a multiuser detection based access protocol. Users send data packets at different rates, depending on the fading channel state. The framework is based on an LMS (Least Mean Square) prediction algorithm that estimates channel gain at the physical layer. The performance of the scheme is evaluated by simulations. Multiuser detection typically triples the throughput of ad hoc networks but our prediction-based scheme further doubles this metric. The main advantage of the proposed scheme is its flexibility and efficiency in a wide range of data rates and target bit error rates. It is also well fitted to support high-quality multi-media transmissions, and to improve the performance of applications that require high quality of service (QoS).     

CCN spectra, hygroscopicity, and droplet activation kinetics of secondary organic aerosol resulting from the 2010 Deepwater Horizon oil spill

Secondary organic aerosol (SOA) resulting from the oxidation of organic species emitted by the Deepwater Horizon oil spill were sampled during two survey flights conducted by a National Oceanic and Atmospheric Administration WP-3D aircraft in June 2010. A new technique for fast measurements of cloud condensation nuclei (CCN) supersaturation spectra called Scanning Flow CCN Analysis was deployed for the first time on an airborne platform. Retrieved CCN spectra show that most particles act as CCN above (0.3 ± 0.05)% supersaturation, which increased to (0.4 ± 0.1)% supersaturation for the most organic-rich aerosol sampled. The aerosol hygroscopicity parameter, κ, was inferred from both measurements of CCN activity and from humidified-particle light extinction, and varied from 0.05 to 0.10 within the emissions plumes. However, κ values were lower than expected from chemical composition measurements, indicating a degree of external mixing or size-dependent chemistry, which was reconciled assuming bimodal, size-dependent composition. The CCN droplet effective water uptake coefficient, γ(cond), was inferred from the data using a comprehensive instrument model, and no significant delay in droplet activation kinetics from the presence of organics was observed, despite a large fraction of hydrocarbon-like SOA present in the aerosol.     

Tunability and stability of gold nanoparticles obtained from chloroauric Acid and sodium thiosulfate reaction

ABSTRACT: In the quest for producing an effective clinically relevant therapeutic agent, scalability, repeatability, and stability are paramount. In this paper, gold nanoparticles (GNPs) with precisely controlled near infrared (NIR) absorption are synthesized by a single step reaction of HAuCl4 and Na2S2O3, without assistance of additional templates, capping reagents or seeds. The anisotropy in the shape of gold nanoparticles offers high NIR absorption making it therapeutically relevant. The synthesized products consist of GNPs with different shape and size, including small spherical colloid gold particles and non-spherical gold crystals. The NIR absorption wavelengths and particle size increase with increasing molar ratio of HAuCl4/Na2S2O3. Non-spherical gold particles can be further purified and separated by centrifugation to improve the NIR absorbing fraction of particles. In-depth studies reveal that GNPs with good structural and optical stability only form in a certain range of the HAuCl4/Na2S2O3 molar ratio, whereas higher molar ratios result in unstable GNPs, which lose their NIR absorption peak due to decomposition and reassembly via Ostwald ripening. Tuning the optical absorption of the gold nanoparticles in the NIR regime via a robust and repeatable method will improve many applications requiring large quantities of desired NIR absorbing nanoparticles.