Superior Thermoelectric Performance of Textured Ca3Co4−xO9+δ Ceramic Nanoribbons

Calcium cobaltite Ca₃Co_4−xO_9+δ (CCO) is a promising p-type thermoelectric (TE) material for high-temperature applications in air. The grains of the material exhibit strong anisotropic properties, making texturing and nanostructuring mostly favored to improve thermoelectric performance. On the one hand multitude of interfaces are needed within the bulk material to create reflecting surfaces that can lower the thermal conductivity. On the other hand, low residual porosity is needed to improve the contact between grains and raise the electrical conductivity. In this study, CCO fibers with 100% flat cross sections in a stacked, compact form are electrospun. Then the grains within the nanoribbons in the plane of the fibers are grown. Finally, the nanoribbons are electrospun into a textured ceramic that features simultaneously a high electrical conductivity of 177 S cm⁻¹ and an immensely enhanced Seebeck coefficient of 200 µV K⁻¹ at 1073 K are assembled. The power factor of 4.68 µW cm⁻¹ K⁻² at 1073 K in air surpasses all previous CCO TE performances of nanofiber ceramics by a factor of two. Given the relatively high power factor combined with low thermal conductivity, a relatively large figure-of-merit of 0.3 at 873 K in the air for the textured nanoribbon ceramic is obtained.     

Attenuation of cocaine kindling by 7-nitroindazole, an inhibitor of brain nitric oxide synthase

Recent studies suggest the involvement of the N-methyl-D-aspartate (NMDA) type of glutamate receptors and nitric oxide synthase (NOS) in the process of increased sensitivity to the convulsive effect of cocaine ("cocaine kindling"). The present study was undertaken to analyze the various behavioral stages in the development of cocaine kindling and to investigate the effect of 7-nitroindazole (7-NI), a relatively selective inhibitor of the neuronal NOS isoform, on the induction and expression of sensitization to the convulsive effect of cocaine. Also, the effect of 7-NI on responses produced by acute systemic administration of cocaine or N-methyl-D,L-aspartate (NMDLA) was investigated. Cocaine kindling was assessed on a five-stage scale following the administration of a sub-convulsant dose of the drug (35 mg/kg/day; i.p.) to Swiss Webster mice for 10 days. Stage 5 seizures developed following the 9th day of cocaine administration. Pre-treatment with 7-NI (25 mg/kg/day; i.p.) 15 min before cocaine for 10 days completely prevented the appearance of stage 4 and 5 seizures, and it significantly attenuated stage 3 behavior in response to a challenge cocaine dose (35 mg/kg) given either 24 hr or 10 days after 7-NI/cocaine administration was stopped. A single injection of 7-NI (25 mg/kg; i.p.) completely prevented the expression of cocaine kindled seizures. Whereas 7-NI had no effect on the responses elicited by acute cocaine administration (60 mg/kg; i.p.), this agent partially attenuated the effects induced by systemic administration of the NMDA receptor agonist NMDLA (250 mg/kg; i.p.). The present study indicates that 7-NI attenuates both the induction and expression of sensitization to the convulsive effect of cocaine. The findings that 7-NI attenuated cocaine kindling and partially blocked the effects produced by activation of the NMDA receptor, but not the effects induced by acute cocaine administration, support the role of the NMDA receptor and brain NOS in the development of cocaine kindling rather than in the acute effects of the drug.     

Complexity of the consistency problem for certain Post classes

The complexity of the consistency problem for several important classes of Boolean functions is analyzed. The classes of functions under investigation are those which are closed under function composition or superposition. Several of these so-called Post classes are considered within the context of machine learning with an application to breast cancer diagnosis. The considered Post classes furnish a user-selectable measure of reliability. It is shown that for realistic situations which may arise in practice, the consistency problem for these classes of functions is polynomial-time solvable.     

Perceptual Issues in Music Pattern Recognition: Complexity of Rhythm and Key Finding

We consider several perceptual issues in the context of machine recognition ofmusic patterns. It is argued that a successful implementation of a musicrecognition system must incorporate perceptual information and error criteria.We discuss several measures of rhythm complexity which are used fordetermining relative weights of pitch and rhythm errors. Then, a new methodfor determining a localized tonal context is proposed. This method is based onempirically derived key distances. The generated key assignments are then usedto construct the perceptual pitch error criterion which is based on noterelatedness ratings obtained from experiments with human listeners.     

Workload, control, and social support effects on serum lipids: A longitudinal study among apparently healthy employed adults.

The authors investigated the direct and interactive effects of the job demand– control–support (JDC-S) model’s components on subsequent changes in high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides (TRI) separately for male and female employees. In contrast to all 14 past studies on these relationships, the authors used a longitudinal design. Study participants (N = 1,137, 66% men) were all apparently healthy employees who underwent a routine health check at 2 points in time (Time 1 and Time 2) about 22 months apart. In these analyses, the authors controlled for the Time 1 level of each criterion and for other confounders. Most of the direct and moderating effects found did not support the predictions of the JDC-S model; this finding is in agreement with the majority of past cross-sectional studies. The authors did not find any evidence supporting the existence of a reverse causation for either of the components of the JDC-S model. The authors suggest that serum lipids may not be a physiological mechanism mediating the effects of the JDC-S model on atherosclerotic diseases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decision support system for multiproject scheduling of resources in blood collection programmes

A model of a repetitive multiproject management is introduced that includes uncertainties in activity durations, and the corresponding quantities of resources needed. Following the convention, a project is viewed here as a network of related activities aimed at the accomplishment of a predetermined objective at a given deadline. A project has a starting point in time and a preplanned completion point and so does each activity within it. The structural and operational characteristics described here are drawn from organization and management theories and used to describe project organization. This is demonstrated by means of field data gathered from a sample of ‘bloodmobile projects’ - an organized effort for the collection of blood donations in support of medical needs.     

Boron nitride coatings of steel and graphite produced with a low pressure r.f. plasma

Boron nitride (BN) coatings were deposited onto die steel and graphite substrates with a low pressure r.f. plasma. The coatings were deposited onto substrates at temperatures of 550–620 °C from a gas mixture of argon, NH₃ and BCl₃. X-ray diffraction and scanning electron microscopy were employed to identify and to characterize the coatings. The coatings are mostly amorphous; however, the existence of small amounts of hexagonal BN was identified. The influence on the growth rate of the deposition time and the pressure in the reactor is described.     

Defending the beauty of the Invariance Principle

Customary stability analysis methods for nonlinear nonautonomous systems seem to require a strict condition of uniform continuity. Although extensions of LaSalle’s Invariance Principle to nonautonomous systems that mitigate this condition have been available for a long time, they have remained surprisingly unknown or open to misinterpretations. The large scope of the Principle might have misled the prospective users and its application to Control problems has been received with amazing yet clear uneasiness. Counterexamples have been used in order to claim that the Invariance Principle cannot be applied to nonlinear nonautonomous systems. Because the original formulation of the Invariance Principle still imposes conditions that are not necessarily needed, this paper presents a new Invariance Principle that further mitigates previous conditions and thus further expands the scope of stability analysis. A brief comparative review of various alternatives to stability analysis of nonautonomous nonlinear systems and their implications is also presented in order to illustrate that thorough analysis of same examples may actually confirm the efficiency of the Invariance Principle approach when dealing with stability of nonautonomous nonlinear systems problems that may look difficult or even unsolvable otherwise.     

Kernel density estimation with adaptive varying window size

A new method of kernel density estimation with a varying adaptive window size is proposed. It is based on the so-called intersection of confidence intervals (ICI) rule. Several examples of the proposed method are given for different types of densities and the quality of the adaptive density estimate is assessed by means of numerical simulations.