CFRP Rehabilitation of Concrete Frame Joints with Inadequate Shear and Anchorage Details

The research presented in this study involves full-scale experimental evaluation of carbon fiber-reinforced polymer (CFRP) rehabilitation for existing beam-column joints designed for gravity load with common pre-1970s deficient reinforcement details when subjected to cyclic loading. Numerous studies have demonstrated effectiveness of externally bonded fiber-reinforced polymer (FRP) materials for retrofitting the deteriorating RC structures. Although these materials are widely used in bridges, their applications in buildings have been somewhat limited. In particular, the experimental investigations on external FRP retrofit of deficient beam-column joints have not thoroughly been investigated and they are mainly on scaled-down specimens. The failure of these subassemblies, which possess lack of shear reinforcement within the joint core and shortly embedded positive beam reinforcement, would possibly result in catastrophic collapse of reinforced concrete frame structure during an earthquake event. Recognizing the urgent need to upgrade these structural subassemblies, the current investigation uses CFRP retrofit techniques to enhance the performance of such deficient joints. Experimental variables studied entail the developed CFRP retrofit configurations, and magnitude of the applied column axial load. Comparative analysis of the lateral loads versus drift hysteresis loops, stiffness degradation, and total dissipated energy curves of three as-built and three corresponding CFRP-retrofitted RC joints revealed that significant improvement in the shear capacity of the upgraded joints occurred. More importantly, the slippage of short embedded beam positive reinforcement into the joint was substantially controlled due to the developed CFRP retrofit. The results demonstrate the effectiveness of CFRP retrofit configurations in enhancing the structural performance of actual size connections.     

An effective wavelet-based feature extraction method for classification of power quality disturbance signals

This paper presents a wavelet norm entropy-based effective feature extraction method for power quality (PQ) disturbance classification problem. The disturbance classification schema is performed with wavelet-neural network (WNN). It performs a feature extraction and a classification algorithm composed of a wavelet feature extractor based on norm entropy and a classifier based on a multi-layer perceptron. The PQ signals used in this study are seven types. The performance of this classifier is evaluated by using total 2800 PQ disturbance signals which are generated the based model. The classification performance of different wavelet family for the proposed algorithm is tested. Sensitivity of WNN under different noise conditions which are different levels of noises with the signal to noise ratio is investigated. The rate of average correct classification is about 92.5% for the different PQ disturbance signals under noise conditions.     

Severe self-injurious behavior: The problem of clinical control.

Describes the long-term treatment program and follow-up of a case of chronic, severe, multiple self-injurious behavior. The intensity, frequency, and multiplicity of self-injurious behavior in a boy 1st seen at age 61/2 yrs is unparalleled in the literature. Treatment spanned 10 mo and more than 1,000 therapy hrs. Contingent electric shock and differential reinforcement of other behavior were the primary techniques utilized. The specifics of the punishment and reinforcement contingencies were modified throughout the program as a function of the behavior, thereby allowing for evaluation of the various components of the treatment procedures. Although initial results were only partially successful, total suppression was eventually achieved in the laboratory setting. The procedures described for extending this control to the natural environment proved only moderately successful. The technical, ethical, and theoretical issues concerning the treatment of severe self-injurious behavior are discussed. It is suggested that the extrapolation of laboratory evidence to the natural setting is premature in the case of severe self-injurious behavior. Suggested criteria for the assessment of successful clinical treatment of self-injurious behavior are offered. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Near ground propagation model for pine tree forest environment

A propagation model experimentally derived from both free space and near ground plane earth path loss models for pine tree forest with foliage depth lower than 400 m has been proposed. It is a piecewise model taking foliage depth of 200 m as a boundary. The model is compared with several well-known models, namely Weissberger, ITU-R and COST235. Different from other models, the proposed one takes into account trunk height gain k. Observed average error is about 6 dB for proposed model whereas it is about 32 dB, 16 dB and 20 dB for COST235, Weissberger and ITU-R models, respectively. Also, it is observed that COST235 estimates the highest path loss among the models and it has the highest absolute errors especially in a forest with low foliage density.     

Prevention of phagosome-lysosome fusion in cultured macrophages by sulfatides of Mycobacterium tuberculosis

Intracellular parasites (e.g., Mycobacterium tuberculosis, Toxoplasma gondii, and some Chlamydiae) may promote their survival within the host by acting from within phagosomes to prevent phagolysosome formation, thus avoiding exposure to the lysosomal hydrolases. The present studies demonstrate that when sulfatides of M. tuberculosis (anionic trehalose glycolipids largely responsible for the neutral red reactivity of virulent strains) are administered to cultured mouse peritoneal macrophages, they accumulate in the secondary lysosomes, which are rendered incompetent for fusion with phagosomes containing suitable target particles such as viable yeasts. This antifusion effect is also exhibited when small amounts of sulfatide are introduced directly into phagosomes by attachment to the target yeasts prior to their ingestion. The sulfatides evidently exert a selective inhibitory influence on membrane fusion, analogous to what occurs typically when macrophage cultures are infected with tubercle bacilli. This effect may be due to ionic interaction between the polyanionic micelles of bacterial sulfatide and organelle membranes, modifying the latter and inducing dysfunction.     

A problem space algorithm for single machine weighted tardiness problems

We propose a problem space genetic algorithm to solve single machine total weighted tardiness scheduling problems. The proposed algorithm utilizes global and time-dependent local dominance rules to improve the neighborhood structure of the search space. They are also a powerful exploitation (intensifying) tool since the global optimum is one of the local optimum solutions. Furthermore, the problem space search method significantly enhances the exploration (diversification) capability of the genetic algorithm. In summary, we can improve both solution quality and robustness over the other local search algorithms reported in the literature.     

America's love affair with technology: The transformation of sexuality and the self over the 20th century.

This article is an attempt to explore the impact of science and technology on the nature of experience and sense of self, with a focus on changing conceptions of the body, sexuality, and privacy. Although Freud and early psychoanalysts were pivotal in the application of science to private life and bringing sexuality to a public forum, the shift to a relational emphasis within the field, particularly in America, paved the way for the ascendance of the more technologically oriented sex therapy. The author suggests that the technological innovations of the cyberage have altered fundamental processes of perception and experience, conflating private and public, and changing subjective sense of self, the body, sexuality, and reality, posing new theoretical and clinical challenges for psychoanalysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Solar cells from carbon

A photovoltaic device, of the Schottky-barrier variety, has been fabricated from pure buckminsterfullerene and silver. The paper presents, as motivation for this work, a number of reasons why fullerenes may turn out to be excellent materials for solar cell fabrication. A summary is given of the experimental techniques employed and the results obtained thus far.     

On the deuterium quadrupole coupling constant of H-doped Y---Ba---Cu---O systems

The ²H quadrupole coupling constant e²qQ/h and asymmetry parameter η were measured for deuterium-doped Y₂BaCuO₅ (green phase) where x=0.31 and 0.61 in H_xY₂BaCuO₅ and at temperatures of 180, 300 and 360 K. The values are e²qQ/h = 235 ± 20 kHz and η = 0.05 ± 0.05, independent of x and the temperature. These results, together with previously measured quadrupole coupling constants of other hydrogen-doped Y---Ba---Cu---O compounds, are correlated with IR stretching frequencies of these compounds and support the model that the hydrogen forms an O---H bond.     

Efficient and Thermally Stable Wide Bandgap Perovskite Solar Cells by Dual-Source Vacuum Deposition

Wide bandgap perovskites are being widely studied in view of their potential applications in tandem devices and other semitransparent photovoltaics. Vacuum deposition of perovskite thin films is advantageous as it allows the fabrication of multilayer devices, fine control over thickness and purity, and it can be upscaled to meet production needs. However, the vacuum processing of multicomponent perovskites (typically used to achieve wide bandgaps) is not straightforward, because one needs to simultaneously control several thermal sources during the deposition. Here a simplified dual-source vacuum deposition method to obtain wide bandgap perovskite films is shown. The solar cells obtained with these materials have similar or even larger efficiency as those including multiple A-cations, but are much more thermally stable, up to 3500 h at 85 °C for a perovskite with a bandgap of 1.64 eV. With optimized thickness, record efficiency of >19% and semitransparent devices with stabilized power output in excess of 17% are achieved.