Nonlinear optical absorption of ZnO doped with copper nanoparticles in the picosecond and nanosecond pulse laser field

The nonlinear absorption of nanocomposite layers based on ZnO implanted with Cu+ ions with an energy of 160 keV in implantation doses of 10(16) and 10(17) ions/cm2 was investigated. The values of the nonlinear absorption coefficient were measured by the Z-scan method at a wavelength of 532 nm by use of nanosecond and picosecond laser pulses. Possible optical applications of these materials are discussed.     

Error rate performance analysis of coded free-space optical links over gamma-gamma atmospheric turbulence channels

Error control coding can be used over free-space optical (FSO) links to mitigate turbulence-induced fading. In this paper, we derive error performance bounds for coded FSO communication systems operating over atmospheric turbulence channels, considering the recently introduced gamma-gamma turbulence model. We derive a pairwise error probability (PEP) expression and then apply the transfer function technique in conjunction with the derived PEP to obtain upper bounds on the bit error rate. Simulation results are further demonstrated to confirm the analytical results.     

Advanced mathematical model for the passive direct borohydride/peroxide fuel cell

In the literature a mathematical model has been developed for the direct borohydride fuel cells by Verma et al. [1]. This model simply simulates the fuel cell system via kinetic mechanisms of the borohydride and oxygen. Their mathematical expression contains the activation losses caused by the oxidation of the borohydride and the concentration overpotential increased by the reduction of oxygen. In this study a direct borohydride/peroxide fuel cell has been constructed using hydrogen peroxide (H₂O₂) as oxidant instead of the oxygen. Therefore we created an advanced model for peroxide fuel cells, including the activation overpotential of the peroxide. The goal of our model is to provide the information about the peroxide reduction effect on the cell performance. Our comprehensive mathematical model has been developed by taking Verma’s model into account. KH₂O₂ used in the advanced model was calculated as 6.72 × 10⁻⁴ mol cm⁻² s⁻¹ by the cyclic voltammogram of Pt electrode in the acidic peroxide solution.     

Effect of cement type on the resistance of concrete against chloride penetration

In chloride containing environment, chloride permeability of concrete is an important parameter affecting the service life of concrete structures. The primary objective of this experimental study was to study the effect of cement types on the resistance of concrete against chloride penetration for given compressive strength classes. These cements included two different types of granulated blast-furnace slag cement (CEM III/A 32.5N and CEM III/A 42.5N), a sulfate resisting cement (SRC 32.5), and a Portland cement blended with fly ash; all of which compared to an ordinary Portland cement (CEM I 42.5R). For each binder type, four concretes at different strength classes were produced and as a result 20 mixtures were obtained. Rapid chloride ion penetration tests according to ASTM C 1202 were conducted. In addition, electrical resistivity and capillary water absorption tests were carried out. In order to characterize the concrete quality, compressive strength of the specimens were also obtained. The test results clearly demonstrated that the blast-furnace slag cements have the highest resistance against chloride penetration, while the pure Portland cement and sulfate resisting cement have the lowest resistance. Concretes produced with the sulfate resisting cement had substantially higher capillary sorption compared to other mixtures. Test results confirmed the strong relationship between the chloride permeability and electrical resistivity.     

Performance of self-compacting concrete containing different mineral admixtures

This paper presents experimental study on the properties of self-compacting concrete (SCC). Portland cement (PC) was replaced with fly ash (FA), granulated blast furnace slag (GBFS), limestone powder (LP), basalt powder (BP) and marble powder (MP) in various proportioning rates. The influence of mineral admixtures on the workability, compressive strength, ultrasonic pulse velocity, density and sulphate resistance of SCC was investigated. Sulphate resistance tests involved immersion in 10% magnesium sulphate and 10% sodium sulphate solutions for a period of 400 days. The degree of sulphate attack was evaluated using visual examination and reduction in compressive strength. The test results showed that among the mineral admixtures used, FA and GBFS significantly increased the workability and compressive strength of SCC mixtures. Replacing 25% of PC with FA resulted in a strength of more than 105 MPa at 400 days. Moreover, the presence of mineral admixtures had a beneficial effect on the strength loss due to sodium and magnesium sulphate attack. On the other hand, the best resistance to sodium and magnesium sulphate attacks was obtained from a combination of 40% GBFS with 60% PC.     

The Future of Human Activity Recognition: Deep Learning or Feature Engineering?

Neural Processing Letters - A significant gap exists in our knowledge of how domain-specific feature extraction compares to unsupervised feature learning in the latent space of a deep neural...     

The Synthesis and Characterization of Star Shaped Metal Complexes of Triazine Cored Schiff Bases: Their Thermal Decompositions and Magnetic Moment Values

Tripodal ligand III, 2,4,6-tris(4-hydroxybenzimino)-1,3,5-triazine, was synthesized by reacting melamine with 4-hydroxybenzaldehyde. (E)-4-Bromo-2-((2-bromoethylimino)-methyl)phenol VI was obtained by reaction of 5-bromo-2-hydroxybenzaldehyde and 2-bromoethanamine hydrochloride. Melamine cored tripodal Schiff base VII (H₃L) was synthesized by reacting III with VI. Tripodal metal complexes were obtained by reacting H₃L and transition metal salts. The complexes were characterized by elemental analyses, FT-IR, ¹H NMR and LC–MS spectroscopy, thermal analyses and magnetic measurements. Finally, metal ratios of the complexes were determined by atomic absorption spectroscopy. The complexes are square-planar low-spin (S = 1/2) Co(II), diamagnetic square-planar Ni(II), square-planar (S = 1/2) Cu(II) and diamagnetic tetrahedral Zn(II).     

Error rate performance of coded free-space optical links over strong turbulence channels

Error control coding can be used over free-space optical (FSO) links to mitigate turbulence-induced fading. We present error rate performance bounds for coded FSO communication systems operating over atmospheric turbulence channels, which are modeled as a correlated K distribution under strong turbulence conditions. We derive an upper bound on the pairwise error probability (PEP) and then apply the union-bound technique in conjunction with the derived PEP to obtain upper bounds on the bit error rate. Simulation results are further demonstrated to verify the analytical results.     

Influence of immediate post-therapy bone scintigraphy in the assessment of response to therapy in a case of nasopharyngeal carcinoma

We have conducted a retrospective study of deaths on a paediatric medical intensive care unit over a two-year period and reviewed similar series from outside the UK. There were 89 deaths out of 651 admission (13.7% mortality). In almost two-thirds of the cases death occurred with a decision to limit medical treatment or withdraw mechanical ventilation, implying that additional or further therapy was considered futile. We highlight this as a crucially important issue in the practice of intensive care. More comprehensive studies are needed to help clinicians derive consensus on what constitutes a futile intervention, and therefore when such an intervention should be withheld. This will help families and society better understand the limitations of intensive care.     

Bovine spongiform encephalopathy in Germany

Bovine spongiform encephalopathy (BSE) has been described as an epidemic central nervous disorder in cattle from the United Kingdom. The disease is thought to have emerged by an interspecies transmission of the scrapie agent of sheep to cattle, after feeding scrapie-contaminated meat and bone meal (MBM). The disease has caused substantial economic losses for the British cattle industry. Because of strict veterinary regulations for the import of adult British cattle by the European Union and for MBM by most of the member states the spread of BSE to continental Europe could be efficiently controlled, and only few cases have been described outside the UK. Here we report the first German case of BSE diagnosed in a Scottish Highland cow. The affected cow was imported into Germany before the import ban for cattle from the UK was implemented. BSE was confirmed by histopathology, immunohistochemistry, animal experiments, immunoblotting and by electron microscopic detection of scrapie-associated fibrils (SAFs).