A simple hourly all-sky solar radiation model based on meteorological parameters

An hourly solar radiation model for cloudy skies, based on meteorological data, was developed andtested. As a means of comparison, the SOLMET regression and Watt models were also tested. The present model was examined for individual cloud types using measured solar radiation to judge the effectiveness of the model in the presence of particular clouds.     

Preparation, morphology, and gas-sensing behavior of Cr/sub 2-x/Ti/sub x/O/sub 3+z/ thin films on standard silicon wafers

The effect of humidity on chromium titanium oxide (Cr/sub 2-x/Ti/sub x/O/sub 3+z/, CTO), on both baseline resistance and sensitivity, is small compared to SnO/sub 2/. This has been the key to development of thick-film sensors based on CTO, for detection of carbon monoxide and ammonia in synthetic air. Thin-film structures on silicon substrates offer the possibility to use fabricating, bonding and housing equipment and, hence, a low cost gas sensor production is possible. CTO thin-film sensors on silicon substrates use conventional photolithography, sputtering and evaporation techniques. A Ta/Pt resistance layer (25/200-nm thick) for heating the device to its operating temperature and interdigital electrodes are evaporated and structured on a silicon substrate which is covered by a 1-/spl mu/m SiO/sub 2/ insulating layer. The polycrystalline p-type CTO is deposited onto the electrodes by oxidizing reactive sputtering or evaporation of Cr/Ti-sandwich structures. The resulting sensors were characterized by means of energy dispersive X-ray analysis, secondary electron microscopy, and X-ray diffraction pattern. Also, gas responses toward NO/sub 2/, NH/sub 3/, CO and CH/sub 4/, and different humidity, were investigated.     

Using multi-modal 3D contours and their relations for vision and robotics

In this work, we make use of 3D contours and relations between them (namely, coplanarity, cocolority, distance and angle) for four different applications in the area of computer vision and vision-based robotics. Our multi-modal contour representation covers both geometric and appearance information. We show the potential of reasoning with global entities in the context of visual scene analysis for driver assistance, depth prediction, robotic grasping and grasp learning. We argue that, such 3D global reasoning processes complement widely-used 2D local approaches such as bag-of-features since 3D relations are invariant under camera transformations and 3D information can be directly linked to actions. We therefore stress the necessity of including both global and local features with different spatial dimensions within a representation. We also discuss the importance of an efficient use of the uncertainty associated with the features, relations, and their applicability in a given context.     

On the use of infrared thermography for the analysis of fatigue damage processes in welded joints

The paper presents an experimental approach for the analysis of localized fatigue damage processes during fatigue testing of welded steel structures by thermographic investigations of thermomechanical coupling phenomena. Special data processing of the recorded infrared sequences is proposed to separate linear and nonlinear damage-indicating effects. The method has been successfully applied to analyze the damage progress during fatigue testing of welded components. On the tested components localized damage processes could be observed as early as 10–30% of the total fatigue lifetime. The results confirm the high potential of the methodology for the determination of fatigue damage initiation. The technique provides a powerful experimental tool to investigate localized inhomogeneous damage and to analyze complex fatigue processes.     

Koutecky-Levich analysis applied to nanoparticle modified rotating disk electrodes： Electrocatalysis or misinterpretation？

The application of naive Koutecky-Levich analysis to micro- and nano-particle modified rotating disk electrodes of partially covered and non-planar geometry is critically analysed. Assuming strong overlap of the diffusion fields of the particles such that transport to the entire surface is time-independent and one-dimensional, the observed voltammetric response reflects an apparent electrochemical rate o constant koapp, equal to the true rate constant ko describing the redox reaction of interest on the surface of the nanoparticles and the ratio,ψ, of the total electroactive surface area to the geometric area of the rotating disk surface. It is demonstrated that Koutecky-Levich analysis is applicable and yields the expected plots of I-1 versus ω-1 where I is the current and ω is the rotation speed but that the values of the electrochemical rate constants inferred are thereof koapp, not ko. Thus, for ψ 〉 1 apparent electrocatalysis might be naively but wrongly inferred whereas for ψ 〈 1 the deduced electrochemical rate constant will be less than ko. Moreover, the effect of ψ on the observed rotating disk electrode voltammograms is significant, signalling the need for care in the overly simplistic application of Koutecky-Levich analysis to modified rotating electrodes, as is commonly applied for example in the analysis of possible oxygen reduction catalysts.     

The Role of Intravitreal Corticosteroids in the Treatment of DME: Predictive OCT Biomarkers

This work aims to summarize predictive biomarkers to guide treatment choice in DME. Intravitreal anti-VEGF is considered the gold standard treatment for centers involving DME, while intravitreal steroid treatment has been established as a second-line treatment in DME. However, more than 1/3 of the patients do not adequately respond to anti-VEGF treatment despite up to 4-weekly injections. Not surprisingly, insufficient response to anti-VEGF therapy has been linked to low-normal VEGF levels in the serum and aqueous humor. These patients may well benefit from an early switch to intravitreal steroid treatment. In these patients, morphological biomarkers visible in OCT may predict treatment response and guide treatment decisions. Namely, the presence of a large amount of retinal and choroidal hyperreflective foci, disruption of the outer retinal layers and other signs of chronicity such as intraretinal cysts extending into the outer retina and a lower choroidal vascular index are all signs suggestive of a favorable treatment response of steroids compared to anti-VEGF. This paper summarizes predictive biomarkers in DME in order to assist individual treatment decisions in DME. These markers will help to identify DME patients who may benefit from primary dexamethasone treatment or an early switch.     

Thermal dehydrochlorination of PVC in the presence of rubber seed oil

Dehydrochlorination rates of PVC in nitrogen atmosphere were determined in the presence of rubber seed oil (RSO), epoxidized rubber seed oil (ERSO), barium soap of rubber seed oil fatty acids and barium soap of epoxidized fatty acid of rubber seed oil. The initial rates of dehydrochlorination and the time required for the degradation to attain 1% conversion showed that the rubber seed oil derivatives exert a stabilizing effect on the degradation of PVC. The order of the stabilizing effect was found to be metal soaps of ERSO < metal soaps of RSO < ERSO < RSO.     

Grafting acrylonitrile and acrylic acid monomers on cellulosic materials

Graft copolymers of acrylonitrile and of acrylic acid monomers on cellulosic materials were obtained by use of ceric ion initiator in aqueous medium at a 50% (w/w) cellulose-monomer ratio. The variations of poly(acrylonitrile) grafts and of the efficiency of grafting with ceric ion concentration, and of poly(acrylic acid) grafts with temperature are examined. The dependence of water retention capacity of the grafted fibers with the graft level is reported.     

Trimetallic Mn‐Fe‐Ni Oxide Nanoparticles Supported on Multi‐Walled Carbon Nanotubes as High‐Performance Bifunctional ORR/OER Electrocatalyst in Alkaline Media

Discovering precious metal‐free electrocatalysts exhibiting high activity and stability toward both the oxygen reduction (ORR) and the oxygen evolution (OER) reactions remains one of the main challenges for the development of reversible oxygen electrodes in rechargeable metal–air batteries and reversible electrolyzer/fuel cell systems. Herein, a highly active OER catalyst, Fe_0.3Ni_0.7O_X supported on oxygen‐functionalized multi‐walled carbon nanotubes, is substantially activated into a bifunctional ORR/OER catalyst by means of additional incorporation of MnO_X. The carbon nanotube‐supported trimetallic (Mn‐Ni‐Fe) oxide catalyst achieves remarkably low ORR and OER overpotentials with a low reversible ORR/OER overvoltage of only 0.73 V, as well as selective reduction of O₂ predominantly to OH^?. It is shown by means of rotating disk electrode and rotating ring disk electrode voltammetry that the combination of earth‐abundant transition metal oxides leads to strong synergistic interactions modulating catalytic activity. The applicability of the prepared catalyst for reversible ORR/OER electrocatalysis is evaluated by means of a four‐electrode configuration cell assembly comprising an integrated two‐layer bifunctional ORR/OER electrode system with the individual layers dedicated for the ORR and the OER to prevent deactivation of the ORR activity as commonly observed in single‐layer bifunctional ORR/OER electrodes after OER polarization.