Structural, Vibrational and Thermodynamic Properties of AgnCu34-n Nanoparticles

We report results of a systematic study of structural, vibrational and thermodynamical properties of 34-atom bimetallic nanoparticles from the AgnCu34-n family using model interaction potentials as derived from the embedded atom method and in the harmonic approximation of lattice dynamics. Systematic trends in the bond length and dynamical properties can be explained largely on arguments based on local coordination and elemental environment. Thus increase in the number of silver atoms in a given neighborhood introduces a monotonic increase in bond length while increase of the copper content does the reverse. Moreover, based on bond lengths of the lowest coordinated (6 and 8) copper atoms with their nearest neighbors (Cu atoms), we find that the nanoparticles divide into two groups with average bond length either close to (~ 2.58 A) or smaller (~ 2.48 A) than that in bulk copper, accompanied by characteristic features in their vibrational density of states. For the entire set of nanoparticles, vibrational modes are found above the bulk bands of copper/silver. Furthermore, a blue shift in the high frequency end with increasing number of copper atoms in the nanoparticles is traced to a shrinkage of bond lengths from bulk values. The vibrational densities of states at the low frequency end of the spectrum scale linearly with frequency as for single element nanoparticles, however, the effect is more pronounced for these nanoalloys. The Debye temperature was found to be about one third of that of the bulk for pure copper and silver nanoparticles with a non-linear increase with increasing number of copper atoms in the nanoalloys.Comment: 37 pages, 12 figure

On pricing of perishable assets with menu costs

Cataloged from PDF version of article.We consider dynamic pricing of perishable assets in the presence of price-sensitive renewal demand processes. Unlike the existing works in the literature, we explicitly incorporate non-negligible price change costs which reflects the revenue management practice more realistically. These costs are also known as menu costs in the economic literature. The objective is to maximize the discounted expected profit for an initial inventory of Q items by determining the selling prices dynamically. We employ a dynamic programming approach and formulate a model that captures the price– demand relationship. We establish some theoretical results on the properties of the problem at hand. Specifically, we establish the sufficient conditions under which the within-period profit is concave in the selling price and in the remaining shelf life and, furthermore, show the structure of the myopically and asymptotically optimal pricing policy. In a numerical study, we investigate the impact of various system parameters and, in particular, the existence of menu costs, on pricing decisions. We observe that ignoring menu costs may be significantly misleading for the implementation of revenue management. We also propose four implementable policy heuristics and examine their performances. Our findings support some results previously obtained in settings with continuous pricing and negligible price change costs; and, contradict some others. & 2009 Published by Elsevier B.V

Defatted yellow mealworm larvae (Tenebrio molitor l.) meal as possible alternative to fish meal in quail diets

The effects of replacing fish meal (FM) in the diet with defatted mealworm larvae meal (DMLM) on growth, carcass, and biochemical constituents of serum of Japanese quail chicks were investigated. A total of 600 unsexed one-day-old chicks were allotted to five dietary treatments with six replicates of 20 chicks each. The diets were formulated by replacing FM with DMLM at the levels of 25% (D25), 50% (D50), 75% (D75), and 100% (D100). The FM, D25 and D50 diets resulted in greater final bodyweight, higher bodyweight gain, and improved feed conversion ratio compared with the other diets. Diets that contained DMLM decreased the feed intake compared with the FM diet. The FM and D25 diets increased the hot and cold carcass yields compared with the other diets, whereas the D75 and D100 diets significantly enhanced the relative weight of the small intestine and abdominal fat compared with FM, D25, and D50. The replacement of FM with DMLM reduced the serum globulin, total cholesterol and triglyceride levels, and the albumin to globulin ratio significantly. The best protein and energy efficiency ratios and European efficiency factor were obtained with the D25 and D50 diets. In conclusion, the replacement of FM with DMLM at the levels of 25% and 50% produced positive results in growth performance, in serum albumin to globulin ratio, and in nutrient use efficiency in quail.Keywords: performance, serum biochemistry, slaughterin

Analysis of forest product trade relationships between Turkey and European Union member states

The countries have needed to strengthen their trade relationships in the face of increasing competition conditions with globalization and a lot of unions emerged all over the world. The European Union, remaining in the foreground as an economical, commercial and political factor in these unions, possesses considerable influence, which a lot of countries want to be involved in. Turkey, being in the European integration process, looks for a place in European Union (EU) with its own resources and production power. Production and foreign trade data of the forest products industry, being among Turkey’s important sectors, were compared with 25 different EU countries by using hierarchical cluster analysis, and Turkey’s trade relationship was determined. The production amounts, import and exportamounts and the values, between 2002 and 2006, belonging to the EU member countries and Turkey were used. It has been found that all countries could be divided into nine different groups according tocountries’ forest products industry structures. Competition advantage is experienced in the board sector but not in the paper and lumber sectors. The forest products industry sectors of Turkey have the capacity to compete with EU countries

Robust Cassie State of Wetting in Transparent Superhydrophobic Coatings

Cataloged from PDF version of article.This paper investigates the stability of the Cassie state of wetting in transparent superhydrophobic coatings by comparing a single-layer microporous coating with a double-layer micro/nanoporous coating. Increasing pressure resistance of superhydrophobic coatings is of interest for practical use because high external pressures may be exerted on surfaces during operation. The Cassie state stability against the external pressure of coatings was investigated by squeezing droplets sitting on surfaces with a hydrophobic plate. Droplets on the single-layer coating transformed to the Wenzel state and pinned to the surface after squeezing, whereas droplets on the double-layer micro/nanoporous coating preserved the Cassie state and rolled off the surface easily. In addition, the contact angle and contact-line diameter of water droplets during evaporation from surfaces were in situ investigated to further understand the stability of coatings against Wenzel transition. A droplet on a microporous coating gradually transformed to the Wenzel state and lost its spherical shape as the droplet volume decreased (i.e., the internal pressure of the droplet increased). The contact line of the droplet during evaporation remained almost unchanged. In contrast, a water droplet on a double-layer surface preserved its spherical shape even at the last stages of the evaporation process, where pressure differences as high as a few thousand pascals were generated. For this case, the droplet contact line retracted during evaporation and the droplet recovered the initial water contact angle. The demonstrated method for the preparation of robust transparent superhydrophobic coatings is promising for outdoor applications such as self-cleaning cover glasses for solar cells and nonwetting windows

The involvement of centralized and distributed processes in sub-second time interval adaptation: an ERP investigation of apparent motion

Accumulating evidence suggests that the timing of brief stationary sounds affects visual motion perception. Recent studies have shown that auditory time interval can alter apparent motion perception not only through concurrent stimulation but also through brief adaptation. The adaptation after-effects for auditory time intervals was found to be similar to those for visual time intervals, suggesting the involvement of a central timing mechanism. To understand the nature of cortical processes underlying such after-effects, we adapted observers to different time intervals using either brief sounds or visual flashes and examined the evoked activity to the subsequently presented visual apparent motion. Both auditory and visual time interval adaptation led to significant changes in the ERPs elicited by the apparent motion. However, the changes induced by each modality were in the opposite direction. Also, they mainly occurred in different time windows and clustered over distinct scalp sites. The effects of auditory time interval adaptation were centred over parietal and parieto-central electrodes while the visual adaptation effects were mostly over occipital and parieto-occipital regions. Moreover, the changes were much more salient when sounds were used during the adaptation phase. Taken together, our findings within the context of visual motion point to auditory dominance in the temporal domain and highlight the distinct nature of the sensory processes involved in auditory and visual time interval adaptation. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Lt