Kinetics and mechanism of the hydrogen discharge on Ti in HCl-DMSO solutions

The kinetics of hydrogen discharge in solutions of HCl-DMSO is investigated within 10^?3 1 N HCl concentrations, in the presence of KClO₄ as supporting electrolyte. The cathodic slope is 0·120 V/decade for all solutions. The electrochemical reaction order with respect to the hydrogen ion concentration at E = ?0·6 V is found to be 0·52. The stoichiometric number is practically equal to 2. The experimental activation energy is 11·2 kcal/mole.The cathodic process is interpreted with the discharge reaction as rate determining step, followed by the adatom recombination reaction.     

Patch-based reconstruction of surfaces undergoing different types of deformations

We deal with the reconstruction of surfaces that deform under a variety of conditions. The deformation can range from no extension to a certain degree of extensibility. The deformed surface is reconstructed from a single image, given a 3D reference shape. This shape corresponds to the undeformed state of the surface and can be computed using any appropriate technique. In particular, we use homographies defined from two views of the surface. To proceed with the 3D reconstruction of the deformed surface, we assume that the deformations are locally homogeneous and that the overall surface deformation can be obtained by combining the local homogeneous deformations. For this purpose, the surface is split into small patches. For each patch, a mapping between the undeformed and the deformed shapes is computed. The mapping is specified by using the quadratic deformation model Fayad et al. (Proceedings of British Machine Vision Conference (BMVC), 2004). As a result, given the undeformed shape, we define an optimization procedure whose goal is to estimate the 3D positions of deformed points in each image. The optimization is performed on each patch, independently of the others. The experimental results show that this approach allows precise reconstruction of a wide class of real deformations.     

Developing Smart Grids Based on GPRS and ZigBee Technologies Using Queueing Modeling–Based Optimization Algorithm

Smart metering systems have become widespread around the world. RF mesh communication systems have contributed to the creation of smarter and more reliable power systems. This paper presents an algorithm for positioning GPRS concentrators to attain delay constraints for a ZigBee‐based mesh network. The proposed algorithm determines the number and placement of concentrators using integer linear programming and a queueing model for the given mesh network. The solutions given by the proposed algorithm are validated by verifying the communication network performance through simulations.     

A Custom Instruction Approach for Hardware and Software Implementations of Finite Field Arithmetic over \mathbb{F}_{{2^{{163}} }} using Gaussian Normal Bases

This paper presents a comprehensive analysis of the design of custom instructions in a reconfigurable hardware platform dedicated to accelerate arithmetic operations in the binary field $\mathbb{F}_{{2^{{163}} }} $ , using a Gaussian normal basis representation. The resulting platform is capable of running real applications, thus allowing a precise measurement of the execution overheads, and a fair comparison of the hardware and software speedups at several implementation levels. By using this approach, we determine which field operations (e.g., multiplication) are better suited to constrained environments, and which ones provide an enhanced performance in general-purpose systems. Experimental results reveal that by using our fastest field multiplier implemented as a custom instruction in a combined hardware/software approach, we accelerate point multiplication (the fundamental operation in Elliptic Curve Cryptography) over 126 times.     

Energetic and exergetic analyses of a dual-fuel diesel engine

The aim of this work is to investigate theoretically and experimentally the performance characteristics of a commercial diesel engine when operating in dual form: natural gas and diesel. The experimental facility (thermal system) is composed of a diesel engine coupled to an electronic generator with measuring sensor for temperature and pressure, air, natural gas and diesel flow meters, gas transducers, gas analyzer and power absorption system, constituted by an electric charge bank and its controlling system. For energetic and exergetic analysis of such dual engine, a mathematical model based on the thermodynamics concepts was developed. Numerical and experimental results concerning the effect of air conditions, the type and quantity of fuel used and the exhaustion gases over the engine performance and environmental impact are presented and analyzed. In this work, the diesel engine operated with powers ranging from 10 to 150 kW and replacement rates from 60% to 85%.     

New insights on the metabolism of ricinoleic acid in ruminants

Dairy goats were fed a total mixed ration with or without the inclusion of castor oil [40 g/kg of dry matter (DM)] to study the metabolism of ricinoleic acid (12-OH,cis-9–18:1). Ten goats, at 39.7 ± 4.0 d in milk, were individually penned and allocated at random to the 2 experimental diets. Goats were manually milked twice a day. Milk fatty acids (FA) were analyzed as methyl esters and hydroxyl groups were derivatized in trimethylsilyl ethers. Apart from ricinoleic acid, 6 FA were only detected in the milk of the castor oil group. Ricinoleic acid composed 0.3% of total FA in milk of the castor oil group, whereas the hydroxy-FA (8-OH-14:0, 10-OH-16:0, and 12-OH-18:0) and oxo-FA (8-oxo-14:0, 10-oxo-16:0, and 12-oxo-18:0) reached 7.5% of total FA in milk. We anticipate that these FA were derived from the metabolism of ricinoleic acid, although it was not clear if they were produced in the rumen or in the tissues. To confirm that, we conducted in vitro batch incubations repeated for 3 consecutive weeks with castor oil (40 g/kg of DM) and strained rumen fluid from 2 fistulated sheep. To examine the products formed over time, incubation tubes were stopped at 0, 6, 12, 24, 48, and 72 h. The results of the in vitro experiment showed that ricinoleic acid was metabolized in the rumen at a slow rate and the main products formed were 12-OH-18:0 and 12-oxo-18:0, by hydrogenation of the cis-9 double bond, followed by oxidation of the hydroxyl group, respectively. Our results suggest that the 12-OH-18:0 and 12-oxo-18:0 escape rumen and are further metabolized through partial β-oxidation in ruminant tissues. We propose that the 10-OH-16:0 and 8-OH-14:0 found in goat milk of the castor oil group are successive products of the β-oxidation of 12-OH-18:0, and the 10-oxo-16:0 and 8-oxo-14:0 are successive products of the 12-oxo-18:0 in tissues. Overall, our results indicate that ricinoleic acid is extensively metabolized in the rumen and tissues, producing mainly oxo- and hydroxy-FA that are further excreted in milk.     

Electrical Spin Injection from Ferromagnetic Nanocontacts into Nondegenerated Silicon at Low Temperatures

We present results on the magnetoresistance of the system Ni/Al₂O₃/Si/Al₂O₃/Ni fabricated in lateral nanostructures. The substrate n-type Si is a nondegenerated semiconductor with a doping level of 10¹⁵ cm^?3. The results are presented between 11 and 30 K, where the electrical resistivity of the semiconductor varies about 4 orders of magnitude. The reduction of magnetoresistance at 30 K is consistent with the standard theory for spin injection between a metal and a semiconductor. By fitting the data with $e^{ - t_{N} / L_{\mathrm{SD}}}$ , the diffusion condition, as a function of the channel length t _N , where the magnetoresistance takes place, we deduced the values of spin diffusion length L _SD and spin lifetime τ _s .     

Distinguishing nanowire and nanotube formation by the deposition current transients

ABSTRACT: High aspect ratio Ni nanowires (NWs) and nanotubes (NTs) were electrodeposited inside ordered arrays of self-assembled pores (approximately 50 nm in diameter and approximately 50 um in length) in anodic alumina templates by a potentiostatic method. The current transients monitored during each process allowed us to distinguish between NW and NT formation. The depositions were long enough for the deposited metal to reach the top of the template and form a continuous Ni film. The overfilling process was found to occur in two steps when depositing NWs and in a single step in the case of NTs. A comparative study of the morphological, structural, and magnetic properties of the Ni NWs and NTs was performed using scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometry, respectively.     

Effect of different forage sources on performance and feeding behavior of Holstein calves

One hundred seventy-nine Holstein male calves [44.7 kg of body weight (BW) and 8.3 d of age] participated in a series of 3 experiments to evaluate the effect of different forage sources on performance, apparent digestibility, and feeding behavior. Animals in each study were randomly assigned to 1 of 3 different dietary treatments: control (CON) calves were fed starter feed without any forage provision (this treatment was repeated in each of the 3 experiments), and the 2 other treatments consisted of the same starter feed plus a forage source: chopped alfalfa (AH) or rye-grass hay (RH) in the first study; chopped oat hay (OH) or chopped barley straw (BS) in the second study; corn silage (CS) or triticale silage (TS) in the third study. All calves were offered 2L of milk replacer (MR) at 12.5% dry matter (DM) twice daily via a bottle until 50 d of age, and 2L of MR at 12.5% DM during the week before weaning (57 d of age). The study finished when calves were 71 d old. Starter feed, MR, and forage intakes were recorded daily and BW weekly. Calves were individually housed and bedded with wood shavings. Compared with CON, animals receiving OH, TS, and BS consumed more starter feed (0.88 vs. 1.14, 1.17, 1.06 kg/d, respectively) and had greater average daily gain (0.72 vs. 0.93, 0.88, 0.88 kg/d, respectively). Animals in treatments RH, BS, CS, and TS consumed less forage (51 g/d) than AH (120 g/d) and OH (101 g/d) calves. Apparent organic matter, DM, and neutral detergent fiber digestibilities did not differ among treatments (81.5, 81.1, and 54.4%, respectively). Apparent crude protein digestibility was greater in RH, CS, and AH treatments than in CON (80.5 vs. 76.4%, respectively). Compared with CON calves, animals in the AH treatment spent less time eating starter feed and lying, animals in AH and RH treatments spent more time ruminating, with odds ratios (OR) of 5.24 and 5.40, respectively. The AH and RH calves devoted less time to performing nonnutritive oral behaviors (OR: 0.38 and 0.34, respectively), and TS calves tended to devote less time to perform nonnutritive oral behaviors (OR: 0.21) 1h after being offered MR and solid feed. In conclusion, free-choice provision of a forage source to young calves improves feed intake and performance without impairing digestibilities of DM, organic matter, crude protein, and neutral detergent fiber, and, depending on forage source, reduces nonnutritive oral behaviors and stimulates rumination.