The coating of cadmium compounds with copper compounds

Fine particles of cadmium carbonate (CdCO₃) were prepared by heating aqueous solutions containing dissolved urea and cadmium sulfate at 85°C for 1 h. Effect of the composition of the reactant mixture on the morphology of the precipitated particles was investigated. It was found that the cadmium sulfate content of the reactant mixture significantly affected the shape and size of the precipitated particles. At certain range of reactant mixture composition, cauliflower-shaped uniform particles were obtained. The later particles were coated with basic copper carbonate (Cu₂(OH)₂CO₃) by heating aqueous dispersions, containing CdCO₃ particles, copper (II) nitrate, and urea at 85°C for various periods of time with constant stirring. The coating process was found sensitive to the experimental conditions and in most of the trials; mixtures of the coated and coating precursor particles were obtained. As such, extensive optimizations were carried out and conditions were established for the production of uniformly coated particles.On calcination at 700°C for 1 h, the CdCO₃ particles converted into CdO, whereas the coated particles (CdCO_{3 (core)}/Cu₂(OH)₂CO_{3 (coating)} transformed into CdO_(core)/CuO_(coating)) without sintering. In the coated particles, the core and coating materials stayed mutually inert during the calcination reaction and independently converted into their respective oxides.All the calcined and uncalcined products were characterized by various physical and chemical methods.     

Making combination drawing methods more efficient by controlling tool microroughness

Results are presented from extensive comparison studies of drawing operations performed with the use of drawplates whose working surfaces have an irregular or regular microroughness. Regularizing the microroughness of the working part of the drawplate makes it possible to control the dimensional accuracy of the resulting products within broad ranges of values.     

An open-source multi-DOF articulated robotic educational platform for autonomous object manipulation

This research presents an autonomous robotic framework for academic, vocational and training purpose. The platform is centred on a 6 Degree Of Freedom (DOF) serial robotic arm. The kinematic and dynamic models of the robot have been derived to facilitate controller design. An on-board camera to scan the arm workspace permits autonomous applications development. The sensory system consists of position feedback from each joint of the robot and a force sensor mounted at the arm gripper. External devices can be interfaced with the platform through digital and analog I/O ports of the robot controller. To enhance the learning outcome for beginners, higher level commands have been provided. Advanced users can tailor the platform by exploiting the open-source custom-developed hardware and software architectures. The efficacy of the proposed platform has been demonstrated by implementing two experiments; autonomous sorting of objects and controller design. The proposed platform finds its potential to teach technical courses (like Robotics, Control, Electronics, Image-processing and Computer vision) and to implement and validate advanced algorithms for object manipulation and grasping, trajectory generation, path planning, etc. It can also be employed in an industrial environment to test various strategies prior to their execution on actual manipulators.     

Transport of phosphorus forms and of nitrate through a clay soil under grass and cereal production

Many nutrients are lost from soil to water viatile drains. However, there are very few reliable studies of such phosphorus(P)losses under Swedish agriculture practices, especially in connection tofertiliser and slurry applications and related to nutrient balances. Tile drainlosses were measured from nine experimental plots in south-west Sweden; fourplots were measured for 7 years and five plots for 2–3 years. Cereals,mainly spring barley (Hordeum vulgare, L.) and oats(Avena sativa, L.), were grown in six plots, while oneplotwas cultivated with grass, timothy (Phleum pratense L.)andmeadow fescue (Festuca pratensis, L.), one with lucerne(Medicago sativa, L.) and meadow fescue (F.pratensis, L.), and the last one was a set-aside withgrass (Lolium perenne, L. and Trifoliumrepens, L.) that was neither fertilised nor used for crop removal.Attention was paid to the forms in which P was transported to water since thishas important ecological implications. Average losses of particulate P (PP)fromthe set-aside land was significantly lower than from the cerealproduction, but the average losses of soluble reactive P (SRP) and dissolvednonreactive P (DUP) were the same. Average loss of PP from the grass ley during 3years (0.09 kg per ha^–1 y^–1) wassignificantly less than the losses from cereal production. Total P loss of 0.3kg per ha^–1 y^–1 was equal to the averagelossfrom the Swedish monitoring network of observation fields. Compared to theaverage nitrate-nitrogen (NO₃-N) leaching, which was 7 kg perha^–1 y^–1 from cereals, the NO₃-Nleaching was very low from the plots with lucerne-grass and set-aside.After applying and directly ploughing in 80 kg ha^–1 ofsuperphosphate for cereal production in November 1998, 0.6–1.8 kgSRP ha^–1 y^–1 was lost through the drain tiles.Surface application of cattle slurry in spring 1999 to the grass ley alsoresulted in a very pronounced increased base level of SRP. This paper documentsthe importance of applying slurry during dry conditions and of placingfertiliser into the soil according to crop requirements in the time perspectiveof one year.     

An efficient recommender system algorithm using trust data

The Journal of Supercomputing - Smart services are a concept that provides services to the citizens in an efficient manner. The online shopping and recommender system can play an important role for...     

Intelligent control systems. II. Design of self-organized robust knowledge bases in contingency control situations

Informational technology for design of robust knowledge bases based on discovery synergetic effect of their self-organization in contingencies is developed. The principle of minimum of information entropy used in quantum algorithm guarantees the necessary condition of self-organization, the minimum of required initial information in learning signals; thermodynamic minimum criterion of the new measure of generalized entropy production provides sufficient condition of self-organization, robustness of control processes. In risky conditions and contingencies, the optimization of knowledge bases according to information-thermodynamic criteria, using the quantum algorithm of self-organization, provides invariant real-time achieving of the control objective with required robustness level of an intelligent control system. Example of efficient simulation of self-organization of robust knowledge bases in an intelligent control system of dynamically unstable essentially nonlinear object in contingencies is given.     

The effect of axisymmetric two-dimensional magnetic field on the configuration of vacuum-arc plasma

An experimental investigation is made of the effect of axisymmetric two-dimensional magnetic field on the forming of plasma and on the configuration of cathode spots in a vacuum-arc discharge. It is demonstrated that a magnetic field with a transverse (relative to the discharge axis) component has a significant effect on the shape of plasma column and on the rate of expansion of the cathode spot region. In a magnetic field, arc plasma has the form of truncated cone expanding toward the anode. The cathode spots take up a part of the cathode area which decreases with increasing magnetic field. Arguments are given in support of the assumption that the arrangement of cathode spots and the form of arc plasma are defined by the minimum principle similar to the Steinbeck principle. In so doing, the displacement of spots is caused by their emergence in a new region corresponding to a lower arc voltage. Also discussed is the mechanism associated with retrograde motion of cathode spot in view of the effect of azimuthal magnetic field on the axial component of current and of the effect of axial magnetic field on the azimuthal component of current.     

Ontology based E-learning framework: A personalized,adaptive and context aware model

Multimedia Tools and Applications - Enhancing the degree of learner productivity, one of the major challenges in E-Learning systems, may be catered through effective personalization, adaptivity and...     

Data broadcasting strategies for cognitive radio based AMI networks

Wireless Networks - Communication systems play an important role in smart grid (SG). Advanced Metering Infrastructure (AMI) is hybrid architecture in smart grid comprising of smart meters and...