Thermoelectric Effect Spectroscopy and Photoluminescence of High-Resistivity CdTe:In

Thermoelectric effect spectroscopy and photoluminescence techniques were used to study the defect levels in samples from three crystals of CdTe:In grown by the vertical gradient freeze method. The main goal of the investigation was to study defects, which strongly trap charge carriers or act as recombination centers in order to eliminate them from the technological process. The main difference among detecting and non-detecting samples was the absence of electron traps with a very high capture cross-section and energy 0.6 eV to 0.7 eV, which act as lifetime killers even at low concentrations. Recently published ab initio calculations show a complex of Te antisite and Cd vacancy within this energy range.     

Injectable collagen/α-tricalcium phosphate cement: collagen–mineral phase interactions and cell response

A bone inspired material was obtained by incorporating collagen in the liquid phase of an α-tricalcium phosphate cement, either in solubilized or in fibrilized form. This material was able to set in situ, giving rise to a calcium deficient hydroxyapatite (CDHA)/collagen composite. The morphology and distribution of collagen in the composite was shown to be strongly affected by the collagen pre-treatment. The interactions between collagen and the inorganic phase were assessed by FTIR. A red shift of the amide I band was indicative of calcium chelation by the collagen carbonyl groups. The rate of CDHA formation was not affected when diluted collagen solutions (1 mg/ml) were used, whereas injectability improved. The presence of solubilized collagen, even in low amount (1 %), increased cell adhesion and proliferation on the composites. Still in the absence of osteogenic medium, significant ALP activity was detected both in the inorganic and the collagen-containing cements. The maximum ALP activity was advanced in the collagen-containing cement as compared to the inorganic cement.     

Experimentelle Simulation der Oberflächenrissbildung beim Stranggießprozess mit Hilfe des IMC-B Versuchs

Continuous casting of steel free of surface cracks is still one of the major quality challenges in the whole steel production. The key roles for the phenomenon of surface cracking are played by the critical strain and the temperature-dependent material’s phenomena. The new In-Situ Characterization Bending (IMC-B) method will enable the investigation of the critical strains with respect to the cracking under the main continuous casting boundaries. This publication presents potential and interesting results of the IMC-B experiment.     

Secondary ketonization of primary alcohol over LaMn-based mixed oxides with perovskite-like structure

LaMnO₃-based mixed oxides with perovskite-like structure both bulk and supported on La–Al₂O₃, show high catalytic activity in dehydrogenation of n-butanol to an aldehyde, which then undergoes a secondary reaction to produce a symmetrical ketone. Partial substitution of Cu, V or Sr into LaMnO₃ structure does not destroy the perovskite-like structure and enables to control the acid–base surface properties. It allows linking up these qualitative and quantitative features with activity and selectivity of these materials. The degree of n-butanol conversion depends on the total concentration of basic and acidic sites. Selectivity to butyraldehyde can be related with the share of basic sites. Selectivity to dipropyl ketone is affected both by the acidity and concentration of acidic sites. LaMnO₃/La–Al₂O₃ seems to posses an optimum set of surface characteristics for the examined ketonization of a primary alcohol.     

Study of Conversion Coatings on Zinc Deposition Obtained from Low Pollution Solutions

The electrochemical engineering and operation of a pilot plant for the electrodeposition of Zn-Mn alloys is described in this paper. The time-averaged current density (hence c.d.) distribution on the wire and the time evolution of the bath composition are modelled and compared with experiment. Electrodeposition experiments were performed at different c.d.s on several hundred meters of steel wire; the composition of the coatings as a function of c.d. is predicted with a simple electrochemical model, also taking into account mass transport at the wire, and compared with experiment. Structural and functional properties of the coatings were studied, some effects of drawing on the coating properties were measured. The surface morphology of Zn-Mn coatings on steel wires was studied by SEM, their crystallographic structure was investigated by XRD and their in-depth composition by AES. Corrosion resistance in neutral and alkaline solutions and corrosion effects on tensile properties of the coated steel wire were measured.     

Do new SCI journals have a different national bias?

National shares of worldwide publications in the Science Citation Index (SCI) have shifted recently. The long-term decline in U.S. share accelerated in the mid-1990s, and now the EU has joined this decline. Not coincidentally, the shares of some countries have increased sharply, particularly those of China, S. Korea, Taiwan, and Singapore. Since the SCI constantly adds new journals, one reason might be that newly added journals were more favorable to them. To test this, the database was partitioned into “old journals” (added before 1995) and “new journals,” added afterward. The analysis was done for eight of the 20 fields of science defined by the National Science Indicator CD. In some fields, new journals were indeed much more favorable to the Asians. In some fields, however, new journals were actually more favorable to the U.S. In aggregate over the eight fields analyzed, the size of this effect was too small to account for much of the sharp changes in national shares. Furthermore tests between old and new journals find that differences in most fields are not statistically significant. The results provide evidence that the SCI can be used to accurately track national publication changes over time.     

Experimental Evidence of the Effect of Alloying Additions on the Stagnant Stage Length During Cyclic Partial Phase Transformations

Cyclic phase transformation experiments are performed in a series of Fe-C-xMn, Fe-C-Mn-xNi, and Fe-C-Mn-xCo alloys to study the effect of alloying elements on the length of the stagnant stage during a cyclic partial phase transformation in the austenite–ferrite two-phase region. The length of stagnant stage increases linearly with the increasing Mn or Ni concentration, while Co has no effect. It was experimentally proven that the effects of alloying elements on the length of stagnant stage are additive, and the experimental results matched the predictions of the local equilibrium model very well.     

Closed-loop control of hydraulic telescopic handler

Automatization is supposed to improve working conditions and safety in the construction industry, as it already did in manufacturing industries. This paper presents the development of a robotic control system for a commercially available hydraulic telescopic handler. The target application for the telescopic handler is semi-automated assembly of facade panels. The base handler was upgraded with two additional hydraulic axes, position sensors and closed-loop control system, while the original handler safety assurance mechanisms were preserved. The control approach is based on a PI controller with velocity feedforward and valve overlap compensation. The direct and inverse kinematic models of handler mechanism were developed to enable control of end-effector motion along a straight line in the Cartesian coordinate system. The motion performances were evaluated following the ISO 9283 standard with payload of 2000 kg. Results show the repeatability of positioning bellow 7.0 mm and the straight line tracking error smaller than 63 mm.