Separation of nickel from copper in ammoniacal/ammonium carbonate solution using ACORGA M5640 by selective stripping

Separation of nickel from copper in ammoniacal/ammonium carbonate solution using ACORGA M5640 by selective stripping was carried out. The influence of equilibration time, equilibrium pH and extractant concentration on the extraction of both the metals was studied. It was found that the copper extraction equilibrium was reached in a shorter time than the nickel extraction equilibrium. Nickel extraction decreases above an equilibrium pH of 9.0, while the extraction of copper remains unaffected by the changes in the equilibrium pH range of 7–10. Co-extraction, ammonia scrubbing and the selective stripping of copper and nickel were performed for a solution containing 3 g/l each of copper and nickel and 60 g/l ammonium carbonate. The extraction and the percentage stripping of copper and nickel were almost quantitative.     

Mapping the total phosphorus concentration of biosolid amended surface soils using LANDSAT TM data

Conventional methods for soil sampling and analysis for soil variability in chemical characteristics are too time-consuming and expensive for multi-seasonal monitoring over large-scale areas. Hence, the objectives of this study are: 1) to determine changes in chemical concentrations of soils that are amended with treated sewage sludge; and 2) to determine if LANDSAT TM data can be used to map surface chemical characteristics of such amended soils. For this study, we selected two fields in NW Ohio, designated as F34 and F11, that had been applied with 34 and 11 ton acre^− 1 of biosolids, respectively. Soil samples from a total of 70 sampling locations across the two fields were collected one day prior to LANDSAT 5 overpass and were analyzed for several elemental concentrations. The accumulation of Ba, Cd, Cu, S and P were found to be significantly higher in the surface soils of field F34, compared to field F11. Regression equations were established to search for algorithms that could map these five elemental concentrations in the surface soils using six, dark-object-subtracted (DOS) LANDSAT TM bands and the 15 non-reciprocal spectral ratios derived from these six bands for the May 20, 2005, LANDSAT 5 TM image. Phosphorus (P) had the highest R² adjusted value (67.9%) among all five elements considered, and the resulting algorithm employed only spectral ratios. This model was successfully tested for robustness by applying it to another LANDSAT TM image obtained on June 5, 2005. Our results enabled us to conclude that LANDSAT TM imagery of bare-soil fields can be used to quantify and map the spatial variation of total phosphorous concentration in surface soils. This research has significant implications for identification and mapping of areas with high P, which is important for implementing and monitoring the best phosphorous management practices across the region.     

Toughness in synthetic and biological multilayered systems

Toughness in hard biological tissues is associated with fibrous or lamellar structures that deflect or stop growing cracks. In some cases, such as nacreous shell, protein interlayers absorb much of the crack energy. In other tissues, such as tooth enamel, the toughness derives from the mineral microstructure, and the small amount of residual protein apparently has little effect. There have been a number of efforts to make tough synthetic materials using layered structures. In this work, freeform fabrication has been used to make layered structures with a view to introducing similar toughness into brittle materials. Results are presented for epoxy-glass composites with glass fabric interlayers, porous alumina back-filled with aluminium metal, and layered glass-ceramic/silver materials.     

Holographically recorded photopolymer diffractive optical element for holographic and electronic speckle-pattern interferometry

A diffractive optical element is described that can be used to implement a very simple self-aligning electronic speckle-pattern interferometer and holographic interferometer that requires only a laser source and a camera in the optical setup.     

Can Agile and Traditional Systems Development Approaches Coexist? An Ambidextrous View

Emerging evidence seems to indicate that most systems development organizations are attempting to utilize both agile and traditional approaches. This study aims to understand the reasons organizations feel the need for this unlikely juxtaposition and the organizational challenges in sustaining the opposing cultures. Drawing on the extensive literature in organizational theory and management, we advocate ambidexterity as a viable solution to systems development organizations attempting to harness the benefits of both agile and traditional development.     

A study of nonisothermal austenite formation and decomposition in Fe-C-Mn alloys

Experiments using a hot-stage confocal scanning laser microscope (CSLM) have been carried out to observe phase transformations in two steels: Si-killed resulfurized Fe-0.38 wt pct C-1.43 wt pct Mn and Al-killed Fe-0.20 wt pct C-0.87 wt pct Mn. Austenite formation during continuous heating was investigated on the surface of samples that were etched to reveal the ferrite and pearlite regions. It was found that the austenite precipitated first at the pearlite colonies and subsequently in the ferrite phase. The measured advance rates of the γ/pearlite front were roughly twice those of the γ/α front and both interfaces were found to be curved. The γ/pearlite migration rate was found to be in qualitative agreement with published rate equations for isokinetic austenite formation where diffusion is the rate-limiting step. Austenite decomposition was studied during cooling. Widmanstätten ferrite laths precipitate as distinct colonies from the existing allotriomorphic ferrite phase but then also at MnS precipitates. The electron backscatter diffraction (EBSD) analysis showed that all of the laths in a particular colony exhibit similar orientation to one another but a slightly different orientation than the parent allotriomorph, supporting a sympathetic nucleation mechanism. The growth rate of the laths was found to vary widely within a range of 1.5 to 11 μm/s. The ferrite formation is finally halted by impingement with other advancing fronts. The results are presented in a phenomological discussion, with some quantitative analysis of the transformation kinetics.     

Enhanced layered segment trees: a pragmatic data structure for real-time processing of geometric objects

The data structure that is probably most used in the pattern recognition and image processing of geometric objects is the segment tree and its optimized variant, the “layered segment tree”. In all the versions currently known, except the work of Vaishnavi and Wood described later, these data structures do not operate in real time. Even in the latter scheme, although the structure can be implemented in real time and in an on-line fashion, the operation of insertion involves the sorting of the representations of the line segments in the tree. In essence, for all the reported algorithms, there is no known strategy to insert the segments one by one, other than the trivial strategy of processing them all together as in a batched-mode. In this paper, we present a strategy in which all the operations done on the tree can be done efficiently. Indeed, by improving the bottleneck, we prove that an arbitrary horizontal segment can be inserted into this data structure without invoking an expensive sorting process. We show that while this is accomplished by maintaining the same space and query complexity of the best-known algorithm, the version presented here is applicable to on-line real-time processing of line segments. The paper thus has applications in all areas of pattern recognition and image processing involving geometric objects.     

DIFFUSION COEFFICIENT OF OXYGEN IN LIQUIDS

The laminar dispersion of a solute in a capillary tube is used to measure diffusion coefficient of oxygen in liquids. A Polarographic type oxygen microelectrode is used to detect the pulse. Such a procedure overcomes the problems of measuring dissolved gases and makes it possible to apply this well known technique to oxygen-liquid systems. The results are in agreement with literature values     

Rapid thermal annealing effects on the photoluminescence properties of molecular beam epitaxy-grown GaIn(N)As quantum wells with Ga(N)As spacers and barriers

This article describes the effects of rapid thermal annealing (RTA) on the photoluminescence (PL) emission from a series of GaIn(N)As quantum wells. Indium compositions of both 20% and 32% were examined with nominal N compositions of 1% or 2%. The N location was varied within our quantum structure, which can be divided into three regions: (1) quantum well, (2) Ga(N)As spacer layers at the barrier-to-well interface and well-to-barrier interface, and (3) barriers surrounding each quantum well. Eight combinations of samples were examined with varying In content, Ga(N)As spacer layer thickness, N content, and N location in the structure. In the best cases, the presence of these Ga(N)As spacer layers improves the PL properties, due to annealing, with a reduction in the emission wavelength blueshift by ～400 Å, a reduction of the decrease in the full-width at half-maximum (FWHM) by ～5 meV, and a threefold reduction of the increase in integrated intensity. It was also observed that relocating N from the quantum wells to the barriers produces a comparable emission wavelength both before and after annealing. Our results further show that the composition of incorporated N in the material is most influential during the stages of RTA in which relatively small amounts of thermal energy is present from our lower annealing times and temperatures. Hence, we believe a low thermal-energy anneal is responsible for the recovery of the plasma-related crystal damage that was incurred during its growth. However, the In composition in the quantum well is most influential during the latter stages of thermal annealing, at increased times and temperatures, where the wavelength blueshift was roughly independent of the amount of incorporated N. As a result, our investigations into the effects of RTA on the PL properties support other reports that suggest the wavelength blueshift is not due to N diffusion.