Catalytic Reduction of 4-Nitrobenzoic Acid by cis-[Rh(CO)2(Amine)2](PF6) Complexes Under Water–Gas Shift Reaction Conditions: Kinetics Study

Rhodium(I) complexes of the type, cis-[Rh(CO)₂(amine)₂](PF₆) where (amine = 3-picoline, 2-picoline, pyridine, 2,6-lutidina or 3,5-lutidine) dissolved in 80% aqueous amine solutions catalyzed the selective reduction of 4-nitrobenzoic acid to 4-aminobenzoic acid under CO atmosphere. The importance of these catalytic systems is their high chemo selectivity for the aromatic nitro group of the 4-nitrobenzoic acid with respect to the carboxylic group, allowing the production of the desired aromatic amine in high yields. The 4-aminobenzoic acid production depends on the nature of the coordinated amine. The Rh/3,5-lutidine system, the most active catalyst among tested, displays turnover frequencies for 4-aminobenzoic acid production of about 173 moles per mole Rh per day for [Rh] = 1 × 10^?4 mol, [4-nitrobenzoic acid] = 3.82 × 10^?3mol, 10 mL of 80% aqueous 3,5-lutidine, P(CO) = 0.9 atm at 100 °C. Analyses of kinetic results for the Rh/3,5-lutidine system show a first order dependence on 4-nitrobenzoic acid concentration, a non-linear dependence on CO pressure, a segmented Arrhenius plot and dependence on the nature of the reducing gas agent. These data are discussed in terms of a possible mechanism.     

Solvent extraction of uranium from acidic sulfate media by Alamine® 336: computer simulation and optimization of the flow‐sheets

BACKGROUND: A series of nine conventional and non‐conventional flow‐sheets have been considered for the recovery of uranium from acidic sulfate solution by liquid–liquid extraction with 0.146 mol L^?1 Alamine^® 336 in kerosene modified with 5% w/w 1‐tridecanol and stripping with a 199 g L^?1 Na₂CO₃ solution. The reference flow‐sheet was a classical counter‐current configuration with four mixers–settlers in the extraction stage and three mixers–settlers in the stripping stage. The others flow‐sheets possessing a total of eight mixers–settlers are unusual combined solvent extraction flow‐sheets with one or two independent extraction stripping loops and with one or two feed inlets. RESULTS: The configuration of the flow‐sheets strongly influences the extraction performance of the process depending on the working conditions (feed, stripping and solvent flow rates). The presence of two independent extraction–stripping loops may allow the delay of the saturation phenomenon encountered in the conventional flow‐sheet and thus, to operate at higher feed flow rates without loss of performance, as far as the residual fraction in the raffinate and the concentration factor in the stripping solution are concerned. Furthermore, the presence of a modification in the non‐conventional flow‐sheets with two independent extraction–stripping loops and two feed inlets leads to interesting configurations for uranium recovery from less concentrated solutions, such as heap leach solutions. CONCLUSION: The use of non‐conventional flow‐sheets is interesting as it allows the process of uranium (VI) recovery by liquid–liquid extraction to be improved. Copyright © 2009 Society of Chemical Industry     

Informatics support to medical diagnosis. General information obtained from a first structured contact with the patient

BACKGROUND: The methods and characteristics of clinical data gathered at the initial steps of development of a computerized system to aid medical diagnosis are reported. The objectives of the study were as follows: to describe the overall method and to set a framework for developing an intellectual model of the medical diagnosis procedure. MATERIAL AND METHODS: A structured medical interview and physical examination using an informatic program on PC compatible portable computers were completed in a sample 1,238 patients attending the outpatient clinics of our institution. Data obtained were compared with information in the patient's medical record taking as reference pattern the record of physicians in charge of the patients. Diagnosis were codified according to WHO International Classification of Diseases (ICD-9-CM). RESULTS: The distribution of symptoms and signs corresponding to the different organs and systems was analyzed. Each subdivision afforded a range of 1.3 to 3.9 abnormal findings per patient. A total of 3,571 diagnoses were codified for the whole group 1,238 patients with a mean (standard deviation) of 3 (2) diagnoses per patient (range 0-12). The distribution of diagnostic groups varied depending on the consideration of the main diagnosis or the concomitant diagnoses that defined the patient's clinical context. The most frequent main diagnoses included tumors, cardiovascular diseases, gastrointestinal disorders, and genitourinary tract diseases. CONCLUSIONS: As shown by results obtained in a sample of 1,238 patients, there is a very complex situation in clinical practice due to the simultaneous occurrence of several clinical patterns. This finding should be taken into account when developing clinical decision making support systems. The use of a structured medical interview or a structured and standard medical visit may be an adequate tool to clarify this matter and to contribute to standardization of clinical concepts and situations.     

Evolution of available lysine and furosine contents in milk‐based infant formulas throughout the shelf‐life storage period

The evolution of the Maillard reaction (MR) by measuring the available lysine and furosine (FUR) contents in adapted and follow‐up powdered milk‐based infant formulas over the shelf‐life storage period, at 20 and 37 °C, was studied. Available lysine and FUR contents were determined by fluorimetry and high‐performance liquid chromatography respectively. Statistically significant differences were found between adapted and follow‐up infant formulas with respect to the available lysine and FUR contents. Available lysine contents decreased significantly throughout the storage time, and the contents at 37 °C were lower than at 20 °C. A statistically significant increase in FUR contents was observed during the storage period, with the contents being high at 37 °C than at 20 °C. A simple regression analysis between the available lysine and FUR contents during (a) the first year (b) the second year and (c) the two storage years was applied. The best correlations were obtained during the first year of storage. The results obtained show a clear MR evolution during the storage of infant formulas. Copyright © 2003 Society of Chemical Industry     

Normalization of cognitive and functional assessment instruments for dementia (NORMACODEM) (I): objectives, content and population]

We give an account of the first Austrian clinical results of a prospective study dealing with fractures of the femoral shaft treated with the UFN-system, the intraoperative handling especially considering the intra- and postoperative complications. The UFN-system combines the advantages of numerous proximal interlocking options for the treatment of nearly all femoral fracture patterns with that of the unreamed nailing (biological osteosynthesis, primary stability with individual after-treatment, high patient's comfort and early mobilisation). Within two years (VII/94-VII/96) sixty closed and four second degree open fractures were stabilized with the unreamed femoral nail. In twelve cases we used the spiral blade interlocking technique. Five times we changed from external fixator to the UFN. The fractures were classified according to the AO-classification. In 64 implanted UFN there occurred twelve intraoperative and four postoperative complications. In five cases reoperation was necessary. Failings in the operative technique, numerous different experienced surgeons and a deficient after_treatment led to our pitfalls.     

Conflict and Cooperation on International Rivers: The Case of the Colorado River on the US‐Mexico Border

This paper describes the work of the International Boundary and Water Commission, United States and Mexico (IBWC), to find cooperative solutions to issues pertaining to the Colorado River along the US-Mexico border. Since 1944, the IBWC has worked to resolve issues related to the distribution of the waters of the Colorado River between the United States and Mexico; salinity of waters delivered to Mexico; conveyance capacity of the Colorado River; and the conditions of the Colorado River Delta. The IBWC has emphasized binational cooperation to explore both short-term and long-term solutions to these issues.     

A study of the drainages of the pyrite mines of Aljustrel (Portugal)

Characterization of the pollution charge of drainages from pyrite mines of Aljustrel (Portugal) was made. Laboratory experiments were performed in order to recover copper by cementation and remove iron, zinc and acidity by neutralization with lime. It was found that the removal of the metal ions is completed when pH reaches a step at 5.0–5.5, whichever the ratio between Fe(II) and Fe(III).     

Nanostructured copper/porous silicon hybrid systems as efficient sound-emitting devices

In the present work, the photo-acoustic emission from nanostructured copper/porous silicon hybrid systems was studied. Copper nanoparticles were grown by photo-assisted electroless deposition on crystalline silicon and nanostructured porous silicon (nanoPS). Both the optical and photo-acoustic responses from these systems were determined. The experimental results show a remarkable increase in the photo-acoustic intensity when copper nanoparticles are incorporated to the porous structure. The results thus suggest that the Cu/nanoPS hybrid systems are suitable candidates for several applications in the field of thermoplasmonics, including the development of sound-emitting devices of great efficiency.     

Detection and Localization of Delaminations in Thin Carbon Fiber Reinforced Composites with the Ultrasonic Polar Scan

In this paper, the hybrid compliance-stiffness matrix method for simulating wave propagation in (delaminated) multilayered media with viscoelastic anisotropy has been confronted with high-quality amplitude and phase experiments on delaminated composites, obtained using the ultrasonic polar scan setup (UPS) in transmission by considering harmonic as well as pulsed ultrasound. Results are presented for multiple thin carbon/epoxy laminates with an artificial edge delamination induced by a foil insert, showing a good agreement between experimental recording and numerical modeling. The obtained results further reveal the feasibility of the harmonic UPS to detect and even locate the depth-position of multiple delaminations in fiber reinforced composites. Considering that the harmonic UPS method does not rely on the detection of different echoes like the classical C-scan, but rather expounds the conditions for efficient stimulation of guided waves in the solid, the method is found to be highly suited for inspecting thin composite materials for the presence of delaminations.