Hydrometallurgical route to recover molybdenum, nickel, cobalt and aluminum from spent hydrotreating catalysts in sulphuric acid medium

This work describes a hydrometallurgical route for processing spent commercial catalysts (CoMo and NiMo/Al₂O₃), for recovering the active phase and support components. They were initially pre-oxidized (500 °C, 5 h) in order to eliminate coke and other volatile species present. Pre-oxidized catalysts were dissolved in H₂SO₄ (9 mol L⁻¹) at 90 °C, and the remaining residues separated from the solution. Molybdenum was recovered by solvent extraction using tertiary amines. Alamine 304 presented the best performance at pH around 1.8. After this step, cobalt (or nickel) was separated by adding aqueous ammonium oxalate in the above pH. Before aluminum recovery, by adding NaOH to the acid solution, phosphorus (H₂PO₄⁻) was removed by passing the liquid through a strong anion exchange column. Final wastes occur as neutral and colorless sodium sulphate solutions and the insoluble solid in the acid leachant. The hydrometallurgical route presented in this work generates less final aqueous wastes, as it is not necessary to use alkaline medium during the metal recovery steps. The metals were isolated in very high yields (>98 wt.%).     

Overvaluation of shape and weight in binge eating disorder and overweight controls: Refinement of a diagnostic construct.

Debate continues regarding the nosological status of binge eating disorder (BED) as a diagnosis as opposed to simply reflecting a useful marker for psychopathology. Contention also exists regarding the specific criteria for the BED diagnosis, including whether, like anorexia nervosa and bulimia nervosa, it should be characterized by overvaluation of shape/weight. The authors compared features of eating disorders, psychological distress, and weight among overweight BED participants who overvalue their shape/weight (n = 92), BED participants with subclinical levels of overvaluation (n = 73), and participants in an overweight comparison group without BED (n = 45). BED participants categorized with clinical overvaluation reported greater eating-related psychopathology and depression levels than those with subclinical overvaluation. Both BED groups reported greater overall eating pathology and depression levels than the overweight comparison group. Group differences existed despite similar levels of overweight across the 3 groups, as well as when controlling for group differences in depression levels. These findings provide further support for the research diagnostic construct and make a case for the importance of shape/weight overvaluation as a diagnostic specifier. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

有待开发和引导的成人失禁用品市场

成人失禁用品和婴儿纸尿裤就像是葡萄酒和红酒,尽管它们起源相同,但实际上却是两种截然不同的东西。婴儿纸尿裤的目标很简单,就是为了满足婴儿父母的需求。一是确保纸尿裤不漏尿,二是让婴儿纸尿裤穿着时保持干爽舒适。成人失禁用品却没有这么简单。     

Volumetric texture segmentation by discriminant feature selection and multiresolution classification

In this paper, a multiresolution volumetric texture segmentation (M-VTS) algorithm is presented. The method extracts textural measurements from the Fourier domain of the data via subband filtering using an orientation pyramid (Wilson and Spann, 1988). A novel Bhattacharyya space, based on the Bhattacharyya distance, is proposed for selecting the most discriminant measurements and producing a compact feature space. An oct tree is built of the multivariate features space and a chosen level at a lower spatial resolution is first classified. The classified voxel labels are then projected to lower levels of the tree where a boundary refinement procedure is performed with a three-dimensional (3-D) equivalent of butterfly filters. The algorithm was tested with 3-D artificial data and three magnetic resonance imaging sets of human knees with encouraging results. The regions segmented from the knees correspond to anatomical structures that can be used as a starting point for other measurements such as cartilage extraction.     

Numerical and experimental analysis of microstructure formation during stainless steels solidification

The aim of this work is to examine microstructure formation during the solidification of unidirectional solidified AISI 304 stainless steel. Numerical and experimental results indicate that this numerical model allows a precise analysis of the AISI 304 stainless steel microstructure formation. This model determines temperature profiles, position of liquid and solid isotherms, thermal parameters (thermal gradients, tip rate movement, rate cooling), and finally, the secondary inter dendritic spacing. This model was tested by comparing the experimental values results, and thus a reasonable correlation was found.     

Reversible toluene adsorption on monolithic carbon aerogels

Thirteen monolithic carbon aerogels with different pore textures were used as toluene adsorbents. Adsorption was carried out under both static and dynamic conditions. Under static conditions at 25 degrees C and at saturation, an adsorption capacity as high as 1.36 cm(3) g(-1) or 1180 mg g(-1) was obtained. Toluene adsorption was a reversible process in all carbon aerogels, and the adsorbed toluene was completely recovered by heating them at 400 degrees C. Regenerated adsorbents showed larger surface area and micropore width than the original samples, indicating that no pore blockage was produced. Adsorption under dynamic conditions at 100 degrees C was also completely reversible after at least three consecutive adsorption-desorption cycles. The ability of these carbon aerogels to reversibly adsorb toluene could be useful for their application in thermal swing adsorption or pressure swing adsorption equipment.     

Indirect electrochemical oxidation of cyanide by hydrogen peroxide generated at a carbon cathode

The oxidation of cyanide was performed in aqueous sodium hydroxide solutions. Cyanide was oxidized over 90% to cyanate by hydrogen peroxide electrochemically generated at a 60 ppi reticulated vitreous carbon electrode from oxygen reduction. Cyanide depletion was recorded as a function of time from the analysis of cyanide based on the titration procedure using silver nitrate with p$p$-dimethylamino-benzal-rhodanine indicator. Cyanate was further oxidized to mineralization by decreasing the pH of the solution obtaining a recovery of carbon dioxide over 90%. The employment of copper together with hydrogen peroxide to increase the destruction of cyanide was also studied. Different molar ratios of hydrogen peroxide/cyanide and copper/cyanide were tested achieving over 98% of cyanide destruction in a time period of 40 min by increasing either the concentration of hydrogen peroxide or copper ion.