Treatment of TENORM waste: Phosphogypsum produced in fertilizer industry

This study concerns treatment of phosphogypsum (PG) waste from phosphoric acid production, containing ²²⁶Ra as major radioactive contaminant. Physical and chemical treatment was performed. The physical treatment was based on the particle size separation (dry and wet frationation), whereas the chemical treatment was carried out using leaching solutions (single and sequential leaching processes). The results showed that the particle size separation affected the distribution of radionuclides in PG waste. High enrichment fators (Q) of ²²⁶Ra and ²¹⁰Pb were obtained in the wet fractionation. The Q value for ²²⁶Ra and ²¹⁰Pb was 3.1 and 3.9 compared to the PG bulk. The chemical leaching conditions of PG waste were optimized. In the single chemical leaching, 40% of total radium-226 in PG was removed. In the sequential leaching, about 87% of ²²⁶Ra was removed when the PG waste was washed with alkali solutions and pretreated and leached with a nitric acid solution.     

Preparation of polyHIPE/clay composites by using a reactive intercalant

Porous polymer composites have been synthesized by polymerizing the continuous phase of styrene/divinylbenzene high internal phase emulsions in the presence of organophilic montmorillonite clay having a novel oil‐based intercalant which is a reactive methacryl derivative of quaternized methyl oleate. The morphological features, thermal stability and mechanical properties, namely compression modulus and crush strength of the resulting composites have been investigated as a function of degree of nanoclay loading. All the composites reinforced with the clay were found to have improved thermal and mechanical properties as well as desired porous and interconnected structural morphology, as compared with the bare polyHIPE matrix. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41333.     

Parametric investigation of a double-effect solar still in comparison with a single-effect solar still

This paper reports the use of two mathematical models to compare the productivity of single-effect and double-effect solar stills under different climatic, design and operational parameters in Oman. The shallow water basin, 23° cover tilt angle, 0.1 m insulation thickness, and asphalt coating of the solar still were found to be the optimum design parameters that produced an average annual solar still yield of 4.15 kg/m²/d and 6 kg/m²/d for single and double effect solar stills, respectively. A cost analysis is carried out to shed some light on the potential of utilizing an array of single-effect solar stills or double-effect solar stills for the production of drinking water in remote areas in Oman. It has been found that the unit cost for distilled water using an array of single-effect solar stills is $74/1000 gal (16.3 $/m³) or $62.4/1000 gal (13.7 $/m³) when using a double-effect solar still. The cost saving is 15.7%.     

Platelet serotonin transporter in depressed children and adolescents: 3H-paroxetine platelet binding before and after sertraline

OBJECTIVE: To evaluate serotonin transporter protein (5HTPR) binding in platelets from children and adolescents with major depression (MDD) compared to normal controls using the selective ligand 3H-paroxetine. METHOD: Children and adolescents with MDD (n = 24) defined by DSM-III-R criteria and normal controls (n = 22) were compared by platelet 5HTPR kinetic analysis with the hypothesis that 5HTPR is reduced in MDD. A subset of MDD subjects (n = 18) continued to participate in a fixed-dose, open-label sertraline trial for 6 weeks followed by drug-free washout and repeated 5HTPR analysis. RESULTS: Sex, prepubertal status, and age had no effect on 5HTPR. Medication-free MDD subjects differed from controls in reduced binding capacity (Bmax) (p < .001). Sertraline therapy decreased binding affinity from baseline non-selectively (p < .05), and Bmax elevation from baseline was associated with nonresponse and suicide attempt history. CONCLUSION: Earlier literature in this population is replicated with regard to reduced platelet 5HTPR Bmax in MDD. Findings support a continuum of 5HTPR involvement in MDD across the developmental spectrum.     

Mesenchymal chondrosarcoma of the orbit. Report of three new cases and review of the literature

BACKGROUND: Extraskeletal mesenchymal chondrosarcoma is a rare tumor characterized by undifferentiated mesenchymal cells with islands of mature hyaline cartilage. Considering all sites, long-term survival is approximately 30%. Only seven cases of orbital mesenchymal chondrosarcoma have been reported. METHODS: The records of three cases of orbital mesenchymal chondrosarcoma treated at the Columbia-Presbyterian Medical Center, and the seven previously reported cases of this tumor were reviewed to determine clinical characteristics and appropriate therapy. RESULTS: Nine of the 10 patients were female; age of onset ranged from 10 to 35 years. Of eight patients with at least 2 years of observation, five survived 5 or more years after resection, or after resection plus adjuvant therapy. Two patients died of metastatic disease 2 and 5 years, respectively, after the initial treatment, and one died of pneumonia 6 months after surgery. Review of the histology of the three cases treated at Columbia-Presbyterian Medical Center did not identify distinct histologic types that might guide therapy. Presenting symptoms were typical of symptoms of an orbital mass: proptosis, pain, diplopia, change in visual acuity, ptosis, and tearing. CONCLUSION: The small number of reported cases of mesenchymal chondrosarcoma of the orbit prevents definitive conclusions, but it appears that resection is adequate therapy in some cases. Extraskeletal mesenchymal chondrosarcoma of the orbit may have a better prognosis than tumors in other sites.     

Computed tomography as a guide in the diagnosis and follow-up of brain abscesses

The diagnosis and follow-up of 20 cases of intracranial abscess are analyzed, with particular attention to the role of computed tomography (CT). the differential diagnosis of the CT appearance is presented, and the value of clinical and laboratory findings is discussed. Of special interest is the potential effect of steroids on CT findings as well as the frequent observation of a residual enhancing focus seen on the scan obtained at hospital discharge.     

A new bath for the electrodeposition of aluminium. I. conductivity measurements

The conductivity of mixed hydrides of aluminium chloride and lithium-aluminium hydride in a mixed solvent of tetrahydrofuran (THF) and toluene was measured with respect to the total concentration of aluminium and also to the molar ratio of LiAlH₄ to AlCl₃. The values obtained were compared with those of the THF-benzene mixed solvent and those of the NBS (National Bureau of Standards) bath –AlCl₃ and LiAlH₄ in dithyl ether. The results showed that a solution of AlCl₃ and LiAlH₄ with a molar ratio of 3:1, respectively, in THF-toluene (80 vol% toluene) with a total concentration of aluminium of about 1.0 moll^–1, has a suitable conductivity for the electrodeposition and dissolution of aluminium. In addition to its low price, the electrolytic bath obtained has low volatility and relatively good stability with respect to the other baths studied.