Sulfur–Iodine plant for large scale hydrogen production by nuclear power

The Sulfur–Iodine (S_I) cycle, driven by nuclear power, seems to be one of the main candidates to produce hydrogen on a large scale. A new S_I process flowsheet is proposed, set up at CEA and simulated by ProSim code and, based on that, data and results on the coupling of the thermochemical plant with a Very High Temperature Nuclear Reactor (VHTR) are presented. The scale up to industrial level, the conceptual design and cost estimation of the plant are then presented and discussed. In order to support a high temperature aggressive environment, well established chemical engineering methods as well as non traditional materials, devices and technologies have been selected. The influence of the adopted technology on the H₂ cost has also been investigated and is widely discussed, comparing two different cases. An economic sensitivity analysis carried out by varying the hydrogen production level is presented, showing that an optimum H₂ production exists and, due to relevant heat recovery processes, the minimum cost is not achieved for the maximum allowable H₂ production rate. Finally an optimized layout for the minimum cost plant, set up adopting the pinch technique, is presented leading to a further reduction of H₂ production costs.     

Measurement of magnetic fields radiated from ESD using fieldsensors

The goal of this paper is to show that commercial sensors, whose frequency response is not specifically designed, can be effectively used to measure very fast transient fields applying a proper reconstructing procedure based on the knowledge of the sensor transfer function. To do this, it is necessary to characterize a structure supporting a transverse electromagnetic (TEM) field, that will be used to set up a calibration procedure for elementary magnetic field sensors. The approach is completely analytical and allows us to know rigorously the field inside the structure. From the knowledge of this field, the transfer function of the sensor, in amplitude and phase, is evaluated up to 2 GHz. The complete characterization of the sensor allows us to reconstruct the sensed field from its output voltage waveform. The calibration procedure is carried out in time domain and therefore the fast Fourier transform (FFT) algorithm is used to achieve the sensor transfer function, as well as an inverse FFT (IFFT) is necessary to retrieve the transient impinging field. An experimental validation of the procedure shows the consistency of the approach     

Landsat TM image texture and moisture variations of the soil surface under the rainforest of the Rondonia state,Brazil

A Landsat TM image, part of a rainforest located in the state of Rondonia, Brazil, was analysed using Fourier transform techniques in order to extract textural features. The lattice-like texture pattern recorded was then compared with the geological structural trends of the area, and measures of the soil surface moisture treated by geostatistical analysis. The consistency between the different sets of analysis suggests that the spatial distribution of moisture at the soil surface is related to the structure of the bedrock. The near infrared channel of the Landsat TM may be used to record trends in water content distributions at the soil surface under homogeneous forest canopies.     

Capillary electrophoresis, nuclear magnetic resonance and mass spectrometry studies of opposite chiral recognition of chlorpheniramine enantiomers with various cyclodextrins

Markedly different chiral separation abilities were observed for native beta-cyclodextrin (beta-CD), carboxymethyl-beta-CD (CM-beta-CD) and heptakis (2,3,6-tri-O-methyl)-beta-CD (TM-beta-CD) towards the enantiomers of (+/-)-chlorpheniramine ((+/-)-CHL) in capillary electrophoresis (CE). Native beta-CD afforded almost baseline enantioseparation at a concentration of 18 mg/mL, whereas only 1 mg/mL solution of CM-beta-CD was required for adequate enantioseparation. TM-beta-CD allowed the nearly baseline enantioseparation only at a concentration as high as 80 mg/mL. Moreover, the migration order of (+/-)-CHL in the presence of TM-beta-CD was opposite to that with beta-CD and CM-beta-CD. 1H and 13C-NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS) have been used in order to obtain preliminary information about the stoichiometry and the binding constants in the intermolecular diastereomeric complexes of (+/-)-CHL with these CDs.     

Impact of inherited polymorphisms in glutathione S-transferase M1, microsomal epoxide hydrolase, cytochrome P450 enzymes on DNA, and blood protein adducts of benzo(a)pyrene-diolepoxide

The benzo(a)pyrene (BaP) metabolite benzo(a)pyrenediolepoxide (BPDE) is strongly implicated as a causative agent of lung cancer. To assess the risk of exposure to BaP, we made a combined analysis of levels of BPDE adducts to hemoglobin (Hb), serum albumin (SA), and lymphocyte DNA in 44 patients with incident lung cancer, as a prototype of a population mainly exposed to tobacco-derived BaP. We also investigated whether genetic polymorphisms of cytochrome P450IA1 (CYPIA1), microsomal epoxide hydrolase (mEH), and glutathione S-transferase M1 (GSTM1), which are involved in BaP metabolism, can be determinants of adduct formation. BPDE-Hb, BPDE-SA, and BPDE-DNA adducts were quantified as BaP tetrols released from hydrolysis of macromolecules and measured by high-resolution gas chromatography-negative ion chemical ionization-mass spectrometry to achieve high specificity and sensitivity. Individuals with detectable Hb adducts were positive for SA adducts but not vice versa, suggesting that BPDE-Hb adducts are less informative indicators of BaP exposure. Using PCR methods on DNA, we characterized GSTM1 deletion, CYPIA1 MspI and exon 7 valine variants, and mEH polymorphisms at amino acid positions 113 (EH3) and 139 (EH4). Levels of BPDE adducts were no different among CYPIA1, mEH, and GSTM1 genotypes. However, individuals with measurable BPDE-SA adducts were CYPIA1 variant carriers more frequently (P = 0.03). There was a slightly higher percentage of DNA detectable adducts in subjects with CYPIA1 exon 7 valine polymorphism. When subjects were classified by both polymorphisms on the mEH gene, those with two slow alleles (EH3 homozygous mutated) and no fast alleles (EH4 homozygous wild type) had a lower frequency of BPDE-SA adducts and no DNA adducts (P = 0.06). These results are based on a small number of observations thus far, but this exploratory study suggests that CYPIA1 and mEH variants might have an impact on BPDE exposure markers such as BPDE-SA adducts. Chemical specificity in adduct measurements is important to identify the biomarkers that reflect BaP exposure more accurately.     

A rigorous model for radiated emission prediction in PCB circuits

The problem of the radiated emission from printed circuit boards, (PCBs) is theoretically and experimentally investigated. Differential mode and common mode currents are separately studied by means of a rigorous method based on proper Green's functions. The solution of the integral equations for the current distribution, derived from the problem formulation, is numerically achieved by the method of moments. Simulated results are in good agreement with measurements. The final products of this study are masks that establish the maximum allowable currents or voltage values as a function of frequency to comply with CISPR regulation     

Effect of heat treatments on mechanical properties and fracture behavior of a thixocast A356 aluminum alloy

The effect of different heat treatments (T5 and T6) on mechanical properties, fracture behavior and damage evolution of A356 Thixocast aluminum alloy have been examined in detail in the present work. Tensile tests of the material have been performed in the as cast and as treated conditions in order to observe the different fracture behavior in consequence of the heat treatments. Optical and scanning electron microscopy techniques have been used to characterize the microstructure and fracture surfaces of the specimens. Finally, the precipitation processes of the material have been analyzed by hardness and electrical conductivity measurements and EDS analysis has been used to characterize the different phases in the as-thixo and as-treated conditions.     

Lymphangiosarcoma of the pubic region: a rare complication arising in congenital non-hereditary lymphedema

Lymphangiosarcoma is a rare, aggressive, vascular neoplasm arising in chronic congenital or acquired lymphedema. Although it is most frequently associated with post-mastectomy lymphedema (Stewart-Treves's syndrome), lymphangiosarcoma can exceptionally arise in congenital hereditary lymphedema (Milroy's syndrome and Meige's syndrome) and non-hereditary lymphedema (congenital, praecox or forme tarde lymphedemas). We report a case of lymphangiosarcoma of the pubic region, supported by immunohistochemical studies, in a 42-year-old woman affected by congenital, non-hereditary lymphedema of the left genital region and homolateral lower limb. In addition, molecular analysis demonstrated the absence of Kaposi's sarcoma-associated Herpes virus (KSHV) DNA sequences in tumour lesions. To our knowledge, this is the first case of lymphangiosarcoma associated with congenital non-hereditary lymphedema confined to the pubic region. The literature concerning the cases of lymphangiosarcoma arising in congenital hereditary and non-hereditary lymphedema is reviewed. Moreover, we emphasized the importance of regular clinical controls in all patients affected by chronic lymphedema. In fact, although the prognosis of this neoplasm is very poor, a prompt diagnosis and a rapid, ablative surgery associated with radiation therapy can increase the possibility of survival of these patients.