X-Ray Digital Radiography to Study Gold–Silver Nose Decorations from the Moche Tomb of the Lady of Cao

In the present study nose decorations from the tomb of the ‘Lady of Cao’, a mummified Moche woman dated around third–fourth century AD, were analyzed by a portable X-ray digital radiography (XDR) system. The Moche civilization flourished along the north coast of present-day Peru, between the Andes and the Pacific Ocean, approximately between 100 and 600 AD. The Moche were very sophisticated artisans and metal smiths, so that they are considered the finest producers of jewels and artifacts of the region. Their metalworking ability was impressively demonstrated by the excavations of the tomb of the ‘Lady of Cao’, discovered by Regulo Franco in 2005. More than 100 beautiful jewels were found in this tomb, among them about 40 nose decorations composed of a combination of gold and silver sheets. Radiographs of several of them were carried out, with the aim to evaluate the gold–silver joining process, to check the homogeneity of the alloy and to quantify the thickness of the sheets. The XDR system consisted of a mini X-ray tube and of a digital X-ray flat panel. The radiographic images of the nose decorations revealed details of the manufacturing process and of the Au–Ag junction.     

Agglomerate behavior in a recirculating fluidized bed with sheds: Effect of sheds

A Radioactive Particle Tracking (RPT) technique was used to study the effects of the internal baffles in the stripping section of the Fluid Coker?, called sheds, have on the behavior of wet agglomerates that are formed when residual oil is injected into the Coker. Vapor emitted by reacting wet agglomerates below the sheds rises and causes shed fouling. The release of vapor from agglomerates can be estimated by combining the RPT results with a coking reaction model. The study found that the sheds reduce the time agglomerates spend in the shed zone, which in turn reduces the amount of organic vapor that reaches the sheds, but at the same time increase the wetness of the agglomerates that exit to the recirculation line, which results in the loss of valuable liquid. The research also found that the best type of shed, from the point of view of agglomerate motion, is the mesh-shed. Finally, experimental data indicate that reducing the cross sectional area of the sheds from 50% to 30% increases the time that the agglomerates spend above the shed zone, and thus reduces the flow of vapor emitted below the sheds.     

A new route to graphene starting from heavily ozonized fullerenes: Part 2—oxidation in air

Graphite oxide (GO) and heavily ozonized C₆₀ and C₇₀ fullerenes known as “fullerene ozopolymers” were studied by TGA-FTIR (Thermogravimetry coupled with FT-IR spectroscopy), DTG (Differential Thermogravimetry) and DTA (Differential Thermal Analysis) in air flow. It was found that GO burns at 70°C higher temperature than the fullerene ozopolymers. This different behavior toward the thermal oxidation of GO is due to the size of the oxidized and staked graphene layers which are expected to be significantly larger than those of the fullerene ozopolymers. Furthermore, the latter should necessarily have a buckybowl shaped structure which should favor their reactivity with oxygen.     

FPGA Implementation of Neurocomputational Models: Comparison Between Standard Back-Propagation and C-Mantec Constructive Algorithm

Recent advances in FPGA technology have permitted the implementation of neurocomputational models, making them an interesting alternative to standard PCs in order to speed up the computations involved taking advantage of the intrinsic FPGA parallelism. In this work, we analyse and compare the FPGA implementation of two neural network learning algorithms: the standard and well known Back-Propagation algorithm and C-Mantec, a constructive neural network algorithm that generates compact one hidden layer architectures with good predictive capabilities. One of the main differences between both algorithms is the fact that while Back-Propagation needs a predefined architecture, C-Mantec constructs its network while learning the input patterns. Several aspects of the FPGA implementation of both algorithms are analyzed, focusing in features like logic and memory resources needed, transfer function implementation, computation time, etc. The advantages and disadvantages of both methods in relationship to their hardware implementations are discussed.     

A novel technique for residence time distribution (RTD) measurements in solids unit operations

This work presents a novel technique with fast response for Residence Time Distribution (RTD) measurements in gas-solid unit operations (e.g., fluidized bed reactors). This technique is based on an optical method which eliminates the requirement of knowing the velocity and concentration profiles at the exit section of the system. Experiments were carried out with SiC particles and a phosphorescent pigment used as a tracer. A concentration measurement system was developed to measure the tracer concentration in SiC/pigment mixtures. The corresponding pigment concentrations were evaluated at the bottom of this system using a photomultiplier. The pigment concentration was derived from the integral of the signal intensity received by the photomultiplier. Then, a calibration curve was established which provided the empirical relationship between the integral and pigment concentration. In order to validate this RTD measurement technique, a series of experiments was performed in a bubbling fluidized bed and the effect of the bed height was studied. It was shown that the experimental RTD curves were in good agreement with the theoretical RTD of bubbling fluidized beds. This solids RTD measurement technique can be used to provide a better understanding of the hydrodynamics of complex solids unit operations.     

Discrimination discovery in scientific project evaluation: A case study

Discovering contexts of unfair decisions in a dataset of historical decision records is a non-trivial problem. It requires the design of ad hoc methods and techniques of analysis, which have to comply with existing laws and with legal argumentations. While some data mining techniques have been adapted to the purpose, the state-of-the-art of research still needs both methodological refinements, the consolidation of a Knowledge Discovery in Databases (KDD) process, and, most of all, experimentation with real data. This paper contributes by presenting a case study on gender discrimination in a dataset of scientific research proposals, and by distilling from the case study a general discrimination discovery process. Gender bias in scientific research is a challenging problem, that has been tackled in the social sciences literature by means of statistical regression. However, this approach is limited to test an hypothesis of discrimination over the whole dataset under analysis. Our methodology couples data mining, for unveiling previously unknown contexts of possible discrimination, with statistical regression, for testing the significance of such contexts, thus obtaining the best of the two worlds.     

Heat-shock protein-27, -70 and peroxiredoxin-II show molecular chaperone function in sickle red cells: Evidence from transgenic sickle cell mouse model

Sickle cell disease (SCD) is an autosomal recessive genetic red cell disorder characterized by the production of a defective form of hemoglobin, hemoglobin-S, that is worldwide-distributed. The acute clinical manifestations of SCD are related to hemoglobin cyclic-polymerization and to the generation of rigid, dense red blood cells (RBCs). We studied RBCs membrane proteome from human sickle RBCs, fractioned according to density compared to normal RBCs. 2-DE followed by MS analysis was carried out. We identified 65 proteins differently expressed, divided into five major clusters according to their functions: (i) membrane-cytoskeleton proteins; (ii) metabolic enzymes; (iii) ubiquitin-proteasome-system; (iv) flotillins; (v) chaperones. HSP27, HSP70 and peroxiredoxin-II (Prx-II) showed the most relevant changes. They were differently recruited to sickle RBCs membrane in response to in vitro hypoxia. Potential markers were then validated in a transgenic-mouse model for SCD, the SAD mice, exposed to hypoxia mimicking acute SCD vaso-occlusive-crisis (VOCs); we found that HSP70 and HSP27 bound to RBCs membrane respectively after 12?h and 48?h of hypoxia, while Prx-II membrane binding was modulated during hypoxia. Our data indicate that HSP27 and HSP70 play a novel role as RBCs membrane protein protectors and as possibly new markers of severity of RBCs membrane damage during acute VOCs.     

The production of synthetic organic liquids from wood using a modified nickel catalyst

Extended batch reactions show that fast-growing hybrid poplar suspended in water is completely converted to oil and some gas when stirred at 340°C in the presence of Raney nickel. The oil is less viscous when hydrogen is present at sufficiently high pressure. The catalyst is stable up to the maximum time studied (14 hours). The oils typically contain 77% carbon, 7.5-8.5% hydrogen, and 12-13% oxygen, have viscosities in the range 5000-8000 mPa.s and higher heating values of around 35 MJ.kg^?1. Nickel produced by reduction of nickel carbonate in situ is also an effective and more practical catalyst.