Behavior of Ni20Cr Alloy in Molten Nitrate Salts

This study reports the behavior of the Ni20Cr alloy in molten nitrate salts. Its behavior was evaluated in the eutectic mixture called Solar Salt (binary salt) and in a ternary mixture (90% Solar Salt and 10% lanthanum nitrate). The addition of lanthanum nitrate was performed to determine if the presence of the La³⁺ cation could act as a corrosion inhibitor. Through mass loss and potentiodynamic polarization studies, the effects of both electrolytes on the corrosion resistance of the alloy at 300, 400, and 500 °C and at exposure times of 250, 500, 750, and 1000 h were determined. The results showed an increase in the corrosivity of the ternary salt, due to a decrease in its melting point and an increase in the concentration of nitrate ions. However, it was observed that the La³⁺ cations formed a protective layer (La₂O₃) on the alloy surface. In both corrosive media, the Ni20Cr alloy showed excellent corrosion resistance, due to its ability to form protective layers of Cr₂O₃, NiO, and NiCr₂O₄, in addition to the presence of a layer of La₂O₃ in the case of the ternary salt.     

Aggregated Genomic Data as Cohort-Specific Allelic Frequencies can Boost Variants and Genes Prioritization in Non-Solved Cases of Inherited Retinal Dystrophies

The introduction of NGS in genetic diagnosis has increased the repertoire of variants and genes involved and the amount of genomic information produced. We built an allelic-frequency (AF) database for a heterogeneous cohort of genetic diseases to explore the aggregated genomic information and boost diagnosis in inherited retinal dystrophies (IRD). We retrospectively selected 5683 index-cases with clinical exome sequencing tests available, 1766 with IRD and the rest with diverse genetic diseases. We calculated a subcohort’s IRD-specific AF and compared it with suitable pseudocontrols. For non-solved IRD cases, we prioritized variants with a significant increment of frequencies, with eight variants that may help to explain the phenotype, and 10/11 of uncertain significance that were reclassified as probably pathogenic according to ACMG. Moreover, we developed a method to highlight genes with more frequent pathogenic variants in IRD cases than in pseudocontrols weighted by the increment of benign variants in the same comparison. We identified 18 genes for further studies that provided new insights in five cases. This resource can also help one to calculate the carrier frequency in IRD genes. A cohort-specific AF database assists with variants and genes prioritization and operates as an engine that provides a new hypothesis in non-solved cases, augmenting the diagnosis rate.     

Distributed text search using suffix arrays

Text search is a classical problem in Computer Science, with many data-intensive applications. For this problem, suffix arrays are among the most widely known and used data structures, enabling fast searches for phrases, terms, substrings and regular expressions in large texts. Potential application domains for these operations include large-scale search services, such as Web search engines, where it is necessary to efficiently process intensive-traffic streams of on-line queries. This paper proposes strategies to enable such services by means of suffix arrays. We introduce techniques for deploying suffix arrays on clusters of distributed-memory processors and then study the processing of multiple queries on the distributed data structure. Even though the cost of individual search operations in sequential (non-distributed) suffix arrays is low in practice, the problem of processing multiple queries on distributed-memory systems, so that hardware resources are used efficiently, is relevant to services aimed at achieving high query throughput at low operational costs. Our theoretical and experimental performance studies show that our proposals are suitable solutions for building efficient and scalable on-line search services based on suffix arrays.     

Effects of γ radiation on fiber‐reinforced polymer concrete

Composites were made from 30% unsaturated polyester resin + 70% calcium bentonite and marble as aggregates, as well as 0.3 and 0.4 vol% of nylon fibers. The fiber‐containing polymer concretes (PCs) were subjected to 5, 10, 50, and 100 kGy applied radiation doses. The compressive strength values depend on both the fiber concentration and the irradiation dose applied. Moreover, the polyester‐based PCs containing two mineral aggregates, calcium carbonate and marble, have lower compressive strength values than those reported earlier for PCs containing only either silica sand or CaCO₃. However, significant improvement of the compressive strain and the compression modulus of elasticity are achieved when nylon fibers are added. Both these properties go symbatically with the radiation dose. Mechanical characteristics can be related to the morphological features observed by scanning electron microscopy. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

Platinum and Palladium Organometallic Compounds: Disrupting the Ergosterol Pathway in Trypanosoma cruzi

Current treatment for Chagas’ disease is based on two drugs, Nifurtimox and Benznidazol, which have limitations that reduce the effectiveness and continuity of treatment. Thus, there is an urgent need to develop new, safe and effective drugs. In previous work, two new metal-based compounds with trypanocidal activity, Pd-dppf-mpo and Pt-dppf-mpo, were fully characterized. To unravel the mechanism of action of these two analogous metal-based drugs, high-throughput omics studies were performed. A multimodal mechanism of action was postulated with several candidates as molecular targets. In this work, we validated the ergosterol biosynthesis pathway as a target for these compounds through the determination of sterol levels by HPLC in treated parasites. To understand the molecular level at which these compounds participate, two enzymes that met eligibility criteria at different levels were selected for further studies: phosphomevalonate kinase (PMK) and lanosterol 14-α demethylase (CYP51). Molecular docking processes were carried out to search for potential sites of interaction for both enzymes. To validate these candidates, a gain-of-function strategy was used through the generation of overexpressing PMK and CYP51 parasites. Results here presented confirm that the mechanism of action of Pd-dppf-mpo and Pt-dppf-mpo compounds involves the inhibition of both enzymes.     

Algebraic surrogate-based process optimization using Bayesian symbolic learning

Here, we propose a strategy for the global optimization of process flowsheets, a fundamental problem in process systems engineering, based on algebraic surrogates that are built from rigorous simulations via Bayesian symbolic regression. The applied method provides a closed-form expression that can be optimized to global optimality using state-of-the-art solvers, where BARON or ANTIGONE were the solvers of choice. When predicting unseen test data, the algebraic models show a similar accuracy level compared to traditional surrogates based on Gaussian processes. However, they can be more easily optimized to global optimality due to their analytical closed-form structure, which allows the user to apply well-established global deterministic solvers. We show the capabilities of our approach in several case studies, ranging from process units to full flowsheets. The performance of our approach is assessed by comparing the CPU time for model building, the prediction accuracy of the identified model, and the CPU time for the subsequent optimization with a proven benchmark.     

The crystallization of polypropylene in multiwall carbon nanotube‐based composites

The crystallization process of isotactic polypropylene (iPP) was studied under both dynamic and isothermal conditions for a series of multiwall carbon nanotube (MWCNT) composites with nanotube concentrations between 0.1 and 1.0% by weight. The nucleation activity of the nanofillers was confirmed for both dynamic and isothermal crystallization, and was shown to be composition dependent. The effect of the nanofiller on the crystallization of iPP was discussed using the temperature coefficients obtained to determine the interfacial free energy and free energy of nucleation. The basal interfacial free energy decreased with respect to that of neat iPP by up to 15% for as little as 0.1% MWCNT, subsequently decreasing linearly with increasing nanotube concentration. This behavior is in line with the crystallization behavior of iPP with conventional nucleating agents. POLYM. COMPOS., 2011. © 2010 Society of Plastics Engineers     

In‐Situ Growth of Ultrathin Films of NiFe‐LDHs: Towards a Hierarchical Synthesis of Bamboo‐Like Carbon Nanotubes

The synthesis of ultrathin films (UTFs) of NiFe‐LDHs has been achieved by means of an in situ hydrothermal approach, leading to a flat disposition of the LDH crystallites on the substrate, in clear contrast to the most common perpendicular orientation reported to date. Experimental factors like time of synthesis or the nature of the substrate, seem to play a crucial role during the growing process. The 2D morphology of the NiFe‐LDH crystallites was kept after a calcination procedure, leading to a topotactic transformation into mixed‐metal oxide platelets. Hereby, in order to study the catalytic behavior of our samples, a chemical vapor deposition process is explored upon the as‐synthesized films. In presence of a carbon source (ethylene), these films catalyze a preferential low‐temperature (550 °C) growth of bamboo‐like carbon nanotubes, in stark contrast to the different mixture of carbon nanoforms obtained from the bulk samples. This work opens the door for the development of UTFs based on LDHs, which may be of utmost importance in a wide range of potential applications ranging from magnetic storage, catalysis or biomedical applications, to electrochemical batteries, anti‐corrosion and superhydrophobic coatings.     

Distributed manufacturing for electrified chemical processes in a microgrid

To alleviate the greenhouse gas emissions by the chemical industry, electrification has been proposed as a solution where electricity from renewable sources is used to power processes. The adoption of renewable energy is complicated by its spatial and temporal variations. To address this challenge, we investigate the potential of distributed manufacturing for electrified chemical processes installed in a microgrid. We propose a multiscale mixed-integer linear programming model for locating modular electrified plants, renewable-based generating units, and power lines in a microgrid that includes monthly transportation and hourly scheduling decisions. We propose a K-means clustering-based aggregation disaggregation matheuristic to solve the model efficiently. The model and algorithm are tested using a case study with 20 candidate locations in Western Texas. Additionally, we define a new concept, “the Value of the Multi-scale Model,” to demonstrate the additional economic benefits of our model compared with a single-scale model.