A pretest for using logrank or Wilcoxon in the two-sample problem

In a two-sample location-scale model with censored data, the logrank test is asymptotically efficient when the error distribution is extreme minimum value. On the other hand, the Wilcoxon test is asymptotically efficient when the error distribution is logistic. We propose a pretest for choosing between logrank and Wilcoxon by determining if the error distribution is closer to extreme minimum value or logistic. This adaptive test is compared with the logrank and Wilcoxon tests through simulation.     

Influence of distillation parameters on the extraction of Juniperus communis L. in vapour infused gin

The influence of distillation parameters on the extraction of flavour compounds from the gin botanical Juniperus communis L. using vapour infusion was investigated. The optimum mix of conditions to extract the highest levels of certain compounds was established using a 3³-factorial design. Quantification using solid-phase microextraction and gas chromatography coupled mass spectrometry, was performed measuring nine common flavour compounds. The greatest influence was the botanical ratio, whilst the least influential parameter was ethanol concentration for all compounds except terpinen-4-ol. Density functional theory calculations of quantitative structure–activity relationship properties for the flavour compounds were also undertaken to test for molecular influence on solvent extraction. The quantitative structure–activity relationship model showed the highest dipole moment for terpinen-4-ol and the lowest for γ-terpinene. © 2020 The Institute of Brewing & Distilling     

An optical packet metro architecture for Fixed Mobile Convergence in the cloud era

Photonic Network Communications - The present paper addresses future network architectures considered for Fixed Mobile Convergence, where users can access resources transparently either through...     

Occurrence of aflatoxin B1, citrinin and ochratoxin A in rice in five provinces of the central region of Vietnam

The possible coexistence of three mycotoxins in rice, including aflatoxin B1 (AFB1), citrinin (CIT) and ochratoxin A (OTA), was investigated. The samples of rice were collected in large markets in five provinces of the central region of Vietnam. These toxins were extracted, purified and finally quantified by HPLC with fluorimetry detection. Contamination of AFB1 was found to be the most, followed by OTA, while contamination of CIT was insignificant. The coexistence of CIT with AFB1/OTA in rice was found in high percentage. Some samples overpassed the authorized limit by Europe in OTA and/or AFB1.     

Emergence of genomic self-similarity in location independent representations

A key property for predicting the effectiveness of stochastic search techniques, including evolutionary algorithms, is the existence of a positive correlation between the form and the quality of candidate solutions. In this paper we show that when the ordering of genomic symbols in a genetic algorithm is completely independent of the fitness function and therefore free to evolve along with the candidate solutions it encodes, the resulting genomes self-organize into self-similar structures that favor this key stochastic search property.     

Silk Hydrogel Microfibers for Biomimetic Fibrous Material Design

Fiber units are conserved design motifs that bestow intrinsic stiffness to biological tissues. Collagen fibrils are the fundamental unit of fibrous tissues with controlled assembly and multiscale structure‐function properties. Characteristic non‐linear tissue response is afforded through energy dissipation at the stiff‐soft interfaces of fibril collagen and extrafibrillar matrix components. The goal of this research is to develop a 3D silk hydrogel microfiber platform with bioinspired toughening mechanisms. Batch fabrication and post‐processing renders fibers that can be handled and with tunable features, as well as loading of components to improve material responses. Matrix loading of a glycoprotein, bovine serum albumin (BSA), adds a primary defense mechanism to material failure in the form of sacrificial bonds. This enables nano‐ to micro‐scale rearrangement with strain and improved fiber toughness compared to silk‐only fibers. Further biomimicry is added via matrix loading of a biosilica precursor peptide, R5, enabling biomineralization in the form of silicification. Inorganic mineral deposition of Silk‐BSA‐R5 hydrogel microfibers provides a fibrous scaffold for applications that require fibril‐mineral interfaces for load transduction. This microfiber platform introduces a methodology for meticulous fibrous scaffold design with biomimetic fibril hierarchy, toughening mechanisms, and loading capabilities for systematic tissue engineering applications.     

Real time TEM observation of alumina ceramic nano-particles during compression

The behavior of alumina nano-particles taken from a commercial powder is investigated during in situ compression experiments in a transmission electron microscope (TEM). Small particles of 40 nm in diameter can undergo severe plastic deformation without failure, whereas brittle fracture is observed for 120 nm sized nano-particles. This is evidence of a critical size under which alumina, at least in the form of nano-particles, cannot be considered as brittle materials even at room temperature and a direct observation of the grinding limit generally observed during ball milling.     

SEM–EDX and XRD characterization of zeolite NaA, synthesized from rice husk and aluminium scrap by different procedures for preparation of the initial hydrogel

A number of investigations have demonstrated that zeolite NaA could be synthesized using Si, extracted from rice husk ash; however, experiments on direct extraction of Si from rice husk (RH) are scarce. The main objective of the present study was to explore the possibility to synthesize high-quality zeolite NaA from RH and waste aluminium cans (as a source of Al), applying different procedures for the preparation of initial hydrogel and a unified procedure for crystallization of zeolite NaA. Products were characterized by SEM–EDX and XRD analyses. The investigation demonstrated that Si could be extracted directly from RH, avoiding the process of RH burning. Practically complete dissolution of Si from RH was achieved by alkali treatment (with 10 % NaOH for 7 h) at boiling temperature and atmospheric pressure, i.e. using refluxing system instead of autoclave for the preparation of Si-gel. Zeolite NaA samples synthesized from such Si-gels were pure, highly crystalline and white. Furthermore, it was found that the direct dissolution of Al in Si-gel did not affect the quality of the final product. Although this investigation was not focused on the mechanism of zeolite NaA crystallization, the results obtained indicated clearly that the history of Si-gel preparation played an important role in the nucleation and growth of zeolite NaA crystals and influenced their yield, size, and shape. Therefore, the optimization of Si-gel preparation procedure has to be considered as essential not only for the economy of the synthesis of NaA from RH, but also for the quality of the final product.