Inactivation kinetics of adenovirus serotype 2 with monochloramine

The effect of pH (6-10), temperature (10-30 degrees C), disinfectant concentration (1-11mg/l as Cl(2)), and ammonia nitrogen-to-chlorine molar ratio (1.3-52) on the inactivation kinetics of adenovirus serotype 2 with monochloramine was investigated by performing batch-reactor experiments with synthetic 0.01M buffer (phosphate or borate) solutions. The inactivation kinetics was independent of monochloramine concentration and ammonia nitrogen-to-chlorine molar ratio but had strong pH dependence, with the rate of inactivation decreasing with increasing pH. The kinetics at pH 6 and 8 were consistent with pseudo-first-order kinetics, while curves at pH 10 were characterized by a lag phase followed by a pseudo-first-order phase. The rate of inactivation increased with increasing temperature-activation energies of 56.5kJ/mole (pH 8) and 72.6kJ/mole (pH 10). The results obtained in this study revealed that monochloramine disinfection might not generally provide adequate control of adenoviruses in drinking water at high pH and low temperature.     

Optimization of subtractive-transformative hybrid processes supported by the technological heredity concept

This paper presents the optimization procedure of a hybrid removal-forming type process based on the minimum energy consumption and demanded surface roughness which is supported by the analysis of transformation of the surface and sublayer properties termed as the technological heredity. The experimental investigation covers an alloy steel hardened to 35 HRC and 55 HRC which was initially turned using coated carbide and CBN tools and subsequently burnished to produce surfaces with Ra roughness parameter of about 0.15 μm. The modifications of the initial surface profiles, microstructure and microhardness of the sublayer were determined and relevant technological limits are selected.     

Biparametric Models for Elastic Wedge Foundation

In this paper, some biparametric models for an elastic foundation are proposed. It is assumed that the foundation has the shape of the wedge. The modeling procedure starts from the linear elasticity equations into which we introduce some simplifying assumptions based on the conceptions of decay functions. The simplified models are described by the ordinary differential equations. Stationary and nonstationary Green’s functions for the foundation considered are obtained by applying the Hankel and Laplace transform methods. An example of the interaction between the rigid plate and the elastic wedge foundation is studied.     

Kynurenine Pathway of Tryptophan Metabolism in Migraine and Functional Gastrointestinal Disorders

Migraine, the leading cause of disability in the population aged below 50, is associated with functional gastrointestinal (GI) disorders (FGIDs) such as functional nausea, cyclic vomiting syndrome, and irritable bowel syndrome (IBS). Conversely, changes in intestinal GI transit may cause diarrhea or constipation and are a component of the autonomic symptoms associated with pre- and post-dorsal phases of migraine attack. These mutual relationships provoke a question on a common trigger in migraine and FGIDs. The kynurenine (l-kyn) pathway (KP) is the major route for l-tryptophan (l-Trp) metabolism and transforms l-Trp into several neuroactive compounds. Changes in KP were reported in both migraine and FGIDs. Migraine was largely untreatable, but several drugs approved lately by the FDA, including monoclonal antibodies for calcitonin gene-related peptide (CGRP) and its receptor, create a hope for a breakthrough in migraine treatment. Derivatives of l-kyn were efficient in pain relief with a mechanism including CGRP inhibition. KP products are important ligands to the aryl hydrocarbon receptor (AhR), whose activation is implicated in the pathogenesis of GI and migraine. Toll-like receptors (TLRs) may play a role in migraine and IBS pathogeneses, and KP metabolites detected downstream of TLR activation may be an IBS marker. The TLR4 signaling was observed in initiating and maintaining migraine-like behavior through myeloid differentiation primary response gene 88 (MyD88) in the mouse. The aim of this review is to justify the view that KP modulation may provide common triggers for migraine and FGIDs with the involvement of TLR, AhR, and MyD88 activation.     

Fabrication of nanoporous TiO2 by electrochemical anodization

The formation of self-organized porous titania is achieved by electrochemical anodization under a potentiostatic regime. Anodic titanium oxide (ATO) was fabricated by a three-step self-organized anodization of the Ti foil in an ethylene glycol electrolyte containing 0.38 wt% of NH₄F and 1.79 wt% of H₂O. Anodizing was carried out at the constant cell potential ranging from 30 to 70 V at the temperature of 20 °C. It was found that nanoporous TiO₂ arrays can be obtain only after a short duration of the third step (10 min). The influence of anodizing potential on the structural parameters of porous anodic titania including pore diameter, interpore distance, wall thickness, porosity and pore density was extensively studied. The linear dependencies between interpore distance, pore diameter and wall thickness upon the anodizing potential were found. The regularity of pore arrangement was monitored qualitatively by fast Fourier transforms (FFTs) of top-view FE-SEM images. It was found that the best arrangement of nanopores is observed at 40 V. This finding was confirmed by the analysis of pore circularity. The highest circularity of pores was observed once again at 40 V.     

Quantitative image analysis of polyurethane/carbon nanotube composite micostructures

Polyurethane/carbon nanotube (PUR/CNTs) composites are much more functional than pure polyurethanes. High intensity ultrasonic agitation was applied while preparing a mixture of multiwall carbon nanotubes and a monomer. The monomer/MWNT complexes were used to prepare PUR/CNTs nanocomposites. This paper describes the application of quantitative image analysis to characterise the microstructure of the monomer and segmented polyurethane with carbon nanotubes (CNTs). Stereological parameters chosen for analysis were used to evaluate the CNTs' dispersion in the monomer complex and the degree of matrix phase separation in the nanocomposites examined. The nanoparticles induced changes in the structure of the hard and soft domains in the polyurethane matrix and influenced thermal and mechanical properties of the material. Due to the introduction of the nanotubes in the polyurethane matrix, the physical size and glass transition temperature of hard domains increased while the tensile strength and storage modulus decreased.     

Characterization of Photoluminescent (Y1–xEux)2O3 Thin Films Prepared by Metallorganic Chemical Vapor Deposition

The purpose of this study was to identify and correlate the microstructural and luminescence properties of europium-doped Y₂O₃ (Y_{1– x} Eu _x )₂O₃ thin films deposited by metallorganic chemical vapor deposition (MOCVD), as a function of deposition time and temperature. The influence of deposition parameters on the crystallite size and microstructural morphology were examined, as well as the influence of these parameters on the photoluminescence emission spectra. (Y_{1– x} Eu _x )₂O₃ thin films were deposited onto (111) silicon and (001) sapphire substrates by MOCVD. The films were grown by reacting yttrium and europium tris(2,2,6,6-tetramethyl–3,5-heptanedionate) precursors with an oxygen atmosphere at low pressures (5 torr (1.7 × 10³ Pa)) and low substrate temperatures (500°–700°C). The films deposited at 500°C were smooth and composed of nanocrystalline regions of cubic Y₂O₃, grown in a textured [100] or [110] orientation to the substrate surface. Films deposited at 600°C developed, with increasing deposition time, from a flat, nanocrystalline morphology into a platelike growth morphology with [111] orientation. Monoclinic (Y_{1– x} Eu _x )₂O₃ was observed in the photoluminescence emission spectra for all deposition temperatures. The increase in photoluminescence emission intensity with increasing postdeposition annealing temperature was attributed to the surface/grain boundary area-reduction effect.     

Field-Assisted Sintering of Nanocrystalline Titanium Nitride

Nanosized TiN powder was densified via field-assisted sintering at temperatures of 1150°–1350°C and a pressure of 66 MPa under vacuum. A maximum relative density of ∼97% and a maximum mean grain size of 150–200 nm were obtained. Densification and microstructural evolution have been discussed, in terms of superplasticity and electric-field effects.     

Photo‐induced Charge Transfer and Relaxation of Persistent Charge Carriers in Polymer/Nanocrystal Composites for Applications in Hybrid Solar Cells

The photo‐induced charge transfer and the dynamics of persistent charge carriers in blends of semiconducting polymers and nanocrystals are investigated. Regioregular poly(3‐hexylthiophene) (P3HT) is used as the electron donor material, while the acceptor moiety is established by CdSe nanocrystals (nc‐CdSe) prepared via colloidal synthesis. As a reference system, organic blends of P3HT and [6,6]‐phenyl C₆₁‐butyric acid methyl ester (PCBM) are studied as well. The light‐induced charge transfer between P3HT and the acceptor materials is studied by photoluminescence (PL), photo‐induced absorption (PIA) and light‐induced electron spin resonance spectroscopy (LESR). Compared to neat P3HT samples, both systems show an intensified formation of polarons in the polymer upon photo‐excitation, pointing out successful separation of photogenerated charge carriers. Additionally, relaxation of the persistent charge carriers is investigated, and significant differences are found between the hybrid composite and the purely organic system. While relaxation, reflected in the transient signal decay of the polaron signal, is fast in the organic system, the hybrid blends exhibit long‐term persistence. The appearance of a second, slow recombination channel indicates the existence of deep trap states in the hybrid system, which leads to the capture of a large fraction of charge carriers. A change of polymer conformation due to the presence of nc‐CdSe is revealed by low temperature LESR measurements and microwave saturation techniques. The impact of the different recombination behavior on the photovoltaic efficiency of both systems is discussed.