Defect Energies And Entropies From Computer Simulation And Ionic Conductivity Measurements

Ionic conductivity measurements have been made on pure and strontium- and sulphide-doped sodium chloride and the data analysed by means of a non-linear least squares fitting routine. The purpose of this investigation was two-fold. First, the question as to what types of defects occur in NaCl needed to be resolved. Recent work on KCl indicated that a small concentration of Frenkel defects was present on both sub-lattices in addition to Schottky defects, which have been assumed to predominate in alkali halides. Secondly, a wide variety of values for the anion vacancy migration energy have been given in the literature and it was hoped that the present investigation would help to resolve the correct value of this defect energy. The analysis of the data indicated that Schottky defects do indeed predominate in NaCl. A value of 0.744 eV was determined for the anion migration enthalpy.;In addition to this, calculations were carried out with new potentials for SrCl{dollar}\sb2{dollar} and Na{dollar}\sb2{dollar}S using the HADES code. The main purpose of these calculations was to develop potentials to be used in defect calculations of NaCl containing Sr{dollar}\sp{lcub}2+{rcub}{dollar} and S{dollar}\sp{lcub}2-{rcub}{dollar} impurities; however the availability of these potentials made it possible to carry out additional calculations on SrCl{dollar}\sb2{dollar} and Na{dollar}\sb2{dollar}S. Although the problem of low defect migration energies commonly found in defect calculations of fluorites still persisted, some improvements were made with SrCl{dollar}\sb2{dollar}. No defect calculations on Na{dollar}\sb2{dollar}S had been done previously.;An investigation of the quasi-harmonic approximation was carried out with a set of temperature dependent potentials for NaCl, KCl, and KBr. In the past, quasi-harmonic calculations have been undertaken only with potentials developed at 0 K. However, a lattice which is strain-free at 0 K is no longer at equilibrium at higher temperatures. The temperature dependent potentials were developed over a wide temperature range by fitting to the physical properties of the crystal at 50 K intervals and minimizing the bulk lattice strain. The resulting defect energies were compared to values calculated using the potentials of Catlow, Diller, and Norgett developed at 0 K, and additional thermodynamic properties were calculated in the quasi-harmonic approximation

A suggested new bacteriophage genus: “Viunalikevirus”

We suggest a bacteriophage genus, “Viunalikevirus”, as a new genus within the family Myoviridae. To date, this genus includes seven sequenced members: Salmonella phages ViI, SFP10 and ΦSH19; Escherichia phages CBA120 and PhaxI; Shigella phage phiSboM-AG3; and Dickeya phage LIMEstone1. Their shared myovirus morphology, with comparable head sizes and tail dimensions, and genome organization are considered distinguishing features. They appear to have conserved regulatory sequences, a horizontally acquired tRNA set and the probable substitution of an alternate base for thymine in the DNA. A close examination of the tail spike region in the DNA revealed four distinct tail spike proteins, an arrangement which might lead to the umbrella-like structures of the tails visible on electron micrographs. These properties set the suggested genus apart from the recently ratified subfamily Tevenvirinae, although a significant evolutionary relationship can be observed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00705-012-1360-5) contains supplementary material, which is available to authorized users

Antimicrobial resistance in dairy slurry tanks: A critical point for measurement and control

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Formulation Pre-screening of Inhalation Powders Using Computational Atom–Atom Systematic Search Method

The synthonic modeling approach provides a molecule-centered understanding of the surface properties of crystals. It has been applied extensively to understand crystallization processes. This study aimed to investigate the functional relevance of synthonic modeling to the formulation of inhalation powders by assessing cohesivity of three active pharmaceutical ingredients (APIs, fluticasone propionate (FP), budesonide (Bud), and salbutamol base (SB)) and the commonly used excipient, α-lactose monohydrate (LMH). It is found that FP (−11.5 kcal/mol) has a higher cohesive strength than Bud (−9.9 kcal/mol) or SB (−7.8 kcal/mol). The prediction correlated directly to cohesive strength measurements using laser diffraction, where the airflow pressure required for complete dispersion (CPP) was 3.5, 2.0, and 1.0 bar for FP, Bud, and SB, respectively. The highest cohesive strength was predicted for LMH (−15.9 kcal/mol), which did not correlate with the CPP value of 2.0 bar (i.e., ranking lower than FP). High FP–LMH adhesive forces (−11.7 kcal/mol) were predicted. However, aerosolization studies revealed that the FP–LMH blends consisted of agglomerated FP particles with a large median diameter (∼4–5 μm) that were not disrupted by LMH. Modeling of the crystal and surface chemistry of LMH identified high electrostatic and H-bond components of its cohesive energy due to the presence of water and hydroxyl groups in lactose, unlike the APIs. A direct comparison of the predicted and measured cohesive balance of LMH with APIs will require a more in-depth understanding of highly hydrogen-bonded systems with respect to the synthonic engineering modeling tool, as well as the influence of agglomerate structure on surface–surface contact geometry. Overall, this research has demonstrated the possible application and relevance of synthonic engineering tools for rapid pre-screening in drug formulation and design

Elizabeth Hooton (1600-1672) : Une Guerriere De La Paix: Ses Lettres

Through her Letters written to Friends, to her opponents: priests, magistrates, politicians, including the king, Elizabeth Hooton leaves a captivating testimony of her fights for and of her activism in quest of the Truth, Freedom, Justice and equity for all as well as peace on earth and within the Quaker movement. Hers was a fight and quest far from any guided by egoism pure and simple or by personal interest. She was driven by her interest in the common good of all and everywhere. In History of civilizations we have actors who fade away unnoticed or at times are just ignored whereas their contributions to the said civilizations as small as they might be have contributed tremendously in shaping without doubt the same civilizations. Elizabeth Hooton falls within this category of people whose contribution to contemporary English civilization and above all to the feminist movement can be read between the lines of the fragments of these letters; she wrote to her Friends and to the political leaders of England during an era of great changes which radically transformed the English society i.e. 17th Century England. She expresses herself in very caustic terms as a way of affirming the rights to equality of the oppressed woman and other marginals of the society of her time. She anchors her fight on the axis of a universal and Universalist quest for equality, a Quaker ideal

The human motivation of adventure tourism and high risk sport participation

The purpose of the present study was to establish whether sensation seeking, achievement, and social desirability are imp01iant motives for participation in the high risk sport, rock climbing, and for the adventure tourism activity, bungy jumping. In addition, the study sought to establish whether the decision to bungy jump is made on impulse, or after careful consideration, and whether any other possible motives exist for high risk sport and adventure tourism participation. Thirty rock climbers (21 males and 9 females), thirty bungy jumpers (18 males and 12 females), and thirty control subjects (13 males and 17 females) completed a background information questionnaire containing demographic information, a specific impulsive question, and a four-point Likert scale containing reasons for participation or non-participation; Zuckerman's Sensation Seeking Scale, Form V; Nygard and Gjesme's Achievement Motives Scale; and the Marlowe-Crowne Social Desirability Scale. ANOVA results suggest that sensation seeking is an important motive for bungy jumping and rock climbing (especially the thrill seeking and adventure dimension, and the experience seeking dimension), but that there is no difference between these two activities in this motive. The achievement motive was found to be particularly important for rock climbing, but only moderately so for bungy jumping. The need to be socially desirable was not found to be an important motive for either bungy jumping or rock climbing participation, although results from the Likert scale, and individual feedback suggest that more research needs to further investigate the social desirability motive. Results from analysis to the impulsive question indicate that, in general, the decision to bungy jump is made on impulse, while the decision to participate in rock climbing is made with some thought to other factors. Other motivations for high risk sport and adventure tourism that were encountered m the study which should be further investigated, include enjoying the environment; fitness; interest in the technology; helping to achieve other goals for related disciplines; improving holiday quality; and curiosity. Future research investigating the motivations of other adventure tourism activities in relation to gender, age, and cultural differences would be useful

Artificial Womb Technology, Pregnancy and EU Employment Rights

This article considers challenges for the European Union (EU) maternity and pregnancy rights framework when faced with advances in reproductive technology. Specifically, we consider how the introduction of the ‘artificial womb’ technology, an alternative to bodily gestation, would impact the availability of rights that exist under the maternity and discrimination framework. Employment rights in the EU context have already been confronted by the challenges of advancements in reproduction. We use the case law on in vitro fertilization (IVF) and surrogacy as a baseline for unpacking the challenges that ‘artificial wombs’ will bring. This analysis of the legal framework on maternity rights and sex discrimination will highlight potential avenues for integrating this technology and ensuring the continuation of rights for those opting for it. We advocate against the stratification of maternity and pregnancy rights based on the reproductive and gestational choices made by the pregnant person