Effects of the second virial coefficient on the adiabatic lapse rate of dry atmospheres

We study the effect of the second virial coefficient on the adiabatic lapse rate of a dry atmosphere. To this end, we compute the corresponding adiabatic curves, the internal energy, and the heat capacity, among other thermodynamic parameters. We apply these results to Earth, Mars, Venus, Titan, and the exoplanet G1 851d, considering three physically relevant virial coefficients in each case: the hard-sphere, van der Waals, and the square-well potential. These examples illustrate under which atmospheric conditions the effect of the second virial coefficient is relevant. Taking the latter into account yields corrections towards the experimental values of the lapse rates of Venus and Titan in some instances.Comment: 12 pages, 8 figures. Comments are welcom

Size-controlled and redox-responsive supramolecular nanoparticles

Control over the assembly and disassembly of nanoparticles is pivotal for their use as drug delivery vehicles. Here, we aim to form supramolecular nanoparticles (SNPs) by combining advantages of the reversible assembly properties of SNPs using host–guest interactions and of a stimulus-responsive moiety. The SNPs are composed of a core of positively charged poly(ethylene imine) grafted with β-cyclodextrin (CD) and a positively charged ferrocene (Fc)-terminated poly(amidoamine) dendrimer, with a monovalent stabilizer at the surface. Fc was chosen for its loss of CD-binding properties when oxidizing it to the ferrocenium cation. The ionic strength was shown to play an important role in controlling the aggregate growth. The attractive supramolecular and repulsive electrostatic interactions constitute a balance of forces in this system at low ionic strengths. At higher ionic strengths, the increased charge screening led to a loss of electrostatic repulsion and therefore to faster aggregate growth. A Job plot showed that a 1:1 stoichiometry of host and guest moieties gave the most efficient aggregate growth. Different stabilizers were used to find the optimal stopper to limit the growth. A weaker guest moiety was shown to be less efficient in stabilizing the SNPs. Also steric repulsion is important for achieving SNP stability. SNPs of controlled particle size and good stability (up to seven days) were prepared by fine-tuning the ratio of multivalent and monovalent interactions. Finally, reversibility of the SNPs was confirmed by oxidizing the Fc guest moieties in the core of the SNPs

Characterization of a high strain composite material

L'Garde has designed and developed a high-strain composite material consisting of car- bon FIbers embedded in a silicone matrix. The behavior of this material is significantly different from standard composites and the paper presents special test methods to measure the properties of this material. It is found that rule of mixtures estimates are quite accurate for the longitudinal moduli in tension and bending, but less accurate for compression. The Poisson's ratio prediction is also not accurate. Regarding the strength of the composite, it is found that conservative predictions of tensile and compressive strengths can be obtained respectively from the Weibull distribution of the strength of a single fiber combined with a simple bundle theory, and the elastic fiber microbuckling stress

Nuevas tecnologías y aprendizaje matemático en niños con síndrome de down: generalización para la autonomía

El presente trabajo analiza el efecto del uso de materiales multimedia en el aprendizaje de contenidos matemáticos y sus posibilidades de generalización a personas con síndrome de Down. Dos grupos de niños fueron instruidos, con distintas metodologías de enseñanza, en los principios de conteo y cantidad. Mientras un grupo trabajó con material multimedia, el otro lo hizo con una metodología tradicional de lápiz y papel. Tras el proceso de enseñanza, ambos grupos fueron evaluados mediante una tarea que simulaba una situación de compra. Los resultados sugieren un claro efecto facilitador de la metodología multimedia en la generalización de los conceptos y habilidades básicos de conteo en niños con síndrome de Down.The present study aims to explore the effect of using multimedia material on the learning and generalization of mathematical contents in Down syndrome children. Two groups of children were trained in the principles of counting and cardinality. One group learned by means of a computer-assisted teaching and the other did it by using a paperand-pencil-based methodology. After the teaching process, both groups were assessed with a task pretending a shopping setting. The results strongly suggest an effect of multimedia teaching to facilitate the generalization of the concepts and skills learned by Down syndrome children

Template-based methodology for the simulation of intracorneal segment ring implantation in human corneas

Keratoconus is an idiopathic, non-inflammatory and degenerative corneal disease characterised by a loss of the organisation in the corneal collagen fibrils. As a result, keratoconic corneas present a localised thinning and conical protrusion with irregular astigmatism and high myopia that worsen visual acuity. Intracorneal ring segments (ICRSs) are used in clinic to regularise the corneal surface and to prevent the disease from progressing. Unfortunately, the post-surgical effect of the ICRS is not explicitly accounted beforehand. Traditional treatments rely on population-based nomograms and the experience of the surgeon. In this vein, in silico models could be a clinical aid tool for clinicians to plan the intervention, or to test the post-surgical impact of different clinical scenarios. A semi-automatic computational methodology is presented in order to simulate the ICRS surgical operation and to predict the post-surgical optical outcomes. For the sake of simplicity, circular cross section rings, average corneas and an isotropic hyperelastic material are used. To determine whether the model behaves physiologically and to carry out a sensitivity analysis, a (Formula presented.) full-factorial analysis is carried out. In particular, how the stromal depth insertion, horizontal distance of ring insertion (hDRI) and diameter of the ring’s cross section ((Formula presented.)) are impacting in the spherical and cylindrical power of the cornea is analysed. Afterwards, the kinematics, mechanics and optics of keratoconic corneas after the ICRS insertion are analysed. Based on the parametric study, we can conclude that our model follows clinical trends previously reported. In particular and although there is an improvement in defocus, all corneas presented a change in their optical aberrations. The stromal depth insertion is the parameter that affects the corneal optics the most, whereas hDRI and (Formula presented.) are less important. Not only that, but it is almost impossible to achieve an optimal trade-off between spherical and cylindrical correction. Regarding the mechanical behaviour, inserting the rings at 65% depth or above will cause the cornea to slightly bend. This abnormal stress distribution greatly distorts the corneal optics and, more importantly, could be the cause of clinical problems such as corneal extrusion. Not only that, but our model also supports that rings are acting as restraint elements which relax the stresses of the corneal stroma in the cone of the disease. However, depending on the exact spatial location of the keratoconus, the insertion of rings could promote its evolution instead of preventing it. ICRS inserted deeper will prevent keratoconus in the posterior stroma from growing (relaxation of posterior surface), but will promote its growing if they are located in the anterior surface (increment of stress). In conclusion, the methodology proposed is suitable for simulating long-term mechanical and optical effects of ICRS insertion

Critical Thinking About Learning Styles: Challenging Literature Reviews

As educators, we encourage students to think critically and to question what we read in research findings. Should we not take the same perspective when reviewing literature for our own purposes? For example, learning styles is a ubiquitous concept that is bandied about by everyone from educators to legislators, but a myriad of controversy and criticism surrounds the operationalization of learning styles and its application to effective teaching and learning. This paper discusses a variety of issues concerning the concept of learning styles and includes diverse conceptualizations; questions concerning validity and reliability of instruments used to identify learning styles; construction of instructional designs; and reports the charges of bias that researchers make against each other’s work. The authors suggest that these topics and issues be used to form guiding questions when reviewing learning styles literature

Quality specification and control of a point cloud from a TLS survey using ISO 19157 standard

This paper presents an application of the ISO 19157 framework to the case of a point cloud (PC) representing a heritage asset whose purpose is to serve specific use cases that could be managed in a building information modeling (BIM) environment. The main contribution of this study is to clarify the relationships between the different parts of the ISO 19157 framework applied to heritage building information modeling (HBIM) products derived from terrestrial laser scanner (TLS) surveys by means of a running example. This paper presents a proposal to evaluate, control and report on the quality of the TLS survey of the Ariza Bridge (a 16th century construction). In order to achieve this objective the data quality specifications that must be met are defined by describing and identifying the requirements of five use cases of the data product: 3D visualization, location transfer, measurement, plane generation and absolute positioning. The specifications, according to ISO 19157, are formalized by selecting the data quality element to be measured, its scope, the measure used and the level of conformity necessary for the element to be accepted. In addition, the control methods for each quality element are proposed.Junta de Andalucia PAIDI-TEP-164Universidad de Jae?n POAIUJA 21-22 Universidad de Jaen / CBUA Universidad de Jaen PAIDI-TEP-164 POAIUJA 21-22 TEP164_202

Selective voluntary forgetting in young and older adults

Aging is thought to involve a decline in executive-control capacities, although evidence regarding this claim is not always clear. Thus, although studies exist that suggest impoverished inhibitory memory control in older adults relative to younger adults, experiments with the list-method direct forgetting procedure have mostly failed to show adult-age differences in voluntary forgetting. In the present study we aimed to further study this issue by comparing young-old and young adults’ performance with the selective directed forgetting (SDF) procedure, which we assumed to involve higher demands of executive control than the standard nonselective procedure. Thus, on the basis of previous studies showing that a critical factor in finding adult-age differences in executive-control tasks is the overall challenge posed by the tasks, we predicted less SDF in older adults than in younger adults. Supporting our hypothesis, across three experiments we show evidence of older adults’ impoverished capacity to voluntarily forget episodic memories, although only when the task requires selective forgetting. Ours join other findings to suggest that sensitiveness to detect adult-age differences in cognitive control may strongly depend on the executive-control demands imposed by tasks

La investigación escolar en la construcción de explicaciones acerca de la transmisión de caracteres hereditarios. sistematización de la unidad didáctica ¡moscas!... a enseñar herencia

El presente trabajo expondrá el desarrollo significativo respecto a conceptos, procedimientos y actitudes referidos a la herencia de caracteres hereditarios, que alcanzaron los estudiantes del grado octavo del IEDIT Rodrigo de Triana, en un periodo de tres meses en el año 2008, durante el cual se ejecutó el diseño, aplicación y sistematización de la unidad didáctica ¡Moscas! a enseñar herencia. En esta experiencia educativa se adoptaron los postulados del Enfoque de Enseñanza por Investigación Dirigida y el instrumento metodológico de Investigación Acción, donde los estudiantes organizados en equipos de trabajo abordaron una pregunta problema para desarrollar una investigación escolar, bajo la atenta dirección de las docentes, quienes corroboraron un cambio procedimental, conceptual y actitudinal en los estudiantes del grado 803