Kinetic Monte Carlo simulations inspired by epitaxial graphene growth

Graphene, a flat monolayer of carbon atoms packed tightly into a two dimensional hexagonal lattice, has unusual electronic properties which have many promising nanoelectronic applications. Recent Low Energy Electron Microscopy (LEEM) experiments show that the step edge velocity of epitaxially grown 2D graphene islands on Ru(0001) varies with the fifth power of the supersaturation of carbon adatoms. This suggests that graphene islands grow by the addition of clusters of five atoms rather than by the usual mechanism of single adatom attachment. We have carried out Kinetic Monte Carlo (KMC) simulations in order to further investigate the general scenario of epitaxial growth by the attachment of mobile clusters of atoms. We did not seek to directly replicate the Gr/Ru(0001) system but instead considered a model involving mobile tetramers of atoms on a square lattice. Our results show that the energy barrier for tetramer break up and the number of tetramers that must collide in order to nucleate an immobile island are the important parameters for determining whether, as in the Gr/Ru(0001) system, the adatom density at the onset of island nucleation is an increasing function of temperature. A relatively large energy barrier for adatom attachment to islands is required in order for our model to produce an equilibrium adatom density that is a large fraction of the nucleation density. A large energy barrier for tetramer attachment to islands is also needed for the island density to dramatically decrease with increasing temperature. We show that islands grow with a velocity that varies with the fourth power of the supersaturation of adatoms when tetramer attachment is the dominant process for island growth

3D-printed concrete footbridges: An approach to assess the sustainability performance

Digital fabrication with concrete (DFC) is fast becoming an attractive alternative for components (i.e., façades, urban furniture) and structural typologies (i.e., short-span footbridges, columns, floor systems) for which complex geometries derived from particular aesthetical criteria and/or construction time constrictions are governing parameters. Additionally, some authors claim that this process allows improving the sustainability of structures, as less material is necessary compared to traditional concrete solutions, thus reducing greenhouse gas emissions linked to material consumption. Nonetheless, the environmental implications of DFC are still under scrutiny and remain objectively unquantified. In this study, a sustainability assessment model to allow decision-makers to evaluate and compare concrete footbridge alternatives—from the sustainability perspective—including those constructed by means of 3D printed concrete (3DPC) techniques, is presented. The proposed approach is based on the MIVES method. For this purpose, the most representative criteria and indicators of sustainability identified are measured and weighted-aggregated in a decision-making tree. The sustainability index (SI) of each alternative is the outcome derived from the application of the model, and the SI was used as reference for evaluating the alternatives. The sustainability of 3D-printed footbridges is quantified and compared to other concrete-based solutions: traditional reinforced cast-in-place and precast concrete, as traditional solutions, and ultra-high performance precast concrete and textile-reinforced concrete, as innovative alternatives. The results of the analysis lead to conclude that 3D-printed footbridges have positive impacts on environmental and social indicators, but economic indicators still need to be improved to attain a competitive solution. The approach proposed herein to assess the sustainability of footbridges can be extended to other cases and stakeholders' preferences by adapting the components of the method to sensitivities and particular boundary conditions of other scenarios

Knowledge about foot-specific foot falls risk factors and exercise among physiotherapists in the UK and Portugal: a cross-sectional survey

BACKGROUND AND PURPOSE: Foot‐related falls risk factors and specific foot and ankle exercise interventions are within the scope of Physiotherapy, yet little is known about United Kingdom (UK) and Portugal‐based (PT) physiotherapists' self‐perceived knowledge, confidence and practice of such interventions, or perceptions of patients' falls prevention knowledge. The purpose of this study was to assess levels of self‐reported knowledge, confidence, and practices surrounding foot‐specific falls risk and exercise for fall prevention in physiotherapists working in the UK and in Portugal. It also aimed to explore physiotherapists' views about their participants' falls prevention knowledge. METHODS: A self‐report online survey was developed, and pilot tested in both nations. Registered Physiotherapists were invited to participate through their professional associations, social media and snowballing. Mann‐Whitney tests were used to compare mean ranks of ordinal variables between nations and Chi‐square test to assess the independency between pairs of variables. Spearman's correlation coefficient (rs) was used to measure the association between pairs of variables (p < 0.05). RESULTS: 682 physiotherapists participated in the survey [UK n = 229 (mean (SD) age = 43(10) years, 86.9% female]; PT n = 453 (mean (SD) age = 33(9) years, 78.3% female]. Among physiotherapists with a caseload of ≥70% older adults, more PT‐based physiotherapists held postgraduate qualifications (p = 0.01). Most physiotherapists correctly identified generic and foot‐specific risk factors (≥70% of participants for each item). More UK‐based physiotherapists reported always prescribing ankle and foot exercises (42.6% vs. 33%, p =< 0.001) and displayed higher levels of self‐reported confidence surrounding exercise‐based interventions. DISCUSSION: Our sample of UK and Portugal‐based physiotherapists are aware of the contribution of foot‐specific risk factors and exercise to falls prevention, with the former group being more confident in exercise‐based interventions. Both groups of physiotherapists perceived that their older patients had little knowledge about these topics, with UK older adults having slightly better knowledge on generic falls risk factors at first contact. Future studies and strategies for knowledge translation and education in foot health and foot function screening and management for physiotherapists, within a falls prevention scope, may be informed by this study

Formulación de estrategias de marketing mix a partir del estudio del comportamiento del consumidor de leche en la ciudad de Riobamba/Formulation of marketing mix strategies based on the study of milk consumer behavior in the city of Riobamba

El estudio económico de la conducta del consumidor supone teorías de enfoque positivista y normativo. En este contexto las decisiones de consumo se basan no siempre en un modelo racional, considerando además factores de tipo emocional, experiencias que determinan la decisión de compra. El objetivo de este artículo fue formular estrategias de marketing mix a partir del estudio del comportamiento del consumidor de leche en la ciudad de Riobamba. La metodología utilizada se fundamentó en un estudio cuasi experimental que tomó como base un modelo predeterminado que sirvió para diseñar una encuesta que permitiese identificar y evaluar variables determinantes en la conducta de los consumidores. La investigación permitió determinar las preferencias de marcas de leche, nivel de aceptación del precio, tipo de empaque, medios de comunicación y frecuencia de consumo. Los resultados de la investigación permitieron formular estrategias que contribuyen a incentivar el consumo de leche en la población local. The economic study of consumer behavior supposes theories of positivist and normative approach. In this context, consumer decisions are not always based on a rational model, considering factors of an emotional nature, experiences that determine the purchase decision. The objective of this article was to formulate marketing mix strategies based on the study of milk consumer behavior in the city of Riobamba. The methodology used was based on a quasi-experimental study that took as a basis a predetermined model that served to design a survey that would identify and evaluate determinant variables in the behavior of consumers. The investigation allowed to determine the preferences of milk brands, level of acceptance of the price, type of packaging, means of communication and frequency of consumption. The results of the research allowed to formulate strategies that contribute to encourage the consumption of milk in the local population. Palabras clave: comportamiento del consumidor, neuroeconomía, marketing mix. Keywords: consumer behavior, neuroeconomics, marketing mix

Sobre el género Chrysopa Leach, 1815 de la Península Ibérica y Baleares (Insecta, Neuroptera: Chrysopidae)

New data are provided about the species of genus Chrysopa Leach, 1815 recorded in the Iberian Peninsula and the Balearic Islands. Regarding those species for which there were doubtful records or taxonomic questions, almost all the Iberian specimens were studied and compared with material coming from other areas to clarify these questions. So, their presence in Iberian-Balearic fauna, with the corresponding confirmation or correction of certain records, was verified, and the identity of some taxa (species and varieties) was elucidated. The validity of Chrysopa nierembergi Navás, 1908 regard to C. formosa Brauer, 1850 is confirmed, and its Lectotype is designated. Also the Lectotypes of Chrysopa nierembergi var. andreui Navás, 1910 and for Chrysopa nierembergi var. clara Navás, 1915 are designated. Both are considered synonyms of C. nierembergi. Only two of the Iberian records of Chrysopa phyllochroma Wesmael, 1841 are considered as valid, and the presence of Chrysopa dubitans Mclachlan, 1887 in the Iberian fauna is confirmed. The variety Chrysopa nierembergi var. nitens Navás, 1909 is considered as a valid species: Chrysopa nitens Navás, 1909 stat. prom., designating for her Lectotype. The external morphology and male genitalia characters of these five species are discussed, as well some diagnostic and comparative elements between them or with other nearby species. It commented and discussed some characters usually used in the identification of the species of the Chrysopidae family (variability and persistence of integumentary pigmentation of the specimens according to populations and time elapsed since their collection and conservation mode; dilated claws at their base or not). Finally, and until there is no new evidence, the alleged presence of Chrysopa abbreviata Curtis, 1834 and Chrysopa walkeri McLachlan, 1893 in the Iberian fauna is definitely ruled out, since it is based on inaccurate or inconsistent old quotations, not corroborated by new material. The genus Chrysopa is represented in the Iberian-Balearic fauna by ten species, of which the existing information is recorded and compiled, new material is provided, and the key of species of this genus and the maps of its distribution in the Iberian Peninsula and the Balearic Islands are updated.Se aportan nuevos datos sobre las especies del género Chrysopa Leach, 1815 citadas en la Península Ibérica y Baleares. De las especies mencionadas en su fauna sobre las que existían dudas en la veracidad de sus citas o se había cuestionado su validez taxonómica, se ha estudiado y anotado la mayoría del material correspondiente, tanto ibérico como material de comparación de otras zonas, con la intención de dilucidar estas cuestiones. Bien sea para constatar su presencia en su fauna, con la correspondiente confirmación o corrección de ciertas citas, como para verificar la identidad de algunas especies de este género y algunas de sus variedades descritas, con la confirmación o revisión de su identidad taxonómica. Se confirma la validez de Chrysopa nierembergi Navás, 1908 respecto a C. formosa Brauer, 1850 y se designa para ella Lectotipo. También se designa Lectotipo para Chrysopa nierembergi var. andreui Navás, 1910 y para Chrysopa nierembergi var. clara Navás, 1915, ambas son consideradas sinónimas de C. nierembergi. Se dan por válidas solo dos de las citas ibéricas de Chrysopa phyllochroma Wesmael, 1841, y se confirma la presencia de Chrysopa dubitans McLachlan, 1887 en la fauna ibérica. Se eleva a categoría de especie la variedad Chrysopa nierembergi var. nitens Navás,1909, considerándola como especie válida: Chrysopa nitens Navás, 1909 stat. prom., designando para ella Lectotipo. De estas cinco especies se anotan sus caracteres de morfología externa y de genitalia masculina, así como algunos elementos diagnósticos y comparativos entre ellas o con otras especies próximas. Se comentan y se discuten algunos caracteres habitualmente utilizados en la identificación de las especies de Chrysopidae (variabilidad y persistencia de la pigmentación tegumentaria de los ejemplares según poblaciones, tiempo transcurrido desde su recolección y modo de conservación; uñas dilatadas en su base o no). Por último, y hasta que no existan nuevas evidencias, se descarta definitivamente la supuesta presencia de Chrysopa abbreviata Curtis, 1834 y Chrysopa walkeri McLachlan, 1893 en el solar ibérico, ya que está basada en citas antiguas imprecisas o inconsistentes, no corroboradas por nuevo material. El género Chrysopa está representado en la fauna Ibero-Balear por diez especies, de las cuales se anota y recopila la información existente, y se aporta nuevo material, también se actualizan la clave de especies de este género y los mapas de su distribución en la Península Ibérica y Baleares

Nuevos datos sobre algunas especies de crisópidos de la Península Ibérica, islas Baleares e islas Canarias (Insecta, Neuroptera, Chrysopidae)

New data on 41 green-lacewings species belonging to the Iberian, Balearic and Canarian faunas are given. The external morphology and genitalia of Chrysopa nigricostata Brauer, 1850 are re-described, and the erroneous citations given for Spain and Portugal, mostly assigned now to Cunctochrysa cosmia (Navás, 1918), are corrected. The species Chrysopa cosmia Navás, 1918 is confirmed, and its valid status reinstated (previously a later synonymous of Chrysopa nigricostata), and it is transferred to the genus Cunctochrysa, proposing a new combination: Cunctochrysa cosmia (Navás, 1918) n. comb., and a new synonymy: Cunctochrysa cosmia (Navás, 1918)=(Cunctochrysa bellifontensis Leraut, 1988 n. syn.) is now proposed. Based on the single known of Cunctochrysa cosmia and on the material now assigned to this species, its external and genital morphology are re-described, giving an identification key for the three European species of the genus Cunctochrysa, underscoring certain elements to differentiate them from one another, as well from other European species with a similar morphology and coloration (Pseudomallada flavifrons, Chrysopa viridana and specially C. nigricostata). Because of these similarities, some errors in the identification of these European species are detected. This paper draws attention on the possible confusion among these species, and it suggests checking the authenticity of its proposed synonyms. Two new combinations: Pseudomallada subcostalis (McLachlan, 1882) n. comb., and Pseudomallada fortunatus (McLachlan, 1882) n. comb. are proposed.Se aportan nuevos datos de 41 especies de crisópidos de las Faunas Ibérica, Balear y Canaria. Se redescribe la morfología externa y genital de Chrysopa nigricostata Brauer, 1850 y se corrigen sus citas erróneas de España y Portugal, que mayoritariamente se asignan a Cunctochrysa cosmia (Navás, 1918). Se revalida la especie Chrysopa cosmia Navás, 1918 estatus válido restaurado (antes sinónima posterior de Chrysopa nigricostata) y se transfiere al género Cunctochrysa, proponiéndose una nueva combinación: Cunctochrysa cosmia (Navás, 1918) n. comb., y una nueva sinonimia: Cunctochrysa cosmia (Navás, 1918)=(Cunctochrysa bellifontensis Leraut, 1988) n. sin. Sobre el único ejemplar hasta ahora conocido de Cunctochrysa cosmia y el nuevo material ahora a ella asignado, se redescribe su morfología externa y genital, aportándose una clave de identificación para las tres especies europeas del género Cunctochrysa, anotándose nuevos datos para diferenciarlas tanto entre sí, como de otras especies europeas de similar morfología y coloración (Pseudomallada flavifrons, Chrysopa viridana y especialmente C. nigricostata). Por estas similitudes, se detectan algunos errores en la identificación de estas especies, se llama la atención sobre la posible confusión entre estas especies, y se sugiere revisar la autenticidad de sus sinonimias propuestas. Se establecen dos nuevas combinaciones: Pseudomallada subcostalis (McLachlan, 1882) n. comb. y Pseudomallada fortunatus (McLachlan, 1882) n. comb

Nuevos datos sobre algunas especies de Hemeróbidos de la península Ibérica e islas Canarias, incluyendo una nueva especie invasora de origen neotropical en Portugal (Insecta, Neuroptera, Hemerobiidae)

New data on the distribution, biology and phenology of 25 brown lacewings species (Insecta, Neuroptera: Hemerobiidae) of Iberian and Canaries fauna are given. The species Hemerobius bolivari Banks, 1910, widely distributed in the Neotropical Region, is recorded for the first time in Europe as a new invasive species, from specimens collected on Thaumastocoris peregrinus Carpintero & Dellapé, 2006 (Hemiptera: Thaumastocoridae) colonies on Eucalyptus in Lisbon (Portugal). This brown lacewing species, along with Sympherobius gayi Navás, 1910, also known from South America, is the second invasive species of neotropical origin, belonging to this family, that is recorded in the Iberian Peninsula, both from Portugal. We also mention several species that have been seldom recorded in the Iberian Peninsula, and among them Wesmaelius ravus (Withycombe, 1923) is recorded for the second time in the Iberian Peninsula, now from Sierra Nevada (Granada). From samplings made in southern Spain (Malaga, Granada) Micromus angulatus (Stephens, 1836) shows activity as imagoes during winter time (the entire year in the Iberian Peninsula, including this area), and these data seem also to confirm its link to grass vegetation.Se anotan nuevos datos sobre la distribución, biología y fenología de 25 especies de hemeróbidos (Insecta, Neuroptera: Hemerobiidae) de las Faunas Ibérica y Canaria. La especie Hemerobius bolivari Banks, 1910, ampliamente distribuida por la Región Neotropical, se cita por primera vez de Europa como una nueva especie invasora, a partir de ejemplares recolectados en colonias de Thaumastocoris peregrinus Carpintero y Dellapé, 2006 (Hemiptera: Thaumastocoridae:) sobre Eucalyptus en Lisboa (Portugal). Esta especie, junto a Sympherobius gayi Navás, 1910, también originaria de Sudamérica, es la segunda especie invasora de origen neotropical que de esta familia se cita en la Península Ibérica, en este caso también de Portugal. Se mencionan varias especies que han sido muy escasamente citadas en la Península Ibérica, y entre ellas destaca Wesmaelius ravus (Withycombe, 1923), que se cita por segunda vez en la Península Ibérica, en este caso de Sierra Nevada (Granada). A partir de muestreos realizados en el sur de España (Málaga, Granada), se desprende actividad en los imagos de Micromus angulatus (Stephens, 1836) en los meses de invierno (a lo largo de todo el año en la Península Ibérica, incluyendo esta zona ibérica), y estos datos también parecen corroborar su vinculación con la vegetación arvense