643 research outputs found
Genome size unaffected by moderate changes in climate and phosphorus availability in Mediterranean plants
Nuclear DNA amount has been assessed in a set of 6 Mediterranean plant species including subshrubs, shrubs and trees (Dorycnium pentaphyllum Scop., Erica multiflora L., Fumana ericoides (L.) Webb, Globularia alypum L., Pinus halepensis Mill and Rosmarinus officinalis L.). Genome size values have been assessed by flow cytometry from plants growing in their natural habitats, in plots with a particular experimental design to measure the effects of drought and warming and also with different phosphorus (P) concentration in soil. 2C values have been fairly constant in all the species studied under all conditions. These results, which provide first records of DNA content in all the studied species except for P. halepensis, suggest that moderate changes in climate such as a 0.73°C warming or a drought consisting of 19% decrease in soil moisture on an average of 7 years and the consequent changes in the soil availability of such an essential element as P (ranging from 80 to 160 g/g) do not affect genome size stability, at least not by producing rapid and significant variations.Key words: C-value, drought, Mediterranean plants, nuclear DNA amount, phosphorus, warming
Creative innovation in Spanish construction firms
"This material may be downloaded for personal use only. Any other use requires prior permission of the American Society of Civil Engineers"Small and medium-sized contractors are characterized by organizational structures that are highly focused on control. As a result, employees concentrate on day-to-day activities with little time or motivation to generate creative ideas. Generally, the technological improvements of these companies arise as a result of problem-solving at the construction site. Nevertheless, the actual status quo is changing. In fact, some Spanish public agencies are already considering innovation as an added value in public procurement; thus, large contractors are starting to systemize their innovative efforts. This means that small and medium-sized enterprises must modify their attitudes towards innovation in order to sustain their competitiveness. The implementation of a system that enhances innovation and acquisition of knowledge may be the solution to overcome this disadvantage. The authors analyzed the implementation of an innovation management system in a Spanish construction firm of medium size for nine years. The system builds on a set of processes aimed to generate innovation projects that allow the contractor to document the innovation, not only for internal purposes related to knowledge management, but also for external ones associated with obtaining better results in public tenders. These processes are: (a) technology watch; (b) creativity; (c) planning and executing innovation projects; (d) technology transfer; and (e) protection of results. The last step is the feedback of the entire process through the assessment of the final outcomes. The implementation of the innovation system is ensured within the organization, through training of personnel, participation of stakeholders and encouragement of the innovation culture.The research reported in this paper was partially funded by the Universidad Catolica del Maule (UCM) [Project Mejoramiento de la Calidad y Equidad de la Educacion Superior (MECESUP)-UCM0205], the Spanish Ministry of Infrastructure (Project 2004-36), and the Universitat Politecnica de Valencia (UPV) (Contract UPV-2008-0629). Francisco Vea, Ricardo Lacort, and Manuel Civera are thanked for their help and support throughout the implementation of the system. Dr. Debra Westall is thanked for revising the text.Yepes, V.; Pellicer Armiñana, E.; Fernando Alarcón, L.; Correa Becerra, CL. (2015). Creative innovation in Spanish construction firms. Journal of Professional Issues in Engineering Education and Practice. 141:04015006-1-04015006-10. https://doi.org/10.1061/(ASCE)EI.1943-5541.0000251S04015006-104015006-1014
A model for identifying owner's needs in the building life cycle
Building life cycle is a process which covers not only the construction phase but also the feasibility, the design and the operation phases. Identifying the owner s needs in all phases of this process is of paramount importance for achieving satisfactory results for the building project. Additionally, the owner s needs should be fulfilled by the work scope of every stakeholder involved in the project. Nevertheless, these needs are not always adequately considered in building projects. Thus, the purpose of the research reported in this paper has been to develop a model that allows for the identification of the owner s needs in all phases of the building life cycle. The article presents a six level classification system for the information required in the project and a two-dimensional model that maps the life cycle and the logical actions to be undertaken in each phase. The model has been corroborated and improved by applying the Delphi technique to a panel of ten experts in two rounds. The practical use of the model is through the systematic application of a series of questionnaires built upon the information classification system for determining the owner s needs. The paper details the operation phase of the model as an illustrative example and a case study on a residential building project of twelve apartments in Spain.This research was partially funded by the J. Gomez-Cerezo Foundation (Spain) and the Spanish Ministry of Infrastructure (grant 2004-36). The authors thank the ten experts who participated in the Delphi study and Dr Debra Westall who thoroughly revised the text.Alshubbak, A.; Pellicer, E.; Catalá Alís, J.; Teixeira, JM. (2015). A model for identifying owner's needs in the building life cycle. Journal of Civil Engineering and Management. 21(8):1046-1060. doi:10.3846/13923730.2015.1027257S1046106021
Anodic formation of self-organized Ti(Nb,Sn) oxide nanotube arrays with tuneable aspect ratio and size distribution
This is the author's version of a work that was accepted for publication in Electrochemistry communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Electrochemistry communications, [33,(2013)] DOI10.1016/j.elecom.2013.04.023).In the present communication one-step anodization is used to prepare large arrays of self-assembled Ti(Nb,Sn) oxide nanotubes on Ti-Nb-Sn alloy. Tuneable nanoscale geometries (unimodal vs. bimodal size distribution with variable length/diameter ratios) can be controllably achieved by varying the anodization conditions, which are highly desirable for enhanced functionalities in widespread applications
Versatile quadrature antenna for precise control of large electron spin ensembles in diamond
We present an easily reproducible inexpensive microwave antenna that can
generate a strong and homogeneous magnetic field of arbitrary polarization,
which enables fast and coherent control of electron spins over a large volume.
Unlike preceding works, we present a resonant antenna that maintains its
resonant behaviour regardless of the proximity of other experimental hardware
components. This robustness is crucial as it enables, amongst others, using
microscope objectives with short working distances to perform wide field
imaging/sensing with bulk diamonds. The antenna generates a magnetic field
strength of 22.3 A/m for 1 W total driving power, which doubles the power
efficiency compared with previously reported patch antenna designs. The
magnetic field homogeneity in a volume of ,
and is within 6\%, 8\% and 13\%, respectively. The antenna has
a full width at half maximum bandwidth of 160 MHz and its resonant
frequency can be tuned over a 400 MHz range via four capacitors or varactors.
The antenna has been tested and found to remain within safe handling
temperatures during continuous-wave operation at 8 W. The files required to
reproduce this antenna, which can be built on a standard and affordable double
sided PCB, are provided open-source. This work facilitates a robust and
versatile piece of instrumentation, being particularly appealing for
applications such as high sensitivity magnetometry and wide field
imaging/sensing with Nitrogen Vacancy centers
Benchmarking the performance of a low-cost Magnetic Resonance Control System at multiple sites in the open MaRCoS community
Purpose: To describe the current properties and capabilities of an
open-source hardware and software package that is being developed by many sites
internationally with the aim of providing an inexpensive yet flexible platform
for low-cost MRI. Methods: This paper describes three different setups from 50
to 360 mT in different settings, all of which used the MaRCoS console for
acquiring data, and different types of software interfaces (custom-built GUI or
PulSeq overlay) to acquire the data. Results: Images are presented from both
phantoms and in vivo from healthy volunteers to demonstrate the image quality
that can be obtained from the MaRCoS hardware/software interfaced to different
low-field magnets. Conclusions: The results presented here show that a number
of different sequences commonly used in the clinic can be programmed into an
open-source system relatively quickly and easily, and can produce good quality
images even at this early stage of development. Both the hardware and software
will continue to develop, and it is an aim of this paper to encourage other
groups to join this international consortium.Comment: 9 pages, 10 figures, comments welcom
Determination of the high-pressure crystal structure of BaWO4 and PbWO4
We report the results of both angle-dispersive x-ray diffraction and x-ray
absorption near-edge structure studies in BaWO4 and PbWO4 at pressures of up to
56 GPa and 24 GPa, respectively. BaWO4 is found to undergo a pressure-driven
phase transition at 7.1 GPa from the tetragonal scheelite structure (which is
stable under normal conditions) to the monoclinic fergusonite structure whereas
the same transition takes place in PbWO4 at 9 GPa. We observe a second
transition to another monoclinic structure which we identify as that of the
isostructural phases BaWO4-II and PbWO4-III (space group P21/n). We have also
performed ab initio total energy calculations which support the stability of
this structure at high pressures in both compounds. The theoretical
calculations further find that upon increase of pressure the scheelite phases
become locally unstable and transform displacively into the fergusonite
structure. The fergusonite structure is however metastable and can only occur
if the transition to the P21/n phases were kinetically inhibited. Our
experiments in BaWO4 indicate that it becomes amorphous beyond 47 GPa.Comment: 46 pages, 11 figures, 3 table
The Role of Repeated Exposure to Multimodal Input in Incidental Acquisition of Foreign Language Vocabulary
Prior research has reported incidental vocabulary acquisition with complete beginners in a foreign language (FL), within 8 exposures to auditory and written FL word forms presented with a picture depicting their meaning. However, important questions remain about whether acquisition occurs with fewer exposures to FL words in a multimodal situation and whether there is a repeated exposure effect. Here we report a study where the number of exposures to FL words in an incidental learning phase varied between 2, 4, 6, and 8 exposures. Following the incidental learning phase, participants completed an explicit learning task where they learned to recognize written translation equivalents of auditory FL word forms, half of which had occurred in the incidental learning phase. The results showed that participants performed better on the words they had previously been exposed to, and that this incidental learning effect occurred from as little as 2 exposures to the multimodal stimuli. In addition, repeated exposure to the stimuli was found to have a larger impact on learning during the first few exposures and decrease thereafter, suggesting that the effects of repeated exposure on vocabulary acquisition are not necessarily constant
Modelo para la innovación sistemática en empresas constructoras
Los motivos que impulsan a las empresas constructoras a innovar, así como los procedimientos que utilizan, no han sido suficientemente explorados hasta el momento en la literatura sobre gestión de la construcción. Este artículo describe los cómos y por qués que respaldan el impulso innovador en una empresa constructora. El método de investigación se fundamenta en la validación de un modelo desarrollado mediante un estudio de caso; éste se centra en una empresa constructora de tamaño medio que implementó y certificó un sistema de gestión de la innovación, según lo establecido en la norma española UNE 166002. Los estudios desarrollados por los autores durante cinco años generaron un conjunto de 18 proposiciones que definen un modelo explicativo de la gestión de la innovación. Este artículo reporta la validación externa del modelo por medio de un conjunto de entrevistas, cuyos resultados corroboran plenamente 15 de las proposiciones planteadas. Los principales inductores de innovación en las empresas constructoras son los problemas técnicos que aparecen en obra, los requerimientos de los clientes y la alta dirección de la empresa. Las oportunidades de innovación se identifican como resultado del examen de los procesos internos de la empresa, de las obras y del entorno. Identificar, desarrollar y transferir una solución innovadora requiere la implantación de la vigilancia tecnológica y de la gestión del conocimiento en la organización. Finalmente, la investigación concluye que el principal beneficio de la gestión de la innovación es el incremento de la capacidad técnica de la empresa, mientras que las dos principales barreras para la innovación son la priorización de los procesos productivos y la falta de apoyo de los dirigentes de la empresa.Eugenio Pellicer; Yepes Piqueras, V.; Correa Becerra, CL.; Alarcon, L. (2014). Modelo para la innovación sistemática en empresas constructoras. Journal of Construction Engineering and Management. 140(4):40140011-40140018. doi:10.1061/(ASCE)CO.1943-7862.0000468S4014001140140018140
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