Regular Queries on Graph Databases

Graph databases are currently one of the most popular paradigms for storing data. One of the key conceptual differences between graph and relational databases is the focus on navigational queries that ask whether some nodes are connected by paths satisfying certain restrictions. This focus has driven the definition of several different query languages and the subsequent study of their fundamental properties. We define the graph query language of Regular Queries, which is a natural extension of unions of conjunctive 2-way regular path queries (UC2RPQs) and unions of conjunctive nested 2-way regular path queries (UCN2RPQs). Regular queries allow expressing complex regular patterns between nodes. We formalize regular queries as nonrecursive Datalog programs with transitive closure rules. This language has been previously considered, but its algorithmic properties are not well understood. Our main contribution is to show elementary tight bounds for the containment problem for regular queries. Specifically, we show that this problem is 2EXPSPACE-complete. For all extensions of regular queries known to date, the containment problem turns out to be non-elementary. Together with the fact that evaluating regular queries is not harder than evaluating UCN2RPQs, our results show that regular queries achieve a good balance between expressiveness and complexity, and constitute a well-behaved class that deserves further investigation

Inelastic Effective Length Factor of Nonsway Reinforced Concrete Columns

[EN] This paper proposes a new equation for the effective length factor k-factor for reinforced concrete columns in braced frames. The new formula is valid both for normal and high-strength concrete. The equation was obtained from a sensitivity analysis performed on a two-dimensional nonlinear finite-element numerical model that takes into account the inelastic behavior of the concrete columns cracking, yielding, and second order effects. The numerical model was calibrated with 44 experimental tests performed by the writers¿ research group. A comparative study was carried out between the numerical model and different national design codes, displaying important differences with respect to all of them: the ACI code from 37 to 3%, the Spanish code EHE from 26 to 9.26%, and the Eurocode 2 from 14 to 14%. It was decided to propose two additional simplified equations: one for checking and the second for design.The authors wish to express their sincere gratitude to the Spanish Ministerio de Fomento for help provided through project 13-12-2001 and Ministerio de Educación through BIA2005-255.Bendito, A.; Romero, ML.; Bonet Senach, JL.; Miguel Sosa, P.; Fernández Prada, MÁ. (2009). Inelastic Effective Length Factor of Nonsway Reinforced Concrete Columns. Journal of Structural Engineering. 135(9):1034-1039. https://doi.org/10.1061/(ASCE)0733-9445(2009)135:9(1034)S10341039135

Optical accelerometer for seismic measurement

In this work we present an optical accelerometer based in a cantilever beam attached to a fiber Bragg grating (FBG), which can be applied to the seismic and geological fields. This device main characteristics are a high strain along the FBG and a wide operational frequency range. The accelerometer can be easily modeled as a mass block and a fiber optic attached at the cantilever beam tip, the FBG length varies due to the movement of the mass caused by the vertical vibrations. The frequency response range has been enhanced and it was achieved a natural frequency of 242.4 Hz

Splines generalizados y solución nodal exacta en el método de elementos finitos

This paper discusses a method for constructing generalized splines, which is based on a matrix or structural interpretation of the mathematical theory on these functions. It is suggested throughout the paper that both the terminology and the methods of analysis in structures and strength of materials are very natural and, therefore, apt for this field of splines. The proposed method allows a wide range of splines to be addressed by means of a single and simple methodology: changing the characteristics of the spline from some subintervals to others (modification of weights, tension parameters, etc.), different conditions of interpolation in different nodes, etc. A noteworthy contribution is that new conditions of interpolation are considered, which are defined as individual actions (loads). Furthermore, it is found and shown that the solution of one-dimensional boundary value problems using the finite elements method is exact at the nodal points when certain spaces of finite dimension approximation engendered by generalized splines are used. The concept of equivalent action is developed as a generalization of the notion of equivalent nodal action (equivalent nodal loads). Finally, an illustration is given of how the developed methodology, based on the aforesaid matrix interpretation, can be applied, including examples of splines in the field of graphics, analysis of continuous beams on an elastic foundation, subjected to bending moment and tension or compression, and in dynamic problems.Se desarrolla en este trabajo un método de construcción de splines generalizados que está basado en una interpretación matricial o estructural de la teoría matemática de dichas funciones. Se sugiere, a lo largo del desarrollo realizado, que tanto la terminología como los métodos de análisis en cálculo de estructuras y resistencia de materiales son muy naturales y, por tanto, idóneos para este campo de los splines. El método propuesto permite abordar, con una única y sencilla metodología, el tratamiento de tipos de splines muy diferentes.cambio de las características del spline de unos subintervalos a otros (modificación de pesos, parámetros de tensión, etc.), diferentes condiciones de interpolación en los distintos nodos, etc. Se destaca como aportación de interés la consideración de nuevas condiciones de interpolación definidas como acciones de tipo puntual (cargas). Asimismo, se interpreta y demuestra que la solución de problemas de contorno unidimensionales por el método de elementos finitos es nodalmente exacta cuando se utilizan ciertos espacios de aproximación de dimensión finita engendrados por splines generalizados. También se desarrolla el concepto de acción equivalente como generalización del de acción nodal equivalente. Finalmente se ilustra la aplicación de la metodología desarrollada, basada en la interpretación matricial citada, con ejemplos de splines en el campo de los gráficos, en el análisis de vigas continuas sobre fundación elástica, sometidas a flexión y tracción o compresión y en problemas dinámicos

Gold Functionalized Supported Ionic Liquids Catalyst for CO Oxidation.

The present study tries to give an insight to the combination of the homogeneous and heterogeneous catalytic properties in a new class of materials. Well dispersed gold nanoparticles on an ionic liquid layer supported on a mineral carrier have been prepared. This work is concentrated on the characterizations and understanding of the interactions between all the components of the catalytic system. The application of the materials in the reaction of oxidation of carbon monoxide shows rather unexpected results¿a good catalytic activity completely independent of the temperature.L. Bobadilla acknowledges Junta de Andalucía (Project PDG-TEP01965). S. Ivanova and A. Penkova acknowledge MEC for their contracts Ramon y Cajal and Juan de la Cierva.Peer Reviewe

Ultimate capacity of rectangular concrete-filled steel tubular columns under unequal load eccentricities

The paper describes 36 experimental tests conducted on rectangular and square tubular columns filled with normal and high strength concrete and subjected to a non-constant bending moment distribution with respect to the weak axis. The test parameters were the nominal strength of concrete (30 and 90 MPa), the cross-section aspect ratio (square or rectangular), the thickness (4 or 5 mm) and the ratio of the top and bottom first order eccentricities e top/e bottom (1, 0.5, 0 and - 0.5). The ultimate load of each test was compared with the design loads from Eurocode 4, presenting unsafe results inside a 10% safety margin. The tests show that the use of high strength concrete is more useful for the cases of non-constant bending moment, whereas if the aim is to obtain a more ductile behavior the use of concrete-filled columns is more appealing in the cases of normal strength concrete with non-constant bending moments because, although they resist less axial force than the members with HSC, they obtain a softened post-peak behavior. © 2011 Elsevier Ltd.The authors wish to express their sincere gratitude to the Spanish Ministry of Education for the help provided through projects BIA2005_255 and BIA2009_9411, and to the European Community for FEDER funds.Hernández Figueirido, D.; Romero, ML.; Bonet Senach, JL.; Montalva Subirats, JM. (2012). Ultimate capacity of rectangular concrete-filled steel tubular columns under unequal load eccentricities. Journal of Constructional Steel Research. 68(1):107-117. https://doi.org/10.1016/j.jcsr.2011.07.014S10711768

Symmetry-based computational search for novel binary and ternary 2D materials

We present a symmetry-based exhaustive approach to explore the structural and compositional richness of two-dimensional materials. We use a ``combinatorial engine'' that constructs potential compounds by occupying all possible Wyckoff positions for a certain space group with combinations of chemical elements. These combinations are restricted by imposing charge neutrality and the Pauling test for electronegativities. The structures are then pre-optimized with a specially crafted universal neural-network force-field, before a final step of geometry optimization using density-functional theory is performed. In this way we unveil an unprecedented variety of two-dimensional materials, covering the whole periodic table in more than 30 different stoichiometries of form A$_n$B$_m$ or A$_n$B$_m$C$_k$. Among the found structures we find examples that can be built by decorating nearly all Platonic and Archimedean tesselations as well as their dual Laves or Catalan tilings. We also obtain a rich, and unexpected, polymorphism for some specific compounds. We further accelerate the exploration of the chemical space of two-dimensional materials by employing machine-learning-accelerated prototype search, based on the structural types discovered in the exhaustive search. In total, we obtain around 6500 compounds, not present in previous available databases of 2D materials, with an energy of less than 250~meV/atom above the convex hull of thermodynamic stability

Systematic review of the nature of nursing care described by using the Caring Behaviours Inventory

Aim To describe the nature of care received by patients measured through the Caring Behaviours Inventory. Background Professional nursing practice combines two dimensions of caring: instrumental care and expressive care. Instrumental care focuses on physical health needs, in terms of efficiency and employs interventions based on evidence. Expressive care is patient‐centred and based on the interpersonal relationship. It requires caring attitudes that include respect, kindness, sensitivity and patience. The Caring Behaviours Inventory is a tool designed to assess the care expressed through the behaviours nurses perform, contextualised within the Jean Watson's Theory of Human Caring. Methods A systematic review following PRISMA recommendations. Scopus, PubMed and CINAHL databases were consulted using the keywords “Caring Behaviours Inventory” AND “Nursing”. The Joanna Briggs Institute tool was used for the quality appraisal. A conceptual analysis and a thematic synthesis were performed for data extraction. Results 11 articles were selected. Three categories were identified: nature of caring, congruence between perceived care by patients and nurses, and factors associated with the expression of care. Discussion An emphasis on care of an instrumental nature was identified. The perception of patients differs from that of nurses, patients perceive a lower level of expressive caring than the one nurses believe to deliver. Caring behaviours are affected by the working environment, nurses' emotional intelligence and coping skills, and socio‐demographic characteristics. Conclusion This paper described the findings of previous research regarding the nature of care that is transmitted and received in clinical practice. Results highlight an emphasis on the instrumental aspect of the nursing care according to the patients' perception. Relevance to clinical practice Findings summarised in this review could contribute to a better understanding of the nursing care. Results reported in this paper could also help to improve the quality of care delivered by nurses as well as patient‐centeredness

Early postoperative complications of transvaginal access in minimally invasive sigmoid colon procedures

Objectives: The aim of the study was to evaluate early (the first 30 days) postoperative complications after transvaginal resection of the sigmoid colon. Material and Methods: A total of 23 laparoscopy-assisted transvaginal resections of the sigmoid colon and 1 NOTES transvaginal sigmoid resection were performed in the course of 3 years. Postoperative complications were recorded in a prospective manner. Results: In the group of 24 patients operated on using the transvaginal approach, 6 (25%) complications were recorded, including 3 urinary tract infections, 2 vaginal bleedings, and 1 abdominal trocar site hernia. Conclusion: Early postoperative complication rate after transvaginal resection of the sigmoid colon is relatively low and the clinical complications are not severe

Design and manufacture of a customised temporomandibular prosthesis

In this work, design, manufacture and surgical success of a personalised temporomandibular prosthesis is featured. A fused deposition modelling technique and Die forging process constitute the methodology used in a patient who had an amputation in the upper third branch of the mandible, without considering the joint capsule. The implant was designed using a processed resection image of a computational tomography and using the methodology of Özkaya and Nordin. The jaw operating conditions were simulated by the finite element method (FEM). The main considered factors were the morphological geometry of the patient, implant fixation in the first third of the branch, implant fixation on the chin, dental post for placement of the teeth, and the form of the sub-lingual fossa weight optimisation. Special consideration was to preserve the patients facial aesthetics.Peer Reviewe