Building Ontologies at the Knowledge Level using the Ontology Design Environment

This paper discusses how ontologies can be specified at the knowledge level using the set of intermediate representations (Gómez-Pérez, Fernández & de Vicente 1996) proposed by METHONTOLOGY (Fernández, Gómez-Pérez & Juristo 1997; and Gómez-Pérez 1998). These intermediate representations bridge the gap between how people think about a domain and the languages in which ontologies are formalized. Thus, METHONTOLOGY enables experts and ontology makers unfamiliar with implementation environments to build ontologies from scratch. In this paper, we also present the ODE (Ontology Design Environment) as a software tool to specify ontologies at the knowledge level. ODE allows developers to specify their ontology by filling in tables and drawing graphs. Its multilingual generator module automatically translates the specification of the ontology into target languages

Risk of incident cardiovascular events amongst individuals with anxiety and depression:A prospective cohort study in the east London primary care database

Background It is unknown how risk of myocardial infarction and stroke differ for patients with and without anxiety or depression, and whether this risk can be explained by demographics, medication use, cardiovascular risk factors. The aim of this study is to quantify differences in risk of non-fatal MI or stroke among patients with anxiety or depression. Methods Prospective cohort study examining risk of incident MI and stroke between March 2005 and March 2015 for 524,952 patients aged 30 and over from the east London primary care database for patients with anxiety or depression. Results Amongst 21,811 individuals with depression at baseline, 1.2% had MI and 0.4% had stroke. Of 22,128 individuals with anxiety at baseline, 1.1% had MI and 0.3% had stroke. Depression was independently associated with both MI and stroke, whereas anxiety was associated with MI only before adjustment for cardiovascular risk factors. Antidepressant use increased risk for MI but not stroke. Mean age at first MI was lower in those with anxiety, while mean age at first stroke was lower in those with depression. Limitations The study was limited to patients currently registered in the database and thus we did not have any patients that died during the course of follow-up. Conclusions Patients with depression have increased risk of cardiovascular events. The finding of no increased cardiovascular risk in those with anxiety after adjusting for cardiovascular risk factors is of clinical importance and highlights that the adequate control of traditional risk factors is the cornerstone of cardiovascular disease prevention. Targeting management of classical cardiovascular risk factors and evaluating the risks of antidepressant prescribing should be prioritized.</p

Accelerated testing methods to analyse long term stability of a Phase Change Material under the combined effect of shear stress and thermal cycling

The long-term stability of a Phase Change Material (PCM) is a key point for its selection in energy storage devices. This work studies the suitability of a commercial paraffin wax in an active scraped surface heat exchanger for solar energy storage purposes. In these devices, the continuous scraping of inner walls during solidification removes PCM and increases the released heat. Hence, the PCM is affected by a high level of shear stress. In order to study a potential degradation of the paraffin, a novel accelerated procedure has been designed for obtaining samples with a different number of thermal and scraping cycles. The procedure allows to evaluate the effect of shear stresses, thermal cycles and their combined effects separately. Up to 3000 cycles have been generated, which accounts for around 8 years of continuous daily work in the heat exchanger. The measurements through Differential Scanning Calorimetry, rheometry and thermal conductivity analysis have shown that neither the thermal nor the scraping cycling have a significant impact on the paraffin thermo-physical properties. According to the findings reported in this work, paraffin wax RT44HC can be successfully used in scraped surface heat exchangers. It is expected that other commercial paraffins would be also suitable since most of them share the fact of being blends of alkanes and other hydrocarbons.The authors gratefully acknowledge to European Regional Development Fund and Ministerio de Ciencia e Innovación - Agencia Estatal de Investigación for the financial support of the project ALTES: “Active Latent Thermal Energy Storage”, Ref. PGC2018-100864-B-C21

Experimental performance of a novel scraped surface heat exchanger for latent energy storage for domestic hot water generation

In this work, a novel design of a real scale Scraped Surface Heat Exchanger (SSHE) for solar LTES has been developed and experimentally tested. The main issue in PCM heat exchangers is the growth of a solid layer at the heat transfer walls during the latent energy extraction/discharging, that lowers heat transfer. The removal of the solidified PCM through scraping increases the heat transfer rate with nearly constant heat flux. Those characteristics make it suitable for domestic hot water generation. Discharging tests have been performed in scraping and no scraping modes (SM and nSM). The heat release rate in SM has shown to be between two and three times higher than in nSM. Moreover, in SM there is a complete extraction of the available latent energy (11.9 MJ) in a short period, compared to nSM. Additionally, a performance comparison between the developed SSHE and those available in open literature has been done. The results of heat release density (4 kW/m2) and overall heat transfer coefficient (1000 W/m2K) have shown similar values, though the scraping mechanism, the rotational speed, the size and their energy capacity are different. The developed design is an appropriate technology to increase the efficiency in solar LTES.The authors gratefully acknowledge to European Regional Development Fund and Ministerio de Ciencia e Innovación - Agencia Estatal de Investigación for the financial support of the project ALTES: “Active Latent Thermal Energy Storage”, Ref. PGC2018-100864-B-C21. We are also grateful to the company Outheway for the technical support in the design and manufacturing of scraper rotative heat exchanger. The present publication was first presented at the 16th Conference on Sustainable Development of Energy, Water and Environment Systems SDEWES conference, Dubrovnik, Croatia, 10–15 October 2021

Template-controlled acidity and catalytic activity of ferrierite crystals

A synthesis strategy to tailor the acid sites location in ferrierite crystals has been developed. The zeolite catalysts were synthesised in fluoride medium using different combinations of organic structure directing agents (SDAs) in the absence of inorganic cations. Therefore, the negative charge associated to the incorporation of aluminium to the framework was compensated exclusively by the positive charge of the organic SDAs. In this way, Al sitting in the zeolite framework was driven by the specific location of the different SDA molecules within the zeolite void volume. Following this synthesis strategy, it has been found that the distribution of strongly acidic hydroxyl groups in the proton form of the zeolites obtained after removal of the organic templates was dependent on the combination of organic molecules used as SDAs. Moreover, the catalytic activity of the zeolites in m-xylene and 1-butene isomerisation increased as the relative population of strong Brönsted acid groups in sterically constrained sites inside the ferrierite cavity decreased.This work has been financially supported by the MICINN (project CTQ2006-06282).Peer reviewe

Experimental correlations on critical Reynolds numbers and friction factor in tubes with wire-coil inserts in laminar, transitional and low turbulent flow regimes

This paper analyses 23 circular helicoidal wire-coils with different geometric characteristics ranging from: dimensionless pitch p/d = [0.25–3.37], dimensionless thickness e/d = [0.071–0.286] and a Reynolds number interval from 50 to 8000. This interval widely includes the Reynolds number range in which rigid wire-coil inserts present better performance as passive enhancement technique for tubular heat exchanger applications Re = [200–2000]. Based on their hydraulic performance, the wire-coil inserts are categorized according to a new dimensionless parameter: the Transition Shape Parameter (TSP). A new set of correlations are obtained to predict the Fanning friction factor coefficient as a function of Reynolds number and geometrical characteristics of the insert within the three flow regimes: laminar, transitional and low turbulent. Additional correlations are proposed to estimate the critical Reynolds number at the beginning and ending of the transition region, which allows to select the most adequate friction factor correlation as a function of the operational Reynolds number for a heat exchanger design application. Finally, a comparative between the proposed and the published correlations in the open literature for laminar and turbulent regimes is presented. This brings to light the need and interest of having the suitable and reliable set of correlations presented in this paper to compute the friction coefficient covering all the wire-coil applicability range as an enhancement technique.The authors gratefully acknowledge the “Fundación Séneca” (Fundación Séneca: Project with Ref. 15297/PI/10) and the Spanish Ministry of Science (Project with Ref. ENE2011-28571-C02-01) for supporting this research

Validation of a new methodological approach for the selection of wire-coil inserts in thermal equipment

The use of wire-coils is especially relevant at low Reynolds numbers (below the critical number to turbulent flow in smooth tubes) according to its inherent positive features such as the advance of transition onset and, if they present suitable geometric characteristics, the establishment of an extended transitional flow in a critical Reynolds number interval [ReCL − ReCT ], with a predictable friction coefficient and Nusselt number. This paper presents the experimental validation of a new methodology based on the evaluation of a non-dimensional geometry-based parameter: the TSP (Transition Shape Parameter) that allows to predict the friction coefficient evolution with wire-coil inserts and enables to compute the extension of the transitional flow region. The close relationship between hydraulic and thermal performance of wire-coil inserts makes this methodology a valuable tool for selecting the most appropriate wire-coil geometry for a given tubular heat exchanger. It is observed that to promote an increase in heat transfer, the value of the ReCL of the wire coil must be less than the operating Reynolds number range of the equipment. Thus, the ReCL − ReCT interval of the insert should fall into this range. In order to validate the methodological approach, an application to harp-type solar thermal collectors with typical Reynolds number range [40–6000] is presented. Four representative wire-coils, with a wide geometrical range characterized by TSP values of 759, 196, 35.3 and 3.1 (exhibiting significant differentiated behaviours in their friction factor curves and critical Reynolds numbers) were inserted inside the risers of a modified solar collector and experimentally tested at laboratory conditions. Static temperature at different locations at the absorber plate, and pressure drop were measured to obtain friction factor and Nusselt number inside riser covering the laminar, transitional and low-turbulent regions. For a general application with friction factor constraints the most suitable wire-coil geometry is the TSPW02 = 196 with a range of critical Reynolds number of ReCL = 663 and ReCT = 2286 and Nuw02/Nus = 2.21 for Re = [300 − 3000] with f w02/fs = 3, 82. However, for the case study presented (a harp-type solar collector) it is feasible to insert the third wire-coil geometry TSPW03 = 35.3 due to its early transition, with a range of critical Reynolds number of ReCL = 364 and ReCT = 2324, and Nuw/Nus = 1.35 for Re = 300 with a high friction factor augmentation f w03/fs = 18.84. This geometry also promotes the highest absorber temperature reduction. The greatest temperature reduction is observed in the range of Reynolds numbers [700–2000], reaching approximately 6 ◦C, which represents approximately 15 %The authors gratefully acknowledge to European Regional Development Fund and Ministerio de Ciencia e Innovación - Agencia Estatal de Investigación for the financial support of the project ALTES: “Active Latent Thermal Energy Storage”, Ref. PGC2018-100864-B-C21

The role of insert devices on enhancing heat transfer in a flat-plate solar water collector

This work presents a comparative experimental study of heat transfer enhancement in a flat-plate solar water collector using insert devices. Three wire-coils and three twisted-tapes were selected with representative geometrical characteristics typically employed in industrial applications. Isothermal pressure drop tests were carried out to obtain the fully-developed Fanning friction factor for a range of Reynolds numbers Re = [80–9000]. The increase in friction factor in comparison to smooth tube was computed for all the devices. Depending on Reynolds number and insert geometry fi/fs values ranged from 1.3 to 79.8. Furthermore, detailed temperature profiles were obtained for different sections along the absorber plate and the risers for five different mass flow rates covering the Reynolds range from [400–2500]. The increase of the inner heat transfer coefficient by the inserts caused an important decrease of the absorber temperature. At increasing mass flow rates (from Re ≈ 1000), all the inserts showed a very similar thermal performance which make them suitable for inserting within harp-type solar collectors, where pressure drop is not a constraint. The best inserts TT03, WC01 and WC02 gave at Re ≈ 1500 maximum absorber temperature decreases (insert vs smooth tube) of 5.05 °C, 5.40 °C and 5.34 °C. In serpentine-type solar collectors, due to pressure drop constraints, the wire coil WC01 with a moderate pitch to wire-diameter ratio (p/d = 1.5 and e/d = 0.07), is the best specimen to insert. WC01 presents a moderate pressure drop increase (fi/fs = 2.8 at Re ≈ 1000), an early promotion of turbulent flow (at Re ≈ 700), and a significant reduction of the absorber temperature (decreasing 4.84 °C vs smooth tube at Re ≈ 1000).The authors gratefully acknowledge the “Agencia de Ciencia y Tecnología de la Región de Murcia” (Fundación Séneca: Project with Ref. 15297/PI/10) and the Spanish Ministry of Science (Project with Ref. ENE2011-28571-C02-01) for supporting this research

Objetivos y medios idóneos relativos a la dependencia funcional

Las situaciones de dependencia funcional extraordinaria entrañan la demanda de apoyos supletorios, y es un objetivo propio de la política social cubrir el riesgo de carencia de aquéllos. También tienen esa condición la prevención y la rehabilitación, pero son menos valorados. Por otra parte, en España, los objetivos propios sufren la competencia de los colaterales, especialmente el logro de retornos sociales y económicos mediante la atención a la dependencia. En cuanto a los medios de atención, también en España, la presión de proveedores mercantiles y de corporaciones profesionales está alterando la elección de aquéllos según criterios centrados en el interés de los usuarios. Ello ha tenido una manifestación muy ostensible en la reforma de la Ley de Dependencia llevada a cabo en 2012

Objetivos y medios idóneos relativos a la dependencia funcional

Las situaciones de dependencia funcional extraordinaria entrañan la demanda de apoyos supletorios, y es un objetivo propio de la política social cubrir el riesgo de carencia de aquéllos. También tienen esa condición la prevención y la rehabilitación, pero son menos valorados. Por otra parte, en España, los objetivos propios sufren la competencia de los colaterales, especialmente el logro de retornos sociales y económicos mediante la atención a la dependencia. En cuanto a los medios de atención, también en España, la presión de proveedores mercantiles y de corporaciones profesionales está alterando la elección de aquéllos según criterios centrados en el interés de los usuarios. Ello ha tenido una manifestación muy ostensible en la reforma de la Ley de Dependencia llevada a cabo en 2012