Universidad de Almería
  • Almería, Almeria, Spain
Recent publications
ABSTRACT The paramo, plays an important role in our ecosystems as They balance the water resources and can retain substantial quantities of carbon. This research was carried out in the province of Tungurahua, specifically the Quero district. The aim is to develop a classification of the land use land cover (LULC) in the paramo using satellite imagery using several classifiers and determine which one obtains the best performance, for which three different approaches were applied: Pixel-Based Image Analysis (PBIA), Geographic Object-Based Image Analysis (GEOBIA), and a Deep Neural Network (DNN). Various parameters were used, such as the Normalized Difference Vegetation Index (NDVI), the Bare Soil Index (BSI), texture, altitude, and slope. Seven classes were used: paramo, pasture, crops, herbaceous vegetation, urban, shrubrainland, and forestry plantations. The data was obtained with the help of onsite technical experts, using geo-referencing and reference maps. Among the models used the highest-ranked was DNN with an overall precision of 87.43%, while for the paramo class specifically, GEOBIA reached a precision of 95%.
With the development of new technologies, some concepts become relevant in the economic area, as is the case with cryptocurrencies, in general, or Bitcoin and Ethereum, in particular. Due to the impact of these tools, a detailed bibliometric study that allows us to obtain all information about cryptocurrencies must be conducted. This study will help scientific production by specifying the development and lines of related research that have been followed and are currently being followed. We have used Tableau, R (Bibliometrix R Package), and VOSviewer software to analyze the information. These have been combined to create and review unified metadata from the Web of Science (WoS) and Scopus databases. The bibliometric analysis shows 771 articles on the WoS database and 648 articles on Scopus published between 2010 and early 2019. They present the most relevant articles, research areas, countries, institutions, authors, journals, and trends during the last few years. In conclusion, the number of publications has grown in the last 3 years. The analysis shows the evolution of blockchain technology used in this type of cryptocurrency. The review of this period marks a possible end to the historical part of cryptocurrencies, thereby opening the current topic to its multiple applications.
Background The Circular Economy system can improve the product cycle and changes the system and mentality, both for production and the consumer and has become a significant alternative to the classic economic model. The retail sector has also started to advance along these lines. Following an analysis of the state of the art of the Circular Economy and retailing, using bibliometric techniques, our research focuses on understanding if the relationship between circularity and retailing can help us determine a business’ survivability and resilience. To this end, data pertaining to 658 commercial premises from four cities were studied over a period of 11 years. A Deep Learning technique is applied using Long Short-Term Memory to determine if there is a relationship between the resistance of the selected commercial premises, their status in previous periods of time, the type of business activity, and their classification in the Circular Economy plane. Results The system predicts, on the set of tests, with a 93.17% accuracy, the survival of a commercial premises based on the activity, and circularity information before 2012. The results of the training also show very significant precision values of the order of 94.15% with data from the post-depression period. Conclusions The results show that businesses with activities related to the Circular Economy are more likely to survive over extended periods of time.
Background This article aims to analyse the scientific production related to the impact worldwide of recreational and sports tourism on the conservation and management of coast and marine green infrastructures. To this end, the research focuses on two of the ecosystems, where this type of tourism exerts pressure on a global scale: seagrass meadows and coral reefs. Based on Scopus and WoS databases, different levels of analysis have been carried through the application of bibliometrics to identify the most prevalent topics and future research trends. Results The main results are summarised as follows. On the one hand, many publications in the scientific sector analyse how tourism and recreational activity affect specific marine ecosystems, especially coral reefs. On the other hand, the phenomenon of Global Change and the social and environmental effects on marine ecosystems with significant tourism potential have been identified as one of the most studied research topics. Finally, emerging research trends have been identified, including environmental monitoring and tracking programs aimed at controlling tourism, aspects related to the participation of the population and local tourism sectors, and the role of ecotourism in marine protected areas. Conclusions In conclusion, a greater commitment from the public administration and a greater social awareness of the ecosystem services it generates is needed. If the species and the natural environment are not conserved and protected, the tourist attractiveness of these areas would be lost and, ultimately, the tourism of the area would change, with the consequent loss of well-being for the whole community.
The application of a fair tariff for electricity pricing is aimed at controlling demand and promoting sustainability by motivating homeowners to use household appliances as well as heating and cooling systems that offer increased energy efficiency. It is possible to structure the price levels such that customers (typically those who have increased demands for electricity) are encouraged to lower their overall demand. The reorganisation of electrical subsidies within the residential sector has considerable importance for the country’s economy as well as for more effective management of the consumption of electricity and the resulting effects on the environment, which lays the foundation for more sustainable development. In the current research, data from 260,000 regular customers paying standard electricity tariffs were gathered and the energy usage of in excess of 1,000 energy-subsidised District Electricity Distribution Company (IDECO) members of staff was recorded over a period of two years (2017 and 2018). A comparison was made between the two aforementioned groups to investigate the outcomes of energy subsidies on energy usage as well as consumption patterns within the residential sector. The results of the analysis indicated that on average, normal homeowners used approximately 297 kWh/month, whereas customers whose electricity was subsidised consumed approximately 615 kWh/month. In both winter and summer, there was an increase in the amount of energy consumed, particularly among those receiving subsidies, as the demand for heating and cooling was raised. The application of electricity tariffs (with no subsidisation) provides a means of controlling the demand profile that is particularly effective. The structure of tariffs can motivate customers (typically those electricity consumption levels are high) to lower their overall consumption in addition to peak demand (which has the consequence of limiting the strain on the grid and power stations) by requiring them to pay for electricity at maximum prices.
This research aimed to evaluate the thermal performance of rooftop PV as a shading element on uninsulated roof-related HVAC energy consumption of buildings in a moderate dry–warm climate zone. A transient-state 3D distributed thermal model was developed of the PV-added rooftop components. Photovoltaic (PV) solar rooftops as shading devices were constructed using Integrated Environmental Solution-Virtual Environment Software to predict the reduction and increase in heating and cooling loads connected with the roof floor each month. The impact of rooftop PV systems on a building’s roof-related energy burden was quantified about a low-rise residential building in a moderate dry–warm climate zone represented by the city of Amman in Jordan. The results indicated that PV roof structure reduced heat gain by 10.87% during the summer and increased heat loss by 3.8% during the winter. In the summer season, the electricity demand for indoor cooling declined, but the demand for indoor heating increased slightly. The investigation focused on a middle-income home in Jordan’s capital, Amman. The limitations imposed by building rooftops on the use of PV were also investigated in this research and the findings validate the importance of providing environmental authorities, the construction industry, and ordinary individuals with important guidelines on the use of renewable energy to heat and cool buildings. Consequently, this analysis enhances awareness of a building’s overall energy needs, which are crucial for the future design of sustainable buildings.
This work presents the thermodynamic and techno-economic assessment of a forward osmosis – multi-effect distillation (FO-MED) system able to improve the thermal performance of the MED seawater desalination process and reduce its environmental impact. Energy, exergy and techno-economic analyses have been carried out to identify the best boundary conditions that enhance the process efficiency and water cost, predicting the scale formation with the Ryznar index. Results show that using FO pretreatment in a 100 m³/d MED plant of 8 effects at 65 °C allows increasing the heating steam temperature up to 100 °C and the number of effects to 16 without increasing the risk of scaling. This results in 44 % reduction of the specific thermal energy consumption and 21 % decrease in the specific heat transfer area. The volume of saline water rejected to the sea is reduced 40 % and the water footprint 36 %. The exergy analysis reveals that the MED is the component with the highest exergy destruction. Finally, the levelized cost of water of the FO-MED is higher (7.6 $/m³) than the standalone MED process (4.6 $/m³). If high-performing and cost-effective membranes are used, the product cost could be reduced 33 % (5.1 $/m³).
Olive mill wastewater (OMW) resulting from the olive oil extraction process is usually disposed of in evaporation ponds where it concentrates generating a sludge that pollutes the ponds nearby area. In this study, four bio-treatments were applied for the in-situ bioremediation and valorization of OMW sludge: Landfarming, phytoremediation, composting and vermicomposting. In all cases, the OMW sludge was added with organic residues (mushroom compost, rabbit manure, and chicken manure). The bio-treatments were carried out in duplicate, inoculated and non-inoculated, to determine the effect of a specialized fungal consortium (Aspergillus ochraceus H2 and Scedosporium apiospermum H16) on the efficacy of the bio-treatments. The evaluation of chemical parameters, toxicity, and functional microbial biodiversity revealed that the four techniques depleted the toxicity and favored the stimulation of functional microbiota. Landfarming and phytoremediation allowed the decontamination and improvement of soils. Composting and vermicomposting also offered high-quality products of agronomic interest. Inoculation improved the bioremediation effectiveness. Biological treatments are effective for the safe recovery of contaminated OMW sludge into high-quality services and products.
Loquat is a subtropical pome fruit of high economic value, since it is the earliest spring fruit reaching the markets. Different agricultural techniques may advance loquat fruit ripening and increase therefore its crop value. Unfortunately, a technique of great interest in this regard such as preflowering deficit irrigation (DI) has been found to increase the incidence of a specific loquat physiopathy known as purple spot. In order to clarify the environmental and cultural factors involved in purple spot appearance, we have compared its incidence in three consecutive years, determining the physiological stage and the size of the fruit at which the physiopathy appears, the amount of damaged fruit growing in different sections of the canopy, and compared fruit size and mineral composition of pulp and skin of fruit in damaged and undamaged fruit. We also compared purple spot incidence among five irrigation treatments (full irrigation, preflowering DI, and three different combinations of preflowering plus preharvest DI) in order to select DI treatments that reduce purple spot incidence while maintaining the benefits of harvest advancement. Our results show that purple spot was first detected at color break, when fruit had almost reached its final diameter. Late and earlier purple spot appearance was very rare. Damaged fruits were only slightly larger than healthy fruit. Significant variations in the incidence of purple spot were found among experimental blocks and years, with a low incidence in 2008/09 and 2009/10, and much larger in 2010/11. In all years, early maturing fruit and fruit growing in the canopy sections receiving more sunlight (South oriented) were more damaged by purple spot. In addition, DI treatments advancing fruit ripening provoked a higher incidence of purple spot. In spite of this response, the irrigation treatments in which water stress was also imposed at preharvest reduced the damage suggesting that altering pulp/skin water status and fruit growth rate might reduce purple spot. Finally, potassium, magnesium and especially copper were in much higher concentration in damaged fruit, especially in the skin. Nitrogen and calcium seem not to play any role in this physiopathy despite early assumptions and commonly applied preharvest calcium treatments.
Mango (Mangifera indica L.) is one of the main tropical fruit crops worldwide. Although mostly grown in open fields, protected cultivation of mango has recently increased. Pollination in mango mainly occurs by flies (myophily) among which the group of eristaline hoverflies (Diptera: Syrphidae) stands out. Greenhouse studies were conducted on the pollination services provided by Eristalinus aeneus released at three densities in a protected mango orchard in southern Spain, during two consecutive seasons (2019 and 2020). Medium and high densities (30 and 45 individuals per square meter, respectively) led to higher number of floral visits to the middle and apical portions of the inflorescences where hermaphrodite flowers are more common, which resulted in more pollen grains being transferred to the stigma of fertile flowers. Medium and high densities of E. aeneus increased yields and improved fruit quality compared to low density (15 individuals per square meter), no insect release, and conventional pollination management using bumblebees. Yield enhancement achieved by using hoverflies as pollinating agents at medium and high densities implies an economic gain for farmers ranging from 16% to 29% in 2019 and from 212% to 456% in 2020. Therefore, our results suggest that medium and high densities of E. aeneus are profitable pollination solutions for mango cultivated under greenhouses.
Let $X$ and $Y$ be compact subsets of $\mathbb{R}$ with at least two points. For $p\geq 1$, let $\AC^p(X)$ be the space of all absolutely continuous complex-valued functions $f$ on $X$ such that $f'\in L^{p}(X)$, with the norm $\left\|f\right\|_{\Sigma}=\left\|f\right\|_\infty+\|f'\|_p$. We describe the topological reflexive closure of the set of linear isometries from $\AC^p(X)$ onto $\AC^p(Y)$. Using this description, we prove that such a set is algebraically reflexive and 2-algebraically reflexive. Moreover, as another application, it is shown that the sets of isometric reflections and generalized bi-circular projections of $\AC^p(X)$ are topologically reflexive and 2-topologically reflexive.
Over the last decades, algorithms have been developed for checking copositivity of a matrix. Methods are based on several principles, such as spatial branch and bound, transformation to Mixed Integer Programming, implicit enumeration of KKT points or face-based search. Our research question focuses on exploiting the mathematical properties of the relative interior minima of the standard quadratic program (StQP) and monotonicity. We derive several theoretical properties related to convexity and monotonicity of the standard quadratic function over faces of the standard simplex. We illustrate with numerical instances up to 28 dimensions the use of monotonicity in face-based algorithms. The question is what traversal through the face graph of the standard simplex is more appropriate for which matrix instance; top down or bottom up approaches. This depends on the level of the face graph where the minimum of StQP can be found, which is related to the density of the so-called convexity graph.
The estimation of leaf wetness duration (LWD) is important for crop disease monitoring and early warning, because LWD provides the necessary conditions for pathogen infection. Crop canopy condensation caused by high humidity in greenhouses is one of the main causes of LWD formation, and measuring LWD in greenhouses is difficult. A simulation model based on agricultural meteorological parameters is typically used to replace field measurements. This study was conducted in a Chinese solar greenhouse. A 2D transient model based on computational fluid dynamics (CFD) was used to estimate the distribution of cucumber leaf condensation in a solar greenhouse during early summer nights in Beijing. The LWD was estimated by considering the duration of the simulated leaf condensation at each point and simulating the dehumidification effect under ventilation conditions. The visual observations of leaf condensation were compared with the simulation results from May 31 to June 1 and from June 3 to June 4, 2021 (cloudy and clear days, respectively). The horizontal leaf condensation was observed first near the south roof, whereas the vertical canopy had a longer LWD at 1 m from the ground (average value of 8 h). LWD was estimated using relative humidity thresholds (RMSE of 1.944 h on cloudy days and RMSE of 0.5 h on clear days), and the good agreement between measurements and estimation indicated that the 2D CFD model combined with the relative humidity threshold method could be used to estimate the temporal and spatial distribution of canopy LWD.
In this paper, weighted backward shift operators Tw associated to a Schauder basis of a Banach space are considered. These operators are emblematic in the setting of linear chaos in topological vector spaces. In a constructive way, it is shown the existence of a dense linear subspace having maximal dimension, all of whose nonzero members are simultaneously Tw-hypercyclic for every w belonging to a sequence of admissible weights. Our proof does not use any general result about algebraic or topological genericity.
Williams Point is an iconic late Quaternary sedimentary sequence exposed at the southern margin of Madigan Gulf at Kati Thanda – Lake Eyre (KT-LE), Australia's largest lake. The ∼15 m high cliff outcrop includes 6 m of aeolian sediments, capping a ∼0.5 m beach/shoreline facies containing abundant Coxiella (aquatic gastropod) unconformably overlying 5–6 m of fluvio-lacustrine facies. The base of the outcrop and the playa floor comprises shallow and deeper water laminated lacustrine sediments. We re-examine the stratigraphic sequence using detailed excavations, micromorphological analysis and geochemical characterisation (X-ray fluorescence, X-ray diffraction, palaeoecology, stable isotope analysis of gypsum hydration water and biogenic carbonates, rare earth element analysis) and present a revised chronology using single-grain optically stimulated luminescence (OSL) within a Bayesian framework. Our new chronostratigraphic data generally supports previous interpretations for Williams Point, but crucially refines the timing of several of the key sedimentological units. The deeper-water lacustrine facies on the lake floor, unconformably overlying the Miocene Etadunna Formation, were deposited 206 ± 13 ka (232–169 ka, 95% credible interval; C.I.). A palaeoplaya, or oxidised shallow lake deposits, formed at 153 ± 11 ka (175–131 ka, 95% C.I.) and the uppermost shallow water lacustrine facies at the base of the cliff was deposited at 131 ± 9 ka (150–113 ka, 95% C.I.). An unconformity separates these sediments from the overlying fluvio-lacustrine phase, securely constrained (with eight OSL samples) to 86 ± 4 ka (95–78 ka, 95% C.I.). The isotopic composition of the palaeo-lake water (δ¹⁸O and δD), reconstructed from the hydration water of syndepositional gypsum formed in-situ in these fluvio-lacustrine sediments, indicates wetter conditions at 95–78 ka than at ca. 232–131 ka. Based on the provenance analysis these fluvio-lacustrine and lacustrine sediments were sourced from the northern catchments within the Lake Eyre basin but with an additional contribution from the northern Flinders Ranges. An erosional unconformity separates this sedimentary unit from the overlying Coxiella beach facies, which itself dates to 71 ± 4 ka (79–63 ka; 95% C.I.). This beach facies is interpreted to represent a regressional shoreline or near-shore deposit formed during Marine Isotope Stage [MIS] 4. This is the most reliable palaeolake level indicator in the sequence and indicates a maximum water depth of 12 m. The overlying Williams Point aeolian unit (WPAU) dates to 49 ± 4 ka (56–41 ka, 95% C.I.), slightly younger than previous estimates. The modelled age for WPAU overlaps with (and is within uncertainty of) the last KT-LE megalake phase, which reached +5 m AHD at 48 ± 2 ka. However, considering its elevation (−3 to +3 m AHD), the age of this gypsiferous aeolian unit demands that it accreted as KT-LE was entering a playa phase with lengthy periods of exposed lake floor. In turn, this means that the putative Genyornis newtoni (a megafaunal flightless bird) which laid its eggs in the gypsiferous dunes, went extinct during a time of hydrological transformation. These results bring fresh perspectives to a site that has held a heavy sway over previous views of the Quaternary history of Australia's arid zone.
Introduction Researchers display an interest in studying aspects like the mental health of high-performance athletes; the dark side of sport, or the earliest attempts to study the so-called dark triad of personality in both initiation and high-performance athletes. Therefore, the objective of this paper is to determine the possible existence and magnitude of negative psychological aspects within a population of competition sailors and from a probabilistic point of view, using Bayesian Network analysis. Methods The study was carried out on 235 semi-professional sailors of the 49er Class, aged between 16 and 52 years (M = 24.66; SD = 8.03). Results The results show the existence of a Negative Tetrad—formed by achievement burnout, anxiety due to concentration disruption, amotivation and importance given to error—as a probabilistic product of the psychological variables studied: motivation, anxiety, burnout and fear of error. Conclusion These results, supported by Bayesian networks, show holistically the influence of the social context on the psychological and emotional well-being of the athlete during competition at sea.
Offshore wind energy is widely regarded as one of the most credible sources for increasing renewable energy production towards a resilient and decarbonised energy supply. However, current expectations for the expansion of energy production from offshore wind may lead to significant environmental impacts. Assessing ecological risks to marine ecosystems from electricity production from wind is both timely and vital. It will support the adoption of management measures that minimize impacts and the environmental sustainability of the offshore wind energy sector.
This study aimed to analyze the relationship among different evaluative reactions of the intergroup attitudes and contact in Spanish adolescents evaluating different ethnic minorities and in immigrant-background adolescents evaluating Spanish youth. This study was based on psychosocial models of great impact in the study of intergroup relations such as the Stereotype Content Model and the Behaviors from Intergroup Affect and Stereotypes Map, and incorporated a new approach to the study of attitudes: psychological networks. In total, 1122 Spanish adolescents and 683 adolescents with an immigrant background (Moroccan, Romanian or Ecuadorian origin) participated in the study, aged from 12 to 19 years. They answered a questionnaire with measures of stereotype dimensions (morality, immorality, sociability and competence), emotions (positives and negative), behavioral tendencies (facilitation and harm) and contact (quantity and quality). The results show similar structural patterns in the six studied groups, with emotions acting as links between stereotypes and behavioral tendencies. Moreover, positive and negative stereotype dimensions appeared as independent dimensions that were part of different processes: sociability and morality, and competence to a lesser extent, were related to facilitation behaviors through positive emotions, while immorality was related to harm behaviors through negative emotions. This could indicate that, to achieve successful intergroup relations involving cooperation and the development of friendly relationships, it would be appropriate to intervene in parallel in these two pathways. Due to the centrality of positive emotions (and sociability and immorality) and, therefore, their capacity to affect the entire network, focusing interventions on these variables could be an appropriate strategy to achieve overall positive attitudes.
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2,369 members
Fco. Javier Medianero Soto
  • Department of Geography, History and Humanities
Blanca Maria Plaza
  • Department of Agronomy
Miguel Guzmán
  • Department of Agronomy
Jose Manuel Aguilar-Parra
  • Department of Psychology
Juan Sebastián Fernández Prados
  • Department of Geography, History and Humanities
Carretera de Sacramento s/n, 04120, Almería, Almeria, Spain