Improved construction of concrete viaducts with movable scaffolding systems in Spain

The current paper relates the state of the art of construction of viaducts with a movable scaffolding system (MSS). Two different procedures are introduced: the traditional sequence and the new sequence applied to some viaducts in Spain. The traditional sequence consists of two phases: first, concreting the bottom slab and webs, and then concreting the top slab of the deck. Once the first and second casting phases are completed, the total prestressing force is introduced. The new sequence consists of concreting a self-supporting core (i.e., the bottom slab, webs, and only a portion of the top slab). Once the self-supporting core has hardened, a partial prestressing force is introduced so that the scaffolding can be advanced to the next span; the central zone of the top slab is cast in a second phase. Both sequences are described here with their constructive peculiarities and issues.Peer ReviewedPostprint (author's final draft

Anomaly detection and virtual reality visualisation in supercomputers

Anomaly detection is the identification of events or observations that deviate from the expected behaviour of a given set of data. Its main application is the prediction of possible technical failures. In particular, anomaly detection on supercomputers is a difficult problem to solve due to the large scale of the systems and the large number of components. Most research works in this field employ machine learning methods and regression models in a supervised fashion, which implies the need for a large amount of labelled data to train such systems. This work proposes the use of autoencoder models, allowing the problem to be approached with semi-supervised learning techniques. Two different model training approaches are compared. The former is a model trained with data from all the nodes of a supercomputer. In the latter approach, observing significant differences between nodes, one model is trained for each node. The results are analysed by evaluating the positive and negative aspects of each approach. On the other hand, a replica of the Marconi 100 supercomputer is developed in a virtual reality environment that allows the data from each node to be visualised at the same time.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. We would like to thank “A way of making Europe” European Regional Development Fund (ERDF) and MCIN/AEI/10.13039/501100011033 for supporting this work under the MoDeaAS project (grant PID2019-104818RB-I00). Furthermore, we would like to thank the University of Skövde and to ASSAR Innovation Arena for their support to develop this work

A new paradigm: cloud agile manufacturing

Cloud Agile Manufacturing is a new paradigm proposed in this article. The main objective of Cloud Agile Manufacturing is to offer industrial production systems as a service. Thus users can access any functionality available in the cloud of manufacturing (process design, production, management, business integration, factories virtualization, etc.) without knowledge — or at least without having to be experts — in managing the required resources. The proposal takes advantage of many of the benefits that can offer technologies and models like: Business Process Management (BPM), Cloud Computing, Service Oriented Architectures (SOA) and Ontologies. To develop the proposal has been taken as a starting point the Semantic Industrial Machinery as a Service (SIMaaS) proposed in previous work. This proposal facilitates the effective integration of industrial machinery in a computing environment, offering it as a network service. The work also includes an analysis of the benefits and disadvantages of the proposal

Structural behavior of non-symmetrical steel cable-stayed bridges

Despite of the growing number of built examples, the analysis of non-symmetrical cable-stayed bridges has not received considerable attention from the researchers. In feet, the effects of the main design parameters in the structural behavior of these bridges are not addressed in detail in the literature. To fill this gap, this paper studies the structural response of a number of non-symmetrical cable-stayed bridges. With this aim, a parametric analysis is performed to evaluate the effect of each of the main design parameters (the ratio between the main and the back span length, the pylon, the deck and backstay stiflhesses, the pylon inclination, and the stay configuration) of this kind of bridges. Furthermore, the role of the geometrical nonlinearity and the steel consumption in stays are evaluated.Peer ReviewedPostprint (published version

Surface Solar Extremes in the Most Irradiated Region on Earth, Altiplano

Satellites have consistently pointed to the Altiplano of the Atacama Desert as the place on Earth where the world’s highest surface irradiance occurs. This region, near the Tropic of Capricorn, is characterized by its high elevation, prevalent cloudless conditions, and relatively low concentrations of ozone, aerosols, and precipitable water. Aimed at studying the variability of the surface solar irradiance and detecting atmospheric composition changes in the Altiplano, an atmospheric observatory was set up in 2016 at the northwestern border of the Chajnantor Plateau (5,148 m MSL, 22.95°S, 67.78°W, Chile). Here, we report on the first 5 years of measurements at this observatory that establish the Altiplano as the region that receives the highest-known irradiation on Earth and illuminate the unique features of surface solar extremes at high-altitude locations. We found that the global horizontal shortwave (SW) irradiance on the plateau is on average 308 W m−2 (equivalent to an annual irradiation of 2.7 MWh m−2 yr−1, the highest worldwide). We also found that forward scattering by broken clouds often leads to intense bursts of SW irradiance; a record of 2,177 W m−2 was measured, equivalent to the extraterrestrial SW irradiance expected at approximately 0.79 astronomical units (AU) from the Sun. These cloud-driven surface solar extremes occur on the Chajnantor Plateau at a frequency, intensity, and duration not previously seen anywhere in the world, making the site an ideal location for studying the response of photovoltaic (PV) power plants to periods of enhanced SW variability.</p

PDA self-register system for eating disorders: a study on acceptability and satisfaction

Self-monitoring techniques, such as the use of dietary registers, are considered to be central to cognitive-behavioral treatment of Eating Disorders (ED). This information allows the clinician to identify the triggers of the behaviors associated to ED as purges and/or binges, and the associated thoughts and emotions, helping to carry out a more accurate assessment. Traditionally these registers are made with paper and pencil mode, where the patient has to register every eating and the emotions/thoughts associated; but this system has some problems, as low portability, low adherence or methodological difficulties. The use of PDA for self-registers can help to solve these problems. The aim of this study is to study the levels of acceptability and satisfaction with PDAs self-register system specifically designed for assessment and treatment of ED. Samples of 30 subjects diagnosed with ED are receiving a PDA with software specifically designed for recording type and amount of food, emotions before and after eating and other behaviors. The participants are completing self-register daily during a week, and afterwards answer an acceptance and satisfaction questionnaire. This work is in progress at the moment. It is expected that the PDA system will show high levels of acceptance and satisfaction

Persistent extreme ultraviolet irradiance in Antarctica despite the ozone recovery onset

Attributable to the Montreal Protocol, the most successful environmental treaty ever, human-made ozone-depleting substances are declining and the stratospheric Antarctic ozone layer is recovering. However, the Antarctic ozone hole continues to occur every year, with the severity of ozone loss strongly modulated by meteorological conditions. In late November and early December 2020, we measured at the northern tip of the Antarctic Peninsula the highest ultraviolet (UV) irradiances recorded in the Antarctic continent in more than two decades.The support of INACH (RT_69-20 & RT_70-18), ANID (ANILLO ACT210046, FONDECYT 1191932 & 1221122, DFG190004 and REDES180158), CORFO (19BP-117358 & 18BPE-93920) is gratefully acknowledged

Evaluation of MODIS-derived estimates of the albedo over the Atacama Desert using ground-based spectral measurements

Surface albedo is an important forcing parameter that drives the radiative energy budget as it determines the fraction of the downwelling solar irradiance that the surface reflects. Here we report on ground-based measurements of the spectral albedo (350–2200 nm) carried out at 20 sites across a North–South transect of approximately 1300 km in the Atacama Desert, from latitude 18° S to latitude 30° S. These spectral measurements were used to evaluate remote sensing estimates of the albedo derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). We found that the relative mean bias error (RMBE) of MODIS-derived estimates was within ± 5% of ground-based measurements in most of the Atacama Desert (18–27° S). Although the correlation between MODIS-derived estimates and ground-based measurements remained relatively high (R= 0.94), RMBE values were slightly larger in the southernmost part of the desert (27–30° S). Both MODIS-derived data and ground-based measurements show that the albedo at some bright spots in the Atacama Desert may be high enough (up to 0.25 in visible range) for considerably boosting the performance of bifacial photovoltaic technologies (6–12%)

Black carbon in the Southern Andean snowpack

The Andean snowpack is an important source of water for many communities. As other snow-covered regions around the world, the Andes are sensitive to black carbon (BC) deposition from fossil fuel and biomass combustion. BC darkens the snow surface, reduces the albedo, and accelerates melting. Here, we report on measurements of the BC content conducted by using the meltwater filtration (MF) technique in snow samples collected across a transect of more than 2500 km from the mid-latitude Andes to the southern tip of South America. Addressing some of the key knowledge gaps regarding the effects of the BC deposition on the Andean snow, we identified BC-impacted areas, assessed the BC-related albedo reduction, and estimated the resulting snow losses. We found that BC concentrations in our samples generally ranged from 2 to 15 ng g-1, except for the nearly BC-free Patagonian Icefields and for the BC-impacted sites nearby Santiago (a metropolis of 6 million inhabitants). We estimate that the seasonal snowpack shrinking attributable to the BC deposition ranges from 4 mm water equivalent (w.e.) at relatively clean sites in Patagonia to 241 mm w.e. at heavily impacted sites close to Santiago. © 2022 The Author(s). Published by IOP Publishing Ltd