143 research outputs found
Retodus Churcher & Iuliis & Kleindienst 2006, n. gen.
No full textGenus Retodus n. gen. TYPE SPECIES. — Ceratodus tuberculatus Tabaste, 1963. ETYMOLOGY. — From the Latin, rete, net; - odus, Latinised Greek -Óδούυς, toothlike, referring to a network of ridges on the occlusal surface of a tooth plate. DIAGNOSIS. — The same as Retodus tuberculatus n. comb. REMARKS The new lungfish tooth plate (ROM 47638) reported here preserves features unknown in the species previously known as Ceratodus tuberculatus and indicates that the species cannot be referred to an already described genus. Although insufficient material of the species is known to permit a phylogenetic analysis, it is apparent that it forms a distinct clade, and thus merits generic distinction as Retodus n. gen.Published as part of Churcher, Charles S., Iuliis, Gerardo De & Kleindienst, Maxine R., 2006, A new genus for the Dipnoan species Ceratodus tuberculatus Tabaste, 1963, pp. 635-647 in Geodiversitas 28 (4) on page 637, DOI: 10.5281/zenodo.465097
FIG. 3 in A new genus for the Dipnoan species Ceratodus tuberculatus Tabaste, 1963
No full textFIG. 3. — Diagram of generalised right upper dipnoan tooth plate (based on ROM 47628), showing dimensions and terminology, from Churcher & De Iuliis (2001: 309, fig. 3A).Published as part of Churcher, Charles S., Iuliis, Gerardo De & Kleindienst, Maxine R., 2006, A new genus for the Dipnoan species Ceratodus tuberculatus Tabaste, 1963, pp. 635-647 in Geodiversitas 28 (4) on page 642, DOI: 10.5281/zenodo.465097
Quantifying restoration time of power and telecommunication lifelines after earthquakes using Bayesian belief network model
No full textNatural and human-made disasters can disrupt infrastructures even if they are designed to be hazard resistant. While the occurrence of hazards can only be predicted to some extent, their impact can be managed by increasing the emergency response and reducing the vulnerability of infrastructure. In the context of risk management, the ability of infrastructure to withstand damage and re-establish their initial condition has recently gained prominence. Several resilience strategies have been investigated by numerous scholars to reduce disaster risk and evaluate the recovery time following disastrous events. A key parameter to quantify the seismic resilience of infrastructures is the Downtime (DT). Generally, DT assessment is challenging due to the parameters involved in the process. Such parameters are highly uncertain and therefore cannot be treated in a deterministic manner. This paper proposes a Bayesian Network (BN) probabilistic approach to evaluate the DT of selected infrastructure types following earthquakes. To demonstrate the applicability of the methodology, three scenarios are performed. Results show that the methodology is capable of providing good estimates of infrastructure DT despite the uncertainty of the parameters. The methodology can be used to effectively support decision-makers in managing and minimizing the impacts of earthquakes in immediate post-event applications as well as to promptly recover damaged infrastructure
Effectiveness analysis of a semiactive base isolation strategy using information from an early-warning network
No full textIn this paper the possibility to manage data transferred by a Seismic Early Warning network to protect from collapse Base Isolated strategic structural systems by using semiactive devices has been investigated. In particular, by estimating the frequency content of the incoming seismic signal recorded at the accelerometric stations using a Fast Fourier Transform (FFT) technique, a new approach is proposed to estimate the seismic demand of the structure to be protected in order to eventually modify its mechanical features by means of semiactive devices. The analysis concerns a Base Isolated benchmark system equipped with semiactive devices located at the isolation layer, capable of modifying both the stiffness and damping of the overall structural system.
The effectiveness of the proposed strategy has been tested on varying the “anticipation time”, namely the range of the time interval between the start of the seismic data elaboration by the recorded stations and the arrival of the seismic S-wave to the interested site, the added stiffness and damping resources, as well as by taking into account different seismic input signals.
The results highlight the practical feasibility of the proposed strategy as well as the critical role played by the considered parameters on the performance of both the isolation level and superstructure. This work has to be intended as a first contribution concerning the potentiality of the Early Warning applications in reducing the seismic risk in built environments
Environmental Impact of Electricity Generation Technologies: A Comparison between Conventional, Nuclear, and Renewable Technologies
No full textThe transformation of the energy sector, based on the development of low-carbon technologies, is essential to achieve climate neutrality. The Life Cycle Assessment (LCA) is a powerful methodology for assessing the environmental impact of energy technologies, which proves to be a useful tool for policy makers. The paper is a review of the main LCA studies of power generation systems performed over the past ten years aiming at comparing the energy technologies to identify those with the lowest impact on the environment, evaluated in terms of gCO2eq/kWh emissions. Screening criteria were established to include only studies of the highest qualitative significance. The authors decided to assign greater weight to emission values reported in more recent studies. For nuclear and renewable energy technologies, most of the emissions are related to the pre-operational phases. Notably, both nuclear and wind technologies, along with other renewable sources throughout their entire life cycle, exhibit significantly lower and less variable emissions compared with conventional gas- and coal-fired technologies
Control System-Oriented MIMO Over-the-Air Computing
No full textThis paper applies the MIMO over-the-air computation (MIMO-AirComp) technique to compute the control signal of a distributed control system, including state estimation. The control-based target function is expressed as a nomographic function and efficiently computed through the wireless channel with suitable function decomposition. The proposed scheme leverages local pre-processing at the individual sensor, aggregation through the multiple access channel, and post-processing at the controller to compute the control-oriented nomographic function. We analyze the performance of our proposed scheme in terms of the time delay and computation error compared to a state-of-the-art MIMO time-division multiple access scheme by means of Monte Carlo simulations. Numerical results indicate that the proposed scheme considerably improves control performance, particularly in noisy networks that rely on a large number of wireless sensors, with low complexity for resource-constrained scenarios
FIG. 2 in A new genus for the Dipnoan species Ceratodus tuberculatus Tabaste, 1963
No full textFIG. 2. — Map of North Africa showing sites from which Ceratodus africanus (Haug, 1905), C. humei (Priem, 1914), and Retodus tuberculatus (Tabaste, 1963) n. comb. have been recovered, with inset maps of the oases of Kharga and Dakhleh (A, after Vivian 1990) and the Djoua Depression (B, after Foureau 1904). R. tuberculatus n. comb. was first described from Erg Iller and Rouaix (C), west of the Hoggar Mountains (Ahoggar or Hoggar Massif), and from Mt. Igdaman, south of the Hoggar Mountains in Niger (Tabaste 1963). National borders as dashed lines. Escarpments in A and B hatchured, dune areas in B stippled, Ain Umm Dabadib indicated by ●, Retodus tuberculatus n. comb. recovery sites indicated by □ in A, Ceratodus humei sites by ■ in A, and C. africanus sites by ■ in B, and trig points by ▲ with heights in metres. In A roads and the River Nile are shown as solid lines. In B, Bordj Omar Driss (= Fort Flatters = Timassânine) lies near ▲ 368. Information on Ceratodus sites in A after Churcher & De Iuliis (2001).Published as part of Churcher, Charles S., Iuliis, Gerardo De & Kleindienst, Maxine R., 2006, A new genus for the Dipnoan species Ceratodus tuberculatus Tabaste, 1963, pp. 635-647 in Geodiversitas 28 (4) on page 641, DOI: 10.5281/zenodo.465097
A PASSIVE ROBUST CONTROL STRATEGY FOR REINFORCED CONCRETE STRUCTURES: BASE ISOLATION AND TUNED MASS DAMPING
No full textCharacterization of a novel copper amine oxidase activity from rat liver mitochondria matrix
No full textTechno-economic feasibility of photovoltaic, BESS, diesel and hybrid electrification for off-grid rural systems in Algeria
No full textThe paper presents three case studies located in the Algerian localities of Afra, Tinelkoune and M'Guiden. Currently, the energy demands of the users and the ancillary services of microgrids are met by internal combustion engines powered by diesel. The authors propose an hybridization of the current energy system with photovoltaic panels and an electric battery for energy storage system. For the optimal choice of the size of the photovoltaic and the storage system, the capabilities of the technologies which would allow the lowest consumption of fossil fuels and the lowest cost for the entire energy system were considered. The results show the hourly behavior of the system throughout the year (two exemplary weeks of the winter and summer regime are shown for each of the three case studies). Furthermore, an economic analysis is conducted in order to identify the payback time of the investment to be made. Finally, a sensitivity analysis on diesel prices is conducted in order to show the variation of the economic assessments made
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