Search results for "102"
showing 10 items of 2892 documents
Performance Study of Twisted Darrieus Hydrokinetic Turbine With Novel Blade Design
2021
Abstract Twisted Darrieus water turbine is receiving growing attention for small-scale hydropower generation. Accordingly, the need for raised water energy conversion incentivizes researchers to focus on the blade shape optimization of twisted Darrieus turbine. In view of this, experimental analysis has been performed to appraise the efficiency of a spiral Darrieus water rotor in the present work. To better the performance parameters of the studied water rotor with twisted blades, three novel blade shapes, namely U-shaped blade, V-shaped blade, and W-shaped blade, have been numerically tested using a computational fluid dynamics three-dimensional numerical model. The maximum power coefficie…
Thermal response test analysis for U-pipe vertical borehole heat exchangers under groundwater flow conditions
2021
[EN] Conventional models used in the analysis of thermal response test data only consider conduction as heat transfer mechanism. In cases where presence of groundwater is detected, convection heat transmission plays an important role, so its influence must be determined in the calculation of the effective thermal conductivity, usually overestimated in these situations, increasing its value the higher the power injected and the time elapsed. In this work, based on the data collected in a borehole located at UPV (Valencia) in which have been carried out three thermal response tests with different characteristics, has been implemented a variation of the finite line source model introducing an …
Multi-Dimensional Acquisition, Representation, and Interaction of Cultural Heritage Tangible Assets
2018
The acquisition, digital representation and interaction of cultural heritage (CH) assets is of high interest for an accurate documentation of our cultural legacy. Detailed studies demand more information on the assets apart from the mere visual appearance or even shape of objects. In this regards, some research works can be found that combine shape with other kind of data, such as radiometric (e.g., IR, thermal radiation, etc.) or semantic information, leading to multi-Dimensional (mD) virtual objects. In this chapter, we review the state of the art of different techniques to deal with mD acquisition of CH tangible assets. We also discuss some representation (e.g., visual, sonic, etc.) and …
3-Phase grid-connected building integrated photovoltaic system with reactive power control capability
2020
Abstract Recently, a tendency in the growing of grid-connected building integrated photovoltaic (BIPV) systems has been noticed in most countries. Hence, high penetration of PV power into the system network can be observed in many points in the network. This may cause severe problems on the distribution network due to the intermittent nature of PV systems. As a feasible solution, the reactive power capability of voltage source inverter in PV systems can be employed rather than approaching expensive grid infrastructures in the distribution network. The purpose of this study is to implement a 3-phase grid-connected (BIPV) system with reactive power control to regulate the system voltage and i…
Multifarious pretreatment strategies for the lignocellulosic substrates for the generation of renewable and sustainable biofuels: A review
2020
Abstract Currently major part of the world’s energy requirements is fulfilled by fossil resources. Severe economic and environmental problems along with their limited resources are still a major issue. Long-term environmental and commercial concern has focussed into huge research in the past decades to replace fossil fuels with renewable sources of energy. The main focus of energy research is lignocellulosic substrates, which seems to be the best for energy application due to easily availability, cost-effective and environment favourable production process. Therefore, lignocellulosic materials provide economical, environmental and energetic benefits with an alternative to traditional or hig…
Analysing the effects of power swing on wind farms using instantaneous impedances
2020
Abstract Most of the grid disturbances happen due to the presence of faults and power swing. This article focuses on power swing in view of the amount of penetration of renewable energy resources especially the wind farms. There are two sections. First section approached power swing by deriving a mathematical expression which would be able to track the locus of impedance in time domain and subsequently analyze resistance and reactance simultaneously with respect to time. It used a grid comprising of generator, transmission line and load. The derived expression was compared with a power swing generated using RTDS model and the results were analyzed in R-X plane. Second section analyses the i…
“Not in Possession of Any Weltanschauung”: Otto Neugebauer’s Flight from Nazi Germany and His Search for Objectivity in Mathematics, in Reviewing, an…
2016
Two major factors have to be considered to account for Neugebauer’s “Weltanschauung”, in particular his apparent or real rejection of philosophical or political judgments. On the one hand, Neugebauer, as a mathematician and a historian, had to cope, with the double character of mathematics as a science in its continuity and universality, independent of time, and of mathematics as a characteristic and fundamental product of each individual culture. On the other hand emphasis has to be put on Neugebauer being torn between organizational work (institution building, reviewing, editing) and historical research. One has to consider the vicissitudes of Neugebauer’s long and eventful life, which wa…
Herodotus’ awareness of the Peloponnesian War
2020
AbstractThis article aims to discuss the relationship between Herodotus and Thucydides. New scholarly trends date the composition of Herodotus’Historiesto 413 BC, or even later, against high chronology of 431, and suggest Herodotus’ use of Thucydides’ narrative. Herodotus’ debt to Thucydides has been suggested by scholars either cautiously or boldly. This examination will show cases where Herodotus is alluding to events of the Peloponnesian War or even responding to Thucydides’ narrative. In fact, anachronisms, presentisms, and allusions to Thucydides’ text can be found throughout Herodotus’ narrative. We will explore the reasons for Herodotus’ engaging with the events of that War, conjectu…
Le soin aux chevaux à l’époque celtique : trousses de vétérinaires et attestation du fer à cheval
2016
Cette communication présente pour l’époque celtique, l’évolution des trousses d’instruments de médecine et une nouvelle preuve de l’usage du fer à cheval dès l’Antiquité. This paper presents, for the Celtic period, the evolution of the doctor’s bag and new proof of the use of the horseshoe as soon as this period.
Animality and Biblical Masculinities in Conflict: Moses and the Golden Calf (Exodus 32)
2020
The purpose of this article is to analyze the masculinity of the biblical figure Moses in relation to the golden calf in Exodus 32. The prophet has been used as a model of biblical masculinity based on criteria such as violence, persuasive ability, his relationship to women, and physical disability. However, no gender construction derived from his interaction with the animal idol has been considered. In the context of the intersection of “animal studies” and “masculinity studies,” this article proposes the conceptualization of a biblical “zoomasculinity” linked to the prophet. Cohabitation with the theriomorphic statue allows Moses to embody diverse alternative masculinities that culminate…