Search results for "CHANNEL"
showing 10 items of 1643 documents
New Stage–Discharge Relationship for Triangular Broad-Crested Weirs
2022
Simple hydraulic structures, such as weirs, allow measuring flow discharge by using the upstream flow depth and a stage–discharge relationship. In this relationship, a discharge coefficient is introduced to correct all the effects neglected in the derivation (viscosity, surface tension, velocity head in the approach channel, flow turbulence, non-uniform velocity profile, and streamline curvature due to weir contraction). In this paper, the dimensional analysis and the incomplete self-similarity theory are used to investigate the outflow process of triangular broad-crested weirs, characterized by different values of the ratio between crest height p and channel width B, and to theoretic…
Comment on "Measuring the flow resistance of submerged grass"
2004
In this short note, the experimental data of Wilson and Horritt (2002.Hydrological Processes16: 2589–2598), jointlywith the measurements by Kouwenet al. (1969.Journal of Irrigation and Drainage Division, ASCE95: 329–342)and by Raffaelliet al. (2002 InProceedings XXVIII Convegno di Idraulica e Costruzioni Idrauliche, Cosenza, Italy;223–230), arefirstly used to test Kouwen’s approach. All experimental data are then used to calibrate aflow resistanceequation that was theoretically deduced by dimensional analysis and self-similarity theory
How is social capital formed across the digital-physical servicescape?
2022
This study examines how consumers create social capital in interactions with other customers and service personnel while shopping in retail stores that consist of both physical and digital locations. We draw on servicescape literature to explore the role of social capital in determining the social realm in digital-physical servicescapes using data from focus group discussions. We demonstrate how customers utilize both the digital and physical servicescapes in a convergent manner to form the social realm of the servicescape with the other people in service encounters. The implications provide guidelines on how the integration of digital and physical channels facilitates trust, human contact,…
SingleChannelNet : A model for automatic sleep stage classification with raw single-channel EEG
2022
In diagnosing sleep disorders, sleep stage classification is a very essential yet time-consuming process. Various existing state-of-the-art approaches rely on hand-crafted features and multi-modality polysomnography (PSG) data, where prior knowledge is compulsory and high computation cost can be expected. Besides, it is a big challenge to handle the task with raw single-channel electroencephalogram (EEG). To overcome these shortcomings, this paper proposes an end-to-end framework with a deep neural network, namely SingleChannelNet, for automatic sleep stage classification based on raw single-channel EEG. The proposed model utilizes a 90s epoch as the textual input and employs two multi-conv…
Optical hybrid nanocomposite sensors for selective explosive detection
2022
Durant l'última dècada, la detecció d'artefactes explosius improvisats (IEDs) tant en l'àmbit militar com civil s'ha convertit en una prioritat estratègica en la seguretat nacional a causa de la creixent amenaça terrorista. Encara que les tècniques convencionals, com la cromatografia de gasos acoblada a espectrometria de masses o la difracció de raigs X mostren notables avantatges degut a la seua elevada sensibilitat i selectivitat, una gran part d’aquestes presenten inconvenients, com per exemple processos de mesura lents, instrumentació cara, complexa i voluminosa, que limiten el mostreig en continu i en temps real. Per aquesta raó, existeix una recerca constant per trobar una plataforma …
A Channel-Aware Adaptive Modem for Underwater Acoustic Communications
2021
Acoustic underwater channels are very challenging, because of limited bandwidth, long propagation delays, extended multipath, severe attenuation, rapid time variation and large Doppler shifts. A plethora of underwater communication techniques have been developed for dealing with such a complexity, mostly tailoring specific applications scenarios which can not be considered as one-size-fits-all solutions. Indeed, the design of environment-specific solutions is especially critical for modulations with high spectral efficiency, which are very sensitive to channel characteristics. In this paper, we design and implement a software-defined modem able to dynamically estimate the acoustic channel c…
Modelling flow and heat transfer in spacer-filled membrane distillation channels using open source CFD code
2013
Abstract A good understanding of the details of hydrodynamic and heat transport conditions and their impact on temperature polarisation and pressure drops is essential for optimum design of membrane distillation (MD) modules. To this end, the present work reports on initial progress in the development of a tool for 3D simulation of spacer-filled MD channels based on the open source CFD code library OpenFOAM. The paper discusses a number of modelling and implementation aspects including model geometry and computational domain, choice of boundary conditions, and discretisation schemes. The results pertaining to the effect of three different spacer types on the fluid dynamics and heat transfer…
Friction and Heat Transfer in Membrane Distillation Channels: An Experimental Study on Conventional and Novel Spacers
2022
The results of an experimental investigation on pressure drop and heat transfer in spacer-filled plane channels, which are representative of Membrane Distillation units, are presented and discussed. Local and mean heat transfer coefficients were obtained by using Thermochromic Liquid Crystals and Digital Image Processing. The performances of a novel spacer geometry, consisting of spheres that are connected by cylindrical rods, and are hereafter named spheres spacers, were compared with those of more conventional woven and overlapped spacers at equal values of the Reynolds number Re (in the range ~150 to ~2500), the pitch-to-channel height ratio, the flow attack angle and the thermal boundar…
On the spatial configuration of scatterers for given delay-angle distributions
2014
Published version of an article in the journal: Engineering Letters. Also available from the publisher at: http://www.engineeringletters.com/issues_v22/issue_1/EL_22_1_05.pdf. Open access This paper investigates the distribution of scatterers located around the mobile station (MS) for given delay-angle distributions. The delay-angle distribution function represents the joint probability density function (PDF) of the time-ofarrival (TOA) and angle-of-arrival (AOA). Given such a joint PDF, we first derive a general expression for the distribution of the scatterers in both polar and Cartesian coordinates. We then analyze an important special case in which the TOA and the AOA follow the multipl…
Understanding the impact of digital on performing arts: a systematic literature review proposal
2023
Digital technologies have profoundly changed the cultural and creative industries. Due to the intrinsic characteristics of the performing arts sector, this digital transition has had a later impact on it. However, it has accelerated since the Covid-19 pandemic, forcing organizations to digitally transform themselves to keep in touch with their audience(s). Now that this crisis is over, many strategic and operational questions still remain unanswered. This research proposes a systematic literature review in order to establish the state of the art of the research on digitalization of the performing arts sector and to highlight the main research avenues to be explored.