Media Configuration Research Articles

Solution‐Processed Perovskite Quantum Dot Quasi‐BIC Laser from Miniaturized Low‐Lateral‐Loss Cavity

AbstractLaser devices produced via solution‐processed perovskite quantum dots (QDs) offer broad spectral tunability as well as ease of fabrication. Utilizing quasi‐bound states in the continuum (quasi‐BIC) modes, solution‐processed QD laser devices have been demonstrated with a nanostructure coated in a thin‐film gain media configuration. However, light leakage through thin‐film guiding from the cavity side edges becomes more pronounced when shrinking the cavity size, posing challenges for the miniaturization of quasi‐BIC‐based lasers. Here, the fabrication of well‐defined patterns of QDs via a solution process allows them to take advantage of the pattern edges to reduce losses through the cavity edges. A single‐mode BIC laser is reported by using CsPbBr3 QDs with a narrow linewidth of ≈0.1 nm. Importantly, a miniaturized quasi‐BIC laser is realized with a device size as small as 10 × 10 µm2, making it the smallest among existing solution‐processed BIC lasers. This work provides a strategy for developing ultra‐compact BIC lasers via solution‐processed gain media.

Generation of structure light in probe absorption spectrum via microwave-driven Y-type atomic system

Behavior of structure light is investigated by monitoring probe absorption using a microwave-driven Y-type atomic media configuration. The system under consideration is driven by one of the control vortex beams as well as an extra non-vortex control beam to ensure electromagnetically induced transparency. The significant aspect in the generation of structured light is the azimuthal phase-dependent modification for probe absorption. Further intensity distribution for absorption spectra is examined for simultaneously evaluating both the control vortex beams. We also go through the radial distribution of intensity for various orbital angular momentum values. Different modes of structural beams may be distinguished using the suggested approach. Our research gives us a way for rapidly transferring vortex wavefronts from control field to probe absorption profile. This could be useful in quantum information processing.

Projecting Creative Processes: Art Films and Art Education in Post-war Britain

The relationship between film and art education has received little scholarly attention. This paper describes and discusses one instance in the long and multifaceted history of this relationship: the educational uses of nonfiction films about art and artists in post-Second World War Britain, known then invariably either as ‘films on art’ or ‘art films.’ As a new international genre (backed by UNESCO’s educational distribution schemes), it gained particular momentum in the UK with the Arts Council of Great Britain, a public body, set up after the war with a mission ‘to increase the accessibility of the fine arts.’ And one of the ways it did was via 16mm projection. Alongside building a substantial film library, in 1950 the Council, in collaboration with the British Film Institute (BFI), started a new mobile cinema scheme, the Art Film Tour, to directly engage with the nontheatrical cinema sector, especially its educational venues. By drawing on my research in the Arts Council Archive, I propose to adopt a ‘historical pragmatics’ perspective and to study the Art Film Tour’s media configuration as a dispositif (Kessler, 2018). In the 1950s, with an increasing number of art films dedicated to artists at work, art students encountered cinematic renderings of the creative process by renowned modern artists, such as Picasso, Henry Moore and Jackson Pollock. And therefore, I make a case for an inductive analysis of ‘showing making’ on screen and its implications within historicised art education contexts.

On the CO2 photocatalytic reduction over indium tin oxide (ITO) ultra-thin films in water vapor: Experimental and theoretical study

Artificial photosynthesis that converts CO2 and H2O into compounds with added value is a viable method for reducing atmospheric CO2 concentration. In this study, we investigated the photocatalytic activity of ultrathin indium tin oxide (ITO) films on rigid and flexible substrates for CO2 reduction in water vapor and batch and flow setups. To explain a viable reaction mechanism for the 2760 ± 10 % μmol.gcat-1.hr-1 production rate achieved in a continuous reaction system, several theoretical models were developed. According to DFT simulation results, oxygen vacancy might be regarded as the main reaction site for CO2 to CO conversion. Moreover, a viable reaction pathway leading to CH4 formation is proposed. The catalyst’s lower rate of CO2 reduction in the batch reactor as compared with the flow reactor was justified via surface affinity simulation. Our findings highlight the significance of the catalyst’s structural design and reaction media configuration for stability and high activity.

New UV-LED frontal flow photocatalytic reactor for VOCs treatment: Compactness, intensification and optimization studies

This study investigates and provides a solution for optimizing the photocatalytic treatment of toxic gases based on the use of TiO2 media deposited on luminous textiles. The target was the cyclohexane referent for the type A gas filtration tests. The photocatalytic supports were characterized by scanning electron microscopy. Then, the experiments conducted on a batch reactor showed that the TiO2-coated optical fiber media (in situ illumination configuration) performs better than conventional configuration (cellulosic TiO2 with external radiation ''UV lamp''. To take advantage of the new optical fiber media configuration, an intensification study was carried out by increasing the amount of TiO2 in the media and UV intensities of LED. Increasing these two parameters leads to an approximately fourfold increase in the degradation rate. The continuous treatment allowed the study to highlight the efficiency of the new configuration of the front flow reactors developed (PFR-LED) compared to the conventional configuration. This increased efficiency is demonstrated by the fourfold increase in the specific degradation rate of the optimized PFR-LED compared to the conventional reactor. The performance evaluation of the compact and optimized configurations of the frontal flow reactor (PFR-LED Optimized) aimed to highlight the influence of the inlet concentration under different flow rates. Furthermore, the effect of the number of optical fiber supports shows that the degradation rate and selectivity are enhanced. The results were obtained using four photocatalytic media (4OF/4UV-LED) for 1.19 mmol·m−3 of cyclohexane input concentration at 18 L.min−1 of flow rate under optimal humidity conditions (38 %), constituting the ultimate rate of CO2 selectivity achieved (31 %) for an abatement of 59 %.This global investigation has allowed for the design of a new version of a compact reactor. This reactor provides an economical and efficient way to eliminate gaseous pollutants, which clearly meets the main aims of the UN Sustainable Development Goals (UN SDGs).

'Images of Ecology' and 'Ecologies of Images'

Building on Guattari’s three ecologies – the mental, natural and social –, and recently emerging discourses in documentary theory on interactive media making, co-creation and polyphony, this presentation discusses both notions of ‘images of ecology’ and ‘ecologies of images’ to fathom the potential of mobile, networked documentary media assemblages to encourage multilogue, to affectively and cognitively embrace complexity and to instigate transformation. Taking a project which is currently work in progress – the transdisciplinary polyphonic artistic research Mind the Gap! –, tentative answers are suggested to the question of how to face a situation of intermingled crises: the crisis of representation in the representation of crisis. Guiding questions are: How can one raise alert to immanent ecological risks and at the same time co-creatively awaken a desire for a more sustainable world? How can one promote awareness of ecological topics when risk is immanent but often invisible and when fundamental transformations are vital, but when, at the same time, the complexity of matters thwarts responsible action-taking? The hypothesis underlying the approach of this paper is that interactive documentary media configuration bear the potential to face both crises, especially those configurations which are based on principles of co-creation, polyphony and multi-perspectivity. This openness, I will claim, does not only do justice to the entanglement of issues at stake, but it also teaches us to listen to and to consider various viewpoints as openers to possibility spaces for negotiation and solution finding rather than fixed resolutions. Still, meaningful engagement requires multimodal competences and literacies, involving system thinking, socio-emotional aptitudes, and a cognizance of the interwovenness of the symbolic, material, phenomenological and political dimensions of ‘images of ecology’ and ‘ecologies of images’ (cf. López 2020). Hence, Mind the Gap! combines mindfulness and self-reflection with competences of mobile media making and artistic self-expression as well as socio-emotional skills to encourage experiential and experimental learning. Participants are invited to use their smartphones to create visual haikus while mindfully being in Nature. Analogousue to the literary haiku, they take three images or short videos which are shared and negotiated on a co-creative website. This growing collection serves several functions: 1) it documents the title-giving ‘gap’ that we risk due to a loss of biodiversity; 2) it presents a creative strategy to cope with a situation which either usually remains abstract and far away, or which is overwhelming and often causes resignation; 3) it is meant as a point of departure to stimulate exchange and to form a community of concern for further action taking; and 4) from a methodological perspective, strategies are deduced for multimodal eco-media literacies, responsive listening and understanding. Discourses from various traditions are brought into dialogue: theories of interactive media are reconsidered through the lens of ecocriticism and environmental humanities; concepts of mobile media making and “emplaced interaction“ (Aston 2017) meet reflections on the epistemic dimension of documentary; and principles of co-creation are related to theories of self-reflexive mindfulness and nature observation, creative expressivity and agency.

Thermal performance evaluation of a microchannel with different porous media insert configurations

PurposeThis paper aims to numerically investigate the thermal performance evaluation of a microchannel with different porous media insert configurations.Design/methodology/approachHeat transfer and pressure drop of fluid flow through a three-dimensional (3D) microchannel with different partially and filled porous media insert configurations are investigated numerically. The number of divisions and positions of porous material inside the microchannel for 12 different arrangements are considered. A control volume method is used for single-phase laminar flow with the Darcy–Forchheimer model used for the porous media. The geometry of the problem consists of a microchannel with a rectangular cross-section of 0.4 mm × 0.2 mm and length 20 mm, with a stainless steel porous material insert with a porosity coefficient of ε = 0.32 and a Darcy number of Da = 2.7 × 10−4.FindingsNumerical results show that when the transverse arrangement is used, as the number of partitions increases, the thermal performance is improved and the heat transfer increases up to 300% compared to that of the plain microchannel. Comparing the obtained results from the microchannels with transverse and longitudinal configurations, at low Reynolds numbers, the transverse arrangement of porous blocks and at high Reynold numbers, the longitudinal arrangement present the best thermal performance which is virtually four times higher compared to the obtained Nu numbers from the plain microchannel. The results show that as the volume of porous material is constant in the cases with various transverse porous blocks, the pressure drop is not changed in these cases. Also, the highest thermal performance ratio is when the porous material is placed along the walls in a longitudinal direction.Originality/valueTo the best knowledge of the authors, in the previous research, the effect of the arrangement and location of the porous medium in the transverse and longitudinal direction in the microchannel and their effect in different states on the behavior of flow and heat transfer has not been numerically investigated. In this study, the porous media configuration and its placement in a 3D microchannel were numerically studied. The effect of porous material layout and configurations in different longitudinal and transverse directions on the pressure drop, heat transfer and thermal performance in the 3D microchannel is investigated numerically.

Improving the performance of vertical flow constructed wetlands by modifying the filtering media structure.

The aim of this research was to study the influence of the bed media configuration and particle size on the treatment efficiency of subsurface vertical flow (VF) constructed wetlands (CWs) treating municipal wastewater. Two outdoor pilot units (VF1 and VF2, planted with Phragmites australis) with the configuration C1 were operated in parallel for 2 years at similar surface loading rates of 9.7 ± 3.2 (VF1) and 10.1 ± 3.3 (VF2) g biological oxygen demand (BOD5)/m2·day (19.5 ± 6.4 (VF1) and 20.4 ± 6.2 (VF2) g chemical oxygen demand (COD)/m2·day). A different configuration C2 was used during the third year at 16.9 ± 4.6 (VF1) and 18.2 ± 3.0 (VF2) g BOD5/m2·day and 26.0 ± 7.2 (VF1) and 28.0 ± 4.7 (VF2) g COD/m2·day. Two different filtering materials (1-3-mm sand for VF1 and 2-6-mm fine gravel for VF2) were used for configuration C1. The same units were modified after 2 years of operation by adding a 10-cm layer of fine sand (0-2 mm) on the top (configuration C2). In C1 conditions, the unit with the coarse material VF2 showed significantly (p < 0.05) lower removal efficiencies of total suspended solids (TSS) and BOD5 than VF1, and both units failed to meet the BOD5 discharge limit. In C2 conditions, removal efficiencies reached 82% TSS, 97% BOD5, 76-81% ammonia, and 60-66% TN, without significant differences between VF1 and VF2 units. Removal efficiencies were significantly higher for configuration C2 than that for C1, due to the positive effect of the upper fine sand layer. The presence of this fine sand layer doubled the water retention time and increased the removal rates, while the infiltration rates were high enough for an operation free of clogging.

Oleophilic and oleophobic media combinations – Influence on oil mist filter operating performance

For the filtration of fine mists, glass fiber nonwovens are commonly used as filter media, especially in high efficiency applications. For the filters, several layers of these media are usually wrapped around a cylindrical grid; often several types of media are combined to reduce pressure drop and entrainment and improve separation efficiency. The media in use typically differ in their structural and wetting properties. The media configuration, i.e., the sequence of individual media layers in the filters, is generally chosen based on empirical values.In this work, experimental studies with several configurations of filter media were carried out, investigating the operating behavior of the filters. Four media of different structure, two oleophilic and two oleophobic each were combined to determine combinations with beneficial operating properties. It was found that using media with coarse pore structure on the upstream side of the filters could significantly reduce pressure drop, while separation efficiency was slightly improved or hardly affected by the sequence of media. The reason for this improvement was found to be the impact of media sequence on liquid transport mechanisms in the filter media. Two mechanisms were identified to be responsible for the improvement of operating behavior: a.) The propagation of channels from coarse media into subsequent fine layers and therefore adaption of different channel structures and b.) The avoidance of a complete liquid film on the face of fine filter media.

Improving Network Performance of IP PBX Based Telecommunication System

IP-PBX based communication has become a human need in the era of technology. Some researchers design a wireless telecommunication system based on IP PBX using Raspberry Pi. The previous researches have small network coverage and problematic on the ability of the system to support multiple concurrent connections. Based on these problems, these research aims are to expand the coverage area and increase the number of concurrent calls. This study used Asterisk FreePBX for the media configuration of the servers. The clients: laptops and smartphone devices used Linkin and Bria softphone. The testing was conducted in terms of voice and video services in the form of signal strength, CPU performance of servers, and network performance parameters such as delay, jitter, and packet loss. The results obtained that the CPU performance of the servers for seven calls simultaneously is around 16.9% compared with previous research, at an average of 45%. Based on ETSI standards, the measurement of network performance parameters when communicating between clients outperform than previous research. The clients can communicate well up to 390 meters.&#x0D;

Use of rapid small-scale column tests for simultaneous prediction of phosphorus and nitrogen retention in large-scale filters

Rapid small-scale column tests (RSSCTs) have been previously used to predict the effluent concentration of a single nutrient in large filters with good accuracy. However, in drainage waters originating from heavy textured soils, where there is a need for in-ditch filters to retain both dissolved reactive phosphorus (DRP) and ammonium (NH4) simultaneously, the suitability of a RSSCT approach to model both parameters must be proved. In this study, a decision support tool was used to identify appropriate media that may be placed in filters for the removal of DRP and NH4. The selected media for this study were sand and zeolite. Both media were placed in acrylic tubes each with an internal diameter of 0.01 m and with lengths ranging from 0.1 to 0.4 m, and their performance for simultaneous removal of DRP and NH4 (1 mg DRP and NH4-N L−1) from water was evaluated. The data generated from the RSSCTs were used to model DRP and NH4 removals in 0.4 m-long laboratory columns of internal diameter 0.1 m, which had the same media configuration as the small columns and were operated using the same influent concentrations. The developed model successfully predicted the effluent concentration of both the DRP and NH4-N from the large columns. This indicates using RSSCTs to model the performance of filters will produce substantial savings in operational, financial and labour costs, without affecting the accuracy of model predictions.

Mass Media and Social Media Configuration Under Hugo Chavez Populist Discourse: Differences and Contrasts

Mass Media and Social Media Configuration Under Hugo Chavez Populist Discourse: Differences and Contrasts

Arbitrary Diffraction Engineering With Multilayered Multielement Metagratings

We theoretically formulate and experimentally demonstrate an analytical formalism for the design of printed circuit board (PCB) metagratings (MGs) exercising individual control over the amplitude and phase of numerous diffracted modes, in both reflection and transmission. Lately, these periodic arrangements of subwavelength polarizable particles (meta-atoms) were shown to deflect an incoming plane wave to prescribed angles with very high efficiencies, despite their sparsity with respect to conventional metasurfaces. Nonetheless, most reported MGs were designed based on full-wave optimization of the meta-atoms, with the scarce analytical schemes leading directly to realizable devices were restricted to single-layer reflecting structures, controlling only the partition of power. In this paper, we present an analytical model for plane-wave interaction with a general multilayered multielement MG, composed of an arbitrary number of meta-atoms distributed across an arbitrary number of layers in a given stratified media configuration. For a desired (forward and backward) diffraction pattern, we formulate suitable constraints, identify the required number of degrees of freedom, and correspondingly set them to yield a detailed MG configuration implementing the prescribed functionality; no full-wave optimization is involved. To verify and demonstrate the versatility of this systematic approach, fabrication-ready multilayer PCB MGs for perfect anomalous refraction and non-local focusing are synthesized, fabricated, and experimentally characterized, for the first time to the best of our knowledge, indicating very good correspondence with theoretical predictions. This appealing semianalytical methodology is expected to accelerate the development of MGs and extend the relevant range of applications, yielding practical MG designs on demand for arbitrary beam manipulation.

Battery thermal management model and structure optimization of porous composite phase change material

In recent years, with the increasing of energy shortage and environmental pollution, various industries are transforming into green and environment-friendly enterprises. Especially in automotive industry, more and more companies pay attention to the development of electric vehicles. As one kind of energy-supplied devices, lithium-ion battery is a very popular research direction. However, its thermal management problem has always been restricting the development of new energy vehicles. It is vital to solve the heat dissipation problem of lithium-ion battery. The temperature of phase change material (PCM) remains unchanged during phase transition, which makes PCM to be the ideal choice for temperature control device. Nowadays, PCM has been introduced to the thermal management of battery. However, the low thermal conductivity of PCM causes slow heat transfer rate and weakens thermal management performance. It is urgent to improve the heat transfer rate of PCM to achieve better thermal management effect. The high thermal conductivity porous media such as metal foam and expanded graphite are commonly used to prepare composite PCM and enhance PCM thermal conductivity. However, the geometric parameters and arrangements of porous media have great effects on composite PCM thermal performance. The structural optimization combined with the heat generation characteristics of battery should be further carried out to optimize the porous media configuration and obtain better thermal management performance. Based on that, a coupling model with battery heat generation and temperature control with PCM was established in present paper, where the heat generation and transfer process in battery, the heat transfer process in PCM are comprehensively considered. The copper foam/paraffin composite PCM was used as the temperature control material. The effects of PCM layer thickness and porous media on battery thermal management performance were investigated under 5C charge and discharge rate. The results show that filling porous media can effectively improve heat dissipation rate and reduce battery surface temperature. At the same time, the PCM melting rate is enhanced and heat storage density is reduced with filling porous media. When the PCM layer is small, PCM will quickly melt completely, which results in the reduction of effective temperature control time. For example, when the PCM layer thickness is 4 or 5 mm, PCM has already completely melted at the ending of one charging-discharging cycle, which causes the battery surface temperature quickly increasing. Although increasing PCM layer thickness can improve the effective temperature control time and offset the shortcoming of filling porous media, the increase of PCM layer thickness will occupy extra space, which is very unfavorable in the actual electric vehicle. A new model with partially filling copper foam is proposed in present paper to comprehensively consider the temperature control time, temperature control effect and space restriction. In the region near the battery surface, PCM filling with metal foam is used to improve PCM thermal conductivity and temperature control effect, and pure PCM without filling metal foam is used in the region far away from the battery surface to improve thermal storage density and prolong effective temperature control time. Then, structural optimization was performed to the proposed model. The results show that the partial filling copper foam structure with total PCM layer thickness of 6 mm and the 3 mm layer near battery filled with copper foam is the optimum temperature control scheme with comprehensively considering the temperature control time, temperature control effect and space restriction.

Numerical study of enhancing vehicle radiator performance using different porous fin configurations and materials

AbstractA vehicle radiator is used for cooling down the hot working fluid with airflow passing over its flow passages and fins. The proper design of the radiator is very important due to space and weight limitations in automobiles. In this study, a numerical investigation has been conducted on the improvements, which can be obtained by implementing different porous fins in the radiator channels.The effects of different porous fin configurations with the same porous media volume on the heat transfer rate and pressure drop were investigated. The coefficient of performance values were presented for evaluating the overall performance. The investigated geometries included horizontal, vertical, corrugated, and wavy‐corrugated configurations. The results showed that the corrugated pattern had the best thermal performance among these geometries while the horizontal configuration presented the lowest pressure loss, even though the best overall performance belonged to wavy‐corrugated configuration. After selecting this configuration, the influence of different porous materials on the radiator performance was studied. Finally, the radiator with the optimum porous media configuration and material was compared to a conventional radiator. It was found that implementing this porous media in the radiator channels improves its overall thermal performance factor up to 237%.

Experiment and simulation of layered bioretention system for hydrological performance

Abstract Bioretention can reduce surface runoff, slow down peak flow, and delay peak time by increasing the infiltration capacity of the underlying surface. The media structure directly affects the performance of bioretention systems. Four pilot tanks with different media configuration were built, and hydraulics and water volume reduction were studied though intermittent, simulated storm events. The results showed that water volume and peak flow reduction rate were the most stable and efficient for #1 (fly ash mixing sand, 1:1 by volume) than other systems, which were 58.6–67.9% and 72.0–86.4%, respectively. Partial least squares regression (PLS) was used to build a model for the relation between water volume reduction rate and its influencing factors (R2 = 0.76), and the factors that influence bioretention water volume reduction were ranked from strongest to weakest as follows: infiltration rate (IR) &amp;gt; submerged area height (SAH) &amp;gt; inflow volume (IV) &amp;gt; antecedent dry time (ADT). In addition, volume reduction rate exhibited a positive correlation with ADT and SAH, and a negative correlation with IR and IV. Three water transfer simulations with different infiltration rates were conducted using HYDRUS-1D under designed inflow conditions, and the minimum relative error is obtained for #1.

Evaluation on the suspended solids and heavy metals removal mechanisms in bioretention systems

Application of bioretention systems in Korea is highly considered due to its minimal space requirements, appropriateness as small landscape areas and good pollutant removal and peak hydraulic flow reduction efficiency. In this study, the efficiency of two lab-scale bioretention types having different physical properties, media configuration and planted with different shrubs and perennials was investigated in reducing heavy metal pollutants in stormwater runoff. Type A bioretention systems were planted with shrubs whereas type B were planted with perennials. Chrysanthemum zawadskii var. latilobum (A-CL) and Aquilegia flabellata var. pumila (A-AP) respectively were planted in each type A bioretention reactors while Rhododendron indicum linnaeus (B-RL) and Spiraea japonica (B-SJ), respectively were planted in each type B bioretention reactors. Results revealed that the four lab-scale bioretention reactors significantly reduced the influent total suspended load by about 89 to 94% (p<0.01). Type B-RL and B-SJ reactors reduced soluble Cr, Cu, Zn, and Pb by 28 to 45% that were 15 to 35% greater than the soluble metal reduction of type A-CL and A-AP reactors, respectively. Among the pollutants, total Cr attained the greatest discharged fraction of 0.52-0.81. Excluding the effect of soil media, total Pb attained the greatest retention fraction in the bioretention systems amounting to 0.15-0.34. Considering the least discharge fraction of heavy metal in the bioretention system, it was observed that the bioretention systems achieved effectual reduction in terms of total Cu, Zn and Pb. These findings were associated with the poor adsorption capacity of the soil used in each bioretention system. The results of this study may be used for estimating the maintenance requirements of bioretention systems.

Entre o contratual e o polêmico: valor e representatividade nas narrativas mercadológicas

Na configuração midiática contemporânea em rede, discursos antes consolidados por vozes autorizadas que eram construídas a partir de relações unidirecionais são alterados para uma dimensão horizontal, em meio à proliferação de sujeitos que passam a se posicionar na disputa de narrativas. Indivíduos comuns e grupos sociais organizados, que costumavam desfrutar de baixa visibilidade, têm sua competência de enunciação estendida. Aumenta, assim, a incidência de discursos opostos. Diante desse risco, importantes marcas retomam sua posição de autoridade na publicidade, adotando a estratégia de assumir valores polêmicos em suas narrativas, como modo de atingir a visibilidade. Exemplares desses fenômenos da dinâmica do poder são analisados sob a perspectiva da sociossemiótica, ancorada na teoria semiótica de Greimas.

Assessment of Heat Transfer Enhancement Using Metallic Porous Foam Configurations in Laminar Slot Jet Impingement: An Experimental Study

An experimental study using the liquid crystal thermography technique is conducted to investigate the convective heat transfer performance in jet impingement cooling using various porous media configurations. Aluminum porous foams are used in the present study. Four impinging jet configurations are considered: jet impingement (1) without porous media, (2) over the porous heat sink, (3) with porous obstacle case, and (4) through porous passage. These configurations are evaluated on the basis of the convective heat transfer enhancement for two different Reynolds numbers of 400 and 700. Jet impingement with porous heat sink showed deterioration in the average Nusselt number by 9.95% and 18.04% compared to jet impingement without porous media configuration for Reynolds numbers of 400 and 700, respectively. Jet impingement with porous obstacles showed a very negligible enhancement in the average Nusselt number by 3.48% and 2.73% for Reynolds numbers of 400 and 700, respectively. However, jet impingement through porous passage configuration showed a maximum enhancement in the average Nusselt number by 52.71% and 74.68% and stagnation Nusselt numbers by 58.08% and 53.80% compared to the jet impingement without porous medium for Reynolds numbers of 400 and 700, respectively. Within the porous properties considered, it is observed that by decreasing the permeability and porosity the convective heat transfer performance tends to increase.

Assessment of recycled glass and expanded clay in a dual media configuration for drinking water treatment

ABSTRACTThe aim of this study was to investigate the overall performance of different types of recycled glass media with the optimized coagulation conditions for drinking water treatment. Tests were performed using a laboratory-based filtration unit, with dual filter media configurations and synthetic raw water. The glass media showed comparable performance for both filtration and backwashing and avoided the breakthrough of particles in the effluent. Moreover, the promising performance of the glass media was a slow head loss development which should grant longer filtration runs, less backwashing requirement and thus possible clean water and energy savings. Finally, the optimized combination of filtration media and coagulation operations can lead to the best filtration performance.