Residence Time Distribution (RTD) theory is revisited and tracer technology discussed. The background of RTD following Danckwerts ideas is presented by introducing “distribution” functions for ...residence time, internal age and intensity function and how to experimentally obtain them with tracer techniques (curves C and F of Danckwerts). Compartment models to describe fluid flow in real reactors are reviewed and progressive modeling of chromatographic processes discussed in some detail. The shortcomings of Standard Dispersion Model (SDM) are addressed, the Taylor-Aris model discussed and the Wave Model of Westerterp’s group introduced. The contribution of Computational Fluid Dynamics (CFD) is highlighted to calculate RTD from momentum and mass transport equations and to access spatial age distribution and degree of mixing. Finally smart RTD and future challenges are discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Acoustic streaming reduces axial dispersion in Poiseuille flows.•Lateral mass transfer reduces the vessel dispersion number by half.•Acoustic streaming halves the C-term of the plate height ...equation.•The flow velocity can be doubled with similar chromatographic performance.
Flow physicochemical processes, like adsorption/desorption-based separations and chemical conversions in open rectangular microfluidic channels are fundamentally limited by axial dispersion. In this contribution, the implementation of acoustics is investigated to reduce axial dispersion in microchannels. The extent of dispersion reduction is studied by means of plug injections. It was observed that the long range vortex flow of acoustic streaming can efficiently reduce dispersion by more than a factor of two. The observations made in the present study pave the way towards the development of novel, highly efficient analytical or preparative separations and microreactors with uniform residence time distributions. We elaborate on the practical implementations of both areas.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Penelitian ini bertujuan untuk menganalisis kepuasan konsumen terhadap kualitas produk yang dilakukan pada tempat makan ‘Bebeke Om Aris’ Bogor. Metode analisis yang digunakan adalah Importance ...Performance Analysis (IPA) dan diagram kartesius. Responden yang digunakan sebanyak 96 responden dengan metode convenience sampling. Hasil penelitian menunjukkan bahwa kepuasan konsumen tertinggi terdapat pada atribut tampilan penyajian makanan dengan tingkat kesesuaian 98,99%. Kepuasaan konsumen terendah terdapat pada atribut tekstur bebek tidak alot dengan tingkat kesesuaian 80,67%. Kuadran A menunjukkan atribut penting namun belum sesuai yang diharapkan konsumen yaitu aroma makanan yang sedap.
The online following of conspiracy theory believers known as QAnon has recently come into focus of U.S. government agencies and terrorism scholars, raising questions about the risk of violence it ...poses. To address these questions, as well as to triangulate existing research on QAnon’s threat, the present study compared survey responses about actual radical intention and activist intention scores of QAnon supporters (n = 113) and non-QAnon participants (n = 287), relative to QAnon’s radicalization as perceived by non-QAnon participants. Actual radical intention scores for QAnon supporters were significantly lower than the perceptions of QAnon radical intentions, and were not significantly different than the actual radical intention scores for non-QAnon participants. Activist intention scores were lowest among QAnon supporters, followed by non-QAnon supporters, and then by perceptions of QAnon activist intentions. The implications of the results for public policy are discussed.
•To rigorously extend the first order estimate of vertical distribution on small time scale.•To account for high order effects as skewness and kurtosis by the Aris-Gill expansion method.•To ...illustrate the impact of damping vegetation factor on performance of series expansion and contaminant transport in wetland flows.
Hydrological processes of contaminant transport in wetland flows are characterized by environmental dispersion. For concentration distribution of scalar dispersion, the preliminary estimate of vertical distribution (Wu et al., 2015) on small time scale is rigorously extended to account for high order effects as skewness and kurtosis. Based on a combination of Aris’ method of concentration moments and Gill’s generalized dispersion model, up to fourth order terms of vertical distribution functions and full-time two-dimensional concentration distribution are derived. The increments of damping factor, mainly representing the density of vegetation in wetlands, is shown to strengthen the mean distribution asymmetry and reduce the longitudinal dispersivity (with respect to skewness and kurtosis), and to increase the non-uniformity of vertical distribution. Therefore, dense vegetation corresponding to a large damping factor will postpone the time when Taylor’s dispersion model holds, and the first order approximation becomes rough on small time scale, demanding higher order modifications. The results provide more detailed and more accurate analytical solution for the typical environmental dispersion in wetland flows.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•Automated imaging sonar fish counts are desired but currently not common.•Echoview software and postprocessing was used for automated fish counts.•Good agreement for upstream counts, larger ...differences in downstream counts.•Filtering removed dynamic noise and milling fish from the fish tracks.•A model predicted if a downstream moving object was a fish or not.
Imaging sonars, such as the Adaptive Resolution Imaging Sonar (ARIS; Sound Metrics Corp.) produce continuous stream of sonar video footage, and they are commonly used for counting and sizing migrating fish in rivers. Although automated methods have been developed for processing imaging sonar data, manual analysis of the data is still common in fish population monitoring projects. In this study, we used Echoview software to automatically produce fish counts from long-range (up to 30 m) imaging sonar data in a prominent Atlantic salmon (Salmo salar) river; the Little Southwest Miramichi River, New Brunswick, Canada. We added postprocessing steps to address sources of error that have been reported in previous studies: 1) Major Axis Distance was used to filter out erroneous fish tracks (89 % of dynamic noise and 67 % of milling fish in the test-set) and to calculate the swimming direction (96 % correct), and 2) a logistic regression (target length, average speed, and absolute fish track change in range) was used to predict downstream moving fish from other objects with a test-set accuracy of 84 %. When 15-min tally counts were compared between computer-generated data and multiple human-generated counts, the mean of differences varied between -39 % and 65 % in the upstream counts in different datasets, and different analysis methods were in a good agreement between each other (ICC = 0.79). There were larger differences in the downstream counts where the mean of differences varied between 14 % and 115 % and there was no agreement between the datasets (ICC = 0.03). With a double-tracking method where the fish were tracked twice, the computer analysed the 24 -h datasets in 500−600 min and was slower than human-generated counts that required 200−600 min, however, computer generated-counts can be derived in the background without the presence of a technician and may produce significant savings in personnel cost.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Assessment and monitoring of marine biodiversity, including fish populations, is essential for evidence-based conservation management of coastal marine resources. The effectiveness of monitoring ...techniques for stock assessment varies with sea conditions. In dynamic marine environments with high turbidity, such as those found in estuaries, mangroves, coastal straits, fjords, and bays, traditional assessment methods include the use of destructive techniques such as trawling. Hydroacoustic sampling techniques overcome such restrictions, equipment such as echosounders have commonly been used for biodiversity assessments including fish community structure, biomass, behaviour, and dynamics studies. However, hydroacoustic methods have been shown to be less reliable for species identification.
The high frequency Adaptive Resolution Imaging Sonar (ARIS) is widely used for underwater object detection and imaging. Our study investigated the suitability of ARIS 3000 for the species identification of North-East Atlantic marine species using experimental aquarium studies, field surveys and multi investigator assessments. Aquaria results showed that 82 % of species were detected by observers, of which five were identified correctly identified consistently. The remaining four species were identified correctly <67 % of the time. During field surveys, a 150 % higher confidence in identification was given to more morphologically distinct groups such as elasmobranchs.
Whilst our results highlight the suitability of the ARIS for accurate and repeatable identification of some of the model species used in this study, we have also shown that factors such as size and morphological traits limit the accuracy of identification for all species. We suggest that monitoring techniques combine the use of ARIS sonars alongside other sampling tools for assessing motile faunal communities.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Quantitative description of the advection-diffusion behavior in a single fracture is of fundamental importance for the accurate evaluation of the solute transport behavior and properties, and even ...for the analysis of the complex hydrodynamic problems. However, the surface roughness and mismatch featured in natural fractures significantly affect the solute advection-diffusion process, with the effect from latter not been fully verified. In this work, the effects of surface roughness and mismatch on advection-diffusion process were reexamined, four control factors (i.e., local roughness factor (fr), hydraulic tortuosity (τ), surface tortuosity (τs), and surface mismatch factor (fm)) were identified by analytical derivation, and a new modified Taylor-Aris equation was accordingly established. To further reveal the influence mechanism of surface roughness and mismatch on advection-diffusion behavior, a series of Lattice Boltzmann simulations of the advection-diffusion process were conducted. Results indicate that, surface roughness and mismatch affect the advection-induced dispersion behavior both in the form of decreasing the average fluid velocity, with an inverse S-shaped decreasing relationship presented between the latter and the average fluid velocity. Moreover, the influence of surface mismatch on advection-diffusion is independent of surface roughness, and the advection-induced dispersion is inversely proportional to frτ2τs6fm4.5. Numerical comparison demonstrated the performance of our modified model, and its generalization was approved by theoretical analysis.
•Four controlling factors for advection-diffusion process through mismatched fractures were identified.•The effect of surface mismatch on effective diffusion coefficient was specified.•The influence mechanism of surface mismatch on advection-induced dispersion was revealed.•A general advection-diffusion transport model with specified parameters was established.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this paper, we attempt to provide a perspective on the field of process systems engineering (PSE) by tracing its evolution back to the pioneering work of Neal Amundson, Rutherford Aris, and Roger ...Sargent, and highlighting their legacies that continue to guide research in PSE to this day. We underscore the growth in the technical scope of the field from the adoption of control and optimization methods for analyzing chemical engineering problems to the advancement of the methods themselves. We comment on the extended scope, current state, and major trends in PSE while reflecting on the intellectual identity of our field that has developed over time. PSE is positioned to play a crucial role in addressing major societal challenges, such as sustainability and health. While considering a diverse set of applications, it will also be critical to further advance theory which allows us to address the complexity that underlies these problems. Finally, we outline a few emerging research themes that could serve as initial food for thought in a broader discussion on future research directions in PSE.
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GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We present a C-band amplifying reconfigurable intelligent surface (ARIS) integrated with power amplifier (PA) to enhance the reflected electromagnetic (EM) signals. An aperture-coupled patch element ...with two orthogonal hourglass-shaped slots is elaborately constructed to ensure a broad operation bandwidth. A power combining and dividing network is also introduced to combine the 2 <inline-formula> <tex-math notation="LaTeX">\times2 </tex-math></inline-formula> elements into a subarray to reduce the number of PAs and the system cost. The simulation results indicate that the achieved gain of ARIS is 7.7-12.2 dB from 5.0 to 6.0 GHz. A prototype of the proposed ARIS is designed, fabricated, and experimentally verified. The measured results agree well with the simulation. The proposed ARIS is promising for applications in future wireless communication systems for signal enhancement and coverage extension.
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