Best Configuration In Terms Research Articles

Empirical Analysis of Mining Costs Amid Energy Price Volatility for Secondary Deposits in Quarrying

The outlined methodology for calculating operating costs in open-cast mines and quarries not only facilitates the selection of optimal mining equipment and systems for working lower-grade secondary deposits but also adds significant value in navigating the challenges of fluctuating prices of energy carriers and fuels. Moreover, the study rigorously assesses the impact of mining operations on the performance of deployed mining equipment and the overall viability of the rock mining project. The selection procedure relies on a comprehensive analysis of the technical and economic parameters of selected solutions, providing critical insights to guide decisions regarding the continuation or discontinuation of mining operations. We analyse, based on empirical data, the technical and economic parameters of several variants of mining equipment to be used for the extraction of rocks and stones from secondary deposits in conditions of fluctuation depending on the level of energy prices, in order to find the best configuration in terms of operating costs and potential revenue. In addition to analysing the structure of operating costs, the article presents their correlation with the required profit from the sale of raw materials using the linear correlation method. The results clearly demonstrate the economic viability of mining secondary deposits, taking into account the actual costs incurred by mining companies.

Effect of reinforcement ratio and textile pre-impregnation on the mechanical properties of flax textile reinforced sulfoaluminate matrix

This study evaluates the effect of reinforcement ratio and textile pre-impregnation on the tensile behavior of flax textile, embedded in an inorganic CSA matrix (sulfoaluminate cementitious matrix), known as Fabric Reinforced Cementitious Matrix (FRCM). Two reinforcement ratios of (3 and 6%) and two impregnation techniques (polymeric and mineral) are applied. Direct tensile tests are conducted on FRCM specimens as well as on bare flax textiles featuring three configurations: NP (non-impregnated), PP (polymeric-impregnated), and PM (mineral-impregnated), between 1L (one layer) and 2L (two layers) of flax textile. The results show a direct correlation between the reinforcement ratio and the enhancement of mechanical properties, with a notable 44% increase in mechanical strength observed for NP FRCM specimens between 1L and 2L of flax textile. Mineral pre-impregnation enhances yarn-cement matrix bonding inside FRCM, while FRCM specimens with polymeric-impregnated textiles have limited influence on the mechanical properties due to premature failure. Polymeric impregnation has a pronounced effect when applied to bare flax textiles, with PP flax textiles demonstrating exceptional mechanical strength and rigidity, reaching up to 480 MPa and 37 GPa, respectively. In contrast, this effect was mitigated when employing PP textiles in FRCM specimens, where the lowest fabric efficiency reached 12% for the 2L.PP configuration suggests significant chemical incompatibility between epoxy resin and CSA matrix. Mineral-impregnated specimens display consistent efficiency regardless of reinforcement ratio, suggesting a novel and homogeneous distribution of cement matrix particles within the yarns of textiles. Two distinct failure modes of FRCM are observed in this study, a delamination for PP configurations and a fiber pullout for NP and PM configurations. No effect of reinforcement ratio is remarked on the failure mode. The cracking mode in PM FRCM configurations showcased improved aesthetics, durability, and elongation after rupture (6.28%). As a result, 2L.PM FRCM is the best configuration in terms of mechanical strength, rigidity, ductility, and durability.

Lateral compression behavior of expanded polypropylene foam–filled carbon and glass fiber composite tubes

Abstract The crashworthiness and deformation behavior of circular composite tubes that were internally supported with expanded polypropylene (EPP) foams were investigated under lateral compression tests. Carbon woven (CFRP) and glass woven fiber/epoxy (GFRP) composites and EPP foam with densities of 30, 60, and 75 kg·m−3 were used. According to results, empty CFRP and GFRP tubes absorbed almost the same amount of energy; however, the GFRP tube had a higher specific energy absorption value due to its lower weight compared to the CFRP tube. EPP foam filling has a more significant effect on the crashworthiness of CFRP tubes compared to GFRP tubes. The best results in CFRP tubes, in terms of specific energy absorption, were obtained as 2.67 J g−1 at 75 kg·m−3 EPP foam-filled sample; however, 60 kg·m−3 EPP foam–filled sample exhibited the best configuration in terms of force efficiency. For the GFRP tubes, the best configuration was obtained at 60 kg·m−3 EPP foam–filled sample for all of the crashworthiness parameters. It is seen that the crushable length of composite tubes was shortened with the increase of EPP foam density. Lastly, the deformation behaviors of composite tubes showed that the CFRP tubes were more brittle than the GFRP tubes.

Dynamic behaviour of multi-stage crash energy absorption systems integrated with MRA: Simulation and analysis

The research work focuses on development of mathematical models to study on the dynamic behaviour of a multi-stage crash energy absorption system (MSCEAS) suitable for cars. The proposed energy absorption system can be attached in the front overhang of the vehicle, which comprises of a bumper, magneto-rheological absorber (MRA), friction spring, and piston-cylinder with shear plate assembly (PCSPA).11MSCEAS - Multi-stage crash energy absorption system, MRA-Magneto-rheological absorber, PCSPA-Piston-cylinder with shear plate assembly, LPM- Lumped parameter model, DoF-Degrees of freedom, MBWM-Modified Bouc–Wen model. These components are arranged in series where in, MRA plays a vital role as it transforms passive system in to semi-active. The entire system has been characterized as lumped parameter model (LPM). The real-time crash test of Dodge-Neon vehicle is utilized to create the base model with four degrees of freedom (DoF) LPM and parameters including mass, stiffness, and damping coefficient are chosen based on vehicle’s structural components. The MRA has been modelled based on modified Bouc–Wen model (MBWM) and the optimized parameters are selected from existing literature while considering the high damping capability of MRA. Four models have been proposed by interchanging the energy absorbing elements so as to obtain the best configuration in terms of crash kinematics. Numerical analysis is performed for both base vehicle and vehicle assembled with the proposed models based on crash kinematics of occupant’s cabin. It is found that, one among the four models exhibit appreciable reduction in intrusion displacement during low to high-speed collisions. Whereas, another proposed model exhibits considerable decrement in deceleration patterns. Further, behaviour of four absorption elements has also been captured for various impact speeds and voltages supplied to MRA and presented in this work. The current research is carried out to protect the occupants from dangerous vehicle crashes by integrating a MSCEAS based on MRA as a critical add-on.

Life Cycle Assessment of an Integrated PV-ACAES System

The aim of this paper is to evaluate the overall life cycle environmental impact of an adiabatic compressed air energy storage (ACAES) system, which is designed to achieve the best match between the power production of a photovoltaic (PV) power plant and the power demand from the final user. The electrical energy demand of a small town, with a maximum power load of about 10 MW, is considered a case study. The ACAES system is designed with a compressor-rated power of about 10 MW and charging and discharging times of 10 and 24 h, respectively. Different sizes of the PV plant, ranging from 20 to 40 MWp, and two different solutions for the compressed air storage, an underground cavern, and a gas pipeline, are analyzed. The aim of this analysis is to compare the impacts on human health, ecosystem quality, climate change, and resource consumption of the PV power generation plant and the integrated PV-ACAES system with those of a reference scenario in which the end user demand is met entirely by the grid. The best results in terms of a reduction in environmental impact in comparison to the reference scenario are obtained for a small PV plant (20 MW) without the ACAES section, with reductions of about 85–95% depending on the category of impact. The integration of the ACAES system improves energy self-consumption but worsens the environmental impact, especially for air storage in gas pipelines. The best configuration in terms of environmental impact is based on a 30 MW PV plant integrated with an ACAES section using an underground cavern for air storage and allows for improvements in the energy self-consumption of between 38% and 61%, with a reduction in the environmental impact compared to the reference scenario of about 80–91% depending on the impact category.

Consideration of the learning effect in the comparison of Fixed Worker and Walking Worker assembly systems

Market demand is always more characterized by products variability and life cycle reduction; consequently, manufacturing systems need to be always more flexible and adaptable, in order to well react to this fluctuating demand. The most common assembly systems configuration is the Fixed Worker (FW) assembly line, where the workers always remain in the same workstation, to perform a single and often repetitive set of assembling tasks characterized by manual operations. On the other side, in the Walking Worker (WW) assembly line each operator travels along the workstations of the line performing all assembly tasks. In this context, the introduction of a new product, or a new worker, has an effect on the performance of the assembly system, caused by the learning of the new tasks. This paper aims to investigate the learning effect on the FW and WW systems and to compare them in order to define the best configuration in terms of performance. In particular, it proposes a mathematical model to represent the learning effect, also applying it to a numerical example. Results show that FW configuration is preferable in standard condition, while when the throughput is fluctuating, WW system is better in terms of performance. Future research will extend this study to more case studies in order to better understand the trend of this correlation, also considering particular phenomena like workers’ absenteeism and turnover.

Early bread mold detection through microscopic images using convolutional neural network

Mold on bread in the early stages of growth is difficult to discern with the naked eye. Visual inspection and expiration dates are imprecise approaches that consumers rely on to detect bread spoilage. Existing methods for detecting microbial contamination, such as inspection through a microscope and hyperspectral imaging, are unsuitable for consumer use. This paper proposes a novel early bread mold detection method through microscopic images taken using clip-on lenses. These low-cost lenses are used together with a smartphone to capture images of bread at 50× magnification. The microscopic images are automatically classified using state-of-the-art convolutional neural networks (CNNs) with transfer learning. We extensively compared image preprocessing methods, CNN models, and data augmentation methods to determine the best configuration in terms of classification accuracy. The top models achieved near-perfect F1 scores of 0.9948 for white sandwich bread and 0.9972 for whole wheat bread.

Comparison of different RGB InP-quantum-dot-on-chip LED configurations.

InP/ZnSe/ZnS quantum dots (QDs) offer a cadmium-free solution to make white LEDs with a narrow blue, green and red emission peak. Such LEDs are required for display and lighting applications with high color gamut. An important phenomenon that hampers the efficiency of such quantum-dot-on-chip LEDs is re-absorption of already converted light by the QDs. Proposed solutions to remedy this effect often rely on complex or cost-ineffective manufacturing methods. In this work, four different RGB QD-on-chip LED package configurations are investigated that can be fabricated with a simple cavity encapsulation method. Using accurate optical simulations, the impact of QD re-absorption on the overall luminous efficacy of the light source is analyzed for these four configurations as a function of the photo-luminescent quantum yield (PLQY) of the QDs. The simulation results are validated by implementing these configurations in QD-on-chip LEDs using a single set of red and green emitting InP/ZnSe/ZnS QDs. In this way, the benefits are demonstrated of adding volume scattering particles or a hemispherical extraction dome to the LED package. The best configuration in terms of luminous efficacy, however, is one where the red QDs are deposited in the recycling cavity, while the green QDs are incorporated in the extraction dome. Using this configuration with green and red InP/ZnSe/ZnS QDs with a PLQY of 75% and 65% respectively, luminous efficacy of 102 lm/W was realized for white light with a CCT of 3000 K.

Fused silica ablation by double ultrashort laser pulses with dual wavelength and variable delays.

Today, glass and other similar dielectric materials are widely used in modern manufacturing. However, glass is a brittle and a heat sensitive material. Laser technology is used to process glass but quality and throughput are still a key issue. In the present paper, we investigate dual-wavelength double ultrashort laser pulses in order to control free electrons dynamics and subsequent ablation for fused silica processing, and further improve the understanding of this laser-material interaction. We used a high average power Yb-doped femtosecond laser source (100 W) with two optical lines exhibiting different pulse durations and wavelengths (500 fs at 515 nm; and 1 or 10 ps at 1030 nm) with various fluences and delays. The best configuration in terms of ablation efficiency is expected to take place when the green pulse first induces free electrons, followed by their heating by the red pulse. The obtained results are discussed in terms of optical transmission as well as ablated volume, and are compared with single pulse ablation. Our experimental results are supported by absorbed energy density calculations based on a model considering the two-color laser induced electron dynamics, including photoionization, laser heating of free electrons, and their recombination. We demonstrate that there is an optimal cooperating effect between the two sub-pulses for a 1-ps delay, nevertheless there is no beneficial effect in splitting the beam for optimizing fused silica ablation compared with the single-pulse green configuration.

Solar Access Assessment in Semi-Arid Urban Context: An Application Study for Ten Urban Forms of Existing Apartment Buildings Districts in Batna City, Algeria

The building sector has become one of the largest energy consumers in developing countries and should be considered a significant target for implemented energy-saving initiatives. The use of renewable energy, especially solar energy, could significantly reduce the dependence on fossil fuels. This paper analyzes the relationship between urban morphology and solar availability under the semi-arid climate and environmental conditions of Batna city (Algeria). A Grasshopper-based automated morphology generation and simulation system for evaluating solar access has been developed. Morphological and solar analyses of ten representative residential fabrics of Banta's collective housing stock were performed to compare and identify the best configuration in terms of solar technology use. Four solar performance indicators have been assessed: (i) Building Integrated Photovoltaic Index (BIPVi), (ii) Active Solar Collector index (ASCi), (iii) Passive Solar Index for Heating (PSI_heating), and (vi) Passive Solar Index for Cooling (PSI_cooling). Findings suggest that roofs receive three times more annual solar irradiation than facades and about four times more in Summer. Moreover, Samples showing consistent building height, low volume-to-area ratio, low site coverage, low density, and detached configuration get the best results of solar performance indicators. Finally, active solar collectors appear to be the most effective solar technology in the studied context.

A Temperature Sensor Exploiting Plasmonic Phenomena Changes in Multimode POFs

A novel sensing method for temperature measurements of liquids, exploiting plasmonic resonance in multimode plastic optical fibers (POFs), has been devised. The possibility to measure the temperature is useful in several application fields of plasmonic sensors, such as when a binding test between a receptor and an analyte occurs, considering that the binding parameters are a function of the temperature. The novel temperature sensor consists of two different D-shaped POF connected in a cascade. The first element is a thermosensitive platform with a thin silicone layer on the POF core, whereas the second is a conventional surface plasmon resonance (SPR) D-shaped POF sensor. The operating principle of the novel temperature sensor is based on the variations of light launch conditions in the SPR-POF sensor as a consequence of the temperature changes in the solution covering the thermosensitive platform. In this way, the input light ray angle changes with the temperature, producing a shift in resonance wavelength conditions. The proposed sensor has been tested, as proof of concept, in a temperature range from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$20^{\circ }\text{C}$ </tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$38^{\circ }\text{C}$ </tex-math></inline-formula> with a step size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3^{\circ }\text{C}$ </tex-math></inline-formula> , to establish the role of the silicone layer on the thermosensitive platform and the best configuration in terms of sensitivity.

Mechanical characterization of yarns made from carbon nanotubes for the instrumentation of particle beams at CERN

Existing copper-coated carbon fibers used in wire scanners to measure the transverse beam profile in the accelerators at CERN are approaching material limits. A new instrument design has showed that the main limitation now comes from the centerpiece of the instrument: the wire. Large amplitude vibrations increase the risk of failure during scans. New required specifications concerning the beam measurements for the Future Circular Collider (FCC) project cannot be met. Fortunately, the commercial development of long microscopic yarns made of spun carbon nanotubes has paved the way for possible alternatives. The objective of this study is to determine if those Carbon NanoTube Yarns (CNTY) could replace the current carbon fibers (CF) for beam instrumentation, and if so, to determine the best configuration in terms of diameters and mounting system. To do so, we have made extensive testing and microscopy on CNT yarns with diameters of 10, 20 and 30 μm, with two different mounting systems, the Paper Frame conditioning (PF) or partial Copper-Coated conditioning (CC). A Weibull approach was used to extrapolate our results to the real length of the wires used in operational instruments. This study shows that considering the Weibull criteria, the best configuration to increase the accuracy of the beam profile measurement is to use a not copper-coated 20 μm diameter CNTY.

Low-Cost Heaving Single-Buoy Wave-Energy Point Absorber Optimization for Sardinia West Coast

This work presents the Water Energy Point Absorber (WEPA), which is a heaving single-buoy point absorber optimized for a specific site off the west coast of Sardinia Island. The aim of the study is to present the optimization process undertaken to identify the best configuration in terms of performance and cost. The optimization is carried out thanks to a simulation tool developed in Matlab-Simulink environment and verified through to the commercial software Orcaflex. Simulations are performed in the time domain with the installation site’s waves as input. The hydrodynamics parameters are computed thanks to the commercial software Ansys Aqwa and given to the model as input. The yearly energy production is computed as output for each configuration. Several parametric analyses are performed to identify the optimal Power Take Off (PTO) and buoy size. Among the main findings, it shall be mentioned that the PTO-rated torque has a strong influence on the energy production, higher PTO-rated torque proved to have better performance. The optimal hull size is strictly related to the incoming waves, and for the given site the smaller hulls are performing better than larger ones. The hull height, hull mass and hull draft have little impact on productivity. Finally, a comprehensive techno–economic analysis is performed, showing that the best configuration can be identified only after a detailed feasibility study and rigorous cost analysis.

Numerical analysis for thermal management of data center with phase change material

PurposeThe purpose of this paper is to analyze the performance of a data center and thermal management by using phase change material (PCM). Numerical studies were conducted for two dimensional model of data center and installation of PCM at different locations.Design/methodology/approachFinite volume method was used for the unsteady problem, while impacts of air velocity and PCM location on the flow field, thermal pattern variations and phase change dynamics were evaluated. Three different locations of the PCM were considered while air velocity was also varied during the simulation. Thermal field variations and cooling performance of the system for different PCM location scenarios were compared.FindingsIt was observed that the installation of the PCM has significant impacts on the vortex formation, thermal field variation within the system and its performance. The left, right and top wall installation of the PCM changed the thermal patterns near the heat cell of the data centre. The phase change process is fast for the upper wall installation of the PCM, while the discrepancy of the melt fraction dynamics between different air flow at this position is minimum. The case where PCM placed in the upper wall at the highest air velocity is the best configuration in terms of heat storage. The utilization of PCM and changing its locations provide an excellent tool for thermal management and cooling performance of data centre.Originality/valueResults of this study can be used for initial design and optimization of cooling systems for thermal management of data centers while the importance of the high-performance computing becomes very crucial for the advanced simulations in different technological applications.

Supercritical CO2 Binary Mixtures for Recompression Brayton s-CO2 Power Cycles Coupled to Solar Thermal Energy Plants

In this work, an evaluation and quantification of the impact of using mixtures based on supercritical carbon dioxide “s-CO2” (s-CO2/COS, s-CO2/H2S, s-CO2/NH3, s-CO2/SO2) are made as a working fluid in simple and complex recompression Brayton s-CO2 power cycle configurations that have pressure drops in their components. These cycles are coupled with a solar thermal plant with parabolic-trough collector (PTC) technology. The methodology used in the calculation performance is to establish values of the heat recuperator total conductance (UAtotal) between 5 and 25 MW/K. The main conclusion of this work is that the cycle’s efficiency has improved due to using s-CO2 mixtures as working fluid; this is significant compared to the results obtained using the standard fluid (pure s-CO2). Furthermore, a techno-economic analysis is carried out that compares each configuration’s costs using pure s-CO2 and a mixture of s-CO2/COS with a molar fraction (70/30), respectively, as working fluid where relevant results are obtained. These results show that the best configuration in terms of thermal efficiency and cost is the RCC-RH for pure sCO2 with values of 41.25% and 2811 $/kWe, while for the mixture sCO2/COS, the RCC-2RH configuration with values of 45.05% and 2621 $/kWe is optimal. Using the mixture costs 6.75% less than if it is used the standard fluid (s-CO2).

Identification of flow states around three staggered square cylinders at two symmetrical arrangements by a numerical investigation

The fluid flow over three staggered square cylinders at two symmetrical arrangements has been numerically investigated in this study. The numerical calculations are carried out for several values of the Reynolds number (Re) ranging from 1 to 180. The results are presented in the form of vorticity contours and temporal histories of drag and lift coefficients. Furthermore, the physical parameters, namely, the average drag and lift coefficients and Strouhal number are presented as a function of Re. Two different states of flow are found in this work by systematically varying Re: steady and unsteady states. The transition to unsteady state regime is exhibited via Hopf bifurcation first in the second configuration followed consequently by the first one with critical Reynolds number of Re[Formula: see text] and Re[Formula: see text], respectively. It is observed that the bifurcation point of the steady regime to the unsteady one is very much influenced by the change in the geometry of the obstacle. The unsteady periodic wake is characterized by the Strouhal number, which varies with the Reynolds number and the obstacle geometry. Hence, the values of vortex shedding frequencies are estimated for both the considered configurations. Computations obtained also reveal that the spacing in the wake leads to reducing the pressure and enhancing the fluid flow velocity for both arrangements by monotonically strengthening the Reynolds number value. Furthermore, the drag and lift coefficients are determined, which allowed determining; the best configuration in terms of both lift and drag. It is observed that the drag force is dependent on the obstacle geometry and strengthens while lowering the Reynolds number. On the other hand, an opposite trend of the lift drag evolutions is observed for both configurations and considerably affected by the arrangements shape.

Optimization of tritium breeding ratio in ARC reactor

Abstract Affordable Robust Compact reactor is a conceptual design for a Tokamak conceived by Massachusetts Institute of Technology (MIT) researchers. The design of this tokamak is under development and update. One of the key parameters for fusion reactor power plants is the tritium breeding ratio (TBR), which has to guarantee the tritium self-sufficiency. The tritium inventory circulating in a fusion power plant must be minimized. In the meantime, to enhance plant’s economics, the amount of tritium generated and stored should be maximized, since it would be used to startup new reactors. Both of the aforementioned trends meet their best in a TBR as high as possible. In this work, ARC tritium breeding ratio is studied and optimized. Taking advantage of Monte Carlo neutron transport codes, several configurations of ARC’s blanket and vacuum vessel have been analyzed in order to find the most effective one for a high TBR. The study takes into account different materials for the structure, such as Inconel718, V-15Cr-5Ti and Eurofer97. Moreover, it scans different width of coolant’s channels and evaluates the effect of lithium-6 enrichment in the blanket looking for the best configuration in terms of TBR.

Numerical study of obstacle geometry effect on the vortex shedding suppression and aerodynamic characteristics

Purpose Two-dimensional incompressible fluid flows around a rectangular shape placed over a larger rectangular shape at low Reynolds numbers (Re) have been numerically analyzed in the present work. The vortex shedding is investigated at different arrangements of the two shapes allowing the investigation of three possible configurations. The calculations are carried out for several values of Re ranging from 1 to 200. The effect of the obstacle geometry on the vortex shedding is analyzed for crawling, steady and unsteady regimes. The analysis of the flow evolution shows that with increasing Re beyond a certain critical value, the flow becomes unstable and undergoes a bifurcation. This paper aims to observe that the transition of the unsteady regime is performed by a Hopf bifurcation. The critical Re beyond which the flow becomes unsteady is determined for each configuration. A special attention is paid to compute the drag and lift forces acting on the rectangular shapes, which allowed determining; the best configuration in terms of both drag and lift. The unsteady periodic wake is characterized by the Strouhal number, which varies with the Re and the obstacle geometry. Hence, the values of vortex shedding frequencies are calculated in this work. Design/methodology/approach The dimensionless Navier–Stokes equations were numerically solved using the following numerical technique based on the finite volume method. The temporal discretization of the time derivative is performed by an Euler backward second-order implicit scheme. Non-linear terms are evaluated explicitly; while, viscous terms are treated implicitly. The strong velocity–pressure coupling present in the continuity and the momentum equations are handled by implementing the projection method. Findings The present paper aims to numerically study the effect of the obstacle geometry on the vortex shedding and on the drag and lift forces to analyze the flow structure around three configurations at crawling, steady and unsteady regimes. Originality/value A special attention is paid to compute the drag and lift forces acting on the rectangular shapes, which allowed determining; the best shapes configuration in terms of both drag and lift.

Continuously Frequency-Tunable Horn Filtennas Based on Dual-Post Resonators

This work reports the concept and development of two mechanically frequency-tunable horn filtennas for microwave and millimeter-waves. Our design approach relies on the integration of a horn antenna with a mechanically tunable filter based on dual-post resonators. The proposed filtennas have been manufactured and experimentally characterized, by means of reflection coefficient, radiation pattern, and gain. Measurements demonstrate that both filtennas have a tuning ratio of approximately 1.37 with continuous adjustment. The first prototype operates from 2.56 to 3.50 GHz, whereas in the second one the bandwidth is from 17.4 to 24.0 GHz. In addition, the higher-frequency filtenna has been implemented in a 5.0-meter-reach indoor environment, using a 16-QAM signal at 24 GHz. The best configuration in terms of performance resulted in a root mean square error vector magnitude (EVMRMS) and antenna radiation efficiency of 3.69% and 97.0%, respectively.

CFD studies on different configurations of drying chamber for thin-layer drying of leaves

ABSTRACT The design of a single air pass drying chamber used in tray dryers for thin-layer solar drying of fragile, heat-sensitive food materials such as edible leaves is a challenging task. It is essential to obtain good air distribution in all drying chamber designs to ensure uniform drying of the product. Simultaneous achievement of once-through air-side pressure drop and increase the moisture mass transfer rates are also important objectives of any heat and mass exchanger design. For obtaining these objectives in the dryer design, Computational fluid dynamics (CFD) is used as a tool for designing and theoretically testing different suitable air flow drying chamber configurations in the tray dryer. In this investigative research work, four different optimized geometries of the drying chamber for drying leaves are designed and evaluated theoretically from predicted performance by using ANSYS FLUENT software. The limiting air-side pressure drops and achieved dried output from various configurations are checked, assessed and presented in this work. The best configuration and construction detail are also highlighted. This generalized, proven, CFD procedure can be used for checking the performance of any similar transit type inter mass exchanger, to predict the best configuration in terms of mass transfer and pressure drop.