Search Results (7)

Many artificially intelligent systems solve complex health- and agriculture-related problems that require great computational power. Such systems are used for tracking medical records, genome sequence analysis, image-based plant disease detection, food supply chain traceability, and photosynthesis simulation. Massively parallel computers (MPCs) are among those used to solve these computation-intensive problems. MPCs comprise a million nodes; connecting such a large number of nodes is a daunting task. Therefore, hierarchical interconnection networks (HINs) have been introduced to solve this problem. A midimew-connected torus network (MTN) is a HIN that has basic modules (BM) as torus networks that are connected hierarchically by midimew links. This paper presents the performance of MTNs in terms of static topological parameters and cost-effectiveness, as measured through simulations. An MTN was compared with other networks, including mesh, torus, TESH, TTN, MMN, and TFBN. The results showed that our MTN had a low diameter with a high bisection width and arc connectivity. In addition, our MTN had a high cost–performance trade-off factor (CPTF), a high cost-effective factor (CEF), low packing density, and moderate message-traffic density with marginally higher costs, as compared to other networks, due to wire complexity. However, our MTN provided better bandwidth with higher static fault tolerance. Therefore, MTNs are suggested for further evaluation of the effective implementation of MPCs. Full article

There are many technologies to implement sand control in sand-prone wells, drilled in either weakly or nonconsolidated sandstones. Technologies that are used to prevent sanding can be divided into the following groups: screens (wire-wrapped screens, slotted liners, premium screens, and mesh screens), gravel packs, chemical consolidation, and technological ways (oriented perforation and bottomhole pressure limitation) of sanding prevention. Each particular technology in these groups has their own design and construction features. Today, slotted liners are the most well-studied technology in terms of design, however, this type of sand control screen is not always accessible, and some companies tend towards using wire-wrapped screens over slotted liners. This paper aims to study the design criteria of wire-wrapped screens and provides new data regarding the way in which wire design affects the sanding process. Wires with triangular (wedge), trapezoidal, and drop-shaped profiles were tested using prepack sand retention test methodology to measure the possible impact of wire profile on sand retention capabilities and other parameters of the sand control screen. It was concluded that a trapezoidal profile of wire has shown the best result both in terms of sand production (small amount of suspended particles in the effluent) and in particle size distribution in the effluent, that is, they are the smallest compared to other wire profiles. As for retained permeability, in the current series of experiments, high sand retention did not affect retained permeability, although it can be speculated that this is mostly due to the relatively high particle size distribution of the reservoir. Full article

Analyzing the combination of involving parameters impacting the efficiency of solar air heaters is an attractive research areas. In this study, cost-effective double-pass perforated glazed solar air heaters (SAHs) packed with wire mesh layers (DPGSAHM), and iron wools (DPGSAHI) were fabricated, tested and experimentally enhanced under different operating conditions. Forty-eight iron pieces of wool and fifteen steel wire mesh layers were located between the external plexiglass and internal glass, which is utilized as an absorber plate. The experimental outcomes show that the thermal efficiency enhances as the air mass flow rate increases for the range of 0.014–0.033 kg/s. The highest thermal efficiency gained by utilizing the hybrid optimized DPGSAHM and DPGSAHI was 94 and 97%, respectively. The exergy efficiency and temperature difference (∆T) indicated an inverse relationship with mass flow rate. When the DPGSAHM and DPGSAHI were optimized by the hybrid procedure and employing the Taguchi-artificial neural network, enhancements in the thermal efficiency by 1.25% and in exergy efficiency by 2.4% were delivered. The results show the average cost per kW (USD 0.028) of useful heat gained by the DPGSAHM and DPGSAHI to be relatively higher than some double-pass SAHs reported in the literature. Full article

In this study, an experimental outdoor investigation of the thermal efficiency and outlet air temperature was conducted on an unglazed, double-pass, solar air heater with a perforated absorber plate and packing wire mesh layers as a supplemental absorbent area. This was done to observe their effects on the thermal performance of the solar air heater. The double-pass collector was constructed with a bed height of 0.05 m, and a collection area of 1.5 m². The height of the upper channel was fixed at 0.015 m to improve the thermal efficiency, and the outlet temperature at air flow rates between 0.003 and 0.018 kg/s. The collector was mounted with a slope of 42° facing south, to maximize the intensity of solar irradiance during winter. The effects of the air flow rate, ambient temperature, inlet temperature, outlet temperature, and solar intensity were experimentally investigated. The results showed that thermal efficiency could be improved by increasing the air flow rate, where the highest thermal efficiency achieved was 86% at 0.018 kg/s. However, the temperature difference was increased to a maximum value of 38.6 °C, when the air flow rate was decreased to 0.003 kg/s. Furthermore, the results demonstrated a significant improvement in the thermal efficiency and outlet temperature; and when compared with previous research, the experimental results and the predictions for the outlet temperature using the theoretical model agreed. Full article

The influence of recycling on double-pass solar air collectors with welding of the V-corrugated absorber has been studied experimentally and theoretically. Welding the V-corrugated absorber and the recycle-effect concept to the solar air collector was proposed to strengthen the convective heat-transfer coefficient due to turbulence promotion. Both the recycle effect and the V-corrugated absorber can effectively enhance the heat transfer efficiency compared to various designs such as single-pass, flat-plate double-pass, and double-pass wire mesh packed devices. Recycling operations and welding the V-corrugated absorber could enhance the collector efficiency by increasing the recycle ratio, incident solar radiations, and air mass flow rates. The most efficient and economical operating conditions were found at R ≈ 0.5, with relatively small hydraulic dissipated energy compensation. It was found that the turbulence intensity increase from welding the V-corrugated absorber into the solar air collector channel could compensate for the power consumption increase, when considering economic feasibility. Full article

The improvement of device performance of a recycling solar air heater featuring a wire mesh packing was investigated experimentally and theoretically. The application of the wire mesh packing and recycle-effect concept to the present study were proposed aiming to strengthen the convective heat-transfer coefficient due to increased turbulence. Comparisons were made among different designs, including the single-pass, flat-plate double-pass and recycling double-pass wire mesh packed operations. The collector efficiency of the recycling double-pass wire mesh packed solar air heater was much higher than that of the other configurations for various recycle ratios and mass flow rates scenarios. The power consumption increment due to implementing wire mesh in solar air heaters was also discussed considering the economic feasibility. A fairly good agreement between theoretical predictions and experimental measurements was achieved with an analyzed error of 1.07%–9.32%. Full article

A new device for inserting an absorber plate to divide a flat-plate channel into two subchannels to conduct double-pass wire mesh packed operations was developed. The proposed wire mesh packed device improves the heat transfer efficiency substantially as compared that to flat-plate single-pass and double-pass operations using the same working dimensions, and the improvement of device performance was investigated experimentally and theoretically. Good agreement between the theoretical prediction and the measured values from the experimental results was achieved. Considerable heat transfer improvement was obtained employing wire mesh packed double-pass operations under the absorber plate with external recycle. The influences of recycle ratio on the heat transfer efficiency and the power consumption increase were also discussed. Full article