This work is a contribution to the development of flow sensors in the oil and gas industry. It presents a methodology to measure the flow rates into multiple-zone water-injection wells from fluid temperature profiles and estimate the measurement uncertainty. First, a method to iteratively calculate the zonal flow rates using the Ramey (exponential) model was described. Next, this model was linearized to perform an uncertainty analysis. Then, a computer program to calculate the injected flow rates from experimental temperature profiles was developed. In the experimental part, a fluid temperature profile from a dual-zone water-injection well located in the Northeast Brazilian region was collected. Thus, calculated and measured flow rates were compared. The results proved that linearization error is negligible for practical purposes and the relative uncertainty increases as the flow rate decreases. The calculated values from both the Ramey and linear models were very close to the measured flow rates, presenting a difference of only 4.58 m³/d and 2.38 m³/d, respectively. Finally, the measurement uncertainties from the Ramey and linear models were equal to 1.22% and 1.40% (for injection zone 1); 10.47% and 9.88% (for injection zone 2). Therefore, the methodology was successfully validated and all objectives of this work were achieved.
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http://dx.doi.org/10.3390/s16071077 | DOI Listing |
PLoS One
January 2025
School of Electronic Information Engineering, Inner Mongolia University, Hohhot, Inner Mongolia, China.
Cognitive Radio (CR) technology enables wireless devices to learn about their surrounding spectrum environment through sensing capabilities, thereby facilitating efficient spectrum utilization without interfering with the normal operation of licensed users. This study aims to enhance spectrum sensing in multi-user cooperative cognitive radio systems by leveraging a hybrid model that combines Convolutional Neural Networks (CNN) and Long Short-Term Memory (LSTM) networks. A novel multi-user cooperative spectrum sensing model is developed, utilizing CNN's local feature extraction capability and LSTM's advantage in handling sequential data to optimize sensing accuracy and efficiency.
View Article and Find Full Text PDFActa Neurochir (Wien)
January 2025
Department of Neurosurgery, The Fourth Affiliated Hospital of Soochow University, Suzhou, China.
Background: Superficial temporal artery (STA)-middle cerebral artery (MCA) side-to-side microvascular anastomosis can achieve the same clinical effects as traditional STA-MCA end-to-side anastomosis in extracranial-intracranial revascularization surgery, furthermore, STA-MCA side-to-side anastomosis has the lower risk of postoperative cerebral hyperperfusion syndrome (CHS) and the potential to recruit all scalp arteries as the donor sources via self-regulation. Therefore, STA-MCA side-to-side microvascular anastomosis seems to be a revascularization strategy superior to traditional STA-MCA end-to-side anastomosis. In this study, we presented seven cases in which a STA-MCA side-to-side microvascular anastomosis was performed with a 4-5 mm long arteriotomy using the in-situ intraluminal suturing technique.
View Article and Find Full Text PDFInt Endod J
January 2025
School of Medicine and Dentistry, Griffith University, Gold Coast, Australia.
Introduction: Biofilms may show varying adherence strengths to dentine. This study quantified the shear force required for the detachment of multispecies biofilm from the dentine using fluid dynamic gauging (FDG) and computation fluid dynamics (CFD). To date this force has not been quantified.
View Article and Find Full Text PDFMicrobiol Spectr
January 2025
Department of Biology and Chemistry, Changwon National University, Changwon, South Korea.
Unlabelled: Global aquaculture production faces the challenge of biologically cycling nitrogenous waste. Biofloc technology (BFT) systems offer the potential to reduce water consumption and eliminate waste products by using beneficial microorganisms to convert waste into usable nutrients or non-toxic molecules. Unlike flow-through systems (FTS), which depend on continuous water exchange and result in higher operational costs as well as limited microbiome stability, BFT operates without the need for constant water exchange.
View Article and Find Full Text PDFEnviron Sci Ecotechnol
January 2025
Systems Biotechnology Group, Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research - UFZ, 04318, Leipzig, Germany.
Biophotovoltaics (BPV) represents an innovative biohybrid technology that couples electrochemistry with oxygenic photosynthetic microbes to harness solar energy and convert it into electricity. Central to BPV systems is the ability of microbes to perform extracellular electron transfer (EET), utilizing an anode as an external electron sink. This process simultaneously serves as an electron sink and enhances the efficiency of water photolysis compared to conventional electrochemical water splitting.
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