A genetic algorithm for shortest path with real constraints in computer networks

The shortest path problem has many different versions. In this manuscript, we proposed a muti-constrained optimization method to find the shortest path in a computer network. In general, a genetic algorithm is one of the common heuristic algorithms. In this paper, we employed the genetic algorithm to find the solution of the shortest path multi-constrained problem. The proposed algorithm finds the best route for network packets with minimum total cost, delay, and hop count constrained with limited bandwidth. The new algorithm was implemented on four different capacity networks with random network parameters, the results showed that the shortest path under constraints can be found in a reasonable time. The experimental results showed that the algorithm always found the shortest path with minimal constraints

GEANT4 Simulation for Radioactive Particle Tracking (RPT) Technique

In the past two decades, the radioactive particle tracking (RPT) measurement technique has been proven to visualize flow fields of most multiphase flow systems of industrial interest. The accuracy of RPT, and hence the data obtained, depend largely on the calibration process, which stands here as a basis for two subsequent processes: tracking and reconstruction. However, limitations in the RPT calibration process can be found in different experimental constrains and in assumptions made in the classical Monte Carlo approach used to simulate number of counts received by the detectors. Therefore, in this work, we applied a GEANT4-based Monte Carlo code to simulate the RPT calibration process for an investigated multiphase flow system (i.e., gas–liquid bubble column). The GEANT4 code was performed to simulate the number of counts received by 28 scintillation detectors for 931 known tracer positions while capturing all the types of photon interaction and overcoming solids\u27 angle limitations in classical approaches. The results of the simulation were validated against experimental data obtained using an automated RPT calibration device. The results showed a good agreement between the simulated and experimental counts, where the maximum absolute average relative deviation detected was about 5%. The GEANT4 model typically predicted the number of counts received by all the detectors; however, it over-estimated the counts when the number of primary events applied in the model was not the optimal

Physicochemical characterization of natural hydroxyapatite/ cellulose composite

The natural hydroxyapatite (HAp, activated at different temperatures)/ cellulose composites have been prepared by usingsonication method to improve the physical properties of the cellulose fibre. The molecular level interaction and the physicalproperties of the hydroxyapatite/cellulose composite are examined using FTIR, X-ray diffraction, SEM, and thermalanalysis. The absorption bands at around 660 cm1 confirm the O–P–O bending vibration in the HAp/cellulose composites.There is a difference in the d-spacing of the HAp /cellulose composite, indicating that the HAp is reactive towards cellulose.SEM indicates that HAp could penetrate the cellulose network structure to form particles that is helpful to improve themechanical properties of the cellulose. The porosities of HAp/cellulose composites decrease, and their compressive strengthincrease as compared to those of cellulose. Thermogravimetric analysis confirms the highest thermal stability of theprepared composites

Patient perception and attitudes toward magnetic resonance imaging safety

BackgroundMagnetic resonance imaging (MRI) scanners use strong, static and fast magnetic fields to form images. Due to rapid developments in MRI technology, several accidents have been recorded in hospitals worldwide as a result of insufficient knowledge about the dangers of MRI on the part of the patient or a failure to follow safety guidelines. This study evaluates patients’ perception and attitudes about MRI safety.AimsThis is a cross sectional study to evaluate the perception and attitudes of patients regarding MRI safety procedures.MethodsA 21 items questionnaire was collected from 119 patients in the MRI waiting area before the commencement of examination. Data were analysed using Statistical Package for the Social Sciences (SPSS) software (version 22.0, IBM Corp, Armonk, New York). The odds (OR) and 95 per cent confidence interval (CI) were used for analysis, the level of significance was set at p=0.05 using Chi-Square test to evaluate the relationship among the variables in the questionnaire.ResultsThe responses were collected from the patients and their relatives (46 male (38.6 per cent) and 73 female (61.4 per cent)). Approximately 71 per cent of the participants have already read or heard about MRI and the related safety aspects. 76 per cent of overall participants stated that they are aware of the need for preparation before an MRI exam with more awareness of MRI safety issues among younger patients (88 per cent). In this instance, females showed a higher level of knowledge (26 per cent) compared to males (11 per cent) with p=0.035.ConclusionPatients reported insufficient information about MRI safety which may increase the potential for accidents

Decentralized community energy management: Enhancing demand response through smart contracts in a blockchain network

The integration of distributed energy resources (DERs) and digital technologies has accelerated the transition to decentralized energy systems. Among these technologies, blockchain stands out for its ability to facilitate peer-to-peer (P2P) energy trading efficiently and securely. This paper explores the concept of P2P energy trading within community microgrid systems, leveraging blockchain-based smart contracts. The proposed system integrates an incentive-driven demand response program directly into the smart contract framework, offering real-time rewards for load-balancing contributions. By incorporating the microgrid’s Energy Management System (EMS) and transparently recording all transactions on the blockchain, the proposed platform provides detailed data and immediate reward distribution. At the core of our system lies the Supply to Demand Ratio (SDR), ensuring fair energy exchange within the community. Dynamic pricing, enabled by blockchain and Tether (USDT) cryptocurrency, adjusts to real-time market conditions, enhancing transparency and responsiveness in energy trading. This adaptive pricing model fosters a more equitable and efficient trading environment compared to static approaches. Moreover, this system is tailored for community microgrids, emphasizing a community-centric approach. Local prosumers serve as validators in the blockchain network, aligning energy management decisions with community needs and dynamics. This localized engagement promotes efficiency and participation, fostering resilient, sustainable, and user-centric energy landscapes. Through rigorous analysis, we demonstrate the system’s effectiveness in optimizing economic efficiency, reducing operational costs, and increasing compliance rates. By combining blockchain technology with community-focused design principles, the proposed platform represents a significant advancement towards self-sufficiency and resilience in local energy systems

Imbalanced Prostanoid Release Mediates Cigarette Smoke-Induced Human Pulmonary Artery Cell Proliferation

BackgroundPulmonary hypertension is a common and serious complication of chronic obstructive pulmonary disease (COPD). Studies suggest that cigarette smoke can initiate pulmonary vascular remodelling by stimulating cell proliferation; however, the underlying cause, particularly the role of vasoactive prostanoids, is unclear. We hypothesize that cigarette smoke extract (CSE) can induce imbalanced vasoactive prostanoid release by differentially modulating the expression of respective synthase genes in human pulmonary artery smooth muscle cells (PASMCs) and endothelial cells (PAECs), thereby contributing to cell proliferation.MethodsAqueous CSE was prepared from 3R4F research-grade cigarettes. Human PASMCs and PAECs were treated with or without CSE. Quantitative real-time RT-PCR and Western blotting were used to analyse the mRNA and protein expression of vasoactive prostanoid syhthases. Prostanoid concentration in the medium was measured using ELISA kits. Cell proliferation was assessed using the cell proliferation reagent WST-1.ResultsWe demonstrated that CSE induced the expression of cyclooxygenase-2 (COX-2), the rate-limiting enzyme in prostanoid synthesis, in both cell types. In PASMCs, CSE reduced the downstream prostaglandin (PG) I synthase (PGIS) mRNA and protein expression and PGI2 production, whereas in PAECs, CSE downregulated PGIS mRNA expression, but PGIS protein was undetectable and CSE had no effect on PGI2 production. CSE increased thromboxane (TX) A synthase (TXAS) mRNA expression and TXA2 production, despite undetectable TXAS protein in both cell types. CSE also reduced microsomal PGE synthase-1 (mPGES-1) protein expression and PGE2 production in PASMCs, but increased PGE2 production despite unchanged mPGES-1 protein expression in PAECs. Furthermore, CSE stimulated proliferation of both cell types, which was significantly inhibited by the selective COX-2 inhibitor celecoxib, the PGI2 analogue beraprost and the TXA2 receptor antagonist daltroban.ConclusionsThese findings provide the first evidence that cigarette smoke can induce imbalanced prostanoid mediator release characterized by the reduced PGI2/TXA2 ratio and contribute to pulmonary vascular remodelling and suggest that TXA2 may represent a novel therapeutic target for pulmonary hypertension in COPD

Highly efficient GaN Doherty power amplifier for N78 sub-6 GHz band 5G applications

In this paper, a high-efficiency GaN Doherty power amplifier (DPA) for 5G applications in the N78 sub-6 GHz band is introduced. The theoretical analysis of the matching networks for the peak and carrier transistors is presented, with a focus on the impact of unequal power splitting for both transistors and the recommendation of a post-harmonic suppression network. The proposed design features an unequal Wilkinson power divider at the input and a post-harmonic suppression network at the output, both of which are crucial for achieving high efficiency. The Doherty power amplifier comprises two GaN 10 W HEMTs, measured across the 3.3 GHz to 3.8 GHz band (the N78 band), and the results reveal significant improvements in gain, output power, drain efficiency, and power-added efficiency. Specifically, the proposed design achieved a power gain of over 12 dB and 42 dBm saturated output power. It also achieved a drain efficiency of 80% at saturation and a power-added efficiency of 75.2%. Furthermore, the proposed harmonic suppression network effectively attenuated the harmonics at the output of the amplifier from the second to the fourth order to more than −50 dB, thus enhancing the device’s linearity