This paper presents a new high voltage gain DC–DC converter for renewable energy applications without the need for a galvanic isolation. The converter combines the active switched‐inductor network and the switched‐capacitor network to boost the voltage gain ratio without a high duty ratio. The presented converter uses clamping capacitors to minimize the maximum voltage stress of the power‐switching devices; hence, low power rating devices can be employed. Furthermore, the converter operates at a high switching frequency. Therefore, the use of small inductors and capacitors is the main advantage. The paper describes in detail the operating mode and design procedures of the converter. Additionally, the associated power losses and the efficiency are calculated. A 200‐W laboratory prototype was fabricated, and experimental results verified the theoretical analysis.

The research proposes a new oppositional sine cosine muted differential evolution algorithm (O-SCMDEA) for the optimal allocation of distributed generators (OADG) in active power distribution networks. The suggested approach employs a hybridization of the classic differential evolution algorithm and the sine cosine algorithm in order to incorporate the exploitation and exploration capabilities of the differential evolution algorithm and the sine cosine algorithm, respectively. Further, the convergence speed of the proposed algorithm is accelerated through the judicious application of opposition-based learning. The OADG is solved by considering three separate mono-objectives (real power loss minimization, voltage deviation improvement and maximization of the voltage stability index) and a multi-objective framework combining the above three. OADG is also addressed for DGs operating at the unity power factor and lagging power factor while meeting the pragmatic operational requirements of the system. The suggested algorithm for multiple DG allocation is evaluated using a small test distribution network (33 bus) and two bigger test distribution networks (118 bus and 136 bus). The results are also compared to recent state-of-the-art metaheuristic techniques, demonstrating the superiority of the proposed method for solving OADG, particularly for large-scale distribution networks. Statistical analysis is also performed to showcase the genuineness and robustness of the obtained results. A post hoc analysis using Friedman–ANOVA and Wilcoxon signed-rank tests reveals that the results are of statistical significance.

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BackgroundIntracranial arteriovenous malformation (AVM) is a rare congenital disease that is characterized by an abnormal tangle of blood vessels where arteries abnormally shunt into veins with no intervening capillary bed. Several treatment modalities, such as microsurgical removal, embolization, and stereotactic radiosurgery (SRS), are used to treat AVM either solely or in combination. We aimed to assess and compare the effect, morbidity, and mortality outcomes of mono-treatment with embolization and combined treatment for AVM obliteration. MethodologyThis retrospective cohort study was conducted in the National Guard Hospital Jeddah and reviewed all the AVM patients that visited the center between 2008 and 2017. We assessed presenting symptoms at diagnosis and any co-morbidities as the clinical characteristics and the patients' AVM and Spetzler-Martin grade as the morphological characteristics. Moreover, we performed a three-year follow-up on suitable patients and assessed their outcomes using the modified Rankin Scale. In addition, we performed follow-up imaging on the patients to evaluate AVM obliteration after any of the procedures. ResultsWe included 29 patients treated in our hospital (72.4%, males; 27.6%, females; mean age 40 years). About 65% of the patients underwent mono-therapy consisting of one or more embolization sessions while about 34% underwent combined treatment (embolization + surgery or embolization + SRS). We found more cases of complete obliteration among patients who underwent mono-therapy (52.6%) than among those who underwent combined treatment (30%). Patients who underwent mono-therapy showed better outcomes compared to those who underwent combined therapy; however, the difference did not reach statistical significance. ConclusionsEmbolization mono-therapy appears to be more effective with regards to the obliteration rate and outcome compared to combined therapy with either SRS or surgery in patients treated in our center.

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