Search

This paper presents a Hybrid Renewable Energy system combining multiple sources of renewable energy, such as PV, Wind, and energy storage devices, to provide a reliable and sustainable power supply. Cascaded converters are used to efficiently transform and manage the energy from these sources. To achieve optimal performance and reliable operation, a real-time closed-loop control algorithm is designed and implemented for the cascaded converter. The control algorithm facilitates the smooth integration of energy from various renewable sources, optimizing the utilization of available resources and ensuring a consistent power supply. The algorithm maximizes the energy conversion efficiency of the cascaded converter, reducing energy losses and minimizing waste. It also optimizes the integration of renewable sources, regulates output parameters, and ensures efficient energy conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • A close-loop recycling method using both reusable leaching and extracting reagents. • UV–VIS is proven to be an efficient method for the Co quantification in the DES. • Alginate hydrogels can extract over 90% of the cobalt from the leachate. • Alginate hydrogels were reused with a performance of ca. 90% that of pristine ones. • The DES was reused with a performance ca. 90% that of the pristine DES. With the aim of achieving carbon neutrality, new policies to promote electric vehicle (EV) deployment have been announced in various countries. As EV sales gain market-share, the demand for batteries is growing very rapidly, and this has raised concerns about the raw-material supply. Therefore, efficient and environmentally friendly recycling methods for lithium-ion batteries (LIBs) are mandatory to properly implement circular economy paradigms in this field. Hydrometallurgical recycling methods are characterized by their selectivity, high product purity as well as low energy consumption. In order to accomplish a close-loop recycling method, in this work we propose the use of a deep eutectic solvent (DES) and alginate hydrogels as leaching reagent and adsorbent, respectively, for their reusability, availability and biodegradability. The solubility and thermal stability of a choline chloride-ethylene glycol based DES (choline chloride: ethylene glycol = 1:2) were investigated, 180 °C being regarded as the temperature threshold for this DES, and reaching up to 1.12 g Co L−1 solubility after 8 h leaching. Moreover, the DES can be reused after the eutectic state recreation with a performance over 80 % with respect to the pristine DES. Calcium cross-linked sodium alginate hydrogels, which were immersed in ethylene glycol and dehydrated afterwards, were able to extract cobalt from the leachate with an efficiency of 92 %. The aforementioned hydrogels can be reused after desorption and reach 91 % of the performance of the pristine ones. The DES together with alginate hydrogel brings therefore a highly efficient and reusable close-loop recycling method. [ABSTRACT FROM AUTHOR]

This paper presents preliminary study on multi-layer deposition of aerospace grade Al 6061 alloy by novel friction stir powder additive manufacturing process. Minimum temperature of deposition was in-situ maintained using close loop temperature-controlled system for minimizing thermal gradient in the build direction. Maximum temperature during the deposition was monitored in-situ using pyrometer and thermal imaging camera. Use of a tool with circumferential and radial grooves and continuous external heating facilitated smooth three-layer deposition of Al 6061 alloy with 60% deposition efficiency and 417°C as maximum deposition temperature. Larger value of temperature at deposition zone improved material flowability and deposition quality. Microstructure of multi-layer deposition found to consist of fine sub-grains. Element analysis showed uniform distribution of major alloying elements in it. Phase analysis revealed Al along with Mg2Si hardening precipitates. Tensile strength and microhardness were close to the commercially available wrought AA6061-T4 alloy. It showed ductility with 16% elongation. The presented process is a viable alternative to fusion-based additive manufacturing processes for multi-layer depositions of aerospace grade and other lightweight alloys which are difficult-to-additively-manufacture.

Closed-loop systems have been designed to assist anesthetists in controlling anesthetic drugs and also maintaining the stability of various physiological variables in the normal range. In the present study, we describe and clinically evaluated a novel closed-loop automated blood pressure control system (CLAPS) in patients undergoing cardiac surgery under cardiopulmonary bypass. Forty ASA II–IV adult patients undergoing elective cardiac surgery were randomly allocated to receive adrenaline, noradrenaline, phenylephrine and nitroglycerine (NTG) adjusted either through CLAPS (CLAPS group) or manually (Manual group). The desired target mean arterial blood pressure (MAP) for each patient in both groups was set by the attending anesthesiologist. The hemodynamic performance was assessed based on the percentage duration of time the MAP remained within 20% of the set target. Automated controller performances were compared using performance error criteria of Varvel (MDPE, MDAPE, Wobble) and Global Score. MAP was maintained a significantly longer proportion of time within 20% of the target in the CLAPS group (79.4% vs. 65.5% p < 0.001, 't' test) as compared to the manual group. Median absolute performance error, wobble, and Global score was significantly lower in the CLAPS group. Hemodynamic stability was achieved with a significantly lower dose of Phenyepherine in the CLAPS group (1870 μg vs. 5400 μg, p < 0.05, 't' test). The dose of NTG was significantly higher in the CLAPS group (3070 μg vs. 1600 μg, p-value < 0.05, 't' test). The cardiac index and left ventricular end-diastolic area were comparable between the groups. Automated infusion of vasoactive drugs using CLAPS is feasible and also better than manual control for controlling hemodynamics during cardiac surgery. Trial registration number and date This trial was registered in the Clinical Trial Registry of India under Registration Number CTRI/2018/01/011487 (Retrospective; registration date; January 23, 2018). [ABSTRACT FROM AUTHOR]

Congestion, and how to manage it or prevent its occurrence, is one of the most crucial and cutting-edge subjects in the world of networks since it has a significant influence on the computer network and the quality of service (QoS). Network efficiency is decreased by congestion, which frequently results in service interruptions. In order to preserve the continuity of data flow in the network, it is necessary to design approaches and processes to avoid congestion or to minimize its effects. Congestion are avoided at two levels, knot and link, by using different techniques, including close loop or open loop. This paper proposed a new technique (TLBCA) to distribute packets arriving at a specific node on the links connected to it, which leads to the same destination, to avoid congestion on one of the links and out of service, which then leads to more load on the other links until the network collapses. TLBCA is based on the popular algorithm Round Robin. ECMP and TinyFlow, the two most widely used comparable algorithms in this sector, performed around 20% worse than the approach when it was simulated using OMNET++. [ABSTRACT FROM AUTHOR]

Sinkronisasi merupakan salah satu cara untuk mendapatkan energi listrik yang besar dari generator dengan cara memparalelkannya. Adapun syarat dari sinkronisasi generator adalah nilai frekuensi, sudut fasa, urutan fasa-fasa dan tegangan sama. untuk sinkronisasi ini digunakan dua buah generator yangmana generator 1 (utama) dianggap sebagai set point yang akan disesuaikan oleh generator 2 (parallel) untuk menyamakan nilai syarat sinkronisasi. dalam penyamaan tegangan, digunakan metode boost converter yang merupakan jenis DC-DC converter yang menaikkan tegangan DC melalui pengaturan PWM. Untuk sistem kendalinya, kontroller akan menampilkan nilai syarat generator 2 (paralel) dengan generator 1(utama). Untuk sudut fasa, alat akan menyesuaikan otomatis dengan cara mengulang penghidupan generator dengan kendali close loop hingga di dapatkan nilai sudut fasa yang sama. Saat nilai syarat sinkronisasi kedua generator sama, kontroller akan mengaktifkan kontaktor sehingga terjadi sinkronisasi generator.

Privatization has led to the formation dynamic competition in markets, such as airline service providers with a limited number of suppliers and a large number of customers (oligopoly markets). Suppliers of goods and services in these markets are considering the behavior of competitors to determine the amount of products and advertisements in order to maximize their benefits. This paper investigates a differential oligopoly game model under open loop and close loop structures. By applying mathematical validation of the optimal levels of production (supply) and advertising cost, the proposed model used to analyze the market for airline services, and it is shown that parameters such as sticky price, substitutability among goods and advertising promotional efficiency on supply and advertising are effective in achieving sustainable equilibrium in such markets. Sensitivity analysis of the parameters in the proposed model shows that in open loop strategy when companies in an oligopoly market do not agree any agreement in all stages of competition, they will suffer a lot of financial burden.

This paper presented the design, simulation, and implantation a DC-DC step-up Flyback converter that regulates the output voltage to give the desired value 200 V 100 W and can be used in many application such as power supply. To give a regulated output voltage from the flyback converter, a feedback loop with Proportional-integral (PI) controller is used. A simulation of the flyback converter employed by MATLAB/Simulink under variation in the input voltage and load. Also, the practical implementation used Arduino Uno microcontroller to control the duty cycle through IR2110 driver at the change in the input voltage or resistive load. It gives better flexibility and a good response to the control system. The duty controller to create regulate output voltage by using voltage control mode.

Electrical parameter such as charging voltage and time series of discharge in repetition-frequency pulse power supply (RFPPS) can be adjusted. In order to obtain the accuracy of launch time and enough muzzle energy, constant current charging technology is taken, which can make RFPPS charge linear and the discharge time same in each discharge cycle. In this paper, the influence factors of accuracy are analyzed. It is proposed to control the accuracy of the charging time by means of the closed-loop feedback of the average charging current. A simulation and experiment of RFPPS test system are established. The results of simulation and experiment show that the charging time is proportional to the charging voltage after pulse-frequency modulation. The launch time can be determined by the charging voltage. Through this way, incoming target will be intercepted if the interception distance and the launching velocity are measured and calculated accurately. [ABSTRACT FROM PUBLISHER]

Present medical practice encourages management according to written guidelines, protocols, and structured procedures (GPPs). Daily medical practice includes instances in which "leaping" from one patient management routine to another is a must. We define "frozen patient management", when patient management leaping was required but was not performed. Frozen patient management may cause significant damage to patient safety and health and the treatment quality. This paper discusses the advantages and disadvantages of GPP-guided medical practice and gives an explanation of the problem of frozen patient management in light of quality engineering, control engineering, and learning processes. Our analysis of frozen patient management is based on consideration of medical care as a process. By considering medical care processes as a closed-loop control process, it is possible to explain why, when an indication for deviation from the expected occurs, it does not necessarily attract the medical teams' attention, thereby preventing the realization that leaping to an alternative patient management is needed. We suggest that working according to GPPs intensifies the frozen patient management problem since working according to GPPs relates to "exploitation learning behavior", while leaping to new patient management relates to "exploration learning behavior". We indicate practice routines to be incorporated into GPP-guided medical care, to reduce frozen patient management. [ABSTRACT FROM AUTHOR]