Literatura científica selecionada sobre o tema "Energy efficiency"

The solar photovoltaic (PV) system generates both electrical and thermal energy from solar radiation. In this paper, an attempt has been made for evaluating electrical output of solar PV panel installed at Ajat Instruments Nigeria Limited, Mokola, Ibadan, Nigeria. Using the first law of thermodynamics, energy/power analysis was performed. The operating and electrical parameters of a PV array include PV module temperature, open-circuit voltage, short-circuit current, fill factor, etc. were used. The reviewed formulas were used for the calculation of the energy/power efficiency of the PV system. Energy/power efficiency was calculated to be approximately 18%. Future studies should focus on modelling the efficiency of the solar panel. More investigation is required to define the optimum efficiency of the solar panel.

Each subsequent generation of wireless standards imposes stricter spectral and energy efficiency demands. So far, layered wireless transceiver architectures have been used, allowing for instance to separate channel decoding algorithms from the front-end design. Such an approach may need to be reconsidered in the upcoming 6G era. Especially hardware-originated distortions have to be taken into account while designing other layer algorithms, as high throughput and energy efficiency requirements will push these devices to their limits, revealing their non-linear characteristics. In such a context, this paper will shed some light on the new degrees of freedom enjoyed while cross-layer designing as well as controlling multicarrier and multiantenna transceivers in 6G systems.

Electricity storage devices play a very vital role in efficient energy management. Storage technologies vary depending on the specific needs and applications. Battery is a electric storage system which converts chemical energy into electrical energy and possess some specific parameters that characterize them. Here, four types of storage batteries are evaluated based on their efficiency, cost, life span and energy density properties using COPRAS and ARAS methods on Fermatean picture fuzzy sets. Firstly a decision matrix is constructed using Fermatean picture fuzzy sets and it is normalized. Entropy measure is defined which helps in calculation of weight values. Next aggregated weighted normalized Fermatean picture fuzzy matrix is found and using this relative significant and utility values are calculated in COPRAS method. In ARAS method optimal function values are determined and utility values are found. The alternatives are ranked based on the utility values. In both the methods it is found that the rank of the best alternative is the same whereas the ranking of other alternatives vary.

In old energy control system, there was no freedom for users to sale or purchase energy with their own choice and rate because system was centralized and also there were many issues such as electricity theft cases and losses and burden of these losses directly inculdded in public bills. Now after the introduction of blockchain these issues has been resolved such as the blockchain technology give freedom to user to sale or purchase energy according to the own rate with secure transaction system. The conventional energy system with centralizedcontrol technique fails to resolve many issues such as freedom to user’s to sale or purchase energy in network in secure way and combination of blockchain and Microgrid has all feature to resolve all present isssues. In this paper, the blockchain technology features and application of blockchain with clean energy system will be investigate to provide cheap electricity to users by using Microgrid because Blockchain provide complete solutions for energy distribution and trading. In addition, somemajor present issues will be focus such as low efficiency, losses and ant algorithm model to distribute the energy in the network efficiently.

This article presents the basic concepts of wind energy and deals with the physics and mechanics of operation. It describes the conversion of wind energy into the rotation of a turbine, and the critical parameters governing the efficiency of this conversion. After that it presents an overview of the various parts and component of windmills. The connection to the electrical grid, the world status of wind energy use for electricity production, the cost situation and research and development needs are further aspects which will be considered.

In all operating conditions, electrified sprinklers are provided with energy from a centralized source or a portable diesel generator. The energy efficiency of these power supply methods is characterized by losses of electricity during transmission. Battery power sources of sprinkler machines are used in rare cases, there are no such machines on the agricultural lands of the Volga region. If the battery power source is installed next to the electric drive on a support trolley, then there is no loss of electricity during transmission and there is the possibility of using renewable sources, the cost of electricity is close to zero. (Research purpose) The research purpose is in evaluating the increase in the energy efficiency of a sprinkler machine with a battery power source and renewable energy sources in comparison with traditional energy supply. (Materials and methods) Authors used theoretical and empirical methods of scientific knowledge, namely mathematical analysis, systematic approach, literature analysis, observation. (Results and discussion) The power consumption of irrigation systems fed the cable line from the centralized grid will consist of the energy consumed by the actuators support trucks irrigation systems and the energy consumed for transmission. The increase in the energy efficiency of a sprinkler machine with a battery power source in comparison with a cable line consists in saving energy for transmission. Found that when comparing the line cable from the battery feeding method should take into account the losses in transmission of energy along the entire length of the construction of irrigation machines and energy loss during transmission from the transformer substation to the fixed support irrigation systems. (Conclusions) The energy loss along the length of the sprinkler machine logarithmically depends on the number of sections. In relation to the operating conditions of sprinklers in the Saratov region, it is possible to reduce energy consumption even without taking into account the starting modes from 0.20 to 2.01 percent for water distribution by circular sprinklers.

Eurasian Journal of Physics and Functional Materials is an international journal published 4 numbers per year starting from October 2017. The aim of the journal is rapid publication of original articles and rewiews in the following areas: nuclear physics, high energy physics, radiation ecology, alternative energy (nuclear and hydrogen, photovoltaic, new energy sources, energy efficiency and energy saving, the energy sector impact on the environment), functional materials and related problems of high technologies.

The analysis of technologies and technical means of creating a temperature regime in the piglet location zone, where two different temperature fields must be created in the cold season: one for breeding pigs, the other for suckling piglets. The article considers the question of the use of thermoelectric modules and heat pipes as a source of thermal energy in local heating installations for suckling piglets. (Research purpose) There are proposed the functional and technological scheme of the installation for local heating of young animals with the use of thermoelectric modules and heat pipes. (Materials and methods) In the developed scheme, the thermal energy of the hot circuit of thermoelectric modules is used to heat the site on which the piglets are located. (Results and discussion) The heat of the cold circuit of the thermoelectric module assimilates the thermal energy of the removed ventilation air. For the effective operation of a thermoelectric installation for local heating of piglets, it is necessary that the cooling circuit, which absorbs thermal energy from the environment, be involved in some technological process for heat removal, for example, the heated ventilation air being removed. This leads to a significant increase in the efficiency of thermoelectric modules. At the same time, the installation will operate in the heat pump mode, since the amount of heat released in the heat exchanger of the hot circuit of the thermoelectric assembly exceeds the amount of electricity consumed from the network. (Conclusions) The article presents the sample of a thermoelectric installation was developed and its laboratory tests. The article describes the energy efficiency of the use of thermoelectric modules as energy converters in thermal technological processes.

Presents the results of the analysis of efficiency of application of the harmonized automatic control modes of operation of the burner and the drive boot the rotary kiln for firing of expanded clay. On the example of the furnace size of 40 m, in which fired raw clay smushlaevsks Deposit, the possibility to reduce energy consumption for production of 1 m 3 of expanded clay 11-to 15 %.

Les réseaux de capteurs visuels sans fil basés sur les réseaux maillés IEEE 802.11 sont des solutions efficaces et adaptées aux systèmes de vidéosurveillance pour surveiller les intrusions dans des zones sélectionnées. Les réseaux de capteurs visuels basés sur IEEE 802.11 offrent des transmissions vidéo à haut débit mais souffrent de problèmes d'inefficacité énergétique. De plus, la transmission vidéo dans les réseaux de capteurs visuels nécessite une qualité de service (QoS) stricte en termes de bande passante et de délai. En outre, il est difficile de réduire la consommation énergétique globale du réseau tout en garantissant une qualité de service garantie en termes de bande passante et de délai dans les réseaux de capteurs visuels sans fil à énergie limitée. La principale contribution de cette thèse est de fournir un réseau de vidéosurveillance économe en énergie sans compromettre l'exigence de qualité de service de la transmission vidéo. Premièrement, nous proposons une nouvelle architecture de réseau hybride IoT pour un système de vidéosurveillance qui détecte et suit un intrus dans la zone de surveillance. Le réseau IoT hybride intègre les réseaux de capteurs visuels multi-sauts basés sur IEEE 802.11 et le réseau LoRa pour fournir un système de vidéosurveillance autonome, économe en énergie et à haut débit. Tirant parti des caractéristiques du réseau LoRa, le réseau LoRa est utilisé comme un réseau toujours actif pour la détection et le suivi préliminaires des mouvements. De plus, le réseau LoRa décide également quels nœuds de capteurs visuels réveiller en fonction des informations de suivi. Le filtre de Kalman est étudié pour suivre la trajectoire de l'intrus à partir des mesures de bruit des capteurs de mouvement à faible puissance afin d'activer uniquement les nœuds de capteurs visuels le long de la trajectoire de l'intrus pour fournir une surveillance vidéo efficace. Nous avons montré par simulation que le filtre de Kalman estime et prédit la trajectoire de l'intrus avec une précision raisonnable. De plus, l'approche de réseau hybride IoT proposée réduit considérablement la consommation d'énergie par rapport à un réseau de capteurs visuels à un seul niveau de surveillance continue traditionnelle et toujours active. Ensuite, la contribution de cette thèse se concentre sur un mécanisme de routage sensible à l'énergie et QoS pour le réseau de capteurs visuels multi-sauts basé sur IEEE 802.11 du réseau hybride IoT. Nous proposons un algorithme de routage qui route un ensemble de flux vidéo vers la passerelle avec une QoS garantie en termes de bande passante et de délai tout en minimisant le nombre de nœuds capteurs visuels impliqués dans le routage. Cela maximise le nombre de nœuds pouvant être complètement désactivés pour optimiser la consommation énergétique globale du réseau sans compromettre les performances QoS. Le problème de routage proposé est formulé comme un programme linéaire entier (ILP) et résolu à l'aide d'un algorithme branch-and-bound. Grâce à la simulation informatique, les performances de l'approche proposée sont comparées aux algorithmes de routage de pointe existants dans la littérature. Les résultats montrent clairement que le mécanisme proposé permet d'économiser une quantité significative de la consommation d'énergie globale tout en garantissant la QoS en termes de bande passante et de délai
Wireless visual sensor networks based on IEEE 802.11 mesh networks are effective and suitable solutions for video surveillance systems in monitoring intrusions in selected areas. The IEEE 802.11-based visual sensor networks offer high bit rate video transmissions but suffer from energy inefficiency issues. Moreover, the video transmission in the visual sensor networks requires strict quality of service (QoS) in terms of bandwidth and delay. Also, it is challenging to decrease the overall energy consumption of the network while assuring guaranteed QoS in terms of bandwidth and delay in energy-constrained wireless visual sensor networks. The main contribution of this dissertation is to provide an energy-efficient video surveillance network without compromising the QoS requirement of video transmission. First, we propose a new hybrid IoT network architecture for a video surveillance system that detects and tracks an intruder in the monitoring area. The hybrid IoT network integrates the IEEE 802.11-based multi-hop visual Sensor Networks and LoRa network to provide an autonomous, energy-efficient, high-bitrate video surveillance system. Leveraging the LoRa network characteristics, the LoRa network is utilized as an always-active network for preliminary motion detection and tracking. Moreover, the LoRa network also decides which visual sensor nodes to wake up depending on the tracking information. The Kalman filter is investigated to track the intruder's trajectory from noise measurements of low-power motion sensors to activate only the visual sensor nodes along the intruder's trajectory to provide effective video vigilance. We showed through simulation that Kalman filter estimates and predicts intruder trajectory with reasonable accuracy. Moreover, the proposed hybrid IoT network approach reduces energy consumption significantly compared with a traditional, always active continuous monitoring single-tier visual sensor network. Next, the contribution of this dissertation focuses on an energy-aware and QoS routing mechanism for the IEEE 802.11-based multi-hop visual sensor network of the hybrid IoT network. We propose a routing algorithm that routes a set of video streams to the gateway with guaranteed QoS in terms of bandwidth and delay while minimizing the number of visual sensor nodes that are involved in routing. This maximizes the number of nodes that can be turned off completely to optimize the overall energy consumption of the network without compromising QoS performance. The proposed routing problem is formulated as an Integer Linear Program (ILP) and solved using the branch-and-bound algorithm. Through computer simulation, the performance of the proposed approach is compared with the existing state-of-the-art routing algorithms from the literature. The results clearly show that the proposed mechanism saves a significant amount of the overall energy consumption while guaranteeing QoS in terms of bandwidth and delay

Energy utilization and network life time are key issues in design of routing protocols for Wireless sensor network. Many algorithms have been proposed for reducing energy consumption and to increase network life time of the WSN. Clustering algorithms have gained popularity in this field, because of their approach in cluster head selection and data aggregation. LEACH (distributed) is the first clustering routing protocol which is proven to be better compared to other such algorithms. TL-LEACH is one of the descendants of LEACH that saves better the energy consumption by building a two-level hierarchy. It uses random rotation of local cluster base stations to better distribute the energy load among the sensors in the network especially when the density of network is higher. As the clusters are adaptive in LEACH and TL-LEACH, poor clustering set-up during a round will affect overall performance. However, using a central control scheme for cluster set-up may produce better clusters by distributing the cluster head nodes throughout the network. LEACH-C is another modification to LEACH that realizes the above idea and provides better results through uniform distribution of cluster heads avoiding redundant creation of cluster heads in a small area. In our project, we propose a centralized multilevel scheme called CML-LEACH for energy efficient clustering that assumes random distribution of sensor nodes which are not mobile. The proposed scheme merges the idea of multilevel hierarchy, with that of the central control algorithm providing uniform distribution of cluster heads throughout the network, better distribution of load among the sensors and improved packet aggregation. This scheme reduces energy consumption and prolongs network life time significantly as compared to LEACH, TL-LEACH and LEACH-C. The simulation results show comparisons of our scheme with the existing LEACH, TL-LEACH and LEACH-C protocols against chosen performance metrics, using Omnet++.

In today's world power management plays a very significant role in reducing the power consumption and the efficient utilization of the available resources. In the traditional system, due to the manual operation of the different electrical appliances in the university gets un-attended, and that leads to the maximum wastage of the resources such that the different appliances operating during off-peak hours without any need or requirement and also the street lights remains burning with full intensity during off-peak hours and zero traffic hours. In order to overcome this problem, we we have designed a "smart and energy efficient power saving system", where every rooms as well as every devices are equipped with passive infrared sensor (PIR) which responds the occupancy, and correspondingly devices are controlled automatically. All the street lights are controlled using real time clock (RTC), and the studies astronomical data from Indian Meterological Department and the traffic is detected using the laser according to which the street lights burns with full intensity during peaks hours and with reduces intensity during off-peak hours. Also, a traffic based switching is incorporated for efficient utilization of resources during off-peak hours. There is a secure wireless data transmission methodology used for data transmission from sink to the base station. The entire system is monitored and controlled by the central base station

We present the results of the numerical simulations of the collapse of magnetic rotating protostellar clouds with mass 10M ⊙ . The hierarchical structure of the cloud formed at the isothermal stage of the collapse is investigated for various initialratios of the magnetic energy of the cloud to the modulus of its gravitational energy, ε m . It is shown that the size of thequasi-magnetostatic primary disk and the region of efficient magnetic braking increase with ε m . In the case ε m ≥ 0.6,practically the entire cloud evolves into the state of quasi-magnetostatic equilibrium. A ‘dead’ zone forms inside the firsthydrostatic core and in the area of the outflow formation, where Ohmic dissipation and ambipolar diffusion become essential.

Abstract Pipeline corrosion poses significant challenges and risks to the energy industry and its mitigation requires extensive and reliable predictive modeling. Corrosion models based on computational fluid dynamics (CFD) stands as a desirable candidate for its detailed physical characterization and modeling flexibility, but its applications in practical industrial settings is limited by the high computational cost and laborious manual operation in the modeling and sampling process. To address these challenges, we propose a Bayesian active learning method. The method consists of a surrogate model formulated using Gaussian process regression (GPR) to provide rapid model prediction as well as uncertainty quantification, and an adaptive sampling scheme to automate and accelerate the data collection process. Careful dimension reduction guided by both physics and data is also carried out to significantly simplify the sampling space. The capability of the overall method for efficient and automated sampling and surrogate modeling is demonstrated on an example case of corrosion predictive modeling and can be leveraged in industrial applications at a much larger scale.