Energy Conservation Features Research Articles

Dissipation in Onsager’s Critical Classes and Energy Conservation in BV∩L∞\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$BV\\cap L^\\infty $$\\end{document} with and Without Boundary

This paper is concerned with the incompressible Euler equations. In Onsager’s critical classes we provide explicit formulas for the Duchon–Robert measure in terms of the regularization kernel and a family of vector-valued measures {μz}z⊂Mx,t\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\{\\mu _z\\}_z\\subset {\\mathcal {M}}_{x,t}$$\\end{document}, having some Hölder regularity with respect to the direction z∈B1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$z\\in B_1$$\\end{document}. Then, we prove energy conservation for Lx,t∞∩Lt1BVx\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$L^\\infty _{x,t}\\cap L^1_t BV_x$$\\end{document} solutions, in both the absence or presence of a physical boundary. This result generalises the previously known case of Vortex Sheets, showing that energy conservation follows from the structure of L∞∩BV\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$L^\\infty \\cap BV$$\\end{document} incompressible vector fields rather than the flow having “organized singularities”. The interior energy conservation features the use of Ambrosio’s anisotropic optimization of the convolution kernel and it differs from the usual energy conservation arguments by heavily relying on the incompressibility of the vector field. This is the first energy conservation proof, for a given class of solutions, which fails to simultaneously apply to both compressible and incompressible models, coherently with compressible shocks having non-trivial entropy production. To run the boundary analysis we introduce a notion of “normal Lebesgue trace” for general vector fields, very reminiscent of the one for BV functions. We show that having such a null normal trace is basically equivalent to have vanishing boundary energy flux. This goes beyond the previous approaches, laying down a setup which applies to every Lipschitz bounded domain. Allowing any Lipschitz boundary introduces several technicalities to the proof, with a quite geometrical/measure-theoretical flavour.

Rotating Shallow Water Flow Under Location Uncertainty With a Structure‐Preserving Discretization

AbstractWe introduce a physically relevant stochastic representation of the rotating shallow water equations. The derivation relies mainly on a stochastic transport principle and on a decomposition of the fluid flow into a large‐scale component and a noise term that models the unresolved flow components. As for the classical (deterministic) system, this scheme, referred to as modeling under location uncertainty (LU), conserves the global energy of any realization and provides the possibility to generate an ensemble of physically relevant random simulations with a good trade‐off between the model error representation and the ensemble's spread. To maintain numerically the energy conservation feature, we combine an energy (in space) preserving discretization of the underlying deterministic model with approximations of the stochastic terms that are based on standard finite volume/difference operators. The LU derivation, built from the very same conservation principles as the usual geophysical models, together with the numerical scheme proposed can be directly used in existing dynamical cores of global numerical weather prediction models. The capabilities of the proposed framework is demonstrated for an inviscid test case on the f‐plane and for a barotropically unstable jet on the sphere.

A Linearised θ Numerical Scheme for the Vibrations of Inextensible Beams

A linearised finite element numerical scheme for the vibration of inextensible beams is developed. The proposed scheme is based on the methodology introduced by S. Bartels [15] and satisfies a linearised form of the inextensibility constraint. The time m arching procedure is based on repeated use of the theta-parameter integration quadrature. Three parameters are introduced in total and appropriately selected such that the energy conservation features are improved compared to the Bartels algorithm while the inextensibility constraint is satisfied as accurately as possible. Cubic Hermite polynomials are employed for the spatial discretisation. The Bartels algorithm is retrieved as a special case. Several numerical experiments are presented demonstrating the theoretically predicted enhanced inextensibility mimicking and optimum values of the method parameters are identified.

Multi‐Functional Metasurface: Visibly and RF Transparent, NIR Control and Low Thermal Emissivity

AbstractRapid advances in metamaterial technology are enabling the engineering of wave–matter interactions heretofore not realized and functionalities with potentially far‐reaching implications for major challenges in the fields of energy conservation and radio frequency (RF) communication. A visibly and RF transparent composite metasurface utilizing dielectric–metal spectrally selective coatings with high near‐infrared control and low thermal emissivity is proposed, thus achieving a multi‐functional metasurface capable of enhancing fifth‐generation (5G) communication efficiency and exhibiting energy conservation features. The proposed meta‐glass yields 92% peak RF transmission at 30 GHz which corresponds to 20% and 90% enhancement when compared to plain glass and low‐emissive glass substrates. This meta‐glass possesses 86% peak optical transparency at λ = 550 nm, >60% near‐infrared reflection, and >80% mid‐infrared reflection which corresponds to ≈0.2 thermal emissivity. The proposed metasurface design is highly flexible and can be tuned to operate over different frequency ranges owing to its frequency scalability. This study provides a better alternative using earth‐abundant materials compared to low‐emissive glass based on indium tin oxide while boosting the efficiency of 5G communication amenable to window systems demanding simultaneous functionalities for emergent smart/energy‐efficient buildings/cities and autonomous transportation applications.

QoS-Aware VNF Placement and Service Chaining for IoT Applications in Multi-Tier Mobile Edge Networks

Mobile edge computing and network function virtualization (NFV) paradigms enable new flexibility and possibilities of the deployment of extreme low-latency services for Internet-of-Things (IoT) applications within the proximity of their users. However, this poses great challenges to find optimal placements of virtualized network functions (VNFs) for data processing requests of IoT applications in a multi-tier cloud network, which consists of many small- or medium-scale servers, clusters, or cloudlets deployed within the proximity of IoT nodes and a few large-scale remote data centers with abundant computing and storage resources. In particular, it is challenging to jointly consider VNF instance placement and routing traffic path planning for user requests, as they are not only delay sensitive but also resource hungry. In this article, we consider admissions of NFV-enabled requests of IoT applications in a multi-tier cloud network, where users request network services by issuing service requests with service chain requirements, and the service chain enforces the data traffic of the request to pass through the VNFs in the chain one by one until it reaches its destination. To this end, we first formulate the throughput maximization problem with the aim to maximize the system throughput. We then propose an integer linear program solution if the problem size is small; otherwise, we devise an efficient heuristic that jointly takes into account VNF placements to both cloudlets and data centers and routing path finding for each request. For a special case of the problem with a set of service chains, we propose an approximation algorithm with a provable approximation ratio. Next, we also devise efficient learning-based heuristics for VNF provisioning for IoT applications by incorporating the mobility and energy conservation features of IoT devices. We finally evaluate the performance of the proposed algorithms by simulations. The simulation results show that the performance of the proposed algorithms is promising.

60 GHz Millimeter-wave Bottom-Layer Solutions: Multiplexing Access, Energy Awareness, and Peak-to-Average-Power Ratio

A clear trend shows that cells are smaller, more homogeneously distributed, higher frequency oriented, and more energy conscious. This points toward wireless systems that implement millimeter-wave modulation; therefore, improving its usability is essential for the communication systems evolution. The proposed bottom-layer solutions are (1) a variable slot time multiplexing access technique with an energy-conservation feature that supports self-sustainability, and (2) SC-FDMA as the technology implemented at the physical layer to minimize the peak-to-average-power ratio (PAPR) of the system. It is shown that the multiplexing protocol has advantages over TDMA, self-sustainability is feasible, and SC-FDMA reduces the PAPR of the modulated signal.

The Research on Energy-Saving Strategy of WSN in 220KV Substation

Aiming at the power problem of the wireless sensor network system in a 220KV substation, research about energy-saving control strategy in wireless monitoring system was described from the design of the microcontroller high-speed working mode and an optimization of RF module starting sequence. In the end, a wireless temperature measurement platform including three wireless senor nodes and a gateway node was realized. Results from the experiment make clear that the presented research strategy was provided with favorable energy conservation feature and can be suitable for wireless sensor network system in a 220KV substation.

Hybrid PID and PSO-based control for electric power assist steering system for electric vehicle

Electric power assist steering (EPAS) system provides an important significance in enhancing the driving performance of a vehicle with its energy-conserving features. This paper presents a hybrid PID (Proportional-Integral-Derivative) and particle swarm optimization (PSO) based control scheme to minimize energy consumption for EPAS. This single objective optimization scheme is realized using the PSO technique in searching for best gain parameters of the PID controller. The fast tuning feature of this optimum PID controller produced high-quality solutions. Simulation results show the performance and effectiveness of the hybrid PSO-PID based controller as opposed to the conventional PID controller.

A study of water use and water conservation policies at (primary) eco-schools in istanbul

As in all building types, water conservation is important in various ways in primary education buildings that see intensive use. In addition to environmental and economic benefi ts, systematic application of sustainable water management in elementary education buildings also makes a positive contribution to the education of future generations. The ‘Eco-Schools International Programme’, which is an organization established for achieving these goals, was established in 1994 with European Union support. The programme aims to introduce environmental management systems into primary schools within the scope of ISO 14001/EMAS. It has a crucial task of educating new generations and sustainable development throughout the world. All the previous studies conducted on eco-schools indicate that they are healthier places to learn and work, they have minimal negative impact on the environment and they have lower operating costs compared to conventional schools. This study examines elementary schools in Istanbul, which are part of the Eco-Schools International Programme. A questionnaire study was administered on the theme of water management within elementary schools located in the Asian and European parts of Istanbul city, and the fi ndings of a fi eld survey were examined. Questionnaire fi ndings were gathered according to these headings under two main categories: water use and water conservation policies at outdoor environments of eco-schools (landscape water conservation measures at eco-schools, irrigation technology and irrigation timing and frequency) and water use and water conservation policies at indoor environments of the eco-schools (types of water conservative components and equipments, hot water, water and energy conservation features (eco-label) of electrical appliances and maintenance of water-related equipment). According to these topics of questionnaire study, eco-schools at Istanbul often exhibit a successful performance in terms of water conservation policies. However insuffi cient use of collected rainwater, treated wastewater and advanced and environmentally friendly irrigation technologies at outdoor environments of eco-schools have been observed. Similarly, it has been observed that usage of different technological enhancements towards conservative wares usage like hand-basin taps of the push-on or self-stopping types are used at a very low rate at indoor environments of the eco-schools.

A Novel Power Supply for High Speed Drilling Electrical Discharge Machining Base on Pulsed Width Modulated

In this paper, a novel Pulsed-Width-Modulated (PWM) half-bridge High Speed Drilling Electrical Discharge Machining (HSDEDM) power supply has been developed. This power supply has excellent features that include minimal component count and inherent protection. This topology has an energy conservation feature and eliminates the output bulk capacitors and current limiting resistances. Energy used in the erosion process will be controlled by the switched Insulated Gate Bipolar Transistors (IGBTs) in the half-bridge network and be transferred to the gap between the tool and work-piece. The relative tool wear and machining speed of our proposed topology have been compared with that of a normal power supply with current limiting resistances.

WEEC 2008 Energy Management Systems Pushing Your Energy Management System to the Limit

ABSTRACT Our planet is in the midst of an energy crisis. Our traditional energy resources (oil, gas, coal) are limited. Due to ever-increasing competition for the finite supply of traditional energy sources, costs continue to escalate. The first step to combat rising energy costs is to make the most efficient use of what you have. This article summarizes several strategies to reduce energy costs by fully utilizing energy management system (EMS) features available with current building automation systems. Experience has shown that many facilities do not fully exploit the potential energy conservation tools at their disposal. The typical site energy management strategy does little more than time-of-day scheduling. There are numerous energy conservation measures that can be employed to reduce energy consumption—EMS strategies (utilizing all energy conservation features), continuous commissioning, and measurement and verification, to name a few. Designers must look for opportunities to fully specify all the energy conservation capabilities in an EMS. Building energy managers must be educated on building systems, look for energy conservation opportunities and utilize all the features of the EMS to help drive down energy costs. Additionally as more EMS features are utilized, the energy benefits increase. The incremental cost of additional energy features is typically low which helps the financial performance of the project. To ensure EMS features get utilized in new buildings, the designer must specify in detail which features are required and the expectations. Simply stating “the system must be capable of” does not mean that the EMS feature will be used. The training should be specific to the EMS and detailed enough to properly educate the users. Building energy managers must dedicate time to understand how to use the EMS and all of its functionality. Without the proper training and education, the building energy manager may not recognize energy conservation opportunities (ECOs). This knowledge is essential to developing a site energy management strategy. When a building manager pushes the EMS to the limit, the end result is lower operating costs, increased occupant comfort, and lower maintenance costs due to planned maintenance rather than emergency maintenance.

A Novel Half-Bridge Power Supply for High Speed Drilling Electrical Discharge Machining

High Speed Drilling Electrical Discharge Machining (HSDEDM) uses controlled electric sparks to erode the metal in a work-piece. Through the years, HSDEDM process has widely been used in high speed drilling and in manufacturing large aspect ratio holes for hard-to-machine material. The power supplies of HSDEDM providing high power applica-tions can have different topologies. In this paper, a novel Pulsed-Width-Modulated (PWM) half-bridge HSDEDM power supply that achieves Zero-Voltage-Switching (ZVS) for switches and Zero-Current-Switching (ZCS) for the dis-charge gap has been developed. This power supply has excellent features that include minimal component count and inherent protection under short circuit conditions. This topology has an energy conservation feature and removes the need for output bulk capacitors and resistances. Energy used in the erosion process will be controlled by the switched IGBTs in the half-bridge network and be transferred to the gap between the tool and work-piece. The relative tool wear and machining speed of our proposed topology have been compared with that of a normal power supply with current limiting resistances.

95/03800 Stratton House: Combining active and passive solar energy conservation features

95/03800 Stratton House: Combining active and passive solar energy conservation features

A Research Note on: Consumer Preferences for Selected Energy Conservation Features in Housing

AbstractThis paper examines preferences of Utah residents for energy conservation strategies for space heating. The results are based on data collected in 1981 and 1983 by a mail survey of Utah residents. In both surveys, energy conservation features were found to be Important considerations in choosing a dwelling. In particular, more than 70 percent of the respondents reported they would be more likely or much more likely to buy a house that has solar heating. The acceptance of solar heating is broad-based, with no significant differences with respect to location, age, sex, income or education of respondent. Nearly two-thirds of the respondents indicate that the presence of a wood-burning stove would favorably affect their housing choice. Younger respondents and those located in rural areas were the most likely to prefer a wood-burning stove. The impact of conservation features on house selection preferences diminished from 1981 to 1983, but, with the exception of solar heating, the changes are not stati...

A Dynamic Thermal Performance Simulation Model of an Energy Conserving Greenhouse With Thermal Storage

ABSTRACT A transient rather than steady-state analysis is required for accurate prediction, modification and control of a greenhouse thermal environment. In this study a dynamic mathematical model for predicting temperatures and moisture levels in a solar-assisted energy conserving circular (hoop) type greenhouse was developed. The greenhouse used in the development and testing of the model had added thermal mass in the form of water located under plant benches. Active and passive forms of thermal storage were investigated. Other energy conservation features incorporated in the test greenhouse included arch shutter thermal insulation applied in-between the double-layered inflated transparent plastic covers at night to reduce heat losses or heat gain. The greenhouse thermal model was programmed on a digital computer and comparisons of the greenhouse measured variables with model predictions showed a high degree of correlation.