Assessing the potential of residential HVAC systems for demand-side management

NARCIS (Netherlands)

van der Klauw, Thijs; Hoogsteen, Gerwin; Gerards, Marco Egbertus Theodorus; Hurink, Johann L.; Feng, Xianyong; Hebner, Robert E.

This paper investigates the potential of residential heating, ventilation and air conditioning systems to contribute to dynamic demand-side management. Thermal models for seven houses in Austin, Texas are developed with the goal of using them in a planning based demand-side management methodology.

Demand-Side Flexibility for Energy Transitions: Policy Recommendations for Developing Demand Response

OpenAIRE

Nursimulu, Anjali; Florin, Marie-Valentine; Vuille, François

2016-01-01

As a follow-up to IRGC's report on demand-side flexibility for energy transitions, this Policy Brief highlights that increasing flexibility in power systems is needed to accommodate higher shares of non-controllable and intermittent renewable generation, and that this requires changes to the market design and regulatory framework, to facilitate the development and deployment of appropriate technologies and market-based instruments (e.g. taxes and subsidies). The Policy Brief focuses on demand...

The electric energy demand-side planning: necessity and possibilities of execution

International Nuclear Information System (INIS)

Sposito, E.S.

1991-05-01

Aiming at reducing the level of investments, is presented a demand-side planning approach, divided into two parts. The first part is an analysis on the actual need of our demand-side approaching. In view of this, is showed a set of data and comments both on economic and technological aspects concerning the electric network and sector, as well as evaluation of the social, ecological and financial aspects which could act against the full expansion of the electric system. In the second part, a demand-side planning methodology is introduced, as well as its main concepts, its variables and its instruments of affecting the demand: energy conservation, replacement of sources, reduction of losses and electric power decentralized generation. Each of them is fully detailed in a set of planning policies and actions. Concluding is presented the basic elements of a National Electric Energy Substitution and Conservation Plan - PLANSCON. (author)

New Real-Time Market Facilitating Demand-Side Resources for System Balancing

DEFF Research Database (Denmark)

Feng, Donghan; Nyeng, Preben; Xie, Jun

2011-01-01

Many demand side resources have the potential to provide fast and low cost balancing services. Switching these devices on and off can be executed in seconds and have limited consequences for the customers if the duration is not long. With carefully designed market rules, tens of thousands...... the participation of demand-side resources. In light of the future environment of increasing intermittent renewable power and distributed energy/storage resources, stochastic time-series and Monte-Carlo simulation are used to analyze the relationship between balancing requirement and generation/demand uncertainties...

Demand side participation for frequency containment in the web of cells architecture

NARCIS (Netherlands)

Syed, M.H.; Burt, G.M.; Kok, J.K.; Hulst, R. d

2015-01-01

A large number of demand side management schemes have been proposed in literature for provision of frequency control ancillary services to the network. However, it is assumed that all the flexible devices within the network are managed and controlled under one demand side management (DSM) scheme. In

Controlling market power and price spikes in electricity networks: Demand-side bidding.

Science.gov (United States)

Rassenti, Stephen J; Smith, Vernon L; Wilson, Bart J

2003-03-04

In this article we report an experiment that examines how demand-side bidding can discipline generators in a market for electric power. First we develop a treatment without demand-side bidding; two large firms are allocated baseload and intermediate cost generators such that either firm might unilaterally withhold the capacity of its intermediate cost generators from the market to benefit from the supracompetitive prices that would result from only selling its baseload units. In a converse treatment, ownership of some of the intermediate cost generators is transferred from each of these firms to two other firms such that no one firm could unilaterally restrict output to spawn supracompetitive prices. Having established a well controlled data set with price spikes paralleling those observed in the naturally occurring economy, we also extend the design to include demand-side bidding. We find that demand-side bidding completely neutralizes the exercise of market power and eliminates price spikes even in the presence of structural market power.

Demand side resource operation on the Irish power system with high wind power penetration

International Nuclear Information System (INIS)

Keane, A.; Tuohy, A.; Meibom, P.; Denny, E.; Flynn, D.; Mullane, A.; O'Malley, M.

2011-01-01

The utilisation of demand side resources is set to increase over the coming years with the advent of advanced metering infrastructure, home area networks and the promotion of increased energy efficiency. Demand side resources are proposed as an energy resource that, through aggregation, can form part of the power system plant mix and contribute to the flexible operation of a power system. A model for demand side resources is proposed here that captures its key characteristics for commitment and dispatch calculations. The model is tested on the all island Irish power system, and the operation of the model is simulated over one year in both a stochastic and deterministic mode, to illustrate the impact of wind and load uncertainty. The results illustrate that demand side resources can contribute to the efficient, flexible operation of systems with high penetrations of wind by replacing some of the functions of conventional peaking plant. Demand side resources are also shown to be capable of improving the reliability of the system, with reserve capability identified as a key requirement in this respect. - Highlights: → Demand side resource model presented for use in unit commitment and dispatch calculations. → Benefits of demand side aggregation demonstrated specifically as a peaking unit and provider of reserve. → Potential to displace or defer construction of conventional peaking units.

Supply-side and demand-side policies for biosimilars: an overview in 10 European member states

OpenAIRE

R?muzat, C?cile; Kapu?niak, Anna; Caban, Aleksandra; Ionescu, Dan; Radi?re, Guerric; Mendoza, Cyril; Toumi, Mondher

2017-01-01

ABSTRACT Objective: This study aimed to provide an overview of biosimilar?policies in 10 EU MSs. Methods: Ten EU MS pharmaceutical markets (Belgium, France, Germany, Greece, Hungary, Italy, Poland, Spain, Sweden, and the UK) were selected. A comprehensive literature review?was performed to identify supply-side and demand-side policies in place in the selected countries. Results: Supply-side policies for biosimilars commonly include price linkage, price re-evaluation, and tendering; the use of...

Exploring Tradeoffs in Demand-Side and Supply-Side Management of Urban Water Resources Using Agent-Based Modeling and Evolutionary Computation

Directory of Open Access Journals (Sweden)

Lufthansa Kanta

2015-11-01

Full Text Available Urban water supply systems may be managed through supply-side and demand-side strategies, which focus on water source expansion and demand reductions, respectively. Supply-side strategies bear infrastructure and energy costs, while demand-side strategies bear costs of implementation and inconvenience to consumers. To evaluate the performance of demand-side strategies, the participation and water use adaptations of consumers should be simulated. In this study, a Complex Adaptive Systems (CAS framework is developed to simulate consumer agents that change their consumption to affect the withdrawal from the water supply system, which, in turn influences operational policies and long-term resource planning. Agent-based models are encoded to represent consumers and a policy maker agent and are coupled with water resources system simulation models. The CAS framework is coupled with an evolutionary computation-based multi-objective methodology to explore tradeoffs in cost, inconvenience to consumers, and environmental impacts for both supply-side and demand-side strategies. Decisions are identified to specify storage levels in a reservoir that trigger: (1 increases in the volume of water pumped through inter-basin transfers from an external reservoir; and (2 drought stages, which restrict the volume of water that is allowed for residential outdoor uses. The proposed methodology is demonstrated for Arlington, Texas, water supply system to identify non-dominated strategies for an historic drought decade. Results demonstrate that pumping costs associated with maximizing environmental reliability exceed pumping costs associated with minimizing restrictions on consumer water use.

Directed graph based carbon flow tracing for demand side carbon obligation allocation

DEFF Research Database (Denmark)

Sun, Tao; Feng, Donghan; Ding, Teng

2016-01-01

In order to achieve carbon emission abatement, some researchers and policy makers have cast their focus on demand side carbon abatement potentials. This paper addresses the problem of carbon flow calculation in power systems and carbon obligation allocation at demand side. A directed graph based...... method for tracing carbon flow is proposed. In a lossy network, matrices such as carbon losses, net carbon intensity (NCI) and footprint carbon intensity (FCI) are obtained with the proposed method and used to allocate carbon obligation at demand side. Case studies based on realistic distribution...... and transmission systems are provided to demonstrate the effectiveness of the proposed method....

Internet of Things, Challenges for Demand Side Management

Directory of Open Access Journals (Sweden)

Simona-Vasilica OPREA

2017-01-01

Full Text Available The adoption of any new product means also the apparition of new issues and challenges, and this is especially true when we talk about a mass adoption. The advent of Internet of Things (IoT devices will be, in the authors of this paper opinion, the largest and the fastest product adoption yet to be seen, as several early sources were predicting a volume of 50 billion IoT devices to be active by 2020 [1][2]. While later forecasts reduced the predicted amount to about 20-30 billion devices [3], even for such “reduced” number, demand side management issues are foreseeable, for the potential economic impact of IoT applications in 2025 will be between 3.9 and $11.1 trillion USD [4]. Not only that new patterns will emerge in energy consumption and Internet traffic, but we predict that the sheer amount of data produced by this quantity of IoT devices will give birth to a new sort of demand side management, the demand side management of IoT data. How will this work is yet to be seen but, at the current moment, one can at least identify the bits and pieces that will constitute it. This paper is intended to serve as short guide regarding the possible challenges raised by the adoption of IoT devices. The data types and structures, lifecycle and patterns will be briefly discussed throughout the following article.

An energy service company's perspective on demand-side management

International Nuclear Information System (INIS)

Bullock, C.G.

1993-01-01

In 1985, Massachusetts Electric Company held a bid for demand reduction to be supplied by energy service companies (ESCOs). It was one of the first demand-side management (DSM) bidding programs held in the United States. Since then, several DSM auctions have been held. Many people expected DSM bidding to be a key component in integrated resource planning. Many observed similarities with supply side bidding, and expected DSM bidding to grow according. Today, more than $2 billion annually is being spent by utilities on DSM programs. Less than $100 million is spent with ESCOs. This chapter explores some of the reasons for the current situation and suggests some alternatives, which could benefit all of the players

Predictive Control of Demand Side Units Participating in the Primary Frequency Reserve Market

DEFF Research Database (Denmark)

Biegel, Benjamin; Stoustrup, Jakob; Andersen, Palle

2013-01-01

We consider an aggregator controlling a mixed portfolio of conventional power generators and demand side units. The generators are controllable within certain power and ramp limitations while the demand side units are characterized by flexible consumptions and therefore can be treated as energy...

Individual-motivational factors in the acceptability of demand-side and supply-side measures to reduce carbon emissions

International Nuclear Information System (INIS)

Poortinga, Wouter; Spence, Alexa; Demski, Christina; Pidgeon, Nick F.

2012-01-01

As more than a third of all carbon dioxide emissions in the UK are generated by the domestic sector, individuals need to make drastic changes to their current lifestyle in order to play their part in climate change mitigation. Not only do they need to change their personal behaviour, they also have to accept new low-carbon technologies in order to decarbonise the energy they are using. This study uses an adapted version of the Value–Belief-Norm (VBN) model () to examine individual-motivational factors in the acceptability of demand-side and supply-side strategies to reduce carbon emissions. The study found that environmental identity, climate change concern, and personal norms are all significantly associated with the acceptability of both demand-side measures and supply-side technologies. While personal values were also important, their associations were mediated by more specific factors. Overall, the adapted VBN model was better able to explain the acceptability of low-carbon behaviours than of low-carbon energy-supply technologies. Concern about energy security appeared to be of limited importance. It was negatively associated with the willingness to engage in low-carbon behaviours, suggesting that a shift in focus towards energy security issues may not necessarily help a transition to a low-carbon society. - Highlights: ► An adapted VBN model is proposed to study environmentally significant behaviour.► Environmental identity is important for both demand-side and supply-side measures.► Energy security concern is of limited importance to support for supply-side measures.► Energy security concern reduces the willingness to engage in low-carbon behaviours.

Balancing islanded residential microgrids using demand side management

NARCIS (Netherlands)

Hoogsteen, Gerwin; van der Klauw, Thijs; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria; Feng, Xianyong; Hebner, Robert E.

2016-01-01

Now that the internet of things is emerging, control of domestic assets within the smart micro grids is also gaining interest. Furthermore, these micro grids may operate in islanded mode for short periods. Various demand side management approaches are presented in literature to control these assets.

Using demand-side management to decrease transformer ageing

NARCIS (Netherlands)

van der Klauw, Thijs; Gerards, Marco Egbertus Theodorus; Hurink, Johann L.

2016-01-01

The introduction of local, often uncontrollable, generation units as well as larger loads such as electric vehicles (EVs) causes an increasing amount of stress on our energy supply chain, specifically on the distribution grids. Demand-side management (DSM) is often seen as a potential technology to

Demand side integration aspects in active distribution planning

DEFF Research Database (Denmark)

Silvestro, Federico; Baitch, Alex; Pilo, Fabrizio

2013-01-01

will be implemented in practice? How will regulatory frameworks and connection agreements evolve to support ADSs? The present work provides some information about the closer and closer integration between network planning and Demand Side Integration that is foreseen in the future and shows the necessity to develop...

Primary Control by ON/OFF Demand-Side Devices

DEFF Research Database (Denmark)

Biegel, Benjamin; Hansen, Lars Henrik; Andersen, Palle

2013-01-01

We consider an aggregator managing a portfolio of ON/OFF demand-side devices. The devices are able to shift con- sumption in time within certain energy limitations; moreover, the devices are able to measure the system frequency and switch ON and OFF accordingly. We show how the aggregator can...

Co-optimization of Energy and Demand-Side Reserves in Day-Ahead Electricity Markets

Science.gov (United States)

Surender Reddy, S.; Abhyankar, A. R.; Bijwe, P. R.

2015-04-01

This paper presents a new multi-objective day-ahead market clearing (DAMC) mechanism with demand-side reserves/demand response (DR) offers, considering realistic voltage-dependent load modeling. The paper proposes objectives such as social welfare maximization (SWM) including demand-side reserves, and load served error (LSE) minimization. In this paper, energy and demand-side reserves are cleared simultaneously through co-optimization process. The paper clearly brings out the unsuitability of conventional SWM for DAMC in the presence of voltage-dependent loads, due to reduction of load served (LS). Under such circumstances multi-objective DAMC with DR offers is essential. Multi-objective Strength Pareto Evolutionary Algorithm 2+ (SPEA 2+) has been used to solve the optimization problem. The effectiveness of the proposed scheme is confirmed with results obtained from IEEE 30 bus system.

Using Demand Side Management to Adapt to Water Scarcity and ...

International Development Research Centre (IDRC) Digital Library (Canada)

The Saiss is a sub-basin of the Sebou basin in Northern Morocco. Due to decreased precipitation and increased water demand, the surface waters of the Saiss basin have been greatly reduced. At the current rate of exploitation, the aquifer will be depleted within 25 years. This project will examine whether demand-side ...

Impact of Demand Side Management in Active Distribution Networks

DEFF Research Database (Denmark)

Ponnaganti, Pavani; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

2017-01-01

Demand Side Management (DSM) is an efficient flexible program which helps distribution network operators to meet the future critical peak demand. It is executed in cases of not only technical issues like voltage sag or swell, transformer burdening, cable congestions, but also to increase the degree...... of visibility in the electricity markets. The aim of this paper is to find the optimal flexible demands that can be shifted to another time in order to operate the active distribution system within secure operating limits. A simple mechanism is proposed for finding the flexibility of the loads where electric...

Dynamics of energy-related CO2 emissions in China during 1980-2002: the relative importance of energy supply-side and demand-side effects

International Nuclear Information System (INIS)

Libo Wu; Kaneko, Shinji; Matsuoka, Shunji

2006-01-01

Based on a newly developed model that integrates energy production, transformation and consumption processes, this paper compares the relative importance of some traditionally recognized factors operating on the energy demand side with a body of newly defined factors on the supply side, in terms of their contribution to trends in China's CO 2 emissions related to the total primary energy supply (C-TPES). Before 1996, changes in China's C-TPES were mainly driven by changes on the energy demand side. Factors operating on the energy supply side played trivial roles. During the period 1996-2000, however, increasing demand-side effects declined dramatically and at the same time decreasing effects from supply side expanded significantly. Such changes resulted directly in a decline in the C-TPES. The decreasing effects from international trade as well as statistical imbalances between supply and demand reinforced the declining trend. The shrinkage of demand side effects mainly arose from the slowdown of economic growth and speed of decrease in energy intensity. The expansion of supply-side effects was principally attributed to the speed of decrease in gross unit consumption in transformation sectors, especially in electricity sector. Therefore, the acceleration of efficiency improvements in end-use and transformation sectors accounted for the decline in the C-TPES over the period 1996-2000. (author)

Game Demands of Seven-A-Side Soccer in Young Players.

Science.gov (United States)

Barbero-Alvarez, José C; Gómez-López, Maite; Castagna, Carlo; Barbero-Alvarez, Verónica; Romero, David V; Blanchfield, Anthony W; Nakamura, Fábio Y

2017-07-01

Barbero-Alvarez, JC, Gómez-López, M, Castagna, C, Barbero-Alvarez, V, Romero, DV, Blanchfield, AW, and Nakamura, FY. Game demands of seven-a-side soccer in young players. J Strength Cond Res 31(7): 1771-1779, 2017-The aim of this study was to examine the activity patterns and physiological demands of 7-a-side youth soccer matches across 2 chronological age categories (U12 and U14). Twenty-two soccer players of a national youth soccer academy were investigated. Players of each age category performed 2 training matches (2 × 25 minutes) and were monitored by global positioning system and heart rate monitor units. Players of both categories covered similar total distance (5,348 ± 307 m), at similar mean heart rate values (86 ± 4% of maximum). However, the number of high-intensity runs (82.5 ± 17.4 vs. 69.7 ± 15.2) and total distance covered during sprints (264 ± 207 vs. 128 ± 74 m) were significantly (p ≤ 0.05) higher in U14 compared with U12. The results suggest a highly demanding nature of 7-a-side soccer for skilled players, with physical maturity possibly influencing the match-related high-intensity performance at these ages.

Real-Time Demand Side Management Algorithm Using Stochastic Optimization

Directory of Open Access Journals (Sweden)

Moses Amoasi Acquah

2018-05-01

Full Text Available A demand side management technique is deployed along with battery energy-storage systems (BESS to lower the electricity cost by mitigating the peak load of a building. Most of the existing methods rely on manual operation of the BESS, or even an elaborate building energy-management system resorting to a deterministic method that is susceptible to unforeseen growth in demand. In this study, we propose a real-time optimal operating strategy for BESS based on density demand forecast and stochastic optimization. This method takes into consideration uncertainties in demand when accounting for an optimal BESS schedule, making it robust compared to the deterministic case. The proposed method is verified and tested against existing algorithms. Data obtained from a real site in South Korea is used for verification and testing. The results show that the proposed method is effective, even for the cases where the forecasted demand deviates from the observed demand.

Energy efficiency and demand side management. Complement or contradiction? The impact of energy efficiency measures on the potential for demand side management; Energieeffizienz und Lastflexibilisierung. Partner oder Gegenspieler? Der Einfluss von Energieeffizienzmassnahmen auf das Lastflexibilisierungspotenzial

Energy Technology Data Exchange (ETDEWEB)

Peraus, Sebastian [TU Muenchen (Germany). Maschinenwesen; Gruber, Anna; Roon, Serafin von [Forschungsgesellschaft fuer Energiewirtschaft mbH, Muenchen (Germany)

2013-02-01

The success of the so called ''Energiewende'' in Germany is based on two major elements: the improvements in energy efficiency and the increase of renewable energy sources (RES). But the supply of RES cannot always be regulated according to the electricity demand. As a result both flexible electricity generation and demand side management will become increasingly important. Consequently, it has to be discussed, whether the improvement of energy efficiency and demand side management could interfere. This publication will illustrate the possible impact of energy efficiency measures on the potential for demand side management.

Determining optimum levels of DSM [demand-side management] as a supply-side resource

International Nuclear Information System (INIS)

Giles, S.H.; Mitchell, E.D.

1990-01-01

San Diego Gas and Electric Company (SDGE) recommends the evaluation of demand-side management as a supply-side resource. The advantages of concurrent economic analysis of DSM options with other traditional sources represents a significant improvement over analysis either before or after the development of a resource plan. The evaluation of utility-sponsored DSM programs that provide system benefits that include deferment of capacity additions and improvements in more efficient system operation should be evaluated side-by-side with traditional resources that provide similar benefits. The utility decision to either provide capital costs to construct a power plant or make demand payments for a power purchase is directly analogous to the decision to provide funding for a DSM program that would defer these same investments. Both types of decision represent utility control over investment decisions that allow the utility to provide reliable, low-cost power to its customers. SDGE has also had experience with using generation expansion scenarios to test different levels of pre-selected packages of DSM programs, attempting to evaluate the total costs of system expansion for each of the different packages. This method was fraught with problems, and the best information that could be gained was if the selection of DSM packages happened to bracket a lower cost scenario, when it could reasonably be assumed that both smaller and larger levels of DSM were not as cost effective as the intermediate level. However, in many cases the selection of DSM programs did not produce this result and the important question of whether individual DSM programs were worthwhile when evaluated individually, or whether the lowest cost scenario would be improved with more or less DSM, could not be answered

Air pollution impacts from demand-side management

International Nuclear Information System (INIS)

Hall, D.C.; Sandii Win, M.; Hall, J.V.

1995-01-01

Air-polluting emission rates and energy-efficiency ratings vary widely among power plants, depending on location, age and whether the power plant is repowered. Traditional regulations require installation of specified emission control equipment that varies among power plants. These regulations do not specify that utilities first dispatch the cleanest power plants as demand varies from peak to off-peak periods. This empirical analysis shows, for 2 years out of 20, that demand-side management (DSM) programs increase air pollution. One reason for this result is that regulations require installation of specific emission-control technology but do not provide the incentive to take actual emissions or their air quality impacts into account when operating the system. For certain types of air pollutants and in some regions, regulatory programs now include markets for tradable emission credits. Such programs may alter this incentive. (author)

Demand-side management and demand response in the Ontario energy sectors

International Nuclear Information System (INIS)

2003-01-01

In June 2003, the Ontario Energy Board was asked by the Minister of Energy to identify and review options for the delivery of demand-side management (DSM) and demand response (DR) activities within the electricity sector, by consulting with stakeholders. The role of local distribution company (distributor) in such activities was also to be determined. The objective was to balance implementation costs with the benefits to consumers and the entire system. The preliminary research and ideas were presented in this discussion paper. Definitions of both DSM and DR were provided, followed by an overview of economic theory and competitive markets. The framework for discussion was presented, along with a list of issues and other considerations. A spectrum of potential approaches to a DSM and DR framework was included and jurisdictional examples provided. A brief overview of the concept of load aggregation was presented and the next steps for consultations were outlined. 30 refs., 7 tabs

The Demand Side in Economic Models of Energy Markets: The Challenge of Representing Consumer Behavior

Energy Technology Data Exchange (ETDEWEB)

Krysiak, Frank C., E-mail: frank.krysiak@unibas.ch; Weigt, Hannes [Department of Business and Economics, University of Basel, Basel (Switzerland)

2015-05-19

Energy models play an increasing role in the ongoing energy transition processes either as tools for forecasting potential developments or for assessments of policy and market design options. In recent years, these models have increased in scope and scale and provide a reasonable representation of the energy supply side, technological aspects and general macroeconomic interactions. However, the representation of the demand side and consumer behavior has remained rather simplistic. The objective of this paper is twofold. First, we review existing large-scale energy model approaches, namely bottom-up and top-down models, with respect to their demand-side representation. Second, we identify gaps in existing approaches and draft potential pathways to account for a more detailed demand-side and behavior representation in energy modeling.

The Demand Side in Economic Models of Energy Markets: The Challenge of Representing Consumer Behavior

Directory of Open Access Journals (Sweden)

Frank eKrysiak

2015-05-01

Full Text Available Energy models play an increasing role in the ongoing energy transition processes either as tools for forecasting potential developments or for assessments of policy and market design options. In recent years these models have increased in scope and scale and provide a reasonable representation of the energy supply side, technological aspects and general macroeconomic interactions. However, the representation of the demand side and consumer behavior has remained rather simplistic. The objective of this paper is twofold. First, we review existing large scale energy model approaches, namely bottom-up and top-down models, with respect to their demand side representation. Second, we identify gaps in existing approaches and draft potential pathways to account for a more detailed demand side and behavior representation in energy modeling.

The Demand Side in Economic Models of Energy Markets: The Challenge of Representing Consumer Behavior

International Nuclear Information System (INIS)

Krysiak, Frank C.; Weigt, Hannes

2015-01-01

Energy models play an increasing role in the ongoing energy transition processes either as tools for forecasting potential developments or for assessments of policy and market design options. In recent years, these models have increased in scope and scale and provide a reasonable representation of the energy supply side, technological aspects and general macroeconomic interactions. However, the representation of the demand side and consumer behavior has remained rather simplistic. The objective of this paper is twofold. First, we review existing large-scale energy model approaches, namely bottom-up and top-down models, with respect to their demand-side representation. Second, we identify gaps in existing approaches and draft potential pathways to account for a more detailed demand-side and behavior representation in energy modeling.

Joint Planning Of Energy Storage and Transmission Considering Wind-Storage Combined System and Demand Side Response

Science.gov (United States)

Huang, Y.; Liu, B. Z.; Wang, K. Y.; Ai, X.

2017-12-01

In response to the new requirements of the operation mode of wind-storage combined system and demand side response for transmission network planning, this paper presents a joint planning of energy storage and transmission considering wind-storage combined system and demand side response. Firstly, the charge-discharge strategy of energy storage system equipped at the outlet of wind farm and demand side response strategy are analysed to achieve the best comprehensive benefits through the coordination of the two. Secondly, in the general transmission network planning model with wind power, both energy storage cost and demand side response cost are added to the objective function. Not only energy storage operation constraints and but also demand side response constraints are introduced into the constraint condition. Based on the classical formulation of TEP, a new formulation is developed considering the simultaneous addition of the charge-discharge strategy of energy storage system equipped at the outlet of the wind farm and demand side response strategy, which belongs to a typical mixed integer linear programming model that can be solved by mature optimization software. The case study based on the Garver-6 bus system shows that the validity of the proposed model is verified by comparison with general transmission network planning model. Furthermore, the results demonstrate that the joint planning model can gain more economic benefits through setting up different cases.

DSM [demand-side management] opportunities in Alberta: An economist's perspective

International Nuclear Information System (INIS)

Woodward, R.S.

1990-01-01

In Alberta, utility companies are placing increasing attention on demand-side management (DSM) as one option for meeting future demand. Some basic economic principles are provided to yield a guideline on how much a utility should be spending on DSM initiatives. For the case of financial incentives to customers, it is shown that subsidies based on sound economic principles will enable the utility to charge lower overall rates to customers receiving the subsidy without raising other customers' rates. Moving outside of a well-understood market-based system and into a fully centralized planning approach to DSM eliminates a critical link between utilities and their customers. In Alberta, DSM measures appropriate in other regions will not be appropriate due to the province's unique supply and demand characteristics. Most of Alberta's electricity supply comes from low-cost coal-fired plants. On the demand-side, there is a significant concentration of large industrial and commercial consumers, notably in the oil and gas industry, and there is essentially no demand for electric heating in homes since natural gas is very abundant. The Alberta integrated power system currently operates at a load factor of ca 77%, reflecting the large industrial demand and the absence of a winter peaking effect associated with electrical heating requirements. A relatively small difference in embedded and incremental electricity supply costs means that utilities have little to spend on DSM programs. The identification of cost-effective DSM opportunities, most of which are likely to be found in the industrial sector, requires a considerable amount of detailed information on consumer behavior and close collaboration between utility and customer

Load building versus conservation as demand-side management objectives

International Nuclear Information System (INIS)

Kexel, D.T.

1994-01-01

This paper examines the economics of load building versus conservation as demand-side management objectives. Economic criteria to be used in evaluating each type of program from the perspectives of all impacted parties are provided. The impact of DSM programs on electric rates is shown to be a key focal point of a thorough evaluation

Demand side resource operation on the Irish power system with high wind power penetration

DEFF Research Database (Denmark)

Keane, A.; Tuohy, A.; Meibom, Peter

2011-01-01

part of the power system plant mix and contribute to the flexible operation of a power system. A model for demand side resources is proposed here that captures its key characteristics for commitment and dispatch calculations. The model is tested on the all island Irish power system, and the operation...... of the functions of conventional peaking plant. Demand side resources are also shown to be capable of improving the reliability of the system, with reserve capability identified as a key requirement in this respect....... of the model is simulated over one year in both a stochastic and deterministic mode, to illustrate the impact of wind and load uncertainty. The results illustrate that demand side resources can contribute to the efficient, flexible operation of systems with high penetrations of wind by replacing some...

The impact of demand side management strategies in the penetration of renewable electricity

International Nuclear Information System (INIS)

Pina, André; Silva, Carlos; Ferrão, Paulo

2012-01-01

High fuel costs, increasing energy security and concerns with reducing emissions have pushed governments to invest in the use of renewable energies for electricity generation. However, the intermittence of most renewable resources when renewable energy provides a significant share of the energy mix can create problems to electricity grids, which can be minimized by energy storage systems that are usually not available or expensive. An alternative solution consists on the use of demand side management strategies, which can have the double effect of reducing electricity consumption and allowing greater efficiency and flexibility in the grid management, namely by enabling a better match between supply and demand. This work analyzes the impact of demand side management strategies in the evolution of the electricity mix of Flores Island in the Azores archipelago which is characterized by high shares of renewable energy and therefore the introduction of more renewable energy sources makes it an interesting case study for testing innovative solutions. The electricity generation system is modeled in TIMES, a software which optimizes the investment and operation of wind and hydro plants until 2020 based on scenarios for demand growth, deployment of demand response technologies in the domestic sector and promotion of behavioral changes to eliminate standby power. The results show that demand side management strategies can lead to a significant delay in the investment on new generation capacity from renewable resources and improve the operation of the existing installed capacity. -- Highlights: ► Energy efficiency can help reduce the need for investment in more renewable energy. ► Dynamic demand helps increase the use of renewable energy in low demand periods. ► Around 40% of total consumption by domestic appliances is used as dynamic demand. ► The load of domestic appliances is mainly shifted to the 5:00 to 9:00 period.

How to introduce demand side resources in the design of low-carbon power systems in China

Science.gov (United States)

Zhou, Pengcheng; Liu, Yiqun; Zeng, Ming; Sun, Chenjun

2018-04-01

Nowadays, China's energy demand sustained rapid growth, and the coal-based energy structure has adverse effects on the environment. The flexibility of demand side resource (DSR) will be greatly improved, and DSR can reduce electricity consumption actively and temporarily, and realize energy saving and emission reduction. But there are still some problems to introduce DSR in China. This paper proposes three practices for introducing demand side resources to improve the flexibility of power systems through demand resources.

Demand side management program evaluation based on industrial and commercial field data

International Nuclear Information System (INIS)

Eissa, M.M.

2011-01-01

Demand Response is increasingly viewed as an important tool for use by the electric utility industry in meeting the growing demand for electricity. There are two basic categories of demand response options: time varying retail tariffs and incentive Demand Response Programs. is applying the time varying retail tariffs program, which is not suitable according to the studied load curves captured from the industrial and commercial sectors. Different statistical studies on daily load curves for consumers connected to 22 kV lines are classified. The load curve criteria used for classification is based on peak ratio and night ratio. The data considered here is a set of 120 annual load curves corresponding to the electric power consumption (the western area in the King Saudi Arabia (KSA)) of many clients in winter and some months in the summer (peak period). The study is based on real data from several Saudi customer sectors in many geographical areas with larger commercial and industrial customers. The study proved that the suitable Demand Response for the ESC is the incentive program. - Highlights: → Study helps in selecting the proper demand side program. → A credit will be given for the customers during summer months. → Reduction in the electric bill. → Monthly bill credit is decreased based on customers' peak load reduction. → Guide for applying the proper demand side program suitable for the utility and customers.

Impact of realistic communications for fast-acting demand side management

DEFF Research Database (Denmark)

Dambrauskas, Paulius; Syed, Mazheruddin H.; Blair, Steven M.

2017-01-01

The rising penetration of intermittent energy resources is increasing the need for more diverse electrical energy resources that are able to support ancillary services. Demand side management (DSM) has a significant potential to fulfil this role, but several challenges are still impeding the wide...

Smart grid dispatch strategy for on/off demand-side devices

DEFF Research Database (Denmark)

Biegel, Benjamin; Andersen, Palle; Pedersen, Tom S.

2013-01-01

We consider an aggregator managing a portfolio of runtime and downtime constrained ON/OFF demand-side devices. The devices are able to shift consumption in time within certain energy limitations. We show how the aggregator can manage the portfolio of devices to collectively provide upward...

Neural network controller for Active Demand-Side Management with PV energy in the residential sector

International Nuclear Information System (INIS)

Matallanas, E.; Castillo-Cagigal, M.; Gutiérrez, A.; Monasterio-Huelin, F.; Caamaño-Martín, E.; Masa, D.; Jiménez-Leube, J.

2012-01-01

Highlights: ► We have developed a neural controller for Active Demand-Side Management. ► The controller consists of Multilayer Perceptrons evolved with a genetic algorithm. ► The architecture of the controller is distributed and modular. ► The simulations show that the electrical local behavior improves. ► Active Demand-Side Management helps users to control his energy behaviour. -- Abstract: In this paper, we describe the development of a control system for Demand-Side Management in the residential sector with Distributed Generation. The electrical system under study incorporates local PV energy generation, an electricity storage system, connection to the grid and a home automation system. The distributed control system is composed of two modules: a scheduler and a coordinator, both implemented with neural networks. The control system enhances the local energy performance, scheduling the tasks demanded by the user and maximizing the use of local generation.

49 CFR 229.69 - Side bearings.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Side bearings. 229.69 Section 229.69....69 Side bearings. (a) Friction side bearings with springs designed to carry weight may not have more than 25 percent of the springs in any one nest broken. (b) Friction side bearings may not be run in...

Experimental determination of demand side management potential of wet appliances in the Netherlands

NARCIS (Netherlands)

Staats, M. R.; de Boer-Meulman, P. D M; van Sark, W. G J H M

2017-01-01

The potential of demand side management (DSM) of wet appliances (washing machine, dishwasher and tumble dryer) in households with photovoltaic (PV) systems is studied experimentally focusing on evening peak demand reduction and increase in PV self-consumption. In a sample of 100 Dutch households the

Ground reaction forces and frictional demands during stair descent: effects of age and illumination.

Science.gov (United States)

Christina, Kathryn A; Cavanagh, Peter R

2002-04-01

Stair descent is an inherently risky and demanding task that older adults often encounter in everyday life. It is believed that slip between the foot or shoe sole and the stair surface may play a role in stair related falls, however, there are no reports on slip resistance requirements for stair descent. The aim of this study was to determine the required coefficient of friction (RCOF) necessary for safe stair descent in 12 young and 12 older adults, under varied illuminance conditions. The RCOF during stair descent was found to be comparable in magnitude and time to that for overground walking, and thus, with adequate footwear and dry stair surfaces, friction does not appear to be a major determinant of stair safety. Illuminance level had little effect on the dependent variables quantified in this study. However, the older participants demonstrated safer strategies than the young during stair descent, as reflected by differences in the ground reaction forces and lower RCOF.

Linking meters and markets: Roles and incentives to support a flexible demand side

DEFF Research Database (Denmark)

Katz, Jonas

2014-01-01

wholesale market participants to the demand side is mostly infeasible, resulting in flexibility tasks being aggregated and delegated to balancing responsible wholesale traders. This analysis focuses on whether current incentives and roles are appropriate and where the design could be improved to establish......Present trends in the development of electricity systems are expected to generate a growing need for flexibility in decentralised resources, including demand response. In order to enable decentralised actors to create value, the organisation of markets and incentives should incorporate these new...... a flexible demand side with a particular focus on the Danish case. Design-related barriers are identified that affect expected value, associated risks, and the distribution of responsibilities. This serves as a basis to define policy options in the context of Nordic electricity markets. © 2014 Elsevier Ltd...

2D granular flows with the μ(I) rheology and side walls friction: A well-balanced multilayer discretization

Science.gov (United States)

Fernández-Nieto, E. D.; Garres-Díaz, J.; Mangeney, A.; Narbona-Reina, G.

2018-03-01

We present here numerical modelling of granular flows with the μ (I) rheology in confined channels. The contribution is twofold: (i) a model to approximate the Navier-Stokes equations with the μ (I) rheology through an asymptotic analysis; under the hypothesis of a one-dimensional flow, this model takes into account side walls friction; (ii) a multilayer discretization following Fernández-Nieto et al. (2016) [20]. In this new numerical scheme, we propose an appropriate treatment of the rheological terms through a hydrostatic reconstruction which allows this scheme to be well-balanced and therefore to deal with dry areas. Based on academic tests, we first evaluate the influence of the width of the channel on the normal profiles of the downslope velocity thanks to the multilayer approach that is intrinsically able to describe changes from Bagnold to S-shaped (and vice versa) velocity profiles. We also check the well-balanced property of the proposed numerical scheme. We show that approximating side walls friction using single-layer models may lead to strong errors. Secondly, we compare the numerical results with experimental data on granular collapses. We show that the proposed scheme allows us to qualitatively reproduce the deposit in the case of a rigid bed (i.e. dry area) and that the error made by replacing the dry area by a small layer of material may be large if this layer is not thin enough. The proposed model is also able to reproduce the time evolution of the free surface and of the flow/no-flow interface. In addition, it reproduces the effect of erosion for granular flows over initially static material lying on the bed. This is possible when using a variable friction coefficient μ (I) but not with a constant friction coefficient.

Modeling and Analysis of Commercial Building Electrical Loads for Demand Side Management

Science.gov (United States)

Berardino, Jonathan

In recent years there has been a push in the electric power industry for more customer involvement in the electricity markets. Traditionally the end user has played a passive role in the planning and operation of the power grid. However, many energy markets have begun opening up opportunities to consumers who wish to commit a certain amount of their electrical load under various demand side management programs. The potential benefits of more demand participation include reduced operating costs and new revenue opportunities for the consumer, as well as more reliable and secure operations for the utilities. The management of these load resources creates challenges and opportunities to the end user that were not present in previous market structures. This work examines the behavior of commercial-type building electrical loads and their capacity for supporting demand side management actions. This work is motivated by the need for accurate and dynamic tools to aid in the advancement of demand side operations. A dynamic load model is proposed for capturing the response of controllable building loads. Building-specific load forecasting techniques are developed, with particular focus paid to the integration of building management system (BMS) information. These approaches are tested using Drexel University building data. The application of building-specific load forecasts and dynamic load modeling to the optimal scheduling of multi-building systems in the energy market is proposed. Sources of potential load uncertainty are introduced in the proposed energy management problem formulation in order to investigate the impact on the resulting load schedule.

Review of US utility demand-side bidding programs

International Nuclear Information System (INIS)

Goldman, C.A.; Kito, M.S.

1995-01-01

In this study, we review utility experiences with demand-side management (DSM) bidding programs. Since 1987, about 35 US utilities have signed long-term contracts with developers of DSM resources (ie energy service companies and customers) to provide a quantity of demand and energy savings at specified prices. Total resource costs range between 5.4 and 8 cents/kWh for DSM bidding programs where complete information on program costs is available. Almost all DSM bidding programs have been cost-effective compared with the utility's own supply-side alternatives, although there is substantial disagreement regarding the value of these programs compared with the utility's own DSM programs. In most bidding programs, payments to bidders account for between 70 and 90% of total program costs. Variation in winning bid prices is influenced primarily by DSM bid ceiling prices, differences in the mix of measures and markets targeted by developers, and the degree of performance risk borne by the DSM developer. Bids targeting residential customers averaged 6.2 cents/kWh compared with about 5.0 cents/kWh for commercial/industrial bids. We also compared the costs of acquiring lighting savings in DSM bidding contracts with a sample of 20 utility sponsored commercial/industrial lighting programs. We found that, on average total resource costs were slightly higher in bidding programs (6.1 vs 5.6 cents/kWh), although ratepayers bear significantly less performance risk in bidding programs compared with traditional utility-sponsored DSM programs. (author)

Decision support program for congestion management using demand side flexibility

DEFF Research Database (Denmark)

Esmat, Ayman; Pinson, Pierre; Usaola, Julio

2017-01-01

In the past decades, Distribution System Operators (DSOs) have been mitigating distribution networks (DNs) contingencies by opting to grid reinforcements. However, this approach is not always cost and time efficient. Demand Side Flexibility (DSF) is one of the recent alternatives used in DNs cong...... effect is taken into consideration as well as the uncertain behavior of customers. Finally, the distribution grid of the Danish Bornholm Island is used to illustrate the merits of the DSP. The total cost incurred by the DSO is calculated and presented.......In the past decades, Distribution System Operators (DSOs) have been mitigating distribution networks (DNs) contingencies by opting to grid reinforcements. However, this approach is not always cost and time efficient. Demand Side Flexibility (DSF) is one of the recent alternatives used in DNs...... congestion management. Consequently, new market players such as aggregators are needed to handle DSF transaction between customers and DSOs. This paper proposes and models a decision support program (DSP) to optimize the total cost charged by the DSO for using DSF services. Moreover, the energy rebound...

New vision of demand side management strategy as the main tool in cooperation suppliers and consumers of electrical energy

International Nuclear Information System (INIS)

Szkutnik, J.

2012-01-01

The paper presents the complex proposal for the implementation of the demand side management in the Polish energy sector. The issue of demand side management is well known in the world, European and domestic dimensions. The experience of western countries shows that at least to some extent, the demand side management strategy is already implemented there. However, Polish experience is far too insufficient. Demand side management consists in efficient management of energy demand as well as adoption of this demand i.e. changing the load. The decrease of energy consumption in the moment of its peak demand leads to the balance between the demand and supply in the system, which influences the market price of energy. If certain mechanisms are implemented that will cause that final receivers will be willing to adjust their demand for energy, we will create the Demand Response, which is an efficient tool in the demand side management strategy. It is assumed that electronic meters will bring a real quality change. The undertakings based on initiatives of the Polish Energy Regulatory Office that promote the concept of implementation of electronic metering in the Polish energy sector prove that Poland is determined to improve its energy efficiency. The report describes the concept of the electronic meters that enables the realisation of the demand side management strategy as well as other complementary solutions that make the strategy even more efficient. In this field, it is planned to establish a dedicated loyalty programmes for energy receivers. The concept includes also the combination of the model solutions with the campaign 'energy efficiency' organised by the Ministry of Economy, which aims at fulfilling the requirements of the directive 2006/32/EC on energy end-use efficiency and energy services. As complementary solution in this new vision to add the system of recycling of waste heat home appliance devices. (Author)

A Simulation of Rainwater Harvesting Design and Demand-Side Controls for Large Hospitals

Directory of Open Access Journals (Sweden)

Lawrence V. Fulton

2018-05-01

Full Text Available Inpatient health buildings in the United States are the most intensive users of water among large commercial buildings. Large facilities (greater than 1 million square feet consume an average of 90 million gallons per building per year. The distribution and treatment of water imposes a significant electrical power demand, which may be the single largest energy requirement for various states. Supply and demand-side solutions are needed, particularly in arid and semi-arid regions where water is scarce. This study uses continuous simulations based on 71 years of historical data to estimate how rainwater harvesting systems and demand-side interventions (e.g., low-flow devices, xeriscaping would offset the demand for externally-provided water sources in a semi-arid region. Simulations from time series models are used to generate alternative rainfall models to account for potential non-stationarity and volatility. Results demonstrate that hospital external water consumption might be reduced by approximately 25% using conservative assumptions and depending on the design of experiment parameters associated with rainfall capture area, building size, holding tank specifications, and conservation efforts.

Industrial demand side management: A status report

Energy Technology Data Exchange (ETDEWEB)

Hopkins, M.F.; Conger, R.L.; Foley, T.J. [and others

1995-05-01

This report provides an overview of and rationale for industrial demand side management (DSM) programs. Benefits and barriers are described, and data from the Manufacturing Energy Consumption Survey are used to estimate potential energy savings in kilowatt hours. The report presents types and examples of programs and explores elements of successful programs. Two in-depth case studies (from Boise Cascade and Eli Lilly and Company) illustrate two types of effective DSM programs. Interviews with staff from state public utility commissions indicate the current thinking about the status and future of industrial DSM programs. A comprehensive bibliography is included, technical assistance programs are listed and described, and a methodology for evaluating potential or actual savings from projects is delineated.

Large Friction Anisotropy of a Polydiacetylene Monolayer

International Nuclear Information System (INIS)

Burns, A.R.; Carpick, R.W.; Sasaki, D.Y.

1999-01-01

Friction force microscopy measurements of a polydiacetylene monolayer film reveal a 300% friction anisotropy that is correlated with the film structure. The film consists of a monolayer of the red form of N-(2-ethanol)- 10,12 pentacosadiynamide, prepared on a Langmuir trough and deposited on a mica substrate. As confirmed by atomic force microscopy and fluorescence microscopy, the monolayer consists of domains of linearly oriented conjugated backbones with pendant hydrocarbon side chains above and below the backbones. Maximum friction occurs when the sliding direction is perpendicular to the backbone. We propose that the backbones impose anisotropic packing of the hydrocarbon side chains which leads to the observed friction anisotropy. Friction anisotropy is therefore a sensitive, optically-independent indicator of polymer backbone direction and monolayer structural properties

R and D options for demand side management in Japanese electric utilities

International Nuclear Information System (INIS)

Yamamoto, Takahiko

1996-01-01

Japanese electric demand has been steadily increasing in accordance with the economic growth. However, Japanese electric utilities are facing several problems; increasing construction cost of power facilities, siting constraints and the environmental issue of greenhouse gas emissions. To overcome these problems, electric utilities have been promoting demand-side-management (DSM) activities as well as supplier-side measures, with some presently being carried out through promoting energy conservation technologies and introducing electric tariff options of specific contracts for residential/commercial and industrial consumers. Japanese electric utilities have been carrying out R and D for the future, in particular, energy storage and heat storage which contribute to the improvement of load factor. In this paper, I would like to outline the R and D options for DSM in Japan. (author)

A distributed algorithm for demand-side management: Selling back to the grid.

Science.gov (United States)

Latifi, Milad; Khalili, Azam; Rastegarnia, Amir; Zandi, Sajad; Bazzi, Wael M

2017-11-01

Demand side energy consumption scheduling is a well-known issue in the smart grid research area. However, there is lack of a comprehensive method to manage the demand side and consumer behavior in order to obtain an optimum solution. The method needs to address several aspects, including the scale-free requirement and distributed nature of the problem, consideration of renewable resources, allowing consumers to sell electricity back to the main grid, and adaptivity to a local change in the solution point. In addition, the model should allow compensation to consumers and ensurance of certain satisfaction levels. To tackle these issues, this paper proposes a novel autonomous demand side management technique which minimizes consumer utility costs and maximizes consumer comfort levels in a fully distributed manner. The technique uses a new logarithmic cost function and allows consumers to sell excess electricity (e.g. from renewable resources) back to the grid in order to reduce their electric utility bill. To develop the proposed scheme, we first formulate the problem as a constrained convex minimization problem. Then, it is converted to an unconstrained version using the segmentation-based penalty method. At each consumer location, we deploy an adaptive diffusion approach to obtain the solution in a distributed fashion. The use of adaptive diffusion makes it possible for consumers to find the optimum energy consumption schedule with a small number of information exchanges. Moreover, the proposed method is able to track drifts resulting from changes in the price parameters and consumer preferences. Simulations and numerical results show that our framework can reduce the total load demand peaks, lower the consumer utility bill, and improve the consumer comfort level.

Accurate Estimation of Target amounts Using Expanded BASS Model for Demand-Side Management

Science.gov (United States)

Kim, Hyun-Woong; Park, Jong-Jin; Kim, Jin-O.

2008-10-01

The electricity demand in Korea has rapidly increased along with a steady economic growth since 1970s. Therefore Korea has positively propelled not only SSM (Supply-Side Management) but also DSM (Demand-Side Management) activities to reduce investment cost of generating units and to save supply costs of electricity through the enhancement of whole national energy utilization efficiency. However study for rebate, which have influence on success or failure on DSM program, is not sufficient. This paper executed to modeling mathematically expanded Bass model considering rebates, which have influence on penetration amounts for DSM program. To reflect rebate effect more preciously, the pricing function using in expanded Bass model directly reflects response of potential participants for rebate level.

Demand-side management and European environmental and energy goals: An optimal complementary approach

International Nuclear Information System (INIS)

Bergaentzlé, Claire; Clastres, Cédric; Khalfallah, Haikel

2014-01-01

Demand side management (DSM) in electricity markets could improve energy efficiency and achieve environmental targets through controlled consumption. For the past 10 years or so DSM programmes have registered significant results. However, detailed analysis of its real impact as observed by a large number of pilot studies suggests that such programmes need to be fine-tuned to suit clearly identified conditions. This study aims to provide recommendations for the instruments to be used to prompt demand response with a view to maximizing energy and environmental efficiencies of various countries. The present study suggests that different DSM models should be deployed depending on the specific generation mix in any given country. Beside the natural benefits from cross-borders infrastructures, DSM improves the flexibility and reliability of the energy system, absorbing some shock on generation mix. We show efficiency increases with demand response but at a decreasing rate. So, according to rebound and report effects, simple DSM tools could be preferred. - Highlights: • Demand side management could improve energy and environmental efficiency. • Several instruments should be used to achieve significant load-shedding. • DSM models should be deployed depending on generation mix. • Efficiency increases with demand response but at a decreasing rate. • Rebound and report effects reduce positive impacts

Modulation strategies of integrated HVAC systems used in residential buildings for demand-side management at different scales

OpenAIRE

Georges, Emeline

2017-01-01

The integration of renewable energy sources in the electricity production mix has an important impact on the management of the electricity grid, due to their intermittency. In particular, to ensure grid balancing, there is a rising need for flexibility, both on the supply and demand sides. A possible solution to help achieve grid balancing is the smart modulation of the electrical load in a "demand following supply" scheme through demand-side management. In this context, the objective of...

Optimal Multi-scale Demand-side Management for Continuous Power-Intensive Processes

Science.gov (United States)

Mitra, Sumit

With the advent of deregulation in electricity markets and an increasing share of intermittent power generation sources, the profitability of industrial consumers that operate power-intensive processes has become directly linked to the variability in energy prices. Thus, for industrial consumers that are able to adjust to the fluctuations, time-sensitive electricity prices (as part of so-called Demand-Side Management (DSM) in the smart grid) offer potential economical incentives. In this thesis, we introduce optimization models and decomposition strategies for the multi-scale Demand-Side Management of continuous power-intensive processes. On an operational level, we derive a mode formulation for scheduling under time-sensitive electricity prices. The formulation is applied to air separation plants and cement plants to minimize the operating cost. We also describe how a mode formulation can be used for industrial combined heat and power plants that are co-located at integrated chemical sites to increase operating profit by adjusting their steam and electricity production according to their inherent flexibility. Furthermore, a robust optimization formulation is developed to address the uncertainty in electricity prices by accounting for correlations and multiple ranges in the realization of the random variables. On a strategic level, we introduce a multi-scale model that provides an understanding of the value of flexibility of the current plant configuration and the value of additional flexibility in terms of retrofits for Demand-Side Management under product demand uncertainty. The integration of multiple time scales leads to large-scale two-stage stochastic programming problems, for which we need to apply decomposition strategies in order to obtain a good solution within a reasonable amount of time. Hence, we describe two decomposition schemes that can be applied to solve two-stage stochastic programming problems: First, a hybrid bi-level decomposition scheme with

Deep Neural Network Based Demand Side Short Term Load Forecasting

Directory of Open Access Journals (Sweden)

Seunghyoung Ryu

2016-12-01

Full Text Available In the smart grid, one of the most important research areas is load forecasting; it spans from traditional time series analyses to recent machine learning approaches and mostly focuses on forecasting aggregated electricity consumption. However, the importance of demand side energy management, including individual load forecasting, is becoming critical. In this paper, we propose deep neural network (DNN-based load forecasting models and apply them to a demand side empirical load database. DNNs are trained in two different ways: a pre-training restricted Boltzmann machine and using the rectified linear unit without pre-training. DNN forecasting models are trained by individual customer’s electricity consumption data and regional meteorological elements. To verify the performance of DNNs, forecasting results are compared with a shallow neural network (SNN, a double seasonal Holt–Winters (DSHW model and the autoregressive integrated moving average (ARIMA. The mean absolute percentage error (MAPE and relative root mean square error (RRMSE are used for verification. Our results show that DNNs exhibit accurate and robust predictions compared to other forecasting models, e.g., MAPE and RRMSE are reduced by up to 17% and 22% compared to SNN and 9% and 29% compared to DSHW.

Demand side management. Benefits and challenges

International Nuclear Information System (INIS)

Strbac, Goran

2008-01-01

In this paper, the major benefits and challenges of electricity demand side management (DSM) are discussed in the context of the UK electricity system. The relatively low utilisation of generation and networks (of about 50%) means that there is significant scope for DSM to contribute to increasing the efficiency of the system investment. The importance of the diversity of electricity load is discussed and the negative effects of DSM on load diversity illustrated. Ageing assets, the growth in renewable and other low-carbon generation technologies and advances in information and communication technologies are identified as major additional drivers that could lead to wider applications of DSM in the medium term. Potential benefits of DSM are discussed in the context of generation and of transmission and distribution networks. The provision of back-up capacity by generation may not be efficient as it will be needed relatively infrequently, and DSM may be better placed to support security. We also present an analysis of the value of DSM in balancing generation and demand in a future UK electricity system with significant variable renewable generation. We give a number of reasons for the relatively slow uptake of DSM, particularly in the residential, commercial and small business sectors. They include a lack of metering, information and communication infrastructure, lack of understanding of the benefits of DSM, problems with the competitiveness of DSM when compared with traditional approaches, an increase in the complexity of system operation and inappropriate market incentives. (author)

Indirect Control for Demand Side Management – A Conceptual Introduction

DEFF Research Database (Denmark)

Heussen, Kai; You, Shi; Biegel, Benjamin

2012-01-01

The concept of “indirect control” has become a relevant discussion term in relation to activation distributed and small-scale demand and generation units to provide resources for power system balancing. The term and its association with price signals has, however caused some confusion as to its...... correct definition, either as a control or a market concept. This paper aims to provide a conceptual introduction to "indirect control" for management of small and distributed demand side resources. A review of control concepts and an analysis of "indirectness" features are provided to create a framework...... for systematic classification of indirect control strategies. The concepts developed then enable a discussion of control performance and valuation of direct- and indirect control strategies....

A distributed algorithm for demand-side management: Selling back to the grid

Directory of Open Access Journals (Sweden)

Milad Latifi

2017-11-01

Full Text Available Demand side energy consumption scheduling is a well-known issue in the smart grid research area. However, there is lack of a comprehensive method to manage the demand side and consumer behavior in order to obtain an optimum solution. The method needs to address several aspects, including the scale-free requirement and distributed nature of the problem, consideration of renewable resources, allowing consumers to sell electricity back to the main grid, and adaptivity to a local change in the solution point. In addition, the model should allow compensation to consumers and ensurance of certain satisfaction levels. To tackle these issues, this paper proposes a novel autonomous demand side management technique which minimizes consumer utility costs and maximizes consumer comfort levels in a fully distributed manner. The technique uses a new logarithmic cost function and allows consumers to sell excess electricity (e.g. from renewable resources back to the grid in order to reduce their electric utility bill. To develop the proposed scheme, we first formulate the problem as a constrained convex minimization problem. Then, it is converted to an unconstrained version using the segmentation-based penalty method. At each consumer location, we deploy an adaptive diffusion approach to obtain the solution in a distributed fashion. The use of adaptive diffusion makes it possible for consumers to find the optimum energy consumption schedule with a small number of information exchanges. Moreover, the proposed method is able to track drifts resulting from changes in the price parameters and consumer preferences. Simulations and numerical results show that our framework can reduce the total load demand peaks, lower the consumer utility bill, and improve the consumer comfort level. Keywords: Energy, Systems engineering, Electrical engineering

THE TECHNOLOGY ASSESSMENT OF DEMAND SIDE BIDDING IN THE SOUTH AFRICAN CONTEXT*

Directory of Open Access Journals (Sweden)

H.K. Grover

2012-01-01

Full Text Available

ENGLISH ABSTRACT:South Africa is currently in the grip of a severe power supply capacity constraint. January 2007 saw blackouts throughout the country, and worse was expected in the months to come. As a measure of immediate remedy Eskom has turned to demand side bidding (DSB, a methodology whereby the demand side has an opportunity to sell back flexible load to the supply side. This paper assesses DSB with the aim of evaluating and gauging the current and potential future standing of DSB as a technology product within the South African context.

AFRIKAANSE OPSOMMING: Suid-Afrika ervaar tans ’n ernstige vraagstuk in elektrisiteitsvoorsiening. Vanaf Januarie 2007 kom gereelde kragonderbrekings voor, en volgens alle aanduidings lê die ergste nog voor. As ’n korttermynmaatreël beoog ESKOM ’n strategie van aanvraagbestuur en spesifiek aanvraag-bie, ’n metodologie waarvolgens verbruikers die geleentheid kry om elektrisiteit aan die verskaffer terug te verkoop. Hierdie artikel assesseer die metodologie ten einde die huidige en toekomstige gebruikersmoontlikhede daarvan as ’n tegnologieproduk binne Suid-Afrikaanse konteks te bepaal.

Demand Side Management for the European Supergrid: Occupancy variances of European single-person households

International Nuclear Information System (INIS)

Torriti, Jacopo

2012-01-01

The prospect of a European Supergrid calls for research on aggregate electricity peak demand and Europe-wide Demand Side Management. No attempt has been made as yet to represent a time-related demand curve of residential electricity consumption at the European level. This article assesses how active occupancy levels of single-person households vary in single-person household in 15 European countries. It makes use of occupancy time-series data from the Harmonised European Time Use Survey database to build European occupancy curves; identify peak occupancy periods; construct time-related electricity demand curves for TV and video watching activities and assess occupancy variances of single-person households. - Highlights: ► Morning peak occupancies of European single households tale place between 7h30 and 7h40. ► Evening peaks take place between 20h10 and 20h20. ► TV and video activities during evening peaks make up about 3.1 GWh of European peak electricity load. ► Baseline and peak occupancy variances vary across countries. ► Baseline and peak occupancy variances can be used as input for Demand Side Management choices.

Research on Simulation Requirements and Business Architecture of Automated Demand Response in Power Sales Side Market Liberalization

Science.gov (United States)

Liu, Yiqun; Zhou, Pengcheng; Zeng, Ming; Chen, Songsong

2018-01-01

With the gradual reform of the electricity market, the power sale side liberalization has become the focus of attention as the key task of reform. The open power market provides a good environment for DR (Demand Response). It is of great significance to research the simulation requirements and business architecture of ADR (Automatic Demand Response) in power sale side market liberalization. Firstly, this paper analyzes the simulation requirements of ADR. Secondly, it analyzes the influence factors that the business development of ADR from five aspects after power sale side market liberalization. Finally, Based on ADR technology support system, the business architecture of ADR after power sale side market liberalization is constructed.

The Demand Side Response to Multi-zone Tariffs. Consumer Test Results

Directory of Open Access Journals (Sweden)

Adam Olszewski

2015-12-01

Full Text Available Advanced Metering Infrastructure (AMI is a technologically advanced solution currently implemented by the most innovative distribution system operators. ENERGA-OPERATOR SA set about preparing for smart metering implementation in 2010. So far the company has installed over 400,000 meters in its area, and plans to install a further 450,000 in 2015. Kalisz, the first fully AMI-covered city in Poland, was chosen for an in-depth analysis of the system. In particular, a consumer test was conducted there with the intention of answering the question about the strength of the demand side response to multi-zone tariffs and power reduction. Conclusions from the year-long test show the demand side response to multi-zone tariffs – i.e. the maximum temporary percentage reduction of energy consumption in the time zone with the tariff raised by a min. of 80% – stays within the 5–15% range. In the case of power reduction (the maximum temporary reduction of energy consumption in the time zone when the power available to a household is limited to 1 kW – the demand side response stays within the 10–30% range. An additional effect of tariff diversification and smart metering is a reduction in electricity consumption by 1–4% on working days (i.e. this is the effect of either the consumption reduction or shifting it to weekends. During the test energy consumers were subjected to both price incentives and education. Due to the fact that it is difficult to separate the effects of education and tariff structures, the company plans to continue the research related to verifying the effectiveness of individual activation tools in reducing electricity consumption by households.

Generation of flexible domestic load profiles to evaluate demand side management approaches

NARCIS (Netherlands)

Hoogsteen, Gerwin; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria

2016-01-01

Various Demand Side Management (DSM) approaches have been developed the last couple of years to avoid costly grid upgrades. However, evaluation of these DSM methodologies is usually restricted to a use-case specific example, making comparison between different DSM approaches hard. This paper

A System Architecture for Autonomous Demand Side Load Management in Smart Buildings

DEFF Research Database (Denmark)

Costanzo, Giuseppe Tommaso; Zhu, Guchuan; Anjos, Miguel F.

2012-01-01

This paper presents a system architecture for load management in smart buildings which enables autonomous demand side load management in the smart grid. Being of a layered structure composed of three main modules for admission control, load balancing, and demand response management...... in multiple time-scales and allows seamless integration of diverse techniques for online operation control, optimal scheduling, and dynamic pricing. The design of a home energy manager based on this architecture is illustrated and the simulation results with Matlab/Simulink confirm the viability...

A Brief Introduction to the Theory of Friction Stir Welding

Science.gov (United States)

Nunes, Arthur C., Jr.

2008-01-01

Friction stir welding (FSW) is a solid state welding process invented in 1991 at The Welding Institute in the United Kingdom. A weld is made in the FSW process by translating a rotating pin along a weld seam so as to stir the sides of the seam together. FSW avoids deleterious effects inherent in melting and is already an important welding process for the aerospace industry, where welds of optimal quality are demanded. The structure of welds determines weld properties. The structure of friction stir welds is determined by the flow field in the weld metal in the vicinity of the weld tool. A simple kinematic model of the FSW flow field developed at Marshall Space Flight Center, which enables the basic features of FSW microstructure to be understood and related to weld process parameters and tool design, is explained.

Renewable generation versus demand-side management. A comparison for the Spanish market

International Nuclear Information System (INIS)

Roldán Fernández, Juan Manuel; Burgos Payán, Manuel; Riquelme Santos, Jesús Manuel; Trigo García, Ángel Luis

2016-01-01

Conventionally the required instantaneous balance generation-load is achieved by adjusting production to fit variable consumer demand. Nowadays, a significant and increasing segment of generation is renewable. But renewable production cannot be scheduled on request since its generation is dependent on nature (wind, sun, …). In this context, demand-side management (DSM) would help since it would be advisable for part of the flexibility to be provided by the demand. The integration of renewable production and demand-side management (DSM), are compared in this work for Spain throughout 2008–2014. First a qualitative model, based on the linearization of the wholesale market, is employed to explore some hypotheses. A set of scenarios are then examined to quantify the main effects on the market. The results show that DSM exhibits the best performance in terms of economic efficiency and environmental sustainability, as well as for the reduction of load peaks and losses in the system, what suggests the convenience of promoting plans for the replacement of equipment with other more efficient as well as the implementation of real-time tariffs. - Highlights: •The impact of the integration of renewable production versus DSM has been compared. •Merit-order effect related to energy efficiency and to load-shifting is identified. •Large industries achieve energy efficiency with less CAPEX than renewable generation. •Load-shifting cycle yields a reduction of the traded energy and the economic volume.

R and D options for demand side management in Japanese electric utilities

International Nuclear Information System (INIS)

Yamamoto, T.

1995-01-01

Japanese electric utilities are facing several problems: increasing construction cost of power facilities, siting constraints and the environmental issue of greenhouse gas emissions. To overcome these problems, electric utilities have been promoting demand-side-management (DSM) activities as well as supplier-side measures, with some presently being carried out through promoting energy conservation technologies and introducing tariff options for residential/commercial and industrial consumers. R and D works have been carried out on various fields such as energy storage and heat storage which contribute to the improvement of the load factor. 5 figs., 2 tabs

Demand-side management and demand response in the Ontario energy sectors

International Nuclear Information System (INIS)

2004-01-01

A directive from the former Minister of Energy was received by the Ontario Energy Board (OEB), directing the Board to consult with stakeholders on options for the delivery of demand-side management (DSM) and demand response (DR) activities within the electricity sector, including the role of local distribution companies in such activities. The implementation costs were to be balanced with the benefits to both consumers and the entire system. The scope of the review was expanded by the Board to include the role of gas distribution companies in DSM. A consultation process was implemented and stakeholders were invited to participate. A series of recommendations was made, including: (1) a hybrid framework utilizing market-based and public-policy approaches should deliver DSM and DR activities in Ontario's energy markets, (2) DSM and DR activities should come under the responsibility of a central agency, (3) DSM and DR activities should be coordinated through cooperation between the Ministry of Energy, the Independent Electricity Market Operator (IMO) and the Ontario Energy Board, (4) regulatory mechanisms to induce gas distributors, electricity transmitters and electricity distributors to reduce distribution system losses should be put in place, (5) all electricity consumers should fund electricity DSM and some retail DR initiatives through a transparent, non-bypassable consumption charge, and (6) the Board should design, develop and deliver information to consumers regarding energy conservation, energy efficiency, load management, and cleaner sources of energy. refs., 4 figs

Electronic Health Records Prospects in Egypt: A Demand-Side Perspective

OpenAIRE

Badran; Mona Farid

2017-01-01

The present study sheds light on the expected factors that would impact the Electronic Health Records (EHR) service in Egypt from the demand-side perspective, i.e. the health care consumer. This empirical study is motivated by the widespread use of EHR as a method of promoting health services globally, where it is considered as an efficiency enhancing, cost effective technology. Moreover, the healthcare sector in Egypt is gaining momentum, especially that the comprehensive healthcare and soci...

Evaluation of demand-side management programs

International Nuclear Information System (INIS)

Kolbe, A.L.; O'Loughlin, M.P.

1990-01-01

Over the past few years, the attention accorded to demand-side management (DSM) measures has called into question the traditional cost minimization approach for evaluating such programs. Two broad approaches to DSM seem to be generally used: one examining the problem from multiple perspectives and the other including various practical methods used in-house by utility planners. Whatever the standard used to evaluate DSM, there remains at least one problem which cannot be quantified. The customers who participate in a DSM program cannot only take into account the effects of DSM on their electricity bills; their comfort can also be affected. This lowering of comfort constitutes a legitimate cost which can explain why some apparently sensible DSM measures are not adopted. A method is proposed to incorporate this cost. It establishes a way to evaluate DSM program tradeoffs that, from the perspective of standard economic theory, maximizes social welfare; explains why at least one of the perspectives in the multiple perspective approach needs to be modified to incorporate all customer costs; and outlines how the proposed standard can be implemented. 8 refs

Electricity decision-making: New techniques for calculating statewide economic impacts from new power supply and demand-side management programs

Science.gov (United States)

Tegen, Suzanne Isabel Helmholz

This dissertation introduces new techniques for calculating and comparing statewide economic impacts from new coal, natural gas and wind power plants, as well as from demand-side management programs. The impetus for this work was two-fold. First, reviews of current literature and projects revealed that there was no standard way to estimate statewide economic impacts from new supply- and demand-side electricity options. Second, decision-makers who were interviewed stated that they were overwhelmed with data in general, but also lacked enough specific information about economic development impacts to their states from electricity, to make informed choices. This dissertation includes chapters on electricity decision-making and on economic impacts from supply and demand. The supply chapter compares different electricity options in three states which vary in natural resource content: Arizona, Colorado and Michigan. To account for differing capacity factors, resources are compared on a per-megawatt-hour basis. The calculations of economic impacts from new supply include: materials and labor for construction, operations, maintenance, fuel extraction, fuel transport, as well as property tax, financing and landowner revenues. The demand-side chapter compares residential, commercial and industrial programs in Iowa. Impact calculations include: incremental labor and materials for program planning, installation and operations, as well as sales taxes and electricity saved. Results from supply-side calculations in the three states analyzed indicate that adding new wind power can have a greater impact to a state's economy than adding new gas or coal power due to resource location, taxes and infrastructure. Additionally, demand-side management programs have a higher relative percentage of in-state dollar flow than supply-side solutions, though demand-side programs typically involve fewer MWh and dollars than supply-side generation. Methods for this dissertation include researching

Promoting healthcare innovation on the demand side

Science.gov (United States)

Eisenberg, Rebecca S.

2017-01-01

Abstract Innovation policy often focuses on fortifying the incentives of firms that develop and sell new products by offering them lucrative rights to exclude competitors from the market. Regulators also rely on these same firms—and on similar incentives—to develop information about the effects of their products in patients, despite their obvious conflict of interest. The result may be a distorted understanding that leads to overuse of expensive new medical technologies. Recent technological advances have put healthcare payers in an excellent position to play a larger role in future innovation to improve healthcare and reduce its costs. Insurance companies and integrated healthcare providers have custody of treasure troves of data about healthcare provision and outcomes that can yield valuable insights about the effects of medical treatment without the need to conduct costly clinical trials. Some integrated healthcare systems have seized upon this advantage to make notable discoveries about the effects of particular products that have changed the standard of care. Moreover, to the extent that healthcare payers can profit from reducing costs, they will seek to avoid inappropriate use of costly technologies. Greater involvement of payers in healthcare innovation thus offers a potential counterweight to the incentives of product sellers to promote excessive use of costly new products. In recent years, the federal government has sought to promote innovation through analysis of healthcare records in a series of initiatives; some picture insurers as passive data repositories, while others provide opportunities for insurers to take a more active role in innovation. In this paper, we examine the role of health insurers in developing new knowledge about the provision and effects of healthcare—what we call ‘demand-side innovation’. We address the contours of this underexplored area of innovation and describe the behavior of participating firms. We examine the

US EPA's photovoltaic demand-side management project. Report for September 1992-July 1993

International Nuclear Information System (INIS)

Kern, E.C.; Spiegel, R.J.

1993-01-01

The paper discusses an investigation of how photovoltaics (PV) may be used as both a pollution-mitigating energy replacement for fossil fuels and a demand-side management (DSM) option to reduce peak electrical demands of commercial and residential buildings. Eleven electric utilities are partners in this first nationwide demonstration of PV DSM. The approach is to install and monitor standardized PV systems in diverse geographic areas with varying solar energy resource and electric power demand, production, and cost conditions. The systems are being monitored for a year to record direct and diffuse irradiance, ambient air temperature, PV power generation, and building loads. Utilities are providing the electric system operations data needed to determine the pollution mitigation and peak demand reduction that can result from the PV electrical power generation

Demand side management in households. Potentials and restraints of short-term power supply; Demand Side Management in Haushalten. Potenziale und Hemmnisse fuer kurzfristige Leistungsbereitstellung

Energy Technology Data Exchange (ETDEWEB)

Roon, Serafin von; Gobmaier, Thomas [FfE Forschungsstelle fuer Energiewirtschaft e.V., Muenchen (Germany); Huck, Malte

2010-07-01

Within the project ''Wind energy - balancing forecast errors'' we examine potentials, restraints and costs of various options for balancing forecast errors of wind power generation. One possibility of providing this backup power could be to practice Demand Side Management (DSM) of household appliances. The integration of these appliances in a DSM network is facilitated by standardized data transmission procedures and the increasing deployment of microprocessors. Due to the low power consumption of the switchable devices no DSM measures are implemented in the household sector so far, despite the numerous appliances. (orig.)

Distributed Demand Side Management with Battery Storage for Smart Home Energy Scheduling

Directory of Open Access Journals (Sweden)

Omowunmi Mary Longe

2017-01-01

Full Text Available The role of Demand Side Management (DSM with Distributed Energy Storage (DES has been gaining attention in recent studies due to the impact of the latter on energy management in the smart grid. In this work, an Energy Scheduling and Distributed Storage (ESDS algorithm is proposed to be installed into the smart meters of Time-of-Use (TOU pricing consumers possessing in-home energy storage devices. Source of energy supply to the smart home appliances was optimized between the utility grid and the DES device depending on energy tariff and consumer demand satisfaction information. This is to minimize consumer energy expenditure and maximize demand satisfaction simultaneously. The ESDS algorithm was found to offer consumer-friendly and utility-friendly enhancements to the DSM program such as energy, financial, and investment savings, reduced/eliminated consumer dissatisfaction even at peak periods, Peak-to-Average-Ratio (PAR demand reduction, grid energy sustainability, socio-economic benefits, and other associated benefits such as environmental-friendliness.

Market modeling for assessment of demand side programs using the marginal cost

International Nuclear Information System (INIS)

Papastamatiou, Panagiotis; Psarras, John

2000-01-01

Demand side management is nowadays considered as a functional step in the energy planning process. The criteria proposed for the assessment of the demand side programs (DSPs) are usually based on the balance between the marginal supply cost and the mean DSP cost. These criteria could not support the allotting of the invested capital to incentives for the consumers and advertising. This paper presents a methodology to support the utility planning at this point with more reliability. It proposes the expansion of the assessment criteria with the use of the marginal cost of the DSP. For the calculation of the DSP marginal cost, a dynamic model is developed and it is used for the simulation of the penetration of a DS Program. Using the 'least-cost' criterion as the decision rule for the simulation, the planner has a distribution of the available investment capital throughout the whole planning period. The use of the 'most-value' criterion supports the separation of the invested capital between incentives for the consumers and supportive expenses, e.g. advertising, marketing cost, etc. (Author)

Integrating Demand-Side Resources into the Electric Grid: Economic and Environmental Considerations

Science.gov (United States)

Fisher, Michael J.

Demand-side resources are taking an increasingly prominent role in providing essential grid services once provided by thermal power plants. This thesis considers the economic feasibility and environmental effects of integrating demand-side resources into the electric grid with consideration given to the diversity of market and environmental conditions that can affect their behavior. Chapter 2 explores the private economics and system-level carbon dioxide reduction when using demand response for spinning reserve. Steady end uses like lighting are more than twice as profitable as seasonal end uses because spinning reserve is needed year-round. Avoided carbon emission damages from using demand response instead of fossil fuel generation for spinning reserve are sufficient to justify incentives for demand response resources. Chapter 3 quantifies the system-level net emissions rate and private economics of behind-the-meter energy storage. Net emission rates are lower than marginal emission rates for power plants and in-line with estimates of net emission rates from grid-level storage. The economics are favorable for many buildings in regions with high demand charges like California and New York, even without subsidies. Future penetration into regions with average charges like Pennsylvania will depend greatly on installation cost reductions and wholesale prices for ancillary services. Chapter 4 outlines a novel econometric model to quantify potential revenues from energy storage that reduces demand charges. The model is based on a novel predictive metric that is derived from the building's load profile. Normalized revenue estimates are independent of the power capacity of the battery holding other performance characteristics equal, which can be used to calculate the profit-maximizing storage size. Chapter 5 analyzes the economic feasibility of flow batteries in the commercial and industrial market. Flow batteries at a 4-hour duration must be less expensive on a dollar per

Demand-side management pricing options in electric utilities

International Nuclear Information System (INIS)

Sardana, P.; Herman, P.

1990-01-01

In 1989 Ontario Hydro implemented optional time-of-use (TOU) rates at the wholesale level for all municipal utilities in the province. At the same time, mandatory TOU rates were implemented for large users (customers with loads in excess of 5 MW) served by municipal utilities and Ontario Hydro's direct customers. To fully explore the potential of rate structures as demand-side management (DSM) tools, Ontario Hydro retained a consulting firm to carry out a survey of innovative rate structures in other jurisdications. The survey was intended to identify: the status quo of rate structures in other jurisdictions that were designed specifically to encourage DSM; a profile of the cost basis of the rate structures, for example whether traditional embedded cost of service analyses or contentious methods such as marginal cost pricing were used; whether innovative rates have been successful, and customer reactions and attitudes; and how innovative rates fit into the overall strategy of the utilities. It was found that TOU, interruptible and end-use targeted rates are the rate structures of choice for many utilities. Most are concerned with deferring capacity, reducing peak demand, and shifting load out of peak periods. Most utilities report success with their programs and satisfaction with the present form of the programs. 5 tabs

High Friction Surface Treatments, Transportation Research Synthesis

Science.gov (United States)

2018-03-01

MnDOT and local transportation agencies in Minnesota are considering the use of a high friction surface treatment (HFST) as a safety strategy. HFST is used as a spot pavement surfacing treatment in locations with high friction demand (for example, cr...

Friction

Science.gov (United States)

Matsuo, Yoshihiro; Clarke, Daryl D.; Ozeki, Shinichi

Friction materials such as disk pads, brake linings, and clutch facings are widely used for automotive applications. Friction materials function during braking due to frictional resistance that transforms kinetic energy into thermal energy. There has been a rudimentary evolution, from materials like leather or wood to asbestos fabric or asbestos fabric saturated with various resins such as asphalt or resin combined with pitch. These efforts were further developed by the use of woven asbestos material saturated by either rubber solution or liquid resin binder and functioned as an internal expanding brake, similar to brake lining system. The role of asbestos continued through the use of chopped asbestos saturated by rubber, but none was entirely successful due to the poor rubber heat resistance required for increased speeds and heavy gearing demands of the automobile industry. The use of phenolic resins as binder for asbestos friction materials provided the necessary thermal resistance and performance characteristics. Thus, the utility of asbestos as the main friction component, for over 100 years, has been significantly reduced in friction materials due to asbestos identity as a carcinogen. Steel and other fibrous components have displaced asbestos in disk pads. Currently, non-asbestos organics are the predominate friction material. Phenolic resins continue to be the preferred binder, and increased amounts are necessary to meet the requirements of highly functional asbestos-free disk pads for the automotive industry. With annual automobile production exceeding 70 million vehicles and additional automobile production occurring in developing countries worldwide and increasing yearly, the amount of phenolic resin for friction material is also increasing (Fig. 14.1). Fig. 14.1 Worldwide commercial vehicle production In recent years, increased fuel efficiency of passenger car is required due to the CO2 emission issue. One of the solutions to improve fuel efficiency is to

Friction Stir Welding

Science.gov (United States)

Nunes, Arthur C., Jr.

2008-01-01

Friction stir welding (FSW) is a solid state welding process invented in 1991 at The Welding Institute in the United Kingdom. A weld is made in the FSW process by translating a rotating pin along a weld seam so as to stir the sides of the seam together. FSW avoids deleterious effects inherent in melting and promises to be an important welding process for any industries where welds of optimal quality are demanded. This article provides an introduction to the FSW process. The chief concern is the physical effect of the tool on the weld metal: how weld seam bonding takes place, what kind of weld structure is generated, potential problems, possible defects for example, and implications for process parameters and tool design. Weld properties are determined by structure, and the structure of friction stir welds is determined by the weld metal flow field in the vicinity of the weld tool. Metal flow in the vicinity of the weld tool is explained through a simple kinematic flow model that decomposes the flow field into three basic component flows: a uniform translation, a rotating solid cylinder, and a ring vortex encircling the tool. The flow components, superposed to construct the flow model, can be related to particular aspects of weld process parameters and tool design; they provide a bridge to an understanding of a complex-at-first-glance weld structure. Torques and forces are also discussed. Some simple mathematical models of structural aspects, torques, and forces are included.

An Integrated Decentralized Energy Planning Model considering Demand-Side Management and Environmental Measures

Directory of Open Access Journals (Sweden)

Seyed Mahmood Kazemi

2013-01-01

Full Text Available Decentralized energy planning (DEP is looked upon as an indisputable opportunity for energy planning of villages, isolated islands, and far spots. Nonetheless, at this decentralized planning level, the value of demand-side resources is not fairly examined, despite enjoying great advantages. Therefore, the core task of this study is to integrate demand-side resources, as a competing solution against supply-side alternatives, with decentralized energy planning decisions and demonstrate the rewarding role it plays. Moreover, sustainability indicators (SIs are incorporated into DEP attempts in order to attain sustainable development. It is emphasized that unless these indicators are considered at lower energy planning levels, they will be ignored at higher planning levels as well. Hence, to the best knowledge of the authors, this study for the first time takes into account greenhouse gas (GHG emissions produced by utilization of renewable energies in DEP optimization models. To address the issues mentioned previously, multiobjective linear programming model along with a min-max goal programming approach is employed. Finally, using data taken from the literature, the model is solved, and the obtained results are discussed. The results show that DSM policies have remarkably contributed to significant improvements especially in terms of environmental indicators.

A novel microgrid demand-side management system for manufacturing facilities

Science.gov (United States)

Harper, Terance J.

Thirty-one percent of annual energy consumption in the United States occurs within the industrial sector, where manufacturing processes account for the largest amount of energy consumption and carbon emissions. For this reason, energy efficiency in manufacturing facilities is increasingly important for reducing operating costs and improving profits. Using microgrids to generate local sustainable power should reduce energy consumption from the main utility grid along with energy costs and carbon emissions. Also, microgrids have the potential to serve as reliable energy generators in international locations where the utility grid is often unstable. For this research, a manufacturing process that had approximately 20 kW of peak demand was matched with a solar photovoltaic array that had a peak output of approximately 3 KW. An innovative Demand-Side Management (DSM) strategy was developed to manage the process loads as part of this smart microgrid system. The DSM algorithm managed the intermittent nature of the microgrid and the instantaneous demand of the manufacturing process. The control algorithm required three input signals; one from the microgrid indicating the availability of renewable energy, another from the manufacturing process indicating energy use as a percent of peak production, and historical data for renewable sources and facility demand. Based on these inputs the algorithm had three modes of operation: normal (business as usual), curtailment (shutting off non-critical loads), and energy storage. The results show that a real-time management of a manufacturing process with a microgrid will reduce electrical consumption and peak demand. The renewable energy system for this research was rated to provide up to 13% of the total manufacturing capacity. With actively managing the process loads with the DSM program alone, electrical consumption from the utility grid was reduced by 17% on average. An additional 24% reduction was accomplished when the microgrid

Intelligent demand side management of residential building energy systems

Science.gov (United States)

Sinha, Maruti N.

Advent of modern sensing technologies, data processing capabilities and rising cost of energy are driving the implementation of intelligent systems in buildings and houses which constitute 41% of total energy consumption. The primary motivation has been to provide a framework for demand-side management and to improve overall reliability. The entire formulation is to be implemented on NILM (Non-Intrusive Load Monitoring System), a smart meter. This is going to play a vital role in the future of demand side management. Utilities have started deploying smart meters throughout the world which will essentially help to establish communication between utility and consumers. This research is focused on investigation of a suitable thermal model of residential house, building up control system and developing diagnostic and energy usage forecast tool. The present work has considered measurement based approach to pursue. Identification of building thermal parameters is the very first step towards developing performance measurement and controls. The proposed identification technique is PEM (Prediction Error Method) based, discrete state-space model. The two different models have been devised. First model is focused toward energy usage forecast and diagnostics. Here one of the novel idea has been investigated which takes integral of thermal capacity to identify thermal model of house. The purpose of second identification is to build up a model for control strategy. The controller should be able to take into account the weather forecast information, deal with the operating point constraints and at the same time minimize the energy consumption. To design an optimal controller, MPC (Model Predictive Control) scheme has been implemented instead of present thermostatic/hysteretic control. This is a receding horizon approach. Capability of the proposed schemes has also been investigated.

Advanced emergency braking under split friction conditions and the influence of a destabilising steering wheel torque

Science.gov (United States)

Tagesson, Kristoffer; Cole, David

2017-07-01

The steering system in most heavy trucks is such that it causes a destabilising steering wheel torque when braking on split friction, that is, different friction levels on the two sides of the vehicle. Moreover, advanced emergency braking systems are now mandatory in most heavy trucks, making vehicle-induced split friction braking possible. This imposes higher demands on understanding how the destabilising steering wheel torque affects the driver, which is the focus here. Firstly, an experiment has been carried out involving 24 subjects all driving a truck where automatic split friction braking was emulated. Secondly, an existing driver-vehicle model has been adapted and implemented to improve understanding of the observed outcome. A common conclusion drawn, after analysing results, is that the destabilising steering wheel torque only has a small effect on the motion of the vehicle. The underlying reason is a relatively slow ramp up of the disturbance in comparison to the observed cognitive delay amongst subjects; also the magnitude is low and initially suppressed by passive driver properties.

Friction Pull Plug and Material Configuration for Anti-Chatter Friction Pull Plug Weld

Science.gov (United States)

Littell, Justin Anderson (Inventor)

2016-01-01

A friction pull plug is provided for use in forming a plug weld in a hole in a material. The friction pull plug includes a shank and a series of three frustoconical sections. The relative sizes of the sections assure that a central one of the sections defines the initial contact point between the hole's sides. The angle defined by the central one of the sections reduces or eliminates chatter as the plug is pulled into the hole.

Comparing Demand Side Management approaches

NARCIS (Netherlands)

Molderink, Albert; Bakker, Vincent; Hurink, Johann L.; Smit, Gerardus Johannes Maria

2012-01-01

Due to increasing energy prices and the greenhouse effect, a more efficient energy supply is desirable, preferably based on renewable sources. To cope with the decrease of flexibility due to the introduction of renewables in production side of the supply chain, a more flexible consumer side is

Development of planning methods for demand-side management (DSM)

International Nuclear Information System (INIS)

Kaerkkaeinen, S.; Kekkonen, V.; Rissanen, P.

1995-01-01

The interest of utilities and governmental agencies in Demand-side management (IDSM) and Integrated Resource Planning (IRP) has increased during recent years also in Finland. From the governmental point of view, the main reason for this has been concern about the environmental effects of electricity supply and consumption. Utilities are mainly interested in cost reductions in electricity supply and distribution caused by DSM. Also improved service to the customer due to DSM has increasing value to utilities. In this project, the main target has been to develop and assess methods for DSM planning from the utility point of view. The final goal is to integrate these methods into the strategic planning of electric utilities

Who should pay for demand-side management programs?

International Nuclear Information System (INIS)

Flaim, T.

1992-01-01

Traditional utility resource planning involves taking the load forecast as a given and then determining the additional supply resources expected to serve that load at minimum cost and optimal levels of reliability. With integrated planning, the goal is still to balance supply and demand, but in a way that is most cost effective given all possible ways to serve customers' energy service needs. The new element in integrated resource planning is demand side management (DSM) or activities aimed at altering the quantity of energy customers use and/or the timing of their consumption. This paper discusses how DSM works to accomplish energy conservation and how it affects the rate structure. It also goes on to discuss how a utility can optimize the participation in a conservation program so that no particular group might have to carry the brunt of a rate increase. These suggestions include aligning rates to accurately reflect marginal costs; require participating customers to pay as many program costs as are possible; where participating customers can't pay full cost of a program, restrict costs to those groups who are eligible to participate; and offer a 'reverse shared-savings' program to the largest customers. The paper goes on to discuss electric-to-gas fuel switching and what customers should carry the cost burden for this type of switching

Modeling Supermarket Refrigeration Systems for Demand-Side Management

Directory of Open Access Journals (Sweden)

Jakob Stoustrup

2013-02-01

Full Text Available Modeling of supermarket refrigeration systems for supervisory control in the smart grid is presented in this paper. A modular modeling approach is proposed in which each module is modeled and identified separately. The focus of the work is on estimating the power consumption of the system while estimating the cold reservoir temperatures as well. The models developed for each module as well as for the overall integrated system are validated by real data collected from a supermarket in Denmark. The results show that the model is able to estimate the actual electrical power consumption with a high fidelity. Moreover a simulation benchmark is introduced based on the produced model for demand-side management in smart grid. Finally, a potential application of the proposed benchmark in direct control of the power/energy consumption is presented by a simple simulation example.

Managing Sustainable Demand-side Infrastructure for Power System Ancillary Services

Science.gov (United States)

Parkinson, Simon Christopher

Widespread access to renewable electricity is seen as a viable method to mitigate carbon emissions, although problematic are the issues associated with the integration of the generation systems within current power system configurations. Wind power plants are the primary large-scale renewable generation technology applied globally, but display considerable short-term supply variability that is difficult to predict. Power systems are currently not designed to operate under these conditions, and results in the need to increase operating reserve in order to guarantee stability. Often, operating conventional generation as reserve is both technically and economically inefficient, which can overshadow positive benefits associated with renewable energy exploitation. The purpose of this thesis is to introduce and assess an alternative method of enhancing power system operations through the control of electric loads. In particular, this thesis focuses on managing highly-distributed sustainable demand-side infrastructure, in the form of heat pumps, electric vehicles, and electrolyzers, as dispatchable short-term energy balancing resources. The main contribution of the thesis is an optimal control strategy capable of simultaneously balancing grid- and demand-side objectives. The viability of the load control strategy is assessed through model-based simulations that explicitly track end-use functionality of responsive devices within a power systems analysis typically implemented to observe the effects of integrated wind energy systems. Results indicate that there is great potential for the proposed method to displace the need for increased reserve capacity in systems considering a high penetration of wind energy, thereby allowing conventional generation to operate more efficiently and avoid the need for possible capacity expansions.

Demand-side management: The perspective of a combination utility

International Nuclear Information System (INIS)

Packard, C.P.

1993-01-01

During the 1980's, Baltimore Gas ampersand Electric (BG ampersand E) met part of the rapid growth in demand for electricity in its service territory by implementing cost-effective demand-side management (DSM) programs--specifically, peak shaving and load shifting strategies. BG ampersand E's focus in the 1990's has been expanded to include all DSM options with an increasing emphasis on those which promote overall 1 energy efficiency or strategic conservation. This change in focus is being driven by Federal legislation, state regulatory requirements and the perceived potential benefits for both the customer and the Company. Current activities related to DSM include involvement in a Collaborative Process to design cost-effective electric and gas conservation programs for all customer classes--low-income, residential, commercial and industrial. Program design consists of four steps: (1) data gathering and technology assessment; (2) development of program concepts; (3) detailed program design and (4) monitoring and evaluation. Significant reductions in the projected peaks as well as in sales in future years are the anticipated results of our efforts. As a combination utility, unique opportunities and challenges face BG ampersand E: fuel switching, eligibility of non-full requirements customers, and energy options for customers

Hawaii demand-side management resource assessment. Final report: DSM opportunity report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-08-01

The Hawaii Demand-Side Management Resource Assessment was the fourth of seven projects in the Hawaii Energy Strategy (HES) program. HES was designed by the Department of Business, Economic Development, and Tourism (DBEDT) to produce an integrated energy strategy for the State of Hawaii. The purpose of Project 4 was to develop a comprehensive assessment of Hawaii`s demand-side management (DSM) resources. To meet this objective, the project was divided into two phases. The first phase included development of a DSM technology database and the identification of Hawaii commercial building characteristics through on-site audits. These Phase 1 products were then used in Phase 2 to identify expected energy impacts from DSM measures in typical residential and commercial buildings in Hawaii. The building energy simulation model DOE-2.1E was utilized to identify the DSM energy impacts. More detailed information on the typical buildings and the DOE-2.1E modeling effort is available in Reference Volume 1, ``Building Prototype Analysis``. In addition to the DOE-2.1E analysis, estimates of residential and commercial sector gas and electric DSM potential for the four counties of Honolulu, Hawaii, Maui, and Kauai through 2014 were forecasted by the new DBEDT DSM Assessment Model. Results from DBEDTs energy forecasting model, ENERGY 2020, were linked with results from DOE-2.1E building energy simulation runs and estimates of DSM measure impacts, costs, lifetime, and anticipated market penetration rates in the DBEDT DSM Model. Through its algorithms, estimates of DSM potential for each forecast year were developed. Using the load shape information from the DOE-2.1E simulation runs, estimates of electric peak demand impacts were developed. 10 figs., 55 tabs.

Demand-Side Energy Management Based on Nonconvex Optimization in Smart Grid

Directory of Open Access Journals (Sweden)

Kai Ma

2017-10-01

Full Text Available Demand-side energy management is used for regulating the consumers’ energy usage in smart grid. With the guidance of the grid’s price policy, the consumers can change their energy consumption in response. The objective of this study is jointly optimizing the load status and electric supply, in order to make a tradeoff between the electric cost and the thermal comfort. The problem is formulated into a nonconvex optimization model. The multiplier method is used to solve the constrained optimization, and the objective function is transformed to the augmented Lagrangian function without constraints. Hence, the Powell direction acceleration method with advance and retreat is applied to solve the unconstrained optimization. Numerical results show that the proposed algorithm can achieve the balance between the electric supply and demand, and the optimization variables converge to the optimum.

External Coulomb-Friction Damping For Hydrostatic Bearings

Science.gov (United States)

Buckmann, Paul S.

1992-01-01

External friction device damps vibrations of shaft and hydrostatic ring bearing in which it turns. Does not rely on wear-prone facing surfaces. Hydrostatic bearing ring clamped in radially flexing support by side plates clamped against radial surfaces by spring-loaded bolts. Plates provide friction against radial motions of shaft.

Innovation and Demand

DEFF Research Database (Denmark)

Andersen, Esben Sloth

2007-01-01

the demand-side of markets in the simplest possible way. This strategy has allowed a gradual increase in the sophistication of supply-side aspects of economic evolution, but the one-sided focus on supply is facing diminishing returns. Therefore, demand-side aspects of economic evolution have in recent years...... received increased attention. The present paper argues that the new emphasis on demand-side factors is quite crucial for a deepened understanding of economic evolution. The major reasons are the following: First, demand represents the core force of selection that gives direction to the evolutionary process....... Second, firms' innovative activities relate, directly or indirectly, to the structure of expected and actual demand. Third, the demand side represents the most obvious way of turning to the much-needed analysis of macro-evolutionary change of the economic system....

Development of assessment model for demand-side management investment programs in Korea

International Nuclear Information System (INIS)

Lee, Deok Ki; Park, Sang Yong; Park, Soo Uk

2007-01-01

The goal of this study is the development of the assessment model for demand-side management investment programs (DSMIPs) in the areas of natural gas and district heating. Demand-side management (DSM) is the process of managing the consumption of energy to optimize available and planned generation resources and DSMIPs are the actions conducted by energy suppliers to promote investment in the DSM. In this research, the analytic hierarchy process (AHP) method was used to develop a scientific and rational assessment model for DSMIPs. To apply the AHP method, assessment indicators for the assessment have been identified by using the concept of 'plan, do, see' and the decision-making hierarchy was established. Then AHP model was developed to set up the priorities of assessment indicators and a survey of experts from government and energy suppliers was carried out. Finally, the priorities of assessment indicators were calculated based on the result of survey using the AHP method. The assessment model developed from this research will actually be used to assess the results of DSMIPs, which is being carried out by Korea gas corporation (KOGAS) and Korea district heating corporation (KDHC). The use of the assessment model developed by this research is expected to contribute to enhance efficiency in planning, execution, and assessment of DSMIPs

Impacts of Demand-Side Management on Electrical Power Systems: A Review

Directory of Open Access Journals (Sweden)

Hussein Jumma Jabir

2018-04-01

Full Text Available Electricity demand has grown over the past few years and will continue to grow in the future. The increase in electricity demand is mainly due to industrialization and the shift from a conventional to a smart-grid paradigm. The number of microgrids, renewable energy sources, plug-in electric vehicles and energy storage systems have also risen in recent years. As a result, future electricity grids have to be revamped and adapt to increasing load levels. Thus, new complications associated with future electrical power systems and technologies must be considered. Demand-side management (DSM programs offer promising solutions to these issues and can considerably improve the reliability and financial performances of electrical power systems. This paper presents a review of various initiatives, techniques, impacts and recent developments of the DSM of electrical power systems. The potential benefits derived by implementing DSM in electrical power networks are presented. An extensive literature survey on the impacts of DSM on the reliability of electrical power systems is also provided for the first time. The research gaps within the broad field of DSM are also identified to provide directions for future work.

The energy efficiency and demand side management programs as implemented by the energy efficiency division of the department of energy

International Nuclear Information System (INIS)

Anunciacion, Jesus C.

1997-01-01

The thrust of the Philippine energy sector. specifically the government side, is to involve the active participation of not only all the government agencies involved in energy activities but the private sector as well. This participation shall mean technical and financial participation, directly and indirectly. The Department of Energy is on the process involving the continuing update and development of a Philippine Energy Plan (PEP) which has a 30-year time scope, which will help the country monitor and determine energy supply and demand vis-a-vis the growing demands of an industrializing country like the Philippines. Among the most vital component of the PEP is the thrust to pursue national programs for energy efficiency and demand-side management. Seven energy efficiency sub-programs have been identified for implementation, with a target savings of 623 million barrels of fuel oil equivalent (MMBFOE). A cumulative net savings of 237 billion pesos shall be generated against a total investment cost of 54.5 billion pesos. The Philippine energy sector will continue to develop and implement strategies to promote the efficient utilization of energy which will cover all aspects of the energy industry. The plan is focussed on the training and education of the various sectors on the aspects involved in the implementation of energy efficiency and demand-side management elements on a more aggressive note. The implementation of technical strategies by the department will continue on a higher and more extensive level, these are: energy utilization monitoring, consultancy and engineering services, energy efficiency testing and labelling program, and demand-side management programs for each sector. In summary, the PEP, as anchored in energy efficiency and demand-side management tools, among others, will ensure a continuous energy supply at affordable prices while incorporating environmental and social considerations. (author)

Demand side management scheme in smart grid with cloud computing approach using stochastic dynamic programming

Directory of Open Access Journals (Sweden)

S. Sofana Reka

2016-09-01

Full Text Available This paper proposes a cloud computing framework in smart grid environment by creating small integrated energy hub supporting real time computing for handling huge storage of data. A stochastic programming approach model is developed with cloud computing scheme for effective demand side management (DSM in smart grid. Simulation results are obtained using GUI interface and Gurobi optimizer in Matlab in order to reduce the electricity demand by creating energy networks in a smart hub approach.

The demand-side innovation policies in the context of small EU member country. Nõudluspoolsed innovatsioonipoliitikad Euroopa Liidu väikese liikmesriigi kontekstis

Directory of Open Access Journals (Sweden)

Tõnu Roolaht

2013-01-01

Full Text Available Demand-side innovation policies, in the form of regulations, public procurement, subsidies for private demand, and other measures, are often viewed as valuable additions to more traditional supply-side policies. The demand-side innovation policies should enable to facilitate the emergence of vital and sustainable links between innovation outputs and various markets. However, without sufficient institutional framework and policy experiences such measures could also contribute to new market distortions or crowding-out effects, which do not facilitate sustainable growth in innovations. The charting of possible risks of such policies should help to outline the criteria for aiming at sustainable effects. The purpose of this contribution is to offer suggestions about preconditions and policy characteristics, which should help to avoid the misuse of demand-side measures and facilitate the sustainability of desired changes in society. It is predominantly conceptual contribution but draws also extensively on case evidence about the effects of relevant policies and their discontinuation

Impact of Demand Side Response on a Commercial Retail Refrigeration System

Directory of Open Access Journals (Sweden)

Ibrahim M. Saleh

2018-02-01

Full Text Available The UK National Grid has placed increased emphasis on the development of Demand Side Response (DSR tariff mechanisms to manage load at peak times. Refrigeration systems, along with HVAC, are estimated to consume 14% of the UK’s electricity and could have a significant role for DSR application. However, characterized by relatively low individual electrical loads and massive asset numbers, multiple low power refrigerators need aggregation for inclusion in these tariffs. In this paper, the impact of the Demand Side Response (DSR control mechanisms on food retailing refrigeration systems is investigated. The experiments are conducted in a test-rig built to resemble a typical small supermarket store. The paper demonstrates how the temperature and pressure profiles of the system, the active power and the drawn current of the compressors are affected following a rapid shut down and subsequent return to normal operation as a response to a DSR event. Moreover, risks and challenges associated with primary and secondary Firm Frequency Response (FFR mechanisms, where the load is rapidly shed at high speed in response to changes in grid frequency, is considered. For instance, measurements are included that show a significant increase in peak inrush currents of approx. 30% when the system returns to normal operation at the end of a DSR event. Consideration of how high inrush currents after a DSR event can produce voltage fluctuations of the supply and we assess risks to the local power supply system.

Multi-objective demand side scheduling considering the operational safety of appliances

International Nuclear Information System (INIS)

Du, Y.F.; Jiang, L.; Li, Y.Z.; Counsell, J.; Smith, J.S.

2016-01-01

Highlights: • Operational safety of appliances is introduced in multi-objective scheduling. • Relationships between operational safety and other objectives are investigated. • Adopted Pareto approach is compared with Weigh and Constraint approaches. • Decision making of Pareto approach is proposed for final appliances’ scheduling. - Abstract: The safe operation of appliances is of great concern to users. The safety risk increases when the appliances are in operation during periods when users are not at home or when they are asleep. In this paper, multi-objective demand side scheduling is investigated with consideration to the appliances’ operational safety together with the electricity cost and the operational delay. The formulation of appliances’ operational safety is proposed based on users’ at-home status and awake status. Then the relationships between the operational safety and the other two objectives are investigated through the approach of finding the Pareto-optimal front. Moreover, this approach is compared with the Weigh and Constraint approaches. As the Pareto-optimal front consists of a set of optimal solutions, this paper proposes a method to make the final scheduling decision based on the relationships among the multiple objectives. Simulation results demonstrate that the operational safety is improved with the sacrifice of the electricity cost and the operational delay, and that the approach of finding the Pareto-optimal front is effective in presenting comprehensive optimal solutions of the multi-objective demand side scheduling.

Supply shortage forecast in Ontario: The significance of demand-side management (DSM); its tools and techniques

International Nuclear Information System (INIS)

Saini, S.

2004-01-01

Aspects of the recent report by the Ontario Electricity Conservation and Supply Task Force and Independent Market Operator which forecasts acute power supply shortages in Ontario, are discussed. Immediate action is recommended to avert the problem. The principal recommendation concerns the adoption of Demand Side Management as a tool to reduce the widening gap between supply and demand, citing supply shortage, imports, high prices, deregulated market and environmental concerns as the driving forces which push for the adoption of DSM. It is claimed that DSM, through its tools such as Demand/Load Response Programs and Time-of-Use rates has the capacity to create the necessary balance between supply and demand more efficiently, and in a more timely fashion than supply side management. The demand for adoption of DSM is justified on the basis of a careful examination of the magnitude and significance of each of the driving forces affecting the electricity supply in Ontario, as well as the benefits and techniques of DSM designed to manage power shortages. Energy Conservation and Efficiency and Demand/Load Response Programs are discussed as the principal DSM techniques, while Dynamic/Real Time Pricing, Time-of-Use Rates, Automated /Smart Metering, Web-based/Communication Systems, Reliability-based Programs, Market/Price-based programs, and Types of Load Control are described as the principal tools used by DSM. DSM program approaches and strategies are also reviewed, along with a brief list of successful examples of DSM applications. 3 figs

Supply shortage forecast in Ontario: The significance of demand-side management (DSM); its tools and techniques

Energy Technology Data Exchange (ETDEWEB)

Saini, S.

2004-06-01

Aspects of the recent report by the Ontario Electricity Conservation and Supply Task Force and Independent Market Operator which forecasts acute power supply shortages in Ontario, are discussed. Immediate action is recommended to avert the problem. The principal recommendation concerns the adoption of Demand Side Management as a tool to reduce the widening gap between supply and demand, citing supply shortage, imports, high prices, deregulated market and environmental concerns as the driving forces which push for the adoption of DSM. It is claimed that DSM, through its tools such as Demand/Load Response Programs and Time-of-Use rates has the capacity to create the necessary balance between supply and demand more efficiently, and in a more timely fashion than supply side management. The demand for adoption of DSM is justified on the basis of a careful examination of the magnitude and significance of each of the driving forces affecting the electricity supply in Ontario, as well as the benefits and techniques of DSM designed to manage power shortages. Energy Conservation and Efficiency and Demand/Load Response Programs are discussed as the principal DSM techniques, while Dynamic/Real Time Pricing, Time-of-Use Rates, Automated /Smart Metering, Web-based/Communication Systems, Reliability-based Programs, Market/Price-based programs, and Types of Load Control are described as the principal tools used by DSM. DSM program approaches and strategies are also reviewed, along with a brief list of successful examples of DSM applications. 3 figs.

A Novel Prosumer-Based Energy Sharing and Management (PESM) Approach for Cooperative Demand Side Management (DSM) in Smart Grid

OpenAIRE

Sohail Razzaq; Rehman Zafar; Naveed Ahmed Khan; Asif Raza Butt; Anzar Mahmood

2016-01-01

Increasing population and modern lifestyle have raised energy demands globally. Demand Side Management (DSM) is one important tool used to manage energy demands. It employs an advanced power infrastructure along with bi-directional information flow among utilities and users in order to achieve a balanced load curve and minimize demand-supply mismatch. Traditionally, this involves shifting the electricity demand from peak hours to other times of the day in an optimized manner. Multiple users e...

Impact on energy requirements and emissions of heat pumps and micro-cogenerators participating in demand side management

International Nuclear Information System (INIS)

Cooper, Samuel J.G.; Hammond, Geoffrey P.; McManus, Marcelle C.; Rogers, John G.

2014-01-01

The potential impacts of participating in demand side management (DSM) on the performance of air source heat pumps (ASHP) and micro-combined heat and power (mCHP) units are considered by this study. As significant consumers and generators of electricity at the distribution level, large numbers of heat pumps and micro-cogenerators would provide considerable scope for participation in DSM systems. However, it is possible that operating regimes which are optimised for grid considerations will not achieve the maximum performance that is possible from the units. Modelling has been conducted to investigate the significance of this effect, considering the case where local distribution constraints are the main driver for demand side interventions. A model of domestic electrical demand has been adapted to consider a neighbourhood of 128 dwellings in order to identify when interventions are necessary. This has been combined with dynamic models of two combustion engine micro-cogenerators, a solid oxide fuel cell micro-cogenerator and two ASHPs. A simple thermal model of each building is combined with a range of user preferences in order to determine the preferred operating profiles of the heating units. The DSM scheme analysed here is likely to have minimal impact on the emissions and energy requirements associated with each heating unit. Its effect is similar to that which occurs without DSM if the control system gain is relaxed such that equivalent thermal comfort is achieved. DSM can reduce the peak electrical demand of the neighbourhood. However, in the scenarios investigated, it is unlikely that the peaks can be reduced sufficiently such that they do not exceed the capacity of the local distribution transformer if ASHPs are used in all dwellings. By using a combination of mCHP units with ASHPs, it is possible to supply heating to all dwellings without exceeding this capacity. In this case, the use of DSM can increase the ratio of ASHPs used. In the context of a low

Increasing access to institutional deliveries using demand and supply side incentives: early results from a quasi-experimental study

Directory of Open Access Journals (Sweden)

Serwadda David

2011-03-01

Full Text Available Abstract Background Geographical inaccessibility, lack of transport, and financial burdens are some of the demand side constraints to maternal health services in Uganda, while supply side problems include poor quality services related to unmotivated health workers and inadequate supplies. Most public health interventions in Uganda have addressed only selected supply side issues, and universities have focused their efforts on providing maternal services at tertiary hospitals. To demonstrate how reforms at Makerere University College of Health Sciences (MakCHS can lead to making systemic changes that can improve maternal health services, a demand and supply side strategy was developed by working with local communities and national stakeholders. Methods This quasi-experimental trial is conducted in two districts in Eastern Uganda. The supply side component includes health worker refresher training and additions of minimal drugs and supplies, whereas the demand side component involves vouchers given to pregnant women for motorcycle transport and the payment to service providers for antenatal, delivery, and postnatal care. The trial is ongoing, but early analysis from routine health information systems on the number of services used is presented. Results Motorcyclists in the community organized themselves to accept vouchers in exchange for transport for antenatal care, deliveries and postnatal care, and have become actively involved in ensuring that women obtain care. Increases in antenatal, delivery, and postnatal care were demonstrated, with the number of safe deliveries in the intervention area immediately jumping from Conclusions Transport and service vouchers appear to be a viable strategy for rapidly increasing maternal care. MakCHS can design strategies together with stakeholders using a learning-by-doing approach to take advantage of community resources.

Residual strains and microstructure development in single and sequential double sided friction stir welds in RQT-701 steel

Energy Technology Data Exchange (ETDEWEB)

Barnes, S.J. [School of Materials, University of Manchester, Grosvenor Street, Manchester M1 7HS (United Kingdom)], E-mail: simon.barnes-2@manchester.ac.uk; Steuwer, A. [FaME38, ILL ESRF, 6 rue J.Horowitz, 38042 Grenoble, Cedex (France); University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Mahawish, S. [School of Materials, University of Manchester, Grosvenor Street, Manchester M1 7HS (United Kingdom); Johnson, R. [TWI Yorkshire, Wallis Way, Catcliffe, Rotherham S60 5TZ (United Kingdom); Withers, P.J. [School of Materials, University of Manchester, Grosvenor Street, Manchester M1 7HS (United Kingdom)

2008-09-25

Single and double sided partial penetration friction stir butt welds, in a rolled, quenched and tempered steel (RQT-701), were produced at The Welding Institute (TWI) under controlled process conditions. The residual strain distributions in the longitudinal and transverse directions have been measured using energy dispersive synchrotron X-ray diffraction. The measured strains were indicative of longitudinal tensile residual stresses at levels greater than the 0.2% yield stress of the parent metal in both the single and double pass welds. In both cases, the maximum tensile strain was found in the parent metal at the boundary of the heat affected zone (HAZ). Microstructural analysis of the welds was carried out using optical microscopy and hardness variations were also mapped across the weld-plate cross-section. The maximum hardness was observed in the mixed bainite/martensite structure of the weld nugget on the advancing side of the stir zone. The minimum hardness was observed in the HAZ.

Residual strains and microstructure development in single and sequential double sided friction stir welds in RQT-701 steel

International Nuclear Information System (INIS)

Barnes, S.J.; Steuwer, A.; Mahawish, S.; Johnson, R.; Withers, P.J.

2008-01-01

Single and double sided partial penetration friction stir butt welds, in a rolled, quenched and tempered steel (RQT-701), were produced at The Welding Institute (TWI) under controlled process conditions. The residual strain distributions in the longitudinal and transverse directions have been measured using energy dispersive synchrotron X-ray diffraction. The measured strains were indicative of longitudinal tensile residual stresses at levels greater than the 0.2% yield stress of the parent metal in both the single and double pass welds. In both cases, the maximum tensile strain was found in the parent metal at the boundary of the heat affected zone (HAZ). Microstructural analysis of the welds was carried out using optical microscopy and hardness variations were also mapped across the weld-plate cross-section. The maximum hardness was observed in the mixed bainite/martensite structure of the weld nugget on the advancing side of the stir zone. The minimum hardness was observed in the HAZ

Impact of energy storage in buildings on electricity demand side management

International Nuclear Information System (INIS)

Qureshi, Waqar A.; Nair, Nirmal-Kumar C.; Farid, Mohammad M.

2011-01-01

Research highlights: → Phase change material (PCM) application for space heating has been implemented and assessed for built environment. → Real-Time Pricing (RTP) is assessed as tool to implement Demand Side Management programs effectively. → Two buildings, with and without PCM, have been compared for space heating using RTP in functional electricity market. → PCM found to offer peak load shifting, energy conservation, and reduction in price of electricity. -- Abstract: This paper assesses impact of using phase change materials (PCM) in buildings to leverage its thermal energy storage capability. The emphasis is from an electricity demand side perspective with case studies that incorporates wholesale electricity market data of New Zealand. The results presented in this paper show that for space heating application significant advantages could be obtained using PCM built structures. These positive impacts include peak load shifting, energy conservation and reduction in peak demand for network line companies and potential reduction in electricity consumption and savings for residential customers. This paper uses a testing facility that consists of two identically designed and shaped offices built at Tamaki Campus location of the University of Auckland, New Zealand. The walls and ceilings of one office are finished with ordinary gypsum boards while the interior of the other office is finished with PCM impregnated gypsum boards. Controlled heating facility is provided in both the offices for maintaining temperature within the range of human comfort. This facility is equipped with advanced data acquisition equipment for data monitoring and archiving both locally within the offices and also remotely. Through actual observations and analysis this paper demonstrates two major impacts of DSM. First, the application of phase change material (PCM) in building environment enabling efficient thermal storage to achieve some reduction in the overall electrical energy

A Smart Grid Framework for Optimally Integrating Supply-Side, Demand-Side and Transmission Line Management Systems

Directory of Open Access Journals (Sweden)

Chukwuka Monyei

2018-04-01

Full Text Available A coordinated centralized energy management system (ConCEMS is presented in this paper that seeks to integrate for optimal grid operation—the supply side energy management system (SSEMS, home energy management system (HEMS and transmission line management system (TLMS. ConCEMS in ensuring the optimal operation of an IEEE 30-bus electricity network harmonizes the individual objective function of SSEMS, HEMS and TLMS to evolve an optimal dispatch of participating demand response (DR loads that does not violate transmission line ampacity limits (TLMS constraint while minimizing consumer cost (HEMS constraint and supply side operations cost (SSEMS constraint. An externally constrained genetic algorithm (ExC-GA that is influenced by feedback from TLMS is also presented that intelligently varies the dispatch time of participating DR loads to meet the individual objective functions. Hypothetical day ahead dynamic pricing schemes (Price1, Price2 and Price3 have also been adopted alongside an existing time of use (Price0 pricing scheme for comparison and discussion while a dynamic thermal line rating (DTLR algorithm has also been incorporated to dynamically compute power limits based on real time associated data.

DEMONSTRATION OF THE ENVIRONMENTAL AND DEMAND-SIDE MANAGEMENT BENEFITS OF GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEMS

Science.gov (United States)

This study investigated the pollutant emission reduction and demand-side management potential of 16 photovoltaic (PV) systems installed across the U.S. in 1993 and 1994. The project was sponsored by the U.S. Environmental Protection Agency (EPA) and 11 electric utilities. This ar...

An Economic Evalution of Demand-side Energy Storage Systems by using a Multi-agent based Electricity Market

Science.gov (United States)

Furusawa, Ken; Sugihara, Hideharu; Tsuji, Kiichiro

Opened wholesale electric power market in April 2005, deregulation of electric power industry in Japan has faced a new competitive environment. In the new environment, Independent Power Producer (: IPP), Power Producer and Supplier (: PPS), Load Service Entity (: LSE) and electric utility can trade electric energy through both bilateral contracts and single-price auction at the electricity market. In general, the market clearing price (: MCP) is largely changed by amount of total load demand in the market. The influence may cause price spike, and consequently the volatility of MCP will make LSEs and their customers to face a risk of revenue and cost. DSM is attracted as a means of load leveling, and has effect on decreasing MCP at peak load period. Introducing Energy Storage systems (: ES) is one of DSM in order to change demand profile at customer-side. In case that customers decrease their own demand at jumped MCP, a bidding strategy of generating companies may be changed their strategy. As a result, MCP is changed through such complex mechanism. In this paper the authors evaluate MCP by multi-agent. It is considered that customer-side ES has an effect on MCP fluctuation. Through numerical examples, this paper evaluates the influence on MCP by controlling customer-side ES corresponding to variation of MCP.

Student figures in friction

DEFF Research Database (Denmark)

Nielsen, Gritt B.

, students' room for participation in their own learning, influenced by demands for efficiency, flexibility and student-centred education. The thesis recasts the anthropological endeavour as one of ‘figuration work'. That is, ‘frictional events' are explored as moments when conflicting figures...

Macroeconomics with Financial Frictions: A Survey

OpenAIRE

Markus K. Brunnermeier; Thomas M. Eisenbach; Yuliy Sannikov

2012-01-01

This article surveys the macroeconomic implications of financial frictions. Financial frictions lead to persistence and when combined with illiquidity to non-linear amplification effects. Risk is endogenous and liquidity spirals cause financial instability. Increasing margins further restrict leverage and exacerbate downturns. A demand for liquid assets and a role for money emerges. The market outcome is generically not even constrained efficient and the issuance of government debt can lead t...

Adaptive heat pump and battery storage demand side energy management

Science.gov (United States)

Sobieczky, Florian; Lettner, Christian; Natschläger, Thomas; Traxler, Patrick

2017-11-01

An adaptive linear model predictive control strategy is introduced for the problem of demand side energy management, involving a photovoltaic device, a battery, and a heat pump. Moreover, the heating influence of solar radiation via the glass house effect is considered. Global sunlight radiation intensity and the outside temperature are updated by weather forecast data. The identification is carried out after adapting to a time frame witch sufficiently homogeneous weather. In this way, in spite of the linearity an increase in precision and cost reduction of up to 46% is achieved. It is validated for an open and closed loop version of the MPC problem using real data of the ambient temperature and the global radiation.

Properties of Friction Welding of Dissimilar Metals WCu-Cu Weld for Electrical Contact Device

Energy Technology Data Exchange (ETDEWEB)

An, Y. H.; Yoon, G. G. [Korea Electrotechnology Research Institute (Korea); Min, T. K. [Chungnam National University (Korea); Han, B. S. [Chonbuk National University (Korea)

2000-04-01

A copper-tungsten sintered alloy(WCu) has been friction-welded to a tough pitch copper (Cu) in order to investigate friction weldability. The maximum tensile strength of the WCu-Cu friction welded joints had up to 96% of those of the Cu base metal under the condition of friction time 0.6sec, friction pressure 45MPa, upset pressure 125MPa and upset time 5.0sec. And it is confirmed that the tensile strength of friction welded joints are influenced highly by upset pressure rather than friction time. And it is considered that mixed layer was formed in the Cu adjacent side to the weld interface, W particles included in mixed layer induced fracture in the Cu adjacent side to the weld interface and also, thickness of mixed layer was reduced as upset pressure increase. (author). refs., figs., tabs.

Friction welding method

International Nuclear Information System (INIS)

Ishida, Ryuichi; Hatanaka, Tatsuo.

1969-01-01

A friction welding method for forming a lattice-shaped base and tie plate supporter for fuel elements is disclosed in which a plate formed with a concavity along its edge is pressure welded to a rotating member such as a boss by longitudinally contacting the projecting surfaces remaining on either side of the concavity with the rotating member during the high speed rotation thereof in the presence of an inert gas. Since only the two projecting surfaces of the plate are fused by friction to the rotary member, heat expansion is absorbed by the concavity to prevent distortion; moreover, a two point contact surface assures a stable fitting and promotes the construction of a rigid lattice in which a number of the abovementioned plates are friction welded between rotating members to form any desired complex arrangement. The inert has serves to protect the material quality of the contacting surfaces from air during the welding step. The present invention thus provides a method in which even Zircaloy may be friction welded in place of casting stainless steel in the construction of supporting lattices to thereby enhance neutron economy. (K. J. Owens)

Principles concerning the progress of the gas demand side management in Romania

International Nuclear Information System (INIS)

Leca, A.; Statie, E.; Nistoran, D.

1996-01-01

The consequences of the application of demand side management (DSM) and integrated resources planning (IRP) notions for natural gas are analysed. Present socio-economic context in Romania - from a geopolitical point of view - obviously highlights a set of difficult gas supply problems in our country related to: the impossibility of satisfying the consumption demand from internal resources; the necessity of ensuring by imports of an important quantity of gas, which entails an important foreign currency expenditure and possible political pressures which an unique supplier could exert; the requirement of alignment to the western European country legislation, at an institutional and economical practice level. Each of these problems related to the gas-based power production and all together impose the tackling of DSM and IRP requirements from a strategic point of view. Some conclusions and proposals are presented. (author) 1 fig., 4 refs

Demand-Side Management and European environmental and energy goals. An optimal complementary approach

International Nuclear Information System (INIS)

Bergaentzle, Claire; Clastres, Cedric; Khalfallah, Haikel

2013-12-01

Demand side management (DSM) in electricity markets could improve energy efficiency and achieve environmental targets through controlled consumption. For the past 10 years or so DSM programs have registered significant results. However, detailed analysis of its real impact as observed by a large number of pilot studies suggests that such programs need to be fine-tuned to suit clearly identified conditions. This study aims to provide recommendations for the instruments to be used to prompt demand response with a view to maximizing energy and environmental efficiencies of various countries. The present study suggests that different DSM models should be deployed depending on the specific generation mix in any given country. Beside the natural benefits from cross-borders infrastructures, DSM improves the flexibility and reliability of the energy system, absorbing some shock on generation mix. We show efficiency increases with demand response but at a decreasing rate. So, according to rebound and report effects, simple DSM tools could be preferred. (authors)

The Wisconsin experience with incentives for demand-side management

International Nuclear Information System (INIS)

Landgren, D.A.

1990-01-01

It has been noted that, within traditional regulatory frameworks for electric utilities, factors exist which discourage demand side management (DSM) and that there is a lack of positive incentives for DSM. Regulatory agencies should therefore make it possible for DSM measures to benefit from the same treatment as supply-side measures. The Wisconsin Public Service Commission (WPSC) has recognized this need and has adopted various measures accordingly. The need for efficiency incentives is described according to the particular experience of Wisconsin Electric concerning their recourse to a DSM incentive and according to new incentive models being tested in collaboration with other electricity suppliers in Wisconsin. The WPSC has concluded that the fact of considering the costs relating to DSM as expenses or capitalizing them within the rate base does not motivate the utility to promote DSM programs. The WPSC has thus decided to experiment with energy efficiency incentives in order to evaluate their eventual impact. The choice of the type of incentive had an objective of starting the process in an area where the lack of experience has created, from the regulatory point of view, a reticence on the part of utilities to engage in DSM programs. The WPSC has designed a variety of incentive models which have been adapted to each utility's own situation. Specific incentive programs developed for three Wisconsin utilities are reviewed

Ensuring the security of electricity supply in Ontario: is demand-side management the answer?

International Nuclear Information System (INIS)

Chuddy, B.

2004-01-01

This paper examines the issues relating to ensuring the security of electricity supply in Ontario. In particular, it focuses on demand-side management as a means of achieving these objectives. The solution involves both conservation and supply. It is therefore critical that there be investment in new supply with multiple buyers/sellers. regulatory environment and pricing could encourage conservation

Optimal Load Response to Time-of-Use Power Price for Demand Side Management in Denmark

DEFF Research Database (Denmark)

Hu, Weihao; Chen, Zhe; Bak-Jensen, Birgitte

2010-01-01

-of-use power price for demand side management in order to save the energy costs as much as possible. 3 typical different kinds of loads (industrial load, residential load and commercial load) in Denmark are chosen as study cases. The energy costs decrease up to 9.6% with optimal load response to time......-of-use power price for different loads. Simulation results show that the optimal load response to time-of-use power price for demand side management generates different load profiles and reduces the load peaks. This kind of load patterns may also have significant effects on the power system normal operation.......Since the hourly spot market price is available one day ahead in Denmark, the price could be transferred to the consumers and they may shift their loads from high price periods to the low price periods in order to save their energy costs. This paper presents a load optimization method to time...

Increasing access to institutional deliveries using demand and supply side incentives: early results from a quasi-experimental study.

Science.gov (United States)

Ekirapa-Kiracho, Elizabeth; Waiswa, Peter; Rahman, M Hafizur; Makumbi, Fred; Kiwanuka, Noah; Okui, Olico; Rutebemberwa, Elizeus; Bua, John; Mutebi, Aloysius; Nalwadda, Gorette; Serwadda, David; Pariyo, George W; Peters, David H

2011-03-09

Geographical inaccessibility, lack of transport, and financial burdens are some of the demand side constraints to maternal health services in Uganda, while supply side problems include poor quality services related to unmotivated health workers and inadequate supplies. Most public health interventions in Uganda have addressed only selected supply side issues, and universities have focused their efforts on providing maternal services at tertiary hospitals. To demonstrate how reforms at Makerere University College of Health Sciences (MakCHS) can lead to making systemic changes that can improve maternal health services, a demand and supply side strategy was developed by working with local communities and national stakeholders. This quasi-experimental trial is conducted in two districts in Eastern Uganda. The supply side component includes health worker refresher training and additions of minimal drugs and supplies, whereas the demand side component involves vouchers given to pregnant women for motorcycle transport and the payment to service providers for antenatal, delivery, and postnatal care. The trial is ongoing, but early analysis from routine health information systems on the number of services used is presented. Motorcyclists in the community organized themselves to accept vouchers in exchange for transport for antenatal care, deliveries and postnatal care, and have become actively involved in ensuring that women obtain care. Increases in antenatal, delivery, and postnatal care were demonstrated, with the number of safe deliveries in the intervention area immediately jumping from Voucher revenues have been used to obtain needed supplies to improve quality and to pay health workers, ensuring their availability at a time when workloads are increasing. Transport and service vouchers appear to be a viable strategy for rapidly increasing maternal care. MakCHS can design strategies together with stakeholders using a learning-by-doing approach to take advantage of

Barriers and Opportunities to Broader Adoption of Integrated Demand Side Management at Electric Utilities: A Scoping Study

Energy Technology Data Exchange (ETDEWEB)

Potter, Jennifer [Hawaii Natural Energy Institute, Honolulu, HI (United States); Stuart, Elizabeth [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Div.; Cappers, P [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Div.

2018-02-13

Integrated demand-side management (IDSM) is a strategic approach to designing and delivering a portfolio of demand side management (DSM) programs to customers. IDSM typically delivers customer centric strategies with the goal of increasing the amount of DSM in the field, but doing so in a way that integrates various measures and technologies to improve their collective performance and/or penetration. Specifically, IDSM can be defined as the integrated or coordinated delivery of three or more of: (1) energy efficiency (EE), (2) demand response (DR), (3) distributed generation (DG), (4) storage, (5) electric vehicle (EV) technologies, and (6) time-based rate programs to residential and commercial electric utility customers. The electric industry’s limited experience deploying IDSM to date suggests that significant barriers may exist. A Berkeley Lab report “Barriers and Opportunities to Broader Adoption of Integrated Demand Side Management at Electric Utilities: A Scoping Study” explores recent electric utility experience with IDSM to provide an assessment of the barriers and potential benefits perceived or experienced by program administrators in their attempts to implement integrated programs. The research draws on surveys and interviews with eleven staff from a sample of eight DSM program administrators and program implementers who were currently implementing or had previously attempted to implement an IDSM program or initiative. Respondents provided their perspectives on drivers for IDSM and barriers to broader deployment. They also reported on actions they had undertaken to promote expanded delivery of IDSM and provided their assessments of the most important under-tapped opportunities for expanding IDSM efforts, both for program administrator and regulatory organizations.

A Survey on Friction Stir Welding Of Dissimilar Magnesium Alloys

Science.gov (United States)

Unnikrishnan, M. A.; Raja, Dhas. J. Edwin

2017-10-01

There is a consistent demand for superior materials in every industry. The areas on demand are automobile and aerospace sectors in major.. The most commonly used material in these fields is Aluminium.Though it possess all the properties up to some extent constant demand is pushing for alternate materials. Dissimilar alloys have been a relatively new approach towards these fields.. Friction stir welding dissimilar alloys is a big leap in Automobile sector. In this paper a detailed review of Friction stir welding of Dissimilar Magnesium alloys has been done. This work will serve as a reference to subsequent researchers.

How to optimize tourism destination supply: A case in Shanghai from perspective of supplier and demand side perception

Science.gov (United States)

Xue, Huaju; Fang, Chengjiang

2018-02-01

It is vital to assess the regional tourist supply capability by suppliers and demand groups. The supply side’s evaluation of the regional supply capacity determines the direction of the supply investment in future, the demand side’s evaluation indicates their satisfaction degree of the destination supply and also effects their revisit the tourism destination. Therefore, the assessment of the supply and demand sides is an important reference for the reform of destination supply side, which helps us find the shortage of the destination supply factors and optimize tourism destination supply promptly. This paper through investigating tourism supply and demand groups in Shanghai, used the survey data and constructed tourism supply optimization model, analyzed the current situation of tourism supply factors in Shanghai. Results showed that the environment of Shanghai should be improved first, including improving urban air and water quality, up-grading public sanitation and increasing urban green coverage. Other supply factors improved priority were information and marketing, we should improve the information consultation of scenic spots, increase the intensity of tourism promotion and provide more free travel publicity brochures.

Dry friction of microstructured polymer surfaces inspired by snake skin

OpenAIRE

Martina J. Baum; Lars Heepe; Elena Fadeeva; Stanislav N. Gorb

2014-01-01

Summary The microstructure investigated in this study was inspired by the anisotropic microornamentation of scales from the ventral body side of the California King Snake (Lampropeltis getula californiae). Frictional properties of snake-inspired microstructured polymer surface (SIMPS) made of epoxy resin were characterised in contact with a smooth glass ball by a microtribometer in two perpendicular directions. The SIMPS exhibited a considerable frictional anisotropy: Frictional coefficients ...

DSM [demand-side management] financing: Risks and incentives

International Nuclear Information System (INIS)

Dayton, D.S.

1992-01-01

Opportunities to make investments in demand side management (DSM) are widespread, especially among large, complex, energy-intensive customers. Acceptable economics are found for energy efficiency improvements, new construction or renovation, replacement of failing or obsolete equipment, and retrofit of existing facilities with more efficient equipment and operations. Market imperfections and technical limitations intrude on the DSM investment process. These intrusions are examined from a financial viewpoint by considering the return on investment and risks faced by the three potential investors in DSM opportunities: the customer, the utility, and the third party contractor or financier. These risks are illustrated by examining the cash flow of a typical project depicting a comprehensive energy efficiency installation in a medium to large industrial or institutional facility. The spread between the customer's risk/return ratio and that of the other two investors is shown to be surprisingly large. A utility role in marketing and financing, as opposed to direct subsidizing of customers or direct purchase of DSM resources from third parties, is explored as an efficient response to these realities. 2 figs., 3 tabs

A Midwest utility's perspective of DSM [demand-side management]: Balancing the needs of customers, shareholders and the environment

International Nuclear Information System (INIS)

Collins, G.F.

1990-01-01

PSI Energy, a predominately coal-burning Indiana electric utility, is very concerned about the environment and is using demand-side management (DSM) as part of a strategy to balance the sometimes conflicting interests of the environment, the economy, customers and shareholders. Faced with slow growth within its service territory, an abundance of low-cost, high sulfur coal burning baseload capacity, massive future expenditures for acid rain mitigation and a weakened financial state due to a cancelled nuclear project, PSI Energy has taken a novel approach to preserving value for customers, shareholders, the economy and environment. To accomodate Indiana's goal of least cost utility planning, PSI initiated an all-source bidding program in which it solicited bids for peaking capacity or the equivalent. Four parallel but separate solicitations were pursued: combustion turbine manufacturers for PSI owned and operated capacity, other utilities and non-utility generators for purchased power and third parties for demand-side management. PSI's philosophy with respect to bidding can be expressed as: simplicity, flexibility, creativity, partnerships, expeditious and fairness. There is a minimum bid of 5 MW of summer peak demand reduction, and the minimum contract length is 10 years. The entire 550 MW capacity block available to be filled in the program is open to demand-side resources. The ten major evaluation criteria involved in the program are: price, sponsor qualifications, operational impact, marketing plan, technology, financing plan, verification and measurement, form of security, project management plan, and project cost estimates

Frictions in Project-Based Supply of Permits

International Nuclear Information System (INIS)

Liski, M.; Virrankoski, J.

2004-01-01

Emissions trading in climate change can entail large overall cost savings and transfers between developed and developing countries. However, the search for acceptable JI or CDM projects implies a deviation from the perfect market framework used in previous estimations. Our model combines the search market for projects with a frictionless permit market to quantify the supply-side frictions in the CO2 market. We also decompose the effects of frictions into the effects of search friction, bargaining, and bilateralism. A calibration using previous cost estimates of CO2 reductions illustrate changes in cost savings and allocative implications

Internal friction in irradiated textolite

International Nuclear Information System (INIS)

Zajkin, Yu.A.; Kozhamkulov, B.A.; Koztaeva, U.P.

1996-01-01

Structural relaxation in irradiated textolite of ST and ST-EhTF trade marks presenting pressed material got by method of impregnation of fibreglass by phenole and epoxytriphenole binders relatively. Measuring of temperature dependences of internal friction (TDIF) is carried out in torsional pendulum at oscillation frequency 0.6-1.0 Hz before and after irradiation by stopped gamma-quanta with energy 3 MeV on electron accelerator EhLU-4. α and β peaks, related with segments motion in base and side chains of macromolecular have being observed on TDIF of all textolite. Growth of peaks height after irradiation evident about increase of segments mobility in base chain and about de-freezing of segments in side chains and it could be considered as qualitative measure of radiation destruction rate. Comparison of temperature dependences of internal friction indicates on higher radiation stability of textolite of ST-EhTF trade mark

Effect of friction time on mechanical and metallurgical properties of continuous drive friction welded Ti6Al4V/SUS321 joints

International Nuclear Information System (INIS)

Li, Peng; Li, Jinglong; Salman, Muhammad; Liang, Li; Xiong, Jiangtao; Zhang, Fusheng

2014-01-01

Highlights: • The effect of friction time on the microstructure and joint strength was studied. • The fit of burn-off lengths at different times yields a simple equation. • The longer friction time leads to oversized flash in Ti6Al4V side and overgrown IMCs. • An IMZ with width less than 3 μm is beneficial to make a strong metallurgical bond. • The average strength of 560 MPa is obtained and higher than ever reported results. - Abstract: Dissimilar joint of Ti6Al4V titanium alloy and SUS321 stainless steel was fabricated by continuous drive friction welding. The effect of friction time on the mechanical properties was evaluated by hardness measurement and tensile test, while the interfacial microstructure and fracture morphologies were analyzed by scanning electron microscope, energy dispersive spectroscope and X-ray Diffraction. The results show that the tensile strength increases with friction time under the experimental conditions. And the maximum average strength 560 MPa, which is 90.3% of the SUS321 base metal, is achieved at a friction time of 4 s. For all samples, studied fracture occurred along the joint interface, where intermetallic compounds like FeTi, Fe 2 Ti, Ni 3 (Al, Ti) and Fe 3 Ti 3 O and many other phases were formed among elements from the two base metals. The width of intermetallic compounds zone increases with friction time up to 3 μm, below which it is beneficial to make a strong metallurgical bond. However, the longer friction time leads to oversized flash on the Ti6Al4V side and overgrown intermetallic compounds. Finally the optimized friction time was discussed to be in the range of 2–4 s, under which the sound joint with good reproducibility can be expected

Evaluation of flexible demand-side load-following reserves in power systems with high wind generation penetration

NARCIS (Netherlands)

Paterakis, N.G.; Catalao, J.P.S.; Ntomaris, A.V.; Erdinc, O.

2015-01-01

In this study, a two-stage stochastic programming joint energy and reserve day-ahead market structure is proposed in order to procure the required load-following reserves to tackle with wind power production uncertainty. Reserves can be procured both from generation and demand-side. Responsive

Optimization Models and Methods for Demand-Side Management of Residential Users: A Survey

Directory of Open Access Journals (Sweden)

Antimo Barbato

2014-09-01

Full Text Available The residential sector is currently one of the major contributors to the global energy balance. However, the energy demand of residential users has been so far largely uncontrollable and inelastic with respect to the power grid conditions. With the massive introduction of renewable energy sources and the large variations in energy flows, also the residential sector is required to provide some flexibility in energy use so as to contribute to the stability and efficiency of the electric system. To address this issue, demand management mechanisms can be used to optimally manage the energy resources of customers and their energy demand profiles. A very promising technique is represented by demand-side management (DSM, which consists in a proactive method aimed at making users energy-efficient in the long term. In this paper, we survey the most relevant studies on optimization methods for DSM of residential consumers. Specifically, we review the related literature according to three axes defining contrasting characteristics of the schemes proposed: DSM for individual users versus DSM for cooperative consumers, deterministic DSM versus stochastic DSM and day-ahead DSM versus real-time DSM. Based on this classification, we provide a big picture of the key features of different approaches and techniques and discuss future research directions.

Sustainability of Welding Process through Bobbin Friction Stir Welding

Science.gov (United States)

Sued, M. K.; Samsuri, S. S. M.; Kassim, M. K. A. M.; Nasir, S. N. N. M.

2018-03-01

Welding process is in high demand, which required a competitive technology to be adopted. This is important for sustaining the needs of the joining industries without ignoring the impact of the process to the environment. Friction stir welding (FSW) is stated to be benefitting the environment through low energy consumption, which cannot be achieved through traditional arc welding. However, this is not well documented, especially for bobbin friction stir welding (BFSW). Therefore, an investigation is conducted by measuring current consumption of the machine during the BFSW process. From the measurement, different phases of BFSW welding process and its electrical demand are presented. It is found that in general total energy in BFSW is about 130kW inclusive of all identified process phases. The phase that utilise for joint formation is in weld phase that used the highest total energy of 120kWs. The recorded total energy is still far below the traditional welding technology and the conventional friction stir welding (CFSW) energy demand. This indicates that BFSW technology with its vast benefit able to sustain the joining technology in near future.

Economic profitability analysis of demand side management program

International Nuclear Information System (INIS)

Sheen, J.N.

2005-01-01

This study considers both the internal and external costs of the utility in deriving the avoided capacity cost (ACC) and avoided operating cost (AOC) induced in an electric utility caused by the implementation of a demand side management program (DSM). In calculating the ACC, a multiple objective linear programming model is developed. Meanwhile, the AOC is calculated by considering the differences between the total and specific time period energy consumption ratios before and after the implementation of the DSM program. This study also develops an economic analysis method using Net Present Value and Pay Back Year models to assess the economic profitability of implementing a DSM program from a participant's point of view. The design and construction of a partial load leveling eutectic salt Cooling Energy Storage (CES) air conditioning system in a target office building in Kaohsiung, Taiwan, is discussed in order to simulate the cost benefit of the CES system from the perspective of the utility and from that of the participant. The results confirm the effectiveness of the developed models in simulating the economic benefits of implementing a DSM program from the perspectives of both the utility and the participant

Cost benefit analysis of the demand side management programs; Analise de custos e beneficios economicos de programas de gerencia pelo lado da demanda

Energy Technology Data Exchange (ETDEWEB)

Schechtman, R; Baum, M [PROMON Engenharia SA, Rio de Janeiro, RJ (Brazil)

1990-12-31

The several cost and benefit components of the demand side management programs for the society groups, including the concessionaire, consumers and society as a whole are studied. The rule evaluations of management programs by demand side, used by North American concessionaire are also discussed. Finally, the numerical examples, that consolidating the concepts and rules evaluation are presented. (C.G.C.). 5 refs, 1 fig, 3 tabs.

Bulk electric system reliability evaluation incorporating wind power and demand side management

Science.gov (United States)

Huang, Dange

correlations and the interactive effects of wind power and load forecast uncertainty on system reliability are examined. The concept of the security cost associated with operating in the marginal state in the well-being framework is incorporated in the economic analyses associated with system expansion planning including wind power and load forecast uncertainty. Overall reliability cost/worth analyses including security cost concepts are applied to select an optimal wind power injection strategy in a bulk electric system. The effects of the various demand side management measures on system reliability are illustrated using the system, load point, and well-being indices, and the reliability index probability distributions. The reliability effects of demand side management procedures in a bulk electric system including wind power and load forecast uncertainty considerations are also investigated. The system reliability effects due to specific demand side management programs are quantified and examined in terms of their reliability benefits.

Optimization of wheel-rail interface friction using top-of-rail friction modifiers: State of the art

Science.gov (United States)

Khan, M. Roshan; Dasaka, Satyanarayana Murty

2018-05-01

High Speed Railways and Dedicated Freight Corridors are the need of the day for fast and efficient transportation of the ever growing population and freight across long distances of travel. With the increase in speeds and axle loads carried by these trains, wearing out of rails and train wheel sections are a common issue, which is due to the increase in friction at the wheel-rail interfaces. For the cases where the wheel-rail interface friction is less than optimum, as in case of high speed trains with very low axle loads, wheel-slips are imminent and loss of traction occurs when the trains accelerate rapidly or brake all of a sudden. These vast variety of traction problems around the wheel-rail interface friction need to be mitigated carefully, so that the contact interface friction neither ascents too high to cause material wear and need for added locomotive power, nor be on the lower side to cause wheel-slips and loss of traction at high speeds. Top-of-rail friction modifiers are engineered surface coatings applied on top of rails, to maintain an optimum frictional contact between the train wheels and the rails. Extensive research works in the area of wheel-rail tribology have revealed that the optimum frictional coefficients at wheel-rail interfaces lie at a value of around 0.35. Application of top-of-rail (TOR) friction modifiers on rail surfaces add an extra layer of material coating on top of the rails, with a surface frictional coefficient of the desired range. This study reviews the common types of rail friction modifiers, the methods for their application, issues related with the application of friction modifiers, and a guideline on selection of the right class of coating material based on site specific requirements of the railway networks.

Impact of realistic communications for fast-acting demand side management

DEFF Research Database (Denmark)

Dambrauskas, Paulius; Syed, Mazheruddin H.; Blair, Steven M.

2017-01-01

The rising penetration of intermittent energy resources is increasing the need for more diverse electrical energy resources that are able to support ancillary services. Demand side management (DSM) has a significant potential to fulfil this role, but several challenges are still impeding the wide......-scale integration of DSM. One of the major challenges is ensuring the performance of the networks that enable communications between control centres and the end DSM resources. This study presents an analysis of all communications networks that typically participate in the activation of DSM, and provides an estimate...... for the overall latency that these networks incur. The most significant sources of delay from each of the components of the communications network are identified which allows the most critical aspects to be determined. This analysis, therefore, offers a detailed evaluation of the performance of DSM resources...

A future Demand Side Management (DSM) opportunity for utility as variable renewable penetrate scale up using agriculture.

Science.gov (United States)

Ines, A.; Bhattacharjee, A.; Modi, V.; Robertson, A. W.; Lall, U.; Kocaman Ayse, S.; Chaudhary, S.; Kumar, A.; Ganapathy, A.; Kumar, A.; Mishra, V.

2015-12-01

Energy demand management, also known as demand side management (DSM), is the modification of consumer demand for energy through various methods such as smart metering, incentive based schemes, payments for turning off loads or rescheduling loads. Usually, the goal of demand side management is to encourage the consumer to use less power during periods of peak demand, or to move the time of energy use to off-peak times. Peak demand management does not necessarily decrease total energy consumption, but could be expected to reduce the need for investments in networks and/or power plants for meeting peak demands. Electricity use can vary dramatically on short and medium time frames, and the pricing system may not reflect the instantaneous cost as additional higher-cost that are brought on-line. In addition, the capacity or willingness of electricity consumers to adjust to prices by altering elasticity of demand may be low, particularly over short time frames. In the scenario of Indian grid setup, the retail customers do not follow real-time pricing and it is difficult to incentivize the utility companies for continuing the peak demand supply. A question for the future is how deeper penetration of renewable will be handled? This is a challenging problem since one has to deal with high variability, while managing loss of load probabilities. In the case of managing the peak demand using agriculture, in the future as smart metering matures with automatic turn on/off for a pump, it will become possible to provide an ensured amount of water or energy to the farmer while keeping the grid energized for 24 hours. Supply scenarios will include the possibility of much larger penetration of solar and wind into the grid. While, in absolute terms these sources are small contributors, their role will inevitably grow but DSM using agriculture could help reduce the capital cost. The other option is of advancing or delaying pump operating cycle even by several hours, will still ensure

Adaptive controller for regenerative and friction braking system

Science.gov (United States)

Davis, Roy I.

1990-01-01

A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

Demand side management for remote area power supply systems incorporating solar irradiance model

International Nuclear Information System (INIS)

Al-Alawi, A.; Islam, S.M.

2004-01-01

This paper presents a technique for generating the daily electricity load profile for remote areas in the Middle East from first principles, using diversified demand. The generated load profile includes the energy required to run a small desalination unit to provide the necessary freshwater. Demand side management (DSM) is used in this study to smooth out the daily peaks and fill valleys in the load curve to make the most efficient use of energy resources. Finally, the load profile is compared with real data for six houses collected from Safri area in the Sultanate of Oman. These data may be used as the basis to obtain load profiles of other remote areas of the Middle East since the weather and social factors are similar. The modified hourly variation factor based on weather and economic and social factors of the Middle East is obtained. (author)

Incentive-compatible demand-side management for smart grids based on review strategies

Science.gov (United States)

Xu, Jie; van der Schaar, Mihaela

2015-12-01

Demand-side load management is able to significantly improve the energy efficiency of smart grids. Since the electricity production cost depends on the aggregate energy usage of multiple consumers, an important incentive problem emerges: self-interested consumers want to increase their own utilities by consuming more than the socially optimal amount of energy during peak hours since the increased cost is shared among the entire set of consumers. To incentivize self-interested consumers to take the socially optimal scheduling actions, we design a new class of protocols based on review strategies. These strategies work as follows: first, a review stage takes place in which a statistical test is performed based on the daily prices of the previous billing cycle to determine whether or not the other consumers schedule their electricity loads in a socially optimal way. If the test fails, the consumers trigger a punishment phase in which, for a certain time, they adjust their energy scheduling in such a way that everybody in the consumer set is punished due to an increased price. Using a carefully designed protocol based on such review strategies, consumers then have incentives to take the socially optimal load scheduling to avoid entering this punishment phase. We rigorously characterize the impact of deploying protocols based on review strategies on the system's as well as the users' performance and determine the optimal design (optimal billing cycle, punishment length, etc.) for various smart grid deployment scenarios. Even though this paper considers a simplified smart grid model, our analysis provides important and useful insights for designing incentive-compatible demand-side management schemes based on aggregate energy usage information in a variety of practical scenarios.

Demand side management for commercial buildings using an in line heat pump water heating methodology

International Nuclear Information System (INIS)

Rankin, Riaan; Rousseau, Pieter G.; Eldik, Martin van

2004-01-01

Most of the sanitary hot water used in South African buildings is heated by means of direct electrical resistance heaters. This is one of the major contributors to the undesirably high morning and afternoon peaks imposed on the national electricity supply grid. For this reason, water heating continues to be of concern to the electricity supplier, ESCOM. Previous studies, conducted by the Potchefstroom University for Christian Higher Education in South Africa, indicated that extensive application of the so called inline heat pump water heating methodology in commercial buildings could result in significant demand side management savings to ESKOM. Furthermore, impressive paybacks can be obtained by building owners who choose to implement the design methodology on existing or new systems. Currently, a few examples exist where the design methodology has been successfully implemented. These installations are monitored with a fully web centric monitoring system that allows 24 h access to data from each installation. Based on these preliminary results, a total peak demand reduction of 108 MW can be achieved, which represents 18% of the peak load reduction target set by ESKOM until the year 2015. This represents an avoided cost of approximately MR324 (ZAR) [Int J Energy Res 25(4) (1999) 2000]. Results based on actual data from the monitored installations shows a significant peak demand reduction for each installation. In one installation, a hotel with an occupancy of 220 people, the peak demand contribution of the hot water installation was reduced by 86%, realizing a 36% reduction in peak demand for the whole building. The savings incurred by the building owner also included significant energy consumption savings due to the superior energy efficiency of the heat pump water heater. The combined savings result in a conservatively calculated straight payback period of 12.5 months, with an internal rate of return of 98%. The actual cost of water heating is studied by

Demand side management—A simulation of household behavior under variable prices

International Nuclear Information System (INIS)

Gottwalt, Sebastian; Ketter, Wolfgang; Block, Carsten; Collins, John; Weinhardt, Christof

2011-01-01

Within the next years, consumer households will be increasingly equipped with smart metering and intelligent appliances. These technologies are the basis for households to better monitor electricity consumption and to actively control loads in private homes. Demand side management (DSM) can be adopted to private households. We present a simulation model that generates household load profiles under flat tariffs and simulates changes in these profiles when households are equipped with smart appliances and face time-based electricity prices. We investigate the impact of smart appliances and variable prices on electricity bills of a household. We show that for households the savings from equipping them with smart appliances are moderate compared to the required investment. This finding is quite robust with respect to variation of tariff price spreads and to different types of appliance utilization patterns. Finally, our results indicate that electric utilities may face new demand peaks when day-ahead hourly prices are applied. However, a considerable amount of residential load is available for shifting, which is interesting for the utilities to balance demand and supply. - Highlights: ► Our model generates residential load profiles that are based on real world data. ► We simulate changes in load profiles when smart appliances and time-of-use tariffs are applied. ► The economic incentive for households to invest in smart appliances is low. ► Time-of-use tariffs create new, even higher peaks. ► Electric utilities have a large amount of the hourly load available for shifting.

The demand-side innovation policies and sustainable development in the small EU country. Nõudluspoolsed innovatsioonipoliitikad ja jätkusuutlik areng Euroopa Liidu väikeriigis

Directory of Open Access Journals (Sweden)

Tõnu Roolaht

2012-01-01

Full Text Available Various regulations, standards, public procurement activities, subsidies for private demand, and other similar support measures form the demand-side innovation policies. In the modern era, countries and governments dedicate more and more attention to the economic, social, and environmental sustainability of development and entrepreneurship. Sustainable development aims to meet human needs so that economic and social conditions will improve or at least not deteriorate and environment is preserved in order to allow future generations to meet their needs as well. Several demand-side innovation policy measures target also sustainability either as primary or secondary goal. Such policy measures tend to suffer from overshooting effects or fail to influence the behaviour in a desired manner. The purpose of this study is to offer suggestions concerning demand-side policy measures in order to improve their impact on the sustainability of development

Demand-side financing measures to increase maternal health service utilisation and improve health outcomes: a systematic review of evidence from low- and middle-income countries.

Science.gov (United States)

Murray, Susan F; Hunter, Benjamin M; Bisht, Ramila; Ensor, Tim; Bick, Debra

2012-01-01

In many countries financing for health services has traditionally been disbursed directly from governmental and non-governmental funding agencies to providers of services: the 'supply-side' of healthcare markets. Demand-side financing offers a supplementary model in which some funds are instead channelled through, or to, prospective users. In this review we considered evidence on five forms of demand-side financing that have been used to promote maternal health in developing countries: OBJECTIVES: The overall review objective was to assess the effects of demand-side financing interventions on maternal health service utilisation and on maternal health outcomes in low- and middle-income countries. Broader effects on perinatal and infant health, the situation of underprivileged women and the health care system were also assessed. This review considered poor, rural or socially excluded women of all ages who were either pregnant or within 42 days of the conclusion of pregnancy, the limit for postnatal care as defined by the World Health Organization. The review also considered the providers of services.The intervention of interest was any programme that incorporated demand-side financing as a mechanism to increase the consumption of goods and services that could impact on maternal health outcomes. This included the direct consumption of maternal health care goods and services as well as related 'merit goods' such as improved nutrition. We included systems in which potential users of maternal health services are financially empowered to make restricted decisions on buying maternal health-related goods or services - sometimes known as consumer-led demand-side financing. We also included programmes that provided unconditional cash benefits to pregnant women (for example in the form of maternity allowances), or to families with children under five years of age where there was evidence concerning maternal health outcomes.We aimed to include quantitative studies (experimental

Increased demand-side flexibility: market effects and impacts on variable renewable energy integration

Directory of Open Access Journals (Sweden)

Åsa Grytli Tveten

2016-12-01

Full Text Available This paper investigates the effect of increased demand-side flexibility (DSF on integration and market value of variable renewable energy sources (VRE. Using assumed potentials, system-optimal within-day shifts in demand are investigated for the Northern European power markets in 2030, applying a comprehensive partial equilibrium model with high temporal and spatial resolution. Increased DSF is found to cause only a minor (less than 3% reduction in consumers’ cost of electricity. VRE revenues are found to increase (up to 5% and 2% for wind and solar power, respectively, and total VRE curtailment decreases by up to 7.2 TWh. Increased DSF causes only limited reductions in GHG emissions. The emission reduction is, however, sensitive to underlying assumptions. We conclude that increased DSF is a promising measure for improving VRE integration. However, low consumers’ savings imply that policies stimulating DFS will be needed to fully use the potential benefits of DSF for VRE integration

Demand-side management project for Tenaga Nasional Berhad. Energy efficiency guidelines. Progress report No. 3. Volume 1. Final report. Export trade information

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-05-01

This study, conducted by the California Energy Commission, was funded by the U.S. Trade and Development Agency. The report summarizes a demand-side management study performed for the Tenaga Nasional Berhad Headquarters Building. The purpose of the study was to identify and evaluate demand side management measures (DSMs) that would reduce energy costs of the facility. Volume 1 is divided into the following sections: (1.0) Executive Summary; (2.0) Facility Background; (3.0) Ventilating and Air Conditioning Systems Description; (4.0) Lightning System Description; Figures, Tables, and Appendices.

Hawaii demand-side management resource assessment. Final report, Reference Volume 1: Building prototype analysis

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-04-01

This report provides a detailed description of, and the baseline assumptions and simulation results for, the building prototype simulations conducted for the building types designated in the Work Plan for Demand-side Management Assessment of Hawaii`s Demand-Side Resources (HES-4, Phase 2). This report represents the second revision to the initial building prototype description report provided to DBEDT early in the project. Modifications and revisions to the prototypes, based on further calibration efforts and on comments received from DBEDT Staff have been incorporated into this final version. These baseline prototypes form the basis upon which the DSM measure impact estimates and the DSM measure data base were developed for this project. This report presents detailed information for each of the 17 different building prototypes developed for use with the DOE-21E program (23 buildings in total, including resorts and hotels defined separately for each island) to estimate the impact of the building technologies and measures included in this project. The remainder of this section presents some nomenclature and terminology utilized in the reports, tables, and data bases developed from this project to denote building type and vintage. Section 2 contains a more detailed discussion of the data sources, the definition of the residential sector building prototypes, and results of the DOE-2 analysis. Section 3 provides a similar discussion for the commercial sector. The prototype and baseline simulation results are presented in a separate section for each building type. Where possible, comparison of the baseline simulation results with benchmark data from the ENERGY 2020 model or other demand forecasting models specific to Hawaii is included for each building. Appendix A contains a detailed listing of the commercial sector baseline indoor lighting technologies included in the existing and new prototypes by building type.

Friction effects on lateral loading behavior of rigid piles

DEFF Research Database (Denmark)

Zania, Varvara; Hededal, Ole

2012-01-01

taking into account the shear frictional resistance along the pile. For this purpose efficient three dimensional finite element models of different diameter have been developed. The increase of the side friction and of the diameter of the pile is shown to alter the failure pattern and increase...... the lateral capacity of the pile. The obtained p - y curves demonstrate the importance of the aforementioned parameters in the design of rigid piles, as the reduction of friction along the interface reduces not only the ultimate load but also the stiffness of the soil-pile response. Read More: http...

Distributed Optimisation Algorithm for Demand Side Management in a Grid-Connected Smart Microgrid

Directory of Open Access Journals (Sweden)

Omowunmi Mary Longe

2017-06-01

Full Text Available The contributions of Distributed Energy Generation (DEG and Distributed Energy Storage (DES for Demand Side Management (DSM purposes in a smart macrogrid or microgrid cannot be over-emphasised. However, standalone DEG and DES can lead to under-utilisation of energy generation by consumers and financial investments; in grid-connection mode, though, DEG and DES can offer arbitrage opportunities for consumers and utility provider(s. A grid-connected smart microgrid comprising heterogeneous (active and passive smart consumers, electric vehicles and a large-scale centralised energy storage is considered in this paper. Efficient energy management by each smart entity is carried out by the proposed Microgrid Energy Management Distributed Optimisation Algorithm (MEM-DOA installed distributively within the network according to consumer type. Each smart consumer optimises its energy consumption and trading for comfort (demand satisfaction and profit. The proposed model was observed to yield better consumer satisfaction, higher financial savings, and reduced Peak-to-Average-Ratio (PAR demand on the utility grid. Other associated benefits of the model include reduced investment on peaker plants, grid reliability and environmental benefits. The MEM-DOA also offered participating smart consumers energy and tariff incentives so that passive smart consumers do not benefit more than active smart consumers, as was the case with some previous energy management algorithms.

Effect of microstructural variation on the Cu/CK45 carbon steel friction weld joint

Energy Technology Data Exchange (ETDEWEB)

Lee, W.B.; Jung, S.B. [Advanced Materials and Process Research Center for IT, Sungkyunkwan Univ., Gyounggi-do (Korea)

2003-12-01

The mechanical properties of friction-welded pure Cu/CK45 carbon steel joints have been studied. The joint strength increased with increasing upset pressure till it reached a critical value. However, the joint strength was fixed at a low strength with increasing friction time, compared to that of the Cu base metal. The hardness near the interface at the Cu side was softer than that of the base metal due to the dynamically recrystallized and annealed grain. The width of the softened region became wider with increasing friction time and decreasing upset pressure. But the hardness of the CK45 carbon steel side showed a slightly higher value than that of the base metal. This result was explained by the formation of martensite structure at the CK45 carbon steel side during the welding process. (orig.)

Skin friction on a flat perforated acoustic liner

Science.gov (United States)

Boldman, D. R.; Brinich, P. F.

1976-01-01

The report concerns the measurement of friction coefficients of a typical perforated acoustic liner installed in the side of a wind tunnel. The results are compared with measured friction coefficients of a smooth hard wall for the same mean flow velocities in a wind tunnel. At a velocity of 61 m/sec, an increase in the local skin coefficient of only a few percent was observed, but at the highest velocity of 213 m/sec an increase of about 20% was obtained. This velocity is a realistic velocity for turbo-machinery components utilizing such liners, so a loss in performance is to be expected. Some tests were also performed to see if changes in the mean boundary layer induced by imposed noise would result in friction increase, but only at low velocity levels was such an increase in friction noted.

Effects of utility demand-side management programs on uncertainty

International Nuclear Information System (INIS)

Hirst, E.

1994-01-01

Electric utilities face a variety of uncertainties that complicate their long-term resource planning. These uncertainties include future economic and load growths, fuel prices, environmental and economic regulations, performance of existing power plants, cost and availability of purchased power, and the costs and performance of new demand and supply resources. As utilities increasingly turn to demand-side management (DSM) programs to provide resources, it becomes more important to analyze the interactions between these programs and the uncertainties facing utilities. This paper uses a dynamic planning model to quantify the uncertainty effects of supply-only vs DSM + supply resource portfolios. The analysis considers four sets of uncertainties: economic growth, fuel prices, the costs to build new power plants, and the costs to operate DSM programs. The two types of portfolios are tested against these four sets of uncertainties for the period 1990 to 2010. Sensitivity, scenario, and worst-case analysis methods are used. The sensitivity analyses show that the DSM + supply resource portfolio is less sensitive to unanticipated changes in economic growth, fuel prices, and power-plant construction costs than is the supply-only portfolio. The supply-only resource mix is better only with respect to uncertainties about the costs of DSM programs. The base-case analysis shows that including DSM programs in the utility's resource portfolio reduces the net present value of revenue requirements (NPV-RR) by 490 million dollars. The scenario-analysis results show an additional 30 million dollars (6%) in benefits associated with reduction in these uncertainties. In the worst-case analysis, the DSM + supply portfolio again reduces the cost penalty associated with guessing wrong for both cases, when the utility plans for high needs and learns it has low needs and vice versa. 20 refs

Demand-Side Financing in Education: a Critical Examination of a Girls' Scholarship Program in Malawi--(Case Study)

Science.gov (United States)

Sineta, Abraham

2012-01-01

Despite the push for universal education, many disadvantaged and poor children in developing countries still do not have access to basic education. This among other reasons is due to poverty where poor families cannot afford the cost of basic education even when it is "free" of tuition (McDonald, 2007). Demand-side financing…

Proceedings of the CEATI demand side management workshop on understanding customer response. CD-ROM ed.

International Nuclear Information System (INIS)

2006-01-01

Demand for electricity continues to increase in the midst of environmental concerns, deregulation and the rapid evolution of technology. In order to succeed in a changing environment, utilities must be both adaptive and innovative. Growing concerns over supply and the environmental effects of rising consumption rates have led many utilities to establish demand side management (DSM) programs. However, some utilities have failed to consider the importance of customer behaviour in the success of DSM programs. This conference examined various successful initiatives to encourage customers to reduce their individual or corporate demands for energy. The influence of branding, technology, information prices signals and various other strategies were explored. Issues concerning energy efficiency and customer feedback were discussed. The effect of alternative pricing regimes on DSM programs was investigated. Various information system tools were also examined, and the value of real time electricity monitoring was evaluated. Various DSM initiatives in North America were used to establish benchmarks for the successful implementation of DSM strategies. The conference was divided into 3 sessions: (1) involving the customer in reducing demand; (2) the success of energy efficiency and demand response programs : the impact of branding and the impact of price signals; and (3) the technologies and innovations needed to make it work. The conference featured 13 presentations, of which 8 have been catalogued separately for inclusion in this database. refs., tabs., figs

Proceedings of the CEATI demand side management workshop on understanding customer response. CD-ROM ed.

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

Demand for electricity continues to increase in the midst of environmental concerns, deregulation and the rapid evolution of technology. In order to succeed in a changing environment, utilities must be both adaptive and innovative. Growing concerns over supply and the environmental effects of rising consumption rates have led many utilities to establish demand side management (DSM) programs. However, some utilities have failed to consider the importance of customer behaviour in the success of DSM programs. This conference examined various successful initiatives to encourage customers to reduce their individual or corporate demands for energy. The influence of branding, technology, information prices signals and various other strategies were explored. Issues concerning energy efficiency and customer feedback were discussed. The effect of alternative pricing regimes on DSM programs was investigated. Various information system tools were also examined, and the value of real time electricity monitoring was evaluated. Various DSM initiatives in North America were used to establish benchmarks for the successful implementation of DSM strategies. The conference was divided into 3 sessions: (1) involving the customer in reducing demand; (2) the success of energy efficiency and demand response programs : the impact of branding and the impact of price signals; and (3) the technologies and innovations needed to make it work. The conference featured 13 presentations, of which 8 have been catalogued separately for inclusion in this database. refs., tabs., figs.

Demand- and supply-side determinants of diphtheria-pertussis-tetanus nonvaccination and dropout in rural India.

Science.gov (United States)

Ghosh, Arpita; Laxminarayan, Ramanan

2017-02-15

Although 93% of 12- to 23-month-old children in India receive at least one vaccine, typically Bacillus Calmette-Guérin, only 75% complete the recommended three doses of diphtheria-pertussis-tetanus (DPT, also referred to as DTP) vaccine. Determinants can be different for nonvaccination and dropout but have not been examined in earlier studies. We use the three-dose DPT series as a proxy for the full sequence of recommended childhood vaccines and examine the determinants of DPT nonvaccination and dropout between doses 1 and 3. We analyzed data on 75,728 6- to 23-month-old children in villages across India to study demand- and supply-side factors determining nonvaccination with DPT and dropout between DPT doses 1 and 3, using a multilevel approach. Data come from the District Level Household and Facility Survey 3 (2007-08). Individual- and household-level factors were associated with both DPT nonvaccination and dropout between doses 1 and 3. Children whose mothers had no schooling were 2.3 times more likely not to receive any DPT vaccination and 1.5 times more likely to drop out between DPT doses 1 and 3, compared with children whose mothers had 10 or more years of schooling. Although supply-side factors related to availability of public health facilities and immunization-related health workers in villages were not correlated with dropout between DPT doses 1 and 3, children in districts where 46% or more villages had a healthcare subcentre were 1.5 times more likely to receive at least one dose of DPT vaccine compared with children in districts where 30% or fewer villages had subcentres. Nonvaccination with DPT in India is influenced by village- and district-level contextual factors over and above individuals' background characteristics. Dropout between DPT doses 1 and 3 is associated more strongly with demand-side factors than with village- and district-level supply-side factors. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Demand-side management (DSM) in the context of China's on-going power sector reform

International Nuclear Information System (INIS)

Zhang, Sufang; Jiao, Yiqian; Chen, Wenjun

2017-01-01

As an approach to manage power demand-side resources, DSM plays an important role in electric power system. Though DSM was introduced into China in the early 1990s, its benefits have been underutilized. Using literature study, interview methods and three data sources, this paper examines the likely impacts of China's on-going power sector reform on its DSM. It finds that the major constraints to DSM in China are the insufficient and improper market-based DSM mechanism, grid companies’ low motivations for DSM due to their traditional business model, the underdeveloped energy service industry, and electricity end-users’ low motivation for DSM. China's on-going power sector reform will change power transmission and distribution pricing and grid companies’ business model and introduce competition into retail-side. Drawing on these findings, it is concluded that the likely impacts of the new reform on DSM are: governments may attach more importance to DSM; grid companies may have more motivations for DSM investment; electricity end-users’ motivations for DSM may be both enhanced and dampened; electricity retailers’ motivations for DSM may be dampened; demand response application may be enhanced, and more DSM business models may be developed. Finally, policy implications are provided. - Highlights: • Mechanism of and constraints to DSM in China are examined. • China’s on-going power sector reform is overviewed. • DSM is likely to be enhanced under China's on-going power sector reform. • Policy implications are provided.

Demand-side management project for Tenaga Nasional Berhad. Progress report No. 4. Export trade information

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

This study, conducted by the California Energy Commission, was funded by the U.S. Trade and Development Agency. Progress Report No. 4 is divided into the following contents: April 6, 1994 Training Mission Delegation Itinerary; April 6, 1994 Training Mission Workshop Information Package; Letter to Chairman of Tenaga Nasional Berhad Requesting Demonstration Project Funding; Design/Build Construction Bid Proposal for Energy Efficient Electric Technology Demontration Project; Final Draft of Demand-Side Management Plan for Tenaga Nasional Berhad; Attachments.

Methodology for the analysis and characterization of the demand side energy resources; Metodologia para analise e caracterizacao dos recursos energeticos do lado da demanda

Energy Technology Data Exchange (ETDEWEB)

Baitelo, Ricardo Lacerda; Udaeta, Miguel Edgar Morales [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Energia e Automacao Eletricas. Grupo de Energia; Burani, Geraldo Francisco; Grimoni, Jose Aquiles Baesso [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Energia e Eletrotecnica

2006-07-01

This abstract aims at describing briefly a model for the assessment of demand side energy resources This model intends to comprehend every kind of action and measure related to demand side management and energy conservation, evaluating them in a holistic way, into four dimensions: technical-economical, environmental, social and political. Different aspects regarding the resources are also accounted, such as energetic potentials (theoretical, accomplishable and economic). At last, scenarios concerning the introduction of evaluated resources through a period of time are elaborated. (author)

DEVELOPMENT OF THE E-GOVERNMENT MARKET IN THE EUROPEAN UNION: AN ANALYSIS OF THE SUPPLY VERSUS DEMAND SIDES

Directory of Open Access Journals (Sweden)

Veghes Calin

2011-07-01

Full Text Available E-government represents one of the most palpable results of the dynamic development of the information and communication technology. Defined mostly as an intensive use of information technologies to provide public services, e-government has been approached in the literature rather from a technological perspective, with a significant importance given to the supply and a lower attention paid to the demand side. The increasing interest in taking into consideration the demand side in the development of the e-government initiatives and projects has created the foundation for a shift in the way the conceptual framework for e-government planning and implementation is defined, from the technology infrastructure and costs to the customer-centric character of all the efforts done. The European Union put e-government on its agenda aiming to improve access to the public information and services, increase transparency of public administration, exploit effectively the information technology within public administration, and establishing e-procurement. The development of the e-government services in the Member States, as it is expressed by the data regarding the supply and demand side, has been conducted in a more or less different manner that led, at the Unions level, to a relatively high availability but a rather low usage of the specific services. The paper explores the relationship between the e-government supply and demand based on the secondary data referring to the public services available to the citizens (as these are defined by the Eurostat methodology and the usage of these services by the individuals, integrating them through an analytical matrix inspired by the BCG model. Probably the most important conclusion of this analysis states that development of the e-government services has not been accompanied by measures meant to stimulate their usage in the most of the European Union Member States. The analytical matrix allowed also the identification

Multiple pass and multiple layer friction stir welding and material enhancement processes

Science.gov (United States)

Feng, Zhili [Knoxville, TN; David, Stan A [Knoxville, TN; Frederick, David Alan [Harriman, TN

2010-07-27

Processes for friction stir welding, typically for comparatively thick plate materials using multiple passes and multiple layers of a friction stir welding tool. In some embodiments a first portion of a fabrication preform and a second portion of the fabrication preform are placed adjacent to each other to form a joint, and there may be a groove adjacent the joint. The joint is welded and then, where a groove exists, a filler may be disposed in the groove, and the seams between the filler and the first and second portions of the fabrication preform may be friction stir welded. In some embodiments two portions of a fabrication preform are abutted to form a joint, where the joint may, for example, be a lap joint, a bevel joint or a butt joint. In some embodiments a plurality of passes of a friction stir welding tool may be used, with some passes welding from one side of a fabrication preform and other passes welding from the other side of the fabrication preform.

Integrated design and evaluation of biomass energy system taking into consideration demand side characteristics

International Nuclear Information System (INIS)

Ren, Hongbo; Zhou, Weisheng; Nakagami, Ken'ichi; Gao, Weijun

2010-01-01

In this paper, a linear programming model has been developed for the design and evaluation of biomass energy system, while taking into consideration demand side characteristics. The objective function to be minimized is the total annual cost of the energy system for a given customer equipped with a biomass combined cooling, heating and power (CCHP) plant, as well as a backup boiler fueled by city gas. The results obtained from the implementation of the model demonstrate the optimal system capacities that customers could employ given their electrical and thermal demands. As an illustrative example, an investigation addresses the optimal biomass CCHP system for a residential area located in Kitakyushu Science and Research Park, Japan. In addition, sensitivity analyses have been elaborated in order to show how the optimal solutions would vary due to changes of some key parameters including electricity and city gas tariffs, biogas price, electricity buy-back price, as well as carbon tax rate. (author)

Employee retention and integrated disability management practices as demand side factors.

Science.gov (United States)

Habeck, Rochelle; Hunt, Allan; Rachel, Colleen Head; Kregel, John; Chan, Fong

2010-12-01

Demand-side employment research on company policies and practices related to retention and absence and disability management (ADM) can contribute to our understanding of employment issues related to people with disabilities from the employers' perspective. To examine company ADM and retention practices and their effectiveness, as well as how these company policies and practices might influence hiring of people with disabilities. Disability Management Employer Coalition employer members (N = 650) were surveyed by internet and the survey data were analyzed using descriptive statistics, correlation, and multiple regression. Ninety-five participants responded to the survey resulting in a response rate of 14%. Retention practice was found to be associated with retention effectiveness (r = .39, P ideas and involvement of employees, and assuring they know how their work and performance support the mission. ADM practice was related to improving health and managing health conditions (r = .26, P companies.

Demand-Side Flexibility for Energy Transitions: Ensuring the Competitive Development of Demand Response Options

OpenAIRE

Nursimulu, Anjali; Florin, Marie-Valentine; Vuille, François

2015-01-01

This report provides an overview of the current debates about demand response development, focusing primarily on Europe, with some comparisons to the United States. ‘Demand response’ includes strategies that involve end-use customers adapting or altering their electricity demand in response to grid conditions or market prices. It is viewed as a multi-purpose power-system resource that enhances the energy system’s capacity to cope with increasing demand, rising costs of conventional transmissi...

Albedo and vegetation demand-side management options for warm climates

International Nuclear Information System (INIS)

Hall, Darwin C.

1997-01-01

For electric utilities, demand-side management (DSM) can reduce electric load and shift load from peak to off-peak periods. In general, the investor in DSM collects the reward with lower electric bills, excepting a positive externality because of reduced tropospheric and stratospheric air pollution from fossil fuel power plants. In warm climates, DSM options include increasing albedo and vegetation, respectively, by painting surfaces white and planting trees; these DSM options are distinguished from all other DSM options because of ecosystem effects. Ambient temperature falls, mitigating the urban 'heat island', which reduces electric load and ozone formation. The investor in albedo and vegetation DSM options does not collect all of the reward from lower electric bills, since the lower ambient temperature provides savings to all customers who use electricity for air conditioning and refrigeration. Similar to other DSM options, air pollution is also reduced as a result of lower power plant emissions. Complex airshed models and electric utility system dispatch models are applied in this paper to account for some of these ecosystem effects. Unaccounted ecosystem effects remain, stymieing cost effectiveness analysis

DEMONSTRATION OF THE ENVIRONMENTAL AND DEMAND-SIDE MANAGEMENT BENEFITS OF GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEMS SITED ON MILITARY BASES

Science.gov (United States)

The report gives results of an investigation into the pollutant emission reduction and demand-side management potential of three photovoltaic (PV) systems installed at Ft. Huachuca, AZ, Ft. Dix, NJ, and Hickam Air Force Base, HI, which began operation between January and July 199...

Communications technologies for demand side management, DSM, and European utility communications architecture, EurUCA

Energy Technology Data Exchange (ETDEWEB)

Uuspaeae, P. [VTT Energy, Espoo (Finland)

1996-12-31

The scope of this research is data communications for electric utilities. Demand Side Management (DSM) calls for communication between the Electric Utility and the Customer. The communication capacity needed will depend on the functions that are chosen for DSM, and on the number of customers. Some functions may be handled with one-way communications, some functions require two-way communication. Utility Communication Architecture looks for an overall view of the communications needs and communication systems in an electric utility. The objective is to define and specify suitable and compatible communications procedures within the Utility and also to outside parties. (27 refs.)

Communications technologies for demand side management, DSM, and European utility communications architecture, EurUCA

Energy Technology Data Exchange (ETDEWEB)

Uuspaeae, P [VTT Energy, Espoo (Finland)

1997-12-31

The scope of this research is data communications for electric utilities. Demand Side Management (DSM) calls for communication between the Electric Utility and the Customer. The communication capacity needed will depend on the functions that are chosen for DSM, and on the number of customers. Some functions may be handled with one-way communications, some functions require two-way communication. Utility Communication Architecture looks for an overall view of the communications needs and communication systems in an electric utility. The objective is to define and specify suitable and compatible communications procedures within the Utility and also to outside parties. (27 refs.)

Analysis of Cool Roof Coatings for Residential Demand Side Management in Tropical Australia

Directory of Open Access Journals (Sweden)

Wendy Miller

2015-06-01

Full Text Available Cool roof coatings have a beneficial impact on reducing the heat load of a range of building types, resulting in reduced cooling energy loads. This study seeks to understand the extent to which cool roof coatings could be used as a residential demand side management (DSM strategy for retrofitting existing housing in a constrained network area in tropical Australia where peak electrical demand is heavily influenced by residential cooling loads. In particular this study seeks to determine whether simulation software used for building regulation purposes can provide networks with the ‘impact certainty’ required by their DSM principles. The building simulation method is supported by a field experiment. Both numerical and experimental data confirm reductions in total consumption (kWh and energy demand (kW. The nature of the regulated simulation software, combined with the diverse nature of residential buildings and their patterns of occupancy, however, mean that simulated results cannot be extrapolated to quantify benefits to a broader distribution network. The study suggests that building data gained from regulatory simulations could be a useful guide for potential impacts of widespread application of cool roof coatings in this region. The practical realization of these positive impacts, however, would require changes to the current business model for the evaluation of DSM strategies. The study provides seven key recommendations that encourage distribution networks to think beyond their infrastructure boundaries, recognising that the broader energy system also includes buildings, appliances and people.

Demand-side mitigation options of the agricultural sector: potential, barriers and ways forward

Directory of Open Access Journals (Sweden)

Brunelle Thierry

2017-01-01

Full Text Available This paper reviews the potential and barriers of demand-side mitigation options in the agricultural sector based on the recent academic literature and on a survey conducted on a sample of 788 respondents living in France. The mitigation potential of such measures as reducing losses in the food supply chain and shifting diets toward less animal products is estimated to be particularly high, higher, in particular, than supply-side mitigation options. However, to ensure that these measures do not entail a reduction in protein intake, these estimations should consider both caloric and protein units, and take into account the digestibility differentials between protein sources. Our survey shows that people are relatively reluctant to eat more sustainably, preferring to reduce their emissions in other areas such as housing or equipment. This relative reluctance is mainly due to individual perceptions linked to health concerns, taste or habits. Some obstacles could easily be overcome through well-designed policies aiming to, for example, advertise a lower consumption of red meat for health benefits. National governments are, however, rather inactive on this topic, leaving the initiative to the civil society.

Dry friction of microstructured polymer surfaces inspired by snake skin

Directory of Open Access Journals (Sweden)

Martina J. Baum

2014-07-01

Full Text Available The microstructure investigated in this study was inspired by the anisotropic microornamentation of scales from the ventral body side of the California King Snake (Lampropeltis getula californiae. Frictional properties of snake-inspired microstructured polymer surface (SIMPS made of epoxy resin were characterised in contact with a smooth glass ball by a microtribometer in two perpendicular directions. The SIMPS exhibited a considerable frictional anisotropy: Frictional coefficients measured along the microstructure were about 33% lower than those measured in the opposite direction. Frictional coefficients were compared to those obtained on other types of surface microstructure: (i smooth ones, (ii rough ones, and (iii ones with periodic groove-like microstructures of different dimensions. The results demonstrate the existence of a common pattern of interaction between two general effects that influence friction: (1 molecular interaction depending on real contact area and (2 the mechanical interlocking of both contacting surfaces. The strongest reduction of the frictional coefficient, compared to the smooth reference surface, was observed at a medium range of surface structure dimensions suggesting a trade-off between these two effects.

Dry friction of microstructured polymer surfaces inspired by snake skin.

Science.gov (United States)

Baum, Martina J; Heepe, Lars; Fadeeva, Elena; Gorb, Stanislav N

2014-01-01

The microstructure investigated in this study was inspired by the anisotropic microornamentation of scales from the ventral body side of the California King Snake (Lampropeltis getula californiae). Frictional properties of snake-inspired microstructured polymer surface (SIMPS) made of epoxy resin were characterised in contact with a smooth glass ball by a microtribometer in two perpendicular directions. The SIMPS exhibited a considerable frictional anisotropy: Frictional coefficients measured along the microstructure were about 33% lower than those measured in the opposite direction. Frictional coefficients were compared to those obtained on other types of surface microstructure: (i) smooth ones, (ii) rough ones, and (iii) ones with periodic groove-like microstructures of different dimensions. The results demonstrate the existence of a common pattern of interaction between two general effects that influence friction: (1) molecular interaction depending on real contact area and (2) the mechanical interlocking of both contacting surfaces. The strongest reduction of the frictional coefficient, compared to the smooth reference surface, was observed at a medium range of surface structure dimensions suggesting a trade-off between these two effects.

On friction braking demand with regenerative braking

NARCIS (Netherlands)

Walker, A.M.; Lampérth, M.U.; Wilkins, S.

2002-01-01

Developments in Hybrid Electric and pure Electric Vehicles are intended to improve the operational efficiency of road vehicles. Regenerative braking, which has long been established in rail vehicles, is integral to efficiency improvement, with up to 30% of overall traction energy demand satisfied by

Developing a demand side management strategic framework through a collaborative [process

International Nuclear Information System (INIS)

Kostler, J.

1992-01-01

Alberta Power Ltd. is developing a demand side management (DSM) strategic framework through a collaborative process that began in September 1991. The process is seen to have the advantages of involving customers in DSM issues, giving them the opportunity to determine the outcome, being less confrontational, and having the capability of arriving at solutions unattainable through other processes. Issues being considered in the collaborative process include cost effectiveness, externalities, screening and analyzing of DSM measures, cost allocation and recovery, DSM lost revenues, the utility role in DSM, measurement criteria, and incentives. The process includes day-long meetings of a 12-member collaborative group comprising representatives from Alberta Power, government agencies, industry and municipal associations, and environmental and consumer organizations. A professional facilitator and an expert consultant from outside Alberta Power were employed to support the collaborative process. The process is working well and is on track to present the utility with a strategic framework to deal with DSM

A scoping study: demand side measures on the UK electrical system

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The study is intended to eventually bring about a number of improvements in the UK electrical system, particularly in regard to Demand Side Management (DSM). Among the benefits envisaged are (a) increased security of supply when the network is under stress; (b) reduction in costs; (c) simpler outage management; (d) carbon saving and (e) increased energy efficiency. So far, these potential benefits have attracted little attention in the residential and small business sectors of the market: suggested reasons for this are listed. Taking into account the experience of other countries, three options are presented for a UK DSM programme: they are (i) customer initiated; (ii) supplier initiated and (iii) distributor initiated. At present, all the suggested options need further study and to aid the development for small customers, five possible initiatives are suggested. This final report (95 pages) includes a detailed description of the research required and a tender process for a customer-initiated programme. The report was prepared by KEMA Limited under contract to the DTI.

A scoping study: demand side measures on the UK electrical system

International Nuclear Information System (INIS)

2005-01-01

The study is intended to eventually bring about a number of improvements in the UK electrical system, particularly in regard to Demand Side Management (DSM). Among the benefits envisaged are (a) increased security of supply when the network is under stress; (b) reduction in costs; (c) simpler outage management; (d) carbon saving and (e) increased energy efficiency. So far, these potential benefits have attracted little attention in the residential and small business sectors of the market: suggested reasons for this are listed. Taking into account the experience of other countries, three options are presented for a UK DSM programme: they are (i) customer initiated; (ii) supplier initiated and (iii) distributor initiated. At present, all the suggested options need further study and to aid the development for small customers, five possible initiatives are suggested. This final report (95 pages) includes a detailed description of the research required and a tender process for a customer-initiated programme. The report was prepared by KEMA Limited under contract to the DTI

A socio-technical investigation of the smart grid: Implications for demand-side activities of electricity service providers

Science.gov (United States)

Corbett, Jacqueline Marie

Enabled by advanced communication and information technologies, the smart grid represents a major transformation for the electricity sector. Vast quantities of data and two-way communications abilities create the potential for a flexible, data-driven, multi-directional supply and consumption network well equipped to meet the challenges of the next century. For electricity service providers ("utilities"), the smart grid provides opportunities for improved business practices and new business models; however, a transformation of such magnitude is not without risks. Three related studies are conducted to explore the implications of the smart grid on utilities' demand-side activities. An initial conceptual framework, based on organizational information processing theory, suggests that utilities' performance depends on the fit between the information processing requirements and capacities associated with a given demand-side activity. Using secondary data and multiple regression analyses, the first study finds, consistent with OIPT, a positive relationship between utilities' advanced meter deployments and demand-side management performance. However, it also finds that meters with only data collection capacities are associated with lower performance, suggesting the presence of information waste causing operational inefficiencies. In the second study, interviews with industry participants provide partial support for the initial conceptual model, new insights are gained with respect to information processing fit and information waste, and "big data" is identified as a central theme of the smart grid. To derive richer theoretical insights, the third study employs a grounded theory approach examining the experience of one successful utility in detail. Based on interviews and documentary data, the paradox of dynamic stability emerges as an essential enabler of utilities' performance in the smart grid environment. Within this context, the frames of opportunity, control, and data

Development of Microstructure and Crystallographic Texture in a Double-Sided Friction Stir Welded Microalloyed Steel

Science.gov (United States)

Rahimi, S.; Wynne, B. P.; Baker, T. N.

2017-01-01

The evolution of microstructure and crystallographic texture has been investigated in double-sided friction stir welded microalloyed steel, using electron backscatter diffraction (EBSD). The microstructure analyses show that the center of stirred zone reached a temperature between Ac1 and Ac3 during FSW, resulting in a dual-phase austenitic/ ferritic microstructure. The temperatures in the thermo-mechanically affected zone and the overlapped area between the first and second weld pass did not exceed the Ac1. The shear generated by the rotation probe occurs in austenitic/ferritic phase field where the austenite portion of the microstructure is transformed to a bainitic ferrite, on cooling. Analysis of crystallographic textures with regard to shear flow lines generated by the probe tool shows the dominance of simple shear components across the whole weld. The austenite texture at Ac1 - Ac3 is dominated by the B { {1bar{1}2} }D2 { {11bar{2}} }< 111rangle simple shear texture components. The formation of ultrafine equiaxed ferrite with submicron grain size has been observed in the overlapped area between the first and second weld pass. This is due to continuous dynamic strain-induced recrystallization as a result of simultaneous severe shear deformation and drastic undercooling.

Demand Side Management in an Integrated Electricity Market: What are the Impacts on Generation and Environmental Concerns?

International Nuclear Information System (INIS)

Bergaentzle, Claire; Clastres, Cedric

2013-05-01

Smart Grid technology appears necessary to succeed in activating the demand through demand side management (DSM) programs. This would in turn improve energy efficiency and achieve environmental targets through controlled consumption. The many pilot projects led worldwide involving smart grids technology, brought quantitative evaluations of DSM measures on electricity load. Efficient DSM instruments must be fine-tuned to respond to very specific issues arising from the generation mix, the integration of intermittent energies or the level of outage risks faced during peak period. Efficient DSM strategies are illustrated through a model involving five countries that carry these different features and under the assumptions of isolated and fully interconnected markets. This paper aims at bringing recommendations regarding the instruments that should be implemented to maximize the benefits of smart grids technology and demand response. Finally, it tends to emphasis the issue of homogenized energy efficiency policies, critical in the building of internal energy markets such as the one the European Union is envisioning. (authors)

Report of the advisory group on demand-side management and demand response in Ontario in response to the Minister's directive to the Ontario Energy Board

International Nuclear Information System (INIS)

2003-01-01

The Ontario Energy Board was directed in June 2003 to consult with stakeholders to identify and review options for the delivery of demand-side management (DSM) and demand response (DR) activities within the electricity sector, including the role of local distribution companies (distributors) in such activities. A total of 118 stakeholders participated in the consultation process, and 31 representatives from all sectors were then invited to take part in an advisory working group to develop options to be considered by the Board when preparing the recommendations to the Minister. This report presents a consolidation of the Group's working documents and the results of deliberations both as a unit and in small groups. The best way to present the many newly developed models was as a single Central Agency model demonstrating variations in the role of the Central Agency and other players in the electricity market. The paper was divided into the following six sections: introduction; market issues; demand response framework option; central agency framework-alternative models; Ontario Energy Board-wires companies DSM framework; and, general issues

Distributed demand-side management optimisation for multi-residential users with energy production and storage strategies

Directory of Open Access Journals (Sweden)

Emmanuel Chifuel Manasseh

2014-12-01

Full Text Available This study considers load control in a multi-residential setup where energy scheduler (ES devices installed in smart meters are employed for demand-side management (DSM. Several residential end-users share the same energy source and each residential user has non-adjustable loads and adjustable loads. In addition, residential users may have storage devices and renewable energy sources such as wind turbines or solar as well as dispatchable generators. The ES devices exchange information automatically by executing an iterative distributed algorithm to locate the optimal energy schedule for each end-user. This will reduce the total energy cost and the peak-to-average ratio (PAR in energy demand in the electric power distribution. Users possessing storage devices and dispatchable generators strategically utilise their resources to minimise the total energy cost together with the PAR. Simulation results are provided to evaluate the performance of the proposed game theoretic-based distributed DSM technique.

Why strategic pricing is the most powerful DSM [demand-side management] tool

International Nuclear Information System (INIS)

LeBlanc, W.

1990-01-01

Strategic pricing has long been under-utilized as a strategic tool by the electric utility industry. Ways by which utility, customer and regulatory interests can and should overlap with reference to strategic planning, and how the electric industry could enhance its ability to continue providing premier energy services to its customers and society are examined. Strategic pricing in the airline, banking, automobile and telephone industries are examined and compared. Strategic pricing can help utilities segment markets to improve service value, define products, create customer incentives to purchase/consume desirable goods and services, and signal competitors. Each of these benefits is illustrated with an example that closely integrates strategic pricing with demand-side management. Pricing strategically takes many steps, but can be broken down into: meet common challenges of business and marketing objectives; gain regulatory acceptance; and energize the organization to accept, adopt and implement strategic pricing

Demand-side management process evaluations - the management perspective

International Nuclear Information System (INIS)

Perrault, G.A.; Barrett, L.B.

1993-01-01

A demand-side management (DSM) process evaluation is a qualitative, expert assessment of how a utility marketing program is being conducted. It reviews the efficiency and effectiveness in which a utility plans, manages, executes, and monitors the delivery of DSM programs to its marketplace. Process evaluations,which includes load impact, customer satisfaction and cost-effectiveness analysis, are becoming an increasingly significant component. The process evaluation focus is on the program planning and delivery process as opposed to the energy impacts resulting from the specific measures or products of the program. Because of this process-oriented focus, such evaluations can identify important opportunities for improving the cost-effectiveness of a program without significantly changing product lines. The evaluation may identify administrative or delivery process improvements. In addition, the evaluation may identify ways of improving the degree to which the customer is satisfied with the program or the utility. Since process evaluations are usually conducted as part of a utility's mandated DSM measurement and evaluation plan, they tend to focus mainly on the stated needs of the regulator as opposed to company management. This can be a problem. Although the regulatory perspective is important, in an increasingly competitive business environment, utilities must not overlook management's business and operational needs for specific information regarding DSM program planning, control, execution, and evaluation. This paper discusses some of the conflicts that exist between the regulator's and management's needs for DSM program evaluation results and presents some approaches for assuring that both needs are met. It is organized to first discuss the scope of a process evaluation, then the evaluation issues, the management concerns, and finally reporting of results

Impacts of Demand-Side Resources on Electric Transmission Planning

Energy Technology Data Exchange (ETDEWEB)

Hadley, Stanton W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sanstad, Alan H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2015-01-01

Will demand resources such as energy efficiency (EE), demand response (DR), and distributed generation (DG) have an impact on electricity transmission requirements? Five drivers for transmission expansion are discussed: interconnection, reliability, economics, replacement, and policy. With that background, we review the results of a set of transmission studies that were conducted between 2010 and 2013 by electricity regulators, industry representatives, and other stakeholders in the three physical interconnections within the United States. These broad-based studies were funded by the US Department of Energy and included scenarios of reduced load growth due to EE, DR, and DG. While the studies were independent and used different modeling tools and interconnect-specific assumptions, all provided valuable results and insights. However, some caveats exist. Demand resources were evaluated in conjunction with other factors, and limitations on transmission additions between scenarios made understanding the role of demand resources difficult. One study, the western study, included analyses over both 10- and 20-year planning horizons; the 10-year analysis did not show near-term reductions in transmission, but the 20-year indicated fewer transmission additions, yielding a 36percent capital cost reduction. In the eastern study the reductions in demand largely led to reductions in local generation capacity and an increased opportunity for low-cost and renewable generation to export to other regions. The Texas study evaluated generation changes due to demand, and is in the process of examining demand resource impacts on transmission.

Aggregated Demand Modelling Including Distributed Generation, Storage and Demand Response

OpenAIRE

Marzooghi, Hesamoddin; Hill, David J.; Verbic, Gregor

2014-01-01

It is anticipated that penetration of renewable energy sources (RESs) in power systems will increase further in the next decades mainly due to environmental issues. In the long term of several decades, which we refer to in terms of the future grid (FG), balancing between supply and demand will become dependent on demand actions including demand response (DR) and energy storage. So far, FG feasibility studies have not considered these new demand-side developments for modelling future demand. I...

An Overview of Demand Side Management Control Schemes for Buildings in Smart Grids

DEFF Research Database (Denmark)

Kosek, Anna Magdalena; Costanzo, Giuseppe Tommaso; Bindner, Henrik W.

2013-01-01

The increasing share of distributed energy resources and renewable energy in power systems results in a highly variable and less controllable energy production. Therefore, in order to ensure stability and to reduce the infrastructure and operation cost of the power grid, flexible and controllable...... of the power sector in mind and thus can differ significantly in their architecture, their integration into the various markets, their integration into distribution network operation and several other aspects. This paper proposes a classification of load control policies for demand side management in smart...... buildings, based on external behavior: direct, indirect, transactional and autonomous control; internal operation: decision support system scope, control strategy, failure handling and architecture. This classification assists in providing an overview of the control schemes as well as different ways...

Ultrasonic Low-Friction Containment Plate for Thermal and Ultrasonic Stir Weld Processes

Science.gov (United States)

Graff, Karl; Short, Matt

2013-01-01

The thermal stir welding (TSW) process is finding applications in fabrication of space vehicles. In this process, workpieces to be joined by TSW are drawn, by heavy forces, between "containment plates," past the TSW tool that then causes joining of the separate plates. It is believed that the TSW process would be significantly improved by reducing the draw force, and that this could be achieved by reducing the friction forces between the workpieces and containment plates. Based on use of high-power ultrasonics in metal forming processes, where friction reduction in drawing dies has been achieved, it is believed that ultrasonic vibrations of the containment plates could achieve similar friction reduction in the TSW process. By applying ultrasonic vibrations to the containment plates in a longitudinal vibration mode, as well as by mounting and holding the containment plates in a specific manner such as to permit the plates to acoustically float, friction between the metal parts and the containment plates is greatly reduced, and so is the drawing force. The concept was to bring in the ultrasonics from the sides of the plates, permitting the ultrasonic hardware to be placed to the side, away from the equipment that contains the thermal stir tooling and that applies clamping forces to the plates. Tests demonstrated that one of the major objectives of applying ultrasonics to the thermal stir system, that of reducing draw force friction, should be achievable on a scaled-up system.

Demand-Side Financing--A Focus on Vouchers in Post-Compulsory Education and Training: Discussion Paper and Case Studies. CEDEFOP Dossier.

Science.gov (United States)

West, Anne; Sparkes, Jo; Balabanov, Todor

The use of demand-side financing mechanisms and vouchers for postcompulsory secondary-level education was examined through case studies of funding practices in the following countries: Austria; France; the United Kingdom; the United States; and Wallonia (the French community of Belgium). Different models of voucher use were identified in the…

Electricity deregulation, spot price patterns and demand-side management

International Nuclear Information System (INIS)

Li, Y.; Flynn, P.C.

2006-01-01

This paper examines extensive hourly or half-hourly power price data from 14 deregulated power markets. It analyzes average diurnal patterns, relationship to system load, volatility, and consistency over time. Diurnal patterns indicate the average price spread between off-peak and on-peak and weekend vs. weekday power consumption. Volatility is measured by price velocity: the average normalized hourly change in power price, calculated daily. The calculated price velocity is broken down into an expected component that arises from the diurnal pattern and an unexpected component that arises from unknown factors. The analysis reveals significant differences among markets, suggesting that demand-side management (DSM) of power consumption is far more difficult in some markets than in others. At one extreme, Spain, Britain and Scandinavia show consistent diurnal price patterns, a stable relationship between price and system load, and a low unexplained component of price volatility. A power consumer in these markets could form a reasonable expectation of a reward for DSM of elective power consumption. At the other extreme, two markets in Australia show erratic diurnal price patterns from year to year, low correlation between price and system load, and a high amount of unexpected price velocity. A power consumer in these markets would have far greater difficulty in realizing a benefit from DSM. Markets that experienced one period of very high prices without a clear external cause, such as California and Alberta, appear to have a significant longer-term erosion of public support for deregulation. (author)

Model Predictive Controller for Active Demand Side Management with PV Self-consumption in an Intelligent Building

DEFF Research Database (Denmark)

Zong, Yi; Mihet-Popa, Lucian; Kullmann, Daniel

2012-01-01

This paper presents a Model Predictive Controller (MPC) for electrical heaters’ predictive power consumption including maximizing the use of local generation (e.g. solar power) in an intelligent building. The MPC is based on dynamic power price and weather forecast, considering users’ comfort...... settings to meet an optimization objective such as minimum cost and minimum reference temperature error. It demonstrates that this MPC strategy can realize load shifting, and maximize the PV self-consumption in the residential sector. With this demand side control study, it is expected that MPC strategy...

Supply- and Demand-Side Factors Influencing Utilization of Infant and Young Child Feeding Counselling Services in Viet Nam.

Science.gov (United States)

Nguyen, Phuong H; Kim, Sunny S; Nguyen, Tuan T; Tran, Lan M; Hajeebhoy, Nemat; Frongillo, Edward A; Ruel, Marie T; Rawat, Rahul; Menon, Purnima

2016-01-01

Adequate utilization of services is critical to maximize the impact of counselling on infant and young child feeding (IYCF), but little is known about factors affecting utilization. Our study examined supply- and demand-side factors associated with the utilization of IYCF counselling services in Viet Nam. We used survey data from mothers with children Viet Nam, and may be relevant for increasing and sustaining use of nutrition services in similar contexts.

An Enhanced System Architecture for Optimized Demand Side Management in Smart Grid

Directory of Open Access Journals (Sweden)

Anzar Mahmood

2016-04-01

Full Text Available Demand Side Management (DSM through optimization of home energy consumption in the smart grid environment is now one of the well-known research areas. Appliance scheduling has been done through many different algorithms to reduce peak load and, consequently, the Peak to Average Ratio (PAR. This paper presents a Comprehensive Home Energy Management Architecture (CHEMA with integration of multiple appliance scheduling options and enhanced load categorization in a smart grid environment. The CHEMA model consists of six layers and has been modeled in Simulink with an embedded MATLAB code. A single Knapsack optimization technique is used for scheduling and four different cases of cost reduction are modeled at the second layer of CHEMA. Fault identification and electricity theft control have also been added in CHEMA. Furthermore, carbon footprint calculations have been incorporated in order to make the users aware of environmental concerns. Simulation results prove the effectiveness of the proposed model.

A Novel Prosumer-Based Energy Sharing and Management (PESM Approach for Cooperative Demand Side Management (DSM in Smart Grid

Directory of Open Access Journals (Sweden)

Sohail Razzaq

2016-10-01

Full Text Available Increasing population and modern lifestyle have raised energy demands globally. Demand Side Management (DSM is one important tool used to manage energy demands. It employs an advanced power infrastructure along with bi-directional information flow among utilities and users in order to achieve a balanced load curve and minimize demand-supply mismatch. Traditionally, this involves shifting the electricity demand from peak hours to other times of the day in an optimized manner. Multiple users equipped with renewable resources work in coordination with each other in order to achieve mutually beneficial energy management. This, in turn, has generated the concept of cooperative DSM. Such users, called prosumers, consume and produce energy using renewable resources (solar, wind etc.. Prosumers with surplus energy sell to the grid as well as to other consumers. In this paper, a novel Prosumer-based Energy Sharing and Management (PESM scheme for cooperative DSM has been proposed. A simulation model has been developed for testing the proposed method. Different variations of the proposed methodology have been experimented with different criteria. The results show that the proposed energy sharing scheme achieves DSM purposes in a useful manner.

Decomposition of toxicity emission changes on the demand and supply sides: empirical study of the US industrial sector

Science.gov (United States)

Fujii, Hidemichi; Okamoto, Shunsuke; Kagawa, Shigemi; Managi, Shunsuke

2017-12-01

This study investigated the changes in the toxicity of chemical emissions from the US industrial sector over the 1998-2009 period. Specifically, we employed a multiregional input-output analysis framework and integrated a supply-side index decomposition analysis (IDA) with a demand-side structural decomposition analysis (SDA) to clarify the main drivers of changes in the toxicity of production- and consumption-based chemical emissions. The results showed that toxic emissions from the US industrial sector decreased by 83% over the studied period because of pollution abatement efforts adopted by US industries. A variety of pollution abatement efforts were used by different industries, and cleaner production in the mining sector and the use of alternative materials in the manufacture of transportation equipment represented the most important efforts.

Visualized study on specific points on demand curves and flow patterns in a single-side heated narrow rectangular channel

International Nuclear Information System (INIS)

Wang Junfeng; Huang Yanping; Wang Yanlin

2011-01-01

Highlights: → Specific points on the demand curve and flow patterns are visually studied. → Bubbly, churn, and annular flows were observed. → Onset of flow instability and bubbly-churn transition occurs at the same time. → The evolution of specific points and flow pattern transitions were examined. - Abstract: A simultaneous visualization and measurement study on some specific points on demand curves, such as onset of nucleate boiling (ONB), onset of significant void (OSV), onset of flow instability (OFI), and two-phase flow patterns in a single-side heated narrow rectangular channel, having a width of 40 mm and a gap of 3 mm, was carried out. New experimental approaches were adopted to identify OSV and OFI in a narrow rectangular channel. Under experimental conditions, the ONB could be predicted well by the Sato and Matsumura model. The OSV model of Bowring can reasonably predict the OSV if the single-side heated condition is considered. The OFI was close to the saturated boiling point and could be described accurately by Kennedy's correlation. The two-phase flow patterns observed in this experiment could be classified into bubbly, churn, and annular flow. Slug flow was never observed. The OFI always occurred when the bubbles at the channel exit began to coalesce, which corresponded to the beginning of the bubbly-churn transition in flow patterns. Finally, the evolution of specific points and flow pattern transitions were examined in a single-side heated narrow rectangular channel.

Experimental and theoretical study of friction torque from radial ball bearings

Science.gov (United States)

Geonea, Ionut; Dumitru, Nicolae; Dumitru, Ilie

2017-10-01

In this paper it is presented a numerical simulation and an experimental study of total friction torque from radial ball bearings. For this purpose it is conceived a virtual CAD model of the experimental test bench for bearing friction torque measurement. The virtual model it is used for numerical simulation in Adams software, that allows dynamic study of multi-body systems and in particularly with facility Adams Machinery of dynamic behavior of machine parts. It is manufactured an experimental prototype of the test bench for radial ball bearings friction torque measurement. In order to measure the friction torque of the tested bearings it is used an equal resistance elastic beam element, with strain gauge transducer to measure bending deformations. The actuation electric motor of the bench has the shaft mounted on two bearings and the motor housing is fixed to the free side of the elastic beam, which is bended by a force proportional with the total friction torque. The beam elastic element with strain gauge transducer is calibrated in order to measure the force occurred. Experimental determination of the friction torque is made for several progressive radial loads. It is established the correlation from the friction torque and bearing radial load. The bench allows testing of several types and dimensions of radial bearings, in order to establish the bearing durability and of total friction torque.

Demand-side management project for Tenaga Nasional Berhad. Progress report No. 3. Volume 2. Export trade information

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-09-01

The objective of this work is identify and encompass those utility demand-side management (DSM) activities that influence customer electricity use to produce customer savings while favorably modifying the utility load. These activities can help utilities operate more efficiently and effectively in uncertain and competitive business environments. This work authorization will initiate the following: Provide descriptive information on the operating characteristics, applicability, specifications, costs, and benefits of DSM/end-use technologies; Characterize the marketing methods used to encourage customer acceptance of these technologies.

A Virtual Power Plant Architecture for the Demand-Side Management of Smart Prosumers

Directory of Open Access Journals (Sweden)

Marco Pasetti

2018-03-01

Full Text Available In this paper, we present a conceptual study on a Virtual Power Plant (VPP architecture for the optimal management of Distributed Energy Resources (DERs owned by prosumers participating in Demand-Side Management (DSM programs. Compared to classical VPP architectures, which aim to aggregate several DERs dispersed throughout the electrical grid, in the proposed VPP architecture the supervised physical domain is limited to single users, i.e., to single Points of Delivery (PODs of the distribution network. The VPP architecture is based on a service-oriented approach, where multiple agents cooperate to implement the optimal management of the prosumer’s assets, by also considering different forms of Demand Response (DR requests. The considered DR schemes range from Price-Based DRs to Event-Based DRs, covering both the normal operating functions and the emergency control requests applied in modern distribution networks. With respect to centralized approaches, in this study the control perspective is moved from the system level to the single prosumer’s level, who is allowed to independently provide flexible power profiles through the aggregation of multiple DERs. A generalized optimization model, formulated as a Mixed-Integer Linear Programming (MILP problem, is also introduced. Such a model is able to compute the optimal scheduling of a prosumer’s assets by considering both DR requests and end-users’ requirements in terms of comfort levels while minimizing the costs.

Friction-induced nanofabrication on monocrystalline silicon

International Nuclear Information System (INIS)

Yu Bingjun; Qian Linmao; Yu Jiaxin; Zhou Zhongrong; Dong Hanshan; Chen Yunfei

2009-01-01

Fabrication of nanostructures has become a major concern as the scaling of device dimensions continues. In this paper, a friction-induced nanofabrication method is proposed to fabricate protrusive nanostructures on silicon. Without applying any voltage, the nanofabrication is completed by sliding an AFM diamond tip on a sample surface under a given normal load. Nanostructured patterns, such as linear nanostructures, nanodots or nanowords, can be fabricated on the target surface. The height of these nanostructures increases rapidly at first and then levels off with the increasing normal load or number of scratching cycles. TEM analyses suggest that the friction-induced hillock is composed of silicon oxide, amorphous silicon and deformed silicon structures. Compared to the tribochemical reaction, the amorphization and crystal defects induced by the mechanical interaction may have played a dominating role in the formation of the hillocks. Similar to other proximal probe methods, the proposed method enables fabrication at specified locations and facilitates measuring the dimensions of nanostructures with high precision. It is highlighted that the fabrication can also be realized on electrical insulators or oxide surfaces, such as quartz and glass. Therefore, the friction-induced method points out a new route in fabricating nanostructures on demand.

Modeling Friction in Modelica with the Lund-Grenoble Friction Model

OpenAIRE

Aberger, Martin; Otter, Martin

2002-01-01

The properties of the Lund-Grenoble friction model are summarized and different types of friction elements - bearing friction, clutch, one-way clutch, are implemented in Modelica using this friction formulation. The dynamic properties of these components are determined in simulations and compared with the friction models available in the Modelica standard library. This includes also an automatic gearbox model where 6 friction elements are coupled dynamically.

A study on the frictional response of reptilian shed skin

International Nuclear Information System (INIS)

Abdel-Aal, H A; Vargiolu, R; Zahouani, H; Mansori, M El

2011-01-01

Deterministic surfaces are constructs of which profile, topography and textures are integral to the function of the system they enclose. They are designed to yield a predetermined tribological response. Developing such entities relies on controlling the structure of the rubbing interface so that, not only the surface is of optimized topography, but also is able to self-adjust its tribological behaviour according to the evolution of sliding conditions. In seeking inspirations for such designs, many engineers are turning toward the biological world to study the construction and behaviour of bio-analogues, and to probe the role surface topography assumes in conditioning of frictional response. That is how a bio-analogue can self-adjust its tribological response to adapt to habitat constraints. From a tribological point of view, Squamate Reptiles, offer diverse examples where surface texturing, submicron and nano-scale features, achieves frictional regulation. In this paper, we study the frictional response of shed skin obtained from a snake (Python regius). The study employed a specially designed tribo-acoustic probe capable of measuring the coefficient of friction and detecting the acoustical behavior of the skin in vivo. The results confirm the anisotropy of the frictional response of snakes. The coefficient of friction depends on the direction of sliding: the value in forward motion is lower than that in the backward direction. Diagonal and side winding motion induces a different value of the friction coefficient. We discuss the origin of such a phenomenon in relation to surface texturing and study the energy constraints, implied by anisotropic friction, on the motion of the reptile.

A study on the frictional response of reptilian shed skin

Energy Technology Data Exchange (ETDEWEB)

Abdel-Aal, H A [Arts et Metier ParisTech, Rue Saint Dominique BP 508, 51006 Chalons-en-Champagne (France); Vargiolu, R; Zahouani, H [Laboratoire de Tribology et Dynamique des Systemes, UMR CNRS 5513, ENI Saint Etienne - Ecole Centrale de Lyon -36 Avenue Guy de Collongue, 69131 Ecully cedex. France (France); Mansori, M El, E-mail: Hisham.abdel-aal@ensam.eu [Ecole Nationale Superieure d' Arts et Metiers, 2, cours des Arts et Metiers - 13617 Aix en Provence cedex 1 (France)

2011-08-19

Deterministic surfaces are constructs of which profile, topography and textures are integral to the function of the system they enclose. They are designed to yield a predetermined tribological response. Developing such entities relies on controlling the structure of the rubbing interface so that, not only the surface is of optimized topography, but also is able to self-adjust its tribological behaviour according to the evolution of sliding conditions. In seeking inspirations for such designs, many engineers are turning toward the biological world to study the construction and behaviour of bio-analogues, and to probe the role surface topography assumes in conditioning of frictional response. That is how a bio-analogue can self-adjust its tribological response to adapt to habitat constraints. From a tribological point of view, Squamate Reptiles, offer diverse examples where surface texturing, submicron and nano-scale features, achieves frictional regulation. In this paper, we study the frictional response of shed skin obtained from a snake (Python regius). The study employed a specially designed tribo-acoustic probe capable of measuring the coefficient of friction and detecting the acoustical behavior of the skin in vivo. The results confirm the anisotropy of the frictional response of snakes. The coefficient of friction depends on the direction of sliding: the value in forward motion is lower than that in the backward direction. Diagonal and side winding motion induces a different value of the friction coefficient. We discuss the origin of such a phenomenon in relation to surface texturing and study the energy constraints, implied by anisotropic friction, on the motion of the reptile.

Climate-related electricity demand-side management in oil-exporting countries--the case of the United Arab Emirates

International Nuclear Information System (INIS)

Al-Iriani, Mahmoud A.

2005-01-01

The oil crisis of the 1970s has increased the concern about the continuity of oil imports flow to major oil-importing developed countries. Numerous policy measures including electricity demand-side management (DSM) programs have been adopted in such countries. These measures aim at reducing the growing need for electricity power that increases the dependency on imported foreign oil and damages the environment. On the other hand, the perception that energy can be obtained at very low cost in oil-rich countries led to less attention being paid to the potential of DSM policies in these countries. This paper discusses such potential using the case of the United Arab Emirates (UAE). Since air conditioning is a major source of electric energy consumption, the relationship between climate conditions and electric energy consumption is considered. An electricity demand model is constructed using time series techniques. The fitted model seems to represent these relationships rather well. Forecasts for electricity consumption using the estimated model indicate that a small reduction in cooling degrees requirement might induce a significant reduction in electric energy demand. Hence, a DSM program is proposed with policy actions to include, among others, measures to reduce cooling degrees requirement

Grey-box Modelling of a Household Refrigeration Unit Using Time Series Data in Application to Demand Side Management

DEFF Research Database (Denmark)

Sossan, Fabrizio; Lakshmanan, Venkatachalam; Costanzo, Giuseppe Tommaso

2016-01-01

This paper describes the application of stochastic grey-box modeling to identify electrical power consumption-to-temperature models of a domestic freezer using experimental measurements. The models are formulated using stochastic differential equations (SDEs), estimated by maximum likelihood......) to shift the electricity consumption of a freezer in demand response experiments, thereby addressing the model selection problem also from the application point of view and showing in an experimental context the ability of MPC to exploit the freezer as a demand side resource (DSR)....... estimation (MLE), validated through the model residuals analysis and cross-validated to detect model over-fitting. A nonlinear model based on the reversed Carnot cycle is also presented and included in the modeling performance analysis. As an application of the models, we apply model predictive control (MPC...

Acoustics of friction

Science.gov (United States)

Akay, Adnan

2002-04-01

This article presents an overview of the acoustics of friction by covering friction sounds, friction-induced vibrations and waves in solids, and descriptions of other frictional phenomena related to acoustics. Friction, resulting from the sliding contact of solids, often gives rise to diverse forms of waves and oscillations within solids which frequently lead to radiation of sound to the surrounding media. Among the many everyday examples of friction sounds, violin music and brake noise in automobiles represent the two extremes in terms of the sounds they produce and the mechanisms by which they are generated. Of the multiple examples of friction sounds in nature, insect sounds are prominent. Friction also provides a means by which energy dissipation takes place at the interface of solids. Friction damping that develops between surfaces, such as joints and connections, in some cases requires only microscopic motion to dissipate energy. Modeling of friction-induced vibrations and friction damping in mechanical systems requires an accurate description of friction for which only approximations exist. While many of the components that contribute to friction can be modeled, computational requirements become prohibitive for their contemporaneous calculation. Furthermore, quantification of friction at the atomic scale still remains elusive. At the atomic scale, friction becomes a mechanism that converts the kinetic energy associated with the relative motion of surfaces to thermal energy. However, the description of the conversion to thermal energy represented by a disordered state of oscillations of atoms in a solid is still not well understood. At the macroscopic level, friction interacts with the vibrations and waves that it causes. Such interaction sets up a feedback between the friction force and waves at the surfaces, thereby making friction and surface motion interdependent. Such interdependence forms the basis for friction-induced motion as in the case of

Power System Transient Stability Improvement Using Demand Side Management in Competitive Electricity Markets

DEFF Research Database (Denmark)

Hu, Weihao; Wang, Chunqi; Chen, Zhe

2012-01-01

Since the hourly spot market price is available one day ahead in Denmark, the price could be transferred to the consumers and they may shift some of their loads from high price periods to the low price periods in order to save their energy costs. The optimal load response to an electricity price...... for demand side management generates different load profiles and may provide an opportunity to improve the transient stability of power systems with high wind power penetrations. In this paper, the idea of the power system transient stability improvement by using optimal load response to the electricity...... price is proposed. A 102-bus power system which represents a simplified model of the western Danish power system is chosen as the study case. Simulation results show that the optimal load response to electricity prices is an effective measure to improve the power system transient stability with high...

Smart grids and power systems efficiency: regulatory tools and demand-side management impacts

International Nuclear Information System (INIS)

Bergaentzle, Claire

2015-01-01

The physical architecture of electricity grids and the organizational structure of power systems implemented after the reforms have traditionally be achieved according to the characteristics of the transmission infrastructures and power mixes. However, the new challenges related to energy transition favor a greater participation of decentralized generation and final consumers to system exploitation and competitive markets. This latter participation is made possible thanks to recent innovations in the fields of communication and remote control technologies. Significant evolutions are expected in power industries that share common characteristics. First, these evolutions suppose massive capital investments to modernize and adapt current power distribution grids. Second, it is expected the activation of distribution grids and final consumers will unleash substantial unexploited economic efficiency gains as well as impose new constraints. Taking these simple facts as a starting point, the objective of the thesis is twofold. In the first place, we provide a theoretical analysis of the regulatory instruments that monitor the system operators' expenses. Relying on the literature, we aim at characterizing what regulatory tools and incitation are suitable for investing in smart grids technologies. Since it is necessary to compare theoretical formulation to facts, we use an empirical approach that allows us to designate key benefits pursued by the development of smart grids and to compare our theoretical results with practical regulatory applications. Our findings eventually allow us to formulate recommendations. In the second place, the thesis focuses on the impacts of demand-side management during peak periods. We structure our approach around two general observations. Large benefits should be generated in lowering substantially peak demand. However, such situation also creates losses of profit for generators. We provide an estimation of efficiency gains and revenue losses

Intra-articular fibroma of tendon sheath in a knee joint associated with iliotibial band friction syndrome

Energy Technology Data Exchange (ETDEWEB)

Ha, Dong Ho; Choi, Sun Seob; Kim, Soo Jin; Lih, Wang [Dong-A University Medical Center, Busan (Korea, Republic of)

2015-02-15

Iliotibial band (ITB) friction syndrome is a common overuse injury typically seen in the active athlete population. A nodular lesion on the inner side of the ITB as an etiology or an accompanying lesion from friction syndrome has been rarely reported. A 45-year-old male presented with recurrent pain and a movable nodule at the lateral joint area, diagnosed as ITB friction syndrome. The nodule was confirmed as a rare intra-articular fibroma of the tendon sheath (FTS) on the basis of histopathologic findings. We describe the MRI findings, arthroscopic and pathologic features, in this case of intra-articular FTS presenting with ITB friction syndrome.

Intra-articular fibroma of tendon sheath in a knee joint associated with iliotibial band friction syndrome

International Nuclear Information System (INIS)

Ha, Dong Ho; Choi, Sun Seob; Kim, Soo Jin; Lih, Wang

2015-01-01

Iliotibial band (ITB) friction syndrome is a common overuse injury typically seen in the active athlete population. A nodular lesion on the inner side of the ITB as an etiology or an accompanying lesion from friction syndrome has been rarely reported. A 45-year-old male presented with recurrent pain and a movable nodule at the lateral joint area, diagnosed as ITB friction syndrome. The nodule was confirmed as a rare intra-articular fibroma of the tendon sheath (FTS) on the basis of histopathologic findings. We describe the MRI findings, arthroscopic and pathologic features, in this case of intra-articular FTS presenting with ITB friction syndrome.

Microhardness and Strain Field Characterization of Self-Reacting Friction Stir and Plug Welds of Dissimilar Aluminum Alloys

Science.gov (United States)

Horton, Karla Renee

2011-01-01

Friction stir welding (FSW) is a solid state welding process with potential advantages for aerospace and automotive industries dealing with light alloys. Self-reacting friction stir welding (SR-FSW) is one variation of the FSW process being developed at the National Aeronautics and Space Administration (NASA) for use in the fabrication of propellant tanks. Friction plug welding is used to seal the exit hole that remains in a circumferential SR-FSW. This work reports on material properties and strain patterns developed in a SR-FSW with a friction plug weld. Specifically, this study examines the behavior of a SR-FSW formed between an AA 2014-T6 plate on the advancing side and an AA 2219-T87 plate on the retreating side and a SR-FSW (AA 2014-T6 to AA 2219-T87) with a 2219-T87 plug weld. This study presents the results of a characterization of the micro-hardness, joint strength, and strain field characterization of SR-FSW and FPW joints tested at room temperature and cryogenic temperatures.

A Physics-Based Rock Friction Constitutive Law: Steady State Friction

Science.gov (United States)

Aharonov, Einat; Scholz, Christopher H.

2018-02-01

Experiments measuring friction over a wide range of sliding velocities find that the value of the friction coefficient varies widely: friction is high and behaves according to the rate and state constitutive law during slow sliding, yet markedly weakens as the sliding velocity approaches seismic slip speeds. We introduce a physics-based theory to explain this behavior. Using conventional microphysics of creep, we calculate the velocity and temperature dependence of contact stresses during sliding, including the thermal effects of shear heating. Contacts are assumed to reach a coupled thermal and mechanical steady state, and friction is calculated for steady sliding. Results from theory provide good quantitative agreement with reported experimental results for quartz and granite friction over 11 orders of magnitude in velocity. The new model elucidates the physics of friction and predicts the connection between friction laws to independently determined material parameters. It predicts four frictional regimes as function of slip rate: at slow velocity friction is either velocity strengthening or weakening, depending on material parameters, and follows the rate and state friction law. Differences between surface and volume activation energies are the main control on velocity dependence. At intermediate velocity, for some material parameters, a distinct velocity strengthening regime emerges. At fast sliding, shear heating produces thermal softening of friction. At the fastest sliding, melting causes further weakening. This theory, with its four frictional regimes, fits well previously published experimental results under low temperature and normal stress.

Uncertainty Analysis for Oil-Film Interferometry Skin-Friction Measurement Techniques

Science.gov (United States)

Naughton, Jonathan W.; Brown, James L.; Merriam, Marshal (Technical Monitor)

1996-01-01

Over the past 20 years, the use of oil-film interferometry to measure the skin friction coefficient (C(sub f) = tau/q where tau is the surface shear stress and q is the dynamic pressure) has increased. Different forms of this oil-film technique with various levels of accuracy and ease of use have been successfully applied in a wide range of flows. The method's popularity is growing due to its relative ease of implementation and minimal intrusiveness as well as an increased demand for C(sub f) measurements. Nonetheless, the accuracy of these methods has not been rigorously addressed to date. Most researchers have simply shown that the skin-friction measurements made using these techniques compare favorably with other measurements and theory, most of which are only accurate to within 5-20%. The use of skin-friction data in the design of commercial aircraft, whose drag at cruise is 50% skin-friction drag, and in the validation of computational fluid dynamics programs warrants better uncertainty estimates. Additional information is contained in the original extended abstract.

Effects of friction on forced two-dimensional Navier-Stokes turbulence.

Science.gov (United States)

Blackbourn, Luke A K; Tran, Chuong V

2011-10-01

Large-scale dissipation mechanisms have been routinely employed in numerical simulations of two-dimensional turbulence to absorb energy at large scales, presumably mimicking the quasisteady picture of Kraichnan in an unbounded fluid. Here, "side effects" of such a mechanism--mechanical friction--on the small-scale dynamics of forced two-dimensional Navier-Stokes turbulence are elaborated by both theoretical and numerical analysis. Given a positive friction coefficient α, viscous dissipation of enstrophy has been known to vanish in the inviscid limit ν→0. This effectively renders the scale-neutral friction the only mechanism responsible for enstrophy dissipation in that limit. The resulting dynamical picture is that the classical enstrophy inertial range becomes a dissipation range in which the dissipation of enstrophy by friction mainly occurs. For each α>0, there exists a critical viscosity ν(c), which depends on physical parameters, separating the regimes of predominant viscous and frictional dissipation of enstrophy. It is found that ν(c)=[η'(1/3)/(Ck(f)(2))]exp[-η'(1/3)/(Cα)], where η' is half the enstrophy injection rate, k(f) is the forcing wave number, and C is a nondimensional constant (the Kraichnan-Batchelor constant). The present results have important theoretical and practical implications. Apparently, mechanical friction is a poor choice in numerical attempts to address fundamental issues concerning the direct enstrophy transfer in two-dimensional Navier-Stokes turbulence. Furthermore, as relatively strong friction naturally occurs on the surfaces and at lateral boundaries of experimental fluids as well as at the interfaces of shallow layers in geophysical fluid models, the frictional effects discussed in this study are crucial in understanding the dynamics of these systems.

Nonequilibrium Molecular Simulations of New Ionic Lubricants at Metallic Surfaces: Prediction of the Friction.

Science.gov (United States)

Mendonça, Ana C F; Pádua, Agílio A H; Malfreyt, Patrice

2013-03-12

We report nonequilibrium molecular dynamics of ionic liquids interacting with metallic surfaces. A specific set of interaction parameters for ionic liquids composed of alkylammonium cations and alkylsulfonate anions with an iron surface, which has been previously developed (J. Chem. Theory Comput.2012, 8, 3348) is used here. We develop a procedure for a quantitative prediction of the friction coefficient at different loads and shear rates. The simulated friction coefficient agrees very well with the available experimental ones. The dependence of friction on the load, shear velocity, surface topology, and length of alkyl side chains in the ionic liquid is also investigated. The changes in the frictional forces are explained in terms of the specific arrangements and orientations of groups forming the ionic liquid at the vicinity of the surface.

Friction stir spot welding of dissimilar aluminium alloys

International Nuclear Information System (INIS)

Bozkurt, Yahya

2016-01-01

Friction stir spot welding (FSSW) has been proposed as an effective technology to spot weld the so-called “difficult to be welded” metal alloys such as thin sheets aluminum alloys and dissimilar materials. FSSW is derived from friction stir welding technology, its principle benefit being low cost joining, lower welding temperature and shorter welding time than conventional welding methods. In this study, dissimilar AlMg 3 and AlCu 4 Mg 1 aluminium alloy plates were FSSWed by offsetting the low strength sheet on upper side of the weld. The effects of tool rotation speed on the microstructure, lap shear fracture load (LSFL), microhardness and fracture features of the weld are investigated by constant welding parameters. The maximum LSFL was obtained by increasing the tool rotational speed. However, the joints exhibited pull-out nugget fracture mode under lap shear tensile testing conditions. The largest completely bonded zone was observed as 5.86 mm which was narrower at the opposite position of the joint. Key words: friction stir spot welding, aluminium alloys, mechanical properties, dissimilar joint, welding parameters

Multicriteria evaluation of demand side management (DSM) implementation strategies in the Indian power sector

Energy Technology Data Exchange (ETDEWEB)

Vashishtha, Sanjay [Centre for Renewable Energy and Environmental Development (CREED), BITS, Pilani, Rajasthan 333031 (India); Ramachandran, M. [BITS Pilani Dubai Centre, Dubai (United Arab Emirates)

2006-09-15

In recent years, demand side management (DSM) has emerged as an efficient utility planning strategy for reducing capacity shortages and improving system load factors. The Indian government is adopting various policies to implement DSM programs. DSM implementation involves a variety of interests with conflicting objectives, and a range of possible implementation strategies with varying implications for effectiveness, cost, feasibility, efficiency and stakeholder acceptance. This necessitates a critical comparison of the strategies to determine a preferred strategy or combination of strategies from each specific stakeholder's point of view. The present study evaluates DSM implementation strategies from a multiobjective perspective using the Analytic Hierarchy Process (AHP). Eight strategies and six criteria were considered. Forty utility, regulator, and consumer stakeholders were surveyed. The most highly ranked strategies involved creating dedicated funds and providing technical support to end users for effective implementation of DSM. (author)

Demand side management at Enbridge and best practices in Canada

Energy Technology Data Exchange (ETDEWEB)

Hunt, K.; Griffin, B. [Enbridge Gas Distribution, Toronto, ON (Canada)

2004-07-01

In 1994, the Ontario Energy Board required that gas utilities implement DSM programs for all customers. Enbridge began delivering demand side management (DSM) programs in 1995. DSM is now fully integrated with marketing. DSM programs are delivered across the residential, commercial, industrial, and multi-residential sectors. In 1997, Enbridge introduced the Steam Saver Program for customers who own mid-sized and large steam boilers. The program is now saving customers over 41 million cubic metres of gas per year, representing over $10 million annually. Steam boiler plants burn 30 per cent of all fuel in Ontario. They include natural gas, oil, wood or coal. This paper included a table listing the annual fuel consumption and cost for 1,200 boiler plants in Ontario. The Steam Saver Program identified steam efficiency projects in the customer's plant, provided a business case for the customer and provided technical and financial help to implement the project. The average financial payback on steam efficiency projects is 1.7 years. This paper also described Enbridge's Natural Gas Construction Heater Program for new residential construction markets. The program promotes the benefits of natural gas construction heaters as an alternative to propane salamanders for curing concrete walls in basements, drywall drying, and thawing soil for basement floors before pouring concrete. The natural gas construction heaters are also more suitable for heating the home before a central furnace system is activated. 3 tabs., 6 figs.

Potential of Demand Side Management to Reduce Carbon Dioxide Emissions Associated with the Operation of Heat Pumps

Directory of Open Access Journals (Sweden)

Samuel J. G. Cooper

2013-06-01

Full Text Available This work considers the potential reduction in the carbon dioxide emissions associated with the operation of Air Source Heat Pump which could be achieved by using demand side management. In order to achieve significant reductions in carbon dioxide emissions, it is widely envisioned that electrification of the heating sector will need to be combined with decarbonisation of the electrical supply. By influencing the times at when electric heat pumps operate such that they coincide more with electricity generation which has a low marginal carbon emissions factor, it has been suggested that these emissions could be reduced further. In order to investigate this possibility, models of the UK electrical grid based on scenarios for 2020 to 2050 have been combined with a dynamic model of an air source heat pump unit and thermal models of a population of dwellings. The performance and carbon dioxide emissions associated with the heat pumps are compared both with and without demand side management interventions intended to give preference to operation when the marginal emissions factor of the electricity being generated is low. It is found that these interventions are unlikely to be effective at achieving further reductions in emissions. A reduction of around 3% was observed in scenarios based around 2035 but in other scenarios the reduction was insignificant. In the scenarios with high wind generation (2050, the DSM scheme considered here tends to improve thermal comfort (with minimal increases in emissions rather than achieving a decrease in emissions. The reasons for this are discussed and further recommendations are made.

Comparative Research on Characteristics of the Isolation Systems with Dry Friction Damping and with Vicious Damping under Base Excitation

Science.gov (United States)

Hou, Junfang; jing, Min; Zhang, Weihua; Lu, Yahui; He, Haiwen

2017-12-01

As for the isolation problem of electronic equipments on vehicle, the vibration response characteristics of dry friction damping isolation system under base displacement excitation was analyzed in theory by harmonic balance method, and the displacement response was compared between the isolation systems with dry friction damping and vicious damping separately. The results show that the isolation system with small dry friction damping can’t meet the demands of displacement reduction close to the natural frequency, and it can realize full-frequency vibration isolation by improving dry friction damping when the lock frequency passes beyond the resonance frequency band. The results imply that the damping mechanism of dry friction isolator can’t be described only by dry friction damping, and the composite damping with dry friction and vicious damping is more appropriate.

Austria's Energy Perspectives - It's the Demand Side, Stupid

International Nuclear Information System (INIS)

Lechner, H.

2009-01-01

During the last decade Austria made remarkable progress in developing renewable energy sources. But at the same time energy demand has steadily increased so that the share of renewables in the energy mix has remained more or less stable over the years. Rising energy demand and import dependence is also forecast in a business-as-usual scenario for the future. If Austria is to fulfill the EU obligatory target to increase the share of renewables up to 34% in 2020 (recently 25%) and to move on a sustainable, low-carbon track it will have to decrease energy consumption or at least stabilise it at the level of 2005. This requires considerable efforts to boost energy efficiency, especially in the building and transport sector.(author).

From demand side management (DSM) to energy efficiency services: A Finnish case study

International Nuclear Information System (INIS)

Apajalahti, Eeva-Lotta; Lovio, Raimo; Heiskanen, Eva

2015-01-01

Energy conservation is expected to contribute significantly to climate change mitigation and energy security. Traditionally, energy companies have had strong role in providing Demand Side Management (DSM) measures. However, after energy market liberalization in Europe, energy companies' DSM activities declined. In response, the EU issued Directive (2006/32/EC) on energy end-use efficiency and energy services (ESD) to motivate energy companies to promote energy efficiency and conservation, closely followed by Directive (2012/27/EU) on energy efficiency (EED), requiring the setting up energy efficiency obligation schemes. Despite strong political and economic motivation, energy companies struggle to develop energy efficiency services in liberalised energy markets due to conflicting institutional demands, which arise from contradicting policy requirements and customer relations. The main challenges in developing new innovative energy efficiency services, evidenced by an in-depth case study, were (1) the unbundling of energy company operations, which makes it difficult to develop services when the contribution of several business units is required and (2) the distrust among energy end-users, which renders the business logic of energy saving contract models self-contradictory. On the basis of the research, avenues out of these dilemmas are suggested. -- Highlights: •Energy companies struggle to become energy service provides •We explore the development of new energy saving business solutions •Dispersed organisational structure leaves energy saving business as isolated function •Strong consumer scepticism towards energy companies as providers of energy saving •More emphasis on the changing company-customer relationship is needed

Physically representative atomistic modeling of atomic-scale friction

Science.gov (United States)

Dong, Yalin

Nanotribology is a research field to study friction, adhesion, wear and lubrication occurred between two sliding interfaces at nano scale. This study is motivated by the demanding need of miniaturization mechanical components in Micro Electro Mechanical Systems (MEMS), improvement of durability in magnetic storage system, and other industrial applications. Overcoming tribological failure and finding ways to control friction at small scale have become keys to commercialize MEMS with sliding components as well as to stimulate the technological innovation associated with the development of MEMS. In addition to the industrial applications, such research is also scientifically fascinating because it opens a door to understand macroscopic friction from the most bottom atomic level, and therefore serves as a bridge between science and engineering. This thesis focuses on solid/solid atomic friction and its associated energy dissipation through theoretical analysis, atomistic simulation, transition state theory, and close collaboration with experimentalists. Reduced-order models have many advantages for its simplification and capacity to simulating long-time event. We will apply Prandtl-Tomlinson models and their extensions to interpret dry atomic-scale friction. We begin with the fundamental equations and build on them step-by-step from the simple quasistatic one-spring, one-mass model for predicting transitions between friction regimes to the two-dimensional and multi-atom models for describing the effect of contact area. Theoretical analysis, numerical implementation, and predicted physical phenomena are all discussed. In the process, we demonstrate the significant potential for this approach to yield new fundamental understanding of atomic-scale friction. Atomistic modeling can never be overemphasized in the investigation of atomic friction, in which each single atom could play a significant role, but is hard to be captured experimentally. In atomic friction, the

Influence of the Type of Marking and the Number of Players on Physiological and Physical Demands During Sided Games in Soccer

Directory of Open Access Journals (Sweden)

Casamichana David

2015-09-01

Full Text Available The aim of this research was to examine the influence of two variables, the type of marking (with or without man-marking and the number of players per team (3, 6, or 9 on the physical and physiological demands of sided games in soccer. Eighteen amateur players were monitored with GPS and heart rate devices. The following variables were analyzed: a maximum heart rate, a mean heart rate, time spent in each intensity range, total distance covered and distance covered in different speed ranges, a player load, maximum speed reached, and a work:rest ratio. The results showed that the type of marking influenced the physical demands of players, with greater total distance, a player load and a work:rest ratio when man-marking was used in the 3 vs. 3 (737 m, 95 Arbitrary Units (AU and 3.4 AU, respectively and 6 vs. 6 (783 m, 95 AU and 5.3 AU, respectively games (p<0.05. The number of players also had an effect on physiological intensity, with more time being spent at the <80%HRmax during the 9 vs. 9 and 6 vs. 6 games (more than 30% compared with the 3 vs. 3 format (less than 15% (p<0.05. These findings could help coaches to understand how the modification of different variables in sided games influences the physical and physiological demands of players.

Differences in strength and speed demands between 4v4 and 8v8 small-sided football games

DEFF Research Database (Denmark)

Rebelo, António Natal Campos; Silva, Pedro; Rago, Vincenzo

2016-01-01

The aims of this study were (i) to characterise the acceleration demands of two different formats of small-sided game (SSG), i.e., 4v4 + goalkeepers (4v4 + GK) and 8v8 + goalkeepers (8v8 + GK); (ii) to analyse the correlation between performance in power-based tests and acceleration-based physica...... to repetitions and fatigue development of muscle power-based actions than 8v8 + GK. It may therefore be logical to use the former type of SSG to target development of power-related football actions....

PEBBLES Simulation of Static Friction and New Static Friction Benchmark

International Nuclear Information System (INIS)

Cogliati, Joshua J.; Ougouag, Abderrafi M.

2010-01-01

Pebble bed reactors contain large numbers of spherical fuel elements arranged randomly. Determining the motion and location of these fuel elements is required for calculating certain parameters of pebble bed reactor operation. This paper documents the PEBBLES static friction model. This model uses a three dimensional differential static friction approximation extended from the two dimensional Cundall and Strack model. The derivation of determining the rotational transformation of pebble to pebble static friction force is provided. A new implementation for a differential rotation method for pebble to container static friction force has been created. Previous published methods are insufficient for pebble bed reactor geometries. A new analytical static friction benchmark is documented that can be used to verify key static friction simulation parameters. This benchmark is based on determining the exact pebble to pebble and pebble to container static friction coefficients required to maintain a stable five sphere pyramid.

Can demand-side policies stop the tobacco industry's damage? Lessons from Turkey.

Science.gov (United States)

Gultekin-Karakas, Derya

2015-01-01

Trade and investment liberalisation in the post-1980 period allowed the penetration of transnational tobacco companies into the Turkish market. State control over the market was gradually removed and tobacco farming, manufacturing, trade and consumption were reshaped in line with the needs of transnational tobacco companies. The resultant increase in product proliferation and aggressive marketing strategies led to a dramatic rise in cigarette consumption in the 1990s, making Turkey a market with one of the sharpest consumption increases in the world. While Turkey implemented demand-side tobacco control policies to reduce consumption after 1996, it continued to stimulate manufacturing and trade in a conflicting way. The Turkish case verifies that the liberalisation process facilitated by the state under the auspices of international institutions conflicts with tobacco control. Liberalisation paves the way for market expansions of transnational tobacco companies that resist tobacco control in their drive for profit. Current global tobacco control policies, with no interest in controlling manufacturing, have limited effect on consumption. The Turkish case indicates the necessity of establishing public control over tobacco manufacturing and trade from a public health perspective.

Trial manufacture of rotary friction tester and frictional force measurement of metals

CERN Document Server

Abe, T; Kanari, M; Tanzawa, S

2002-01-01

In the plasma confinement type fusion reactor, in-vessel structures such as a blanket module slide at the joints each other when plasma disruption occurs, and then frictional heat is generated there. Therefore, for the selection of material and the use as the design data, it is important to understand the frictional characteristics of metals and ceramic films in the vacuum. In the present study, we have manufactured a prototype of rotary friction tester and examined the performances of the tester. The frictional characteristics of metals in the room air was measured using the friction tester, and the results obtained are as follows. A drifting friction force for a constant time and a friction force during the idling were 98 mN and 225 mN, respectively. These values were sufficiently small as compared to pressing load (9.8 - 57.8 N) used in the friction test. In a friction force measurement of stainless steel, dynamic friction force obeyed Amontons' law which indicated that dynamic friction force is not depend...

CISM-IUTAM Summer School on Friction and Instabilities

CERN Document Server

Raous, M; Friction and Instabilities

2000-01-01

The book addresses instability and bifurcation phenomena in frictional contact problems. The treatment of this subject has its roots in previous studies of instability and bifurcation in elastic, thermoelastic or elastic-plastic bodies, and in previous mathematical, mechanical and computational studies of unilateral problems. The salient feature of this book is to put together and develop concepts and tools for stability and bifurcation studies in mechanics, taking into account the inherent non-smoothness and non-associativity (non-symmetry) of unilateral frictional contact laws. The mechanical foundations, the mathematical theory and the computational algorithms for such studies are developed along six chapters written by the lecturers of a CISM course. Those concepts and tools are illustrated not only with enlightening academic examples but also with some demanding industrial applications, related, namely, to the automotive industry.

Stabilization of Gob-Side Entry with an Artificial Side for Sustaining Mining Work

Directory of Open Access Journals (Sweden)

Hong-sheng Wang

2016-07-01

Full Text Available A concrete artificial side (AS is introduced to stabilize a gob-side entry (GSE. To evaluate the stability of the AS, a uniaxial compression failure experiment was conducted with large and small-scale specimens. The distribution characteristics of the shear stress were obtained from a numerical simulation. Based on the failure characteristics and the variation of the shear stress, a failure criterion was determined and implemented in the strengthening method for the artificial side. In an experimental test, the distribution pattern of the maximum shear stress showed an X shape, which contributed to the failure shape of the specimen. The shear stress distribution and failure shape are induced by a combination of two sets of shear stresses, which implies that failure of the AS follows the twin shear strength theory. The use of anchor bolts, bolts, and anchor bars enhances the shear strength of the artificial side. When this side is stable, the components can constrain the lateral deformation as well as improve the internal friction angle and cohesion. When the AS is damaged, the components prevent the sliding of broken blocks along the shear failure plane and improve the residual strength of the artificial side. When reinforced with an anchor bar, the AS is still stable even after mining operations for three years.

Communications technologies for demand side management, DSM, and European utility communications architecture, EurUCA

Energy Technology Data Exchange (ETDEWEB)

Kaerkkaeinen, S.; Kekkonen, V. [VTT Energy, Espoo (Finland); Rissanen, P. [Tietosavo Oy (Finland)

1996-12-31

In this project the main target is to develop and assess methods for DSM (Demand Side Management) and distribution automation planning from the utility`s point of view. The final goal is to integrate these methods for the strategic planning of electric utilities. In practice the project is divided into four main parts: The development and assessment of DSM/IRP planning methods and cost/benefit analysis as a part of international co-operation (IEA DSM Agreement: Annex IV, European Cost/Benefit analysis of DSM, EUBC, and Finnish SAVE-project started in 1995 in co-operation with SRC International and six electric utilities in Finland); Development of PC-based DSM planning and assessment tools at VTT; Development of a decision support system of distribution network planning including DSM options at Tietosavo Oy and Integration of DSM planning and network planning tools in co-operation with VTT Energy and Tietosavo Oy

Communications technologies for demand side management, DSM, and European utility communications architecture, EurUCA

Energy Technology Data Exchange (ETDEWEB)

Kaerkkaeinen, S; Kekkonen, V [VTT Energy, Espoo (Finland); Rissanen, P [Tietosavo Oy (Finland)

1997-12-31

In this project the main target is to develop and assess methods for DSM (Demand Side Management) and distribution automation planning from the utility`s point of view. The final goal is to integrate these methods for the strategic planning of electric utilities. In practice the project is divided into four main parts: The development and assessment of DSM/IRP planning methods and cost/benefit analysis as a part of international co-operation (IEA DSM Agreement: Annex IV, European Cost/Benefit analysis of DSM, EUBC, and Finnish SAVE-project started in 1995 in co-operation with SRC International and six electric utilities in Finland); Development of PC-based DSM planning and assessment tools at VTT; Development of a decision support system of distribution network planning including DSM options at Tietosavo Oy and Integration of DSM planning and network planning tools in co-operation with VTT Energy and Tietosavo Oy

3-dimensional numerical analysis of friction stir welding of copper and aluminum

Energy Technology Data Exchange (ETDEWEB)

Aleagha, M. E. Aalami; Hadi, Behzad; Shahbazi, Mohammad Ali [Dept. of Mechanical Engineering, School of Engineering, Razi University, Kermanshah (Iran, Islamic Republic of)

2016-08-15

A time dependent Eulerian thermal/material flow model of friction stir welding was developed and applied to the dissimilar joining of pure copper and aluminum 1050-H16 alloy to investigate the maximum penetration of base metals. Thermal and material flow analysis was done with the assumed velocity field in the stir zone and considering a thermal source of energy obtained from the both Coulomb type of friction and the loss of shear stress in a non-Newtonian viscous behavior of metal flow. The developed model was used to estimate temperature gradient and penetration of material under three different conditions of tool offset and compared with the experimental results. The model shows that the penetration of the base metals is closely related to tool offset. In all of the cases, the metal fixed in the advancing side is copper. Nevertheless, when considering tool offset in the copper side and also when considering tool offset in the aluminum side, penetrating metals are copper and aluminum, respectively. Also, the model shows that the maximum temperature achieved in the base metals significantly depends on the tool offset.

Demonstrating a small utility approach to demand-side program implementation

International Nuclear Information System (INIS)

1991-01-01

The US DOE awarded a grant to the Burlington Electric Department (B.E.D.) to test a demand-side management (DSM) demonstration program designed to quickly save a significant amount of power with little disruption to the utility's customers or its normal operations. B.E.D. is a small municipal utility located in northern Vermont, with a lengthy history of successful DSM involvement. In our grant application, we proposed to develop a replicable program and approach to DSM that might be useful to other small utilities and to write a report to enable such replication. We believe that this DSM program and/or individual program components are replicable. This report is designed to allow other utilities interested in DSM to replicate this program or specific program design features to meet their DSM goals. We also wanted to use the opportunity of this grant to test the waters of residential heating fuel-switching. We hoped to test the application of one fuel-switching technology, and to benefit from the lessons learned in developing a full-scale DSM program for this end- use. To this end the pilot effort has been very successful. In the pilot pressure we installed direct-vent gas fired space heaters sized as supplemental heating units in 44 residences heated solely by electric resistance heat. We installed the gas space heating units at no cost to the owners or residents. We surveyed participating customers. The results of those surveys are included in this report and preliminary estimates of winter peak capacity load reductions are also noted in this report

Demonstrating a small utility approach to demand-side program implementation

Energy Technology Data Exchange (ETDEWEB)

1991-10-01

The US DOE awarded a grant to the Burlington Electric Department (B.E.D.) to test a demand-side management (DSM) demonstration program designed to quickly save a significant amount of power with little disruption to the utility's customers or its normal operations. B.E.D. is a small municipal utility located in northern Vermont, with a lengthy history of successful DSM involvement. In our grant application, we proposed to develop a replicable program and approach to DSM that might be useful to other small utilities and to write a report to enable such replication. We believe that this DSM program and/or individual program components are replicable. This report is designed to allow other utilities interested in DSM to replicate this program or specific program design features to meet their DSM goals. We also wanted to use the opportunity of this grant to test the waters of residential heating fuel-switching. We hoped to test the application of one fuel-switching technology, and to benefit from the lessons learned in developing a full-scale DSM program for this end- use. To this end the pilot effort has been very successful. In the pilot pressure we installed direct-vent gas fired space heaters sized as supplemental heating units in 44 residences heated solely by electric resistance heat. We installed the gas space heating units at no cost to the owners or residents. We surveyed participating customers. The results of those surveys are included in this report and preliminary estimates of winter peak capacity load reductions are also noted in this report.

Exploring Community-Oriented Approaches in Demand Side Management Projects in Europe

Directory of Open Access Journals (Sweden)

Anna Mengolini

2016-12-01

Full Text Available This paper seeks to investigate if the theoretical and political trends towards a more collective dimension of energy use are reflected in the design and development of demand side management (DSM pilot projects in Europe. Specifically, the paper analyses DSM projects in the database of the Joint Research Centre (JRC of the European Commission to capture signs of a new attention towards the wider context in which consumers live and towards the social dimension associated with energy consumption. To this end, the paper investigates the projects’ scope (in terms of project’s partners, end-use sectors and targeted services as well as the consumer engagement strategies that projects use. These elements reflect the projects’ consideration for the socio-economic dimension of the community where the pilots take place and their inclination to build on community dynamics. The analysis shows that DSM projects in the EU are increasingly being designed and developed with a collegial approach to energy consumption in mind, although an integrated approach is still missing. In addition, research is still needed to link the use of this innovative approach to project results. A closer look at the developments and results of these projects can help to identify what works and what doesn’t in real life experiences, thus supporting effective policy making at the EU and national level.

The distinct element analysis for swelling pressure test of bentonite. Discussion on the effects of wall friction force and aspect ratio of specimen

International Nuclear Information System (INIS)

Shimizu, Hiroyuki; Kikuchi, Hirohito; Fujita, Tomoo; Tanai, Kenji

2011-10-01

For geological isolation systems for radioactive waste, bentonite based material is assumed to be used as a buffer material. The swelling characteristics of the bentonite based material are expected to fill up the void space around the radioactive wastes by swelling. In general, swelling characteristics and properties of bentonite are evaluated by the laboratory tests. However, due to the lack of standardization of testing method for bentonite, the accuracy and reproducibility of the testing results are not sufficiently proved. In this study, bentonite swelling pressure test were simulated by newly developed Distinct Element Method (DEM) code, and the effects of wall friction force and aspect ratio of bentonite specimen were discussed. As a result, the followings were found. In the beginning of the swelling pressure test, since swelling occurs only around the fluid injection side of the specimen, wall friction force acts only in the swelling area and the specimen moves to opposite side from fluid injection side. However, when the entire specimen started swelling, displacement of the specimen prevented by the wall friction force, and the specimen is pressed against the pressure measurement side. Then, the swelling pressure measured on the pressure measurement side increases. Such displacement in the specimen is significantly affected by the decreasing of mechanical properties and the difference of saturation in the bentonite specimen during the fluid infiltration. Moreover, when the aspect ratio of the specimen is large, the displacement of the particle in the specimen becomes large and the area on which the wall frictional force acts is also large. Therefore, measured swelling pressure increases more greatly as the aspect ratio of the specimen increases. To contributes to the standardization of laboratory test methods for bentonite, these effects of wall friction force revealed by the DEM simulation should be verified through laboratory experiments. (author)

On the importance of the supply side in demand-side management

International Nuclear Information System (INIS)

Fischer, Carolyn

2005-01-01

We discuss how the structure of market supply affects the evaluation of policies to promote energy efficiency in household appliances. If competitive markets offer the levels that consumers demand, product standards inefficiently restrict choice. If suppliers price discriminate, minimum standards can restrict the inefficient use of energy intensity to segment consumers. We also compare the effects of average intensity standards, energy prices and innovation, and consider what the different behavioral predictions imply for empirical studies of energy efficiency. Good policymaking requires knowing not only how consumers value energy efficiency in their decision-making, but also how producers respond to those values

On the importance of the supply side in demand-side management

International Nuclear Information System (INIS)

Fischer, C.

2005-01-01

We discuss how the structure of market supply affects the evaluation of policies to promote energy efficiency in household appliances. If competitive markets offer the levels that consumers demand, product standards inefficiently restrict choice. If suppliers price discriminate, minimum standards can restrict the inefficient use of energy intensity to segment consumers. We also compare the effects of average intensity standards, energy prices and innovation, and consider what the different behavioral predictions imply for empirical studies of energy efficiency. Good policy making requires knowing not only how consumers value energy efficiency in their decision-making, but also how producers respond to those values. (author)

Demand response in energy markets

International Nuclear Information System (INIS)

Skytte, K.; Birk Mortensen, J.

2004-11-01

Improving the ability of energy demand to respond to wholesale prices during critical periods of the spot market can reduce the total costs of reliably meeting demand, and the level and volatility of the prices. This fact has lead to a growing interest in the short-run demand response. There has especially been a growing interest in the electricity market where peak-load periods with high spot prices and occasional local blackouts have recently been seen. Market concentration at the supply side can result in even higher peak-load prices. Demand response by shifting demand from peak to base-load periods can counteract the market power in the peak-load. However, demand response has so far been modest since the current short-term price elasticity seems to be small. This is also the case for related markets, for example, green certificates where the demand is determined as a percentage of the power demand, or for heat and natural gas markets. This raises a number of interesting research issues: 1) Demand response in different energy markets, 2) Estimation of price elasticity and flexibility, 3) Stimulation of demand response, 4) Regulation, policy and modelling aspects, 5) Demand response and market power at the supply side, 6) Energy security of supply, 7) Demand response in forward, spot, ancillary service, balance and capacity markets, 8) Demand response in deviated markets, e.g., emission, futures, and green certificate markets, 9) Value of increased demand response, 10) Flexible households. (BA)

Supplies should match growing demand

International Nuclear Information System (INIS)

Rasmusen, H.J.

1997-01-01

The natural gas industry is currently enjoying healthy growth prospects. Not only is the demand for natural gas steadily growing; the outlook for increasing gas reserves is promising as well. The success of natural gas in the marketplace reflects, on one hand, continuous attention paid to public and customer requirements and, on the other hand, the ability of the gas industry to direct technological developments toward the increasing public demand for gas at competitive market prices supplied in a reliable, safe and environmentally friendly manner. In the past, the gas industry has been involved in the development of technologies for everything from gas production to the end user and from borehole to burner tip, and the author believes that the industry must continue or even increase its emphasis on technology in the future in order to capture new market opportunities. He explains this by looking at the supply side, the demand side and the structural side of the business

Mechanical and Microstructural Properties of Friction Welded AISI 304 Stainless Steel to AISI 1060 Steel AISI 1060

Directory of Open Access Journals (Sweden)

Ates H.

2014-10-01

Full Text Available Rotary Friction welding is one of the most popular methods of joining similar and dissimilar materials. It is widely used with metals and thermoplastics in a wide variety of aviation, transport and aerospace industrial component designs. This study investigates the influence of friction and upsetting pressures on the hardness, tensile properties and microstructure of the welds. The experimental results showed that as the friction and upsetting pressures increased, the hardness and tensile strength values increased, as well. The tensile fracture of welded joint occurred in the AISI 1060 side. The friction processed joints were evaluated for their integrity and quality aspects by optical and scanning electron microscopy. For the perfect interfacial bonding, sufficient upsetting and friction pressures are necessary to reach the optimal temperature and severe plastic deformation to bring these materials within the attraction range.

An Improved Fuzzy C-Means Algorithm for the Implementation of Demand Side Management Measures

Directory of Open Access Journals (Sweden)

Ioannis Panapakidis

2017-09-01

Full Text Available Load profiling refers to a procedure that leads to the formulation of daily load curves and consumer classes regarding the similarity of the curve shapes. This procedure incorporates a set of unsupervised machine learning algorithms. While many crisp clustering algorithms have been proposed for grouping load curves into clusters, only one soft clustering algorithm is utilized for the aforementioned purpose, namely the Fuzzy C-Means (FCM algorithm. Since the benefits of soft clustering are demonstrated in a variety of applications, the potential of introducing a novel modification of the FCM in the electricity consumer clustering process is examined. Additionally, this paper proposes a novel Demand Side Management (DSM strategy for load management of consumers that are eligible for the implementation of Real-Time Pricing (RTP schemes. The DSM strategy is formulated as a constrained optimization problem that can be easily solved and therefore, making it a useful tool for retailers’ decision-making framework in competitive electricity markets.

A demand-side approach to the optimal deployment of electric vehicle charging stations in metropolitan areas

International Nuclear Information System (INIS)

Andrenacci, N.; Ragona, R.; Valenti, G.

2016-01-01

Highlights: • A demand-side approach to the location of charging infrastructure problem is discussed in the paper. • The analysis is based on a large data-set of private vehicle travels within the urban area of Rome. • Cluster analysis is applied to the data to find the optimal location zones for charging infrastructures. • The daily energy demand and the average number of users per day are calculated for each and every charging infrastructure. - Abstract: Despite all the acknowledged advantages in terms of environmental impact reduction, energy efficiency and noise reduction, the electric mobility market is below expectations. In fact, electric vehicles have limitations that pose several important challenges for achieving a sustainable mobility system: among them, the availability of an adequate charging infrastructure is recognized as a fundamental requirement and appropriate approaches to optimize public and private investments in this field are to be delineated. In this paper we consider actual data on conventional private vehicle usage in the urban area of Rome to carry out a strategy for the optimal allocation of charging infrastructures into portions (subareas) of the urban area, based on an analysis of a driver sample under the assumption of a complete switch to an equivalent fleet of electric vehicles. Moreover, the energy requirement for each one of the subareas is estimated in terms of the electric energy used by the equivalent fleet of electric vehicles to reach their destination. The model can be easily generalized to other problems regarding facility allocation based on user demand.

Feasibility and potential of thermal demand side management in residential buildings considering different developments in the German energy market

International Nuclear Information System (INIS)

Wolisz, Henryk; Punkenburg, Carl; Streblow, Rita; Müller, Dirk

2016-01-01

Highlights: • A scenario analysis for the German energy market in the year 2030 is performed. • Growing demand for flexible electric capacities is identified in all scenarios. • Significant potential for domestic demand side management is identified. • A distinct potential for dynamic operation of domestic supply systems is found. • The necessity for a quick introduction of smart metering and control is found. - Abstract: A transition in the electricity market is required to manage the volatility of increasing renewable energy generation. These fluctuations can be faced with flexible consumption through Demand Side Management (DSM), establishment of further centralized storage capacities and provisioning of dynamic back up generation capacities. At least the latter two options can impose large establishment and operation costs upon the electricity market. Therefore, the feasibility and the resulting potential of coupling the electricity grid with the thermal supply of residential buildings is analysed in this paper. Thereby, inexpensive and widespread thermal storage capacities could be used to improve the integration of dynamic renewable electricity generation. In this paper the technical and economical key impact factors for such thermal DSM approach are elaborated. Based on a literature review, the identified key factors are aggregated to form consistent scenarios of the German “Energiewende” (turnaround in energy policy). The practicability and possible magnitude of the intended DSM is then analysed based on the identified scenarios. All resulting scenarios highlight the growing demand for a flexible electricity market. Especially in scenarios with strong growth of renewable electricity generation, up to 45 GW of flexible electric capacities would be required in Germany by the year 2030. Furthermore, the analysis demonstrates that independently of the energy market development, it is very likely that electricity coupled supply systems will

Identification of GMS friction model without friction force measurement

International Nuclear Information System (INIS)

Grami, Said; Aissaoui, Hicham

2011-01-01

This paper deals with an online identification of the Generalized Maxwell Slip (GMS) friction model for both presliding and sliding regime at the same time. This identification is based on robust adaptive observer without friction force measurement. To apply the observer, a new approach of calculating the filtered friction force from the measurable signals is introduced. Moreover, two approximations are proposed to get the friction model linear over the unknown parameters and an approach of suitable filtering is introduced to guarantee the continuity of the model. Simulation results are presented to prove the efficiency of the approach of identification.

Bioinspired orientation-dependent friction.

Science.gov (United States)

Xue, Longjian; Iturri, Jagoba; Kappl, Michael; Butt, Hans-Jürgen; del Campo, Aránzazu

2014-09-23

Spatular terminals on the toe pads of a gecko play an important role in directional adhesion and friction required for reversible attachment. Inspired by the toe pad design of a gecko, we study friction of polydimethylsiloxane (PDMS) micropillars terminated with asymmetric (spatular-shaped) overhangs. Friction forces in the direction of and against the spatular end were evaluated and compared to friction forces on symmetric T-shaped pillars and pillars without overhangs. The shape of friction curves and the values of friction forces on spatula-terminated pillars were orientation-dependent. Kinetic friction forces were enhanced when shearing against the spatular end, while static friction was stronger in the direction toward the spatular end. The overall friction force was higher in the direction against the spatula end. The maximum value was limited by the mechanical stability of the overhangs during shear. The aspect ratio of the pillar had a strong influence on the magnitude of the friction force, and its contribution surpassed and masked that of the spatular tip for aspect ratios of >2.

Demand as Frequency Controlled Reserve

DEFF Research Database (Denmark)

Xu, Zhao; Østergaard, Jacob; Togeby, Mikael

2011-01-01

Relying on generation side alone is deemed insufficient to fulfill the system balancing needs for future Danish power system, where a 50% wind penetration is outlined by the government for year 2025. This paper investigates using the electricity demand as frequency controlled reserve (DFR) as a new...... balancing measure, which has a high potential and can provide many advantages. Firstly, the background of the research is reviewed, including conventional power system reserves and the electricity demand side potentials. Subsequently, the control logics and corresponding design considerations for the DFR...

Financial incentives for DSM [demand-side management]: Theory and practice

International Nuclear Information System (INIS)

Reid, M.W.

1990-01-01

Recent efforts to provide incentives for electric utilities in the USA to undertake demand-side management (DSM) programs are reviewed. The major need for incentives is seen as the overcoming of disincentives inherent in traditional regulation that affect utilities' interest in, and motivation for, DSM programs. These disincentives include the failure to recover all program costs, loss of revenues, and loss of financial opportunity. In addition, utilities seldom perceive DSM as a low-risk proposition; principal areas of concern include regulatory risk, competitive risk, and balance sheet risk. In view of these disincentives and risks, any DSM program therefore should provide for full and timely recovery of all program costs; adjust for DSM-induced revenue losses; and counterbalance risk and loss of financial opportunity by providing a bonus above cost. Three utility-specific incentive proposals are presented for the case of utilities in New York, Massachusetts, and Pennsylvania. Each of these programs meets the goal of overcoming the disincentives that surround utility DSM programs. The most significant differences across the mechanisms are found in the bonus component. Mechanisms that reduce the utility's uncertainty about the receipt of a bonus by providing it in a lump sum will likely prove more powerful motivators than those that spread the bonus out over a period of years. Use of preapproved per-unit or per-customer impact measurements reduces uncertainty and thus increases the apparent value of the bonus. Annual review of program plans and assumed impacts, supported by continuing evaluation activities, minimizes the risk that the utilities will gamble with the system or receive excessive awards. 6 refs

Impact of Demand-Side Management on Thermal Comfort and Energy Costs in a Residential nZEB

Directory of Open Access Journals (Sweden)

Thibault Q. Péan

2017-05-01

Full Text Available In this study, simulation work has been carried out to investigate the impact of a demand-side management control strategy in a residential nZEB. A refurbished apartment within a multi-family dwelling representative of Mediterranean building habits was chosen as a study case and modelled within a simulation framework. A flexibility strategy based on set-point modulation depending on the energy price was applied to the building. The impact of the control strategy on thermal comfort was studied in detail with several methods retrieved from the standards or other literature, differentiating the effects on day and night living zones. It revealed a slight decrease of comfort when implementing flexibility, although this was not prejudicial. In addition, the applied strategy caused a simultaneous increase of the electricity used for heating by up to 7% and a reduction of the corresponding energy costs by up to around 20%. The proposed control thereby constitutes a promising solution for shifting heating loads towards periods of lower prices and is able to provide benefits for both the user and the grid sides. Beyond that, the activation of energy flexibility in buildings (nZEB in the present case will participate in a more successful integration of renewable energy sources (RES in the energy mix.

The investigation of abnormal particle-coarsening phenomena in friction stir repair weld of 2219-T6 aluminum alloy

International Nuclear Information System (INIS)

Li, Bo; Shen, Yifu

2011-01-01

Highlights: → Defective friction stir welds were repaired by overlapping FSW technique. → Abnormal Al 2 Cu-coarsening phenomena were found in 2219-T6 friction stir repair weld. → Three formation mechanisms were proposed for reasonable explanations. -- Abstract: The single-pass friction stir weld of aluminum 2219-T6 with weld-defects was repaired by overlapping friction stir welding technique. However, without any post weld heat treatment process, it was found that the phenomena of abnormal particle-coarsening of Al 2 Cu had occurred in the overlapping friction stir repair welds. The detecting results of non-destructive X-ray inspection proved that not only one group of repair FSW process parameters could lead to occurrence of the abnormal phenomena. And the abnormally coarsened particles always appeared on the advancing side of repair welds rather than the retreating side where the fracture behaviors occurred after mechanical tensile testing. The size of the biggest particle lying in the dark bands of 'Onion-rings' was more than 150 μm. After the related investigation by scanning electron microscope and X-ray energy spectrometer, three types of formation mechanisms were proposed for reasonably explaining the abnormal phenomenon: Aggregation Mechanism, Diffusion Mechanisms I and II. Aggregation Mechanism was according to the motion-laws of stir-pin. Diffusion Mechanisms were based on the classical theories of precipitate growth in metallic systems. The combined action of the three detailed mechanisms contributed to the abnormal coarsening behavior of Al 2 Cu particles in the friction stir repair weld.

Benefits of Demand-Side Response in Providing Frequency Response Service in the Future GB Power System

Energy Technology Data Exchange (ETDEWEB)

Teng, Fei, E-mail: fei.teng09@imperial.ac.uk; Aunedi, Marko; Pudjianto, Danny; Strbac, Goran [Department of Electrical and Electronic Engineering, Imperial College London, London (United Kingdom)

2015-08-18

The demand for ancillary service is expected to increase significantly in the future Great Britain (GB) electricity system due to high penetration of wind. In particular, the need for frequency response, required to deal with sudden frequency drops following a loss of generator, will increase because of the limited inertia capability of wind plants. This paper quantifies the requirements for primary frequency response and analyses the benefits of frequency response provision from demand-side response (DSR). The results show dramatic changes in frequency response requirements driven by high penetration of wind. Case studies carried out by using an advanced stochastic generation scheduling model suggest that the provision of frequency response from DSR could greatly reduce the system operation cost, wind curtailment, and carbon emissions in the future GB system characterized by high penetration of wind. Furthermore, the results demonstrate that the benefit of DSR shows significant diurnal and seasonal variation, whereas an even more rapid (instant) delivery of frequency response from DSR could provide significant additional value. Our studies also indicate that the competing technologies to DSR, namely battery storage, and more flexible generation could potentially reduce its value by up to 35%, still leaving significant room to deploy DSR as frequency response provider.

Benefits of Demand-Side Response in Providing Frequency Response Service in the Future GB Power System

International Nuclear Information System (INIS)

Teng, Fei; Aunedi, Marko; Pudjianto, Danny; Strbac, Goran

2015-01-01

The demand for ancillary service is expected to increase significantly in the future Great Britain (GB) electricity system due to high penetration of wind. In particular, the need for frequency response, required to deal with sudden frequency drops following a loss of generator, will increase because of the limited inertia capability of wind plants. This paper quantifies the requirements for primary frequency response and analyses the benefits of frequency response provision from demand-side response (DSR). The results show dramatic changes in frequency response requirements driven by high penetration of wind. Case studies carried out by using an advanced stochastic generation scheduling model suggest that the provision of frequency response from DSR could greatly reduce the system operation cost, wind curtailment, and carbon emissions in the future GB system characterized by high penetration of wind. Furthermore, the results demonstrate that the benefit of DSR shows significant diurnal and seasonal variation, whereas an even more rapid (instant) delivery of frequency response from DSR could provide significant additional value. Our studies also indicate that the competing technologies to DSR, namely battery storage, and more flexible generation could potentially reduce its value by up to 35%, still leaving significant room to deploy DSR as frequency response provider.

Distributed MPC applied to power demand side control

NARCIS (Netherlands)

Larsen, G.K.H.; Pons, J.; Achterop, S.; Scherpen, J.M.A.

2013-01-01

In the future, global energy balance of a smart grid system can be achieved by its agents deciding on their own power demand locally and the exchange of these decisions. In this paper, we model a network of households with washing machine programs that can be shifted in time so that the overall

Novel algorithm for aggregated demand response strategy for smart distribution network

NARCIS (Netherlands)

Babar, M.; Ahamed, I.; Shah, A.; Al-Ammar, E.A.; Malik, N.H.

2013-01-01

Advancement in demand side management strategies enables smart grid to cope with the ever increasing energy demand and provide economic benefit to all of it's stakeholders. Moreover, emerging concept of smart pricing and advances in load control can provide new business opportunities for demand side

Lower extremity kinematics that correlate with success in lateral load transfers over a low friction surface.

Science.gov (United States)

Catena, Robert D; Xu, Xu

2015-01-01

We previously studied balance during lateral load transfers, but were left without explanation of why some individuals were successful in novel low friction conditions and others were not. Here, we retrospectively examined lower extremity kinematics between successful (SL) and unsuccessful (UL) groups to determine what characteristics may improve low friction performance. Success versus failure over a novel slippery surface was used to dichotomise 35 healthy working-age individuals into the two groups (SL and UL). Participants performed lateral load transfers over three sequential surface conditions: high friction, novel low friction, and practiced low friction. The UL group used a wide stance with rotation mostly at the hips during the high and novel low friction conditions. To successfully complete the practiced low friction task, they narrowed their stance and pivoted both feet and torso towards the direction of the load, similar to the SL group in all conditions. This successful kinematic method potentially results in reduced muscle demand throughout the task. Practitioner Summary: The reason for this paper is to retrospectively examine the different load transfer strategies that are used in a low friction lateral load transfer. We found stance width to be the major source of success, while sagittal plane motion was altered to potentially maintain balance.

Science friction: data, metadata, and collaboration.

Science.gov (United States)

Edwards, Paul N; Mayernik, Matthew S; Batcheller, Archer L; Bowker, Geoffrey C; Borgman, Christine L

2011-10-01

When scientists from two or more disciplines work together on related problems, they often face what we call 'science friction'. As science becomes more data-driven, collaborative, and interdisciplinary, demand increases for interoperability among data, tools, and services. Metadata--usually viewed simply as 'data about data', describing objects such as books, journal articles, or datasets--serve key roles in interoperability. Yet we find that metadata may be a source of friction between scientific collaborators, impeding data sharing. We propose an alternative view of metadata, focusing on its role in an ephemeral process of scientific communication, rather than as an enduring outcome or product. We report examples of highly useful, yet ad hoc, incomplete, loosely structured, and mutable, descriptions of data found in our ethnographic studies of several large projects in the environmental sciences. Based on this evidence, we argue that while metadata products can be powerful resources, usually they must be supplemented with metadata processes. Metadata-as-process suggests the very large role of the ad hoc, the incomplete, and the unfinished in everyday scientific work.

Demand side management in a day-ahead wholesale market: A comparison of industrial & social welfare approaches

International Nuclear Information System (INIS)

Jiang, Bo; Farid, Amro M.; Youcef-Toumi, Kamal

2015-01-01

Highlights: • We compare two demand side management in a day-ahead electricity wholesale market. • We develop and reconcile social welfare & industrial DSM mathematical models. • We show the industrial netload has an additional forecast quantity of baseline. • We analytically and numerically show the model equivalence with accurate baseline. • We numerically demonstrate the baseline errors lead to higher and costlier dispatch. - Abstract: The intermittent nature of renewable energy has been discussed in the context of the operational challenges that it brings to electrical grid reliability. Demand side management (DSM) with its ability to allow customers to adjust electricity consumption in response to market signals has often been recognized as an efficient way to mitigate the variable effects of renewable energy as well as to increase system efficiency and reduce system costs. However, the academic & industrial literature have taken divergent approaches to DSM implementation. While the popular approach among academia adopts a social welfare maximization formulation, the industrial practice compensates customers according to their load reduction from a predefined electricity consumption baseline that would have occurred without DSM. This paper rigorously compares these two different approaches in a day-ahead wholesale market context analytically and in a test case using the same system configuration and mathematical formalism. The comparison of the two models showed that a proper reconciliation of the two models might make them mitigate the stochastic netload in fundamentally the same way, but only under very specific conditions which are rarely met in practice. While the social welfare model uses a stochastic net load composed of two terms, the industrial DSM model uses a stochastic net load composed of three terms including the additional baseline term. DSM participants are likely to manipulate the baseline in order to receive greater financial

Survey of Models on Demand, Customer Base-Line and Demand Response and Their Relationships in the Power Market

OpenAIRE

Heshmati, Almas

2012-01-01

The increasing use of demand-side management as a tool to reliably meet electricity demand at peak time has stimulated interest among researchers, consumers and producer organizations, managers, regulators and policymakers, This research reviews the growing literature on models used to study demand, consumer baseline (CBL) and demand response in the electricity market. After characterizing the general demand models, it reviews consumer baseline based on which further study the demand response...

Real-Time Dynamic Observation of Micro-Friction on the Contact Interface of Friction Lining

Science.gov (United States)

Zhang, Dekun; Chen, Kai; Guo, Yongbo

2018-01-01

This paper aims to investigate the microscopic friction mechanism based on in situ microscopic observation in order to record the deformation and contact situation of friction lining during the frictional process. The results show that friction coefficient increased with the shear deformation and energy loss of the surfacee, respectively. Furthermore, the friction mechanism mainly included adhesive friction in the high-pressure and high-speed conditions, whereas hysteresis friction was in the low-pressure and low-speed conditions. The mixed-friction mechanism was in the period when the working conditions varied from high pressure and speed to low pressure and speed. PMID:29498677

Subdigital setae of chameleon feet: friction-enhancing microstructures for a wide range of substrate roughness.

Science.gov (United States)

Spinner, Marlene; Westhoff, Guido; Gorb, Stanislav N

2014-06-27

Hairy adhesive systems of microscopic setae with triangular flattened tips have evolved convergently in spiders, insects and arboreal lizards. The ventral sides of the feet and tails in chameleons are also covered with setae. However, chameleon setae feature strongly elongated narrow spatulae or fibrous tips. The friction enhancing function of these microstructures has so far only been demonstrated in contact with glass spheres. In the present study, the frictional properties of subdigital setae of Chamaeleo calyptratus were measured under normal forces in the physical range on plane substrates having different roughness. We showed that chameleon setae maximize friction on a wide range of substrate roughness. The highest friction was measured on asperities of 1 μm. However, our observations of the climbing ability of Ch. calyptratus on rods of different diameters revealed that also claws and grasping feet are additionally responsible for the force generation on various substrates during locomotion.

Friction of elastomer-on-glass system and direct observation of its frictional interface

International Nuclear Information System (INIS)

Okamoto, Yoshihiro; Nishio, Kazuyuki; Sugiura, Jun-ichi; Hirano, Motohisa; Nitta, Takahiro

2007-01-01

We performed a study on the static friction of PDMS elastomers with well-defined surface topography sliding over glass. An experimental setup for simultaneous measurements of friction force and direct observations of frictional interface has been developed. The static friction force was nearly proportional to normal load. The static friction force was independent of stick time. The simultaneous measurements revealed that the static friction force was proportional to the total area of contact. The coefficient was nearly independent of the surface topography of PDMS elastomers

Optimal energy efficiency policies and regulatory demand-side management tests: How well do they match?

International Nuclear Information System (INIS)

Brennan, Timothy J.

2010-01-01

Under conventional models, subsidizing energy efficiency requires electricity to be priced below marginal cost. Its benefits increase when electricity prices increase to finance the subsidy. With high prices, subsidies are counterproductive unless consumers fail to make efficiency investments when private benefits exceed costs. If the gain from adopting efficiency is only reduced electricity spending, capping revenues from energy sales may induce a utility to substitute efficiency for generation when the former is less costly. This goes beyond standard 'decoupling' of distribution revenues from sales, requiring complex energy price regulation. The models' results are used to evaluate tests in the 2002 California Standard Practice Manual for assessing demand-side management programs. Its 'Ratepayer Impact Measure' test best conforms to the condition that electricity price is too low. Its 'Total Resource Cost' and 'Societal Cost' tests resemble the condition for expanded decoupling. No test incorporates optimality conditions apart from consumer choice failure.

The Problems of Estonian R&D and Innovation Strategy and the Demand-Side Innovation Policies

Directory of Open Access Journals (Sweden)

Tõnu Roolaht

2012-12-01

Full Text Available The second larger Estonian R&D and Innovation Strategy ‘Knowledge-based Estonia 2007-2013’ is aimed at continuing the advancement of research and development efforts towards an innovative knowledge-based society and economic system in Estonia. Fostering of knowledge-based high-tech industries is seen as paramount for retaining country’s competitive advantage. However, the mid-term evaluations indicate that several goals of the strategy might not be achievable by 2013. In fact, the policy measures have been much more successful in developing scientific research, as indicated by increased international publication, number of patents, and number of researchers and engineers. The advances in development of high-tech products and services through innovations are noticeable but less prominent. The purpose of this study is to suggest the role for demand-side innovation policies in helping to advance commercial development and innovation

Search Frictions, Job Flows and Optimal Monetary Policy

OpenAIRE

Shoujian Zhang

2014-01-01

Job creation and job destruction are investigated in an economy featured by search frictions in both labour and goods markets. We show that both the unemployment rate and the endogenous job destruction rate increase when the inflation rate rises, because the demand declines due to the increase in the cost of holding money. Our numerical exercises suggest that the destruction of lower productivity jobs and the creation of higher productivity jobs may be inefficiently low under the zero nominal...

Comparison of frictional resistance of esthetic and semi-esthetic self-ligating brackets

Directory of Open Access Journals (Sweden)

M S Kannan

2015-01-01

Full Text Available Aim: The frictional resistance encountered during sliding mechanics has been well established in the orthodontic literature, and it consists of complex interactions between the bracket, archwire, and method of ligation the claim of reduced friction with self-ligating brackets is often cited as a primary advantage over conventional brackets. This study was done to compare and evaluate the frictional forces generated between fully esthetic brackets and semi-aesthetic self-ligating brackets, which are of passive form and SEM (scanning electron microscope study of the Brackets after Frictional evaluation. Materials and Methods: Two types of self-ligating esthetic brackets, Damon clear (Ormco made of fully ceramic and Opal (Ultradent Products, USA and, Two types of self-ligating semi-esthetic brackets, Clarity SL (3M Unitek and Damon 3 (Ormco both of which are made of ceramic with metal slot. Arch wires with different dimensions and quality 17 × 25, 19 × 25 Titanium Molybdenum Alloy (TMA and 17 × 25, 19 × 25 stainless steel that came from plain strands of wire were used for frictional comparison test. The brackets used in this study had 0.022 × 0.028 inch slot. Results: The statistical tests showed significantly smaller amount of kinetic frictional forces is generated by Damon 3 (semi-esthetic self-ligating brackets. For each wire used, Damon 3 displayed significantly lower frictional forces (P ≤ 0.05 than any of the self-ligating system, followed by Opal (fully esthetic self-ligating brackets which generated smaller amount of frictional forces but relatively on the higher side when compared with Damon 3. Damon clear (fully esthetic self-ligating brackets generated the maximum amount of kinetic forces with all types of wire dimensions and properties when compared to the other three types of self-ligating system. Clarity SL (semi-esthetic self-ligating brackets generated smaller amount of frictional forces when compared with Damon clear and

Comparison of frictional resistance of esthetic and semi-esthetic self-ligating brackets.

Science.gov (United States)

Kannan, M S; Murali, R V; Kishorekumar, S; Gnanashanmugam, K; Jayanth, V

2015-04-01

The frictional resistance encountered during sliding mechanics has been well established in the orthodontic literature, and it consists of complex interactions between the bracket, archwire, and method of ligation the claim of reduced friction with self-ligating brackets is often cited as a primary advantage over conventional brackets. This study was done to compare and evaluate the frictional forces generated between fully esthetic brackets and semi-aesthetic self-ligating brackets, which are of passive form and SEM (scanning electron microscope) study of the Brackets after Frictional evaluation. Two types of self-ligating esthetic brackets, Damon clear (Ormco) made of fully ceramic and Opal (Ultradent Products, USA) and, Two types of self-ligating semi-esthetic brackets, Clarity SL (3M Unitek) and Damon 3 (Ormco) both of which are made of ceramic with metal slot. Arch wires with different dimensions and quality 17 × 25, 19 × 25 Titanium Molybdenum Alloy (TMA) and 17 × 25, 19 × 25 stainless steel that came from plain strands of wire were used for frictional comparison test. The brackets used in this study had 0.022 × 0.028 inch slot. The statistical tests showed significantly smaller amount of kinetic frictional forces is generated by Damon 3 (semi-esthetic self-ligating brackets). For each wire used, Damon 3 displayed significantly lower frictional forces (P ≤ 0.05) than any of the self-ligating system, followed by Opal (fully esthetic self-ligating brackets) which generated smaller amount of frictional forces but relatively on the higher side when compared with Damon 3. Damon clear (fully esthetic self-ligating brackets) generated the maximum amount of kinetic forces with all types of wire dimensions and properties when compared to the other three types of self-ligating system. Clarity SL (semi-esthetic self-ligating brackets) generated smaller amount of frictional forces when compared with Damon clear and relatively higher amount of frictional forces

Transactive Demand Side Management Programs in Smart Grids with High Penetration of EVs

Directory of Open Access Journals (Sweden)

Poria Hasanpor Divshali

2017-10-01

Full Text Available Due to environmental concerns, economic issues, and emerging new loads, such as electrical vehicles (EVs, the importance of demand side management (DSM programs has increased in recent years. DSM programs using a dynamic real-time pricing (RTP method can help to adaptively control the electricity consumption. However, the existing RTP methods, particularly when they consider the EVs and the power system constraints, have many limitations, such as computational complexity and the need for centralized control. Therefore, a new transactive DSM program is proposed in this paper using an imperfect competition model with high EV penetration levels. In particular, a heuristic two-stage iterative method, considering the influence of decisions made independently by customers to minimize their own costs, is developed to find the market equilibrium quickly in a distributed manner. Simulations in the IEEE 37-bus system with 1141 customers and 670 EVs are performed to demonstrate the effectiveness of the proposed method. The results show that the proposed method can better manage the EVs and elastic appliances than the existing methods in terms of power constraints and cost. Also, the proposed method can solve the optimization problem quick enough to run in real-time.

Modeling Friction Performance of Drill String Torsional Oscillation Using Dynamic Friction Model

Directory of Open Access Journals (Sweden)

Xingming Wang

2017-01-01

Full Text Available Drill string torsional and longitudinal oscillation can significantly reduce axial drag in horizontal drilling. An improved theoretical model for the analysis of the frictional force was proposed based on microscopic contact deformation theory and a bristle model. The established model, an improved dynamic friction model established for drill strings in a wellbore, was used to determine the relationship of friction force changes and the drill string torsional vibration. The model results were in good agreement with the experimental data, verifying the accuracy of the established model. The analysis of the influence of drilling mud properties indicated that there is an approximately linear relationship between the axial friction force and dynamic shear and viscosity. The influence of drill string torsional oscillation on the axial friction force is discussed. The results indicated that the drill string transverse velocity is a prerequisite for reducing axial friction. In addition, low amplitude of torsional vibration speed can significantly reduce axial friction. Then, increasing the amplitude of transverse vibration speed, the effect of axial reduction is not significant. In addition, by involving general field drilling parameters, this model can accurately describe the friction behavior and quantitatively predict the frictional resistance in horizontal drilling.

Frictional ageing from interfacial bonding and the origins of rate and state friction.

Science.gov (United States)

Li, Qunyang; Tullis, Terry E; Goldsby, David; Carpick, Robert W

2011-11-30

Earthquakes have long been recognized as being the result of stick-slip frictional instabilities. Over the past few decades, laboratory studies of rock friction have elucidated many aspects of tectonic fault zone processes and earthquake phenomena. Typically, the static friction of rocks grows logarithmically with time when they are held in stationary contact, but the mechanism responsible for this strengthening is not understood. This time-dependent increase of frictional strength, or frictional ageing, is one manifestation of the 'evolution effect' in rate and state friction theory. A prevailing view is that the time dependence of rock friction results from increases in contact area caused by creep of contacting asperities. Here we present the results of atomic force microscopy experiments that instead show that frictional ageing arises from the formation of interfacial chemical bonds, and the large magnitude of ageing at the nanometre scale is quantitatively consistent with what is required to explain observations in macroscopic rock friction experiments. The relative magnitude of the evolution effect compared with that of the 'direct effect'--the dependence of friction on instantaneous changes in slip velocity--determine whether unstable slip, leading to earthquakes, is possible. Understanding the mechanism underlying the evolution effect would enable us to formulate physically based frictional constitutive laws, rather than the current empirically based 'laws', allowing more confident extrapolation to natural faults.

Translational friction coefficient of a permeable cylinder in a sheet of viscous fluid

NARCIS (Netherlands)

Wiegel, F.W.

1979-01-01

The author calculates the translational friction coefficient and the translational diffusion coefficient of a permeable cylinder moving in a sheet of fluid which is embedded on both sides in a fluid of much lower viscosity. The result, which is an asymptotic expression valid in the limit of small

Investigation of squeal noise under positive friction characteristics condition provided by friction modifiers

Science.gov (United States)

Liu, Xiaogang; Meehan, Paul A.

2016-06-01

Field application of friction modifiers on the top of rail has been shown to effectively curb squeal and reduce lateral forces, but performance can be variable, according to other relevant research. Up to now, most investigations of friction modifiers were conducted in the field, where it is difficult to control or measure important parameters such as angle of attack, rolling speed, adhesion ratio etc. In the present investigation, the effect of different friction modifiers on the occurrence of squeal was investigated on a rolling contact two disk test rig. In particular, friction-creep curves and squeal sound pressure levels were measured under different rolling speeds and friction modifiers. The results show friction modifiers can eliminate or reduce the negative slope of friction-creep curves, but squeal noise still exists. Theoretical modelling of instantaneous creep behaviours reveals a possible reason why wheel squeal still exists after the application of friction modifiers.

Resetting of Quartz OSL (optically stimulated luminescence) Signals by Frictional Heating in Experimentally Sheared Gouges at Seismic Slip Rates.

Science.gov (United States)

Kim, J. H.; Choi, J. H.; Chauhan, N.; Lee, S.; Hirose, T.; Ree, J. H.

2014-12-01

Recent studies on natural and experimental seismic faults have revealed that frictional heating plays an important role in earthquake dynamics as well as in producing mineralogical and microstructural signatures of seismic faulting. Here, we report changes in OSL signals in quartz by frictional heating in experimental fault gouges. The gouges (80% of quartz and 20% of bentonite by weight) with a thickness of 1 mm were sheared between sandstone cylinders (diameter: 25 mm) at a normal stress of 1 MPa and slip rate of 1.31 m/s. The quartz grains from a sand dune on the western coast of South Korea were sieved to select size fractions between 90 and 250 μm. The equivalent dose (De) of the undeformed quartz grains was 8.0 ± 0.3 Gy. Upon displacement, the friction abruptly increases to the 1st peak (with friction coefficient μ ≈ 0.75) followed by slip weakening. Then the fault zones show two more peak frictions (μ ≈ 0.53~0.75) and finally reach a steady-state friction (μ ≈ 0.2~0.35). The fault can be divided into three zones based grain size (thus slip rate); slip localization (SLZ), intermediate slip-rate (ISZ) and low slip-rate (LSZ) zones. SLZ develops adjacent to the moving side of the sandstone cylinder with P-foliation and shear band. The size of quartz (Dq) in ISZ and LSZ is 5-30 μm and 50-250 μm, respectively. SEM and TEM analyses indicate that the fault gouge of SLZ consists of subangular quartz clasts (Dq ≈ 3 μm) and matrix of nano-scale quartz, unidentified silicate minerals and amorphous material. The fault zones were sectioned into six layers (~160 µm thick for each layer) parallel to the fault zone boundary for OSL analyses. Quartz grains from all the layers except the one immediately adjacent to the stationary side of the sandstone cylinder show De of 'effectively' 0 Gy indicating a full resetting of OSL signals. The partial resetting of OSL signal in the layer adjacent to the stationary side of the cylinder indicates the temperature (T

Frictional coefficient depending on active friction radius with BPV ...

African Journals Online (AJOL)

Frictional coefficient depending on active friction radius with BPV and BTV in automobile disc braking system. ... International Journal of Engineering, Science and Technology. Journal Home · ABOUT ... AJOL African Journals Online. HOW TO ...

Evaluating demand side measures in simulation models for the power market

International Nuclear Information System (INIS)

Wolfgang, Ove; Doorman, Gerard

2011-01-01

Increased energy efficiency is one of the pillars for reducing CO 2 emissions. However, in models for the electricity market like unit commitment and dispatch models, increased efficiency of demand results in a paradoxical apparent reduction of the total economic surplus. The reason is that these are partial models for the electricity market, which do not take into account the effect of the changes in other markets. This paper shows how the calculation of the consumer surplus in the electricity market should be corrected to take into account the effect in other markets. In different cases we study shifts in the demand curve that are caused by increased energy efficiency, reduced cost for substitutes to electricity and real-time monitoring of demand, and we derive the necessary correction. The correction can easily be included in existing simulation models, and makes it possible to assess the effect of changes in demand on economic surplus. (author)

Friction analysis of kinetic schemes : the friction coefficient

NARCIS (Netherlands)

Lolkema, Juke S.

1995-01-01

Friction analysis is proposed as the application of general control analysis to single enzymes to describe the control of elementary kinetic steps on the overall catalytic rate. For each transition, a friction coefficient is defined that measures the sensitivity of the turnover rate to the free

On the nature of the static friction, kinetic friction and creep

DEFF Research Database (Denmark)

Persson, B. N. J.; Albohr, O.; Mancosu, F.

2003-01-01

of capillary bridges. However, there is no single value of the static friction coefficient, since it depends upon the initial dwell time and on rate of starting.We argue that the correct basis for the Coulomb friction law, which states that the friction force is proportional to the normal load...

Versatile Friction Stir Welding/Friction Plug Welding System

Science.gov (United States)

Carter, Robert

2006-01-01

A proposed system of tooling, machinery, and control equipment would be capable of performing any of several friction stir welding (FSW) and friction plug welding (FPW) operations. These operations would include the following: Basic FSW; FSW with automated manipulation of the length of the pin tool in real time [the so-called auto-adjustable pin-tool (APT) capability]; Self-reacting FSW (SRFSW); SR-FSW with APT capability and/or real-time adjustment of the distance between the front and back shoulders; and Friction plug welding (FPW) [more specifically, friction push plug welding] or friction pull plug welding (FPPW) to close out the keyhole of, or to repair, an FSW or SR-FSW weld. Prior FSW and FPW systems have been capable of performing one or two of these operations, but none has thus far been capable of performing all of them. The proposed system would include a common tool that would have APT capability for both basic FSW and SR-FSW. Such a tool was described in Tool for Two Types of Friction Stir Welding (MFS- 31647-1), NASA Tech Briefs, Vol. 30, No. 10 (October 2006), page 70. Going beyond what was reported in the cited previous article, the common tool could be used in conjunction with a plug welding head to perform FPW or FPPW. Alternatively, the plug welding head could be integrated, along with the common tool, into a FSW head that would be capable of all of the aforementioned FSW and FPW operations. Any FSW or FPW operation could be performed under any combination of position and/or force control.

Proximity friction reexamined

International Nuclear Information System (INIS)

Krappe, H.J.

1989-01-01

The contribution of inelastic excitations to radial and tangential friction form-factors in heavy-ion collisions is investigated in the frame-work of perturbation theory. The dependence of the form factors on the essential geometrical and level-density parameters of the scattering system is exhibited in a rather closed form. The conditions for the existence of time-local friction coefficients are discussed. Results are compared to form factors from other models, in particular the transfer-related proximity friction. For the radial friction coefficient the inelastic excitation mechanism seems to be the dominant contribution in peripheral collisions. (orig.)

Lessons learned from new construction utility demand side management programs and their implications for implementing building energy codes

Energy Technology Data Exchange (ETDEWEB)

Wise, B.K.; Hughes, K.R.; Danko, S.L.; Gilbride, T.L.

1994-07-01

This report was prepared for the US Department of Energy (DOE) Office of Codes and Standards by the Pacific Northwest Laboratory (PNL) through its Building Energy Standards Program (BESP). The purpose of this task was to identify demand-side management (DSM) strategies for new construction that utilities have adopted or developed to promote energy-efficient design and construction. PNL conducted a survey of utilities and used the information gathered to extrapolate lessons learned and to identify evolving trends in utility new-construction DSM programs. The ultimate goal of the task is to identify opportunities where states might work collaboratively with utilities to promote the adoption, implementation, and enforcement of energy-efficient building energy codes.

Metering systems and demand-side management models applied to hybrid renewable energy systems in micro-grid configuration

International Nuclear Information System (INIS)

Blasques, L.C.M.; Pinho, J.T.

2012-01-01

This paper proposes a demand-side management model integrated to a metering system for hybrid renewable energy systems in micro-grid configuration. The proposal is based on the management problems verified in most of this kind of renewable hybrid systems installed in Brazil. The main idea is the implementation of a pre-paid metering system with some control functions that directly act on the consumer demand, restricting the consumption proportionally to the monthly availability of renewable energy. The result is a better distribution of the electricity consumption by month and by consumer, preventing that only one user, with larger purchasing power, consumes all the renewable energy available at some time period. The proportionality between the consumption and the renewable energy's availability has the objective to prevent a lack of energy stored and a high use of the diesel generator-set on months of low renewable potential. This paper also aims to contribute to the Brazilian regulation of renewable energy systems supplying micro-grids. - Highlights: ► Review of the Brazilian electricity regulation for small-scale isolated systems. ► Renewable systems are the most feasible option in several isolated communities. ► One proposal is to guarantee government subsidies for renewable energy systems. ► Smart electronic meters to create electricity restrictions for the consumers.

Bayesian Analysis of Demand Elasticity in the Italian Electricity Market

OpenAIRE

D'Errico, Maria; Bollino, Carlo

2015-01-01

The liberalization of the Italian electricity market is a decade old. Within these last ten years, the supply side has been extensively analyzed, but not the demand side. The aim of this paper is to provide a new method for estimation of the demand elasticity, based on Bayesian methods applied to the Italian electricity market. We used individual demand bids data in the day-ahead market in the Italian Power Exchange (IPEX), for 2011, in order to construct an aggregate demand function at the h...

Chemical origins of frictional aging.

Science.gov (United States)

Liu, Yun; Szlufarska, Izabela

2012-11-02

Although the basic laws of friction are simple enough to be taught in elementary physics classes and although friction has been widely studied for centuries, in the current state of knowledge it is still not possible to predict a friction force from fundamental principles. One of the highly debated topics in this field is the origin of static friction. For most macroscopic contacts between two solids, static friction will increase logarithmically with time, a phenomenon that is referred to as aging of the interface. One known reason for the logarithmic growth of static friction is the deformation creep in plastic contacts. However, this mechanism cannot explain frictional aging observed in the absence of roughness and plasticity. Here, we discover molecular mechanisms that can lead to a logarithmic increase of friction based purely on interfacial chemistry. Predictions of our model are consistent with published experimental data on the friction of silica.

Friction induced hunting limit cycles : a comparison between the LuGre and switch friction model

NARCIS (Netherlands)

Hensen, R.H.A.; Molengraft, van de M.J.G.; Steinbuch, M.

2003-01-01

In this paper, friction induced limit cycles are predicted for a simple motion system consisting of a motor-driven inertia subjected to friction and a PID-controlled regulator task. The two friction models used, i.e., (i) the dynamic LuGre friction model and (ii) the static switch friction model,

The past, present, and future of U.S. utility demand-side management programs

International Nuclear Information System (INIS)

Eto, J.

1996-12-01

Demand-side management or DSM refers to active efforts by electric and gas utilities to modify customers' energy use patterns. The experience in the US shows that utilities, when provided with appropriate incentives, can provide a powerful stimulus to energy efficiency in the private sector. This paper describes the range and history of DSM programs offered by US electric utilities, with a focus on the political, economic, and regulatory events that have shaped their evolution. It also describes the changes these programs are undergoing as a result of US electricity industry restructuring. DSM programs began modestly in the 1970s in response to growing concerns about dependence on foreign sources of oil and environmental consequences of electricity generation, especially nuclear power. The foundation for the unique US partnership between government and utility interests can be traced first to the private-ownership structure of the vertically integrated electricity industry and second to the monopoly franchise granted by state regulators. Electricity industry restructuring calls into question both of these basic conditions, and thus the future of utility DSM programs for the public interest. Future policies guiding ratepayer-funded energy-efficiency DSM programs will need to pay close attention to the specific market objectives of the programs and to the balance between public and private interests

The past, present, and future of U.S. utility demand-side management programs

Energy Technology Data Exchange (ETDEWEB)

Eto, J. [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technologies Div.

1996-12-01

Demand-side management or DSM refers to active efforts by electric and gas utilities to modify customers` energy use patterns. The experience in the US shows that utilities, when provided with appropriate incentives, can provide a powerful stimulus to energy efficiency in the private sector. This paper describes the range and history of DSM programs offered by US electric utilities, with a focus on the political, economic, and regulatory events that have shaped their evolution. It also describes the changes these programs are undergoing as a result of US electricity industry restructuring. DSM programs began modestly in the 1970s in response to growing concerns about dependence on foreign sources of oil and environmental consequences of electricity generation, especially nuclear power. The foundation for the unique US partnership between government and utility interests can be traced first to the private-ownership structure of the vertically integrated electricity industry and second to the monopoly franchise granted by state regulators. Electricity industry restructuring calls into question both of these basic conditions, and thus the future of utility DSM programs for the public interest. Future policies guiding ratepayer-funded energy-efficiency DSM programs will need to pay close attention to the specific market objectives of the programs and to the balance between public and private interests.

Novel friction law for the static friction force based on local precursor slipping.

Science.gov (United States)

Katano, Yu; Nakano, Ken; Otsuki, Michio; Matsukawa, Hiroshi

2014-09-10

The sliding of a solid object on a solid substrate requires a shear force that is larger than the maximum static friction force. It is commonly believed that the maximum static friction force is proportional to the loading force and does not depend on the apparent contact area. The ratio of the maximum static friction force to the loading force is called the static friction coefficient µM, which is considered to be a constant. Here, we conduct experiments demonstrating that the static friction force of a slider on a substrate follows a novel friction law under certain conditions. The magnitude of µM decreases as the loading force increases or as the apparent contact area decreases. This behavior is caused by the slip of local precursors before the onset of bulk sliding and is consistent with recent theory. The results of this study will develop novel methods for static friction control.

Static frictional resistance with the slide low-friction elastomeric ligature system.

Science.gov (United States)

Jones, Steven P; Ben Bihi, Saida

2009-11-01

This ex-vivo study compared the static frictional resistance of a low-friction ligation system against a conventional elastomeric module, and studied the effect of storage in a simulated oral environment on the static frictional resistance of both ligation systems. Eighty stainless steel brackets were tested by sliding along straight lengths of 0.018 inch round and 0.019 x 0.025 inch rectangular stainless steel wires ligated with either conventional elastomerics or the Slide system (Leone, Florence, Italy). During the tests the brackets and wires were lubricated with artificial saliva. A specially constructed jig assembly was used to hold the bracket and archwire securely. The jig was clamped in an Instron universal load testing machine. Crosshead speed was controlled via a microcomputer connected to the Instron machine. The static frictional forces at 0 degree bracket/wire angulation were measured for both systems, fresh from the pack and after storage in artificial saliva at 37 degrees C for 24 hours. The results of this investigation demonstrated that the Slide ligatures produced significantly lower static frictional resistance than conventional elastomeric modules in the fresh condition and after 24 hours of storage in a simulated oral environment (p static frictional resistance of conventional elastomeric modules and the Slide system (p = 0.525). The claim by the manufacturer that the Slide system produces lower frictional resistance than conventional elastomeric modules is upheld.

Addressing maternal healthcare through demand side financial incentives: experience of Janani Suraksha Yojana program in India.

Science.gov (United States)

Gopalan, Saji S; Durairaj, Varatharajan

2012-09-15

Demand side financing (DSF) is a widely employed strategy to enhance utilization of healthcare. The impact of DSF on health care seeking in general and that of maternal care in particular is already known. Yet, its effect on financial access to care, out-of-pocket spending (OOPS) and provider motivations is not considerably established. Without such evidence, DSFs may not be recommendable to build up any sustainable healthcare delivery approach. This study explores the above aspects on India's Janani Suraksha Yojana (JSY) program. This study employed design and was conducted in three districts of Orissa, selected through a three-stage stratified sampling. The quantitative method was used to review the Health Management Information System (HMIS). The qualitative methods included focus groups discussions with beneficiaries (n = 19) and community intermediaries (n = 9), and interviews (n = 7) with Ministry of Health officials. HMIS data enabled to review maternal healthcare utilization. Group discussions and interviews explored the perceived impact of JSY on in-facility delivery, OOPS, healthcare costs, quality of care and performance motivation of community health workers. The number of institutional deliveries, ante-and post-natal care visits increased after the introduction of JSY with an annual net growth of 18.1%, 3.6% and 5% respectively. The financial incentive provided partial financial risk-protection as it could cover only 25.5% of the maternal healthcare cost of the beneficiaries in rural areas and 14.3% in urban areas. The incentive induced fresh out-of-pocket spending for some mothers and it could not address maternal care requirements comprehensively. An activity-based community worker model was encouraging to augment maternal healthcare consumption. However, the existing level of financial incentives and systemic support were inadequate to motivate the volunteers optimally on their performance. Demand side financial incentive could enhance financial

Reflections on Friction in Quantum Mechanics

Directory of Open Access Journals (Sweden)

Yair Rezek

2010-08-01

Full Text Available Distinctly quantum friction effects of three types are surveyed: internalfriction, measurement-induced friction, and quantum-fluctuation-induced friction. We demonstrate that external driving will lead to quantum internal friction, and critique the measurement-based interpretation of friction. We conclude that in general systems will experience internal and external quantum friction over and beyond the classical frictional contributions.

Nano-friction behavior of phosphorene.

Science.gov (United States)

Bai, Lichun; Liu, Bo; Srikanth, Narasimalu; Tian, Yu; Zhou, Kun

2017-09-01

Nano-friction of phosphorene plays a significant role in affecting the controllability and efficiency of applying strain engineering to tune its properties. So far, the friction behavior of phosphorene has not been studied. This work studies the friction of single-layer and bilayer phosphorene on an amorphous silicon substrate by sliding a rigid tip. For the single-layer phosphorene, it is found that its friction is highly anisotropic, i.e. the friction is larger along the armchair direction than that along the zigzag direction. Moreover, pre-strain of the phosphorene also exhibits anisotropic effects. The friction increases with the pre-strain along the zigzag direction, but decreases with that along the armchair direction. Furthermore, the strong adhesion between the phosphorene and its substrate increases the friction between the phosphorene and the tip. For bilayer phosphorene, its friction highly depends on its stacking mode, which determines the contact interface with a commensurate or incommensurate pattern. This friction behavior is quite unique and greatly differs from that of graphene and molybdenum disulfide. Detailed analysis reveals that this behavior results from the combination effect of the friction contact area, the potential-energy profile of phosphorene, and its unique elongation.

Frictional Heating with Time-Dependent Specific Power of Friction

Directory of Open Access Journals (Sweden)

Topczewska Katarzyna

2017-06-01

Full Text Available In this paper analytical solutions of the thermal problems of friction were received. The appropriate boundary-value problems of heat conduction were formulated and solved for a homogeneous semi–space (a brake disc heated on its free surface by frictional heat fluxes with different and time-dependent intensities. Solutions were obtained in dimensionless form using Duhamel's theorem. Based on received solutions, evolution and spatial distribution of the dimensionless temperature were analyzed using numerical methods. The numerical results allowed to determine influence of the time distribution of friction power on the spatio-temporal temperature distribution in brake disc.

Utility Sector Impacts of Reduced Electricity Demand

Energy Technology Data Exchange (ETDEWEB)

Coughlin, Katie

2014-12-01

This report presents a new approach to estimating the marginal utility sector impacts associated with electricity demand reductions. The method uses publicly available data and provides results in the form of time series of impact factors. The input data are taken from the Energy Information Agency's Annual Energy Outlook (AEO) projections of how the electric system might evolve in the reference case, and in a number of side cases that incorporate different effciency and other policy assumptions. The data published with the AEO are used to define quantitative relationships between demand-side electricity reductions by end use and supply-side changes to capacity by plant type, generation by fuel type and emissions of CO2, Hg, NOx and SO2. The impact factors define the change in each of these quantities per unit reduction in site electricity demand. We find that the relative variation in these impacts by end use is small, but the time variation can be significant.

High speed friction microscopy and nanoscale friction coefficient mapping

International Nuclear Information System (INIS)

Bosse, James L; Lee, Sungjun; Huey, Bryan D; Andersen, Andreas Sø; Sutherland, Duncan S

2014-01-01

As mechanical devices in the nano/micro length scale are increasingly employed, it is crucial to understand nanoscale friction and wear especially at technically relevant sliding velocities. Accordingly, a novel technique has been developed for friction coefficient mapping (FCM), leveraging recent advances in high speed AFM. The technique efficiently acquires friction versus force curves based on a sequence of images at a single location, each with incrementally lower loads. As a result, true maps of the coefficient of friction can be uniquely calculated for heterogeneous surfaces. These parameters are determined at a scan velocity as fast as 2 mm s −1 for microfabricated SiO 2 mesas and Au coated pits, yielding results that are identical to traditional speed measurements despite being ∼1000 times faster. To demonstrate the upper limit of sliding velocity for the custom setup, the friction properties of mica are reported from 200 µm s −1 up to 2 cm s −1 . While FCM is applicable to any AFM and scanning speed, quantitative nanotribology investigations of heterogeneous sliding or rolling components are therefore uniquely possible, even at realistic velocities for devices such as MEMS, biological implants, or data storage systems. (paper)

Analysis of the Journal Bearing Friction Losses in a Heavy-Duty Diesel Engine

Directory of Open Access Journals (Sweden)

Christoph Knauder

2015-04-01

Full Text Available Internal combustion engines (ICE for the use in heavy-duty trucks and buses have to fulfil demanding requirements for both vehicle efficiency as well as for emission of greenhouse gases. Beside the piston assembly the journal bearings are among the largest contributors to friction in the ICE. Through a combination of measurements and validated simulation methods the journal bearing friction losses of a state-of-the-art heavy-duty Diesel engine are investigated for a large range of real world operating conditions. To this task recently developed and extensively validated simulation methods are used together with realistic lubricant models that consider the Non-Newtonian behaviour as well as the piezoviscous effect. In addition, the potential for further friction reduction with the use of ultra-low viscosity lubricants is explored. The results reveal a potential of about 8% friction reduction in the journal bearings using a 0W20 ultra-low viscosity oil with an HTHS-viscosity (The HTHS-viscosity is defined as the dynamic viscosity of the lubricant measured at 150 °C and at a shear rate of 106 s

Frictional behaviour of high performance fibrous tows: Friction experiments

NARCIS (Netherlands)

Cornelissen, Bo; Rietman, Bert; Akkerman, Remko

2013-01-01

Tow friction is an important mechanism in the production and processing of high performance fibrous tows. The frictional behaviour of these tows is anisotropic due to the texture of the filaments as well as the tows. This work describes capstan experiments that were performed to measure the

Electric power market liberalization and demand-side management (DSM); Denryoku shijo jiyuka to DSM

Energy Technology Data Exchange (ETDEWEB)

Yajima, M. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

1997-01-30

This paper explains effects of market liberalization which will lead to introducing competition in electric power business on demand-side management (DSM), by quoting examples mainly in the United States. The paper also describes the future outlook thereon. The DSM program in the United States has expanded for the period between 1989 through 1994. However, during the last few years, the movements of electric power market liberalization have come to force electric power business entities to change their management strategies and reduction in expense. This situation has resulted in reduction in the DSM budget. Future DSM programs are thought to diversify into the following types: a program such as load management which has effect of reducing expenses and investments in investment time periods of 5 to 10 years, a program effective for users such as high-efficiency motors which have effects of reducing expenses and improving efficiency in investment time periods of 3 to 5 years, a program which will be effective enough if market barriers are removed after the market conversions, but requires subsidies and purchase guarantees, and a social program intended for environmental effects and low-income users. 4 refs., 1 tab.

Protecting the radiation-damaged skin from friction: a mini review

International Nuclear Information System (INIS)

Herst, Patries M

2014-01-01

Radiation-induced skin reactions are an unavoidable side effect of external beam radiation therapy, particularly in areas prone to friction and excess moisture such as the axilla, head and neck region, perineum and skin folds. Clinical studies investigating interventions for preventing or managing these reactions have largely focussed on formulations with moisturising, anti-inflammatory, anti-microbial and wound healing properties. However, none of these interventions has emerged as a consistent candidate for best practice. Much less emphasis has been placed on evaluating ways to protect the radiation-damaged skin from friction and excess moisture. This mini review analyses the clinical evidence for barrier products that form a protective layer by adhering very closely to the skin folds and do not cause further trauma to the radiation-damaged skin upon removal. A database search identified only two types of barrier products that fitted these criteria and these were tested in two case series and six controlled clinical trials. Friction protection was most effective when the interventions were used from the start of treatment and continued for several weeks after completion of treatment. Soft silicone dressings (Mepilex Lite and Mepitel Film) and Cavilon No Sting Barrier Film, but not Cavilon Moisturizing Barrier Cream, decreased skin reaction severity, most likely due to differences in formulation and skin build-up properties. It seems that prophylactic use of friction protection of areas at risk could be a worthwhile addition to routine care of radiation-damaged skin

Effect of Process Parameters on Friction Model in Computer Simulation of Linear Friction Welding

Directory of Open Access Journals (Sweden)

A. Yamileva

2014-07-01

Full Text Available The friction model is important part of a numerical model of linear friction welding. Its selection determines the accuracy of the results. Existing models employ the classical law of Amonton-Coulomb where the friction coefficient is either constant or linearly dependent on a single parameter. Determination of the coefficient of friction is a time consuming process that requires a lot of experiments. So the feasibility of determinating the complex dependence should be assessing by analysis of effect of approximating law for friction model on simulation results.

A Hybrid Genetic Wind Driven Heuristic Optimization Algorithm for Demand Side Management in Smart Grid

Directory of Open Access Journals (Sweden)

Nadeem Javaid

2017-03-01

Full Text Available In recent years, demand side management (DSM techniques have been designed for residential, industrial and commercial sectors. These techniques are very effective in flattening the load profile of customers in grid area networks. In this paper, a heuristic algorithms-based energy management controller is designed for a residential area in a smart grid. In essence, five heuristic algorithms (the genetic algorithm (GA, the binary particle swarm optimization (BPSO algorithm, the bacterial foraging optimization algorithm (BFOA, the wind-driven optimization (WDO algorithm and our proposed hybrid genetic wind-driven (GWD algorithm are evaluated. These algorithms are used for scheduling residential loads between peak hours (PHs and off-peak hours (OPHs in a real-time pricing (RTP environment while maximizing user comfort (UC and minimizing both electricity cost and the peak to average ratio (PAR. Moreover, these algorithms are tested in two scenarios: (i scheduling the load of a single home and (ii scheduling the load of multiple homes. Simulation results show that our proposed hybrid GWD algorithm performs better than the other heuristic algorithms in terms of the selected performance metrics.

Friction-induced Vibrations in an Experimental Drill-string System for Various Friction Situations

NARCIS (Netherlands)

Mihajlovic, N.; Wouw, van de N.; Hendriks, M.P.M.; Nijmeijer, H.

2005-01-01

Friction-induced limit cycling deteriorates system performance in a wide variety of mechanical systems. In this paper, we study the way in which essential friction characteristics affect the occurrence and nature of friction-induced limit cycling in flexible rotor systems. This study is performed on

Investigation of Microstructure and Microhardness in Self-Reacting Friction Stir Welded AA2014-T6 and AA2219-T87

Science.gov (United States)

Horton, K. Renee; McGill, Preston; Barkey, Mark

2011-01-01

Friction stir welding (FSW) is a solid state welding process with potential advantages for aerospace and automotive industries dealing with light alloys. Self-reacting friction stir welding (SR-FSW) is one variation of the FSW process being developed at the National Aeronautics and Space Administration (NASA) for use in the fabrication of propellant tanks. This work reports on the microstructure and microhardness of SR-FSW between two dissimilar aluminum alloys. Specifically, the study examines the cross section of the weld joint formed between an AA2014-T6 plate on the advancing side and an AA2219-T87 plate on the retreating side. The microstructural analysis shows an irregularly displaced weld seam from the advancing side past the thermo-mechanical affected zone (TMAZ) into the weld nugget region. There are sharp variations in the microhardness across the weld. These variations are described in the paper and mechanisms for their formation are discussed.

Application of dGNSS in Alpine Ski Racing: Basis for Evaluating Physical Demands and Safety

Science.gov (United States)

Gilgien, Matthias; Kröll, Josef; Spörri, Jörg; Crivelli, Philip; Müller, Erich

2018-01-01

External forces, such as ground reaction force or air drag acting on athletes' bodies in sports, determine the sport-specific demands on athletes' physical fitness. In order to establish appropriate physical conditioning regimes, which adequately prepare athletes for the loads and physical demands occurring in their sports and help reduce the risk of injury, sport-and/or discipline-specific knowledge of the external forces is needed. However, due to methodological shortcomings in biomechanical research, data comprehensively describing the external forces that occur in alpine super-G (SG) and downhill (DH) are so far lacking. Therefore, this study applied new and accurate wearable sensor-based technology to determine the external forces acting on skiers during World Cup (WC) alpine skiing competitions in the disciplines of SG and DH and to compare these with those occurring in giant slalom (GS), for which previous research knowledge exists. External forces were determined using WC forerunners carrying a differential global navigation satellite system (dGNSS). Combining the dGNSS data with a digital terrain model of the snow surface and an air drag model, the magnitudes of ground reaction forces were computed. It was found that the applied methodology may not only be used to track physical demands and loads on athletes, but also to simultaneously investigate safety aspects, such as the effectiveness of speed control through increased air drag and ski–snow friction forces in the respective disciplines. Therefore, the component of the ground reaction force in the direction of travel (ski–snow friction) and air drag force were computed. This study showed that (1) the validity of high-end dGNSS systems allows meaningful investigations such as characterization of physical demands and effectiveness of safety measures in highly dynamic sports; (2) physical demands were substantially different between GS, SG, and DH; and (3) safety-related reduction of skiing speed might

Application of dGNSS in Alpine Ski Racing: Basis for Evaluating Physical Demands and Safety

Directory of Open Access Journals (Sweden)

Matthias Gilgien

2018-03-01

Full Text Available External forces, such as ground reaction force or air drag acting on athletes' bodies in sports, determine the sport-specific demands on athletes' physical fitness. In order to establish appropriate physical conditioning regimes, which adequately prepare athletes for the loads and physical demands occurring in their sports and help reduce the risk of injury, sport-and/or discipline-specific knowledge of the external forces is needed. However, due to methodological shortcomings in biomechanical research, data comprehensively describing the external forces that occur in alpine super-G (SG and downhill (DH are so far lacking. Therefore, this study applied new and accurate wearable sensor-based technology to determine the external forces acting on skiers during World Cup (WC alpine skiing competitions in the disciplines of SG and DH and to compare these with those occurring in giant slalom (GS, for which previous research knowledge exists. External forces were determined using WC forerunners carrying a differential global navigation satellite system (dGNSS. Combining the dGNSS data with a digital terrain model of the snow surface and an air drag model, the magnitudes of ground reaction forces were computed. It was found that the applied methodology may not only be used to track physical demands and loads on athletes, but also to simultaneously investigate safety aspects, such as the effectiveness of speed control through increased air drag and ski–snow friction forces in the respective disciplines. Therefore, the component of the ground reaction force in the direction of travel (ski–snow friction and air drag force were computed. This study showed that (1 the validity of high-end dGNSS systems allows meaningful investigations such as characterization of physical demands and effectiveness of safety measures in highly dynamic sports; (2 physical demands were substantially different between GS, SG, and DH; and (3 safety-related reduction of skiing

Application of dGNSS in Alpine Ski Racing: Basis for Evaluating Physical Demands and Safety.

Science.gov (United States)

Gilgien, Matthias; Kröll, Josef; Spörri, Jörg; Crivelli, Philip; Müller, Erich

2018-01-01

External forces, such as ground reaction force or air drag acting on athletes' bodies in sports, determine the sport-specific demands on athletes' physical fitness. In order to establish appropriate physical conditioning regimes, which adequately prepare athletes for the loads and physical demands occurring in their sports and help reduce the risk of injury, sport-and/or discipline-specific knowledge of the external forces is needed. However, due to methodological shortcomings in biomechanical research, data comprehensively describing the external forces that occur in alpine super-G (SG) and downhill (DH) are so far lacking. Therefore, this study applied new and accurate wearable sensor-based technology to determine the external forces acting on skiers during World Cup (WC) alpine skiing competitions in the disciplines of SG and DH and to compare these with those occurring in giant slalom (GS), for which previous research knowledge exists. External forces were determined using WC forerunners carrying a differential global navigation satellite system (dGNSS). Combining the dGNSS data with a digital terrain model of the snow surface and an air drag model, the magnitudes of ground reaction forces were computed. It was found that the applied methodology may not only be used to track physical demands and loads on athletes, but also to simultaneously investigate safety aspects, such as the effectiveness of speed control through increased air drag and ski-snow friction forces in the respective disciplines. Therefore, the component of the ground reaction force in the direction of travel (ski-snow friction) and air drag force were computed. This study showed that (1) the validity of high-end dGNSS systems allows meaningful investigations such as characterization of physical demands and effectiveness of safety measures in highly dynamic sports; (2) physical demands were substantially different between GS, SG, and DH; and (3) safety-related reduction of skiing speed might be

Modelling of demand response and market power

International Nuclear Information System (INIS)

Kristoffersen, B.B.; Donslund, B.; Boerre Eriksen, P.

2004-01-01

Demand-side flexibility and demand response to high prices are prerequisites for the proper functioning of the Nordic power market. If the consumers are unwilling to respond to high prices, the market may fail the clearing, and this may result in unwanted forced demand disconnections. Being the TSO of Western Denmark, Eltra is responsible of both security of supply and the design of the power market within its area. On this basis, Eltra has developed a new mathematical model tool for analysing the Nordic wholesale market. The model is named MARS (MARket Simulation). The model is able to handle hydropower and thermal production, nuclear power and wind power. Production, demand and exchanges modelled on an hourly basis are new important features of the model. The model uses the same principles as Nord Pool (The Nordic Power Exchange), including the division of the Nordic countries into price areas. On the demand side, price elasticity is taken into account and described by a Cobb-Douglas function. Apart from simulating perfect competition markets, particular attention has been given to modelling imperfect market conditions, i.e. exercise of market power on the supply side. Market power is simulated by using game theory, including the Nash equilibrium concept. The paper gives a short description of the MARS model. Besides, focus is on the application of the model in order to illustrate the importance of demand response in the Nordic market. Simulations with different values of demand elasticity are compared. Calculations are carried out for perfect competition and for the situation in which market power is exercised by the large power producers in the Nordic countries (oligopoly). (au)

Micromechanical study of macroscopic friction and dissipation in idealised granular materials: the effect of interparticle friction

NARCIS (Netherlands)

Kruyt, Nicolaas P.; Gutkowski, Witold; Rothenburg, L.; Kowalewski, Tomasz A.

2004-01-01

Using Discrete Element Method (DEM) simulations with varying interparticle friction coefficient, the relation between interparticle friction coefficient and macroscopic continuum friction and dissipation is investigated. As expected, macroscopic friction and dilatancy increase with interparticle

An analysis of the factors influencing demand-side management activity in the electric utility industry

Science.gov (United States)

Bock, Mark Joseph

Demand-side management (DSM), defined as the "planning, implementation, and monitoring of utility activities designed to encourage consumers to modify their pattern of electricity usage, including the timing and level of electricity demand," is a relatively new concept in the U.S. electric power industry. Nevertheless, in twenty years since it was first introduced, utility expenditures on DSM programs, as well as the number of such programs, have grown rapidly. At first glance, it may seem peculiar that a firm would actively attempt to reduce demand for its primary product. There are two primary explanations as to why a utility might pursue DSM: regulatory mandate, and self-interest. The purpose of this dissertation is to determine the impact these influences have on the amount of DSM undertaken by utilities. This research is important for two reasons. First, it provides insight into whether DSM will continue to exist as competition becomes more prevalent in the industry. Secondly, it is important because no one has taken a comprehensive look at firm-level DSM activity on an industry-wide basis. The primary data set used in this dissertation is the U.S. Department of Energy's Annual Electric Utility Report, Form EIA-861, which represents the most comprehensive data set available for analyzing DSM activity in the U.S. There are four measures of DSM activity in this data set: (1) utility expenditures on DSM programs; (2) energy savings by DSM program participants; and (3) the actual and (4) the potential reductions in peak load resulting from utility DSM measures. Each is used as the dependent variable in an econometric analysis where independent variables include various utility characteristics, regulatory characteristics, and service territory and customer characteristics. In general, the results from the econometric analysis suggest that in 1993, DSM activity was primarily the result of regulatory pressure. All of the evidence suggests that if DSM continues to

Science 101: What Causes Friction?

Science.gov (United States)

Robertson, Bill

2014-01-01

Defining friction and asking what causes it might seem like a trivial question. Friction seems simple enough to understand. Friction is a force between surfaces that pushes against things that are moving or tending to move, and the rougher the surfaces, the greater the friction. Bill Robertson answers this by saying, "Well, not exactly".…

Hawaii demand-side management resource assessment. Final report, Reference Volume 3 -- Residential and commercial sector DSM analyses: Detailed results from the DBEDT DSM assessment model; Part 1, Technical potential

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-04-01

The Hawaii Demand-Side Management Resource Assessment was the fourth of seven projects in the Hawaii Energy Strategy (HES) program. HES was designed by the Department of Business, Economic Development, and Tourism (DBEDT) to produce an integrated energy strategy for the State of Hawaii. The purpose of Project 4 was to develop a comprehensive assessment of Hawaii`s demand-side management (DSM) resources. To meet this objective, the project was divided into two phases. The first phase included development of a DSM technology database and the identification of Hawaii commercial building characteristics through on-site audits. These Phase 1 products were then used in Phase 2 to identify expected energy impacts from DSM measures in typical residential and commercial buildings in Hawaii. The building energy simulation model DOE-2.1E was utilized to identify the DSM energy impacts. More detailed information on the typical buildings and the DOE-2.1E modeling effort is available in Reference Volume 1, ``Building Prototype Analysis``. In addition to the DOE-2.1E analysis, estimates of residential and commercial sector gas and electric DSM potential for the four counties of Honolulu, Hawaii, Maui, and Kauai through 2014 were forecasted by the new DBEDT DSM Assessment Model. Results from DBEDTs energy forecasting model, ENERGY 2020, were linked with results from DOE-2.1E building energy simulation runs and estimates of DSM measure impacts, costs, lifetime, and anticipated market penetration rates in the DBEDT DSM Model. Through its algorithms, estimates of DSM potential for each forecast year were developed. Using the load shape information from the DOE-2.1E simulation runs, estimates of electric peak demand impacts were developed. Numerous tables and figures illustrating the technical potential for demand-side management are included.

Novel Friction Law for the Static Friction Force based on Local Precursor Slipping

OpenAIRE

Katano, Yu; Nakano, Ken; Otsuki, Michio; Matsukawa, Hiroshi

2014-01-01

The sliding of a solid object on a solid substrate requires a shear force that is larger than the maximum static friction force. It is commonly believed that the maximum static friction force is proportional to the loading force and does not depend on the apparent contact area. The ratio of the maximum static friction force to the loading force is called the static friction coefficient µ M, which is considered to be a constant. Here, we conduct experiments demonstrating that the static fricti...

Contact compliance effects in the frictional response of bioinspired fibrillar adhesives

Science.gov (United States)

Piccardo, Marco; Chateauminois, Antoine; Fretigny, Christian; Pugno, Nicola M.; Sitti, Metin

2013-01-01

The shear failure and friction mechanisms of bioinspired adhesives consisting of elastomer arrays of microfibres terminated by mushroom-shaped tips are investigated in contact with a rigid lens. In order to reveal the interplay between the vertical and lateral loading directions, experiments are carried out using a custom friction set-up in which normal stiffness can be made either high or low when compared with the stiffness of the contact between the fibrillar adhesive and the lens. Using in situ contact imaging, the shear failure of the adhesive is found to involve two successive mechanisms: (i) cavitation and peeling at the contact interface between the mushroom-shaped fibre tip endings and the lens; and (ii) side re-adhesion of the fibre's stem to the lens. The extent of these mechanisms and their implications regarding static friction forces is found to depend on the crosstalk between the normal and lateral loading directions that can result in contact instabilities associated with fibre buckling. In addition, the effects of the viscoelastic behaviour of the polyurethane material on the rate dependence of the shear response of the adhesive are accounted for. PMID:23554349

Demand Response Spinning Reserve Demonstration

Energy Technology Data Exchange (ETDEWEB)

Eto, Joseph H.; Nelson-Hoffman, Janine; Torres, Carlos; Hirth,Scott; Yinger, Bob; Kueck, John; Kirby, Brendan; Bernier, Clark; Wright,Roger; Barat, A.; Watson, David S.

2007-05-01

The Demand Response Spinning Reserve project is a pioneeringdemonstration of how existing utility load-management assets can providean important electricity system reliability resource known as spinningreserve. Using aggregated demand-side resources to provide spinningreserve will give grid operators at the California Independent SystemOperator (CAISO) and Southern California Edison (SCE) a powerful, newtool to improve system reliability, prevent rolling blackouts, and lowersystem operating costs.

Balancing supply and demand resources

International Nuclear Information System (INIS)

Sinha, J.; Saleeby, R.G.

1990-01-01

This article deals with using demand-side management (DSM) resources as an effective means of balancing supply and demand as a part of least-cost planning. The authors present a more sophisticated application of the load forecast adjustment method that reduces the number of DSM programs that need to be evaluated and provides blocks large enough to eliminate resolution problems in production costing models

Kalker's algorithm Fastsim solves tangential contact problems with slip-dependent friction and friction anisotropy

Science.gov (United States)

Piotrowski, J.

2010-07-01

This paper presents two extensions of Kalker's algorithm Fastsim of the simplified theory of rolling contact. The first extension is for solving tangential contact problems with the coefficient of friction depending on slip velocity. Two friction laws have been considered: with and without recuperation of the static friction. According to the tribological hypothesis for metallic bodies shear failure, the friction law without recuperation of static friction is more suitable for wheel and rail than the other one. Sample results present local quantities inside the contact area (division to slip and adhesion, traction) as well as global ones (creep forces as functions of creepages and rolling velocity). For the coefficient of friction diminishing with slip, the creep forces decay after reaching the maximum and they depend on the rolling velocity. The second extension is for solving tangential contact problems with friction anisotropy characterised by a convex set of the permissible tangential tractions. The effect of the anisotropy has been shown on examples of rolling without spin and in the presence of pure spin for the elliptical set. The friction anisotropy influences tangential tractions and creep forces. Sample results present local and global quantities. Both extensions have been described with the same language of formulation and they may be merged into one, joint algorithm.

Dependence of frictional strength on compositional variations of Hayward fault rock gouges

Science.gov (United States)

Morrow, Carolyn A.; Moore, Diane E.; Lockner, David A.

2010-01-01

The northern termination of the locked portion of the Hayward Fault near Berkeley, California, is found to coincide with the transition from strong Franciscan metagraywacke to melange on the western side of the fault. Both of these units are juxtaposed with various serpentinite, gabbro and graywacke units to the east, suggesting that the gouges formed within the Hayward Fault zone may vary widely due to the mixing of adjacent rock units and that the mechanical behavior of the fault would be best modeled by determining the frictional properties of mixtures of the principal rock types. To this end, room temperature, water-saturated, triaxial shearing tests were conducted on binary and ternary mixtures of fine-grained gouges prepared from serpentinite and gabbro from the Coast Range Ophiolite, a Great Valley Sequence graywacke, and three different Franciscan Complex metasedimentary rocks. Friction coefficients ranged from 0.36 for the serpentinite to 0.84 for the gabbro, with four of the rock types having coefficients of friction ranging from 0.67-0.84. The friction coefficients of the mixtures can be predicted reliably by a simple weighted average of the end-member dry-weight percentages and strengths for all samples except those containing serpentinite. For the serpentinite mixtures, a linear trend between end-member values slightly overestimates the coefficients of friction in the midcomposition ranges. The range in strength for these rock admixtures suggests that both theoretical and numerical modeling of the fault should attempt to account for variations in rock and gouge properties.

Bayesian Analysis of Demand Elasticity in the Italian Electricity Market

Directory of Open Access Journals (Sweden)

Maria Chiara D'Errico

2015-09-01

Full Text Available The liberalization of the Italian electricity market is a decade old. Within these last ten years, the supply side has been extensively analyzed, but not the demand side. The aim of this paper is to provide a new method for estimation of the demand elasticity, based on Bayesian methods applied to the Italian electricity market. We used individual demand bids data in the day-ahead market in the Italian Power Exchange (IPEX, for 2011, in order to construct an aggregate demand function at the hourly level. We took into account the existence of both elastic and inelastic bidders on the demand side. The empirical results show that elasticity varies significantly during the day and across periods of the year. In addition, the elasticity hourly distribution is clearly skewed and more so in the daily hours. The Bayesian method is a useful tool for policy-making, insofar as the regulator can start with a priori historical information on market behavior and estimate actual market outcomes in response to new policy actions.

Addressing maternal healthcare through demand side financial incentives: experience of Janani Suraksha Yojana program in India

Directory of Open Access Journals (Sweden)

Gopalan Saji S

2012-09-01

Full Text Available Abstract Background Demand side financing (DSF is a widely employed strategy to enhance utilization of healthcare. The impact of DSF on health care seeking in general and that of maternal care in particular is already known. Yet, its effect on financial access to care, out-of-pocket spending (OOPS and provider motivations is not considerably established. Without such evidence, DSFs may not be recommendable to build up any sustainable healthcare delivery approach. This study explores the above aspects on India’s Janani Suraksha Yojana (JSY program. Methods This study employed design and was conducted in three districts of Orissa, selected through a three-stage stratified sampling. The quantitative method was used to review the Health Management Information System (HMIS. The qualitative methods included focus groups discussions with beneficiaries (n = 19 and community intermediaries (n = 9, and interviews (n = 7 with Ministry of Health officials. HMIS data enabled to review maternal healthcare utilization. Group discussions and interviews explored the perceived impact of JSY on in-facility delivery, OOPS, healthcare costs, quality of care and performance motivation of community health workers. Results The number of institutional deliveries, ante-and post-natal care visits increased after the introduction of JSY with an annual net growth of 18.1%, 3.6% and 5% respectively. The financial incentive provided partial financial risk-protection as it could cover only 25.5% of the maternal healthcare cost of the beneficiaries in rural areas and 14.3% in urban areas. The incentive induced fresh out-of-pocket spending for some mothers and it could not address maternal care requirements comprehensively. An activity-based community worker model was encouraging to augment maternal healthcare consumption. However, the existing level of financial incentives and systemic support were inadequate to motivate the volunteers optimally on their

A numerical study of the rolling friction between a microsphere and a substrate considering the adhesive effect

International Nuclear Information System (INIS)

Zhang, Yuyan; Wang, Xiaoli; Yang, Weixu; Li, Hanqing

2016-01-01

A numerical model of the rolling friction between a microsphere and a substrate is established by introducing the adhesion hysteresis between the front and rear sides of the contact region into Zhang’s adhesive contact model. Effects of the size ratio which is defined as the sphere radius divided by the equilibrium separation, relative amount of adhesion hysteresis and Tabor parameter on the dimensionless maximum rolling friction torque in the case of zero normal force are inspected, and the quantitative relationship between the maximum rolling friction torque and the normal force is achieved. Results indicate that due to adhesion hysteresis at microscale, the dimensionless maximum rolling friction torque at zero normal force is not zero, which not only increases with decreasing size ratio, showing clear size effects, but also increases with increasing relative amount of adhesion hysteresis and Tabor parameter. In addition, the maximum rolling friction torque at microscale presents a sublinear relationship with the normal force, and the exponent of the normal force is influenced by the size ratio, relative amount of adhesion hysteresis and Tabor parameter, which are remarkably different from the superlinear relationship at macroscale. (paper)

Orchestrating utility supply and demand in real-time via the Internet, home networks, and smart appliances

Energy Technology Data Exchange (ETDEWEB)

Cruickshank, R.F. III [Power Networks, Big Indian, NY (United States)

2008-07-01

This paper presented a model to illustrate the efficient coordination between the supply-side and demand-side of household electricity use and the magnitude of demand that can be managed using real-time pricing. In real-time supply and demand side management, a variable price for service is sent via Internet from the supply-side to the demand-side. The 3 benefits to this type of demand-side management are that traditional fossil-fuelled electrical capacity can operate less of the time and more efficiently; renewable electrical capacity such as wind and solar power can be put to use more efficiently when it becomes available; and additional means are available to protect the transmission and distribution infrastructure of the utility. A critical requirement is that pricing should change frequently throughout the day so that budget conscious consumers do not have to wait too long for favourable pricing to use their appliances. 12 refs., 9 figs.

Corrosion effects on friction factors

International Nuclear Information System (INIS)

Magleby, H.L.; Shaffer, S.J.

1996-01-01

This paper presents the results of NRC-sponsored material specimen tests that were performed to determine if corrosion increases the friction factors of sliding surfaces of motor-operated gate valves, which could require higher forces to close and open safety-related valves when subjected to their design basis differential pressures. Friction tests were performed with uncorroded specimens and specimens subjected to accelerated corrosion. Preliminary tests at ambient conditions showed that corrosion increased the friction factors, indicating the need for additional tests duplicating valve operating parameters at hot conditions. The additional tests showed friction factors of corroded specimens were 0.1 to 0.2 higher than for uncorroded specimens, and that the friction factors of the corroded specimens were not very dependent on contact stress or corrosion film thickness. The measured values of friction factors for the three corrosion films tested (simulating three operating times) were in the range of 0.3 to 0.4. The friction factor for even the shortest simulated operating time was essentially the same as the others, indicating that the friction factors appear to reach a plateau and that the plateau is reached quickly

A Danish Heat Atlas for Supply Strategies and Demand Side Management

DEFF Research Database (Denmark)

Möller, Bernd

The expansion of district heating, the assessment of the impact of heat supply strategies, as well as the analysis of significant heat demand savings require sound decision support at high detail. Data is needed to continuously quantify potentials and costs of measures in the end-use and supply...... heat demand and possible savings. The location of each building relative to heat supply technologies is mapped and used for the assessment of supply strategies by potentials, costs and environmental impact. Both elements can furthermore be used to balance investments in supply with investments...

Cooperative and submolecular dissipation mechanisms of sliding friction in complex organic systems.

Science.gov (United States)

Knorr, Daniel B; Gray, Tomoko O; Overney, René M

2008-08-21

Energy dissipation in single asperity sliding friction was directly linked to submolecular modes of mobility by intrinsic friction analysis, involving time-temperature superposition along with thermodynamic stress and reaction rate models. Thereby, polystyrene served as a representative tribological sample for organic and amorphous complex systems. This study reveals the significance of surface and subsurface (alpha-, beta-, and gamma-) relaxational modes, which couple under appropriate external conditions (load, temperature, and rate) with shear induced disturbances, and thus gives rise to material specific frictional dissipation. At low pressures and temperatures below the glass transition point, the phenyl pendant side groups of polystyrene, known for their preferential orientation at the free surface, were noticed to be the primary channel for dissipation of kinetic sliding-energy. While this process was found to be truly enthalpic (activation energy of 8 kcalmol), energy dissipation was shown to possess both enthalpic and cooperative entropic contributions above the loading capacity of the surface phenyl groups (9.9 kcalmol) or above the glass transition. Apparent Arrhenius activation energies of frictional dissipation of 22 and 90 kcalmol, respectively, and cooperative contributions up to 80% were found. As such, this study highlights issues critical to organic lubricant design, i.e., the intrinsic enthalpic activation barriers of mobile linker groups, the evaluation of cooperative mobility phenomena, and critical tribological parameters to access or avoid coupling between shear disturbances and molecular actuators.

Definitional-mission report: Demand-side management program for the Tenaga Nasional Berhad in Malaysia. Export trade information

Energy Technology Data Exchange (ETDEWEB)

1992-03-01

A definitional mission evaluated the prospects of the US Trade and Development Program (TDP) funding a market demonstration of a Demand Side Management (DSM) program being developed by the Tenaga Nasional Berhad (TNB) in Malaysia. TNB is the national electric utility of Malaysia with the responsibility to promote economically efficient supply of electricity needed for the economic development of Peninsular Malaysia. DSM is a utility-financed program to affect energy savings at the enduse level thereby reducing peak and base loads. Historically, TNB has taken the peak load and the load duration curves as given in planning and implementing the least-cost generation expansion strategy. It has refrained from influencing the pattern of energy use by the customer through any means other than tariff structures and levels. The experience of many utilities with DSM in the U.S. offers TNB an opportunity to develop a suitable DSM program for Malaysia.

Electric Boiler and Heat Pump Thermo-Electrical Models for Demand Side Management Analysis in Low Voltage Grids

DEFF Research Database (Denmark)

Diaz de Cerio Mendaza, Iker; Bak-Jensen, Birgitte; Chen, Zhe

2013-01-01

The last fifteen years many European countries have integrated large percentage of renewable energy on their electricity generation mix. In Denmark the 21.3% of the electricity consumed nowadays is produced by the wind, and it has planned to be the 50% by 2025. In order to front future challenges...... on the power system control and operation, created by this unstable way of generation, Demand Side Management turns to be a promising solution. The storage capacity from thermo-electric units, like electric boilers and heat pumps, allows operating them with certain freedom. Hence they can be employed under...... certain coordination, to actively respond to the power system fluctuations. The following paper presents two simple thermo-electrical models of an electrical boiler and an air-source CO2 heat pump system. The purpose is using them in low voltage grids analysis to assess their capacity and flexibility...

Energy Refurbishment of an Office Building with Hybrid Photovoltaic System and Demand-Side Management

Directory of Open Access Journals (Sweden)

Giovani Almeida Dávi

2017-08-01

Full Text Available On-site photovoltaic (PV and battery systems intend to improve buildings energy performance, however battery costs and monetary incentives are a major drawback for the introduction of these technologies into the electricity grids. This paper proposes an energy refurbishment of an office building based on multi-objective simulations. An innovative demand-side management approach is analyzed through the PV and battery control with the purpose of reducing grid power peaks and grid imported energy, as well as improving the project economy. Optimization results of load matching and grid interaction parameters, complemented with an economic analysis, are investigated in different scenarios. By means of battery use, the equivalent use of the grid connection is reduced by 12%, enhancing the grid interaction potential, and 10% of load matching rates can be increased. Project improvements indicate the grid connection capacity can be reduced by 13% and significant savings of up to 48% are achieved on yearly bills. The economy demonstrates the grid parity is only achieved for battery costs below 100 €/kWh and the payback period is large: 28 years. In the case with only PV system, the grid parity achieves better outcomes and the payback time is reduced by a half, making this a more attractive option.

Origins of Rolling Friction

Science.gov (United States)

Cross, Rod

2017-01-01

When a hard object rolls on a soft surface, or vice versa, rolling friction arises from deformation of the soft object or the soft surface. The friction force can be described in terms of an offset in the normal reaction force or in terms of energy loss arising from the deformation. The origin of the friction force itself is not entirely clear. It…

Multiple policies to enhance prescribing efficiency for established medicines in Europe with a particular focus on demand-side measures: findings and future implications

Directory of Open Access Journals (Sweden)

Brian eGodman

2014-06-01

Full Text Available Introduction: The appreciable growth in pharmaceutical expenditure has resulted in multiple initiatives across Europe to lower generic prices and enhance their utilisation. However, considerable variation in their use and prices. Objective: Assess the influence of multiple supply and demand-side initiatives across Europe for established medicines to enhance prescribing efficiency before a decision to prescribe a particular medicine. Subsequently utilise the findings to suggest potential future initiatives that countries could consider. Method: Analysis of different methodologies involving cross national and single country retrospective observational studies on reimbursed use and expenditure of PPIs, statins and renin-angiotensin inhibitor drugs among European countries. Results: Nature and intensity of the various initiatives appreciably influenced prescribing behaviour and expenditure, e.g. multiple measures resulted in reimbursed expenditure for PPIs in Scotland in 2010 56% below 2001 levels despite a 3 fold increase in utilisation and in the Netherlands, PPI expenditure fell by 58% in 2010 vs. 2000 despite a 3-fold increase in utilisation. A similarly picture was seen with prescribing restrictions, i.e. (i more aggressive follow-up of prescribing restrictions for patented statins and ARBs resulted in a greater reduction in the utilisation of patented statins in Austria vs. Norway and lower utilisation of patented ARBs vs. generic ACEIs in Croatia than Austria. However, limited impact of restrictions on esomeprazole in Norway with the first prescription or recommendation in hospital where restrictions do not apply. Similar findings when generic losartan became available in Western Europe. Conclusions: Multiple demand-side measures are needed to influence prescribing patterns. When combined with supply-side measures, activities can realise appreciable savings. Health authorities cannot rely on a ‘spill over’ effect between classes to affect

Subnanometer Resolution and Enhanced Friction Contrast at the Surface of Perylene Diimide PDI8-CN2 Thin Films in Ambient Conditions.

Science.gov (United States)

Buzio, Renato; Gerbi, Andrea; Barra, Mario; Chiarella, Fabio; Gnecco, Enrico; Cassinese, Antonio

2018-03-13

We report high-resolution surface morphology and friction force maps of polycrystalline organic thin films derived by deposition of the n-type perylene diimide semiconductor PDI8-CN 2 . We show that the in-plane molecular arrangement into ordered, cofacial slip-stacked rows results in a largely anisotropic surface structure, with a characteristic sawtooth corrugation of a few Ångstroms wavelength and height. Load-controlled experiments reveal different types of friction contrast between the alternating sloped and stepped regions, with transitions from atomic-scale dissipative stick-slip to smooth sliding with ultralow friction within the surface unit cell. Notably, such a rich phenomenology is captured under ambient conditions. We demonstrate that friction contrast is well reproduced by numerical simulations assuming a reduced corrugation of the tip-molecule potential nearby the step edges. We propose that the side alkyl chains pack into a compact low-surface-energy overlayer, and friction modulation reflects periodic heterogeneity of chains bending properties and subsurface anchoring to the perylene cores.

Microstructural Evolution and Fracture Behavior of Friction-Stir-Welded Al-Cu Laminated Composites

Science.gov (United States)

Beygi, R.; Kazeminezhad, Mohsen; Kokabi, A. H.

2014-01-01

In this study, we attempt to characterize the microstructural evolution during friction stir butt welding of Al-Cu-laminated composites and its effect on the fracture behavior of the joint. Emphasis is on the material flow and particle distribution in the stir zone. For this purpose, optical microscopy and scanning electron microscopy (SEM) images, energy-dispersive spectroscopy EDS and XRD analyses, hardness measurements, and tensile tests are carried out on the joints. It is shown that intermetallic compounds exist in lamellas of banding structure formed in the advancing side of the welds. In samples welded from the Cu side, the banding structure in the advancing side and the hook formation in the retreating side determine the fracture behavior of the joint. In samples welded from the Al side, a defect is formed in the advancing side of the weld, which is attributed to insufficient material flow. It is concluded that the contact surface of the laminate (Al or Cu) with the shoulder of the FSW tool influences the material flow and microstructure of welds.

Domestic demand-side management (DSM): Role of heat pumps and thermal energy storage (TES) systems

International Nuclear Information System (INIS)

Arteconi, A.; Hewitt, N.J.; Polonara, F.

2013-01-01

Heat pumps are seen as a promising technology for load management in the built environment, in combination with the smart grid concept. They can be coupled with thermal energy storage (TES) systems to shift electrical loads from high-peak to off-peak hours, thus serving as a powerful tool in demand-side management (DSM). This paper analyzes heat pumps with radiators or underfloor heating distribution systems coupled with TES with a view to showing how a heat pump system behaves and how it influences the building occupants' thermal comfort under a DSM strategy designed to flatten the shape of the electricity load curve by switching off the heat pump during peak hours (16:00–19:00). The reference scenario for the analysis was Northern Ireland (UK). The results showed that the heat pump is a good tool for the purposes of DSM, also thanks to the use of TES systems, in particular with heating distribution systems that have a low thermal inertia, e.g. radiators. It proved possible to achieve a good control of the indoor temperature, even if the heat pump was turned off for 3 h, and to reduce the electricity bill if a “time of use” tariff structure was adopted. -- Highlights: ► Heat pump heating systems with thermal energy storage are considered. ► System behavior is investigated during a DSM strategy for reducing peak energy demand. ► Heat pump heating systems demonstrate to be able to have an active role in DSM programs. ► A TES system must be coupled with the heat pump in presence of low thermal inertia heating distribution systems. ► Central role played by incentives schemes to promote this technology

Characterization of friction and wear behavior of friction modifiers used in wheel-rail contacts

NARCIS (Netherlands)

Oomen, M. A.; Bosman, R.; Lugt, P. M.

2017-01-01

Reliable traction between wheel and rail is an important issue in the railway industry. To reduce variations in the coefficient of friction, so-called “friction modifiers” (carrier with particles) are used. Twin-disk tests were done with three commercial friction modifiers, based on different

The future of the photovoltaic market (demand side/supply side)

International Nuclear Information System (INIS)

Zahedi, A.

1998-01-01

At present the main PV application market sectors are communications, leisure, boating, solar home systems, and water pumping. It is predicted that in the future, the largest photovoltaic market segments will be solar home photovoltaic systems, grid-connected small-scale photovoltaic systems, grid-connected medium-to-large scale photovoltaic systems, the communications sector and in the electrification of remote and isolated areas. The main factors favoring photovoltaic technology in remote and isolated areas result from: the high costs of conventional energy sources in remote locations; the loss of a scale-economy effect, which means specific costs of small photovoltaic systems are not much higher than those of larger photovoltaic systems; price of fuel, fuel transportation and spare part supplies. The major factors inhibiting the photovoltaic technology include high initial costs, lack of skilled man power, lack of good quality data and social acceptance. A roof top mounted photovoltaic system is one type of PV system which has attracted lots of interest among the people of north America and Europe. The generation of electricity by this system is attractive because: generation is on-site. This results in reduction of transmission costs and transmission losses; the cost of roofing tiles can be eliminated by using mounted PV systems instead; there is no need for additional land for power generation; visual impacts are limited. The objective of this paper is to review the development of the photovoltaic market in the recent 10 year period and discuss the future markets for this technology with respect to supply and demand

Price elasticity matrix of demand in power system considering demand response programs

Science.gov (United States)

Qu, Xinyao; Hui, Hongxun; Yang, Shengchun; Li, Yaping; Ding, Yi

2018-02-01

The increasing renewable energy power generations have brought more intermittency and volatility to the electric power system. Demand-side resources can improve the consumption of renewable energy by demand response (DR), which becomes one of the important means to improve the reliability of power system. In price-based DR, the sensitivity analysis of customer’s power demand to the changing electricity prices is pivotal for setting reasonable prices and forecasting loads of power system. This paper studies the price elasticity matrix of demand (PEMD). An improved PEMD model is proposed based on elasticity effect weight, which can unify the rigid loads and flexible loads. Moreover, the structure of PEMD, which is decided by price policies and load types, and the calculation method of PEMD are also proposed. Several cases are studied to prove the effectiveness of this method.

Why commercial customers are SIC of DSM [demand-side management] marketing

International Nuclear Information System (INIS)

Lewis, L.E.

1990-01-01

Studies have shown that the success of demand management programs, which have demonstrated economic benefits, depends on the level of customer participation. In order to have a better understanding of the decisionmaking process of commercial customers with respect to demand management programs, a study was undertaken to determine the preferences and the behavior of this class of clientele. This clientele, whose power consumption has been increasing at a faster rate than that of other sectors, represents a vast range of enterprises producing and supplying all kinds of products. Many of them operate from numerous geographic points on local, regional, national, and even world scales and are generally hierarchically organized. Because of these characteristics, their decisionmaking processes and their needs are equally complex, more so than in the residential sector. A multidimensional approach has been adopted to ensure that their needs are determined according to a quantitative and qualitative research method. The conclusions of the quantitative research have demonstrated that the frameworks representing different organizations respond differently to questions on their needs. It is also noted that certain commercial enterprises are of a cohesive nature (i.e. there is a consistency in understanding of corporate strategic and operational requirements at all hierarchical levels), while others are more diffuse. Those responsible for marketing demand management programs therefore must improve their understanding of the strategic and operational needs of their commercial customers in order to make their demand management programs productive in the view of the appropriate personnel at the hierarchical level applicable to the company concerned

Simulating residential demand response: Improving socio-technical assumptions in activity-based models of energy demand

OpenAIRE

McKenna, E.; Higginson, S.; Grunewald, P.; Darby, S. J.

2017-01-01

Demand response is receiving increasing interest as a new form of flexibility within low-carbon power systems. Energy models are an important tool to assess the potential capability of demand side contributions. This paper critically reviews the assumptions in current models and introduces a new conceptual framework to better facilitate such an assessment. We propose three dimensions along which change could occur, namely technology, activities and service expectations. Using this framework, ...

Tactile friction of topical formulations.

Science.gov (United States)

Skedung, L; Buraczewska-Norin, I; Dawood, N; Rutland, M W; Ringstad, L

2016-02-01

The tactile perception is essential for all types of topical formulations (cosmetic, pharmaceutical, medical device) and the possibility to predict the sensorial response by using instrumental methods instead of sensory testing would save time and cost at an early stage product development. Here, we report on an instrumental evaluation method using tactile friction measurements to estimate perceptual attributes of topical formulations. Friction was measured between an index finger and an artificial skin substrate after application of formulations using a force sensor. Both model formulations of liquid crystalline phase structures with significantly different tactile properties, as well as commercial pharmaceutical moisturizing creams being more tactile-similar, were investigated. Friction coefficients were calculated as the ratio of the friction force to the applied load. The structures of the model formulations and phase transitions as a result of water evaporation were identified using optical microscopy. The friction device could distinguish friction coefficients between the phase structures, as well as the commercial creams after spreading and absorption into the substrate. In addition, phase transitions resulting in alterations in the feel of the formulations could be detected. A correlation was established between skin hydration and friction coefficient, where hydrated skin gave rise to higher friction. Also a link between skin smoothening and finger friction was established for the commercial moisturizing creams, although further investigations are needed to analyse this and correlations with other sensorial attributes in more detail. The present investigation shows that tactile friction measurements have potential as an alternative or complement in the evaluation of perception of topical formulations. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Friction laws at the nanoscale.

Science.gov (United States)

Mo, Yifei; Turner, Kevin T; Szlufarska, Izabela

2009-02-26

Macroscopic laws of friction do not generally apply to nanoscale contacts. Although continuum mechanics models have been predicted to break down at the nanoscale, they continue to be applied for lack of a better theory. An understanding of how friction force depends on applied load and contact area at these scales is essential for the design of miniaturized devices with optimal mechanical performance. Here we use large-scale molecular dynamics simulations with realistic force fields to establish friction laws in dry nanoscale contacts. We show that friction force depends linearly on the number of atoms that chemically interact across the contact. By defining the contact area as being proportional to this number of interacting atoms, we show that the macroscopically observed linear relationship between friction force and contact area can be extended to the nanoscale. Our model predicts that as the adhesion between the contacting surfaces is reduced, a transition takes place from nonlinear to linear dependence of friction force on load. This transition is consistent with the results of several nanoscale friction experiments. We demonstrate that the breakdown of continuum mechanics can be understood as a result of the rough (multi-asperity) nature of the contact, and show that roughness theories of friction can be applied at the nanoscale.

Mechanical properties and microstructural evaluation of AA1100 to AZ31 dissimilar friction stir welds

Energy Technology Data Exchange (ETDEWEB)

Azizieh, M., E-mail: azizieh@gmail.com [Department of Materials Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz (Iran, Islamic Republic of); Sadeghi Alavijeh, A. [School of Mechatronic Systems Engineering, Simon Fraser University, 250-13450 102 Avenue, Surrey, BC V3T 0A3 (Canada); Abbasi, M. [High Temperature Energy Materials, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Balak, Z. [Department of Materials Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz (Iran, Islamic Republic of); Kim, H.S. [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of)

2016-02-15

In this paper, microstructure and mechanical properties of dissimilar friction stir welds of AA1100 and AZ31 were investigated to understand the effects of rotational and travel speed as well as pin position. The tensile results of welded samples revealed that the sound welds were formed when the stirring pin deviated from the centreline to the AZ31 side. The X-ray diffraction shows that Al{sub 3}Mg{sub 2} and Al{sub 12}Mg{sub 17} intermetallics formation occurs in the stir zone during the welding process. High hardness of these intermetallic phases increased the hardness of the stir zone to 110 Hv. The best tensile results were obtained in the sample processed in the range of 28–32 (rev/mm) rotational to travel speed ratio. - Highlights: • For Al to Mg friction stir welding, tool offset must be to Mg side. • There is an optimum rotational speed for obtain the highest strength. • Intermetallics form in any welding condition. • The volume fraction of intermetallic is directly related to FSW peak temperature.

Friction surfaced Stellite6 coatings

International Nuclear Information System (INIS)

Rao, K. Prasad; Damodaram, R.; Rafi, H. Khalid; Ram, G.D. Janaki; Reddy, G. Madhusudhan; Nagalakshmi, R.

2012-01-01

Solid state Stellite6 coatings were deposited on steel substrate by friction surfacing and compared with Stellite6 cast rod and coatings deposited by gas tungsten arc and plasma transferred arc welding processes. Friction surfaced coatings exhibited finer and uniformly distributed carbides and were characterized by the absence of solidification structure and compositional homogeneity compared to cast rod, gas tungsten arc and plasma transferred coatings. Friction surfaced coating showed relatively higher hardness. X-ray diffraction of samples showed only face centered cubic Co peaks while cold worked coating showed hexagonally close packed Co also. - Highlights: ► Stellite6 used as coating material for friction surfacing. ► Friction surfaced (FS) coatings compared with casting, GTA and PTA processes. ► Finer and uniformly distributed carbides in friction surfaced coatings. ► Absence of melting results compositional homogeneity in FS Stellite6 coatings.

Development of roller type side slip tester; Roller shiki side slip tester no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Nishiyama, S [Hiroshima City Industrial Technology Institute, Hiroshima (Japan); Harada, S; Harada, K

1997-10-01

This paper presents a new development of roller type side slip tester (RTSSI). The test equipment consists of four parts, which are developed in this research. These are a roller part, a control part, a remote control part and a CRT part. In this study, we especially investigated the mechanism and performance between tire and roller. We analyzed the amount of side slip with various toe angles. The developed tester is examined under the conditions that is considered in industrial applications. We investigated the influences of toe angle, size of tire, pressure of tire, coefficient of friction between tire and roller, pushing force of tire, revolution velocity of roller, axle load and so on. The validity of the developed RTSST is confirmed under these conditions. It was found that the RTSST can be used in practical use. Some measurement results are presented in the form of parametric plots. And we also compared measurements data between the RTSST and that of flat type using several automobiles. 4 refs., 8 figs., 4 tabs.

Simulation of Coulomb friction for a double wishbone front suspension; Simulation von Haft- und Gleitreibung am Beispiel einer Doppelquerlenker-Vorderradaufhaengung

Energy Technology Data Exchange (ETDEWEB)

Blanck, N.

1995-02-01

An exact method for the simulation of mechanical systems with one or more Coulomb friction elements is described. The Coulomb law is extended to two- and three-dimensional friction elements. The differential equations of the system without friction are generated with the finite element program NASTRAN. Subsequently, friction is included and the simulation is performed in a FORTRAN program. Friction between two degrees of freedom is simulated by equating their accelerations and adding the friction forces on the right-hand side of the equations. The method is demonstrated for the left front wheel double wishbone suspension of the Mercedes-Benz S-class. Friction in the lower and upper ball joint is modelled by two three-dimensional elements. Time and frequency domain results of four simulation examples with harmonic excitation force are shown in fig. 2, 3, 4 and 5. (orig.) [Deutsch] Es wird eine exakte Methode zur rechnerischen Simulation von mechanischen Systemen mit einem oder mehreren Coulombschen Reibelementen beschrieben, die ein-, zwei- oder dreiwertig (zum Beispiel Kugelgelenke) sein koennen. Die Differentialgleichungen des reibungsfreien Systems werden mit dem FE-Programm NASTRAN generiert. Die Simulation des durch Reibelemente ergaenzten Systems erfolgt in einem selbstentwickelten FORTRAN-Programm. Das Verfahren wird anhand einer harmonisch angeregten Doppelquerlenker-Vorderradaufhaengung von Mercedes-Benz mit zwei reibungsbehafteten Kugelgelenken demonstriert. (orig.)

Province gets serious about demand management

International Nuclear Information System (INIS)

Anon

2003-01-01

Directives from the Minister to the Ontario Energy Board to review options for demand-side management and demand reduction activities, and discussion papers describing the policy framework needed to implement demand management, are indications of renewed interest by the provincial government in demand-side management of Ontario's electric power supply. This renewed interest comes on the hills of a 5.5 per cent increase in electricity use, a 33 per cent increase in imports, and consumption records broken in 10 of the last 12 months. A 117-page study was released in April by Navigant Consulting, entitled 'Demand response blueprint for Ontario' which estimates that if the Ontario market had 250 MW of additional demand response, customers providing the demand response would have saved $20 million by reducing their demand when HOEP was greater than $120/MWh, while other customers would have saved $170 million due to lower HOEP, and would have enjoyed greater reliability as a result of the increase in reserve margins. Other than price signals to induce customers to save, the Navigant report suggest paying customers not to consume during peak periods. The report estimates that such a policy could generate a total demand response of 350 MW and a $235 million reduction in revenue to generators. The Navigan report also includes a large number of detailed analysis and recommendations. One among them is for the extensive use of interval meters for customers with loads over 200 kW. The report tends to be critical of the recent price freeze ordered by the Ontario government, claiming that the freeze could increase consumption, making prices more volatile and increasing the cost to the government even more. Successful demand response programs from California, New York and the New England states are cited as examples for Ontario to emulate

Argo packing friction research update

International Nuclear Information System (INIS)

VanTassell, D.M.

1994-01-01

This paper focuses on the issue of valve packing friction and its affect on the operability of motor- and air-operated valves (MOVs and AOVs). At this time, most nuclear power plants are required to perform postmaintenance testing following a packing adjustment or replacement. In many cases, the friction generated by the packing does not impact the operability window of a valve. However, to date there has not been a concerted effort to substantiate this claim. To quantify the effects of packing friction, it has become necessary to develop a formula to predict the friction effects accurately. This formula provides a much more accurate method of predicting packing friction than previously used factors based strictly on stem diameter. Over the past 5 years, Argo Packing Company has been developing and testing improved graphite packing systems at research facilities, such as AECL Chalk River and Wyle Laboratories. Much of this testing has centered around reducing and predicting friction that is related to packing. In addition, diagnostic testing for Generic Letter 89-10 MOVs and AOVs has created a significant data base. In July 1992 Argo asked several utilities to provide running load data that could be used to quantify packing friction repeatability and predictability. This technical paper provides the basis to predict packing friction, which will improve calculations for thrust requirements for Generic Leter 89-10 and future AOV programs. In addition, having an accurate packing friction formula will improve packing performance when low running loads are identified that would indicate insufficient sealing force

Emission impacts of demand-side programs: What have we achieved so far and how will recent policy decision change program choices?

International Nuclear Information System (INIS)

Tempchin, R.S.; Van den Berg, A.J.; Geba, V.B.; Felix, C.S.; Goldsmith, M.W.

1990-01-01

Congress and many state legislatures have been discussing the possibility of regulating carbon dioxide (CO 2 ), Sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), chlorofluorocarbons (CFC's) and other emissions. Key to these discussions is the recommendation that energy efficiency, and specifically electric utility demand-side management (DSM) programs, be used as an emission control option. Methods for incorporating the social or external costs of energy production into utility planning are being developed, and estimates of potential emission impacts attributed to DSM programs have been calculated. However, little research has calculated the actual emission impacts from existing DSM programs. The increasing need for electric energy services and fossil fuel generation create an apparent conflict with the risks and regulations associated with global climate change and clean air. Electric utility DSM programs can be used to resolve these conflicts by providing equal or better energy services and a net reduction in emissions. This paper summarizes three separate related research projects. The first study, Impacts of Electric Utility Demand-Side Management Programs on Power Plant Emissions, collects utility and state data on existing DSM programs to approximate the level of SO 2 , NO x , and CO 2 reductions on a regional and national basis. Phase 1 of this study is a completed survey of DSM savings by state. The second and third studies, Carbon Dioxide Reduction Through Electrification of the Industrial and Transportation Sectors, and Carbon Dioxide Reduction Through Electrification of the Residential and Commercial Sectors, compare selected high efficiency electric technologies with fossil-fueled alternatives to determine CO 2 emissions. Through these studies, the authors have begun to quantify the emissions impacts from utility DSM programs and efficient electric equipment

Demand side load management using a three step optimization methodology

NARCIS (Netherlands)

Bakker, Vincent; Bosman, M.G.C.; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria

2010-01-01

In order to keep a proper functional electricity grid and to prevent large investments in the current grid, the creation, transmission and consumption of electricity needs to be controlled and organized in a different way as done nowadays. Smart meters, distributed generation and -storage and demand

Effect of grafted oligopeptides on friction.

Science.gov (United States)

Iarikov, Dmitri D; Ducker, William A

2013-05-14

Frictional and normal forces in aqueous solution at 25 °C were measured between a glass particle and oligopeptide films grafted from a glass plate. Homopeptide molecules consisting of 11 monomers of either glutamine, leucine, glutamic acid, lysine, or phenylalanine and one heteropolymer were each "grafted from" an oxidized silicon wafer using microwave-assisted solid-phase peptide synthesis. The peptide films were characterized using X-ray photoelectron spectroscopy and secondary ion mass spectrometry. Frictional force measurements showed that the oligopeptides increased the magnitude of friction compared to that on a bare hydrophilic silicon wafer but that the friction was a strong function of the nature of the monomer unit. Overall we find that the friction is lower for more hydrophilic films. For example, the most hydrophobic monomer, leucine, exhibited the highest friction whereas the hydrophilic monomer, polyglutamic acid, exhibited the lowest friction at zero load. When the two surfaces had opposite charges, there was a strong attraction, adhesion, and high friction between the surfaces. Friction for all polymers was lower in phosphate-buffered saline than in pure water, which was attributed to lubrication via hydrated salt ions.

Frictional performance of ball screw

International Nuclear Information System (INIS)

Nakashima, Katuhiro; Takafuji, Kazuki

1985-01-01

As feed screws, ball screws have become to be adopted in place of trapezoidal threads. The structure of ball screws is complex, but those are the indispensable component of NC machine tools and machining centers, and are frequently used for industrial robots. As the problems in the operation of ball screws, there are damage, life and the performance related to friction. As to the damage and life, though there is the problem of the load distribution on balls, the results of the research on rolling bearings are applied. The friction of ball screws consists of the friction of balls and a spiral groove, the friction of a ball and a ball, the friction in a ball-circulating mechanism and the viscous friction of lubricating oil. It was decided to synthetically examine the frictional performance of ball screws, such as driving torque, the variation of driving torque, efficiency, the formation of oil film and so on, under the working condition of wide range, using the screws with different accuracy and the nuts of various circuit number. The experimental setup and the processing of the experimental data, the driving performance of ball screws and so on are reported. (Kako, I.)

Intelligent tires for identifying coefficient of friction of tire/road contact surfaces using three-axis accelerometer

International Nuclear Information System (INIS)

Matsuzaki, Ryosuke; Kamai, Kazuto; Seki, Ryosuke

2015-01-01

Intelligent tires equipped with sensors as well as the monitoring of the tire/road contact conditions are in demand for improving vehicle control and safety. With the aim of identifying the coefficient of friction of tire/road contact surfaces during driving, including during cornering, we develop an identification scheme for the coefficient of friction that involves estimation of the slip angle and applied force by using a single lightweight three-axis accelerometer attached on the inner surface of the tire. To validate the developed scheme, we conduct tire-rolling tests using an accelerometer-equipped tire with various slip angles on various types of road surfaces, including dry and wet surfaces. The results of these tests confirm that the estimated slip angle and applied force are reasonable. Furthermore, the identified coefficient of friction by the developed scheme agreed with that measured by standardized tests. (paper)

Effects of antimony trisulfide (Sb2S3) on sliding friction of automotive brake friction materials

Science.gov (United States)

Lee, Wan Kyu; Rhee, Tae Hee; Kim, Hyun Seong; Jang, Ho

2013-09-01

The effect of antimony trisulfide (Sb2S3) on the tribological properties of automotive brake friction materials was investigated using a Krauss type tribometer and a 1/5 scale dynamometer with a rigid caliper. Results showed that Sb2S3 improved fade resistance by developing transfer films on the disc surface at elevated temperatures. On the other hand, the rubbing surfaces of the friction material exhibited contact plateaus with a broader height distribution when it contained Sb2S3, indicating fewer contact junctions compared to the friction material with graphite. The friction material with Sb2S3 also exhibited a lower stick-slip propensity than the friction material with graphite. The improved fade resistance with Sb2S3 is attributed to its lubricating capability sustained at high temperatures, while the lower stick-slip propensity of the friction material with Sb2S3 is associated with the slight difference between its static and kinetic coefficients of friction and high normal stiffness.

Performance Assessment of Aggregation Control Services for Demand Response

DEFF Research Database (Denmark)

Bondy, Daniel Esteban Morales; Costanzo, Giuseppe Tommaso; Heussen, Kai

2014-01-01

Aggregation algorithms that provide services to the grid via demand side management are moving from research ideas to the market. With the diversity of the technology delivering such services, it becomes essential to establish transparent performance standards from a service delivery perspective...... of the quality of service provided by an aggregation control algorithm. By a detailed case study we present and an application of the index, comparing the performance of two different control architectures for demand side management delivering a distribution grid service....

Effect of friction time on the microstructure and mechanic properties of friction welded AISI 1040/Duplex stainless steel

Directory of Open Access Journals (Sweden)

İhsan Kırık

2000-06-01

Full Text Available In this study, the effect on the characteristic microstructure and mechanic properties of friction time on the couple steels AISI 1040/AISI 2205 stainless steel joining with friction welding method was experimentally investigated. Friction welding experiment were carried out in privately prepared PLC controlled continuous friction welding machine by us. Joints were carried out under 1700 rpm rotation speed, with 30MPa process friction pressure, 60MPa forging pressure, 4 second forging pressure and under 3, 5, 7, 9 and 11 second friction time, respectively. After friction welding, the bonding interface microstructures of the specimens were examined by SEM microscopy and EDS analysis. After weld microhardness and tensile strength of specimens were carried out. The result of applied tests and observations pointed out that the properties of microstructure were changed with friction time increased. The excellent tensile strength of joint observed on 1700 rpm rotation speed and 3 second friction time sample.

Development of a penetration friction apparatus (PFA) to measure the frictional performance of surgical suture.

Science.gov (United States)

Zhang, Gangqiang; Ren, Tianhui; Lette, Walter; Zeng, Xiangqiong; van der Heide, Emile

2017-10-01

Nowadays there is a wide variety of surgical sutures available in the market. Surgical sutures have different sizes, structures, materials and coatings, whereas they are being used for various surgeries. The frictional performances of surgical sutures have been found to play a vital role in their functionality. The high friction force of surgical sutures in the suturing process may cause inflammation and pain to the person, leading to a longer recovery time, and the second trauma of soft or fragile tissue. Thus, the investigation into the frictional performance of surgical suture is essential. Despite the unquestionable fact, little is actually known on the friction performances of surgical suture-tissue due to the lack of appropriate test equipment. This study presents a new penetration friction apparatus (PFA) that allowed for the evaluation of the friction performances of various surgical needles and sutures during the suturing process, under different contact conditions. It considered the deformation of tissue and can realize the puncture force measurements of surgical needles as well as the friction force of surgical sutures. The developed PFA could accurately evaluate and understand the frictional behaviour of surgical suture-tissue in the simulating clinical conditions. The forces measured by the PFA showed the same trend as that reported in literatures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Friction Stir Weld Restart+Reweld Repair Allowables

Science.gov (United States)

Clifton, Andrew

2008-01-01

A friction stir weld (FSW) repair method has been developed and successfully implemented on Al 2195 plate material for the Space Shuttle External Fuel Tank (ET). The method includes restarting the friction stir weld in the termination hole of the original weld followed by two reweld passes. Room temperature and cryogenic temperature mechanical properties exceeded minimum FSW design strength and compared well with the development data. Simulated service test results also compared closely to historical data for initial FSW, confirming no change to the critical flaw size or inspection requirements for the repaired weld. Testing of VPPA fusion/FSW intersection weld specimens exhibited acceptable strength and exceeded the minimum design value. Porosity, when present at the intersection was on the root side toe of the fusion weld, the "worst case" being 0.7 inch long. While such porosity may be removed by sanding, this "worst case" porosity condition was tested "as is" and demonstrated that porosity did not negatively affect the strength of the intersection weld. Large, 15-inch "wide panels" FSW repair welds were tested to demonstrate strength and evaluate residual stresses using photo stress analysis. All results exceeded design minimums, and photo stress analysis showed no significant stress gradients due to the presence of the restart and multi-pass FSW repair weld.

Microstructure and mechanical properties of hard zone in friction stir welded X80 pipeline steel relative to different heat input

Energy Technology Data Exchange (ETDEWEB)

Aydin, Hakan, E-mail: hakanay@uludag.edu.tr [Engineering and Architecture Faculty, Mechanical Engineering Department, Uludag University, 16059 Gorukle-Bursa (Turkey); Nelson, Tracy W. [Mechanical Engineering Department, Brigham Young University, 435 CTB, Provo, UT 84602 (United States)

2013-12-01

The study was conducted to investigate the microstructure and mechanical properties of the hard zone in friction stir welded X80 pipeline steel at different heat inputs. Microstructural analysis of the welds was carried out using optical microscopy, transmission electron microscopy, and microhardness. Heat input during friction stir welding process had a significant influence on the microstructure and mechanical properties in the hard zone along the advancing side of the weld nugget. Based on the results, the linear relationships between heat input and post-weld microstructures and mechanical properties in the hard zone of friction stir welded X80 steels were established. It can be concluded that with decrease in heat input the bainitic structure in the hard zone becomes finer and so hard zone strength increases.

Microstructure and mechanical properties of hard zone in friction stir welded X80 pipeline steel relative to different heat input

International Nuclear Information System (INIS)

Aydin, Hakan; Nelson, Tracy W.

2013-01-01

The study was conducted to investigate the microstructure and mechanical properties of the hard zone in friction stir welded X80 pipeline steel at different heat inputs. Microstructural analysis of the welds was carried out using optical microscopy, transmission electron microscopy, and microhardness. Heat input during friction stir welding process had a significant influence on the microstructure and mechanical properties in the hard zone along the advancing side of the weld nugget. Based on the results, the linear relationships between heat input and post-weld microstructures and mechanical properties in the hard zone of friction stir welded X80 steels were established. It can be concluded that with decrease in heat input the bainitic structure in the hard zone becomes finer and so hard zone strength increases

Friction in sheet metal forming

DEFF Research Database (Denmark)

Wiklund, D.; Liljebgren, M.; Berglund, J.

2010-01-01

and calls for functional tool surfaces that are durable in these severe tribological conditions. In this study the influence of tool surface topography on friction has been investigated. The frictional response was studied in a Bending Under Tension test. The results did show that a low frictional response...

Demand participation in the restructured Electric Reliability Council of Texas market

International Nuclear Information System (INIS)

Zarnikau, Jay W.

2010-01-01

Does an electricity market which has been restructured to foster competition provide greater opportunities for demand response than a traditional regulated utility industry? The experiences of the restructured Electric Reliability Council of Texas (ERCOT) market over the past eight years provide some hope that it is possible to design a competitive market which will properly value and accommodate demand response. While the overall level of demand response in ERCOT is below the levels enjoyed prior to restructuring, there have nonetheless been some promising advances, including the integration of demand-side resources into competitive markets for ancillary services. ERCOT's experiences demonstrate that the degree of demand participation in a restructured market is highly sensitive to the market design. But even in a market which has been deregulated to a large degree, regulatory intervention and special demand-side programs may be needed in order to bolster demand response. (author)

Demand-side bidding in Brazil; Leilao de eficiencia energetica no Brasil

Energy Technology Data Exchange (ETDEWEB)

Garcia, Agenor Gomes Pinto

2008-01-15

Since the New Electric Sector Model's conception an energy-efficiency auction, like the ones used to buy new energy, was considered. Recently, the subject has been frequently commented in studies and meetings. This thesis discuss the main issues about its implementation in Brazil and proposes a model for this. The first chapter shows the history and the Electric Sector actual frame, with emphasis in the energy planning, resumed after the 2001 electricity shortage, the structure created for the system expansion and analyses the results of the new energy's auctions until now. The second chapter studies how the energy-efficiency auction can affect agents and consumers and presents the auction theory, which is growing fast in recent years, and how it can be applied to the present case, showing the possible agents' behavior - ESCOs, larger consumers and appliance manufacturers, and its implication on the auction shape. The third chapter shows the past world experience in energy-efficiency selling - the USA DSB (demand-side bidding) and its actual results and an IEA (International Energy Agency) study about this market mechanism of energy-efficiency promotion. 'The DSB works but it's not simple' (Geller, 2006) sums up the main conclusion about DSB - it develops the M and V techniques and the ESCO industry, making energy-efficiency as good as new generation for system's growing. The fourth chapter presents a proposal for the energy-efficiency auction's implementation in Brazil - its opportunity, resources source, regional aspects and the steps to get there. The fifth chapter analyses the M and V 's techniques and shows examples of the four options for projects - the M and V is essential for the auction success and its development, on the other hand, can leverage the energy-efficiency market in Brazil. Finally, the last chapter concludes that the energy-efficiency auction can make a great contribution for energy efficiency and energy planning, but it can't be the only

Demand Side Management in Nearly Zero Energy Buildings Using Heuristic Optimizations

Directory of Open Access Journals (Sweden)

Nadeem Javaid

2017-08-01

Full Text Available Today’s buildings are responsible for about 40% of total energy consumption and 30–40% of carbon emissions, which are key concerns for the sustainable development of any society. The excessive usage of grid energy raises sustainability issues in the face of global changes, such as climate change, population, economic growths, etc. Traditionally, the power systems that deliver this commodity are fuel operated and lead towards high carbon emissions and global warming. To overcome these issues, the recent concept of the nearly zero energy building (nZEB has attracted numerous researchers and industry for the construction and management of the new generation buildings. In this regard, this paper proposes various demand side management (DSM programs using the genetic algorithm (GA, teaching learning-based optimization (TLBO, the enhanced differential evolution (EDE algorithm and the proposed enhanced differential teaching learning algorithm (EDTLA to manage energy and comfort, while taking the human preferences into consideration. Power consumption patterns of shiftable home appliances are modified in response to the real-time price signal in order to get monetary benefits. To further improve the cost and user discomfort objectives along with reduced carbon emission, renewable energy sources (RESs are also integrated into the microgrid (MG. The proposed model is implemented in a smart residential complex of multiple homes under a real-time pricing environment. We figure out two feasible regions: one for electricity cost and the other for user discomfort. The proposed model aims to deal with the stochastic nature of RESs while introducing the battery storage system (BSS. The main objectives of this paper include: (1 integration of RESs; (2 minimization of the electricity bill (cost and discomfort; and (3 minimizing the peak to average ratio (PAR and carbon emission. Additionally, we also analyze the tradeoff between two conflicting objectives

Research in the Netherlands on system integration. Analysis of supply and demand

International Nuclear Information System (INIS)

Van Werhoven, M.; Bruel, R.

2000-07-01

Results of studies on integrated systems can contribute to the realization of sustainability targets of the Dutch government. In this report an overview is given of the supply-side and the demand-side of energy-related research on system integration. Also, recommendations to improve the coordination between supply and demand are given. 14 refs

High-velocity frictional properties of gabbro

Science.gov (United States)

Tsutsumi, Akito; Shimamoto, Toshihiko

High-velocity friction experiments have been performed on a pair of hollow-cylindrical specimens of gabbro initially at room temperature, at slip rates from 7.5 mm/s to 1.8 m/s, with total circumferential displacements of 125 to 174 m, and at normal stresses to 5 MPa, using a rotary-shear high-speed friction testing machine. Steady-state friction increases slightly with increasing slip rate at slip rates to about 100 mm/s (velocity strengthening) and it decreases markedly with increasing slip rate at higher velocities (velocity weakening). Steady-state friction in the velocity weakening regime is lower for the non-melting case than the frictional melting case, due perhaps to severe thermal fracturing. A very large peak friction is always recognized upon the initiation of visible frictional melting, presumably owing to the welding of fault surfaces upon the solidification of melt patches. Frictional properties thus change dramatically with increasing displacement at high velocities, and such a non-linear effect must be incorporated into the analysis of earthquake initiation processes.

JOINING DISSIMILAR MATERIALS USING FRICTION STIR SCRIBE TECHNIQUE

Energy Technology Data Exchange (ETDEWEB)

Upadhyay, Piyush; Hovanski, Yuri; Jana, Saumyadeep; Fifield, Leonard S.

2016-09-01

Development of robust and cost effective method of joining dissimilar materials can provide a critical pathway to enable widespread use of multi-material design and components in mainstream industrial applications. The use of multi-material components such as Steel-Aluminum, Aluminum-Polymer allows design engineers to optimize material utilization based on service requirements and often lead weight and cost reductions. However producing an effective joint between materials with vastly different thermal, microstructural and deformation response is highly problematic using conventional joining and /or fastening methods. This is especially challenging in cost sensitive high volume markets that largely rely on low–cost joining solutions. Friction Stir Scribe technology was developed to meet the demands of joining materials with drastically different properties and melting regimes. The process enables joining of light metals like Magnesium and Aluminum to high temperature materials like Steels and Titanium. Additionally viable joints between polymer composites and metal can also be made using this method. This paper will present state of the art, progress made and challenges associated with this innovative derivative of Friction Stir welding in reference to joining dissimilar metals and polymer/metal combinations.

Joining Dissimilar Materials Using Friction Stir Scribe Technique

Energy Technology Data Exchange (ETDEWEB)

Upadhyay, Piyush [Pacific Northwest National Laboratory, Richland 99352, WA e-mail: piyush.upadhyay@pnnl.gov; Hovanski, Yuri [Pacific Northwest National Laboratory, Richland 99352, WA; Jana, Saumyadeep [Pacific Northwest National Laboratory, Richland 99352, WA; Fifield, Leonard S. [Pacific Northwest National Laboratory, Richland 99352, WA

2016-10-03

Development of a robust and cost-effective method of joining dissimilar materials could provide a critical pathway to enable widespread use of multi-material designs and components in mainstream industrial applications. The use of multi-material components such as steel-aluminum and aluminum-polymer would allow design engineers to optimize material utilization based on service requirements and could often lead to weight and cost reductions. However, producing an effective joint between materials with vastly different thermal, microstructural, and deformation responses is highly problematic using conventional joining and/or fastening methods. This is especially challenging in cost sensitive, high volume markets that largely rely on low cost joining solutions. Friction stir scribe technology was developed to meet the demands of joining materials with drastically different properties and melting regimes. The process enables joining of light metals like magnesium and aluminum to high temperature materials like steel and titanium. Viable joints between polymer composites and metal can also be made using this method. This paper will present the state of the art, progress made, and challenges associated with this innovative derivative of friction stir welding in reference to joining dissimilar metals and polymer/metal combinations.

Friction stir welding (FSW of aluminium foam sandwich panels

Directory of Open Access Journals (Sweden)

M. Bušić

2016-07-01

Full Text Available The article focuses on the influence of welding speed and tool tilt angle upon the mechanical properties at the friction stir welding of aluminium foam sandwich panels. Double side welding was used for producing butt welds of aluminium sandwich panels applying insertion of extruded aluminium profile. Such insertion provided lower pressure of the tool upon the aluminium panels, providing also sufficient volume of the material required for the weldment formation. Ultimate tensile strength and flexural strength for three-point bending test have been determined for samples taken from the welded joints. Results have confirmed anticipated effects of independent variables.

Improved side information generation for distributed video coding

DEFF Research Database (Denmark)

Huang, Xin; Forchhammer, Søren

2008-01-01

As a new coding paradigm, distributed video coding (DVC) deals with lossy source coding using side information to exploit the statistics at the decoder to reduce computational demands at the encoder. The performance of DVC highly depends on the quality of side information. With a better side...... information generation method, fewer bits will be requested from the encoder and more reliable decoded frames will be obtained. In this paper, a side information generation method is introduced to further improve the rate-distortion (RD) performance of transform domain distributed video coding. This algorithm...

Friction and wear calculation methods

CERN Document Server

Kragelsky, I V; Kombalov, V S

1981-01-01

Friction and Wear: Calculation Methods provides an introduction to the main theories of a new branch of mechanics known as """"contact interaction of solids in relative motion."""" This branch is closely bound up with other sciences, especially physics and chemistry. The book analyzes the nature of friction and wear, and some theoretical relationships that link the characteristics of the processes and the properties of the contacting bodies essential for practical application of the theories in calculating friction forces and wear values. The effect of the environment on friction and wear is a

Friction and anchorage loading revisited.

Science.gov (United States)

Dholakia, Kartik D

2012-01-01

Contemporary concepts of sliding mechanics explain that friction is inevitable. To overcome this frictional resistance, excess force is required to retract the tooth along the archwire (ie, individual retraction of canines, en masse retraction of anterior teeth), in addition to the amount of force required for tooth movement. The anterior tooth retraction force, in addition to excess force (to overcome friction), produces reciprocal protraction force on molars, thereby leading to increased anchorage loading. However, this traditional concept was challenged in recent literature, which was based on the finite element model, but did not bear correlation to the clinical scenario. This article will reinforce the fact that clinically, friction increases anchorage loading in all three planes of space, considering the fact that tooth movement is a quasistatic process rather than a purely continuous or static one, and that conventional ways of determining the effects of static or dynamic friction on anchorage load cannot be applied to clinical situations (which consist of anatomical resistance units and a complex muscular force system). The article does not aim to quantify friction and its effect on the amount of anchorage load. Rather, a new perspective regarding the role of various additional factors (which is not explained by contemporary concept) that may influence friction and anchorage loading is provided..

The influence of zigzag-curve defect on the fatigue properties of friction stir welds in 7075-T6 Al alloy

International Nuclear Information System (INIS)

Di Shusheng; Yang Xinqi; Fang Dapeng; Luan Guohong

2007-01-01

The microstructure and fatigue properties of friction stir welded joints of 7075-T6 Al alloy were discussed. It was shown that the zigzag-curve defect at the root of welds is Key factor to reduce the fatigue performance of single-sided friction stir welded joints of 7075-T6 high strength aluminum alloy. On the other hand, the FSW joints of 7075-T6 Al alloy achieved higher fatigue strength compared to the traditional fusion design curves IIW FAT40 and Draft Eurocode 9 design category 55-6 for structural aluminum alloy components

The effect of friction in coulombian damper

Science.gov (United States)

Wahad, H. S.; Tudor, A.; Vlase, M.; Cerbu, N.; Subhi, K. A.

2017-02-01

The study aimed to analyze the damping phenomenon in a system with variable friction, Stribeck type. Shock absorbers with limit and dry friction, is called coulombian shock-absorbers. The physical damping vibration phenomenon, in equipment, is based on friction between the cushioning gasket and the output regulator of the shock-absorber. Friction between them can be dry, limit, mixture or fluid. The friction is depending on the contact pressure and lubricant presence. It is defined dimensionless form for the Striebeck curve (µ friction coefficient - sliding speed v). The friction may damp a vibratory movement or can maintain it (self-vibration), depending on the µ with v (it can increase / decrease or it can be relative constant). The solutions of differential equation of movement are obtained for some work condition of one damper for automatic washing machine. The friction force can transfer partial or total energy or generates excitation energy in damper. The damping efficiency is defined and is determined analytical for the constant friction coefficient and for the parabolic friction coefficient.

Two-Dimensional Computational Flow Analysis and Frictional Characteristics Model for Red Blood Cell under Inclined Centrifuge Microscopy

Science.gov (United States)

Funamoto, Kenichi; Hayase, Toshiyuki; Shirai, Atsushi

Simplified two-dimensional flow analysis is performed in order to simulate frictional characteristics measurement of red blood cells moving on a glass plate in a medium with an inclined centrifuge microscope. Computation under various conditions reveals the influences of parameters on lift, drag, and moment acting on a red blood cell. Among these forces, lift appears only when the cell is longitudinally asymmetric. By considering the balance of forces, the frictional characteristics of the red blood cell are modeled as the sum of Coulomb friction and viscous drag. The model describes the possibility that the red blood cell deforms to expand in the front side in response to the inclined centrifugal force. When velocity exceeds some critical value, the lift overcomes the normal centrifugal force component, and the thickness of the plasma layer between the cell and the glass plate increases from the initial value of the plasma protein thickness.

Effect of hexagonal boron nitride and calcined petroleum coke on friction and wear behavior of phenolic resin-based friction composites

International Nuclear Information System (INIS)

Yi Gewen; Yan Fengyuan

2006-01-01

Calcined petroleum coke (CPC) and hexagonal boron nitride (h-BN) were used as the friction modifiers to improve the friction and wear properties of phenolic resin-based friction composites. Thus, the composites with different relative amounts of CPC and h-BN as the friction modifiers were prepared by compression molding. The hardness and bending strength of the friction composites were measured. The friction and wear behaviors of the composites sliding against cast iron at various temperatures were evaluated using a pin-on-disc test rig. The worn surfaces and wear debris of the friction composites were analyzed by means of scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. It was found that the hybrid of the two friction modifiers was effective to significantly decrease the wear rate and stabilize the friction coefficient of the friction composites at various temperatures by forming a uniform lubricating and/or transferred film on the rubbing surfaces. The uniform and durable transfer films were also able to effectively diminish the direct contact between the friction composite and the cast iron counterpart and hence prevent severe wear of the latter as well. The effectiveness of the hybrid of CPC and h-BN in improving the friction and wear behavior of the phenolic resin-based friction modifiers could be attributed to the complementary action of the 'low temperature' lubricity of CPC and the 'high temperature' lubricity of h-BN. The optimum ratio of the two friction modifiers CPC and h-BN in the friction composites was suggested to be 1:1, and the corresponding friction composite showed the best friction-reducing and antiwear abilities

Internal friction, microstructure, and radiation effects

International Nuclear Information System (INIS)

Wechsler, M.S.; Sommer, W.F.; Davidson, D.R.

1984-01-01

A brief review is given of internal friction relaxation peaks and background internal friction. The microstructural origin of the internal friction is discussed. Particular emphasis is placed on radiation effects

Advances on LuGre friction model

OpenAIRE

Fuad, Mohammad; Ikhouane, Fayçal

2013-01-01

LuGre friction model is an ordinary differential equation that is widely used in describing the friction phenomenon for mechanical systems. The importance of this model comes from the fact that it captures most of the friction behavior that has been observed including hysteresis. In this paper, we study some aspects related to the hysteresis behavior induced by the LuGre friction model.

A Pedagogical Model of Static Friction

OpenAIRE

Pickett, Galen T.

2015-01-01

While dry Coulombic friction is an elementary topic in any standard introductory course in mechanics, the critical distinction between the kinetic and static friction forces is something that is both hard to teach and to learn. In this paper, I describe a geometric model of static friction that may help introductory students to both understand and apply the Coulomb static friction approximation.

Friction in volcanic environments

Science.gov (United States)

Kendrick, Jackie E.; Lavallée, Yan

2016-04-01

Volcanic landscapes are amongst the most dynamic on Earth and, as such, are particularly susceptible to failure and frictional processes. In rocks, damage accumulation is frequently accompanied by the release of seismic energy, which has been shown to accelerate in the approach to failure on both a field and laboratory scale. The point at which failure occurs is highly dependent upon strain-rate, which also dictates the slip-zone properties that pertain beyond failure, in scenarios such as sector collapse and pyroclastic flows as well as the ascent of viscous magma. High-velocity rotary shear (HVR) experiments have provided new opportunities to overcome the grand challenge of understanding faulting processes during volcanic phenomena. Work on granular ash material demonstrates that at ambient temperatures, ash gouge behaves according to Byerlee's rule at low slip velocities, but is slip-weakening, becoming increasingly lubricating as slip ensues. In absence of ash along a slip plane, rock-rock friction induces cataclasis and heating which, if sufficient, may induce melting (producing pseudotachylyte) and importantly, vesiculation. The viscosity of the melt, so generated, controls the subsequent lubrication or resistance to slip along the fault plane thanks to non-Newtonian suspension rheology. The shear-thinning behaviour and viscoelasticity of frictional melts yield a tendency for extremely unstable slip, and occurrence of frictional melt fragmentation. This velocity-dependence acts as an important feedback mechanism on the slip plane, in addition to the bulk composition, mineralogy and glass content of the magma, that all influence frictional behaviour. During sector collapse events and in pyroclastic density currents it is the frictional properties of the rocks and ash that, in-part, control the run-out distance and associated risk. In addition, friction plays an important role in the eruption of viscous magmas: In the conduit, the rheology of magma is integral

Friction coefficient dependence on electrostatic tribocharging.

Science.gov (United States)

Burgo, Thiago A L; Silva, Cristiane A; Balestrin, Lia B S; Galembeck, Fernando

2013-01-01

Friction between dielectric surfaces produces patterns of fixed, stable electric charges that in turn contribute electrostatic components to surface interactions between the contacting solids. The literature presents a wealth of information on the electronic contributions to friction in metals and semiconductors but the effect of triboelectricity on friction coefficients of dielectrics is as yet poorly defined and understood. In this work, friction coefficients were measured on tribocharged polytetrafluoroethylene (PTFE), using three different techniques. As a result, friction coefficients at the macro- and nanoscales increase many-fold when PTFE surfaces are tribocharged, but this effect is eliminated by silanization of glass spheres rolling on PTFE. In conclusion, tribocharging may supersede all other contributions to macro- and nanoscale friction coefficients in PTFE and probably in other insulating polymers.

Metal Flow in Friction Stir Welding

Science.gov (United States)

Nunes, Arthur C., Jr.

2006-01-01

The plastic deformation field in Friction Stir Welding (FSW) is compared to that in metal cutting. A shear surface around the FSW tool analogous to the metal cutting shear plane is identified and comprises the basis of the "rotating plug" flow field model and the "wiping" model of tool interaction with weld metal. Within the context of these models: The FSW shear rate is estimated to be comparable to metal cutting shear rates. The effect of tool geometry on the FSW shear surface is discussed and related to published torque measurements. Various FS W structural features are explained, including a difference in structure of bimetallic welds when alloys on the advancing and retreating sides of the weld seam are exchanged. The joining mechanism and critical parameters of the FSW process are made clear.

On the Mobile Communication Requirements for the Demand-Side Management of Electric Vehicles

Directory of Open Access Journals (Sweden)

Stefano Rinaldi

2018-05-01

Full Text Available The rising concerns about global warming and environmental pollution are increasingly pushing towards the replacement of road vehicles powered by Internal Combustion Engines (ICEs. Electric Vehicles (EVs are generally considered the best candidates for this transition, however, existing power grids and EV management systems are not yet ready for a large penetration of EVs, and the current opinion of the scientific community is that further research must be done in this field. The so-called Vehicle-to-Grid (V2G concept plays a relevant role in this scenario by providing the communication capabilities required by advanced control and Demand-Side Management (DSM strategies. Following this research trend, in this paper the communication requirements for the DSM of EVs in urban environments are discussed, by focusing on the mobile communication among EVs and smart grids. A specific system architecture for the DSM of EVs moving inside urban areas is proposed and discussed in terms of the required data throughput. In addition, the use of a Low-Power Wide-Area Network (LPWAN solution—the Long-Range Wide Area Network (LoRaWAN technology—is proposed as a possible alternative to cellular-like solutions, by testing an experimental communication infrastructure in a real environment. The results show that the proposed LPWAN technology is capable to handle an adequate amount of information for the considered application, and that one LoRa base station is able to serve up to 438 EVs per cell, and 1408 EV charging points.

Chirality-dependent friction of bulk molecular solids.

Science.gov (United States)

Yang, Dian; Cohen, Adam E

2014-08-26

We show that the solid-solid friction between bulk chiral molecular solids can depend on the relative chirality of the two materials. In menthol and 1-phenyl-1-butanol, heterochiral friction is smaller than homochiral friction, while in ibuprofen, heterochiral friction is larger. Chiral asymmetries in the coefficient of sliding friction vary with temperature and can be as large as 30%. In the three compounds tested, the sign of the difference between heterochiral and homochiral friction correlated with the sign of the difference in melting point between racemate (compound or conglomerate) and pure enantiomer. Menthol and ibuprofen each form a stable racemic compound, while 1-phenyl-1-butanol forms a racemic conglomerate. Thus, a difference between heterochiral and homochiral friction does not require the formation of a stable interfacial racemic compound. Measurements of chirality-dependent friction provide a unique means to distinguish the role of short-range intermolecular forces from all other sources of dissipation in the friction of bulk molecular solids.

A Simple Device For Measuring Skin Friction

Directory of Open Access Journals (Sweden)

Gupta A.B

1995-01-01

Full Text Available A simple device for measuring skin friction in vivo is described. The frictional coefficient of normal Indian skin and the effect of hydration and application of talc and glycerol on the frictional coefficient and also the friction of ichthyotic skin have been determined with its help. The average value of friction of friction of normal India skin at forearm is found to be 0.41 +- 0.08, the hydration raises the value to 0.71 +- 0.11 and the effect of glycerol is also to school it up to 0.70+- 0.05, almost equal to that of water. The effect of talc however is opposite and its application lowers the friction to 0.21+-0.07. The mean coeff of friction for ichthyotic skin is found to be 0.21+- 0.0.5, which closely agrees with talc-treated normal skin. A good positive correlation (p<0.01 between friction and sebum level at skin site, with r = 0.64, has been observed.

Internal friction and absence of dilatancy of packings of frictionless polygons.

Science.gov (United States)

Azéma, Émilien; Radjaï, Farhang; Roux, Jean-Noël

2015-01-01

By means of numerical simulations, we show that assemblies of frictionless rigid pentagons in slow shear flow possess an internal friction coefficient (equal to 0.183±0.008 with our choice of moderately polydisperse grains) but no macroscopic dilatancy. In other words, despite side-side contacts tending to hinder relative particle rotations, the solid fraction under quasistatic shear coincides with that of isotropic random close packings of pentagonal particles. Properties of polygonal grains are thus similar to those of disks in that respect. We argue that continuous reshuffling of the force-bearing network leads to frequent collapsing events at the microscale, thereby causing the macroscopic dilatancy to vanish. Despite such rearrangements, the shear flow favors an anisotropic structure that is at the origin of the ability of the system to sustain shear stress.

A semi-distributed electric demand-side management system with PV generation for self-consumption enhancement

International Nuclear Information System (INIS)

Castillo-Cagigal, M.; Gutierrez, A.; Monasterio-Huelin, F.; Caamano-Martin, E.; Masa, D.; Jimenez-Leube, J.

2011-01-01

Highlights: → We have developed a DSM system with PV electricity and battery storage. → To implement the DSM system, we have developed a modular architecture. → Simulations and real experiments have been executed for different weather conditions. → The use of theses technologies increase the self-consumed energy. -- Abstract: This paper presents the operation of an Electrical Demand-Side Management (EDSM) system in a real solar house. The use of EDSM is one of the most important action lines to improve the grid electrical efficiency. The combination between the EDSM and the PV generation performs a new control level in the local electric behavior and allows new energy possibilities. The solar house used as test-bed for the EDSM system owns a PV generator, a lead-acid battery storage system and a grid connection. The electrical appliances are controllable from an embedded computer. The EDSM is implemented by a control system which schedules the tasks commanded by the user. By using the control system, we define the house energy policy and improve the energy behavior with regard to a selected energy criterion, self-consumption. The EDSM system favors self-consumption with regard to a standard user behavior and reduces the energy load from the grid.

Non-uniform Pressure Distribution in Draw-Bend Friction Test and its Influence on Friction Measurement

International Nuclear Information System (INIS)

Kim, Young Suk; Jain, Mukesh K.; Metzger, Don R.

2005-01-01

From various draw-bend friction tests with sheet metals at lubricated conditions, it has been unanimously reported that the friction coefficient increases as the pin diameter decreases. However, a proper explanation for this phenomenon has not been given yet. In those experiments, tests were performed for different pin diameters while keeping the same average contact pressure by adjusting applied tension forces. In this paper, pressure profiles at pin/strip contacts and the changes in the pressure profiles depending on pin diameters are investigated using finite element simulations. To study the effect of the pressure profile changes on friction measurements, a non-constant friction model (Stribeck friction model), which is more realistic for the lubricated sheet metal contacts, is implemented into the finite element code and applied to the simulations. The study shows that the non-uniformity of the pressure profile increases and the pin/strip contact angle decreases as the pin diameter decreases, and these phenomena increase the friction coefficient, which is calculated from the strip tension forces using a conventional rope-pulley equation

Criteria for demand response systems

NARCIS (Netherlands)

Lampropoulos, I.; Kling, W.L.; Bosch, van den P.P.J.; Ribeiro, P.F.; Berg, van den J.

2013-01-01

The topic of demand side management is currently becoming more important than ever, in parallel with the further deregulation of the electricity sector, and the increasing integration of renewable energy sources. A historical review of automation integration in power system control assists in

A Multi-Objective Demand Side Management Considering ENS Cost in Smart Grids

DEFF Research Database (Denmark)

Yousefi Khanghah, Babak; Ghassemzadeh, Saeid; Hosseini, Seyed Hossein

2017-01-01

In this paper a new method is presented to achieve economic exploitation and proper usage of network capacity by exerting controlling actions over flexible loads and energy storage (ES) equipment. Multi-objective planning for demand response programs (DRP) and battery management policies is carried...... out by considering energy not supplied (ENS). In order to achieve an optimal scheduling, charge/discharge control for batteries, demand response programs and dispatch of controllable distributed generations (DGs) are also considered. Then, the balanced cost and benefits of participants are evaluated...

Modeling and data analysis of the NASA-WSTF frictional heating apparatus - Effects of test parameters on friction coefficient

Science.gov (United States)

Zhu, Sheng-Hu; Stoltzfus, Joel M.; Benz, Frank J.; Yuen, Walter W.

1988-01-01

A theoretical model is being developed jointly by the NASA White Sands Test Facility (WSTF) and the University of California at Santa Barbara (UCSB) to analyze data generated from the WSTF frictional heating test facility. Analyses of the data generated in the first seconds of the frictional heating test are shown to be effective in determining the friction coefficient between the rubbing interfaces. Different friction coefficients for carobn steel and Monel K-500 are observed. The initial condition of the surface is shown to affect only the initial value of the friction coefficient but to have no significant influence on the average steady-state friction coefficient. Rotational speed and the formation of oxide film on the rotating surfaces are shown to have a significant effect on the friction coefficient.

Kinetic Friction of Sport Fabrics on Snow

Directory of Open Access Journals (Sweden)

Werner Nachbauer

2016-03-01

Full Text Available After falls, skiers or snowboarders often slide on the slope and may collide with obstacles. Thus, the skier’s friction on snow is an important factor to reduce incidence and severity of impact injuries. The purpose of this study was to measure snow friction of different fabrics of ski garments with respect to roughness, speed, and contact pressure. Three types of fabrics were investigated: a commercially available ski overall, a smooth downhill racing suit, and a dimpled downhill racing suit. Friction was measured for fabrics taped on a short ski using a linear tribometer. The fabrics’ roughness was determined by focus variation microscopy. Friction coefficients were between 0.19 and 0.48. Roughness, friction coefficient, and friction force were highest for the dimpled race suit. The friction force of the fabrics was higher for the higher contact pressure than for the lower one at all speeds. It was concluded that the main friction mechanism for the fabrics was dry friction. Only the fabric with the roughest surface showed friction coefficients, which were high enough to sufficiently decelerate a sliding skier on beginner and intermediate slopes.

Friction coefficient dependence on electrostatic tribocharging

Science.gov (United States)

Burgo, Thiago A. L.; Silva, Cristiane A.; Balestrin, Lia B. S.; Galembeck, Fernando

2013-01-01

Friction between dielectric surfaces produces patterns of fixed, stable electric charges that in turn contribute electrostatic components to surface interactions between the contacting solids. The literature presents a wealth of information on the electronic contributions to friction in metals and semiconductors but the effect of triboelectricity on friction coefficients of dielectrics is as yet poorly defined and understood. In this work, friction coefficients were measured on tribocharged polytetrafluoroethylene (PTFE), using three different techniques. As a result, friction coefficients at the macro- and nanoscales increase many-fold when PTFE surfaces are tribocharged, but this effect is eliminated by silanization of glass spheres rolling on PTFE. In conclusion, tribocharging may supersede all other contributions to macro- and nanoscale friction coefficients in PTFE and probably in other insulating polymers. PMID:23934227

Wear calculation possibility of slide-friction pair "shaft-plain bearing" for four-stroke engines

Science.gov (United States)

Springis, Guntis; Rudzitis, Janis; Avisane, Anita; Kumermanis, Maris

2013-12-01

The issues of the service life and its prediction for main four stroke engine parts such as shaft-plain bearing have always been of particular importance. The article determines the most suitable mathematical calculation model allowing considering the set of parameters needed for the slide-friction pair's calculation, thus achieving a result as precise as possible. Since the wear process is variable and many-sided it is influenced by very many different parameters, for example, the surface geometry (roughness, waviness, form deviation, etc.), the physical and mechanical conditions of the upper layer, component material, wear regime, wear temperature, etc. The offered wear calculation model taking into consideration as much as possible wear affecting parameters is based on the fatigue theory regularities of the friction surface's destroying, using the approach of probability theory.

Heat transfer and friction characteristics in steam cooled rectangular channels with rib turbulators

Energy Technology Data Exchange (ETDEWEB)

Gong, Jianying; Gao, Tieyu; Li, Guojun [Xi' an Jiaotong University, Xi' an (China)

2014-01-15

We studied the heat transfer and friction characteristics in steam-cooled rectangular channels with rib turbulators on W side or H side walls in the Reynolds number (Re) range of 10000-80000. Each of the test channels was welded by four stainless steel plates to simulate the actual geometry and heat transfer structure of blade/vane internal cooling passage. The length of the channel L was 1000 mm, the cross section of the channel was 40 mm X 80 mm, and the pitch-to-rib height ratio p/e was kept at 10. The channel blockage ratio (W/H) was 0.047. Results showed that the Nusselt number (Nu) distributions displayed different trends at the entrance region with the increase of Re for the rib turbulators on the W side walls. The heat transfer performance of the rib turbulators on the H side walls was about 24- 27% higher than that on the W side walls at the same pumping power. In addition, semi-empirical correlations for the two cases, rib turbulators on W side walls and rib turbulators on H side walls, were developed based on the heat transfer results, which could be used in the design of the internal cooling passage of new generation steam-cooled gas turbine blade/vane.

Increased competition on the supply side of the Western European natural gas market

International Nuclear Information System (INIS)

Golombek, R.; Gjelsvik, E.; Rosendahl, K.E.

1998-01-01

This paper analyzes how the supply side of the Western European natural gas market may react if the demand side becomes competitive. The authors show--using a numerical model of the Western European natural gas market--that once the demand side of the market is liberalized, each gas-producing country has an incentive to break up its gas sellers. The model therefore suggests that there may be numerous producers in a liberalized natural gas market. Hence, in a liberalized market consumers will not be exploited by suppliers

Polymer friction Molecular Dynamics

DEFF Research Database (Denmark)

Sivebæk, Ion Marius; Samoilov, Vladimir N.; Persson, Bo N. J.

We present molecular dynamics friction calculations for confined hydrocarbon solids with molecular lengths from 20 to 1400 carbon atoms. Two cases are considered: a) polymer sliding against a hard substrate, and b) polymer sliding on polymer. In the first setup the shear stresses are relatively...... independent of molecular length. For polymer sliding on polymer the friction is significantly larger, and dependent on the molecular chain length. In both cases, the shear stresses are proportional to the squeezing pressure and finite at zero load, indicating an adhesional contribution to the friction force....

Australia's long-term electricity demand forecasting using deep neural networks

OpenAIRE

Hamedmoghadam, Homayoun; Joorabloo, Nima; Jalili, Mahdi

2018-01-01

Accurate prediction of long-term electricity demand has a significant role in demand side management and electricity network planning and operation. Demand over-estimation results in over-investment in network assets, driving up the electricity prices, while demand under-estimation may lead to under-investment resulting in unreliable and insecure electricity. In this manuscript, we apply deep neural networks to predict Australia's long-term electricity demand. A stacked autoencoder is used in...

Comparison of the marketing of demand response capacity and of power plant capacity in the minutes reserve market; Vergleich der Vermarktung von Demand-Response- und Kraftwerksleistung auf dem Minutenreservemarkt

Energy Technology Data Exchange (ETDEWEB)

Marz, Waldemar; Tzscheutschler, Peter [Technische Univ. Muenchen (Germany). Lehrstuhl fuer Energiewirtschaft und Anwendungstechnik; Henle, Markus [Stadtwerke Muenchen (Germany). Energiewirtschaft

2013-03-15

The greatest challenge in integrating renewable energies into the German and European power supply system lies in levelling out the imbalances between the fluctuating supply of energy from the wind and sun on the one side and the steady demand of the consumers on the other. Aside from the expansion of supra-regional transmission systems and storage power plants one instrument that has raised great hopes is the possibility of adapting demand to supply. These methods are known by the names of demand response (DR) or demand side management (DSM) and are at the core of the ''smart grid'' concept.

Enhanced nanoscale friction on fluorinated graphene.

Science.gov (United States)

Kwon, Sangku; Ko, Jae-Hyeon; Jeon, Ki-Joon; Kim, Yong-Hyun; Park, Jeong Young

2012-12-12

Atomically thin graphene is an ideal model system for studying nanoscale friction due to its intrinsic two-dimensional (2D) anisotropy. Furthermore, modulating its tribological properties could be an important milestone for graphene-based micro- and nanomechanical devices. Here, we report unexpectedly enhanced nanoscale friction on chemically modified graphene and a relevant theoretical analysis associated with flexural phonons. Ultrahigh vacuum friction force microscopy measurements show that nanoscale friction on the graphene surface increases by a factor of 6 after fluorination of the surface, while the adhesion force is slightly reduced. Density functional theory calculations show that the out-of-plane bending stiffness of graphene increases up to 4-fold after fluorination. Thus, the less compliant F-graphene exhibits more friction. This indicates that the mechanics of tip-to-graphene nanoscale friction would be characteristically different from that of conventional solid-on-solid contact and would be dominated by the out-of-plane bending stiffness of the chemically modified graphene. We propose that damping via flexural phonons could be a main source for frictional energy dissipation in 2D systems such as graphene.

Amontonian frictional behaviour of nanostructured surfaces.

Science.gov (United States)

Pilkington, Georgia A; Thormann, Esben; Claesson, Per M; Fuge, Gareth M; Fox, Oliver J L; Ashfold, Michael N R; Leese, Hannah; Mattia, Davide; Briscoe, Wuge H

2011-05-28

With nanotextured surfaces and interfaces increasingly being encountered in technological and biomedical applications, there is a need for a better understanding of frictional properties involving such surfaces. Here we report friction measurements of several nanostructured surfaces using an Atomic Force Microscope (AFM). These nanostructured surfaces provide well defined model systems on which we have tested the applicability of Amontons' laws of friction. Our results show that Amontonian behaviour is observed with each of the surfaces studied. However, no correlation has been found between measured friction and various surface roughness parameters such as average surface roughness (R(a)) and root mean squared (rms) roughness. Instead, we propose that the friction coefficient may be decomposed into two contributions, i.e., μ = μ(0) + μ(g), with the intrinsic friction coefficient μ(0) accounting for the chemical nature of the surfaces and the geometric friction coefficient μ(g) for the presence of nanotextures. We have found a possible correlation between μ(g) and the average local slope of the surface nanotextures. This journal is © the Owner Societies 2011

Static friction between rigid fractal surfaces.

Science.gov (United States)

Alonso-Marroquin, Fernando; Huang, Pengyu; Hanaor, Dorian A H; Flores-Johnson, E A; Proust, Gwénaëlle; Gan, Yixiang; Shen, Luming

2015-09-01

Using spheropolygon-based simulations and contact slope analysis, we investigate the effects of surface topography and atomic scale friction on the macroscopically observed friction between rigid blocks with fractal surface structures. From our mathematical derivation, the angle of macroscopic friction is the result of the sum of the angle of atomic friction and the slope angle between the contact surfaces. The latter is obtained from the determination of all possible contact slopes between the two surface profiles through an alternative signature function. Our theory is validated through numerical simulations of spheropolygons with fractal Koch surfaces and is applied to the description of frictional properties of Weierstrass-Mandelbrot surfaces. The agreement between simulations and theory suggests that for interpreting macroscopic frictional behavior, the descriptors of surface morphology should be defined from the signature function rather than from the slopes of the contacting surfaces.

Comparisons of friction models in bulk metal forming

DEFF Research Database (Denmark)

Tan, Xincai

2002-01-01

A friction model is one of the key input boundary conditions in finite element simulations. It is said that the friction model plays an important role in controlling the accuracy of necessary output results predicted. Among the various friction models, which one is of higher accuracy is still...... unknown and controversial. In this paper, finite element analyses applying five different friction models to experiments of upsetting of AA 6082 lubricated with four lubricants are presented. Frictional parameter values are determined by fitness of data of friction area ratio from finite element analysis...... to experimental results. It is found that calibration curves of the friction area ratio for all of the five chosen friction models used in the finite element simulation do fit the experimental results. Usually, calbration curves of the friction area ratio are more sensitive to friction at the tool...

Anticipating the friction coefficient of friction materials used in automobiles by means of machine learning without using a test instrument

OpenAIRE

TİMUR, Mustafa; AYDIN, Fatih

2013-01-01

The most important factor for designs in which friction materials are used is the coefficient of friction. The coefficient of friction has been determined taking such variants as velocity, temperature, and pressure into account, which arise from various factors in friction materials, and by analyzing the effects of these variants on friction materials. Many test instruments have been produced in order to determine the coefficient of friction. In this article, a study about the use ...

Demand Response With Micro-CHP Systems

NARCIS (Netherlands)

Houwing, M.; Negenborn, R.R.; De Schutter, B.

2011-01-01

With the increasing application of distributed energy resources and novel information technologies in the electricity infrastructure, innovative possibilities to incorporate the demand side more actively in power system operation are enabled. A promising, controllable, residential distributed

Structural Damping with Friction Beams

Directory of Open Access Journals (Sweden)

L. Gaul

2008-01-01

Full Text Available In the last several years, there has been increasing interest in the use of friction joints for enhancing damping in structures. The joints themselves are responsible for the major part of the energy dissipation in assembled structures. The dissipated work in a joint depends on both the applied normal force and the excitation force. For the case of a constant amplitude excitation force, there is an optimal normal force which maximizes the damping. A ‘passive’ approach would be employed in this instance. In most cases however, the excitation force, as well as the interface parameters such as the friction coefficient, normal pressure distribution, etc., are not constant. In these cases, a ‘semi-active’ approach, which implements an active varying normal force, is necessary. For the ‘passive’ and ‘semi-active’ approaches, the normal force has to be measured. Interestingly, since the normal force in a friction joint influences the local stiffness, the natural frequencies of the assembled structure can be tuned by adjusting the normal force. Experiments and simulations are performed for a simple laboratory structure consisting of two superposed beams with friction in the interface. Numerical simulation of the friction interface requires non-linear models. The response of the double beam system is simulated using a numerical algorithm programmed in MATLAB which models point-to-point friction with the Masing friction model. Numerical predictions and measurements of the double beam free vibration response are compared. A practical application is then described, in which a friction beam is used to damp the vibrations of the work piece table on a milling machine. The increased damping of the table reduces vibration amplitudes, which in turn results in enhanced surface quality of the machined parts, reduction in machine tool wear, and potentially higher feed rates. Optimal positioning of the friction beams is based on knowledge of the mode

Simulation of the Demand Side Management impacts: resolution enhancement of the input parameters at the local scale

International Nuclear Information System (INIS)

Imbert, P.

2011-01-01

Following the integrated energy planning paradigm in the 90's and the recent renewal of decentralized energy planning interests, Demand Side Management (DSM) actions are expected to take a significant role on energy planning activities in the future. Indeed the DSM actions represent a relevant option to achieve environmental and energy commitments or to alleviate some specific problems of electricity supply. DSM actions at the local scale at least in the French context is observed today. There is a need for appropriate methods and tools to assess the impacts of such MDE programs at local level. The local scale involves taking into account the specificities of the territories (physical, social, geographical, economical, institutional, etc.) The objective of this thesis is to improve the spatial resolution of input variables for the use in DSM action simulation tools. Based on a case study in France (PREMIO project: smart architecture for load management applied to a district) and an existing simulation tool we will study the impacts of this local experience to several municipalities. (author)

Tensile properties and strain-hardening behavior of double-sided arc welded and friction stir welded AZ31B magnesium alloy

International Nuclear Information System (INIS)

Chowdhury, S.M.; Chen, D.L.; Bhole, S.D.; Cao, X.; Powidajko, E.; Weckman, D.C.; Zhou, Y.

2010-01-01

Microstructures, tensile properties and work hardening behavior of double-sided arc welded (DSAWed) and friction stir welded (FSWed) AZ31B-H24 magnesium alloy sheet were studied at different strain rates. While the yield strength was higher, both the ultimate tensile strength and ductility were lower in the FSWed samples than in the DSAWed samples due to welding defects present at the bottom surface in the FSWed samples. Strain-hardening exponents were evaluated using the Hollomon relationship, the Ludwik equation and a modified equation. After welding, the strain-hardening exponents were nearly twice that of the base metal. The DSAWed samples exhibited stronger strain-hardening capacity due to the larger grain size coupled with the divorced eutectic structure containing β-Mg 17 Al 12 particles in the fusion zone, compared to the FSWed samples and base metal. Kocks-Mecking type plots were used to show strain-hardening stages. Stage III hardening occurred after yielding in both the base metal and the welded samples. At lower strains a higher strain-hardening rate was observed in the base metal, but it decreased rapidly with increasing net flow stress. At higher strains the strain-hardening rate of the welded samples became higher, because the recrystallized grains in the FSWed and the larger re-solidified grains coupled with β particles in the DSAWed provided more space to accommodate dislocation multiplication during plastic deformation. The strain-rate sensitivity evaluated via Lindholm's approach was observed to be higher in the base metal than in the welded samples.

FRICTION-BOON OR BANE IN ORTHODONTICS

Directory of Open Access Journals (Sweden)

Sameer

2015-11-01

Full Text Available OBJECTIVE: Most fixed appliance techniques involve some degree of sliding between brackets and arch wires. A sound knowledge of the various factors affecting the magnitude of friction is of paramount importance to the clinician. The present study was performed to evaluate and compare the frictional resistance and characteristics between self-ligating brackets and pre-adjusted edgewise brackets with different types of ligation. MATERIALS AND METHODS: Tidy's frictional test design was used to simulate retraction of tooth along with artificial saliva to simulate wet conditions in oral cavity. The jig with this assembly was mounted on the Instron machine with the cross head moving upwards at a speed of 5mm/min. The movable bracket was suspended from the load cell of the testing machine, while the jig was mounted on cross head of machine and the load cell readings were recorded on digital display. Following wires are used 0.016 HANT, 0.019X 0.025HANT, 0.019X 0.025 SS, 0.021X 0.025 SS wires are used. The brackets used were 0.022 slot Damon, 0.022 Smart clip and 0.022 slot MBT system. RESULTS: Self ligating brackets were shown to produce lesser friction when compared to the conventional brackets used with modules, and stainless steel ligatures. Damon self-ligating brackets produce a least friction of all the brackets used in the study. Stainless steel ligatures produced the least friction compared to elastomeric. CONCLUSION: Self ligation brackets produce lesser friction than the conventional brackets ligated with elastomeric modules and stainless steel ligature. Damon self-ligating brackets produce a least friction of all the brackets used in the study width of the bracket was also found to be directly proportional to the friction produced 0.0016HANT with elastomeric modules produce more friction due increase in flexibility of wire.

Nonlinear friction model for servo press simulation

Science.gov (United States)

Ma, Ninshu; Sugitomo, Nobuhiko; Kyuno, Takunori; Tamura, Shintaro; Naka, Tetsuo

2013-12-01

The friction coefficient was measured under an idealized condition for a pulse servo motion. The measured friction coefficient and its changing with both sliding distance and a pulse motion showed that the friction resistance can be reduced due to the re-lubrication during unloading process of the pulse servo motion. Based on the measured friction coefficient and its changes with sliding distance and re-lubrication of oil, a nonlinear friction model was developed. Using the newly developed the nonlinear friction model, a deep draw simulation was performed and the formability was evaluated. The results were compared with experimental ones and the effectiveness was verified.

Friction between silicon and diamond at the nanoscale

International Nuclear Information System (INIS)

Bai, Lichun; Srikanth, Narasimalu; Sha, Zhen-Dong; Pei, Qing-Xiang; Wang, Xu; Srolovitz, David J; Zhou, Kun

2015-01-01

This work investigates the nanoscale friction between diamond-structure silicon (Si) and diamond via molecular dynamics simulation. The interaction between the interfaces is considered as strong covalent bonds. The effects of load, sliding velocity, temperature and lattice orientation are investigated. Results show that the friction can be divided into two stages: the static friction and the kinetic friction. During the static friction stage, the load, lattice orientation and temperature dramatically affects the friction by changing the elastic limit of Si. Large elastic deformation is induced in the Si block, which eventually leads to the formation of a thin layer of amorphous Si near the Si-diamond interface and thus the beginning of the kinetic friction stage. During the kinetic friction stage, only temperature and velocity have an effect on the friction. The investigation of the microstructural evolution of Si demonstrated that the kinetic friction can be categorized into two modes (stick-slip and smooth sliding) depending on the temperature of the fracture region. (paper)

Nonmonotonicity of the Frictional Bimaterial Effect

Science.gov (United States)

Aldam, Michael; Xu, Shiqing; Brener, Efim A.; Ben-Zion, Yehuda; Bouchbinder, Eran

2017-10-01

Sliding along frictional interfaces separating dissimilar elastic materials is qualitatively different from sliding along interfaces separating identical materials due to the existence of an elastodynamic coupling between interfacial slip and normal stress perturbations in the former case. This bimaterial coupling has important implications for the dynamics of frictional interfaces, including their stability and rupture propagation along them. We show that while this bimaterial coupling is a monotonically increasing function of the bimaterial contrast, when it is coupled to interfacial shear stress perturbations through a friction law, various physical quantities exhibit a nonmonotonic dependence on the bimaterial contrast. In particular, we show that for a regularized Coulomb friction, the maximal growth rate of unstable interfacial perturbations of homogeneous sliding is a nonmonotonic function of the bimaterial contrast and provides analytic insight into the origin of this nonmonotonicity. We further show that for velocity-strengthening rate-and-state friction, the maximal growth rate of unstable interfacial perturbations of homogeneous sliding is also a nonmonotonic function of the bimaterial contrast. Results from simulations of dynamic rupture along a bimaterial interface with slip-weakening friction provide evidence that the theoretically predicted nonmonotonicity persists in nonsteady, transient frictional dynamics.

Surface Friction of Polyacrylamide Hydrogel Particles

Science.gov (United States)

Cuccia, Nicholas; Burton, Justin

Polyacrylamide hydrogel particles have recently become a popular system for modeling low-friction, granular materials near the jamming transition. Because a gel consists of a polymer network filled with solvent, its frictional behavior is often explained using a combination of hydrodynamic lubrication and polymer-surface interactions. As a result, the frictional coefficient can vary between 0.001 and 0.03 depending on several factors such as contact area, sliding velocity, normal force, and the gel surface chemistry. Most tribological measurements of hydrogels utilize two flat surfaces, where the contact area is not well-defined. We have built a custom, low-force tribometer to measure the single-contact frictional properties of spherical hydrogel particles on flat hydrogel surfaces under a variety of measurement conditions. At high velocities (> 1 cm/s), the friction coefficient depends linearly on velocity, but does not tend to zero at zero velocity. We also compare our measurements to solid particles (steel, glass, etc.) on hydrogel surfaces, which exhibit larger frictional forces, and show less dependence on velocity. A physical model for the friction which includes the lubrication layer between the deformed surfaces will be discussed. National Science Foundation Grant No. 1506446.

Evidence is growing on demand side of an oil peak

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-15

After years of continued growth, the number of miles driven by Americans started falling in December 2007. Not only are the number of miles driven falling, but as cars become more fuel efficient, they go further on fewer gallons - further reducing demand for gasoline. This trend is expected to accelerate. Drivers include, along with higher-efficiency cars, mass transit, reversal in urban sprawl, biofuels, and plug-in hybrid vehicles.

Demand-side bidding in Brazil; Leilao de eficiencia energetica no Brasil

Energy Technology Data Exchange (ETDEWEB)

Garcia, Agenor Gomes Pinto

2008-01-15

Since the New Electric Sector Model's conception an energy-efficiency auction, like the ones used to buy new energy, was considered. Recently, the subject has been frequently commented in studies and meetings. This thesis discuss the main issues about its implementation in Brazil and proposes a model for this. The first chapter shows the history and the Electric Sector actual frame, with emphasis in the energy planning, resumed after the 2001 electricity shortage, the structure created for the system expansion and analyses the results of the new energy's auctions until now. The second chapter studies how the energy-efficiency auction can affect agents and consumers and presents the auction theory, which is growing fast in recent years, and how it can be applied to the present case, showing the possible agents' behavior - ESCOs, larger consumers and appliance manufacturers, and its implication on the auction shape. The third chapter shows the past world experience in energy-efficiency selling - the USA DSB (demand-side bidding) and its actual results and an IEA (International Energy Agency) study about this market mechanism of energy-efficiency promotion. 'The DSB works but it's not simple' (Geller, 2006) sums up the main conclusion about DSB - it develops the M and V techniques and the ESCO industry, making energy-efficiency as good as new generation for system's growing. The fourth chapter presents a proposal for the energy-efficiency auction's implementation in Brazil - its opportunity, resources source, regional aspects and the steps to get there. The fifth chapter analyses the M and V 's techniques and shows examples of the four options for projects - the M and V is essential for the auction success and its development, on the other hand, can leverage the energy-efficiency market in Brazil. Finally, the last chapter concludes that the energy-efficiency auction can make a great contribution for energy efficiency and

Paediatric treadmill friction injuries.

Science.gov (United States)

Jeremijenko, Luke; Mott, Jonathan; Wallis, Belinda; Kimble, Roy

2009-05-01

The aim of this study was to report on the severity and incidence of children injured by treadmills and to promote the implementation of safety standards. This retrospective review of children with treadmill friction injuries was conducted in a single tertiary-level burns centre in Australia between January 1997 and June 2007. The study revealed 37 children who sustained paediatric treadmill friction injuries. This was a presentation of 1% of all burns. Thirty-three (90%) of the injuries occurred in the last 3.5 years (January 2004 to June 2007). The modal age was 3.2 years. Thirty-three (90%) injuries were either full thickness or deep partial friction burns. Eleven (30%) required split thickness skin grafts. Of those who became entrapped, 100% required skin grafting. This study found that paediatric treadmill friction injuries are severe and increasing in incidence. Australian standards should be developed, implemented and mandated to reduce this preventable and severe injury.

Gas desorption during friction of amorphous carbon films

International Nuclear Information System (INIS)

Rusanov, A; Fontaine, J; Martin, J-M; Mogne, T L; Nevshupa, R

2008-01-01

Gas desorption induced by friction of solids, i.e. tribodesorption, is one of the numerous physical and chemical phenomena, which arise during friction as result of thermal and structural activation of material in a friction zone. Tribodesorption of carbon oxides, hydrocarbons, and water vapours may lead to significant deterioration of ultra high vacuum conditions in modern technological equipment in electronic, optoelectronic industries. Therefore, knowledge of tribodesorption is crucial for the performance and lifetime of vacuum tribosystems. Diamond-like carbon (DLC) coatings are interesting materials for vacuum tribological systems due to their high wear resistance and low friction. Highly hydrogenated amorphous carbon (a-C:H) films are known to exhibit extremely low friction coefficient under high vacuum or inert environment, known as 'superlubricity' or 'superlow friction'. However, the superlow friction period is not always stable and then tends to spontaneous transition to high friction. It is supposed that hydrogen supply from the bulk to the surface is crucial for establishing and maintaining superlow friction. Thus, tribodesorption can serve also as a new technique to determine the role of gases in superlow friction mechanisms. Desorption of various a-C:H films, deposited by PECVD, ion-beam deposition and deposition using diode system, has been studied by means of ultra-high vacuum tribometer equipped with a mass spectrometer. It was found that in superlow friction period desorption rate was below the detection limit in the 0-85 mass range. However, transition from superlow friction to high friction was accompanied by desorption of various gases, mainly of H 2 and CH 4 . During friction transition, surfaces were heavily damaged. In experiments with DLC films with low hydrogen content tribodesorption was significant during the whole experiment, while low friction was not observed. From estimation of maximum surface temperature during sliding contact it

Fast demand response in support of the active distribution network

NARCIS (Netherlands)

MacDougall, P.; Heskes, P.; Crolla, P.; Burt, G.; Warmer, C.

2013-01-01

Demand side management has traditionally been investigated for "normal" operation services such as balancing and congestion management. However they potentially could be utilized for Distributed Network Operator (DNO) services. This paper investigates and validates the use of a supply and demand

Demand response policies for the implementation of smart grids

NARCIS (Netherlands)

Koliou, E.

2016-01-01

With the grasp of a smart grid in sight, discussions have shifted the focus of system security measures away from generation capacity; apart from modifying the supply side, demand may also be exploited to keep the system in balance. Specifically, Demand Response (DR) is the concept of consumer load

Microstructure and mechanical properties of friction stir welded SAF 2507 super duplex stainless steel

International Nuclear Information System (INIS)

Sato, Y.S.; Nelson, T.W.; Sterling, C.J.; Steel, R.J.; Pettersson, C.-O.

2005-01-01

The microstructure and mechanical properties of friction stir (FS) welded SAF 2507 super duplex stainless steel were examined. High-quality, full-penetration welds were successfully produced in the super duplex stainless steel by friction stir welding (FSW) using polycrystalline cubic boron nitride (PCBN) tool. The base material had a microstructure consisting of the ferrite matrix with austenite islands, but FSW refined grains of the ferrite and austenite phases in the stir zone through dynamic recrystallisation. Ferrite content was held between 50 and 60% throughout the weld. The smaller grain sizes of the ferrite and austenite phases caused increase in hardness and strength within the stir zone. Welded transverse tensile specimen failed near the border between the stir zone and TMAZ at the retreating side as the weld had roughly the same strengths as the base material

Demand side management in South Africa at industrial residence water heating systems using in line water heating methodology

International Nuclear Information System (INIS)

Rankin, R.; Rousseau, P.G.

2008-01-01

The South African electrical utility, ESKOM, currently focuses its demand side management (DSM) initiatives on controlling electrical load between 18:00 and 20:00 each day, which is the utility's peak demand period. Funding is provided to energy service companies (ESCo's) to implement projects that can achieve load shifting out of this period. This paper describes how an improved in line water heating concept developed in previous studies was implemented into several real life industrial sanitary water heating systems to obtain the DSM load shift required by ESKOM. Measurements from a selection of these plants are provided to illustrate the significant load reductions that are being achieved during 18:00-20:00. The measured results also show that the peak load reduction is achieved without adversely affecting the availability of sufficient hot water to the persons using the showering and washing facilities served by the water heating system. A very good correlation also exists between these measured results and simulations that were done beforehand to predict the DSM potential of the project. The in line water heater concept provides an improved solution for DSM at sanitary water heating systems due to the stratified manner in which hot water is supplied to the tanks. This provides an improved hot water supply to users when compared to conventional in tank heating systems, even with load shifting being done. It also improves the storage efficiency of a plant, thereby allowing the available storage capacity of a plant to be utilized to its full extent for load shifting purposes

Consumer-led demand side financing in health and education and its relevance for low and middle income countries.

Science.gov (United States)

Ensor, Tim

2004-01-01

There is increasing awareness that supply subsidies for health and education services often fail to benefit those that are most vulnerable in a community. This recognition has led to a growing interest in and experimentation with, consumer-led demand side financing systems (CL-DSF). These mechanisms place purchasing power in the hands of consumers to spend on specific services at accredited facilities. International evidence in education and health sectors suggest a limited success of CL-DSF in raising the consumption of key services amongst priority groups. There is also some evidence that vouchers can be used to improve targeting of vulnerable groups. There is very little positive evidence on the effect of CL-DSF on service quality as a consequence of greater competition. Location of services relative to population means that areas with more provider choice, particularly in the private sector, tend to be dominated by higher and middle-income households. Extending CL-DSF in low-income countries requires the development of capacity in administering these financing schemes and also accrediting providers. Schemes could focus primarily on fixed packages of key services aimed at easily identifiable groups. Piloting and robust evaluation is required to fill the evidence gap on the impact of these mechanisms. Extending demand financing to less predictable services, such as hospital coverage for the population, is likely to require the development of a voucher scheme to purchase insurance. This suggests an already developed insurance market and is unlikely to be appropriate in most low-income countries for some time.

Showing Area Matters: A Work of Friction

Science.gov (United States)

Van Domelen, David

2010-01-01

Typically, we teach the simplified friction equation of the form F[subscript s] = [mu][subscript s]N for static friction, where F[subscript s] is the maximum static friction, [mu][subscript s] is the coefficient of static friction, and "N" is the normal force pressing the surfaces together. However, this is a bit too simplified, and…

Microstructural variation through weld thickness and mechanical properties of peened friction stir welded 6061 aluminum alloy joints

Energy Technology Data Exchange (ETDEWEB)

Abdulstaar, Mustafa A., E-mail: mustafa.abdulstaar@gmail.com [Institute of Material Science and Engineering, Clausthal University of Technology, Agricolastr. 6, 38678 Clausthal-Zellerfeld (Germany); Al-Fadhalah, Khaled J. [Department of Mechanical Engineering, College of Engineering & Petroleum, Kuwait University, P.O. Box 5969, Safat 13060 (Kuwait); Wagner, Lothar [Institute of Material Science and Engineering, Clausthal University of Technology, Agricolastr. 6, 38678 Clausthal-Zellerfeld (Germany)

2017-04-15

The current study examined the effect of microstructure variation on the development of mechanical properties in friction stir welded joints of 6061-T6 aluminum alloy, which were subsequently processed by shot peening (SP). Following to FSW, fatigue specimens were extracted perpendicularly to the welding direction. Surface Skimming to 0.5 mm from crown and root sides of the joint was made and SP was later applied on the two sides using ceramic shots of two different Almen intensities of 0.18 mmA and 0.24 mmA. Microstructural examination by electron back scattered diffraction (EBSD) indicated variation in the grain refinement of the weld zone, with coarsest grains (5 μm) at the crown side and finest grains (2 μm) at the root side. Reduction of microhardness to 60 HV occurred in the weld zone for samples in FSW condition. Application of SP promoted significant strain hardening at the crown side, with Almen intensities of 0.24 mmA providing maximum increase in microhardness to 120 HV. On the contrary, only a maximum microhardness of 75 HV was obtained at the root side. The difference in strain hardening capability at the two sides was strongly dependent on grain size. The two Almen intensities produced similar distribution of compressive residual stresses in the subsurface regions that led to enhance the fatigue strength to the level of base metal for N ≥ 10{sup 5} cycles. Yet, the increase in fatigue strength was more pronounced with increasing Almen intensity to 0.24 mmA, demonstrating further enhancement by strain hardening. - Highlights: • Grain refinement was observed after friction stir welding of AA 6061-T6. • Reduction in microhardness and fatigue strength were obtained after welding. • Variation in grain refinement led to different hardening behavior after peening. • Shot peening induced beneficial compressive residual stresses. • Shot peening and surface skimming markedly improved the fatigue performance.

Joint properties of dissimilar Al6061-T6 aluminum alloy/Ti–6%Al–4%V titanium alloy by gas tungsten arc welding assisted hybrid friction stir welding

International Nuclear Information System (INIS)

Bang, HanSur; Bang, HeeSeon; Song, HyunJong; Joo, SungMin

2013-01-01

Highlights: • Hybrid friction stir welding for Al alloy and Ti alloy joint has been carried out. • Mechanical strength of dissimilar joint by HFSW and FSW has been compared. • Microstructure of dissimilar joint by HFSW and FSW has been compared. - Abstract: Hybrid friction stir butt welding of Al6061-T6 aluminum alloy plate to Ti–6%Al–4%V titanium alloy plate with satisfactory acceptable joint strength was successfully achieved using preceding gas tungsten arc welding (GTAW) preheating heat source of the Ti alloy plate surface. Hybrid friction stir welding (HFSW) joints were welded completely without any unwelded zone resulting from smooth material flow by equally distributed temperature both in Al alloy side and Ti alloy side using GTAW assistance for preheating the Ti alloy plate unlike friction stir welding (FSW) joints. The ultimate tensile strength was approximately 91% in HFSW welds by that of the Al alloy base metal, which was 24% higher than that of FSW welds without GTAW under same welding condition. Notably, it was found that elongation in HFSW welds increased significantly compared with that of FSW welds, which resulted in improved joint strength. The ductile fracture was the main fracture mode in tensile test of HFSW welds

Comparing the physical demands of friendly matches and small-sided games in semiprofessional soccer players.

Science.gov (United States)

Casamichana, David; Castellano, Julen; Castagna, Carlo

2012-03-01

This study compared the physical demands of friendly matches (FMs) and small-sided games (SGs) in semiprofessional soccer players by means of global positioning system technology. Twenty-seven semiprofessional soccer players were monitored during 7 FMs and 9 sessions involving different SGs. Their physical profile was described on the basis of 20 variables related to distances and frequencies at different running speeds, the number of accelerations, and through global indicators of workload such as the work:rest ratio, player workload, and the exertion index. Results showed significant differences (p FM); the distribution of the distance covered in the speed zones 7.0-12.9 km·h(-1) (SG > FM) and >21 km·h(-1) (FM > SG); the distribution of time spent in certain speed zones (FM > SG: 0.0-6.9 and >21 km·h(-1); FM > SG: 7.0-12.9 km·h(-1)). More sprints per hour of play were performed during FMs, with greater mean durations and distances, greater maximum durations and distances, and a greater frequency per hour of play for sprints of 10-40 and >40 m (p < 0.01). The frequency of repeated high-intensity efforts was higher during FM (p < 0.01). The results show that coaches and strength and conditioning professionals should consider FMs during their training routine to foster specific adaptations in the domain of high-intensity effort.

[Friction: self-ligating brackets].

Science.gov (United States)

Thermac, Guilhem; Morgon, Laurent; Godeneche, Julien

2008-12-01

The manufacturers of self-ligating brackets advertise a reduction of the friction engendered between the wire and the bracket, which is an essential parameter for treatment's speed and comfort. We have compared the friction obtained with four types of self-ligating brackets - In-Ovation R, Damon 3, Smart Clip and Quick - with that of a standard bracket Omniarch associated with an elastomeric ligature. All bracket were tested on a bench of traction with three types of wires: steel .019"x.025", TMA .019"x.025" and NEO sentalloy F300 .020"x.020". The results confirm a clear friction reduction for all tested wire.

Effect of fin pitch and number of tube rows on the air side performance of herringbone wavy fin and tube heat exchangers

International Nuclear Information System (INIS)

Wongwises, Somchai; Chokeman, Yutasak

2005-01-01

An experimental study is conducted to investigate the effects of a fin pitch and number of tube rows on the air side performance of fin and tube heat exchangers having herringbone wavy fin configuration at various fin thicknesses. A total of 10 samples of fin and tube heat exchanger with a tube outside diameter of 9.53mm, transverse tube pitch of 25.4mm and longitudinal tube pitch of 19.05mm, having various fin pitches, number of tube rows and fin thicknesses, are tested in a well insulated open wind tunnel. The heat exchangers are made from aluminium plate finned, copper tube. Ambient air is used as a working fluid in the air side while hot water is used for the tube side. The results are presented as the variation of the Colburn factor and the friction factor with the Reynolds number based on the fin collar outside diameter (Re D c ). The experimental results reveal that the fin pitch has an insignificant effect on the heat transfer characteristic. The friction factor increases with increasing fin pitch when Re D c >2500, approximately. The Colburn factor and the friction factor decrease with increasing number of tube rows when Re D c <4000, approximately. These results remain the same when the fin thickness is changed

Three-dimensional friction measurement during hip simulation.

Directory of Open Access Journals (Sweden)

Robert Sonntag

Full Text Available Wear of total hip replacements has been the focus of many studies. However, frictional effects, such as high loading on intramodular connections or the interface to the bone, as well as friction associated squeaking have recently increased interest about the amount of friction that is generated during daily activities. The aim of this study was thus to establish and validate a three-dimensional friction setup under standardized conditions.A standard hip simulator was modified to allow for high precision measurements of small frictional effects in the hip during three-dimensional hip articulation. The setup was verified by an ideal hydrostatic bearing and validated with a static-load physical pendulum and an extension-flexion rotation with a dynamic load profile. Additionally, a pendulum model was proposed for screening measurement of frictional effects based on the damping behavior of the angular oscillation without the need for any force/moment transducer. Finally, three-dimensional friction measurements have been realized for ceramic-on-polyethylene bearings of three different sizes (28, 36 and 40 mm.A precision of less than 0.2 Nm during three-dimensional friction measurements was reported, while increased frictional torque (resultant as well as taper torque was measured for larger head diameters. These effects have been confirmed by simple pendulum tests and the theoretical model. A comparison with current literature about friction measurements is presented.This investigation of friction is able to provide more information about a field that has been dominated by the reduction of wear. It should be considered in future pre-clinical testing protocols given by international organizations of standardization.

Challenges of using model predictive control for active demand side management

DEFF Research Database (Denmark)

Zong, Yi; You, Shi; Hu, Junjie

2015-01-01

When there is a high penetration of renewables in the power system, it requires coordinated management of large numbers of distributed and demand response resources, intermittent resources to maintain the grid reliability and improve operational economics. This paper presents a hierarchical...... and dynamic power price signals....

Simulation of demand side participation in Spanish short term electricity markets

International Nuclear Information System (INIS)

Valencia-Salazar, I.; Alvarez, C.; Escriva-Escriva, G.; Alcazar-Ortega, M.

2011-01-01

Highlights: → Benefits from customer active participation can be obtained with a proper generation of bids and offers. → Simulation of Spanish customers' participation is shown in daily, intra-daily and balancing markets. → Market efficiency and economics profits arise in balancing markets by using customer load reductions. → Real market prices and real customers' consumptions profiles are used in the simulations. -- Abstract: Demand response resources management is one of the most investigated solutions oriented to improve the efficiency in electricity markets. In this paper, the capability of customers to participate in short term markets is analyzed. An available methodology to analyze the daily and monthly energy consumptions of large customers is used to create energy offers and bids. This allows customers to participate in energy markets in order to buy, as first step, the usual electricity consumption and, additionally, to offer demand reductions in the short term electricity markets. Additionally, this paper shows the customer potential to participate in the Spanish electricity markets.

Development of a Constitutive Friction Law based on the Frictional Interaction of Rough Surfaces

Directory of Open Access Journals (Sweden)

F. Beyer

2015-12-01

Full Text Available Friction has a considerable impact in metal forming. This is in particular true for sheet-bulk metal-forming (SBMF in which local highly varying contact loads occur. A constitutive friction law suited to the needs of SBMF is necessary, if numerical investigations in SBMF are performed. The identification of the friction due to adhesion and ploughing is carried out with an elasto-plastic half-space model. The normal contact is verified for a broad range of normal loads. In addition, the model is used for the characterization of the occurring shear stress. Ploughing is determined by the work which is necessary to plastically deform the surface asperities of the new area that gets into contact during sliding. Furthermore, the surface patches of common half-space models are aligned orthogonally to the direction in which the surfaces approach when normal contact occurs. For a better reflection of the original surfaces, the element patches become inclined. This leads to a geometric share of lateral forces which also contribute to friction. Based on these effects, a friction law is derived which is able to predict the contact conditions especially for SBMF.

Predictive Control of a Domestic Freezer for Real-Time Demand Response Applications

NARCIS (Netherlands)

Baghina, N.G.; Lampropoulos, I.; Asare-Bediako, B.; Kling, W.L.; Ribeiro, P.F.

2012-01-01

Demand side management and demand response aim to maximize the efficiency of the electricity delivery process by exploiting the flexibility of customers. At residential level, demand response can be applied only to a limited number of appliances, through load management, due to user intervention or

A thermodynamic model of sliding friction

Directory of Open Access Journals (Sweden)

Lasse Makkonen

2012-03-01

Full Text Available A first principles thermodynamic model of sliding friction is derived. The model predictions are in agreement with the observed friction laws both in macro- and nanoscale. When applied to calculating the friction coefficient the model provides a quantitative agreement with recent atomic force microscopy measurements on a number of materials.

Friction torque of wind-turbine pitch bearings – comparison of experimental results with available models

Directory of Open Access Journals (Sweden)

M. Stammler

2018-03-01

Full Text Available Pitch bearings of wind turbines are large, grease-lubricated rolling bearings that connect the rotor blades with the rotor hub. They are used to turn the rotor blades to control the power output and/or structural loads of the turbine. Common actuators turning the blades are hydraulic cylinders or electrical motor–gearbox combinations. In order to design pitch actuator systems that are able to turn the blades reliably without imposing an excessive power demand, it is necessary to predict the friction torque of pitch bearings for different operating conditions. In this paper, the results of torque measurements under load are presented and compared to results obtained using different calculation models. The results of this comparison indicate the various sources of friction that should be taken into account for a reliable calculation model.

Slow rupture of frictional interfaces

Science.gov (United States)

Bar Sinai, Yohai; Brener, Efim A.; Bouchbinder, Eran

2012-02-01

The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not completely understood. We show that slow rupture is an intrinsic and robust property of simple non-monotonic rate-and-state friction laws. It is associated with a new velocity scale cmin, determined by the friction law, below which steady state rupture cannot propagate. We further show that rupture can occur in a continuum of states, spanning a wide range of velocities from cmin to elastic wave-speeds, and predict different properties for slow rupture and ordinary fast rupture. Our results are qualitatively consistent with recent high-resolution laboratory experiments and may provide a theoretical framework for understanding slow rupture phenomena along frictional interfaces.

Addressing Energy Demand through Demand Response. International Experiences and Practices

Energy Technology Data Exchange (ETDEWEB)

Shen, Bo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ghatikar, Girish [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ni, Chun Chun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dudley, Junqiao [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Martin, Phil [Enernoc, Inc., Boston, MA (United States); Wikler, Greg

2012-06-01

Demand response (DR) is a load management tool which provides a cost-effective alternative to traditional supply-side solutions to address the growing demand during times of peak electrical load. According to the US Department of Energy (DOE), demand response reflects “changes in electric usage by end-use customers from their normal consumption patterns in response to changes in the price of electricity over time, or to incentive payments designed to induce lower electricity use at times of high wholesale market prices or when system reliability is jeopardized.” 1 The California Energy Commission (CEC) defines DR as “a reduction in customers’ electricity consumption over a given time interval relative to what would otherwise occur in response to a price signal, other financial incentives, or a reliability signal.” 2 This latter definition is perhaps most reflective of how DR is understood and implemented today in countries such as the US, Canada, and Australia where DR is primarily a dispatchable resource responding to signals from utilities, grid operators, and/or load aggregators (or DR providers).

On Heels and Toes: How Ants Climb with Adhesive Pads and Tarsal Friction Hair Arrays.

Directory of Open Access Journals (Sweden)

Thomas Endlein

Full Text Available Ants are able to climb effortlessly on vertical and inverted smooth surfaces. When climbing, their feet touch the substrate not only with their pretarsal adhesive pads but also with dense arrays of fine hairs on the ventral side of the 3rd and 4th tarsal segments. To understand what role these different attachment structures play during locomotion, we analysed leg kinematics and recorded single-leg ground reaction forces in Weaver ants (Oecophylla smaragdina climbing vertically on a smooth glass substrate. We found that the ants engaged different attachment structures depending on whether their feet were above or below their Centre of Mass (CoM. Legs above the CoM pulled and engaged the arolia ('toes', whereas legs below the CoM pushed with the 3rd and 4th tarsomeres ('heels' in surface contact. Legs above the CoM carried a significantly larger proportion of the body weight than legs below the CoM. Force measurements on individual ant tarsi showed that friction increased with normal load as a result of the bending and increasing side contact of the tarsal hairs. On a rough sandpaper substrate, the tarsal hairs generated higher friction forces in the pushing than in the pulling direction, whereas the reverse effect was found on the smooth substrate. When the tarsal hairs were pushed, buckling was observed for forces exceeding the shear forces found in climbing ants. Adhesion forces were small but not negligible, and higher on the smooth substrate. Our results indicate that the dense tarsal hair arrays produce friction forces when pressed against the substrate, and help the ants to push outwards during horizontal and vertical walking.

On Heels and Toes: How Ants Climb with Adhesive Pads and Tarsal Friction Hair Arrays.

Science.gov (United States)

Endlein, Thomas; Federle, Walter

2015-01-01

Ants are able to climb effortlessly on vertical and inverted smooth surfaces. When climbing, their feet touch the substrate not only with their pretarsal adhesive pads but also with dense arrays of fine hairs on the ventral side of the 3rd and 4th tarsal segments. To understand what role these different attachment structures play during locomotion, we analysed leg kinematics and recorded single-leg ground reaction forces in Weaver ants (Oecophylla smaragdina) climbing vertically on a smooth glass substrate. We found that the ants engaged different attachment structures depending on whether their feet were above or below their Centre of Mass (CoM). Legs above the CoM pulled and engaged the arolia ('toes'), whereas legs below the CoM pushed with the 3rd and 4th tarsomeres ('heels') in surface contact. Legs above the CoM carried a significantly larger proportion of the body weight than legs below the CoM. Force measurements on individual ant tarsi showed that friction increased with normal load as a result of the bending and increasing side contact of the tarsal hairs. On a rough sandpaper substrate, the tarsal hairs generated higher friction forces in the pushing than in the pulling direction, whereas the reverse effect was found on the smooth substrate. When the tarsal hairs were pushed, buckling was observed for forces exceeding the shear forces found in climbing ants. Adhesion forces were small but not negligible, and higher on the smooth substrate. Our results indicate that the dense tarsal hair arrays produce friction forces when pressed against the substrate, and help the ants to push outwards during horizontal and vertical walking.

The inhomogeneous microstructure and deformation of similar and dissimilar Al-Zn containing Mg friction stir welds

Science.gov (United States)

Hiscocks, Jessica

The magnesium-based aluminum-zinc alloys have excellent stiffness to weight ratios, and may be combined by friction stir welding to expand the possible applications. The high aluminum alloy AZ80 in particular has the advantage of being relatively stiff but still extrudable. However limited friction stir welding research is available for this alloy and extrapolation from the extensive work in aluminum alloys is impractical due differences in precipitation behaviour, and magnesium's high plastic anisotropy and tendency to form strong textures during friction stir welding. This work investigates the correlations between local friction stir welded microstructures, textures, residual strains, and the local deformation behaviour based on strain mapping during tensile tests. Covering bead-on-plate and butt configurations, joining of similar and dissimilar materials, and a range of processing conditions, many findings of interest for deformation modelling and industrial applications are presented. Synchrotron x-ray diffraction study of an entire friction stir weld was used to determine texture, residual strain and dislocation density data from a single experiment. A number of unique findings were made, mainly related to the asymmetric distribution of properties both between sides of the weld and through the depth. Particularly in the case of strain measurements, features not detectable at coarser measurement spacing or by line scan are presented and compared for multiple processing conditions. Investigation of the longitudinal material flow during welding showed that even when periodicity in grain size, precipitate distribution, or texture was not observed, periodic changes in texture intensity resulting from compaction of material behind the tool were present, providing evidence that movement of nugget material remained periodic. Strain localisation and fracture behaviour were found to be completely different between good quality similar and dissimilar friction stir welds

Preload, Coefficient of Friction, and Thread Friction in an Implant-Abutment-Screw Complex.

Science.gov (United States)

Wentaschek, Stefan; Tomalla, Sven; Schmidtmann, Irene; Lehmann, Karl Martin

To examine the screw preload, coefficient of friction (COF), and tightening torque needed to overcome the thread friction of an implant-abutment-screw complex. In a customized load frame, 25 new implant-abutment-screw complexes including uncoated titanium alloy screws were torqued and untorqued 10 times each, applying 25 Ncm. Mean preload values decreased significantly from 209.8 N to 129.5 N according to the number of repetitions. The overall COF increased correspondingly. There was no comparable trend for the thread friction component. These results suggest that the application of a used implant-abutment-screw complex may be unfavorable for obtaining optimal screw preload.