888 resultados para Energy Consumption Forecasting


Relevância:

80.00% 80.00%

Publicador:

Resumo:

This doctoral dissertation explores the contribution of environmental management practices, the so-called clean development mechanism (CDM) projects, and foreign direct investment (FDI) in achieving sustainable development in developing countries, particularly in Sub- Saharan Africa. Because the climate change caused by greenhouse gas emissions is one of the most serious global environmental challenges, the main focus is on the causal links between carbon dioxide (CO2) emissions, energy consumption, and economic development in Sub-Saharan Africa. In addition, the dissertation investigates the factors that have affected the distribution of CDM projects in developing countries and the relationships between FDI and other macroeconomic variables of interest. The main contribution of the dissertation is empirical. One of the publications uses crosssectional data and Tobit and Poisson regressions. Three of the studies use time-series data and vector autoregressive and vector error correction models, while two publications use panel data and panel data estimation methods. One of the publications uses thus both timeseries and panel data. The concept of Granger causality is utilized in four of the publications. The results indicate that there are significant differences in the Granger causality relationships between CO2 emissions, energy consumption, economic growth, and FDI in different countries. It appears also that the causality relationships change over time. Furthermore, the results support the environmental Kuznets curve hypothesis but only for some of the countries. As to CDM activities, past emission levels, institutional quality, and the size of the host country appear to be among the significant determinants of the distribution of CDM projects. FDI and exports are also found to be significant determinants of economic growth.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Talotekniikan alalla valaistusmuutoksissa LED-valaistus on nykypäivää. Valaistuksen käyttöominaisuudet ja hyödyt tekevät siitä perustellun valinnan myös suurissa kohteissa. Näistä laajemmista valaistuksen muutoksista ja niiden vaikutuksista sähkön laatuun ei ole yleisesti mittaustietoa. Tämä tutkimus perustui sähkön laadun käytännön mittauksiin valaistusmuutoksessa, jossa elohopeahöyrylampuilla toteutettu valaistus vaihdettiin LED-valaistukseen hypermarketin pysäköintihallissa. Valaistusjärjestelmän muutoksen vaikutusta sähkön laatuun tutkittiin vertailemalla mittaustuloksia vanhan ja uuden järjestelmän välillä. Tutkimuksen tarkoituksena oli osoittaa miten LED-valaistukseen siirtyminen vaikuttaa sähkön laatuun valitussa tutkimuskohteessa. Tutkimuksessa tuotettu tieto on hyödynnettävissä vastaavissa kohteissa LED-valaistukseen siirryttäessä sekä valaistuksen käyttöönoton suunnittelussa ja toteuttamisessa. Tutkimuksen tuloksia voidaan hyödyntää myös kustannusten arvioimisessa valaistavan tilan sähkönkulutuksen osalta. Tutkimus toteutettiin käyttämällä triangulaatiomenetelmää eli teemahaastattelulla, kirjallisuuskatsauksella ja käytännön mittauksilla. Näiden menetelmien tulokset tukivat tutkimukselle asetettuja hypoteeseja. Valitulla tutkimusmenetelmällä saatiin selville, että LED-valaistukseen siirtymisellä ei ollut heikentäviä vaikutuksia sähkön laatuun tutkitun kohteen valaistusjärjestelmässä. Toisaalta positiivisina vaikutuksina huomioitiin muun muassa merkittävä energian säästö, virran harmonisten häiriöiden väheneminen sekä kokonaistehokertoimen parantuminen.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Electrical machine drives are the most electrical energy-consuming systems worldwide. The largest proportion of drives is found in industrial applications. There are, however many other applications that are also based on the use of electrical machines, because they have a relatively high efficiency, a low noise level, and do not produce local pollution. Electrical machines can be classified into several categories. One of the most commonly used electrical machine types (especially in the industry) is induction motors, also known as asynchronous machines. They have a mature production process and a robust rotor construction. However, in the world pursuing higher energy efficiency with reasonable investments not every application receives the advantage of using this type of motor drives. The main drawback of induction motors is the fact that they need slipcaused and thus loss-generating current in the rotor, and additional stator current for magnetic field production along with the torque-producing current. This can reduce the electric motor drive efficiency, especially in low-speed, low-power applications. Often, when high torque density is required together with low losses, it is desirable to apply permanent magnet technology, because in this case there is no need to use current to produce the basic excitation of the machine. This promotes the effectiveness of copper use in the stator, and further, there is no rotor current in these machines. Again, if permanent magnets with a high remanent flux density are used, the air gap flux density can be higher than in conventional induction motors. These advantages have raised the popularity of PMSMs in some challenging applications, such as hybrid electric vehicles (HEV), wind turbines, and home appliances. Usually, a correctly designed PMSM has a higher efficiency and consequently lower losses than its induction machine counterparts. Therefore, the use of these electrical machines reduces the energy consumption of the whole system to some extent, which can provide good motivation to apply permanent magnet technology to electrical machines. However, the cost of high performance rare earth permanent magnets in these machines may not be affordable in many industrial applications, because the tight competition between the manufacturers dictates the rules of low-cost and highly robust solutions, where asynchronous machines seem to be more feasible at the moment. Two main electromagnetic components of an electrical machine are the stator and the rotor. In the case of a conventional radial flux PMSM, the stator contains magnetic circuit lamination and stator winding, and the rotor consists of rotor steel (laminated or solid) and permanent magnets. The lamination itself does not significantly influence the total cost of the machine, even though it can considerably increase the construction complexity, as it requires a special assembly arrangement. However, thin metal sheet processing methods are very effective and economically feasible. Therefore, the cost of the machine is mainly affected by the stator winding and the permanent magnets. The work proposed in this doctoral dissertation comprises a description and analysis of two approaches of PMSM cost reduction: one on the rotor side and the other on the stator side. The first approach on the rotor side includes the use of low-cost and abundant ferrite magnets together with a tooth-coil winding topology and an outer rotor construction. The second approach on the stator side exploits the use of a modular stator structure instead of a monolithic one. PMSMs with the proposed structures were thoroughly analysed by finite element method based tools (FEM). It was found out that by implementing the described principles, some favourable characteristics of the machine (mainly concerning the machine size) will inevitable be compromised. However, the main target of the proposed approaches is not to compete with conventional rare earth PMSMs, but to reduce the price at which they can be implemented in industrial applications, keeping their dimensions at the same level or lower than those of a typical electrical machine used in the industry at the moment. The measurement results of the prototypes show that the main performance characteristics of these machines are at an acceptable level. It is shown that with certain specific actions it is possible to achieve a desirable efficiency level of the machine with the proposed cost reduction methods.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

In anurans, changes in ambient temperature influence body temperature and, therefore, energy consumption. These changes ultimately affect energy supply and, consequently, heart rate (HR). Typically, anurans living in different thermal environments have different thermal sensitivities, and these cannot be distinguished by changes in HR. We hypothesized that Rhinella jimi (a toad from a xeric environment that lives in a wide range of temperatures) would have a lower thermal sensitivity regarding cardiac control than R. icterica (originally from a tropical forest environment with a more restricted range of ambient temperatures). Thermal sensitivity was assessed by comparing animals housed at 15° and 25°C. Cardiac control was estimated by heart rate variability (HRV) and heart rate complexity (HRC). Differences in HRV between the two temperatures were not significant (P=0.214 for R. icterica and P=0.328 for R. jimi), whereas HRC differences were. All specimens but one R. jimi had a lower HRC at 15°C (all P<0.01). These results indicate that R. jimi has a lower thermal sensitivity and that cardiac control is not completely dependent on the thermal environment because HRC was not consistently different between temperatures in all R. jimi specimens. This result indicates a lack of evolutive trade-offs among temperatures given that heart rate control at 25°C is potentially not a constraint to heart rate control at 15°C.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

In this work the separation of multicomponent mixtures in counter-current columns with supercritical carbon dioxide has been investigated using a process design methodology. First the separation task must be defined, then phase equilibria experiments are carried out, and the data obtained are correlated with thermodynamic models or empirical functions. Mutual solubilities, Ki-values, and separation factors aij are determined. Based on this data possible operating conditions for further extraction experiments can be determined. Separation analysis using graphical methods are performed to optimize the process parameters. Hydrodynamic experiments are carried out to determine the flow capacity diagram. Extraction experiments in laboratory scale are planned and carried out in order to determine HETP values, to validate the simulation results, and to provide new materials for additional phase equilibria experiments, needed to determine the dependence of separation factors on concetration. Numerical simulation of the separation process and auxiliary systems is carried out to optimize the number of stages, solvent-to-feed ratio, product purity, yield, and energy consumption. Scale-up and cost analysis close the process design. The separation of palmitic acid and (oleic+linoleic) acids from PFAD-Palm Fatty Acids Distillates was used as a case study.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The whole research of the current Master Thesis project is related to Big Data transfer over Parallel Data Link and my main objective is to assist the Saint-Petersburg National Research University ITMO research team to accomplish this project and apply Green IT methods for the data transfer system. The goal of the team is to transfer Big Data by using parallel data links with SDN Openflow approach. My task as a team member was to compare existing data transfer applications in case to verify which results the highest data transfer speed in which occasions and explain the reasons. In the context of this thesis work a comparison between 5 different utilities was done, which including Fast Data Transfer (FDT), BBCP, BBFTP, GridFTP, and FTS3. A number of scripts where developed which consist of creating random binary data to be incompressible to have fair comparison between utilities, execute the Utilities with specified parameters, create log files, results, system parameters, and plot graphs to compare the results. Transferring such an enormous variety of data can take a long time, and hence, the necessity appears to reduce the energy consumption to make them greener. In the context of Green IT approach, our team used Cloud Computing infrastructure called OpenStack. It’s more efficient to allocated specific amount of hardware resources to test different scenarios rather than using the whole resources from our testbed. Testing our implementation with OpenStack infrastructure results that the virtual channel does not consist of any traffic and we can achieve the highest possible throughput. After receiving the final results we are in place to identify which utilities produce faster data transfer in different scenarios with specific TCP parameters and we can use them in real network data links.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

In Mobile Ad-hoc Networks (MANET) the participating nodes have several roles such as sender, receiver and router. Hence there is a lot of energy consumed by the nodes for the normal working of the network since each node has many different roles. Also in MANET the nodes keep moving constantly and this in turn consumes a lot of energy. Since battery capacity of these nodes is limited it fails to fulfil the high demand of energy. The scarcity of energy makes the energy conservation in mobile ad-hoc networks an important concern. There is several research carried out on the energy consumption of mobile ad-hoc networks these days. Some of this research suggests sleep mode, transmission power control, load balancing etc. In this thesis, we are comparing various proposed energy efficient models for some of the ad-hoc protocols. We compare different energy efficient models for Optimised Linked State Algorithm (OLSR) and Ad-hoc On Demand Distance Vector (AODV). The routing protocols are compared for different parameters such as average remaining energy, number of nodes alive, payload data received and performance with different mobility speed. The simulation results helps in benchmarking the various energy efficient routing models for OLSR and AODV protocols. The benchmarking of the routing protocols can be based on many factors but this thesis concentrates on benchmarking the MANET routing protocols mainly based on the energy efficiency and increased network lifetime.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

With the new age of Internet of Things (IoT), object of everyday such as mobile smart devices start to be equipped with cheap sensors and low energy wireless communication capability. Nowadays mobile smart devices (phones, tablets) have become an ubiquitous device with everyone having access to at least one device. There is an opportunity to build innovative applications and services by exploiting these devices’ untapped rechargeable energy, sensing and processing capabilities. In this thesis, we propose, develop, implement and evaluate LoadIoT a peer-to-peer load balancing scheme that can distribute tasks among plethora of mobile smart devices in the IoT world. We develop and demonstrate an android-based proof of concept load-balancing application. We also present a model of the system which is used to validate the efficiency of the load balancing approach under varying application scenarios. Load balancing concepts can be apply to IoT scenario linked to smart devices. It is able to reduce the traffic send to the Cloud and the energy consumption of the devices. The data acquired from the experimental outcomes enable us to determine the feasibility and cost-effectiveness of a load balanced P2P smart phone-based applications.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The aim of the present study was to precool cauliflower using forced-air, vacuum and high and low flow hydro cooling methods. The weight of the precooled cauliflower heads (5000±5 g) was measured before they were placed in standard plastic crates. Cauliflower heads, whose initial temperature was 23.5 ± 0.5 ºC, were cooled until the temperature reached at 1 ºC. During the precooling process, time-dependent temperature and energy consumption were measured, and during vacuum precooling, the decreasing pressure values were recorded, and a curve of time-dependent pressure decrease (vacuum) was built. The most suitable cooling method to precool cauliflower in terms of cooling time and energy consumption was vacuum, followed by the high and low flow hydro and forced-air precooling methods, respectively. The highest weight loss was observed in the vacuum precooling method, followed by the forced-air method. However, there was an increase in the weight of the cauliflower heads in the high and low flow hydro precooling method. The best colour and hardness values were found in the vacuum precooling method. Among all methods tested, the most suitable method to precool cauliflower in terms of cooling and quality parameters was the vacuum precooling method.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Suomen energialähteiden käyttö on pysynyt likimain samana viime vuosikymmenen aikana. Uusiutuvien energialähteiden käyttö (tuulivoima, aurinkovoima, biopolttoaineet) on lisääntynyt ja fossiilisten energialähteiden käyttö vähentynyt. Energian kokonaiskulutus ja lämmönkulutus on vuosikymmenen aikana laskenut hieman ja sähkönkulutus on lisääntynyt lisääntyvän infrastruktuurin myötä. Suomen kantaverkko ei ole vuosikymmenen aikana kokenut suuria muutoksia. Suomi kuuluu osana pohjoismaiden yhteisiä sähkömarkkinoita, joissa vallitsee vapaa kilpailu. Suomen energiajärjestelmän sähköntuotto on tällä hetkellä varsin tuontipainotteinen ja Suomi ei ole pystynyt vuosikymmenen aikana vastaamaan sähkön kysyntään, mikä tarkoittaa sähkön tuonnin lisääntymistä. Lämmöntuotanto ja -kulutus ovat pysyneet vuosikymmenen aikana likimain ennallaan. Lähitulevaisuudessa Suomen energiaomavaraisuus nousee ja Suomi voi jopa vuonna 2050 olla jo sähkön nettoviejä ja myös energiajärjestelmän aiheuttamat kokonaispäästöjä alenevat radikaalisti. Liikenne sähköistyy ja älykkäät sähköverkot tekevät tuloaan. Tässä työssä tutustutaan Suomen nykyiseen energiajärjestelmään, tehdään katsaus tulevaisuuteen ja vertaillaan Suomen energiajärjestelmää kansainvälisesti.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Diplomityön tavoitteena on selvittää sinfoniaorkesterin toiminnan merkittävimmät kasvihuonekaasupäästölähteet sekä kuinka kasvihuonekaasupäästöjä voidaan vähentää ja/tai kompensoida niin, että voidaan saavuttaa hiilineutraalius. Tavoitteena on myös tutkia sinfoniaorkesterin vaikutusmahdollisuudet sen sidosryhmiin. Tuloksia tarkastellaan myös globaalissa mittakaavassa, jolloin nähdään millainen vaikutus sinfoniaorkestereiden hiilineutraaliudella olisi ilmastonmuutoksen hillinnässä. Diplomityössä esitetään ensin hiilijalanjälkilaskentaa ja musiikkiteollisuutta yleisesti, jonka jälkeen selvitetään case-tutkimuksena Sinfonia Lahden hiilijalanjälki. Hiilijalanjälkilaskenta perustuu Sinfonia Lahden antamiin tietoihin, minkä lisäksi hyödynnetään diplomityön yhteydessä tehtyjen kyselyjen tuloksia. Kyselyjen tarkoituksena on selvittää sekä Sinfonia Lahden henkilöstön että yleisön matkustustottumuksia. Sinfonia Lahden henkilöstölle järjestettiin myös workshop, jossa tutustuttiin tarkemmin ilmastonmuutokseen. Hiilineutraalius saavutetaan selvittämällä toiminnasta aiheutuvat kasvihuonekaasupäästöt. Tämän jälkeen toimintaa muutetaan vähäpäästöisemmäksi ja lopuksi jäljelle jäävät kasvihuonekaasupäästöt kompensoidaan. Vaikka Sinfonia Lahden merkittävimmät kasvihuonekaasupäästölähteet ovat liikenne sekä energiankulutus, päästövähennyksiä tulee tehdä pysyvästi kaikista mahdollisista toiminnoista. Erityisen tärkeää on saada sidosryhmät osallistumaan sinfoniaorkesterin asettamiin vähennystavoitteisiin. Kompensoinnilla on merkittävä rooli hiilineutraaliuden saavuttamisessa. Tällä hetkellä maailman sinfoniaorkesterit eivät aktiivisesti pyri hiilineutraaliin toimintaan.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Pumping, fan and compressor systems consume most of the motor electricity power in both the industrial and services sectors. A variable speed drive brings relevant improvements in a fluid system leading to energy saving that further on can be translated into Mtons reduction of CO 2 emissions. Standards and regulations are being adopted for fluid handling systems to limit the less efficiency pumps out of the European market on the coming years and a greater potential in energy savings is dictated by the Energy Efficiency Index (EEI) requirements for the whole pumping system and integrated pumps. Electric motors also have an International Efficiency (IE) classification in order to introduce higher efficiency motors into the market. In this thesis, the applicability of mid-size common electric motor types to industrial pumping system took place comparing the motor efficiency characteristics with each other and by analyzing the effect of motor dimensioning on the pumping system and its impact in the energy consumption.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Tässä kandidaatintyössä selvitetään kirjallisuustutkimuksena sähkön yleissiirtohinnat Suomessa vuonna 2015. Työssä vertaillaan sähkön siirtohintoja erilaisilla kotitalouskuluttajilla ja tutkitaan sähkönsiirron hinnoitteluun vaikuttavia tekijöitä. Työssä esitetään myös tulevaisuudessa mahdollisesti käytettäviä siirtotariffeja. Työ tuo esiin sähkön siirtohinnan komponenttien osuudet sähkönsiirron kokonaishinnasta, sekä havainnollistaa visuaalisesti komponenttien maantieteellistä vaihtelua. Siirtomaksujen vaihtelua erilaisilla kulutuksilla havainnollistetaan käyttämällä kolmea esimerkkikuluttajaa, sekä vertailemalla esimerkkikuluttajien siirtomaksuja keskenään. Siirtomaksujen kokonaiskustannusten maantieteellistä vaihtelua havainnollistetaan kuvien avulla. Energiaviraston regulaation vaikutuksia siirtohintaan tarkastellaan verkkoyhtiöiden yli- ja alijäämien avulla. Tulevaisuuden siirtotariffeista huomio kiinnittyy kaistahinnoitteluun. Kaistahinnoittelua tarkastellaan kuluttajan kannalta ja samalla tuodaan esiin kaistahinnoittelun etuja nykyisin käytössä oleviin siirtotariffeihin. Työn perusteella voidaan tehdä johtopäätös, että sähkön kulutuksen kasvaessa siirtomaksu kulutettua energiayksikköä kohden pienenee. Toisin sanoen perusmaksun osuus on merkittävä pienillä kulutusmäärillä ja sen suhteellinen osuus siirtomaksuista pienenee kulutuksen kasvaessa.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Global energy consumption has been increasing yearly and a big portion of it is used in rotating electrical machineries. It is clear that in these machines energy should be used efficiently. In this dissertation the aim is to improve the design process of high-speed electrical machines especially from the mechanical engineering perspective in order to achieve more reliable and efficient machines. The design process of high-speed machines is challenging due to high demands and several interactions between different engineering disciplines such as mechanical, electrical and energy engineering. A multidisciplinary design flow chart for a specific type of high-speed machine in which computer simulation is utilized is proposed. In addition to utilizing simulation parallel with the design process, two simulation studies are presented. The first is used to find the limits of two ball bearing models. The second is used to study the improvement of machine load capacity in a compressor application to exceed the limits of current machinery. The proposed flow chart and simulation studies show clearly that improvements in the high-speed machinery design process can be achieved. Engineers designing in high-speed machines can utilize the flow chart and simulation results as a guideline during the design phase to achieve more reliable and efficient machines that use energy efficiently in required different operation conditions.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This work presents synopsis of efficient strategies used in power managements for achieving the most economical power and energy consumption in multicore systems, FPGA and NoC Platforms. In this work, a practical approach was taken, in an effort to validate the significance of the proposed Adaptive Power Management Algorithm (APMA), proposed for system developed, for this thesis project. This system comprise arithmetic and logic unit, up and down counters, adder, state machine and multiplexer. The essence of carrying this project firstly, is to develop a system that will be used for this power management project. Secondly, to perform area and power synopsis of the system on these various scalable technology platforms, UMC 90nm nanotechnology 1.2v, UMC 90nm nanotechnology 1.32v and UMC 0.18 μmNanotechnology 1.80v, in order to examine the difference in area and power consumption of the system on the platforms. Thirdly, to explore various strategies that can be used to reducing system’s power consumption and to propose an adaptive power management algorithm that can be used to reduce the power consumption of the system. The strategies introduced in this work comprise Dynamic Voltage Frequency Scaling (DVFS) and task parallelism. After the system development, it was run on FPGA board, basically NoC Platforms and on these various technology platforms UMC 90nm nanotechnology1.2v, UMC 90nm nanotechnology 1.32v and UMC180 nm nanotechnology 1.80v, the system synthesis was successfully accomplished, the simulated result analysis shows that the system meets all functional requirements, the power consumption and the area utilization were recorded and analyzed in chapter 7 of this work. This work extensively reviewed various strategies for managing power consumption which were quantitative research works by many researchers and companies, it's a mixture of study analysis and experimented lab works, it condensed and presents the whole basic concepts of power management strategy from quality technical papers.