• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • Tagged with
  • 5
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Green Room: A Giant Leap in Development of Green Datacenters

El Azzi, Charles, Izadi, Roozbeh January 2012 (has links)
In a world that is slipping towards a global energy crisis as a result of a heavy dependence on depleting fossil-based fuels, investment in projects that promote energy efficiency will have a strong return on investment not only economically but also socially & environmentally. Firms will directly save significant amounts of money on their energy bills and besides, contribute to slowing down the environmental degradation & global warming by diminishing their carbon footprint. In the global contest to achieve high levels of energy efficiency, IT sector is no exception and telecommunication companies have developed new approaches on how to develop more efficient data centers and cooling systems in the past decades. This paper describes an ambitious project carried out by TeliaSonera to develop a highly-energy-efficient cooling approach for data centers called "Green Room". It is important to realize that Green Room approach is not specifically limited to data centers. It is designed to support any sort of “technical site” in need of an efficient cooling system. As a result, the word “datacenter” repeatedly used in this paper is expandable to a huger category of technical sites. As the hypothesis, Green Room was expected to generate appropriate temperature level accompanied with effectual steady air flow inside the room while using considerably lower amount of electricity compared with other cooling methods in the market. To begin with, an introduction is given to familiarize the readers with the concept of "data center" and immediately preceded a concise discussion in Chapter 2 providing convincing reasons to promote energy-efficient projects like Green Room from economic, social and environmental points of view. The chapter is complemented by a comprehensive part attached to this paper as Appendix I. In Chapter 3, the different cooling approaches currently available for datacenters is looked into. Chapter 4 describes how it is possible to assess the efficiency of a data center cooling system by introducing critical values such as PUE (power usage effectiveness) and COP (Coefficient of performance). Understandably, it is of great significance to determine how accurate the measurements carried out in this project are. Chapter 5 provides useful information on measurements and describes uncertainty estimation of the obtained results. Chapter 6 explains the test methodology and continues by touching on the components of Green Room and their technical specifications. Subsequently, it compares the Green Room approach to other cooling systems and identifies five major differences making the Green Room a distinctive cooling method. Chapter 7 explains the measurement requirements from the point of view of sensors, discusses the calibration process and finally represents the uncertainty calculations and their results. Chapter 8 broadly describes the five different categories of 25 independent tests carried out within a period of almost two weeks. It provides the readers with all the necessary details for each test and includes thorough description of conditions, numerical results, calculations, tables, charts, graphs, pictures and some thermal images. Ultimately, the last two chapters summarize the results of this project and assess its degree of success based on the hypothesis of this paper. Consequently, a number of questions have been raised and relevant suggestions made to modify this approach and improve the results. Surprisingly, the values obtained for efficiency of this cooling system are as expected. However, some part of calculations to achieve the total power load of the whole cooling production system is based on estimations acquired from software simulations. Overall, this is considered as a successful project fulfilling the primary expectations of the founders.
2

Improving Phosphorus Use Efficiency Through Organically Bonded Phosphorus

Hill, Micheal W 07 December 2012 (has links) (PDF)
Current maximum efficiency of phosphorus (P) fertilizers that is utilized by plants in the same year of application ranges from near zero to thirty percent. Despite low utilization of P in crop production, yields are often limited by P deficiencies. Innovative technology is requisite to achieve greater efficiency as fertilizer demands are increasing, while phosphorus mineral resources are rapidly being depleted. A growing environmental concern for nutrient pollution of surface waters also carries significant weight. A novel new product, Carbond® P, is promising technology to increase P use efficiency. Research is needed to understand its capabilities and the functioning mechanisms imbedded within its technology. Several research studies were conducted to evaluate Carbond® P (CBP) against traditional fertilizers ammonium polyphosphate (APP) and monoammonium phosphate (MAP). A soil column leaching study was conducted to determine P mobility through three soils, at two rates (20 and 30 kg P ha-1) in either a banded or mixed soil application. Mobility of P was evaluated at 24, 48, 110 and 365 d after fertilization. CBP showed significantly greater total P leachate values across all soil types and application rates averaged across all readings taken until 365 daf for both application types. In the banded applications, CBP generally produced significantly greater solubility than MAP or APP up until 110 daf. For applications mixed with soil, CBP and MAP had greater solubility than APP at 24 days after application, but by the later evaluation dates (48 and 110 daf) the CBP was significantly higher than both MAP and APP. No statistical significance was found in the leachate P 365 daf in either the banded or mixed applications. One glasshouse study on maize (Zea mays L.) grown in three soils were conducted at 0, 5, 10, 20, 40, 80, and 160 kg P ha-1 comparing CBP and APP fertilizer impacts on early season growth. CBP produced significantly more biomass in two soils when averaged across rates (and at the 20 kg P ha-1 rate in a third soil), increased petiole P in one soil and thicker stems in another. Two field trials showed similar physiological advantages with CBP over APP at later growth stages. CBP maize responded with significantly more biomass and P uptake at the V12-V18 growth stages in one field, as well as plant height in another. At the R2-R3 growth stages, CBP also produced thicker stalks in both fields than APP. These growth enhancements were strongest in medium to highly calcareous soil (6-12 %) low in P (7 mg kg-1). These observations warrant the use of CBP and further investigation to understand its benefits and limitations.
3

The impact of innovative ICT technologies on the power consumption and CO2 emission of HTTP servers

Soler Domínguez, Sebastian January 2022 (has links)
The ICT technologies and their adoption from the population are growing fast, and the energy that this industry requires has followed the same trend, even considering all the improvements in efficiency during the last decades. This is because the increment in data centers and information outpaces all the efficiencies that have been adopted over the years. The HTTP servers have been optimizing data usage performance over the years, however, data centers still consume more and more energy due to the high demand they have. The objective of this study is to develop a tool that compares cache and non-cache servers' energy, hence CO2 emissions performances, using a simple and an advanced model. The simple model is based on a compilation of extensive data analysis including more detailed information and inputs, and the advanced model considers an energy consumption comparison between cache and non-cache technology. A database of CO2 emissions per MWh of 49 countries is created that forecasts this rate until 2030. The results show that cache servers are between 20% and 5% more efficient than non-cache in terms of energy consumption for files under 5MB. However, the efficiency level varies depending on the file size that is transferred. Therefore, improved ICT technology has the potential to reduce thousands of tons of CO2 per year if more websites adopt it. For example, an average news website with 300k visits per day could reduce around 150 tonCO2/year. IKT-teknikerna och deras antagande från befolkningen växer snabbt, och den energi som denna industri kräver har följt samma trend, även med tanke på alla effektivitetsförbättringar under de senaste decennierna. Detta beror på att ökningen av datacenter och information överträffar alla effektivitetsvinster som har antagits under åren. HTTP-servrarna har optimerat dataanvändningsprestanda under åren, men datacenter förbrukar fortfarande mer och mer energi på grund av den höga efterfrågan de har. Syftet med denna studie är att utveckla ett verktyg som jämför cache- och icke-cache-servrars energi, därav CO2-utsläppsprestanda, med hjälp av en enkel och en avancerad modell. Den enkla modellen är baserad på en sammanställning av omfattande dataanalyser inklusive mer detaljerad information och indata, och den avancerade modellen tar hänsyn till en energiförbrukningsjämförelse mellan cache- och icke-cache-teknik. En databas med CO2-utsläpp per MWh för 49 länder skapas som prognostiserar denna takt fram till 2030. Resultaten visar att cacheservrar är mellan 20% och 5% effektivare än icke-cache vad gäller energiförbrukning för filer under 5MB. Effektivitetsnivån varierar dock beroende på filstorleken som överförs. Därför har förbättrad IKT-teknik potential att minska tusentals ton CO2 per år om fler webbplatser använder den. Till exempel kan en genomsnittlig nyhetswebbplats med 300 000 besök per dag minska cirka 150 ton CO2/år.
4

Data center cooling solutions : A techno-economical case study of a data center in Sweden

Sjökvist, Joel, Magnusson, Fredrik January 2022 (has links)
Given the coinciding growth-trend in the production of consumer electronics and generation of data, the increase in server halls and data centers, as a means for hosting storage capacity for the generated data, has been prominent over the last decades. The establishment of data centers in already existing infrastructure can entail major changes in terms of energy system design. The activity of data processing and storage is power intensive and as the centers demonstrate substantial heat generation, one of the most important fractions of the energy use comes from the need to provide cooling. The study is a techno-economic analysis purposed for determining the feasibility of different cooling systems for a data center in Sweden. The investigated building currently hosts an industrial printing press hall in which paper printing has been conducted for the several decades. This press hall is subject to a refurbishment process to eventually be converted into a data center. In order to achieve the objectives, a data center building model is developed, designated for the estimation of the internal heat generation and demand for cooling. The design and energy requirements of a number of cooling solutions are then investigated and evaluated using a number of performance metrics: Power Usage Effectiveness (PUE), Capital Expenditure (CapEx), Operational Expenditure (OpEx) and Life Cycle Cost (LCC). More specifically the systems incorporate technologies for utilizing air-based free cooling, ground-source free cooling through borehole ground source heat exchangers (GHEs), mechanical cooling through compressor-driven machines as well as District Cooling (DC). The results of the study show that free cooling is a viable solution for covering the vast majority of the yearly cooling requirements, during sufficiently low outdoor temperatures. Free cooling, provided through borehole GHE’s, is feasible as a partial solution from a technical point of view, to provide cooling capacity during warmer periods. However, it can not alone act to provide a major part of the relatively high and constant cooling capacity requirements throughout the year. All of the investigated scenarios display a similar energy performance in terms of total PUE, at values well below the national average of 1.37. It is also seen, that the scenario that displays the lowest LCC includes a combination of free cooling and compressor-driven cooling. This holds for the studied sensitivity cases. It is found that a combined system incorporating borehole GHE’s and compressor cooling machines perform the best in terms of a low PUE. However, the relative difference in energy performance turns out to be lesser than the relative difference in LCC, when substituting the borehole GHE’s for additional cooling machine capacity. / I takt med digitaliseringen och en ökad global användningen- och produktionen av hemelektronik, vilket föranlett en ökad generering av data, har antalet datahallar blivit allt fler de senaste decennierna. Datahallens syfte är att hantera och bereda lagringskapacitet för den data som genereras vilket involverar en rad energikrävande processer. Upprättandet av datahallar i redan befintlig infrastruktur kan medföra förändringar när det kommer till utformningen av byggnadens energisystem. Att bedriva datalagring och informationsbehandling kräver påtagliga mängder elektricitet vilket medför stor intern värmealstring och därtill behov av aktiv kylning.  Denna studie, som valt att benämnas som en tekno-ekonomisk fallstudie, undersöker lämpligheten i implementeringen av olika kylsystem för ett byggnadskomplex i Stockholm. I byggnadens lokaler återfinns idag en industrihall där det sedan flera decennier bedrivits tryckeriverksamhet. Industrihallen är föremål för en konverteringsprocess för att på sikt bli en datahall. Studien är centrerad kring denna konverteringsprocess. För att utvärdera kylbehoven för den framtida datahallen har en modell utvecklats som uppskattar interna värmelaster samt reglerar inomhusklimatet efter rådande krav på inomhuskomfort. Därefter studeras utformning och energibehov för flera olika typer av kylsystemlösningar där en utvärdering av dessa system görs utifrån indikatorerna Power Usage Effectiveness (PUE), Capital Expenditure (CapEx),Operational Expenditure (OpEx) and Life Cycle Cost (LCC). Mer konkret undersöks kombinerade kylsystem som utnyttjar luftburen frikyla, geotermisk frikyla via bergvärmeväxlare (GHEs), mekanisk kyla via kompressordriven kylmaskin samt regional fjärrkyla. Resultaten från studien visar att frikyla från kylmedelskylare är en lämplig lösning för att täcka majoriteten av datahallens kylbehov över ett år, med undantag för årets varmare perioder. Geotermisk frikyla via borrhål är möjlig som partiell lösning ur ett tekniskt perspektiv, men kan inte enskild leverera en majoritet av effekt- eller energibehovet av kyla. Resultatet visar också att alla undersökta scenarier uppvisar en liknande energiprestanda i termer av total PUE, med värden som underskrider det nationella genomsnittet 1,37. Lägst LCC påvisades för ett system som kombinerar luftburen frikyla via kylmedleskylare och mekanisk kyla via kompressordrivna kylmaskiner. Denna låga LCC är signifikant vilket påvisas i utförd känslighetsanalys. Slutligen konstateras att ett system innefattande luftburen och geotermisk frikyla i kombination med kompressordrivna kylmaskiner resulterar i lägst PUE bland de undersökta scenarierna. Den relativa skillnaden i energiprestanda visar sig vara mindre än den relativa skillnaden i LCC, när geotermisk frikyla ersätts med ytterligare kapacitet från kylmaskiner.
5

Environmental Performance of the Försäkringskassan IT Infrastructure : A Green-IT case study for the Swedish Social Insurance Agency

Honée, Caspar January 2013 (has links)
This Green IT case study commissioned by Försäkringskassan (FK), the Swedish National Social Insurance Agency, quantifies the environmental performance of the IT infrastructure (IT-IS) in use during 2010 in a lifecycle perspective. Adopting a system view in Green IT analysis can mitigate risks of problem shifts. IT-IS concerns the equipment that enables office automation and external web application services. The size of the FK IT-IS is in the order of 300 branch offices with 14000 pc’s, 2100 printers and a 1 MW data centre hosting 1200 servers, 5 Petabyte of central data storage and serving about 80 key business applications. The carbon footprint of the FK IT-IS in 2010 accounts to 6.5 kiloton CO2-equivalents. The total environmental impact is calculated across 18 themes and expressed as a single indicator eco score amounting to 822.000 ReCiPe points. The contribution of capital goods is large with 44% of the carbon footprint and 47% of the eco score linked to emissions embedded in material equipment. The environmental effects from distributed IT deployed at local office sites, dominate at two thirds of the total FK IT-IS impacts. Important drivers in the local office sites category are the relatively short economic life span of pc equipment and the significant volume of paper consumed in printing activities. Within the data centre category, operational processes dominate the environmental impacts and are linked to intensive power use. In comparison to industry benchmark scores, the data centre infrastructure energy efficiency (DCiE) is relatively low at 57%, or 59% when credited for waste heat utilisation. Airflow containment measures in computer rooms are identified for efficiency improvement. Enhanced airflow controls also act as a prerequisite to better leverage opportunities for free cooling present at the location in northern Europe.  With regards to the data centre hosted IT, environmental impacts linked to storage services dominate and remarkably exceed those of servers. / Denna fallstudie inom Grön IT på uppdrag av Försäkringskassan (FK) kvantifierar IT-infrastrukturens (IT-IS) miljöprestanda i ett livscykelperspektiv under 2010. Att införa ett systemperspektiv inom Grön IT analys kan lindra riskerna av problemväxling. IT-IS avser utrustning som möjliggör kontorsautomatisering och externa webbapplikationer. FK IT-IS omfattar 300 kontor med 14,000 datorer, 2,100 skrivare och ett 1 MW datacenter med 1,200 servrar, 5 Petabyte central datalagring och 80 huvudsakliga applikationer. Koldioxidavtrycket av det totala FK IT-IS utgör 6,5 kiloton CO2-ekvivalenter för 2010 . Den totala miljöpåverkan är beräknad över 18 miljöteman och anger som en enda indikator ekobetyget på 822,000 ReCiPe poäng . Kapitalvaror bidrar stort, med hela 44% av koldioxidutsläppen och 47% av ekobetyget kan härledas till inbäddade utsläpp i material utrustning. Miljöeffekterna av de lokala kontorens IT dominerar med två tredjedelar av den totala FK IT-IS miljöpåverkan. Viktiga faktorer i kategorin lokala kontor är kapitalvarornas relativt korta ekonomiska livslängd samt de betydande volymer av skrivarpapper som används.   Inom datacenterkategorin domineras miljöpåverkan av de operativa processerna som är kopplade till intensiv el förbrukning. I jämförelse med branschstandarden är energieffektiviteten av datacentrets infrastruktur (DCiE) relativt låg, med 57%, alternativt 59% när användandet av spillvärme inräknas. Luftflöde inneslutningsåtgärder i datorsalar identifieras för effektivisering. Förbättrad luftflödesinneslutning i datahallarna är identifierad som en energieffektivisering. Den förbättrade luftflödeskontrollen är också ett krav för att bättre kunna utnyttja möjligheterna för fri kyla som finns i Norra Europa.  Med avseende på datacentrets IT, domineras miljökonsekvenserna kopplade till lagringstjänster och överstiger anmärkningsvärt effekterna från servrarna. / Miljöutredning Grön IT på Försäkringskassan - examensarbeten

Page generated in 0.0275 seconds