• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3205
  • 1727
  • 715
  • 651
  • 389
  • 363
  • 156
  • 140
  • 125
  • 123
  • 117
  • 108
  • 83
  • 56
  • 44
  • Tagged with
  • 9129
  • 2185
  • 1289
  • 1025
  • 843
  • 816
  • 569
  • 489
  • 477
  • 476
  • 464
  • 424
  • 399
  • 387
  • 373
  • 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.
241

The assessment of Replacement Heifer Production Efficiencies through Residual Feed Intake and Key Hormone Profiles

Smith, Brock Andrew 04 January 2013 (has links)
Biological factors regulating feed efficiency were investigated in replacement beef heifers to establish factors that differ between efficient and less efficient animals. Feed efficiency, measured as residual feed intake (RFI) adjusted for body ultrasound measurements, was determined in forty-seven cross-bred heifers. Reproductive differences between efficient (low RFI) and less efficient (high RFI) heifers were examined. Low RFI heifers had an earlier age at both sexual maturity (P=0.08) and conception (P=0.08), and delivered heavier calves (P=0.006). The potential of fecal progesterone metabolites (FP4M) as an indicator of sexual maturity was examined. Measurements of FP4M present a promising non-invasive alternative technique for determining the onset of sexual maturity. A subset of 36 heifers was used to determine if plasma triiodothyronine (T3) concentrations could be used to predict feed efficiency. Triiodothyronine concentrations a correlation of 0.58 (P=0.001) to those from a quadratic prediction model of RFI in heifers sampled as yearlings. / Research into reproductive characteristics associated with residual feed intake, and to determine the effectiveness of the thyroid hormones as a screening tool for feed efficient animals. / OMAFRA (Ontario Ministry of Agriculture, Food, and Rural Affairs) through the Farm Innovation Program, Agriculture Canada through the Growing Forward Project, the Canadian Cattlemen’s Association through the Beef Cattle Research Council, and the Ontario Cattlemen’s Association.
242

Mobile clouds: a flexible resource sharing platform towards energy, spectrum and cost efficient 5G networks

Bagheri, H. (Hamidreza) 28 November 2017 (has links)
Abstract Recent advances in wireless communications coupled with the widespread of bandwidthhungry and high-power consuming wireless services as well as the rapid penetration of multimedia-enabled smart handheld devices generate a drastic growth in mobile traffic volume. With these trends, the goals of 5G and beyond wireless communications include energy efficiency, low latency, and low service cost from the user’ perspective as well as spectrum efficiency, revenue increasing, and lower capital and operational cost from the network operators’ point of view. This thesis studies the potential of mobile clouds for improving energy, spectral, and cost efficiency towards the primary goals of 5G networks. Mobile clouds define a promising 5G integrated technology which combines the conventional cellular and shortrange networks into a novel and powerful communication architecture. Mobile clouds can be seen as a flexible and efficient platform for cooperative content delivery, cooperation, resource sharing, and social networks. Research work in this thesis is conducted in two main areas, namely fundamental and applied research on mobile clouds. Fundamental research focuses on cloud formation strategies and cloud maintenance mechanisms. In the applied area, the potential of mobile clouds for content distribution is investigated in both licensed and unlicensed bands. For content distribution using unlicensed band, several cooperative strategies are designed and their efficiency is compared to traditional multicast strategy in terms of energy efficiency, content distribution latency, and users’ quality of experience (QoE). In content distribution over licensed band, spectrum sharing and resource allocation algorithms are considered for multi pair and full-duplex device-to-device (D2D) communications, aiming at improving spectral efficiency and network performance as well as quality of service (QoS) provisioning. In addition, a business model is designed to consider how mobile clouds can reduce the cost of users and operators while improving revenue of operators and increasing users’ satisfaction. The results of this thesis show that mobile clouds technology creates a flexible and efficient platform which can efficiently enhance spectral efficiency, significantly improve energy efficiency and network performance while guaranteeing cost efficiency for users and network operators simultaneously. / Tiivistelmä Langattomassa viestinnässä on viime aikoina saavutettu useita edistysaskeleita samalla kun suurta kaistanleveyttä edellyttävien ja paljon tehoa kuluttavien langattomien palveluiden käyttö on yleistynyt ja multimediatoiminnoilla varustetut älylaitteet ovat vallanneet nopeasti markkinoita. Tämän seurauksena mobiililiikenne on lisääntynyt huomattavasti. Näiden suuntausten valossa langattoman 5G-viestinnän ja sitä seuraavien sukupolvien langattoman viestinnän kehitystavoitteita ovat muun muassa seuraavat: käyttäjän näkökulmasta energiatehokkuus, mahdollisimman lyhyet viiveajat ja palvelun käytöstä aiheutuvien kustannusten edullisuus sekä verkko-operaattorin näkökulmasta spektritehokkuus, tulojen kasvattaminen ja aiempaa matalammat pääoma- ja käyttökustannukset. Tässä väitöskirjassa tarkastellaan millaisia mahdollisuuksia mobiilipilvet tarjoavat energia-, spektri- ja kustannustehokkuuden parantamiseen ja siten 5G-verkkojen päätavoitteiden saavuttamiseen. Mobiilipilvi on lupaava osa 5G-teknologiaa, jossa perinteiset solukkoverkot ja lyhyen kantaman verkot yhdistyvät aivan uudenlaiseen ja tehokkaaseen tietoliikennearkkitehtuuriin. Mobiilipilvet voidaan nähdä joustavana ja tehokkaana alustana sisällön yhteisjakelulle, yhteistyölle, resurssien jakamiselle ja toiminnalle sosiaalisissa verkoissa. Tätä väitöskirjaa varten on tehty tutkimusta sekä mobiilipilviä koskevan perustutkimuksen että soveltavan tutkimuksen parissa. Perustutkimuksessa keskitytään tarkastelemaan pilvien muodostamisessa käytettäviä strategioita ja pilvien ylläpidossa käytettäviä mekanismeja. Soveltavan tutkimuksen alueella mobiilipilvien tarjoamia sisällön jakelun mahdollisuuksia tarkastellaan sekä luvanvaraisilla että vapaasti käytettävillä kaistoilla. Vapaasti käytettävillä kaistoilla toteutettavaa jakelua varten työssä kehitetään useita yhteistoimintastrategioita, joiden tehokkuutta verrataan perinteiseen monilähetysstrategiaan energiatehokkuuden, sisällön jakelun viiveiden ja käyttäjien kokemuksen laadun (Quality of Experience, QoE) osalta. Luvanvaraisilla kaistoilla toteutettavan sisällön jakelun osalta tarkastellaan moniparisessa ja samanaikaisessa molemminsuuntaisessa laitteiden välisessä viestinnässä (D2D-kommunikaatiossa) käytettäviä spektrin jakamisen ja resurssien allokoimisen algoritmeja, jotta spektritehokkuutta ja verkon suorituskykyä sekä palvelun laatua (Quality of Service, QoS) pystyttäisiin parantamaan. Tämän lisäksi työssä kehitellään liiketoimintamallia, jonka avulla voidaan pohtia, miten mobiilipilvillä voidaan vähentää käyttäjien ja operaattorien kustannuksia ja samalla kasvattaa operaattorien tuloja ja parantaa käyttäjien tyytyväisyyttä. Tämän työn tulokset osoittavat, että mobiilipilviteknologia on joustava ja tehokas alusta, jolla voidaan lisätä olennaisesti spektritehokkuutta, parantaa merkittävästi energiatehokkuutta ja verkon suorituskykyä sekä taata kustannustehokkuus sekä käyttäjien että verkko-operaattorien näkökulmasta.
243

The Non-Energy Benefits of Industrial Energy Efficiency : Investments and Measures

Nehler, Therese January 2016 (has links)
Improved industrial energy efficiency is viewed as an important means in the reduction of CO2 emissions and climate change mitigation. Various energy efficiency measures for improving energy efficiency exists, but even evaluated as cost-effective, there seems to be a difference between the energy efficiency measures that theoretically could be undertaken and which measures that actually are realised. On the other hand, industrial energy efficiency measures might yield extra effects, denoted as non-energy benefits, beyond the actual energy savings or energy cost savings. Based on interviews and a questionnaire, results showed that the Swedish industrial firms studied had observed various non-energy benefits. However, few of the non-energy benefits observed were translated into monetary values and included in investment calculations. Results indicated that this non-inclusion could be explained by lack on information on how to measure and monetise the benefits, but even if not translated into monetary values, some of the non-energy benefits were sometimes used qualitatively in investment decisions. The utilisation of the benefits seemed to depend on the type and the level of quantifiability among the perceived benefits. This thesis has also explored energy efficiency measures and non-energy benefits for a specific industrial energy-using process – compressed air. A literature review on energy efficiency in relation to compressed air systems revealed a large variation in which measures that could be undertaken to improve energy efficiency. However, few publications applied a comprehensive perspective including the entire compressed air system. Few non-energy benefits of specific energy efficiency measures for compressed air systems were identified, but the study provided insights into how non-energy benefits should be studied. This thesis suggests that energy efficiency and non-energy benefits in compressed air systems should be studied on specific measure level to enable the observation of their effects. However, the studies also addressed the importance of having a systems perspective; the whole system should be regarded to understand the effects of energy efficiency measures and related non-energy benefits.
244

Spectral, Energy and Computation Efficiency in Future 5G Wireless Networks

Sun, Haijian 01 August 2019 (has links)
Wireless technology has revolutionized the way people communicate. From first generation, or 1G, in the 1980s to current, largely deployed 4G in the 2010s, we have witnessed not only a technological leap, but also the reformation of associated applications. It is expected that 5G will become commercially available in 2020. 5G is driven by ever-increasing demands for high mobile traffic, low transmission delay, and massive numbers of connected devices. Today, with the popularity of smart phones, intelligent appliances, autonomous cars, and tablets, communication demands are higher than ever, especially when it comes to low-cost and easy-access solutions. Existing communication architecture cannot fulfill 5G’s needs. For example, 5G requires connection speeds up to 1,000 times faster than current technology can provide. Also, from transmitter side to receiver side, 5G delays should be less than 1ms, while 4G targets a 5ms delay speed. To meet these requirements, 5G will apply several disruptive techniques. We focus on two of them: new radio and new scheme. As for the former, we study the non-orthogonal multiple access (NOMA) and as for the latter, we use mobile edge computing (MEC). Traditional communication systems allow users to communicate alternatively, which clearly avoids inter-user interference, but also caps the connection speed. NOMA, on the other hand, allows multiple users to transmit simultaneously. While NOMA will inevitably cause excessive interference, we prove such interference can be mitigated by an advanced receiver side technique. NOMA has existed on the research frontier since 2013. Since that time, both academics and industry professionals have extensively studied its performance. In this dissertation, our contribution is to incorporate NOMA with several potential schemes, such as relay, IoT, and cognitive radio networks. Furthermore, we reviewed various limitations on NOMA and proposed a more practical model. In the second part, MEC is considered. MEC is a transformation from the previous cloud computing system. In particular, MEC leverages powerful devices nearby and instead of sending information to distant cloud servers, the transmission occurs in closer range, which can effectively reduce communication delay. In this work, we have proposed a new evaluation metric for MEC which can more effectively leverage the trade-off between the amount of computation and the energy consumed thereby. A practical communication system for wearable devices is proposed in the last part, which combines all the techniques discussed above. The challenges for wearable communication are inherent in its diverse needs, as some devices may require low speed but high reliability (factory sensors), while others may need low delay (medical devices). We have addressed these challenges and validated our findings through simulations.
245

Analytical Framework to Study Energy Efficiency Policy Portfolios across Countries/States

Bhattacharjee, Suchismita 17 August 2010 (has links)
Energy conservation and implementation of effective energy efficiency policies have become imperative to curbing the escalating consumption of energy. The imbalance in the supply and demand of a country's energy has increased the importance of implementing energy efficiency policies. Proper replication of strategic energy efficiency policies that are known to be successful in one country, along with development of new approaches, can be helpful in developing the energy policy portfolio of another country. Some OECD (Organization of Economic Cooperation and Development) countries like Denmark, Finland, France, Germany, Italy, the United Kingdom and the United States have benefited from their energy policies during the most recent energy crisis. The motivation of this research is to provide a tool for developing countries, which are still in the stage of formulating their energy efficiency policies, to compare energy efficiency policy portfolios across countries. These countries can improve their energy efficiency policy portfolios based on lessons learned from the developed countries. The research develops a framework to compare energy efficiency policy portfolios across countries / states. Although this framework can be adopted for any type of energy policy, targeting any sector with few modifications, the current focus is on policies that target the residential building sector to reduce energy consumption. The research begins with identification of the functional domains that influence human behavior–people, economy, environment and technology–followed by identification of the factors affecting household energy consumption. It uses the four functional domains as the evaluation framework's four axes. The various factors affecting household energy consumption are positioned in the framework based on association with the functional domains. The energy efficiency policies implemented in a country are positioned in the same framework based on the pattern of diffusion of each type of policy. In addition, a prototype method is developed to identify the factors targeted by each energy efficiency policy implemented in a country. This evaluation method allows for a uniform assessment process of how energy efficiency policies target specific socio-economic factors that are known to affect energy consumption. The proposed framework will facilitate the work of policy makers and other decision makers with a powerful tool for evaluating and comparing their individual policies, or their complete portfolio of energy efficiency policies, to those from other states or countries, and to benefit from the lessons learned. / Ph. D.
246

A comparative analysis of nutrient utilisation and meat quality parameters of boer goats and South African mutton merinos

Sheridan, Rouxlene 12 1900 (has links)
Thesis (MScAgric)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: One of the reasons why meat supply does not meet human demand is that man has concentrated on utilising relatively few animal species as a source of meat. Development of unconventional livestock, such as goats, is advocated as a means of increasing global meat production and consumption. Although South Africa possesses large numbers of domestic ruminants, meat consumption has been limited mainly to sheep and cattle. Goats are used to a lesser extent. This is partly attributed to a general belief that goat meat is inferior to mutton and beef. Numerous contradictions regarding comparative goat and sheep growth, carcass characteristics and meat composition exist in literature. Concepts involved with most of the contradictions includes average daHy gain (ADG), dressing percentage, carcass weight distribution and organoleptic characteristics, especially tenderness, juiciness and flavour, particularly as pertaining to animals reared/grown under intensive/feedlot conditions. Therefore this project was undertaken to obtain more information on the growth, carcass and organoleptic characteristics, as well as meat chemical compositions of Boer goat (BG) kids in comparison with South African Mutton merino (MM) lambs, reared under feedlot conditions. Thirty-two BG kids and 32 MM lambs were used for this investigation. All the animals were castrated and weaned before entering the feedlot. Two pelleted diets (fed to 16 animals/species) with either a low (LE; 8.9 MJ/kg OM) or a high (HE, 10.9 MJ/kg OM) metabolisabie energy level were fed individually, ad lib for either 28 or 56 days. Feed and water intake, ADG and feed conversion efficiencies (FCE) were monitored. During the last week of the feeding trial, 12 BG kids and 12 MM lambs were used to evaluate the digestibility of the two diets. After either 28 or 56 days, the animals were slaughtered and the carcasses dissected into South African commercial cuts. The m. semimembranosus and 8-9-10-rib cut of each carcass was dissected for determination of chemical composition, drip loss, cooking loss, shear force values and colour measurement. The m. gracilis was dissected from the hind leg of the carcass and used for sensory evaluation. MM's had significantly higher AOG's than BG's (e.g. MMHE56: 0.281; BGHE56: 0.162 kg/day). Within a diet there was no difference (P>0.05) in FCE between BG's and MM's and only the MM's FCE differed between the LE and HE diet (e.g. BGLE28: 7.65; BGHE28: 6.37; MMLE28: 8.73; MMHE28: 5.56 kg feed/kg weight gain). BGLE digested dry matter (OM), crude protein (CP) and energy more efficiently and had a higher energy retention than MMLE. The two diets had the same ME-value for the goats, which confirms that goats perform equally well on a lower quality feed as their contemporaries on a higher quality feed. Neither species, nor diet affected nitrogen retention. The BG had a 49 % lower (P<0.01) water intake per kg weight gain than the MM on both the high and low energy diets. Both species had a lower (P<0.01) water intake on the high than on the low energy diet. Furthermore, the BG had a daily water intake of only 171 ml/kgo.75 compared to the 302 ml/kgo.75 of the MM. The weight of the liver, empty stomach, head and feet (as a percentage of empty body weight) were higher in goats than in sheep. The MM's had significantly heavier skins, probably due to wool growth. Both kidney fat and gastro-intestinal tract (GIT) fat increased with age. The animals slaughtered after 56 days in the feedlot had significantly longer and deeper carcasses than their contemporaries slaughtered after 28 days. Within a diet and slaughter age, the MM had significantly broader and deeper carcasses than the BG's. BG's had significantly less weight per unit carcass length, and thus more slender carcasses than MM's. Diet had no significant influence on the carcass weight distribution of the goats. However, MM's had heavier carcasses (LE: 19.87 vs. 15.28 kg; HE: 24.01 vs. 17.05 kg) and proportionally heavier ribs and buttocks than BG's. Neither diet nor slaughter age influenced the proximate analysis of the m. semimembranosus, but MM's had significantly lower moisture values than BG's. In the 8-9-10-rib cuts BG's had significantly more moisture and protein and lower fat and energy values than MM's. OM, fat and energy values increased with an increase in slaughter age in both species. BG's had significantly higher concentrations of 11 of the 18 measured essential amino acids in their 8-9- 10-rib cuts than the MM's. Gaat carcasses had higher Ca, K, Mg, Na and P-Ievels than sheep carcasses, regardless of the diet fed. There was a tendency for goat's m. semimembranosus to have a lower Fe-content than that of sheep. BG carcasses had a lower carcass cholesterol content than that of lamb (66.77 vs. 99.28 mg/100g, respectively). Palmitic (C16:0), stearic (C18:0) and oleic (C18:1 n9) acid comprised the greatest proportions of fatty acids in both the m. semimembranosus and 8-9-10-rib cut for both species. On a LE-diet there was no significant difference between the saturated fatty acid (SFA) to unsaturated fatty acid (UFA) ratio of goat meat and lamb. However, on the HEdiet, lamb had a significantly higher SFA:UFA ratio than chevon (m. semimembranosus: 0.842 vs. 0.689; 8-9-10-rib cut: 1.407 vs. 0.892). Organoleptically, a difference was noted between chevon and lamb. Each has a specific species flavour, which was not influenced by energy level of the diet. BG meat was perceived to be stringier than that of the MM, but there was no significant difference in Warner-Bratzler shear force values. Tenderness declined with age in both species and there was also a tendency for goat meat to be less juicy than lamb. Chevon had a more pronounced aftertaste than lamb. No objective differences could be distinguished between the colour of the cooked chevon and lamb. There was a tendency for fresh lamb to have a higher a*-value (redness) than chevon. Although diet did not influence drip loss, drip loss increased with an increase in slaughter age. Only after 56 days did the MM's m. semimembranosus have a significantly higher drip loss than the BG's (LE: 4.84 vs. 3.43%; HE: 4.72 vs. 3.32%). In the m. semimembranosus of both species, cooking loss increased with an increase in slaughter age. Since diet did not influence the growth, carcass weight distribution, water holding capacity, colour, shear force values or organoleptic qualities of chevon, BG's may be finished on a diet with a lower ME-value than that usually formulated for sheep, without a reduction in performance. This may render a direct economic advantage for BG feedlot finishing. Meat from young feedlot goats is not inferior to that of lamb and it has a higher protein percentage and lower fat percentage. Therefore, it can be considered as a healthy food commodity, especially among low-income groups or people wishing to consume a low calorie diet. / AFRIKAANSE OPSOMMING: 'n Vergelykende analise van nutriëntverbruik en vleiskwaliteisparameters van Boerbokke en Suid-Afrikaanse Vleismerino's: Een van die hoofredes waarom die vraag na vleis die aanbod oorskrei, is die feit dat die mens tot op hede net op 'n paar dierspesies as bron van vleis gekonsentreer het. Benutting van niekonvensionele spesies, soos bokke, kan aanbeveel word ten einde die globale vleisproduksie en -verbruik te verhoog. Ten spyte van die feit dat Suid-Afrika oor baie gedomestikeerde herkouerspesies beskik, is vleisverbruik in die verlede tot hoofsaaklik skape en beeste beperk. Bokke is tot 'n mindere mate gebruik. Dit kan gedeeltelik toegeskryf word aan die algemene siening dat bokvleis ondergeskik aan skaap- en beesvleis is. Verskeie teenstrydighede ten opsigte van vergelykings tussen bokke en skape se groei, karkaseienskappe en vleissamestelling bestaan in die literatuur. Teenstrydige resultate ten bpsigte van gemiddelde daaglikse toename (GOT), uitslagpersentasie, karkasgewigverspreiding en organoleptiese eienskappe (veral taaiheid, sappigheid en geur) van diere afgerond onder intensiewe/voerkraal-toestande, kom veral voor. Hierdie projek is vervolgens uitgevoer ten einde meer inligting ten opsigte van die groei, karkas- en organoleptiese eienskappe, sowel as die chemiese samestelling van die vleis van Boerbok (BB) lammers in vergelyking met Suid-Afrikaanse Vleismerino (VM) lammers, onder voerkraal-toestande grootgemaak, te verkry. Twee-en-dertig BB lammers en 32 VM lammers is vir hierdie studie gebruik. AI die diere is gekastreer en gespeen voor hulle in die voerkraal geplaas is. Twee verpilde diëte (gevoer aan 16 diere/spesie) met óf 'n lae (LE, 8.9 MJ/kg DM) óf 'n hoë (HE, 10.9 MJ/kg DM) metaboliseerbare energievlak is individueel, ad lib, vir óf 28 óf 56 dae aan die diere gevoer. Voer- en waterinname, GOT en voeromsettingsdoeltreffendheid (VOD) is gemonitor. Gedurende die laaste week van die voedingsproef is 12 BB'e en 12 VM's gebruik ten einde die verteerbaarheid van die twee diëte te bepaal. Na 28 of 56 dae is die diere geslag en die karkasse in Suid-Afrikaanse kommersiële snitte verdeel. Die m. semimembranosus en 8-9-10-rib snit van elke karkas is verwyder vir bepaling van chemiese samestelling, drupverlies, kookverlies, skeurwaardes en kleurbepaling. Die m. gracilis is uit die agterbeen uitgehaal en vir sensoriese evaluering gebruik. VM's het betekenisvolle hoër GOT's as BB'e (bv. VMHE56: 0.281; BBHE56: 0.162 kg/dag) gehad. Binne 'n dieet was daar geen verskille (P>0.05) in VOD tussen BB'e en VM's nie en net die VM's se VOD het tussen die LE- en HE-dieet verskil (bv. BBLE28: 7.65; BBHE28: 6.37; VMLE28: 8.73; VMHE28: 5.56 kg voer/kg gewigstoename). BBLE het die droë materiaal (DM), ruproteïen (RP) en energie meer effektief verteer en het 'n hoër energieretensie as VMLE gehad. Die twee diëte het dieselfde ME-waarde vir die bokke gehad, wat bevestig dat bokke net so goed op 'n laer kwaliteit voer presteer as op 'n dieet van 'n hoër kwaliteit. Stikstofretensie is nie deur spesie of dieet beïnvloed nie. Die BB het 'n 49% laer (P<0.01) waterinname per kg massatoename op beide die HE- en LE-dieet gehad. Beide spesies het 'n laer (P<0.01) waterinname op die hoë as die lae energie dieet gehad. Verder het die BB ook 'n daaglikse waterinname van slegs 171 ml/kg075 gehad in vergelyking met die 302 ml/kgO.75van die VM. Die gewig van die lewer, leë pens, kop en pote (as persentasie van leë liggaamsgewig) was hoër vir bokke as vir skape. Die VM's se velle was betekenisvol swaarder, waarskynlik as gevolg van wolgroei. Beide niervet en kanaalvet het toegeneem met 'n toename in slagouderdom. Die diere wat na 56 dae in die voerkraal geslag is, het betekensivol langer en dieper karkasse gehad as dié na 28 dae. Binne 'n dieet en slagouderdom, het die skape breër en dieper (P<0.05) karkasse as die bokke gehad. BB'e het betekenisvol minder gewig per eenheid karkaslengte en dus maerder karkasse as VM's gehad. Dieet-energievlak het geen betekenisvolle effek op die verspreiding van karkasgewig by bokke gehad nie. VM's het egter swaarder karkasse (LE: 19.87 vs. 15.28 kg; HE: 24.01 vs. 17.05 kg) en proporsioneel swaarder ribbes en boude as BB'e gehad. Dieet of slagouderdom het nie 'n betekenisvolle effek op die chemiese samestelling (vog, vet, proteïen en as) van die m. semimembransous gehad nie, maar VM's het laer (P<0.05) vogwaardes as BB'e gehad. In die 8-9-10-rib snit het BB'e betekenisvolle hoër vog en proteïen, maar laer vet- en energiewaardes as VM's gehad. In beide spesies het DM, vet en energiewaardes toegeneem met 'n toename in slagouderdom. BG'e het 'n betekenisvolle hoër konsentrasie in 11 van die 18 gemete essensiële aminosure in hul 8-9-10-rib snitte gehad in vergelyking met VM's. Bokkarkasse het ook hoër Ca, K, Mg, N en P-vlakke as skaapkarkasse gehad, ongeag die dieet. Daar was 'n neiging vir die bok m. semimembranosus om 'n laer Fe-inhoud as dié van die skaap te hê. BB-karkasse het 'n laer cholesterol-inhoud as skaapkarkasse (66.77 vs. 99.28 mg/100g, onderskeidelik) gehad. Palmitiensuur (C16:0), steariensuur (C18:0) en oleïensuur (C18:1n9) het die grootste proporsies van die vetsure in beide die m. semimembranosus en 8-9-10-rib snit van beide spesies uitgemaak. Op 'n LE-dieet was daar geen verskil tussen die versadigde (SFA) tot onversadigde (UFA) vetsuur-verhouding van bok- en skaapvleis nie. Op 'n HE-dieet het skaapvleis egter 'n betekenisvol hoër SFA:UFA-verhouding as bokvleis gehad (m. semimembranosus: 0.842 vs. 0.689; 8-9-10-rib snit: 1.40 vs. 0.892, onderskeidelik). Organolepties is 'n verskil tussen bok- en skaapvleis gevind. Elkeen het 'n spesifieke spesiegeur, wat onafhanklik van die dieet was. Bokvleis is waargeneem as meer veselrig as skaapvleis, maar daar was geen verskil in Warner-Bratzler skeurwaardes nie. In beide spesies het sagtheid afgeneem met 'n toename in ouderdom en daar was 'n neiging vir bokvleis om minder sappig as lamsvleis te wees. Bokvleis het ook 'n meer pertinente nasmaak as lam gehad. Geen objektiewe verskil kon tussen die kleur van gekookte skaapen bokvleis onderskei word nie. Daar was egter 'n tendens vir vars lamsvleis om 'n hoër a*- waarde (rooiheid) as bokvleis te hê. Alhoewel dieet nie 'n invloed op drupverlies gehad het nie, het drupverlies toegeneem met 'n toename in slagouderdom. Slegs na 56 dae het die VM se m. semimembranosus 'n hoër (P>0.05) drupverlies as dié van die BB getoon (LE: 4.84 vs. 3.43%; HE: 4.72 vs. 3.32%, onderskeidelik). In die m. semimembranosus van beide spesies het kookverlies toegeneem met 'n toename in slagouderdom. Aangesien dieet nie 'n effek op die groei, karkasgewig-verspreiding, waterhouvermoë, kleur, skeurwaardes of organoleptiese eienskappe van bokvleis gehad het nie, kan BB'e op 'n dieet met 'n laer ME-waarde as wat normaalweg vir skape geformuleer word, afgerond word, sonder om 'n verlaging in produksie te verwag. Dit mag 'n direkte ekonomiese voordeel vir afronding van BB'e in die voerkraal inhou. Vleis van jong voerkraalbokke is nie minderwaardig teenoor die van skape nie e-n dit het 'n hoër proteren- en laer vetpersentasie. Dus kan bokvleis as 'n gesonde voedselbron gesien word, veralonder lae-inkomste groepe of mense wat 'n lae kalorie-dieet wil inneem.
247

Breeding for Nitrogen Use Efficiency in Soft Red Winter Wheat

Hitz, Katlyn 01 January 2015 (has links)
Nitrogen use efficient (NUE) wheat varieties have potential to reduce input costs for growers, limit N runoff into water ways, and increase wheat adaptability to warmer environments. Previous studies have done little to explain the genetic basis for NUE and components, nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE). Four studies were conducted to 1) determine genotypic stability of NUE under high and low N regimes and under warming 2) determine effect of warming on NUE 3) indentify QTL associated with NUE components 4) assess the utility of canopy spectral reflectance (CSR) as a high-throughput phenotyping device for NUE. Genotypic response to N stress or warming varied. Uptake efficiency was found to be more important than utilization efficiency to genotypic performance under high and low N environments and under warming. Selection under low N for NUpE and under high N for NUtE most efficiently identified NUE varieties. Uptake and utilization were lower under warming due to quickened development. No strong correlations between the CSR indices and NUE existed. No QTL were found to be significantly associated with NUE components. Further research into the mechanisms controlling NUE and to reveal plant response to N stress and under warming is necessary.
248

Impacto da utilização de motores de alto rendimento e sua aplicação no leilão de eficiência energética. / Impact of the use of high performance engines and its application in the auction of energy efficiency.

Micerino, Fabio José 14 May 2012 (has links)
O trabalho apresentado tem como objetivo principal pesquisar e demonstrar através de simulações as implicações da utilização de motores de alto rendimento com viés de Eficiência Energética. Além disso, pretende-se estabelecer uma ligação entre o uso eficiente da energia com a possibilidade dos leilões de eficiência energética virem a se tornar uma realidade no Brasil. É de fundamental importância que se tenha a preocupação com sistemas de conservação de energia e não somente com novas fontes de geração. A eficiência Energética vem ganhando cada vez mais espaço no setor elétrico, se tornando muito mais que um indicador, mas também uma forma de tornar o sistema mais robusto e capaz de suprir deficiências por problemas estruturais. Procurou-se demonstrar o cenário atual da matriz energética atual, conceituar leilões de eficiência energética e os certificados brancos que é um subproduto deste. Por fim, realizou-se várias simulações estudando a substituição dos motores de alto rendimento e os ganhos técnicos e financeiros atrelados aos leilões de eficiência energética. Além disso, foi demonstrado também o impacto da utilização dos motores de alto rendimento em leilões de eficiência energética por segmentos da indústria brasileira. / The present study has as main objective the analysis, through simulations, of the implications of the use of energy efficient motors with a bias of energy Efficiency. In addition, we intend to establish a link between the efficient use of energy with the possibility of auctions for energy efficiency become a reality in Brazil. It is also important to have concerns with energy conservation systems and not only with new sources of generation. Energy efficiency is becoming an increasingly common concern in the electricity sector, being much more than an indicator but also a way to make the system more robust and capable of mitigating deficiencies which occur by structural problems. In this work we tried to present the current energy scenario and define the energy efficiency auctions as well as its byproduct, the white certificates. Finally, we carried out several simulations studying the replacement of common electrical motors by high efficiency ones in order to analyse the technical and the financial gains linked to energy efficiency auctions. In addition, we also demonstrated the impact of the use of high efficiency motors by sectors of brazilian industry in the energy efficiency auctions.
249

Impacto da utilização de motores de alto rendimento e sua aplicação no leilão de eficiência energética. / Impact of the use of high performance engines and its application in the auction of energy efficiency.

Fabio José Micerino 14 May 2012 (has links)
O trabalho apresentado tem como objetivo principal pesquisar e demonstrar através de simulações as implicações da utilização de motores de alto rendimento com viés de Eficiência Energética. Além disso, pretende-se estabelecer uma ligação entre o uso eficiente da energia com a possibilidade dos leilões de eficiência energética virem a se tornar uma realidade no Brasil. É de fundamental importância que se tenha a preocupação com sistemas de conservação de energia e não somente com novas fontes de geração. A eficiência Energética vem ganhando cada vez mais espaço no setor elétrico, se tornando muito mais que um indicador, mas também uma forma de tornar o sistema mais robusto e capaz de suprir deficiências por problemas estruturais. Procurou-se demonstrar o cenário atual da matriz energética atual, conceituar leilões de eficiência energética e os certificados brancos que é um subproduto deste. Por fim, realizou-se várias simulações estudando a substituição dos motores de alto rendimento e os ganhos técnicos e financeiros atrelados aos leilões de eficiência energética. Além disso, foi demonstrado também o impacto da utilização dos motores de alto rendimento em leilões de eficiência energética por segmentos da indústria brasileira. / The present study has as main objective the analysis, through simulations, of the implications of the use of energy efficient motors with a bias of energy Efficiency. In addition, we intend to establish a link between the efficient use of energy with the possibility of auctions for energy efficiency become a reality in Brazil. It is also important to have concerns with energy conservation systems and not only with new sources of generation. Energy efficiency is becoming an increasingly common concern in the electricity sector, being much more than an indicator but also a way to make the system more robust and capable of mitigating deficiencies which occur by structural problems. In this work we tried to present the current energy scenario and define the energy efficiency auctions as well as its byproduct, the white certificates. Finally, we carried out several simulations studying the replacement of common electrical motors by high efficiency ones in order to analyse the technical and the financial gains linked to energy efficiency auctions. In addition, we also demonstrated the impact of the use of high efficiency motors by sectors of brazilian industry in the energy efficiency auctions.
250

Site-level resource efficiency analysis

Gonzalez Hernandez, Ana January 2018 (has links)
To achieve agreed targets for reducing global carbon emissions, industry must become more resource-efficient. To this end, two viable strategies exist: energy efficiency and material efficiency. Despite their inherent interdependence, industry continues to treat these two strategies as isolated pursuits, providing in the process only a partial insight into the potential of resource efficiency. To resolve this disconnect, this thesis attempts to develop and apply tools that help integrate industrial energy and material efficiency analyses. Three areas of research are explored. The first is concerned with a fundamental component of industrial performance: efficiency benchmarks. No agreed-upon metric exists to measure the efficiency with which the sector trans- forms both energy and materials - that is, how resource-efficient they are. This thesis applies exergy - a well-established method to consolidate energy and materials into a single metric - to a case study of the global steel industry in 2010. Results show that this exergy-based metric provides a suitable proxy to capture the interactions between energy and materials. By comparing energy and material efficiency options on an equal footing, this metric encourages the recovery of material by-products - an intervention excluded from traditional energy efficiency metrics. To realise resource efficiency opportunities, individual industry firms must be able to identify them at actionable time-frames and scopes. Doing this hinges on understanding resources flows through entire systems, the most detailed knowledge of which resides in control data. No academic study was found to exploit control data to construct an integrated picture of resources that is representative of real operations. In the second research area, control data is extracted to track the resource flows and efficiency of a basic oxygen steel-making plant from TataSteel. This second case study highlights the plant's material efficiency options during operations. It does so by building close-to-real-time Sankey diagrams of resource flows (measured in units of exergy) for the entire plant and its constituent processes. Without the support of effective policies the new exergy approach is unlikely to be widely adopted in industry. By collating evidence from interviews and policy documents, the third area explores why the European Union's industrial energy and emissions policies do not incentivise material efficiency. Results suggest several contributing factors, including: the inadequacy of monitored indicators; an imposed policy lock-in; and the lack of a designated industry lobby and high-level political buy-in. Policy interventions are then proposed to help integrate material efficiency into energy and climate agendas. The European Union's limited agency stresses the need for Member States and industry to drive the move to a low-carbon industry in the short-term.

Page generated in 0.0806 seconds