Academic literature on the topic 'Draugar'

This essay deals with the concept of 'soul' in beliefs among north germanic pagans. As it comes forth in written sources, this concept can easely be seen as an odd contradiction, since the concept of 'soul' after the demise of a person seems to split. There seems to exist both an idea of different realms for the dead, and a thought that the dead would 'live' on in their graves. Some researchers, i.e. Price (2002) and Kaliff (1997), think that the soul of the dead human according to Nordic pagan belief split apart in a way, that there was an idea of the human soul being made up of several aspects, each with its own goal an purpose. Five such aspects have been identified - a protective free-soul, a personification of the inviduals luck (and possibly part of his/her destiny), a physical body or an aspect of the soul abilitating shape shifting, a persons thoughts and goals and very essence, and finally the dead body 'living' on in the burial mound. An alternative interpretation (i.e. Ellis 1968) is that the different explanations of the future of the dead are results of different traditions, connected to geographically and/or chronologically fixed ideas, but that certain remnants of earlier traditions could remain even when a new view of the afterlife has taken over. I have chosen to discuss these different viewpoints by comparing them with each other and with later swedish folklore, that is documented and seemingly originating during christian times. By peeling off views and beliefs of known christian origin, suprisingly well preserved representations of presumably older (pagan) views of the 'soul' and and its aspects have been identified. Furthermore, representations of soul aspects not yet described in connection with nordic paganism, and still not traceable to christian views, have been found. The result of the essay is that the theory of several soul aspects in pre-christian or pagan nordic beliefs seems to hold up best. Even if there, without a doubt, to some degree existed local variations and even though no tradition remains unchanged over time, it still would seem that the influence of these factors cannot in full explain the observed variation in views on soul aspects in pre-christian viking age Norse religion.

The number of horses in Ireland had shown remarkable consistency from 1861 until just before 1951. Between the end of the Second World War and 1951 there was a rapid decrease in the number of working horses, and the rate of the decrease accelerated during the decade of the 1950s and the early 1960s. Throughout the 1960s popular emphasis was placed on mechanisation, as if there were no role for the horse as a working animal. Even the production of pleasure horses seems to have been initially regarded as of little value. The 1970s were a sad period for both light and heavy draught horses in County Cork, as in the rest of Ireland. With increased mechanisation, the market for heavy draught animals which had previously dominated transport in the city of Cork, came to an end. There was a great danger that the Irish Draught would soon become extinct, so the formation of the Irish Draught Horse Society in 1976 was of great importance for the development of the Irish Draught as a breed. In 1982 this society published the "Breed Standard and Guideline", the first time that an official standard had been published for an Irish Draught. Despite various schemes during the 1980s and 1990s designed to increase the number and improve the quality of the Irish Draught horse population, it is, at the beginning of the 21st Century, one of the world's endangered breeds.

Thesis (MScEng)--Stellenbosch University, 2007.<br>ENGLISH ABSTRACT: A natural draught wet-cooling tower (NDWCT) was modelled using the Merkel method with an improved energy equation as recommended by Kloppers and Kroger (2005a) - referred to as the Improved Merkel method. The improved energy equation is used for calculating the heat rejection rate of the tower and includes the energy associated with water evaporation. The sensitivity indexes of a NDWCT were calculated numerically with the Improved Merkel method model. It was found that the perfonnance of a NDWCT is most sensitive to the fill Merkel number. The "Natklos" fill test facility at Stellenbosch University was used to estimate typical uncertainties found in fill performance characteristics. The zeroth order uncertainty for the Merkel number and loss coefficient was calculated to be 0.2100 m-1 and 0.4248 m- 1 , respectively, while the first order uncertainty for the Merkel number and loss coefficient was calculated to be 0.1933 m- 1 and 0.2008 m-1 , respectively. ASME requires that the uncertainty in tower capability has to be less than 6 % for a NDWCT perfonnance test to be deemed ASME approved. Propagating typical measurement uncertainties found in NDWCT test standards and experimental data into the tower capability showed that the 6 % uncertainty limit imposed by ASME is unrealistic and too stringent. Performance curve generator (PCG) is a software package developed that generates NDWCT perfonnance curves. With these performance curves it is possible to easily and effectively adjust the off-design test results in order to detennine whether the NDWCT has met its guarantee or not.<br>AFRIKAANSE OPSOMMING: Die werksverrigting van 'n natuurlike trek nat koeltoring (NTNT) is gemodelleer deur gebruik te maak van die Merkel metode met 'n verbeterde energie vergelyking, soos aanbeveel deur Kloppers en Kroger (2005a) - Verbeterde Merkel metode. Die energie vergelyking word gebruik om die toring se tempo van warmteoordrag te bereken en sluit die energieverlies as gevolg van verdamping in. Die Verbeterde Merkel metode model was gebruik om die sensitiwiteits-indekse van 'n NTNT te bepaal. Die analise toon dat die toring se werksverrigting die sensitiefste is vir die pakking se Merkel getal. Die Natklos pakkingstoetsfasiliteit aan die Universiteit van Stellenbosch was gebruik om tipiese onsekerheid in die pakkingsprestasiekarakteristieke te bepaal. Die zero-orde onsekerheid in die Merkel getal en verlieskoeffisient was bereken as 0.2100 m· 1 en 0.4248 m· 1 , onderskeidelik, terwyl die eerste-orde onsekerhede bereken was as 0.1933 m·1 en 0.2008 m· 1 , onderskeidelik. Die toelaatbare onsekerheid in toringvennoe vir 'n NTNT aanvaardingstoes volgens ASME is 6 %. Deur tipes meetonsekerhede, soos gegee deur NTNT aanvaardings-toesstandaarde sowel as eksperimentele data, deur te propageer, word 'n onsekerheid veel groter as die toelaatbare 6 % gegenereer. 'n Renekaarpakket, genaamd Performance Curve Generator (PCG), is ontwikkel om werksverrigtinskurwes vir 'n NTNT te genereer. PCG se werksverrigtinskurwes maak dit moonltik om maklik te bepaal of a NTNT sy ontwerpskriterea bereik het of nie.

Thesis (PhD)--Stellenbosch University, 2011.<br>ENGLISH ABSTRACT: Axial flow fan arrays form part of air-cooled steam condensers in direct drycooled power plants. This dissertation investigates the performance of axial flow fans when located at the perimeter of a fan array. The perimeter (or edge) fans may experience a reduction in air flow through the fan due to the prevalence of distorted inlet conditions upstream of the fan. The reduction in air flow leads to a reduction in the heat transfer capability of the steam condenser and a consequent reduction in the electricity output of the power plant. Due to the physical size of an air-cooled condenser, full-scale experiments are often impractical and computational fluid dynamics (CFD) is used to model its performance under various conditions. To limit the size of the CFD model the axial flow fans in the CFD analysis are represented by means of simplified methods. Three different simplified methods are presented and applied to a CFD model of a single axial flow fan, namely the pressure jump method (PJM), actuator disc method (ADM) and extended actuator disc method (EADM). The results are compared to experimental values. The comparison highlights the limitations of the models: The ADM fails to model fan performance correctly at low flow rates, while the PJM ignores the variation in fan blade properties at different locations within the fan rotor. The EADM is presented as an improvement on both the other two models. A multiple fan test facility is constructed, consisting of three 630 mm diameter fans extracting air from a common inlet chamber. The inlet chamber is constructed in such a way that one of the three fans act as the perimeter (edge) fan. The floor of the inlet chamber can be adjusted to increase or reduce the inlet flow distortion experienced by the edge fan. Six different fan configurations are tested in the position of the edge fan and an empirical method is derived by which the volumetric effectiveness of an edge fan can be predicted. The experimental results are compared to CFD results for the same facility using the three different simplified simulation methods investigated previously. Particle image velocimetry (PIV) measurements are also performed upstream of the edge fan and the velocity profiles at the inlet of the fan are compared to the profiles obtained numerically. The comparisons show that the EADM predicts the performance of the edge fan more accurately than the ADM en PJM. The effect of adding a walkway and removing the bell mouth upstream of the edge fan was investigated using the EADM. The results are used to show the location of the loss mechanisms upstream of the edge fan. The addition of a walkway moves the location of the pressure loss away from the edge fan bell mouth towards the edge of the walkway. Consequently the distortion directly upstream of the edge fan is reduced and its volumetric effectiveness increased. The effect of removing the edge fan’s bell mouth is similar to the effect of adding a walkway upstream of the edge fan.<br>AFRIKAANSE OPSOMMING: Aksiaalwaaiermatrikse vorm deel van lugverkoelde kondensors in direk droëverkoelde kragstasies. Hierdie verhandeling ondersoek die werkverrigting van aksiaalwaaiers wat geleë is op die rand van ‘n groot waaiermatriks. Die randwaaiers kan ’n vermindering in deurvloei ondervind as gevolg van versteurde inlaattoestande stroom-op vanaf die waaier. Die vermindering in lugvloei lei tot ’n vermindering in die warmetoordagvermoë van die stoomkondensor en ’n gepaardgaande afname in die elektrisiteitslewering van die kragstasie. As gevolg van die fisiese grootte van die lugverkoelde kondensor is volskaalse eksperimente gewoonlik onprakties en word berekeningsvloeimeganika (BVM) gebruik om die werking van die aanleg onder verskeie toestande te modelleer. Ten einde die grootte van die BVM model te beperk, word die aksiaalwaaiers in so ‘n BVM analiese voorgestel met behulp van vereenvoudigde metodes. Drie verskillende vereenvoudigde metodes word aangebied en toegepas op ‘n BVM model van ‘n enkelwaaier, naamlik die druksprongmetode, die aksieskyfmetode en die verlengde aksieskyfmetode. Die resultate word vergelyk met eksperimentele waardes. Die vergelyking benadruk die beperkings van die modelle: Die aksieskyfmetode kan nie die werking van die waaier akkuraat voorspel by lae vloeie nie en die druksprongmetode ignoreer die variasie in lemeienskappe op verskillende liggings binne-in die waaierrotor. Die verlengde aksieskyfmetode word voorgestel as ‘n verbetering op die ander twee metodes. ‘n Veelvuldige waaiertoetsfasiliteit is saamgestel, bestaande uit drie 630 mm deursnee waaiers wat lug uit ’n gemeenskaplike inlaatkamer suig. Die inlaatkamer is so saamgestel dat een van die waaiers in die fasiliteit ‘n randwaaier verteenwoordig. Die vloerhoogte van die inlaatkamer kan aangepas word om die inlaatversteuring wat deur die raandwaaier ondervind word te vermeerder of te verminder. Ses verskillende waaierkonfigurasies is getoets in die randwaaierposisie. ‘n Empiriese metode waarmee die volumetriese effektiwiteit van ‘n randwaaier voorspel kan word is afgelei. Die eksperimentele resultate word vergelyk met ooreenstemmende BVM resultate vir dieselfde fasiliteit deur gebruik te maak van die drie verskillende vereenvoudigde metodes wat vroeër ondersoek is. Partikelbeeld snelheidsmetings word ook stroom-op vanaf die randwaaier uitgevoer en die snelheidsprofiele by die inlaat van die waaier word vergelyk met profiele wat numeries bereken word. Die vergelykings wys dat die verlengde aksieskyfmetode die werkverrigting van ’n aksiaalwaaier meer akkuraat voorspel as die aksieskyf- of druksprongmetodes. Die effek van die installering van ‘n loopvlak en die verwydering van die randwaaier se inlaatmondstuk word ondersoek met behulp van BVM deur gebruik te maak van die verlengde aksieskyfmetode. Die resultate word spesifiek gebruik om die ligging van die verliesmeganismes stroom-op vanaf die randwaaier aan te dui. Die resultate wys dat die installering van ‘n loopvlak die ligging van die drukverlies wegneem vanaf die rand van die waaierinlaat na die rand van die loopvlak. Dit verminder die inlaatversteuring stroom-op vanaf die randwaaier en die volumetriese effektiwiteit word verhoog. Die verwydering van die randwaaier se inlaatmondstuk het ‘n soortgelyke effek as die installering van ‘n loopvlak stroom-op vanaf die randwaaier.

Thesis (PhD) -- University of Stellenbosch, 2010.<br>ENGLISH ABSTRACT: In the design of a modern natural draught wet-cooling tower (NDWCT), structural and performance characteristics must be considered. Air flow distortions and resistances must be minimised to achieve optimal cooling which requires that the cooling towers must be modelled two-dimensionally and ultimately threedimensionally to be optimised. CFD models in literature are found to be limited to counterflow cooling towers packed with film fill, which is porous in one direction only and generally has a high pressure drop, as well as purely crossflow cooling towers packed with splash fill. This simplifies the analysis considerably as the effects of flow separation at the air inlet are minimised and fill performance is determined using the method of analysis originally employed to determine the fill performance characteristics from test data. Many counterflow cooling towers are, however, packed with trickle and splash fills which have anisotropic flow resistances, which means the fills are porous in all flow directions and thus air flow can be oblique through the fill, particularly near the cooling tower air inlet. This provides a challenge since available fill test facilities and subsequently fill performance characteristics are limited to purely counter- and crossflow configuration. In this thesis, a CFD model is developed to predict the performance of NDWCTs with any type of spray, fill and rain zone configuration, using the commercial code FLUENT®. This model can be used to investigate the effects of different: atmospheric temperature and humidity profiles, air inlet and outlet geometries, air inlet heights, rain zone drop size distributions, spray zone performance characteristics, variations in radial water loading and fill depth, and fill configurations or combinations on cooling tower performance, for optimisation purposes. Furthermore the effects of damage or removal of fill in annular sections and boiler flue gas discharge in the centre of the tower can be investigated. The CFD modelling of NDWCTs presents various options and challenges, which needed to be understood and evaluated systematically prior to the development of a CFD model for a complete cooling tower. The main areas that were investigated are: spray and rain zone performance modelling by means of an Euler-Lagrangian model; modelling of air flow patterns and flow losses; modelling of fill performance for oblique air flow; modelling of air pressure and temperature profiles outside and inside the cooling tower. The final CFD results for the NDWCT are validated by means of corresponding one-dimensional computational model data and it is found that the performance of typical NDWCTs can be enhanced significantly by including protruding platforms or roundings at the air inlet, reducing the mean drop size in the rain zone, radially varying the fill depth and reducing the air inlet height.<br>AFRIKAANSE OPSOMMING: By die ontwerp van ‘n moderne natuurlike trek nat koeltoring (NTNK), moet strukturele en werkverrigtings eienskappe in ag geneem word. Wanverdeelde lugvloei en vloeiweerstande moet geminimaliseer word om optimale verkoeling te bewerkstellig, wat vereis dat die koeltorings twee-dimensioneel en uiteindelik driedimensioneel gemodelleer moet word om hulle te kan optimeer. Dit is gevind dat berekeningsvloeidinamika (BVD of “CFD” in engels) modelle in die literatuur, beperk is tot teenvloei koeltorings gepak met film tipe pakking, wat net in een vloeirigting poreus is en boonop gewoonlik ook ‘n hoë drukval het, sowel as suiwer dwarsvloei koeltorings met spatpakking. Hierdie vergemaklik die analise aansienlik omdat die effekte van vloeiwegbreking by die luginlaat verklein word en die pakking se werkverrigtingsvermoë bereken kan word met die analise metode wat oorspronklik gebruik is om die pakkingseienskappe vanaf toets data te bepaal. Baie teenvloei koeltorings het egter drup- (“trickle”) of spatpakkings met anisotropiese vloeiweerstand, wat beteken dat die pakking poreus is in alle vloeirigtings en dat die lug dus skuins deur die pakking kan vloei, veral naby die koeltoring se lug inlaat. Hierdie verskaf ‘n uitdaging aangesien beskikbare pakking toetsfasiliteite, en dus ook pakking karakteristieke, beperk is tot suiwer teenvloei en dwarsvloei konfigurasie. ‘n BVD model word in hierdie tesis ontwikkel wat die werkverrigtingsvermoë van NTNK’s kan voorspel vir enige sproei, pakking en reënsone konfigurasie deur van die kommersiële sagteware FLUENT® gebruik te maak. Hierdie model kan gebruik word om die effekte van verskillende: atmosferiese temperatuur- en humiditeitsprofiele, lug inlaat en uitlaat geometrië, lug inlaat hoogtes, reënsone druppelgrootteverdelings, sproeisone werkverrigtingskarakteristieke, variasie in radiale waterbelading en pakking hoogte, en pakking konfigurasies of kombinasies op koeltoringvermoë te ondersoek vir optimerings doeleindes. Verder kan die effekte van beskadiging of verwydering van pakking in annulêre segmente, en insluiting van ‘n stoomketel skoorsteen in die middel van die toring ondersoek word. Die BVD modellering van NTNK bied verskeie moontlikhede en uitdagings, wat eers verstaan en sistematies ondersoek moes word, voordat ‘n BVD model van ‘n algehele NTNK ontwikkel kon word. Die hoof areas wat ondersoek is, is: sproeien reënsone modellering mbv ‘n Euler-Lagrange model; modellering van lugvloeipatrone en vloeiverliese; modellering van pakking verrigting vir skuins lugvloeie; modellering van lugdruk- en temperatuurprofiele buite en binne in die koeltoring. Die BVD resultate word mbv van data van ‘n ooreenstemmende eendimensionele berekeningsmodel bevestig en dit is bevind dat die werkverrigting van ‘n tipiese NTNK beduidend verbeter kan word deur: platforms wat uitstaan of rondings by die luginlaat te installeer, die duppelgrootte in die reënsone te verklein, die pakkingshoogte radiaal te verander, en die luginlaathoogte te verlaag.

The aim of this work was improve and validate the Oxylog portable oxygen consumption meter for use with draught ruminants, and to test its ability to estimate the energy expenditure of these animals in the field. Few data were available on the energy costs of the various tasks that draught ruminants perform and it was expected that the calorific factors established during laboratory experiments may not necessarily reflect the energy consumption during field work with farmers. This could have important implications in the establishment of the nutritional requirements of draught ruminants. A review of the literature on the various techniques and instruments available for the field measurement of energy consumption was carried out. A new facemask for use with the Oxylog was designed and the Oxylog equipment with this mask was validated against the open circuit gas analysis system available at the Centre for Tropical Veterinary Medicine in Edinburgh. It was found that the Oxylog on average over-estimated oxygen consumption, as measured by the gas analysis system, by 1.5%. In the second experiment, carried out with buffaloes and oxen pulling carts on the Unipalma oil-palm plantation in Meta, Colombia, the modified Oxylog system was tested in the field. Technically, the method worked satisfactorily, although the small digital displays on the Oxylog were difficult to read, and the measurements obtained generally agreed with the more established calculation methods of estimating energy consumption. It was concluded that the use of the modified Oxylog was an accurate and reliable method for the estimation of energy expenditure in the field.

This thesis considers the making and circulation of drawn and printed imagery in Britain over the period 1610-1750 with a particular emphasis on the observation and record of place. It takes as its focus the contested position of the visual image in Britain over this period, considering the place of the record of the land, past, present and future, in the making and re-making of the country. It is particularly concerned to elucidate links between different forms of depictive practice: ‘pictorial’ and ‘mathematical’, evident at the time of their making, if often lost in their interpretation in the modern literature. These depictive traditions are explored in order to examine the value of the categories of ‘real’ and ‘ideal’ that have tended to dominate narratives of landscape history. Throughout, drawings and prints are considered as forms of knowledge that combined a number of traditions and practices, aged along with those more recent. Tensions between theories and practices of image-making are central rather than incidental to the study, discovered through an examination of manuals and treatises as well as drawings and prints. There is also a recognition of the importance of collecting practices and patronage over this period, explored through the extended legacies of Lord Thomas Howard, Earl of Arundel. A focus on collections and the legacies of landscape imagery has necessitated that images be brought together from a wide range of regional and metropolitan libraries, archives and art galleries, and reconnected with the wider cultural, political and religious worlds through which they were circulated and enacted at the time of their making. Drawing on a number of disciplinary traditions, this approach offers a new perspective on topographically-informed imagery over this extended period, seeking to expand the parameters of the interpretation of such works.

The interactions of disease, work and undernutrition in draught animals were examined in three separate studies. The first study carried out in Indonesia investigated the effects of <I>Trypanosoma evansi </I>on the work output of twelve swamp buffalo in two groups. The second undertaken in the UK, used four groups of six sheep as a model to examine the effects of exercise and plane of nutrition on cellular and humoral immune responses in the absence of a pathogen. The final study in The Gambia, looked at the effects of work and undernutrition on the trypanotolerance of 32 N'Dama cattle in four groups challenged with <I>T. congolense. </I>In the first experiment work output was monitored for 11 weeks in infected and uninfected animals using a cross-over design. In the second laboratory based experiment the immune responses of sheep challenged with two foreign antigens, <I>Brucella abortus </I>and ovalbumin, were measured for 11 weeks after challenge in a factorial design with two planes of nutrition and two levels of exercise. In the third study the same factor design was adopted to examine the effects of work and undernutrition on the trypanotolerance of N'Dama cattle challenged with <I>T. congolense. </I>The results of all three studies were analysed using both parametric and non-parametric statistical tests as appropriate. In the first experiment carried out in Indonesia after a protracted period of work (5 weeks pre-infection and 4 weeks post-infection), the parasitaemias of some infected buffalo increased dramatically and this was associated with a marked decline in work output. In the second study with sheep, immune responses varied markedly between individuals but there were no significant differences between groups, with one exception, the speed of the primary antibody response to ovalbumin was significantly faster in sheep on the high plane of nutrition than in those on the low plane. In the final study work caused significant increases in animal parasitaemias and reductions in blood packed cell volumes. Some of the working cattle became so severely anaemic (PCVs < 15%) that they were unable to complete the normal daily work programme and had to be retired early, the first after only seven weeks work. In conclusion it appears that in some circumstances work can affect the course of a disease and conversely diseases can reduce work output. It is however very difficult to quantify these effects because of large differences in response between individual animals and differences in pathogenicity between different diseases and different strains of the same disease.

A literature review was conducted on several models which have been developed, based on Terzaghi's passive earth pressure theory, to describe the forces acting upon tillage implements during tillage operations. These models require a knowledge of cohesion (c) and angle of internal shearing resistance (cp) data which are not easy to obtain especially in remote areas. The main objective of the study was to establish a prediction model for the draught force required for a range of primary tillage implements under different field and soil conditions. The data obtained from the model were used to investigate whether the model was adequate for the mechanisation planning of the GAP region (South Eastern Anatolia Integrated Development Project) in Tiirkiye where by the year 2012, approximately 1.7 million ha ofland will be opened to irrigation. An effective three-point linkage dynamometer system was developed to measure the draught of implements under different soil conditions. The system consists of bi-axial Linkage Extended Octagonal Ring Transducers (LEORTs) for the lower links, a modified top link and a rotary position transducer sensing the angle of the crossshaft, together with a 21x datalogger and a portable computer. All transducers outputs were repeatable and linear with a co'efficient of determination of ~ 0.999. The output hysteresis effect was small for all transducers; the largest deviation from the mean was 1.006 % [f.s.] which occurred in the top link. Cross-sensitivity errors for the LEORTs were not significant at a maximum of 0.001 J.lV V-IN-I. A spreadsheet model was developed in order to download the data from the instrumentation system to the computer. The model is user friendly and can be used to calculate and plot the forces on the linkage system. Field experiments were conducted to determine draught force requirements of tillage implements such as a disc plough, mouldboard plough, chisel and subsoiler both under sandy loam soil conditions in UK and clay soil conditions in Tiirkiye. The standard tine which has a 450 rake angle was used as a reference tine. The field tests were Gonducted to examine the validation of a model for different soil conditions in UK such as dry, wet, light and heavy soil conditions.