International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The future of range operations in the area of expendable launch vehicle (ELV) support is unquestionably headed in the direction of space-based rather than land- or air-based assets for such functions as metric tracking or telemetry data collection. To this end, an effort was recently completed by the Air Force’s Eastern Range (ER) to certify NASA’s Tracking and Data Relay Satellite System (TDRSS) as a viable and operational asset to be used for telemetry coverage during future Titan IV/Centaur launches. The test plan developed to demonstrate this capability consisted of three parts: 1) a bit error rate test; 2) a bit-by-bit compare of data recorded via conventional means vice the TDRSS network while the vehicle was radiating in a fixed position from the pad; and 3) an in-flight demonstration to ensure positive radio frequency (RF) link and usable data during critical periods of telemetry collection. The subsequent approval by the Air Force of this approach allows future launch vehicle contractors a relatively inexpensive and reliable means of telemetry data collection even when launch trajectories are out of sight of land-based assets or when land- or aircraft-based assets are not available for support.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Telemetry support has been a component of the instrumentation test support structure at Kwajalein Missile Range (KMR) for nearly 40 years. From a limited initial suite of manually pointed telemetry antennas, the Range has grown to include nine tracking antennas and four fixed receiving antennas. This paper describes the current modernization program at KMR that will include nine new telemetry trackers and five fixed antennas that will be networked and controlled via fiber optic links from a newly established telemetry control center on the island of Kwajalein. These upgrades will reduce operational cost and institute efficiencies, while continuing to meet Range Users’ growing requirements.

Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT:In this thesis we discuss some of the anomalies present in systems with long-range interactions, for instance negative speci c heat and negative magnetic susceptibility, and show how they can be related to the convexity properties of the thermodynamic potentials and nonequivalence of ensembles. We also discuss the possibility of engineering long-range quantum spin systems with cold atoms in optical lattices to experimentally verify the existence of nonequivalence of ensembles. We then formulate an expression for the density of states when the energy and magnetisation correspond to a pair of non-commuting operators. Finally we analytically compute the entropy s( ;m) as a function of energy, , and magnetisation, m, for the anisotropic Heisenberg model with Curie-Weiss type interactions. The results show that the entropy is non-concave in terms of magnetisation under certain circumstances which in turn indicates that the microcanonical and canonical ensembles are not equivalent and that the magnetic susceptibility is negative. After making an appropriate change of variables we show that a second-order phase transition can be present at negative temperatures in the microcanonical ensemble which cannot be represented in the canonical ensemble. / AFRIKAANSE OPSOMMING: In hierdie tesis bespreek ons van die onverwagte eienskappe wat sisteme met lang afstand wisselwerkings kan openbaar, byvoorbeeld negatiewe spesi eke warmte en negatiewe magnetiese suseptibiliteit. Ons dui ook die ooreenkoms tussen hierdie gedrag en die konveksiteit van die termodinamiese potensiale en nie-ekwivalente ensembles aan. Hierna bespreek ons die moontlikheid om lang afstand kwantum spin sisteme te realiseer met koue atome in 'n optiese rooster. Daarna wys ons hoe dit moontlik is om 'n uitdrukking vir die digtheid van toestande te formuleer vir sisteme waar die energie en magnetisasie ooreenstem met operatore wat nie met mekaar kommuteer nie. Uiteindelik bepaal ons die entropie, s( ;m), in terme van die energie, , en magnetisasie, m, vir die anisotropiese Heisenberg model met Curie-Weiss tipe interaksies. Die resultate wys dat die entropie onder sekere omstandighede nie konkaaf in terme van magnetisasie is nie. Dit, op sy beurt, dui aan dat die mikrokanoniese en kanoniese ensembles nie ekwivalent is nie en dat die magnetiese suseptibiliteit negatief kan wees. Nadat ons 'n toepaslike transformasie van veranderlikes maak, wys ons dat 'n tweede orde fase-oorgang by negatiewe temperature kan plaasvind in die mikrokanoniese ensemble wat nie verteenwoordig kan word in die kanoniese ensemble nie.

Thesis (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: This project aimed at enhancing the net benefit in production systems. It took a holistic approach to evaluate the potential interactions of herbaceous legumes in relation to weed dynamics, soil fertility and livestock management in the crop-livestock system in Nigeria. The project was carried out between 2000 and 2002 in two localities. These were the National Animal Production Research Institute (NAPRI) at Zaria in the northern Guinea savannah and the International Institute of Tropical Agriculture (IITA) at Ibadan in the derived savannah. The main experiment was carried out in the northern Guinea savannah, while the secondary experiments were simultaneously conducted in the derived savannah and the northern Guinea savannah. The experimental design for the three experiments reported in this thesis is a splitsplit plot, fitted into randomised complete block design (RCBD), with four replications. Main plot treatments were herbaceous legumes, namely Vigna unguiculata, Arachis hypogaea, Glycine max, Aeschynomene bistrix, Centrosema pascuorum, Stylosanthes guianensis and natural vegetation. Sub-plot treatments were management systems (1) M1, 'residues left in the field'; (2) M2, 'residues taken out of the field' and (3) M3, 'residues fed to livestock, manure/urine/refused feeds returned'. Sub-plot treatments were administered in a sequence following rotational fallows of herbaceous legumes and natural vegetation. However, plots in the secondary experiments were not subdivided before the cropping of maize in 2002, and for logistical reasons only two sub-plot treatments, M1and M2, are featured in this experiment. Herbaceous legumes were established at the start of the rainy season, approximately in June, in 2000, 2001 and 2002. All herbaceous legumes received single super phosphate (SSP) at 20kg ha" P20S at planting, while minimum hand weeding was done to maintain pure legume stands during the establishment phase. Forage biomass was higher in the derived savannah than in the northern Guinea savannah. Similarly, higher forage yields were observed after two consecutive years of legume fallow and natural vegetation, compared to the first year plots. Grain yield for Glycine max was consistently higher than for the other two grain legumes in 2001 and 2002. Chemical analysis of herbaceous legumes and natural vegetation showed that crude protein values ranged between 11.2% to 17.3% for legumes; that was significantly (p<0.05) higher than the 8.6% value found for natural vegetation. Moreover, all herbaceous legumes and natural vegetation, except Arachis hypogaea, had dry matter digestibility values of more than 30%. Maize grain and stover yields on herbaceous legumes fallowed plots were evaluated and compared with those for natural vegetation. Results in 2001, i.e. after a one-year fallow with legumes, indicated that the dry matter of maize grain and stover yields in the Stylosanthes guianensis plots were higher among the forage legumes. Arachis hypogaea gave the highest grain and stover yields among the grain legumes in the northern Guinea savannah. Results in 2002, i.e. after a two-year fallow, also showed that the productivity of maize planted on Arachis hypogaea and Glycine max fallowed plots were consistently higher across the three management systems tested in the Centrosema pascuorum, Glycine max, Aeschynomene histrix, Vigna unguiculata and least weight gain was recorded for the natural vegetation. Objective functions in linear optimisation, or linear combinations in algebra, used to link dynamic processes in livestock production (Iiveweight gain) with the dynamic processes in soils (soil nitrogen), weeds (weed biomass), herbaceous legumes (legume biomass) and crop production (maize grain and stover yields) under varying management systems took the form: Management system 1, Y, = f (XI, Xz, x4); Yr= 0 Management system 2, Y, = f (x" x2); Yz = 0 Management system 3, Y, = f (XI, Xz, xl); Yz= f (XI, Xz, X4. x5) Where (1) (2) (3) Y1 = Crop in kg; Y2 = Livestock weight gain in kg; X1= Weed in kg; X2 = Soil N g kg-1; X3 = Livestock compost in kg; N= Herbaceous legumes in kg; X5 = Maize stover in kg, for the three management systems considered in this experiment. Deductions from these equations showed that Aeschynomene histrix performed better under M1, i.e. when legumes residues were left on the field. Natural vegetation performed better than the herbaceous legumes under M2, i.e. when legumes residues were exported out of the field. However, the presence of manure in M3 enhanced soil fertility in the system and improved the overall productivity across all the legumes and natural vegetation. Overall rankings, conducted by pooling all components in the system, indicated that Glycine max performed best among the legumes, followed by Stylosanthes guianensis and Arachis hypogaea, which ranked second and viithird respectively. In relation to the specific legume groups, Stylosanthes guianensis performed better than the other two forage legumes, while Glycine max also performed better than the other two grain legumes tested. We can see from these on-station research results that there are indications of positive opportunities for improving overall productivity and resources. This can be done through integrating and complementing crop and livestock production, to provide a sustainable intensification of agriculture. / AFRIKAANSE OPSOMMING: Die studie is uitgevoer om die potensiële wisselwerking van kruidagtige peulplante met onkruiddinamika, grondvrugbaarheid en veebestuur te evalueer. Die hoofeksperiment in die "Northern Guinea Savannah" is vanaf 2000 tot 2002 uitgevoer by die "National Animal Production Research Institute" (NAPRI) in Zaria, Nigerië. Die twee sekondêre eksperimente is gelyktydig in Zaria en by die "International Institute of Tropical Agriculture" (liTA) naby Ibadan in die "Derived Savannah" uitgevoer. Die eksperimentele ontwerp was 'n dubbel gesplete perseelontwerp gepas in 'n volledig ewekansige blokontwerp met vier herhalings. Die hoofkomponente was die kruidagtige peulplante naamlik: Vigna unguiculata, Arachis hypogaea, Glycine max, Aeschynomene histrix, Centrosema pascuorum, Stylosanthes guianensis en natuurlike plantegroei. Die gekose peulplante is potensieel aangepas vir uiteenlopende omgewings en word dikwels na verwys as "'n mandjie van opsies". Subperseel behandelings was (1) peulplant gevestig en gelaat op die land - M1; (2) peulplant gevestig, geoes en weggeneem uit die land M2 en (3) peulplant gevestig, geoes, vir vee gevoer, mis/urine/vermorste voer terug na die land - M3. Die dubbel gesplete perseel behandelings is toegedien in 'n sekere volgorde nadat die peulplant rusoes/braak toegepas is. In die eerste jaar is die kruidagtige peulplante geplant op die hoofperseel van 25m by Sam. In die tweede jaar is die hoofperseel verdeel in twee persele waar onderskeidelik peulplante en mielies gevestig is terwyl daar in die derde jaar 'n verdere verdeling was wat gelei het tot verskillende gewasrotasiestelsels, nl. Peulplant-peulplant-mielies, peulplant-mielies-peulplant en peulplant-mielies-mielies. Parameters wat insluit planthoogte, -wydte en persentasie grondbedekking van die kruidagtige peulplante is tweeweekliks gemeet op vier 1M2 persele wat ewekansig oor elke hoofperseel versprei is in beide gebiede waar die studie uitgevoer is. Resultate het getoon dat die kruidagtige peulplante wat getoets is potensiële kandidate is vir insluitings in gewas/weiding rotasiesteiseis. Alhoewel voerproduksie hoër was in die "derived savannah" as in die "northern Guinea savannah", het die prestasie van die peulplante in die noordelike savannah gevarieer met die gewasproduksiestelsels. Hoër opbrengste is gerealiseer na twee opeenvolgende jare van oesrus met peulplante vergeleke met die eerste jaar waar daar geen residuele effek van die peulplante was nie, en die laaste jaar wat deur 'n mielie-oes voorafgegaan is. Biomassa opbrengste na twee jaar van aanhoudende verbouiing was die hoogste vir S. guianensis en die laagste vir A. hypogea. Ruproteien inhoud van die kruidagtige peulplante het gewissel van 170 g kg-1 DM in A. hypogea tot 62.4 g kg-1 DM in A histrix. Graanproduksie deur G. max was deurlopend hoër in 2001 en 2002 vergeleke met die twee ander graanproduserende peulplante nl. V. unguiculata en A. hypogea. Die voerproduksie in 2002 was heelwat hoër as die vorige jaar. Rotasie effekte op mieliegraan en oesreste na peulplante is vergelyk oor die dubbel gesplete persele (areas met verskillende oesruslengtes) om die ximplikasies van hulle residuele effek op grondvrugbaarheid verbetering en onkruid dinamika te bepaal. Mielie-opbrengs na een jaar van rusoes toon hoër waardes op persele wat onder kruidagtige peulplante was vergeleke met natuurlike plantegroei. Net so was die opbrengs deurlopend hoër op persele waar daar graan peulplante was as waar daar voer peulplante was. Oor die algemeen was die waardes hoër vir G. max, gevolg deur A. hypogea, A. histrix, C. pascuorum, V. unguiculata, S. guianensis en die laagste vir natuurlike plantegroei. In terme van die bestuurstelsels, het persele wat kompos ontvang het (M3) beter as die ander twee bestuurstelsels presteer (2.6 Mg ha" mieliegraan). Produksie van mieliegraan en oesreste na twee opeenvolgende jare van mielieverbouing was die hoogste na G. max (7.2 Mg ha" mieliegraan), gevolg deur die A. histrix perseel en die laagste op S. guianensis persele. Algemene waarnemings oor die twee subpersele wat met mielies beplant was in 2002 het getoon dat mielies beter presteer het op persele wat twee opeenvolgende jare met peulplante beplant was. Onkruidsamestelling en verspreiding is in beide die peulplante en natuurlike plantegroei gemeet. Grond vir saadbankontledings is op diagonale transekte in 0.5m by 0.5m kwadrate gemonster. Grondmonsters is ge-analiseer vir pH, totale stikstof, organiese koolstof, fosfor, kalsium en magnesium. Hierdie parameters is gebruik in 'n meervoudige regressie ontleding om hulle effek op onkruidspesievoorkoms te bepaal. Onkruidgetalle in lande na In rusoes het In deurlopende hoër vlak van besmetting getoon op die natuurlike plantegroei persele as op die peulplant persele. Die prestasie in terme van onkruidonderdrukking was in dalende volgorde: S. guianensis, C. pascuorum, V. ungucuilata, G. max, A. hypogaea en A. histrix. Die onkruidsamestelling het verskilonder die verskillende behandelings en dit het ook met tyd verander in dieselfde behandelings. In Bykomende eksperiment met die peulplante is uitgevoer om hulle effek op inname en groei van skape, asook die effek op kompos wat gemaak is van vermorste materiaal en uitskeidings van die skape, te bepaal. Droë materiaal verteerbaarheid was hoog vir S guianensis, G. max en A. histrix terwyl die laagste syfer verkry is by A. hypogea (177.6 g kg-1 DM). Ramme wat met kruidagtige peulplante gevoer is het beter presteer as die wat met natuurlike plantegroei gevoer is. Ramme wat met A. hypogaea gevoer is, het In gemiddelde daaglikse toename (GOT) getoon van 85.7 g daq", gevolg deur S. guianensis, C. pascuorum, G. max, A. histrix, V. unguiculata en laaste natuurlike plantegroei. Bykomende ontledings was gemik daarop om objektiewe funksies af te lei om dinamiese prosesse in vee (massatoename) met dinamiese prosesse in grond (grond N), onkruid (onkruidmassa), kruidagtige peulplante (peulplantmassa) en mielies (mieliegraan en oesreste massas) onder verskillende bestuurstelsels te verbind. In In poging om objektiewe funksies xiivan die verskillende komponente van die studie te bepaal, is die volgende lineêre funksies vir die drie bestuurstelsels oorweeg nl. Bestuurstelsel1. Yl = f (Xl, xz, x.); Yz= 0 Bestuurstelsel 2, Yl = f (Xl, Xz); Yz= 0 Bestuurstelsel3, Yl = f (Xl, X2, Xl); Yz= f (Xl. Xz. x.. les) Waar (1) (2) (3) Y1 = Oesopbrengs in kg; Y2 = Daaglikse massatoename in kg; X1 = Onkruidmassa in kg; X2 = Grond N in g kg-1 ; X3 = Kompos in kg; X4 = Kruidagtige peulplante in kg; X5 = Mieliereste in kg. Onder bestuurstelsel 1, het A. histrix beter as die ander gewasse presteer, terwyl natuurlike veld beter presteer het onder bestuurstelsel 2. Dit is 'n aanduiding dat bestuurstelsel 2 nie volhoubaar is nie. Die derde bestuurstelsel verteenwoordig volle integrasie van gewas en vee produksiestelsels. Die teenwoordigheid van mis in die stelsel het grondvrugbaarheid verbeter en algemene produktiwiteit verbeter. Hierdie resultate dui aan dat daar geleenthede is om algemene produktiwiteit te verbeter deur integrasie en komplementering van gewas- en veeproduksiestelsels om volhoubare intensifikasie van landbou te bereik.

Thesis (MScConEcol )--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Over 70% of South Africa is too arid for crop farming and is used for commercial livestock ranching, communal livestock ranching, or game ranching. These management systems differ from each other in a number of aspects, e.g. herbivore species, stocking rate, grazing regime, and management structure. The main question addressed in this study is: to what extent do the three management systems affect rangeland condition? Following the equilibrium paradigm of vegetation dynamics, communal livestock ranches are expected to have a greater detrimental effect on rangeland condition than other management systems because stocking densities and, consequently, herbivore impacts, are usually far higher than under the other two management systems. However, recent nonequilibrium theories argue that vegetation dynamics in arid systems are mainly driven by rare and stochastic rainfall events. Biotic factors, such as grazing and herbivore diversity, are predicted to have little effect on rangeland condition. This leads to the prediction that herbivore impacts on arid ecosystems are not density-dependent and, consequently, the high stocking densities commonly recorded on communal livestock ranches will not cause more rangeland degradation than other management systems. Arid and semi-arid rangelands are characterised by high inherent spatial and temporal variation in vegetation and soil parameters. Hence, differentiating between the effects of grazing management systems and natural variability caused by abiotic factors, such as rainfall, is difficult. This problem can be circumvented by examining gradients of grazing intensity radiating from water-points (= piospheres). I examined changes in vegetation and soil parameters along 500 m-Iong grazing gradients on ranches in the semi-arid Northem Cape province, South Africa, with the three abovementioned management systems. Analysis of the vegetation on these ranches demonstrated the existence of grazing gradients around the water-points. Two characteristic zones described in other studies were identified, namely the sacrifice zone (almost complete denudation of the vegetation close to the water-point) and the dense shrub zone (distal to the sacrifice zone). Communal livestock ranching had a greater negative effect on rangeland vegetation than the two other ranching systems, particularly with regard to annual grass species diversity, percentage of bare soil, and shrub density. Within 100 m of the water-points, soil quality was negatively affected by commercial cattle ranching. Contrastingly, there were no significant effects of the other two management systems on soil quality in the piosphere. The feeding of supplemental forage and nutrients may explain the greater impact of commercial cattle farming on soil quality. The results of this study are consistent with the predictions of the equilibrium theory of vegetation dynamics because grazing impacts were density-dependent in these semi-arid rangelands. However, the results presented here also indicate that forage supplementation alters the spatial and temporal distribution of livestock in a manner that may have greater negative impacts on soil quality than density of livestock per se. / AFRIKAANSE OPSOMMING: Meer as 70% van Suid-Afrika is te droog vir gewasverbouing en word gebruik vir kommersiële veeboerdery, gemeenskaplike veeboerdery of wildboerdery. Die bestuur van dié verskillende boerderytipes verskil wesentlik van mekaar in verskeie opsigte, ondermeer herbivoorspesies, veeaanskaffingstempo, weidingstipe en bestuurstruktuur. Die belangrikste vraag wat aangespreek word in die studie is die volgende: Tot watter mate affekteer die drie verskillende boerderybestuurstipes die toestand van weivelde? Gesien teen die agtergrond van die ekwilibriumparadigma van plantedinamika, word verwag dat gemeenskaplike veeboerdery 'n groter impak op die toestand van weiveld sal hê as ander boerderytipes, omdat veedigtheid en gevolglik herbivoor-impak gewoonlik veel hoër is as met die ander twee boerderytipes. Onlangse nie-ekwilibria-teorië voer egter aan dat plantedinamika in ariede gebiede gedryf word deur seldsame en buitengewone reënvalgebeure. Biotiese faktore, soos weiding en herbivoor diversiteit sal na verwagting min effek hê op die toestand van weiveld. Hieruit volg die voorspelling dat herbivoorimpak op ariede ekosisteme nie afhanklik is van digtheid nie, en dat hoë veedigtheid algemeen aangeteken vir gemeenskaplike boerderye, nie rede sal wees vir groter ver1iese in weiveld nie. Ariede en semi-ariede weivelde word gekenmerk deur 'n hoë ruimtelike en tydelike veranderinge in plant- en grondparameters. Gevolglik is dit moeilik om te onderskei tussen die effekte van weidingsbestuur en natuur1ike veranderings wat veroorsaak word deur nie-biotiese faktore, soos reënval. Dié probleem kan oorbrug word deur gradiënte van weidingsintensiteit, wat vanaf waterpunte uitstraal, te ondersoek. Vervolgens het ek binne al drie bg. boerderybestuursisteme veranderinge in plant- en grondparameters langs SOOm-lange weidingsgradiënte ondersoek op plase in die semiariede Noord-Kaap provinsie van Suid-Afrika. Plantegroei-analise het getoon dat 'n weidingsgradiënt rondom waterpunte voorkom. Twee kenmerkende sones is in ander studies geïdentifiseer, nl., 'n opofferingsone (waar amper alle plantegroei naby waterpunte uitgetrap is) en die digte, struik-sone (distaal to die opofferingsone). Gemeenskapsveeboerdery het 'n groter negatiewe effek op plaasgewasse as die ander twee boerderytipes, veral waar dit betrekking het op grasspesie-diversiteit, persentasie grond sonder plantbedekking en struikdigtheid. Binne 100m vanaf waterpunte, is grondkwaliteit merkbaar negatief geaffekteer deur kommersiële veeboerdery. Daarteenoor, was daar geen merkbare effek op die grondkwaliteit naby waterpunte van die ander twee boerderytipes nie. Aanvullingsvoer kan moontlik die rede wees vir die waargenome, groter impak van kommersiële veeboerdery op grondkwaliteit. Die resultate van die studie strook met voorspellings van die ekwilibria-teorie van plante-dinamika, daarin dat weidingsimpak digtheidsafhanklik is in hierdie semiariede plaasgebiede. Die resultate toon ook egter, dat voedingsaanvullings die ruimtelike en tydelike verspreiding van vee in so 'n wyse verander, dat dit moontlik 'n veel groter negatiewe uitwerking op grondkwaliteit het as veedighteid per se.

Thesis (PhD (Agronomy))--University of Stellenbosch, 2006. / Vegetation dynamics and restoration strategies of degraded rangeland were investigated near a watering point in the Allaidege communal grazing area in Administrative Zone 3 of the Afar Region in the northeastern lowlands of Ethiopia. The degradation gradient formed by grazing pressure in the study area was stratified into four different areas based on the vegetation cover; severely degraded (SD), moderately to severely degraded (MSD), moderately degraded (MD) and lightly degraded (LD) areas. The study was initiated at the start of the rainy season in June 2003 and lasted untill December 2004. The objectives were to study the effects of the grazing pressure on plant species composition; on plant biomass production and basal cover; on rangeland forage quality; on the rangeland soil status and to determine and quantify viable restoration strategies for forage species in severely degraded rangelands. The botanical composition of the different degradation areas was determined by making a 250 point wheel point method survey in each of four 30 m x 30 m quadrats in each degradation area using the nearest plant approach. The botanical composition of each degradation area was determined by measuring the frequency of occurrence of the different life forms (perennial grasses, annual grasses and forbs) of the species recorded in the field. Accordingly, a significant interaction was observed in both seasons between the different degradation areas and life forms considered. A high abundance of annual grasses was evident in SD and MSD areas in both seasons. In the MD and LD areas, a three-fold increase in frequency was recorded for perennial grasses compared to the MSD area in 2003. In 2004, the frequency of annual grasses, forbs and perennial grasses in the MD area was almost similar to that of the LD area. The abundance of perennial grasses in the MD and LD areas was two- and five-fold higher compared to perennial grasses in the MSD and SD areas respectively. Biomass production was recorded by cutting the vegetation in 1 m x 1 m quadrats in each grazing area at ground level. The dry matter content of subsamples was determined in order to calculate the dry matter production of the quadrat. The differences in dry matter yield recorded in the different degraded areas was not significant for the 2003 season, although an increasing trend in yield was observed from the SD to MD areas. Significant yield differences were however recorded when one outlier in the data was excluded from the analysis. The significant differences occurred between the MD and SD areas where the MD area produced 2.4 t ha-1 more dry matter than the SD area. Similarly, in 2004 no significant yield difference was observed between the degradation areas. However, the contribution of different species to dry matter yield varied in the different degradation areas. Setaria verticillata, Sporobolus ioclados and Paspalidium desertorum were found to be the major species contributing to the dry matter producion in the SD area, S. verticillata and P. desertorum in the MSD area, Chrysopogon plumulosus and P. desertorum in the MD area and C. plumulosus and Panicum coloratum in the LD area. The percentage basal cover was calculated from the number of basal strikes recorded at 1 000 points in each plot of each degradation area using the wheel point method. The total basal cover percentage did not significantly change along the degradation gradient in any of the seasons. However, data for both seasons showed an increasing trend of total basal cover percentage closer to the watering point compared to areas further away from the watering point, except for the SD area, which had the lowest basal cover percentage. The contribution to percentage basal cover by some species decreased while it increased for some other species in grazing areas near the watering point. Forage quality was investigated by analysing sub-samples of the forage samples taken to determine biomass production. The forage samples were analysed for neutral detergent fibre (NDF), acid detergent fibre (ADF), crude protein (CP), lignin, in vitro dry matter digestibility (IVDMD), phosphorus (P), and calcium (Ca) content. The forage showed a decrease in NDF and ADF content in areas close to the watering point in both seasons. This decrease in fibre content was accompanied by an increase in CP content close to the watering point. The increase in CP was significant for the SD area in both seasons. Although a similar trend was observed in both seasons, the CP content was found to be significantly higher in 2004 than in 2003. The results of the lignin analysis were inconclusive if the data of both seasons are considered. It does appear however as if the lignin content of the forage was generally higher in 2003. The 2 years pooled average of P content of the forages showed insignificant variation along the degradation gradient. However, an increase in P concentration of the forages was evident in areas far from the watering point. Contrary to this, Ca concentration was significantly higher in the SD area compared to areas further away from the watering point. Hand clipped forage samples and esophageal collected forage samples were analysed to compare the quality of the samples. Due to the fact that only two animals were available for esophageal collection, differences were in most cases not significant at the 5% level, but trends indicate that animals select higher quality forage than what is assumed based on hand clipping. Organic carbon (OC) content, total nitrogen (N) content, available phosphorus (P) content, available potassium (K) content, exchangeable calcium (Ca) and magnesium (Mg) contents, cation exchange capacity (CEC), total exchangeable bases (TEB), exchangeable sodium percentage (ESP), soil acidity (pH) and base saturation of soils in the different degradation areas were determined by means of acknowledged laboratory methods. No significant differences in OC, N, P, K, Ca, Mg and K content of soil in the different degradation areas could be observed. There was however an increasing trend for OC and N content with distance from the watering point. Sodium concentration and pH increased significantly in areas close to the watering point. Cation exchange capacity content of the soil was variable and no clear trend could be established. Significantly higher TEB and ESP contents were observed in the SD area. In general, the differences in plant biomass production and basal cover, botanical composition, forage quality and soil status over the degradation gradient clearly implicates the negative impact of unrestricted grazing pressure on the rangeland around the watering points. In the rangeland restoration trial, establishment of three local and three exotic grass species in the SD area was investigated. Treatments applied included application of inorganic fertilizer, dry dung organic manure and grass mulch. The mulch treatments caused a significant yield increase for all the sown species. Among all the species, Ischaemum afrum and Tragus berteronianus performed better and produced significantly higher dry matter yields than Enteropogon rupestris, Chloris gayana and Panicum coloratum. In general the study indicated the importance of mulching when planning to restore degraded rangeland under arid environmental conditions.

<p>This thesis presents the study and the design analysis of apermanent magnet synchronous motor (PMSM) for the tractionapplication of an electric vehicle. An existing inductiontraction motor for an electric forklift benchmarks the expectedperformances of the proposed PMSM design. Further, thepossibility of using the identical stator as the one used inthe induction motor is explored for the fast prototyping. Theprototype motor is expected to be field-weakened and to have aconstant power speed range (CPSR) of 2.5 to 3.</p><p>A design approach based on the CPSR contour plot in aninterior permanent magnet (IPM) parameter plane is derived toobtain the possible designs that meet all the designspecifications and the targeted CPSR. This study provides thepossible alternative designs for the subsequent futureprototype motors.</p><p>An analytical approach to estimate the iron loss in PMsynchronous machines is developed and included in the designprocedure. The proposed technique is based on predicting theflux density waveforms in the various regions of the machine.The model can be applied at any specified load condition,including the field-weakening operation region. This model canbe ultimately embedded in the design process for a routine usein loss estimations.</p><p>The first prototype motor with an inset permanent magnetrotor has been built and the available measurements are used tovalidate the design performance. In particular, the thermalanalyses based both on the lumped-circuit approach and thenumerical method are compared with the measured results. Asecond and possibly a third prototype motor targeting a widerand higher performance will be carried out in the continuingphase of the project.</p><p><b>Keywords:</b>Constant Power Speed Range, Electric Vehicles,Field-weakening, Reference Flux Linkage, Iron Loss, PermanentMagnet Synchronous Motor, Thermal Analysis</p>

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Amphibian populations are declining on a global scale and although disease outbreaks are a commonly accepted hypothesis they are not the only one. My aims for my thesis were to study the home range of Leiopelma hamiltoni, to determine whether a photographic database could be used to individual identified them and monitor the health status of the population. Habitat loss is a possible cause. For this reason monitoring an animals' home range is a possible method to detect early impacts the population is facing. By tracking 12 L. hamiltoni within a 12 m x 6 m grid on Maud Island, it was shown that the home range size can vary from 0.5 m2 to 25 m2 based on the minimum convex polygon method. However, to track multiple individuals it is important to be able to distinguish among frogs. The commonly used methods of identification, such as toe clipping, pose potentially detrimental effects. Therefore, non-invasive methods based on natural markings need to be established. Through the use of the dark pigmented patterns found on the skin of L. hamiltoni individuals can be identified on recapture with a mean accuracy of 93%. By developing a database to maintain the photographs used for individual identification, the database can also be used to monitor the status of the population. During 2003 numerous L. hamiltoni were observed with denuded patches predominantly on the facial region. By monitoring five individuals within the captive facility at the University of Canterbury it was discovered that frogs appear to be able to cure themselves. Through researching the home range requirements and developing a photographic database to monitor the population status of L. hamiltoni, it will aid in the management of ensuring the long-term survival of this archaic species of frog.