• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2107
  • 1590
  • 909
  • 860
  • 310
  • 214
  • 212
  • 153
  • 153
  • 153
  • 153
  • 153
  • 148
  • 147
  • 65
  • Tagged with
  • 7524
  • 1499
  • 1369
  • 1329
  • 1328
  • 913
  • 882
  • 734
  • 727
  • 724
  • 724
  • 623
  • 446
  • 445
  • 401
  • 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.
341

An infrared and millimeter-wave spectroscopic study of the DR21 outflow

Garden, Rognvald Peebles January 1987 (has links)
In this thesis, new high-angular resolution infrared and millimeter-wave spectroscopic observations of the enigmatic outflow activity associated with the luminous DR21 star-form ing region are presented and discussed. The intent is to use these observations to undertake a detailed investigation of the physical nature of the central driving engine and the related dynamical processes involved in collimating the hypersonic outflow gas. In the infrared, large-scale mapping and high-spectral resolution profile measurements of the vibrational H2 v = l-0 S(l) line are used to investigate the morphology and kinematic structure of the hot, dense gas that is collisionally excited behind fast shocks. The H2 emission delineates a highly-collimated pair of bipolar jets that extend over a projected distance of ~ 5 pc, centred on the DR21 molecular cloud core; this is undoubtedly the most luminous (in H2 line emission) and extended galactic outflow source yet discovered. Furthermore, the H2 line profiles at certain locations within the jets possess high-velocity wings that extend to beyond 100 km s-1 from the DR21 rest velocity. These observations pose interesting dynamical consequencies as at such high velocities H 2 should be entirely dissociated. In an attempt to derive the mass distribution and velocity structure of the molecular gas participating in the outflow, and hence the driving force and associated mechanical luminosity, detailed observations were also undertaken at millimeter-wavelengths in the CO J= 1 -0 and CS J = l-0 , J= 2-l lines. It is found that the DR21 outflow is considerably more massive and energetic than any other outflow source studied to date. Another feature unique to the DR21 region is the discovery of extended high-velocity CS emission that is dynamically associated with the outflow lobes and extends to a distance of ~ 3 pc from the cloud core; this component presumably originates from am bient gas that has been swept up and compressed by the outflow. The high-velocity CS may be overabundant by 2 orders of magnitude, in good agreement with current numerical models of post-shock chemistry. The CS observations further reveal the existence of an extremely massive, slowly rotating disc of high-density neutral gas that surrounds the central outflow source. It is most probable that the large momentum flux in outflow material derives from efficient mass-loss from the surface of this disc, mediated via a centrifugally propelled, magneto-hydrodynamic wind. An additional confinment mechanism is required to collimate the outflow at large distances from the flow origin. If this confinment is primarily pressure driven, then sudden changes in the ambient cloud pressure could induce a succession of oblique shocks within the outflow that may give rise to the periodic clumpy structure that characterizes the H2 emission-line jets. Other consequencies of the pressure-confinment mechanism are discussed and a broad resemblance to extragalactic radio jets is remarked upon.
342

Dopad dotačních příjmů na rozvoj zemědělství v Jihočeském kraji / The Impact of Subsidy on the Development of Agriculture in the South Bohemian Region

VACUŠKOVÁ, Milada January 2008 (has links)
The aim of the thesis was to examine the impact of subsidy on the development of agriculture in the South Bohemian region. The first part was focused on the development of the agrarian policy in the Czech republic and on the characteristics of the subsidiary titels, as a step in the common agrarian policy of the EU. The other part of the thesis dealt with the characteristics of the South Bohemian region and its agriculture and with the analysis of the subsidy utilised by agrarian contractors in the South Bohemian region. The analysis concerned the using of subsidy from the direct payment, the horizontal plan of the rural development and the operational programme {\clqq}The Rural Development and Multifunctional Agriculture`` within the period 2004{--}2006. On the basis of the analysis it was possible to consider the impact of individual subsidy on the receipts in agriculture. According to the acquired data and the current Czech and Bavarian subsidiary policy a proposal of the direction of the future subsidiary policy has been draft.
343

Geology of the Mount Brenner stock near Dawson City, Yukon Territory

Lambert, Maurice Bernard January 1966 (has links)
The Mount Brenner stock has intruded folded sedimentary and meta sedimentary rock that lie 40 miles northeast of Dawson City, Yukon Territory. The stock consists of four major concentric zones: (l) an outer zone of fine to medium-grained augite-biotite monzonite; (2) a zone of very coarse-grained monzonite porphyry; (3) an intermediate zone of porphyritic horn blende monzonite; and (4) a central zone of coarse-grained pink quartz monzonite porphyry. Except for the outer zone, all rock types are porphyritic and the alignment of feldspar phenocrysts gives the rocks a primary flow structure which conforms to steeply outward dipping gradational internal contacts. All external contacts are sharp. The regional structural trend is modified in the vicinity of the stock so that beds are generally conformable with the intrusive contact. From structural evidence, it is concluded that at the present level of erosion, the stock was emplaced by forceful injection. The different rock zones of the stock can be accounted for by differentiation of an augite-biotite monzonite magma by a combination of crystal fractionation , volatile and alkali diffusion, and multiple intrusion. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
344

Study of apple yield relationships in 1969 in the Okanagan area of British Columbia

Lee, Ewon January 1972 (has links)
The purpose of the study is to determine which factors contributed to the production of apples in the Okanagan area during the year 1969. Regression analysis is used in an attempt to quantify yield relationships. A comparison is made among different tree-size categories in order to determine whether it is necessary to fit separate regression equations instead of using the data for the three groups in a single regression equation. For this purpose an Equality of Slope Test is performed. The outcome of the test shows that there are no significant differences among corresponding coefficients in the equations for tree-size categories. Hence it is feasible to combine them into one equation. For the regression analysis, two different types of yield relationships are employed: one is a Cobb-Douglas function linear in the logarithms and the other is a quadratic function. Both functions include a dependent variable, namely, yield per acre and seven independent variables; that is, density, age, value of fertilizer applied, value of spray applied, pruning and thinning labour hours, geographical dummy, and tree-size index. These independent variables are measured on a per-acre basis except in the case of age, geographical dummy and tree-size index. The data, which consists of cross-section informa- tion for 1969 represents one hundred and nineteen sample apple plots. It was derived from personal interviews with apple growers. The quadratic function poses a problem arising from cross-terms in the equation. It was necessary to modify the function in such a manner that the cross-terms included in the regression equation were justified on biological or economic grounds. The regression results for each type of function used in the analysis are discussed and estimates of coefficients and related standard errors shown. It seems desirable that data should be broken down into apple variety groups because different varieties of apple may well have distinct bearing characteristics. Apple trees in the specific plots under study, however, are made up of a mixture of varieties, thus it is extremely difficult to draw a clear map of acreages occupied by each variety. In attempting to obtain variety data, notwithstanding the mixture of varieties in stands, the original data is broken down under certain assumptions. Also in decomposing apple yields into grade constituents similar problems arise. Despite these difficulties, tests of differences among average yields are made under stated conditions for varietal, tree-size, apple-grade, and regional categories. These tests reveal that there are no significant differences in average apple yields for varieties, apple grades and regions., but there are significant differences in the case of different tree sizes. The results of these Tests are presented in Chapter VI. The quadratic form of function seems, within the theoretical framework, to be able to represent satisfactorily the apple yield relationship with the selected independent variables. But, in practice, it does not conform well to the empirical situation; it produces a serious multicolline-arity problem from the point of view of statistical inference. The Cobb-Douglas function, however, does not cause such a problem. Apart from this, its application brought in almost all the coefficients corresponding to the basic independent variables except for the coefficient of the tree-size index variable. On this evidence, a tentative conclusion was made in favour of the Cobb-Douglas function for the representation of an apple yield relationship in the Okanagan in 1969. / Land and Food Systems, Faculty of / Graduate
345

The influences of the Holy Sepulchre on architecture in the Mediterranean basin from the fourth to the end of the seventh centuries

Schutt, Karl Robert January 1970 (has links)
The Holy Sepulchre in Jerusalem was built by Constantine from 327 to 335. It consisted of a basilica, the Martyrion, and a small edicula over the tomb of Christ, known as the Tegurium. By the end of the fourth century a Rotunda was built over the edicula. This complex was quite unique in Christian architecture from the fourth to the end of seventh centuries but this paper reveals that it was not a popular architectural group to serve as a model for other churches in the Mediterranean basin. Only one building, the Cathedral of Ravenna, built by Ursian and dedicated to the "Resurrection", can be termed a "copy", and it only duplicated certain architectural features from the Martyrion, while the Rotunda was completely ignored. Only three buildings, all rotundas, seemed to have been derived from the Anastasis Rotunda; S. Stefano Rotondo in Rome, SS, Karpos and Polykarpos in Constantinople and the moslem Dome of the Rock in Jerusalem. Although Medieval copies of this building were octagonal in plan, no octagonal copies of the Rotunda were constructed before the moslem invasions in the seventh century. No architectural reproductions of the Tegurium are known but the building may have served as a model for reliquaries. The ninth century complex of S. Stefano (San Sepolcro) in Bologna duplicated the group of buildings at the Holy Sepulchre and, although a number of fifth to eighth century church complexes have buildings grouped in a similar fashion, no copies from the Byzantine period are known. Buildings on the site of Christ's tomb were examined in turn by studying illustrations and descriptions of them. Churches throughout the Mediterranean basin were then compared to the restorations of the buildings in Jerusalem to determine if there were any resemblances. If a building only duplicated a number of architectural features or the dedication from the Holy Sepulchre it was considered to be a derivative. To be a copy, both features had to be evident in the secondary structure. / Arts, Faculty of / Art History, Visual Art and Theory, Department of / Graduate
346

Cestovní ruch jako faktor rozvoje na Českolipsku / Tourism as a Factor of Development in the Českolipsko Region

Rímská, Laura January 2008 (has links)
Tato práce charakterizuje cestovní ruch a jeho formy z hlediska jeho dopadu na hospodářský vývoj regionu. Zabývá se vývojem cestovního ruchu v České republice po roce 1989, dále hodnotí region Česká Lípa z hlediska polohy a jejího vlivu na rozvoj cestovního ruchu v regionu a obyvatelstva z demografického hlediska. Zaměřuje se i na vliv dopravní infrastruktury a přírodních podmínek na cestovní ruch. Soustřeďuje se na zdroje cestovního ruchu jako turistické zajímavosti, kulturní i přírodní památky a na hlavní centra a oblasti cestovního ruchu z hlediska atraktivity území. Dále práce analyzuje turistickou infrastrukturu jako ubytování a informační centra, možnosti rozvoje cestovního ruchu v regionu a vliv cestovního ruchu na rozvoj regionu. Předmětem analýzy jsou také způsoby propagace regionu. Závěrem práce hodnotí využití stávajícího potenciálu regionu, přínos cestovního ruchu i to, jak ovlivňuje rozvoj daného území. Navrhuje v tomto ohledu způsoby zlepšení a možnosti budoucího vývoje.
347

Rozvoj cestovního ruchu v Plzeňském kraji: případová studie marketingové strategie turistického regionu Šumava / Development of tourism in Pilsen region: case strategy of marketing strategy of tourist region Šumava

Zippererová, Iva January 2013 (has links)
The aim of this thesis is suggesting marketing strategy of tourist region Šumava. The theoretical part is focused on elaboration theory related to the tourism. There are defined the basic terms and there is also evaluated position of tourism in regional development and national and world economy as well. In the practical part there is defined region the thesis is about and then there is subjected to comparison attendance of Pilsen region, South Bohemian region and touristic region Šumava towards other regions of the Czech republic. In the end of the practical part there is thanks to marketing mix prepared the marketing strategy of touristic region Šumava, which is the aim of this thesis.
348

Structural relations of the southern Quesnel Lake gneiss, Isosceles mountain area, southwest Cariboo mountains, British Columbia

Montgomery, John R. January 1985 (has links)
The southern extension of the Quesnel Lake Gneiss lies approximately 10 km northeast of the Intermontane-Omineca Belt tectonic contact in the southwestern Cariboo Mountains, British Columbia. The aim of this thesis is the investigation of the structural development and style at a deep structural level relative to the 1MB-OB contact, and to determine the nature origin of the southern extension of the Quesnel Lake Gneiss. Omineca Belt rocks in the Quesnel Lake region are the Late Proterozoic to Late Paleozoic Snowshoe Group metasediments. The Snowshoe Group rocks in this study area comprise a package of variably micaceous schist, quartz-biotite gneissose schist, calcareous metasandstone, marble and amphibolite which represent deformed and metamorphosed continental margin deposits. The Quesnel Lake Gneiss is a predominately subalkaline granodioritic intrusive into these sediments that has been modified by subsequent deformation and metamorphism. High Sr content, low initial ⁸⁷Sr/⁸⁶Sr ratios and an alkalic component imply a mantle source although possible Pb inheritance in zircons and regional Sr data suggest a certain amount of assimilated continental crust A U-Pb zircon age on the Quesnel Lake Gneiss indicates intrusion in Mid-Paleozoic, probably Devonc—Mississippian time. A regional metamorphic event affecting the entire sedimentary and intrusive package is interpreted to have occurred in the Middle-Jurassic as suggested by sphene U-Pb geochronometry and regional stratigraphic relations. The structural sequence observed in this area is composed of five phases of folding followed by a brittle fracturing and faulting phase. The entire sequence of deformation is seen in both the Snowshoe Group and the Quesnel Lake Gneiss. A pervasive metamorphic foliation defines the compositional layering (S0/1) and is axial planar to isoclinal first phase folds in both rock packages. Syn-metamorphic second phase deformation is evidenced as tight similar-style folds with an axial surface penetratively developed at a low angle (10-15°) to the compositional layering. Syn- to post-metamorphic third phase deformation produced southwest verging folds with only locally penetrative axial surfaces developed at approximately 40° to SO/1 compositional layering and northwest plunging fold axes nearly coaxial with F2 folds. The Quesnel Lake Gneiss shows a lack of F3 macroscopic folds. Fourth and fifth phase folds are brittle, broad warps that are only locally developed in the more micaceous units. A series of ť vs. α plots on second and third phase folds in both rock types indicates a ductile regime associated with high shear strain during F2 deformation with decreasing shear strain and less ductile behavior during the third phase of deformation. This change in behavior corresponds with the waning of metamorphism. At least one regional metamorphic episode has affected this area in association with the deformational sequence outlined above. The metamorphic peak occurs post-F2 and pre- to syn-F3 deformation producing Barrovian-type assemblages of the amphibolite facies. Metamorphic temperatures of approximately 590° C at 5.5 kb were determined by garnet-biotite geothermometry in sillimanite-bearing schists northeast of the Quesnel Lake Gneiss. A tectonic history for the rocks in this map area began with the deposition of the Snowshoe Group sediments in a continent margin basin from the Late Proterozoic to the Early Mississippian. Intrusion into this package by the Quesnel Lake granitic body occurred between 317 and 400 Ma ago. The first phase of deformation recognized in the Snowshoe Group and Quesnel Lake Gneiss is absent in the Quesnellia and Slide Mountain rocks and may also be of Paleozoic age. The accretion of Quesnellia onto the continental margin in Early Jurassic time is inferred to have initiated the subsequent deformation and regional metamorphism. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
349

Geology of the Three Ladies Mountain/Mount Stevenson area, Quesnel Highland, British Columbia

Getsinger, Jennifer Suzanne January 1985 (has links)
In late Proterozoic to early Paleozoic time, continent-derived clastic sediment and minor carbonate of the Snowshoe Group were deposited in a continental slope to shelf environment, and shallow marine elastics and carbonates of the Cariboo Group were deposited nearer to the shore of North America. The Snowshoe Group is divided into a lower sequence of micaceous quartzite, pelite, and minor amphibolite, all interlayered with quartz diorite sheets; and an upper sequence of micaceous quartzite, pelite, and carbonate with minor calc-silicate and amphibolitic rocks. Early isoclinal (F1A) and NE-verging tight folds (F1B) formed together with a metamorphic foliation. Tight to normal, cylindroidal second phase (F2) folds, characterized by SW-vergence and NW plunge, formed during the mid-Jurassic Columbian orogeny at about the same time as accretion of suspect terranes southwest of the map area. Prograde metamorphism in the Barrovian series of amphibolite facies was synkinematic to postkinematic to F2 folding, with maximum metamorphic recrystallization outlasting deformation. Garnet-biotite geothermometry indicates temperatures of 525 ± 20°C for pelites near the kyanite to sillimanite zone isograd. Garnet-aluminosilicate-ilmenite geobarometry limits P to less than 7 kb. Grossular-anorthite-aluminosi1icate geobarometry gives P = 5.5 ± 0.7 kb. Retrograde metamorphism and F3 kink-folding occurred during uplift, followed by broad warping (F4) with NE trend. The low-angle, postmetamorphic Little River Fault emplaced chlorite to biotite zone phyllite and carbonate of the Cariboo Group, in the hanging wall, against staurolite-kyanite to sillimanite schists and gneisses of the Snowshoe Group, in the footwall, with latest movement of the hanging wall in an ESE direction. A Rb-Sr model depositional age of approximately 750 Ma, assuming an initial ⁸⁷Sr/⁸⁶Sr ratio of 0.708, was obtained for Snowshoe Group metasedimentary rocks. Paleozoic plutonism is indicated by a Rb-Sr whole-rock isochron date of 530 ± 94 Ma with initial ⁸⁷Sr/⁸⁶Sr ratio of 0.706, and U-Pb dates on zircon, indicating a minimum age of 335 Ma and maximum age of about 450 Ma, for quartz dioritic gneiss intrusive into the Snowshoe Group early in its deformational history, pre-F1B folding. Late- to post-metamorphic pegmatite cooled through 400-500°C at 86 ± 3 Ma. The age of the Little River Fault is bracketed between intrusion of pegmatite and a Miocene(?) erosion surface. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
350

Geology of the Harper Ranch Group (Carboniferous-Permian) and Nicola Group (upper Triassic) northeast of Kamloops, British Columbia

Smith, Randall Blain January 1979 (has links)
The "Cache Creek Group" as previously mapped in the Kamloops area actually consists of two sequences of different ages, the Late Paleozoic Harper Ranch Group (new name), and the Upper Triassic Nicola Group. The lower part of the Harper Ranch Group is a 5 km-thick sequence of hemipelagic mudstone and redeposited tuff with rare lenses of shallow marine limestone which yield fossils of Late Mississippian to Middle Pennsylvanian age. This sequence is disconformably overlain by several hundred metres of Lower Permian limestone forming the upper part of the group. Only the lower 2.3 km of the section were studied in detail. In this portion, andesitic to dacitic tuffs consist of ash produced by shallow marine eruptions, then reworked and redeposited in deep water by turbidity currents and high concentration subaqueous flows. A thin Upper Mississippian bioclastic limestone with a diverse marine fauna is found near the base of the sequence. It accumulated during a period of volcanic quiescence and shallowing of the basin floor. The Harper Ranch and Chilliwack Groups were probably parts of a Late Paleozoic volcanic arc which formed above an east-dipping subduction zone. East of the arc was an "oceanic" back-arc basin bounded on the east by orogenic lands formed by the Late Devonian to Mississippian Caribooan orogeny. This orogenic terrane supplied the lithic-rich elastics of the Late Paleozoic Anarchist Group, Mt. Roberts Formation, and the Eastern assemblage of Monger (1977). Pre-Late Triassic deformation and low grade metamorphism of the Late Paleozoic eugeoclinal rocks of southern British Columbia may have been caused by Permo-Triassic closure of the back-arc basin, and collision of the arc with the old orogenic terrane to the east. A new volcanic arc formed in the Late Triassic is represented by volcanic flows and breccias of the Nicola Group west of Kamloops. East of Kamloops, the Nicola Group consists of 3 km of sediments and volcaniclastics which accumulated in deep water within a back-arc basin. Pelagic and hemi-pelagic mudstones dominate the section, but are interbedded with redeposited tuff, lithic sandstone and conglomerate, and limestone, all of which were deposited by turbidity currents and high concentration density flows. Massive and pillowed basaltic or andesitic volcanic flows occur near the base and top of the sequence, which has been subdivided into five lithologic units. Conodonts extracted from limestones yield Karnian ages. Redeposited tuffs in the Nicola Group were probably derived from the volcanic arc to the west, and also from submarine volcanoes in the basin to the east. Lithic sandstones and conglomerates contain sedimentary and volcanic detritus, including abundant chert and cherty mudstone. These may have been derived from accreted oceanic rocks of the Cache Creek Group, exposed in the emergent Pinchi geanticline west of the volcanic arc. Detrital blue amphiboles in fine-grained turbidite limestones suggest this sediment was also derived from shallow waters surrounding the Pinchi terrane. The Nicola volcanic arc therefore seems to have been built on an east-facing paleoslope. The back-arc basin was floored by older eugeoclinal rocks, and stretched from the arc eastward to the miogeocline. The Harper Ranch and Nicola Groups are separated by a northwest-trending vertical fault, probably of Late Mesozoic or Early Tertiary age. East of the fault the lower Harper Ranch Group forms an east-facing homocline with few discernible mesoscopic folds. To the west, lithic units in the Nicola Group outline a pair of faulted northwest-trending folds: an upright syncline on the east, and a westward-overturned anticline on the west. Deformation probably took place during the Latest Triassic to Earliest Jurassic Inklinian orogeny. The Triassic rocks are intruded by the Paul Peak Stock, a zoned intrusion ranging from pyroxenite to granite in composition. This pluton is similar to zoned Alaskan-type mafic-ultramafic intrusions in composition and tectonic setting, and is probably part of the 200 m.y. plutonic suite of southern British Columbia. Numerous andesitic to rhyolitic dikes of probable Eocene to Oligocene age cut all other rock units. Prehnite-pumpellyite facies metamorphism has affected all rock units in the area, including the dikes. Alteration of volcaniclastic rocks in the Harper Ranch Group is much more complete than in the younger rocks, suggesting that the Paleozoic rocks were affected by the Permo-Triassic low grade metamorphic event recorded elsewhere in southern British Columbia. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Page generated in 0.0999 seconds