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  • 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.
31

An evaluation of strategies for hedging feeder cattle in the Pacific Northwest

Gatti, Andrew Leo 12 October 1984 (has links)
Over the past decade, feeder cattle backgrounders in the Pacific Northwest have been subject to sharp price fluctuations for their output. The result has been variable profits and losses. This situation creates a need for management and marketing techniques which can provide Pacific Northwest cattle ranchers with protection against price risks while enhancing the profitability of their operations. Recent economic literature has shown hedging with futures contracts to be an effective tool for mitigating risk and/or increasing the net revenues of cattle producers in a number of regions of the United States. The objective of this research was to determine whether hedging with futures contracts could have increased the profitability of Pacific Northwest feeder cattle production while decreasing the effects of price volatiliy. To realize this objective, the economic performance of alternative hedging strategies were evaluated for several methods of feeder cattle backgrounding indigenous to the Pacific Northwest region. Four hedging strategies -- routine, moving average, profit objective, and triangular probability distribution — were evaluated for hedging the output of four simulated production systems. The mean and standard deviation of annual net returns were computed for each hedging strategy to serve as measures of profitability and risk, respectively. The results of not hedging were also obtained to provide a basis for comparing alternative hedging programs. Sample t and F tests were conducted to determine whether there were statistically significant differences between the means and standard deviations of the unhedged and hedged positions. Dominant hedging strategies were then identified for each production system. Based on the results of the mean-variance analysis, it appears that the use of selective futures market hedging strategies would have provided greater and more stable levels of profit compared to the net incomes obtained without hedging. Sample t and F tests, using 80 and 90 percent levels of significance respectively, showed that hedging could have significantly decreased the variability of the producer's flow of income without significantly changing the operation's average profitability. Moving average, profit objective, and triangular probability distribution strategies were dominant, increased average profitability, and significantly lowered risk for at least one production system each. Overall, moving average strategies generated the highest mean profits with the greatest risk. Profit objective strategies generally resulted in lower mean profit than moving average strategies but with less risk. The risks and returns from hedging with triangular probability distribution strategies were usually between the moving average and profit objective procedures. Strategies which performed well in this study should also perform well in the future if conditions in the feeder cattle markets do not vary substantially from those of the previous decade. Thus, hedging with futures market contracts may provide the Pacific Northwest feeder cattle producers with protection against price risk and enhanced profitability. / Graduation date: 1985
32

The linear and non-linear baroclinic instability in the eastern North Pacific

Lee, Dong-kyu 04 May 1987 (has links)
Using a linear quasi-geostrophic model of large scale spiraling flow and vertical density gradient in the eastern North Pacific, we evaluate the complex dispersion relationships for quasi-geostrophic waves. Our calculations indicate that the geostrophic circulation of the eastern North Pacific can locally convert potential energy to mesoscale kinetic energy on a scale comparable to the observed space and time scale and should be a source of eddy energy, distant from the eddies spawned by the Kuroshio and near the topographic features. But the local growth rates by linear stability analysis do not relate to the observed features of eddy kinetic energy in the eastern ocean; eddy kinetic energy increases to the south and has a maximum in the subtropical region. The non-linear baroclinic instability is analyzed using a three-layer quasi-geostrophic numerical model. Three experiments with different idealized initial mean flow are performed. Local energetics are calculated to highlight the difference between the southward return flow and westward return flow regions. It is found that the boundary flux of mean to eddy kinetic energy conversion is the main differences between two regions: it is large in the westward return flow region but is small in the southward return flow region. Two waves with different characteristics are found: the short waves (periods of 120 days), that propagate to the west and form several wave trains parallel to the southern boundary, and the long waves (periods of 200 days), that propagate to the south-west. These two waves are remarkably similar to the measurements of open ocean eddies at 28°N and 152°W. It is shown that there are high eddy activities in the southward return flow regions by influxes of eddies from other areas, but the southward return flow region is vacant in eddies by outflows of the westward and south-westward propagating waves. / Graduation date: 1987
33

The effects of rainfall on temperature and salinity in the surface layer of the equatorial Pacific

Bahr, Frederick L. 19 July 1991 (has links)
Measurements of temperature and salinity in the upper 5 m of the ocean along the equator showed cool fresh anomalies due to rain showers. The measurements were made between 140 W and 110 W during April 1987, an El Nino year. The eastern equatorial Pacific was characterized by weak winds (3 m/s average), high rainfall (1.6 cm/day), and warm surface temperatures (28.4 C). Measurements of temperature were made from a catamaran float at 0.5 and 1 m depth and at 5 m depth from the ship. Salinity was measured at a depth of 1 m from the float and 5 m from the ship. The float was towed off of the port side of the ship outside of the bow wake. Near-surface low temperature and low salinity anomalies due to cool rainfall were encountered. These anomalies were on average cool and fresh by 0.02 C and 0.2 PSTJ with maximum values of 0.5 C and 1.6 PSU. The horizontal extent of the anomalies ranged from less than 10 to more than 100 km. Rainfall depths estimated from salt conservation agreed roughly with shipboard rain-gauge measurements. The characteristic lifetime of the anomalies, estimated from the ratio of the average rain depth to average rain rate, was about 10 hrs. Rainfall temperatures were computed from the T-S mixing curves for three large, newly-formed anomalies. The average rainfall temperature was 21 C. Ocean buoyancy fluxes estimated for intense rain showers were an order of magnitude larger than the fluxes in the absence of rain. / Graduation date: 1992 / Best scan available for p.15-16, 35. Original is a black and white photocopy.
34

Elemental distributions in the components of metalliferous sediments from the Bauer and Roggeveen Basins - Nazca Plate

Lopez, Carlos 19 September 1977 (has links)
Major and trace element analyses were made on biogenic carbonate, silica, and fish debris and on authigenic philhipsite, micronodules, and yellow and brown aggregates recovered from Bauer and Roggeveen Basin metalliferous sediments. Phase components and the bulk samples were analyzed by INAA and MS methods. Leachates and residues from ammonium oxalate and mild HC1 leaches of bulk and fine sediment fractions were also analyzed. The mild acid leach removed fish debris and carbonate, and the oxalate leach dissolved the micronodule phase. Sediments of the Bauer and Roggeveen Basins differ in bulk composition, yet respond to various chemical treatments in similar manner. I interpret this as indicative of a close similarity in the mineralogy of these two areas. An iron-rich smectite, manganese micronodules, and fish debris dominate the sediment compositions of both basins. The smectite phase concentrates Fe, Si, and Al. Manganese, Co, Ni, Ce, and W are concentrated in the micronodule phase and Ca, Sc, and the lanthanides predominantly in the fish debris component. The trace elements Cu, Zn, As, and Sb are distributed in a complex manner among the three principal phases. Barium, and some Al and Fe, may be present in small quantities of barite, feldspars, and goethite, respectively. Silica, carbonate, and phillipsite phases exist in. such low concentrations that they do not contribute significantly to the bulk composition of the sediments. The response of the various size fractions leached indicates a uniformity of distribution of sediment components from the coarse to the fine fractions. / Graduation date: 1978
35

Constraining the duration and extent of low temperature alteration in the Pacific Ocean basin

Paul, Heather J. 10 April 2008 (has links)
No description available.
36

Characterization of a spawning pheromone of Pacific herring

Schnorr von Carolsfeld, Joachim 01 June 2017 (has links)
Pacific herring, Clupea harengus pallasi, possesses a pheromone in the milt and testes that triggers spawning behaviour in reproductively mature individuals of both sexes, and plays a role in synchronizing the school spawning that is distinctive of this species. The pheromone was found to be effective as a transient olfactory stimulus in eliciting a behavioural response that varied in the degree of expression and time course. Stimulus strength was found to influence the time course of the response, whereas differences in maturity, evident through examination of plasma levels of steroids, were correlated with a propensity to respond to the pheromone. Input from factors other than the spawning pheromone appear to be needed to elicit prolonged spawning; some of these factors also act through olfaction. Immediate effects of stress were not found to influence the response to the spawning pheromone. Plasma levels of reproductive steroids of herring during the spawning season were measured with radioimmunoassays. Peak levels of 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) were found to coincide with final maturation in females and the initiation of milt production in males, suggesting that this steroid is the maturation-inducing steroid of this species. Other features found to be distinctive of the reproductive physiology of the herring included low plasma levels of the unconjugated maturation-inducing steroid, high levels of 17α-progesterone (17-P) and 3α,17α-dihydroxy-5β-pregnan-20-one (3α,17-P-5β), and high levels of glucuronated steroids. Structural investigation of the pheromone with liquid chromatography/ mass spectrometry showed that it consists of at least two components which do not elicit a behavioural response individually. One of these compounds is sulphated 17,20β-P. The structure of proteinaceous hormones involved in controlling reproduction of the herring was also investigated. It was shown that this species possesses three forms of gonadotropin-releasing hormone (GnRH) in the brain, one with a structure that has not been reported before. These results indicate that the presence of three GnRH forms is a primitive, rather than derived, condition in the teleosts. The structure of the (β-subunit of gonadotropin II (GtH ll-β) of herring was also deduced by isolation of a cDNA for this molecule. The structure of the herring GtH ll-β was found to be quite different from other teleost molecules of this kind, and a phylogenetic analysis of known GtH ll-β structures suggests that the β-subunit of both mammalian gonadotropins may be most closely related to the β-subunit of teleost GtH-l. / Graduate
37

Investigation of the Miocene Moki Formation within the Parahaki 3D Survey; Taranaki Basin, Offshore New Zealand Using Some Geophysical Tools

Alekhue, Jude E. 11 April 2019 (has links)
<p>Abstract A geophysical analysis was carried out to delineate and characterize the Mid-Miocene Moki sandstone reservoir in the Taranaki basin, offshore New Zealand. The study is an effort to use the new 3D seismic from the Parahaki survey to answer some concerns of an earlier 2D seismic line that drilled a dry hole. Well log curves were used to identify two sands within the Moki package (Moki-1 and Moki-2). Amplitude Variation with Offset (AVO) forward modeling was done to evaluate the seismic response of the Moki-1 and Moki-2 sands. The modeling results indicate that the Moki-1 sand exhibits a Class III AVO response, while the result of the Moki-2 show a class 2/2P AVO response. The Far times Far minus Near (Far*(Far- Near) AVO attribute was employed to discriminate hydrocarbon from the background geology. This attribute was applied because gathers were available only over a subset of the survey and not the entire survey area. Intercept/gradient crossplot of gathers close to the well location falls in quadrant IV and shows a wet sandstone background trend, which is consistent with the modeled response. The results from the analysis underscore the application of fluid substitution and AVO synthetic modeling in reservoir seismic studies.
38

Zoogeography and systematics of cephalopods of the northeastern Pacific Ocean

Jefferts, Katharine 23 November 1982 (has links)
Graduation date: 1983
39

Calcium in the equatorial Pacific Ocean

Olson, Eric J. 07 December 1981 (has links)
Graduation date: 1982
40

The subsurface frontal zone beneath the subtropical convergence in the northeast Pacific Ocean

Blanton, J. O. 25 January 1968 (has links)
Graduation date: 1968

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