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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.
71

Do sales targets put basic psychological needs in the backseat?

Osberg, Jonas January 2013 (has links)
Lack of motivation is a substantial productivity cost for organisations and business in generally work under the assumption that pay predicts performance. Satisfaction of the basic psychological needs has in research demonstrated a positive relationship with a better performance (i.e. Baard et al., 2004). If this is the case in the complex nature of sales work, with its primary focus on goals set (sales target) is yet to be decided. The purpose of this study was to examine the relationships between the basic psychological needs, health and sales performance. The results emanating from this study on 252 sales people goes against previous research on performance as no significant relationships were found between the basic psychological needs and sales performance. However the study provides a strong empirical confirmation of the proposition that the basic psychological needs play an important role for health. Overall the results suggest that goal-setting (i.e. sales target) has significant consequences in shaping salespeople's cognitive aspect of motivation, putting the basic psychological needs behind and may result in impaired health.
72

Commitment in NGOs : A Dual Case Study in Sweden

Liu, Yu, Inkabi, Patience Attakora January 2015 (has links)
Background: A successful organization is the one that recognizes the importance of its human element and take into account their commitment to ensure the attainment of its objectives. However, the focus into the study of commitment among workers is often directed towards for-profit organizations with NGOs receiving less attention. This HRM related issue accord several scholars, is said to be an important factor to be considered in order to ensure a successful organization be it for-profit or NGO. The issue of commitment among workers however tend to take several direction as the result of the multidimensional nature of organizations, hence the varying configurations of commitment mindset (Affective, Normative and Continuance) and the presence of various targets of commitment (e.g. organization, customers etc.) among workers. Aim: The aim of this thesis is to examine the commitment among workers in NGOs, by investigating the various targets of commitment among different categories of workers of NGOs in Sweden. The paper will further investigates whether the targets of commitment among the different categories of workers in NGOs differs and what influences these differences. Through the empirical cases, this thesis will provide appropriate guidance to ensure commitment among categories workers in NGOs and also contribute to previous research with regards to commitment among categories workers in NGOs. Methodology: The qualitative research approach was used in the conducting of this study. A dual case study was undertaken 12 semi-structured interviews with six from each case organization. Participants were drawn from the two main categories of workers in NGOs thus from volunteers and paid workers. Results: The conducted research study reveals there are differences in relations to the targets of commitment among the different categories of workers as well as thedisplay of the different types of commitment towards these targets. The guideline identified by this paper to ensure commitment among workers in NGOs should be a considerable amount of attention to workers development and recognition from the organization.
73

The global network of marine protected areas: developing baselines and identifying priorities

Wood, Louisa Jane 05 1900 (has links)
Recently adopted global marine protection targets aim to protect 10-30% of marine habitats within the next 3 to 5 years. However, these targets were adopted without prior assessment of their attainability. Moreover, our ability to monitor progress towards such targets has been constrained by a lack of robust data on marine protected areas (MPAs). In this thesis I present the results of the first explicitly marine-focused, global assessment of MPAs in relation to three global marine protection targets. Approximately 2.35 million km2, equivalent to 0.65% of the world’s oceans, are currently protected, and only 12% of that is ‘no-take’. Over the last two decades, the marine area protected globally has grown at ~5% per year. At this rate, even the most modest target is unlikely to be met for at least several decades. The utility of large-scale conservation targets has been repeatedly questioned, although mainly on ecological grounds. However, if, as is suggested here, their primary role is to motivate behavioural change, then a more serious problem is that they seem to be failing in this regard, too. I explore possible reasons for this and suggest two main problems: firstly, an as yet unmet need to develop a hierarchical system of targets that reflects the multi-scale and pluralistic nature of ecological and political systems; and secondly, feedback mechanisms between political will, perceived attainability, and target formulation which may impede implementation of the targets. Since the adoption of the global targets, no implementation strategy has been developed, which may also impede target attainment. In order to fill this gap, I applied a rarity-complementarity heuristic place prioritisation algorithm (PPA) to a dataset consisting of 1038 global species distributions with 0.5° latitude/longitude resolution, under ten scenarios devised to reflect the global targets. This is the first time that species distribution ranges of marine species have been used in a globally synthetic way, and is by far the largest application of a PPA to date. Global priority areas for protection are identified for each scenario, which may be used to identify where regional-scale protected areas network design efforts might be focused.
74

Proton irradiation of gold targets for 197(m)Hg production

Walther, Martin, Preusche, Stephan, Pietzsch, Hans-Jürgen, Bartel, Stig, Steinbach, Jörg 19 May 2015 (has links) (PDF)
Introduction Irradiation of gold with protons provides access to no-carrier-added 197mHg and 197Hg. Interests in these radionuclides were awakened by the unique chemical and physical properties of mercury and its compounds combined with convenient nuclear properties like suitable half life (197mHg: T1/2 = 23.8 h, 197Hg: T1/2 = 64.14 h), low energy gamma radiations for imaging, Auger – and conversion electrons for therapy. The high thermal conductivity of gold enables high current irradiations and the monoisotopic natural abundance of 197Au supersedes expensive enrichment of the target material. The 197Au(p,n)197(m)Hg reaction was applied until now only for beam monitoring1, stacked foil meas-urements2 or very small scale tracer production. Material and Methods The irradiations were performed at a Cyclone 18/9 (IBA, Louvain la Neuve, Belgium). Its beam-line was sealed with a 1.0 mm vacuum foil (high purity aluminum, 99.999 %) from Goodfellow (Huntingdon, England). High purity gold disks (23 mm diameter, 2 mm thickness, 99.999% pure, 1 ppm Cu) as target material were purchased from ESPI (Ashland, USA). Gold foils as alternative gold targets (12.5×12.5 mm, 0.25 mm thickness, 99.99+ %, 1 ppm Cu) between an aluminum disk (22 mm diameter, 1 mm thickness, 99.0 %, hard) and an aluminum lid (23 mm diameter, 99.0 %, hard) were purchased from Goodfellow (Huntingdon, England). Hydrochloric acid (30%) and nitric acid (65%) were purchased from Roth (Karlsruhe, Germany) in Rotipuran® Ultra quality. Deionized water with > 18 MΩcm resistivity was prepared by a Milli-Q® system (Millipore, Molsheim, France). For separation of target material and side products a liquid-liquid extraction method (Gold was extracted with methyl isobutyl ketone (MIBK) from 2 M HCl target solution) and an ion exchange method (cation exchange resin (Dowex50W-x8, 100–200 mesh, H+ form) were applied. Results and Conclusion No-carrier-added 197(m)Hg was produced from gold via the 197Au(p,n)197(m)Hg reaction at proton energies of 10 MeV in sufficient quantity and quality for imaging studies. Two different methods were studied for the separation of Hg radionuclides generated from Au targets. The results demonstrate the possibility to produce 197(m)Hg from gold at low proton energies. Combined with the presented radiochemical separation methods, the 197Au(p,n) reaction could be the basis for repeatable production of 197(m)Hg for imaging and therapy research on sufficient activity level.
75

Saturation conditions in elongated single-cavity boiling water targets

Steyn, G. F., Vermeulen, C. 19 May 2015 (has links) (PDF)
Introduction It is shown that a very simple model reproduces the pressure versus beam current characteristics of elongated single-cavity boiling water targets for 18F production surprisingly well. By fitting the model calculations to measured data, values for a single free parameter, namely an overall heat-transfer coefficient, have been extracted for several IBA Nirta H218O targets. IBA recently released details on their new Nirta targets that have a conical shape, which constitutes an improvement over the original Nirta targets that have a cylindrical shape [1,2]. These shapes are shown schematically in FIGURE 1. A study by Alvord et al. [3] pointed out that elevated pressures and temperatures in excess of the saturation conditions may exist in a water target during bombardment. However, as long as the rate of condensation matches the rate of vaporization, the bulk of the system should remain at saturation conditions. Superheated regions are therefore likely to form but also likely to disappear rapidly, typically on the scale of a few milliseconds. Even though the boiling process is generally quite complex, enhanced by radiation-induced nucleation, the presence of fast mixing mechanisms in the water volume justifies some simplifications to be made. Materials and Methods The simplified model assumes that the bulk of the target water has a constant temperature, which is the same as the inner wall temperature of the cavity, Tw. A second simplification is to neglect the temperature difference across the target chamber wall, which is only justified if the wall is thin. The boiling is not explicitly taken into consideration, including the rather complex boiling behaviour at the Havar window, except to acknowledge that it is the main mixing mechanism. Large temperature gradients can briefly exist in the water medium but they also rapidly disappear. A further assumption is that a single, overall convective heat-transfer coefficient can be applied, which is constant over the entire water-cooled surface. As the wall thickness is neglected, the heat-transfer surface is assumed to be the inner surface of the cavity, excluding the surface of the Havar window. One can then write down an energy balance between the beam heating and the convection cooling (Newton’s law of cooling), where Ib is the beam intensity, ΔE is the energy windows of the target (taken as 18 MeV), h is the convective heat-transfer coefficient, A is the inner cavity surface through which the heat has to be transferred from the target-water volume to the cooling water, and T0 is the cooling-water temperature. The saturated vapour pressure of water versus temperature is a characteristic curve, given by the steam tables [4]. Assuming the bulk of the system at saturation conditions, one gets from (1) and (2). The function f is represented by a polynomial. The only unknown in Equation (3) is the overall convective heat-transfer coefficient h. Our approach was to adjust h until a good fit with a set of measured data was obtained. It also has to be mentioned that subtle differences in the physical properties between 18O-water and natural water have been neglected. All in all, quite a few assumptions and simplifications are made in deriving Equation (3) and the system is, admittedly, much more complex. Nevertheless, the results obtained by applying Equation (3) are rather interesting. Results and Conclusion Measured data and corresponding calculations are shown in FIGURE 2 for three different conical targets and one cylindrical target. The extracted convective heat-transfer coefficients are pre-sented in TABLE 1 for the four cavities. As can be seen in FIGURE 2, while there are some differences between the data and calculated curves, especially towards lower beam currents, the overall agreement is remarkably good. It is possible that the better agreement towards higher beam intensities is related to more ebullient boiling and more rapid mixing, i.e. closer to the conditions that the model assumes. The values obtained for the overall convective heat-transfer coefficient are also remarkably similar. This tells us that, by and large, all the cavities perform in a similar way and the performance in terms of maximum operational beam current depends largely on the available surface to effectively remove the heat from. The values of h increase marginally if a smaller value is adopted for the cooling water. Note that the choice of T0 = 30 ᵒC used to obtain the results in TABLE 1 is typical for the room temperature closed-loop cooling system used at iThemba LABS, once it has stabilized under operational conditions. A study by Buckley [5] on a quite different target design reports a value of h = 0.49 W cm−2 ᵒC−1, which is reassuringly similar. That study describes a cylindrical target cavity with a volume of 0.9 cm3, 8 mm deep, cooled with 25 ᵒC water from the back, operated with a 15 MeV proton beam with an intensity of 30 µA. The Nb Nirta targets are typically filled with 18O-water to about 60% of the cavity volume (see refs. [1,2] for the recommended values). The elongated shape, in combination with the ebullient properties of the boiling water, prevents burn-through. All the targets deliver the expected saturation yield. The targets are self-regulating ─ no external gas pressure is required. While the thermosyphon targets seemingly take advantage of a superior concept, we are now questioning whether this is really so in practice? It is not clear to us that the much more complex thermosyphon targets deliver any operational and/or performance advantages compared to the simple elegance of these elongated, single-cavity boiling target designs.
76

Theoretical analysis of the effect of target-thickness fluctuations on reaction-rate variability for proton-induced nuclear reactions on enriched Mo targets

Tanguay, J., Hou, X., Bénard, F., Buckley, K., Ruth, T., Schaffer, P., Celler, A. 19 May 2015 (has links) (PDF)
Cyclotron production of 99mTc through the 100Mo(p,2n)99mTc reaction1 is being actively investigated as an alternative to reactor-based approaches. A challenge facing cyclotron pro-duction of clinical-quality 99mTc is that proton bombardment of Mo targets results in production of a number of additional Tc and non-Tc isotopes through various reaction channels.2,3 While non-Tc products can be chemically re-moved, other Tc radioisotopes cannot and will therefore degrade radionuclidic purity and contribute to patient radiation dose.5 The radionuclidic purity of cyclotron-produced 99mTc depends on the nuclear cross section governing each reaction channel, the proton current and energy distribution, duration of bombardment, target thickness and isotopic composition. Although conditions that minimize dose from radioactive Tc impurities have been identified,5 cyclotron performance and thus irradiation conditions may randomly fluctuate between and/or during production runs. Fluctuations of certain parameters, for example the total number of bombarding protons, are expected to have little influence on radionuclidic purity, whereas fluctuations in beam energy, target thickness and isotopic composition may dramatically affect the relative amounts of 93gTc, 94gTc, 95gTc, and 96gTc impurities. It is critical to quantify relationships between potential fluctuations and the reproducibility and consistency of the radionuclidic purity of cyclotron-produced 99mTc to guide development and optimization of target preparation, irradiation, and processing techniques. The purpose of this work is to present a mathematical formalism for quantifying the relation-ship between random fluctuations in Mo target thickness and variability of proton-induced nuclear reaction rates for enriched Mo targets. In this study, we use 96gTc as an example of impurity which can potentially contribute to increased patient dose for patients injected with cyclotron-produced 99mTc.4 Herein, we apply the developed formalism to both the 96Mo(p,n)96gTc and the 100Mo(p,2n)99mTc reaction channels, however, the same approach can be applied to any reaction channel of interest.
77

Visual observation of boiling in batch-style water targets

Peeples, J., Stokely, M., Poorman, M., Magerl, M., Wieland, B. 19 May 2015 (has links) (PDF)
Introduction Batch-style water targets used for F-18 production are known to operate under boiling conditions in the target irradiation chamber, but the distribution of vapor under steady-state conditions was previously unknown. Thermal performance of batch targets has been correlated to average void in the target [1], but the simplified assumptions of such models do not represent the true non-uniform boiling behavior. Visualization targets can be used to observe boiling inside of a target during operation [2–5]. Commercial BTI targets operate at 28–35 bar (400–500 psi) with heat inputs of 0.5 to 3 kW and fill volumes of 1 to 4 mL. Recently, a visualization target featuring two transparent viewing windows was used to observe boiling conditions for realistic operating beam power, target pressure, and fill volume [4]. The same methodology has been applied to three additional visualization targets to examine the effect of target geometry on observed boiling phenomena. Material and Methods The original visualization target featured an aluminum body with a 0.127 mm (0.005 inch) integral aluminum beam window and two viewing windows made of optically clear sapphire (Al2O3). It was operated on an IBA 18/9 cyclotron with 18 MeV protons at beam power up to 1.1 kW, for pressures of 5 to 21 bar (70 to 300 psi), and a fill volume of 2.5 mL. All of the new designs featured a wider chamber to allow for higher beam transmission and an increased chamber height, consistent with cur-rent trends in high power targets. One target featured a reduced chamber depth, and another had a ramp in the back of the chamber to reduce fill volume. Target pressure was limited to a maximum of 14 bar (200 psi) due to the larger diameter beam window. A video camera was used to record the boiling conditions observed for each target under several lighting conditions. During irradiation, the proton beam excites the water molecules, producing visible blue light emissions during de-excitation. These light emissions provide a good indication of beam distribution and penetration depth. A strong backlight can be used to produce clearer images of bubbles generated during boiling. Results and Conclusion Proton range and visible blue light emissions were recorded in dark ambient conditions. The width of the Bragg peak and natural circulation in the bulk fluid were visible with good ambient lighting. Size and distribution of vapor bubbles could be observed by using a strong backlight. The beam current was increased gradually to determine the thermal limit for each target for several fill volumes and pressures. Two thermal limits were observed which resulted in some beam penetration in the top region of the beam. For lower fill volumes, steam ac-cumulates in or around the helium overpressure bubble, causing the helium bubble to move into the upper region of the beam. For higher fill volumes, beam penetration occurs due to excessive voiding, when bubbles produced in the beam region cannot rise quickly enough out of the path of the beam.
78

High power conical-shaped Niobium targets for reliable [18F-] production and lower [18O] water consumption

Devillet, F., Geets, J.-M., Ghyoot, M., Kral, E., Mooij, R., Nactergal, B., Vosjan, M. 19 May 2015 (has links) (PDF)
Introduction In order to address the increasing demand for Fluorine-18 and the rising cost per mL of 18O enriched water, IBA developed improvements to their 18F- production systems. For this new design we started from scratch, with the main objectives of reducing the required enriched water volume and improving the cooling of the insert. A better cooling allows increasing the target current and thus the produced activity. Finally, we aimed to reduce the number of parts and improve the design of auxiliary components. Material and Methods Six Niobium conical inserts with different target chamber volumes were machined and tested. Only 4 of these were selected to create the new range of IBA 18F− targets shown in TABLE 1. The new Niobium target inserts have a complex shape with drilled channels on the outside of the chamber and a deep channel next to the beam strike area (FIG. 1, green circle) to ensure efficient cooling. The 18O water inlet lines are now directly inserted in the Niobium body (FIG. 1, blue circle) to improve 18F- quality (no more contact with small o-rings). In operation, a 35µm Havar® target window is used. All tests were performed using IBA Cyclone® 18 cyclotron. The targets were filled with different volumes of enriched 18O water (enrichment > 92 %) and irradiated with 18 MeV protons on target with beam currents up to 145 μA for 30 to 150 minutes, while the internal pressure rise of the target was recorded. For each target, a pressure-current curve was plotted and an optimum balance between target water fill volume, pressure and current has been determined, which maximises available activity after two hours, in each case. Results and Conclusion Radionuclidic impurities were measured and more than 100 FDG syntheses on various synthesizers confirmed the effectiveness of the new design. Increasing the current up to 145µA in Conical 16, the production reached 18 Ci in 2 hours, single beam, with a target pressure under 43 bar. Today, the use of these new targets for daily commercial production is increasing within the IBA Cyclone® installed base.
79

Preprocessing issues in high resolution radar target classification / by Anthony Zyweck.

Zyweck, Anthony January 1995 (has links)
Bibliography: leaves 287-294. / xviii, 294 p. : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis addresses preprocessing issues for radar target classification from high resolution radar imagery. High resolution radar imagery of real aircraft in flight and of a MIRAGE aircraft on a turntable is examined. An algorithm to coherently average high resolution range profile is proposed. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1995
80

Preprocessing issues in high resolution radar target classification /

Zyweck, Anthony. January 1995 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1995? / Includes bibliographical references (leaves 287-294).

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