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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.
1

Cretaceous and Tertiary megafloras from New Zealand and their climate signals

Kennedy, Elizabeth Mary January 1998 (has links)
No description available.
2

ROCKET MOTOR PLUME EFFECTS ON TM SIGNALS - MODEL CORROBORATION

Johnston, Jerry W., LaPoint, Steve 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / This paper presents the interim results of an effort to corroborate analytic model predictions of the effects of rocket motor plume on telemetry signal RF propagation. When space is available, telemetry receiving stations are purposely positioned to be outside the region of a rocket motor's plume interaction with the RF path; therefore, little historical data has been available to corroborate model predictions for specific rocket motor types and altitudes. RF signal strength data was collected during the flight of HERA target missile by White Sands Missile Range (WSMR) using a transportable telemetry receiving site specifically positioned to be within the rocket plume region of influence at intermediate altitudes. The collected data was analyzed and compared to an RF plume attenuation model developed for pre-mission predictions. This work was directed by the US Army Kwajalein Atoll (USAKA)/ Kwajalein Missile Range (KMR) Safety Division.
3

Economic analysis of recovering solid wood products from western hemlock pulp logs

Mortyn, Joel William 05 1900 (has links)
The purpose of this research was to quantify what value could be gained from cutting solid wood products from old-growth western hemlock (Tsuga heterophylla (Raf.) Sarg.) logs that are used to produce pulp in British Columbia. These logs represent a significant portion of the resource and increasing their value recovery would be beneficial to the forest industry. One hundred and sixteen logs were sampled from the coastal and interior regions of British Columbia. Dimension and quality attributes were measured to enable estimates of gross and merchantable volume. Logs deemed likely to yield lumber were sawn with the aim of maximizing value recovery. The nominal dimension and grade of all lumber recovered was recorded. Margins and breakpoints at which sawing became profitable were calculated. Models to predict the volume of lumber and proportion of Clear grade lumber recovered (“C Industrial” grade at the interior mill, “D Select” grade at the coastal mill) were developed. Lumber recovery, especially Clear grade lumber, was significantly higher from logs from the coastal site. At current market prices, cutting lumber from these logs was profitable, with the highest margins achieved when chips were produced from the milling residue. It was not profitable to recover lumber from the interior logs regardless of whether chips were produced. The disparity between locations was attributed to differences between the logs, the sawmilling equipment, the sawyers’ motivations and the lumber grades. Between 60% and 67% of coastal logs and 13% to 21% of interior logs returned a profit, depending on whether chips were produced. Models were developed to better identify these logs using observable attributes. A linear model described the total volume of lumber recovered. Significant predictor variables in the model were the gross log volume, the average width of the sound collar and the stage of butt/heart rot at the large end. A second model predicted the proportion of Clear grade lumber. Regional models were developed to account for different Clear lumber grades between sawmills. Significant predictor variables were knot frequency, diameter at the large end, volume, length, taper and the width of the sound collar at the large end.
4

Economic analysis of recovering solid wood products from western hemlock pulp logs

Mortyn, Joel William 05 1900 (has links)
The purpose of this research was to quantify what value could be gained from cutting solid wood products from old-growth western hemlock (Tsuga heterophylla (Raf.) Sarg.) logs that are used to produce pulp in British Columbia. These logs represent a significant portion of the resource and increasing their value recovery would be beneficial to the forest industry. One hundred and sixteen logs were sampled from the coastal and interior regions of British Columbia. Dimension and quality attributes were measured to enable estimates of gross and merchantable volume. Logs deemed likely to yield lumber were sawn with the aim of maximizing value recovery. The nominal dimension and grade of all lumber recovered was recorded. Margins and breakpoints at which sawing became profitable were calculated. Models to predict the volume of lumber and proportion of Clear grade lumber recovered (“C Industrial” grade at the interior mill, “D Select” grade at the coastal mill) were developed. Lumber recovery, especially Clear grade lumber, was significantly higher from logs from the coastal site. At current market prices, cutting lumber from these logs was profitable, with the highest margins achieved when chips were produced from the milling residue. It was not profitable to recover lumber from the interior logs regardless of whether chips were produced. The disparity between locations was attributed to differences between the logs, the sawmilling equipment, the sawyers’ motivations and the lumber grades. Between 60% and 67% of coastal logs and 13% to 21% of interior logs returned a profit, depending on whether chips were produced. Models were developed to better identify these logs using observable attributes. A linear model described the total volume of lumber recovered. Significant predictor variables in the model were the gross log volume, the average width of the sound collar and the stage of butt/heart rot at the large end. A second model predicted the proportion of Clear grade lumber. Regional models were developed to account for different Clear lumber grades between sawmills. Significant predictor variables were knot frequency, diameter at the large end, volume, length, taper and the width of the sound collar at the large end.
5

Economic analysis of recovering solid wood products from western hemlock pulp logs

Mortyn, Joel William 05 1900 (has links)
The purpose of this research was to quantify what value could be gained from cutting solid wood products from old-growth western hemlock (Tsuga heterophylla (Raf.) Sarg.) logs that are used to produce pulp in British Columbia. These logs represent a significant portion of the resource and increasing their value recovery would be beneficial to the forest industry. One hundred and sixteen logs were sampled from the coastal and interior regions of British Columbia. Dimension and quality attributes were measured to enable estimates of gross and merchantable volume. Logs deemed likely to yield lumber were sawn with the aim of maximizing value recovery. The nominal dimension and grade of all lumber recovered was recorded. Margins and breakpoints at which sawing became profitable were calculated. Models to predict the volume of lumber and proportion of Clear grade lumber recovered (“C Industrial” grade at the interior mill, “D Select” grade at the coastal mill) were developed. Lumber recovery, especially Clear grade lumber, was significantly higher from logs from the coastal site. At current market prices, cutting lumber from these logs was profitable, with the highest margins achieved when chips were produced from the milling residue. It was not profitable to recover lumber from the interior logs regardless of whether chips were produced. The disparity between locations was attributed to differences between the logs, the sawmilling equipment, the sawyers’ motivations and the lumber grades. Between 60% and 67% of coastal logs and 13% to 21% of interior logs returned a profit, depending on whether chips were produced. Models were developed to better identify these logs using observable attributes. A linear model described the total volume of lumber recovered. Significant predictor variables in the model were the gross log volume, the average width of the sound collar and the stage of butt/heart rot at the large end. A second model predicted the proportion of Clear grade lumber. Regional models were developed to account for different Clear lumber grades between sawmills. Significant predictor variables were knot frequency, diameter at the large end, volume, length, taper and the width of the sound collar at the large end. / Forestry, Faculty of / Graduate
6

Effect of the adhesive strategy on clinical performance and marginal integrity of a universal adhesive in non-carious cervical lesions in a randomized 36-month study

Stache, Gesa 07 June 2024 (has links)
The effectiveness of a universal adhesive applied in three application modes for the preparation of Class V composite restorations was evaluated both clinically and by quantitative marginal analysis (QMA) over 36 months. In 50 patients, three (n = 21) or four (n = 29) non-carious cervical lesions (NCCL) were restored with Venus® Diamond Flow (Kulzer GmbH, Hanau, Germany).The adhesive iBond® Universal (iBU, Kulzer, Germany) was used in self-etch (SE), etch-and-rinse (ER), or selective-enamel-etch mode (SEE).The etch-and-rinse adhesive OptiBondTM FL served as a control (OFL, Kerr GmbH, Herzogenrath, Germany).The restorations were clinically assessed (FDI criteria) at 14 days (BL), 6, 12, 24, and 36 months. Additionally, QMA was conducted on all restorations of 11 randomly selected patients. FDI criteria and marginal gap and perfect margin were compared between and within groups and recalls using McNemar, Wilcoxon, or Mann–Whitney-U-tests (α = 0.05). Starting with 12 months, cumulative failure rates were lower in iBU-SE (0.0%, p = 0.016) and iBU-ER groups (2.1%, p = 0.07) compared to OFL (16.7%). At two years, iBU-SEE also showed fewer failures (0.0%SEE vs. 34.6%OFL, p = 0.016), as did iBU-SE compared to iBU-ER after 36 months (2.2 and 19.6%, p = 0.039). From BL, the iBU-SEE group always had the fewest marginal gaps and the highest percentage of perfect margins. From BL, iBU-SEE (0%, p = 0.008) and iBU-ER (0.2%, p = 0.027) showed significantly fewer marginal gaps compared to OFL (2.5%) and more perfect margins were found with iBU-SEE starting at 6 months (p = 0.054).The SEE and ER modes ensured the most excellent marginal quality, with differences from the control appearing earlier with QMA than clinically. In restoring NCCls, iBU showed superior clinical performance over OFL, especially in modes SE and SEE.
7

Der Einfluss einer vereinfachten Applikationstechnik auf das Randverhalten von Keramikinlays

Clotten, Stefan 09 January 2004 (has links)
Die adhäsive Befestigung von keramischen Inlays erfordert viele mühsa-me und zeitintensive Arbeitsschritte. Zudem werden die Dentin-Bonding-Materialien nicht nach den Herstellerangaben verarbeitet, was unter Um-ständen einen negativen Einfluss auf die Randqualität von keramischen Inlays deren Ränder sich im Dentin befinden können, haben kann. Ziel der Untersuchung: In dieser Studie wurde der Einfluss einer verein-fachten Applikationstechnik auf die Randqualität keramischer Inlays un-tersucht. Material und Methode: MOD-Inlaykavitäten mit Präparationsgrenze im Dentin wurden in 32 humane kariesfreie Prämolaren präpariert. Die Prä-molaren wurden zufällig in vier Gruppen geteilt (n=8). In dem Ver-suchsaufbau war ein Untersuchungsparameter das Inlaymaterial (Empress/Cerec) und der andere die Polymerisation des Dentin-Bonding-Materials vor Insertion des Inlays (P+) und nach Insertion des Inlays (P). Alle Inlays wurden mit einem Dualzement (Variolink II) in Kombination mit einem schmelz- und dentinkonditionierenden Universal-Bonding-Material (Etch & Prime 3.0) eingegliedert. Drei Parameter wurden verwandt, um die Qualität der Versorgung zu bestimmen: 1. Die Passung, gemessen durch die Differenz der Einsenktiefe in die Kavität zwischen der Anprobe und nach dem Zementieren, 2. die Randqualität, die mittels quantitativer Randanalyse im SEM bei einer 200fachen Vergrößerung vor und nach Temperaturlastwechsel (2000 mal zwischen 5° und 55° C) durch Replikas aus Epoxydharz bestimmt wurde und 3. die Randdichtheit, überprüft mit einem Farbstoffpenetrationstest (0,5% wässrige Lösung von basischem Fuchsin). Ergebnisse: Die statistische Analyse (ANOVA) ergab: In allen vier Gruppen waren die Inlays nach der Eingliederung > 5µm tiefer in der Kavität, als bei der Anprobe. Das Ergebnis war für die Gruppe Cerec-Inlays bei denen das Dentin-Bonding vor dem Eingliedern nicht polymerisiert wurde signifikant größer. Die statistische Auswertung der Randanalyse nach dem Friedman und Wilcoxon Test ergab für die zervikalen Bereiche für beide getesteten Kriterien keine statistisch signifikanten Unterschiede (p< 0,01). Die Median-werte für alle Gruppen zeigten 100 Prozent klinisch akzeptable Ränder und keine Randspalten. Der Farbstoffpenetrationstest ergab 71 Prozent dichte Ränder im Schmelz und 38 Prozent dichte Ränder im Dentin. Schlussfolgerung: Bei der Verwendung des universal Bonding-Materials ist es möglich, hohe Randqualitäten mit keramischen Inlays im Schmelz und Dentin selbst mit einer vereinfachten Applikationstechnik, zu erzielen. / The adhesive luting technique for ceramic inlays requires a sequence of multiple steps that are cumbersome and time consuming. Furthermore, modifications of dentin bonding procedures may negatively influence the margin quality of ce-ramic inlays with cervical dentin finishing lines. Purpose: The objective of this study was to test the effect of a new, sim-plified procedure for dentin bonding on the margin quality of ceramic inlays. Materials and Methods: Thirty-two MOD inlay cavities with cervical finish-ing lines in dentin were prepared into premolars. They were randomly di-vided into four groups (n = 8): In the balanced design, one parameter was the inlay material (Empress/Cerec) and the other the polymerization of the dentin bonding agent, before insertion of the inlay (P+) and after in-sertion of the inlay (P-). All inlays were inserted with dual cured cement (Variolink II) in combination with an enamel and dentin conditioning uni-versal bonding agent (Etch & Prime 3.0). Three parameters were used to determine the inlay margin quality: (1) the fit, measured by the difference of the insertion depth into the cavity between try-in and cementation, (2) a quantitative margin analysis in the SEM at a magnification of 200xs, be-fore and after thermocycling (2000 times between 5 and 55 degrees cen-tigrade), using epoxy replicas and (3) dye penetration. Results: Statistical analysis using the ANOVA test showed in all four groups the inlays were >5 µm deeper in the cavities than at the try-in ses-sion. This is explained by the substance loss from the etching. The measured difference for Cerec inlays inserted in cavities, where the bond-ing agent was not polymerized prior to insertion, was significantly larger. Statistical interpretation of the margin analysis of the cervical segment using the Friedman and Wilcoxon Test revealed no statistical differences (p< 0.01) for both criteria tested. The median values for all groups were 100% for clinical acceptable margin and 0% for marginal opening. The dye penetration test resulted in 71% of the enamel margins and 38% of the dentin margins. Conclusion: By using the universal bonding agent, high margin qualities on dentin and enamel are obtained with ceramic inlays even with the sim-plified approach.
8

Der Einfluß der Ausarbeitung mit verschiedenen rotierenden Instrumenten auf die Randqualität und Oberflächenmorphologie von zahnfarbigen lichthärtenden Restaurationen

Bunte, Henning 19 November 2001 (has links)
In dieser Studie wurde das Verhalten eines neuentwickelten Hartmetallfinierers der Firma Brasseler und herkömmlicher grober und feiner Diamantfinierer der Firmen Intensiv und Brasseler an vier verschiedenen Füllungsmaterialien untersucht. Bei dem Hartmetallfinierer handelt es sich um ein Kombinationsinstrument, das sich im Rechtslauf durch eine hohe Arbeitsleistung auszeichnet und zum Konturieren von Füllungen gedacht ist. Im Linkslauf soll das Instrument zur Feinausarbeitung eingesetzt werden, die Arbeitsleistung ist geringer. In 120 extrahierte menschliche Zähne wurden ovale Klasse-V-Kavitäten (Länge: 4 mm, Breite: 3 mm, Tiefe: 2 mm) präpariert, die jeweils zur Hälfte im Schmelz und Dentin lagen. Jeweils 30 Zähne wurden nach Herstellerangaben mit demselben Füllungsmaterial gefüllt (Prodigy, Silux Plus, Dyract AP, Fuji LC). Anschließend wurden die Restaurationen zunächst mit den gröberen Finierdiamanten und dem Kombifinierer im Rechtslauf konturiert. Jeweils 10 Proben eines jeden Füllungsmaterials wurden mit einem der Instrumente bearbeitet. Auf diese Weise ergaben sich 12 Material-Instrumenten-Kombinationen. Nach dreiwöchiger Wasserlagerung wurde die Rauhigkeit der Füllungsoberflächen mit einem Profilometer gemessen. Außerdem erfolgte eine Auswertung der Randqualität mittels quantitativer Randanalyse. Im Anschluß hieran wurden die Füllungen mit den feineren Diamantinstrumenten bzw. dem Kombifinierer im Linkslauf finiert. Die Füllungen wurden anschließend einer Temperaturwechselbelastung unterzogen (2000 Zyklen zwischen 5°C und 55°C). Erneut erfolgte eine quantitative Randanalyse und eine Oberflächenrauhigkeitsmessung. Die statistische Auswertung der Daten ergab, daß der Kombifinierer im Linkslauf im Gegensatz zu den feinen Diamantfinierern keine Verbesserung der Oberflächenqualität bewirkt. Die Auswirkungen der Instrumente auf die Randqualität ist gleich. Fuji LC weist die höchste Oberflächenrauhigkeit auf. Die übrigen Füllungsmaterialien unterscheiden sich diesbezüglich nicht statistisch signifikant voneinander. Die Silux Plus Restaurationen zeichnen sich durch einen im Vergleich zu den übrigen Materialien hohen Anteil an Randspalten sowohl im Dentin- als auch im Schmelzbereich aus. Die Prodigy Füllungen haben signifikant mehr Randspalten im Dentin als Fuji LC und Dyract AP Füllungen, jedoch auch signifikant weniger als Silux Plus im gleichen Bereich. / In this study a newly developed tungsten carbide finishing bur (Brasseler) and conventional coarse and fine grit finishing diamonds of the companies Intensiv and Brasseler were studied with four different filling-materials. The carbide bur is a combination-instrument, that distinguishes itself in the right-hand rotation by a high performance and is intended for the contouring of fillings. When used in a left-hand rotation the instrument should be applied for polishing. In this case the cutting performance is inferior. Oval class-V-cavities (length: 4 mm, width: 3 mm, depth: 2 mm) were prepared into 120 extracted human teeth with one half of the margin length in dentin and one half in enamel. In each case, 30 teeth were filled according to manufacturer-recommendation with the same filling-material (Prodigy, Silux Plus, Dyract AP, Fuji LC). Subsequently the restorations were trimmed with the coarser finishing diamonds and the combination bur with a right-hand rotation. Ten samples of each filling-material were ground with one of the instruments. Thus 12 material-instrument-combinations were established. After three weeks of water-storage, the surface roughness of the fillings was measured with a profilometer. Furthermore, an evaluation of the margin-quality was carried out by means of quantitative margin analysis. After this, the fillings were either polished with the finer diamond-instruments or with the combination-instrument in a left-hand rotation. Afterwards the samples were subjected to a thermocycling procedure (2000 cycles between 5°C and 55°C). Again a quantitative margin analysis and a surface-roughness-measurement were performed. In contrast to the fine diamond instruments, the statistical evaluation of the data revealed that the combination finishing bur does not improve the surface quality in a left-hand rotation. The effect of the instruments on the margin quality is the same. Fuji LC shows the highest surface-roughness, the other filling-materials do not differ statistically significantly from one another. The Silux Plus restorations are characterized by a high percentage of marginal openings in both enamel and dentin. The Prodigy fillings show significantly more marginal gaps in dentin than Fuji LC and Dyract AP fillings, but significantly less than Silux Plus in the same area.
9

Economic assessment of indigenous leafy vegetables (ILVs) production for income generation and food income generation and food security in the Eastern Cape Province, South Africa

Mayekiso, Anele January 2021 (has links)
Thesis (Ph.D. (Agricultural Economics )) -- University of Limpopo, 2021 / Regardless of the strategies adopted globally and nationwide to fight food insecurity within communities, particularly in the rural context, poverty becomes a major constituent which translates to most rural households experiencing food insecurity shocks. Given the high unemployment rate in South Africa which triggers several household’s vulnerability to food insecurity, the country has diverse natural resources which include indigenous plants such as Indigenous Leafy Vegetables (ILVs), which can be used as food and for business purposes by its residents. Irrespective of the diversity of ILVs in South Africa, there is a significant decline in the production and consumption of ILVs particularly in rural areas where these vegetables are mostly available. In addition, production and consumption of ILVs may not only address food insecurity but these vegetables may benefit households through the income obtained from their sales. The income generated from sales of ILVs may therefore assist towards improving and sustaining rural livelihood needs. Given this background information, the study aimed at assessing ILV production for income generation and food security among rural households in the Eastern Cape Province (ECP) of South Africa. The study was conducted within the three district municipalities of the ECP which were selected because statistics report these districts to be the most affected areas by poverty within the province. These districts are OR Tambo District Municipality (ORTDM), Alfred Nzo District Municipality (ANDM) and Joe Gqabi District Municipality (JGDM). Multistage and proportional random sampling procedures were employed to select households which could participate in the study. Thus, 407 households within these three (3) districts municipalities were used for the purposes of the study. The study also included interviewing role players within the ILV production value chain, thus a snowball sampling procedure was used to select role players. Sixteen hawkers and three input suppliers were interviewed from the three district municipalities. In addition, from the 407 households that were interviewed, 260 households from the three district municipalities reported to be producers of ILVs. A structured questionnaire was therefore used to collect pertaining data allied in achieving the aim of the study. The collected data was captured using Excel 2016, after data cleaning, it was then exported to Statistical Package for Social Sciences (SPSS) version 25 for analysis. Numerous analytical models were used from SPSS 25. For instance, to identify and describe socio-economic characteristics of households, to assess the most produced ILVs from the study areas and to identify role players within the ILV production value chain, descriptive statistics in a form of means, percentages, frequencies, and standard deviation was used. To determine factors which influence production of ILVs, a Binary Logistic Regression Model was used. A Multinomial Logistic Regression model was used to determine factors which influence different uses of ILVs by households and to determine factors influencing food security status among households. A gross margin analysis was used to estimate viability from each ILV produced, harvested and sold, while Household Food Insecurity Access Scale (HFIAS) was used to measure food security status among households. Lastly, a correlation matrix was also used to determine the relationship between the role players and their functions among the ILV production value chain. Based on the results, the study therefore concluded that, from the three district municipalities used in the study, there are various ILVs growing naturally and produced. The production of ILVs from these municipalities is habituated by socio economic characteristics of households, wherein households use ILVs for various purposes which include these vegetables as source of food, medicine and livestock feed. The use of ILVs among households is influenced by socio-economic characteristics and seasonal availability of ILVs in ORTDM, while in ANDM and JGDM, the use of ILVs by households is conditioned by socio-economic characteristics of households, knowledge/ awareness related to nutrition and health benefits of ILVs and seasonal production of ILVs. Furthermore, this research concludes that, ILVs have a potential of diversifying diets and addressing food insecurity problems within rural parts of the three districts. Given the positive gross margins from the three districts, production and selling of ILVs has a potential to contribute to rural household income. Lastly, the study concludes that, the ILV production value chain system lacks governmental support in the form of institutional engagement since there is no evidence of extension officer support from these three district municipalities concerning ILVs production. To this end, the study recommends that, policy makers should further establish inclusion of ILVs in both farming and food systems. Also, government and related institutions which focus on sustainable rural development must intervene in promoting production of ILVs particularly within rural contexts since production of these vegetables may alleviate poverty through job creation, addressing food insecurity and income generation. Thus, a successful intervention of government and policy makers in ILV production would have a potential of translating to sustainable rural livelihoods / National Research Foundation (NRF)
10

Využití controllingu v podniku / Application of Management Control System in a Company

Zemánek, Zdeněk January 2014 (has links)
The aim of this thesis is to evaluate management control system in a company and pro-pose measures for better use of management control system as a subsystem of manage-ment of the company supporting the achievement of business objectives of the owners in the changing market environment. Thesis consists three main parts. The first theoretical part contains information about management control system. Analysis of the current state of management control system describes state of the management control system in a company and in the last section are suggestions for possible improvements of man-agement control system.

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