The object of this study is a new approach to the problem of replacement of assets which deteriorate and become obsolete with time. The investigator views replacement theory as a subset of capital budgeting. Capital budgeting has received much more attention, has benefited from many advances in mathematical programming techniques, and in general has been advanced to a much more sophisticated state of the art than has replacement theory. The approach taken in this work is to point out this divergence in advances in these areas by surveying the literature in each. Next a new approach to the replacement problem is presented. This approach is new in that it attacks the replacement problem as a system of interacting components rather than take the normal replacement approach to a single machine. The production process is modeled as a network in which each machine is represented by an arc. A single machine or two or more machines in parallel compose a stage of the process. Several stages are combined to complete the network. The general model is formulated as a mixed zero-one programming problem for a finite planning horizon. This model can be further modified by adding specialized constraints to make it fit more specific cases. The general model has provisions for equivalence relationships to carry funds forward or backward through time. It also takes into account such items as process requirements and machine capacities. Difficulties are encountered in that a normal problem is too large to solve. Further study reveals that by making a conservative assumption of using a single interest rate the problem can be reduced to a much smaller zero-one programming problem. This formulation for a reasonably sized production process is small enough to be solved by zero-one algorithms available in the literature. An example problem is formulated for illustrative purposes. / Ph. D.

Quality and availability of tall fescue (Festuca arundinacea Schreb.) accumulated for fall and winter pasture was influenced by starting dates of accumulation, season of growth, and by the addition of legumes. In 1975 and 1976, 60-day regrowths of tall fescue were evaluated (in vivo) for summer quality when fed alone and in 50:50 grass-legume mixtures to sheep. In 1975, 40-day old alfalfa (Medicago sativa L.) growth and in 1976, 60-day old red clover (Trifolium pratense L.) growth were used as legume treatments. In 1976, 60-day old orchardgrass (Dactylis glomerata L.) regrowth was fed alone and in a clover mix for comparison. Tall fescue was accumulated from mid-June, July, August, and September, fertilized with 112 kg N/ha in August, and fed in December to determine the effect of stockpiling date on in vivo quality. The effect of stockpiling date and N fertilization on yield, yield distribution, and chemical quality of fescue in winter were studied. The total digestible nutrient (TDN) content of tall fescue in summer was variable between years (35.3% in 1975 and 52.2% in 1976). Alfalfa (54.9% TDN) was higher in digestibility in 1975 than tall fescue, but red clover (52.6% TDN) and orchardgrass (52.6% TDN) were similar to tall fescue in 1976. There were no significant differences in intake of the forages. There was a consistent, nonsignificant increase in the digestibility of grass-legume mixes over the average digestibilities of the component feeds. The digestibilities of either summer grown tall fescue forage were considerably lower than those of the stockpiled tall fescue forages if accumulated from July, August, or September (60.2%, 61.6%, 61.6% TDN, respectively). June stockpiled forage (56.9% TDN) was lower in digestibility than the other stockpiling treatments but higher than for the summer grown tall fescue. In 1975, the DM intake (% bodyweight) of accumulated forage increased as stockpiling was delayed (June, 2.04% July, 2.41%; and August, 2.52%). In 1976, the digestibilities of all stockpilings were lower than in 1975. Digestibility increased as the accumulation periods were shortened from June to August (June, 52.0%; July, 56.7%; and August, 61.5% TDN) and then decreased for the shortest accumulation period (September, 54.5% TDN). The 1976 August accumulated growth was divided into top and bottom canopy strata; these strata (62.2% and 60.5% TDN, respectively) did not differ significantly in digestibility from the whole canopy (61.5% TDN). Intake in 1976 was not significantly affected by stockpiling periods or canopy strata. The digestible protein (DP) content of tall fescue for all summer and winter treatments was highly correlated to the crude protein (CP) content. There was a decrease in December dry matter (DM) yields as stockpiling and N fertilization was delayed from June to September. Generally, the best yield response for winter grazing occurred when N was applied at the date of stockpiling. Total yields decreased as stockpiling and fertilization was delayed. The highest total yields were obtained by fertilizing with N in June or July. Regrowth yields during summer were highest from early harvests but the yield distribution was shifted by N fertilization. The winter quality of accumulated tall fescue increased as yields decreased with delaying dates of stockpiling and fertilization. Total nonstructural carbohydrates (TNC 88 % of DM) increased from 14.7% to 30.5% in 1975 and from 11.8% to 28.0% in 1976; CP content increased from 8.2% to 15.5% in 1975 and from 8.2% to 13.9% in 1976 when stockpiling and fertilization were delayed from June to September. However, the yield of TNC and CP decreased as DM yield decreased. The relative chlorophyl content increased in canopies with delayed stockpiling and fertilization. Fertilization with N increased forage quality and resistance to early winter freezing. Yield and quality of tall fescue in February was lower than but highly correlated to the December yield and quality. / Ph. D.

Part A 2-Methyl-3-o-tolyl-4(3H)-quinazolinone (Methaqualone) and various other 2-methyl-3-aryl-4(3H)-quinazolinones were functionalized by active hydrogen condensations at the 2-methyl position. For example, methaqualone was metalated at the lateral 2-methyl group with lithium diisopropylamide at O⁰ in tetrahydrofuran (THF) and the resulting lithio salt was condensed with various electrophiles including alkyl halides and carbonyl compounds. Results of aldol condensations involving the lateral lithio salt of methaqualone revealed the severe steric requirements imposed upon this nucleophile by the 3-o-tolyl group. For instance, the secondary alcohol resulting from condensation with benzaldehyde underwent facile retroaldol condensation or dehydration. These degradative processes apparently relieve the extreme van der Waals repulsions between the 3-o-tolyl group and the bulky 2-(2-hydroxy-2-phenylethyl) substituent. These steric interactions were further evidenced by the ¹H NMR spectrum of this alcohol which revealed the existence of diastereomeric rotational isomers. A comparison between aldol condensations involving the less hindered lithio salt of 2,3-dimethyl-4(3H)-quinazolinone and the lithio salt of methaqualone further demonstrated the importance of the steric constraints in the latter anion. Sodium hydride promoted acylations at the 2-methyl group of methaqualone were achieved in refluxing 1,2-dimethoxyethane (DHE) with ethyl acetate as well as with various nonenolizable esters, such as ethyl trifluoroacetate and substituted benzoate esters. Since these acylations afforded the desired 2-(2-ketoalkyl)-3-o-tolyl-4(3H)- quinazolinones in good yield, and since these products represented a totally new class of 2-substituted-3-aryl-4-(3H)-quinazolinones, various other esters were employed in this synthetic scheme to prepare a representative group of derivatives of this pharmacologically active parent molecule. Likewise, other 2-methyl-3-aryl-4(3H)-quinazolinones were similarly acylated and a preliminary structure-activity correlation with respect to CNS depression and anticonvulsant activity was derived. Part B The use of potassium hydride to achieve possible twofold kaliation of acetylacetone and benzoylacetone was investigated. As expected, the hydride readily ionized the methylene proton of these diketones at room temperature in THF to form the expected monoanions. After refluxing the monoanion of acetylacetone in the presence of excess potassium hydride for 4 hours, evidence for formation of the 1,3-dianion was obtained by measurement of hydrogen evolution and trapping experiments using benzyl chloride and benzophenone to form the corresponding terminal derivative of the diketone. Addition of benzophenone to a THF solution of the monopotassio salts of acetylacetone and benzoylacetone at room temperature resulted in rapid evolution of a second equivalent of hydrogen and formation of the tertiary alcohols derived from condensation of benzophenone at the terminal methyl group of the diketone. A detailed study of the mechanism of this reaction was carried out. Several possible mechanisms were discarded. A proposed sequence of steps involving complexation of benzophenone with the diketone monoanions prior to ionization of a terminal methyl proton of the monoanion is presented. / Ph. D.

The morphological features of <i>Nivatogastrium nubigenum</i> are compared with closely related gastromycetes and lamellate agarics. Only one genus, <i>Pholiota</i> in the Cortinaricaeae, was found to have many features similar to <i>N. nubigenum</i>. The subgenus <i>Flammuloides</i> has many features in common with this gasteromycete. The fruiting bodies and cultural characteristics of <i>P. decorata, P. scamba, P. spumosa, and P. subangularis</i> are compared with <i>N. nubigenum</i>. All of the fungi studied are found in the western United States on conifer wood. Smooth, brown, thick-walled spores, large cystidia, and a somewhat visicid pileus are found in these species. Thick-walled cystidia, similar to those found in <i>P. decorata</i>, are reported for the first time in <i>N. nubigenum</i>. Growth rates, oxidase reactions, and morphological features were found to be similar for <i>N. nubigenum, P. decorata. and P. spumosa</i>. Positive oxidase tests, oidia, amorphous refractive bodies, "textura intricata" and inflated hyphal cells were found in these three similar species. Different media were used and additional morphological features were found that can be used to distinguish the species. / Master of Science

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (M.S.)--Joint Program in Marine Environmental Systems, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1998. / Includes bibliographic references (p. 79). / by Charles E. Rawson. / M.S.

There has been a misconception that there was no political party in Hong Kong before the 1980s, and that the Hong Kong people cared less about political reforms before the 1990s. This misconception is reinforced by various discourses such as the “lifeboat” theory, the “administrative absorption” theory, and the national characteristic of the Chinese people. Through a historical study of the Reform Club of Hong Kong and the Hong Kong Civic Association in the early postwar period, we come to a clear picture of the history of political development in Hong Kong. First, Hong Kong people were not indifferent to politics, although constitutional reforms made little progress before the 1980s. Second, early form of political party did exist before the 1980s. / The Reform Club of Hong Kong and the Hong Kong Civic Association were more than pressure groups but could be defined as political parties to pursue political, economic and social reforms in Hong Kong. Serving as the bridge between the Government and the people, they were particularly interested in such social issues as the urban development, housing, medicare, economy, education, crime, and hawking. Although the two parties often took a critical stance towards the Government, the Government used them to communicate with the people and to balance of interest of different political forces. The historical role of the Reform Club of Hong Kong and the Hong Kong Civic Association is largely forgotten and little-studied. This is the first academic treatment of these two earliest political parties in postwar Hong Kong. It aims to give a better understanding of the intricate relationship between the Colonial Government and the staff in London, the nature of colonial politics in early postwar Hong Kong, and the legacy of the Reform Club of Hong Kong and the Hong Kong Civic Association in today’s Hong Kong. / 一直以來，香港史的論著都認為政黨在一九八零年代後才興起，而香港人在一九九零年代開始才比較關心政治。這誤解可能建基於不同的理論：包括難民心態、行政吸納政治，以及傳統中國人性格等。通過戰後香港革新會及香港公民協會的歷史研究，我們可以對當時的政制發展有更清晰的了解。雖然政制發展在一九八零年代前並不顯著，但香港人並非政治冷感；其實政黨早在一九八零年代前已經開始有所發展。 / 香港革新會及香港公民協會並非一般所指的壓力團體，而是積極爭取政治，經濟及社會改革的政黨。作為政府與市民之間的橋樑，它們特別關注香港的城市發展、房屋政策、醫療保障、經濟發展、教育普及、治安以及小販問題。雖然兩個政黨不時批評政府的政策，但殖民地政府亦樂於利用它們作為與民溝通的橋樑以及平衡各方勢力。香港革新會及香港公民協會的歷史角色已漸被遺忘及忽視。這篇論文首開這兩個政黨學術研究之先河，希望通過其研究加深對殖民政府與宗主國的關係，戰後的殖民地性質、以及被遺忘的香港革新會及香港公民協會的了解。 / Tsang, Yik Man. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 336-357). / Abstracts also in Chinese. / Title from PDF title page (viewed on 30, September, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.

This investigation explored the feasibility of recently developed toughened cyanate ester networks as candidate materials for high performance composite matrix applications. The resin investigated was a Bisphenol-A cyanate ester toughened with hydroxy functionalized phenolphthalein based amorphous poly(arylene ether sulfone). The thermoplastic modified toughened networks exhibited improvement in the fracture toughness over the base cyanate ester networks without significant reductions in mechanical properties or glass transition temperature. Void free, unidirectional carbon fiber prepreg was successfully manufactured with the toughened cyanate resin using a solventless hot-melt technique. The resin mass fraction of the prepregs was between 31 and 35%. The carbon fiber, toughened cyanate ester prepreg was fabricated into composite panels for mechanical and physical testing. The cure cycle used to manufacture the composite laminates was developed with the aid of a process simulation model developed by Loos and Springer. In order to accurately simulate the resin curing and flow processes, the cure reaction kinetics and melt viscosity was characterized as a function of temperature and degree of cure and input into the simulation model. The model generated cure cycle was used in the manufacture 8-ply unidirectional and 16-ply quasi-isotropic composite laminates. The manufactured laminates were well consolidated to the specified fiber volume fraction between 59 and 60%. Photomicrographs showed that the laminates are void free, the fiber and resin distribution is uniform and fiber wet-out is very good. Mechanical tests were performed to measure the impact damage resistance and shear properties of the toughened cyanate ester resin composites. The results show improvements in impact damage resistance compared with the commonly used hot-melt epoxy resin composites. The influence of processing on performance was observed from the results of shear tests. Carbon fabric composite panels were manufactured by liquid molding processes (resin transfer molding and resin film infusion), with a series of four toughened cyanate ester resins generated by varying the concentration and the molecular weight of the toughener. The panels were subjected to physical, damage tolerance, and fracture toughness tests. The results of physical testing indicate consistently uniform quality, and the void content was found to be less than 2%. The toughened cyanate ester composites exhibited significantly improved impact damage resistance and tolerance compared with hot-melt epoxy systems. Marked increase in the mode II fracture toughness were observed with an increase in the concentration and the molecular weight of the toughener. / Ph. D.