Construction Projects involve a large number of participants with often overlapping activities. Schedules play a key role in coordination of these activities. A general contractor or a construction manager is usually responsible for coordination and has a master schedule that covers the scope of the entire project. The individual participants have different project management objectives and build schedules for their scope of work using different breakdown structures, different levels of detail, different scheduling software and different naming conventions. Existing scheduling techniques and software provide a robust set of constructs to generate these individual schedules. However, coordination of these schedules is a manual iterative task not adequately supported by existing theories and software tools. The primary aim of this research was to provide a framework to enable analysis across distributed heterogeneous schedules. The framework presented in this dissertation, schedule mappings, provides a set of constructs to dynamically link individual participant schedules to the master schedule. The schedule mappings approach uses the linked schedules to facilitate schedule coordination by rapid identification of scheduling conflicts. This identification enables rapid initial coordination of schedules and supports assessment of scheduling alternatives in response to a schedule change. A software tool was developed using Microsoft Visual Basic[trademark] programming language as a Shared Addin for Microsoft Project[trademark]. This dissertation contributes to state of the art of scheduling by providing a framework for reasoning across multiple schedules. From an industry perspective, this research makes a contribution by formalizing identification of scheduling conflicts. The formalisms and the tool should help industry professionals in rapid assessment of scheduling alternatives. The tool enabled the use of the schedule mappings approach by industry professionals and was used for validation. The approach was validated in a two step process and was shown to be beneficial. / text

This dissertation investigates several business cycle relationships when economic agents are heterogeneous. The particular focus is on the interactions between the cross-section of agents and the aggregate state of the economy. The first chapter shows that, when occasionally binding capacity constraints limit the production of heterogeneous firms, demand shocks can endogenously generate a number of important business cycle regularities: recessions are deeper than booms are high, firm-level volatility is countercyclical, the aggregate Solow residual is procyclical and the fiscal multiplier is countercyclical. A baseline calibration of a basic New Keynesian DSGE model with capacity constraints shows that this mechanism can explain more than a quarter of the empirically observed asymmetry in output, and matches the cyclicality of firm-level profitability dispersion and of the measured Solow residual. The model implies fluctuations in the fiscal multiplier of around 0.12 between expansions and recessions. Chapter two takes a different approach to firm level uncertainty, exploring how recessions can cause an endogenous rise in firm risk. If heterogeneous firms face real and financial frictions, then a shock to the mean of aggregate productivity endogenously leads to countercyclical profitability risk through firms' heterogeneous responses in price setting. Additionally, the mechanism endogenously generates countercyclical credit spreads and credit spread dispersion. The model explains a large share of the observed fluctuations in profitability dispersion (69%) and in credit spreads (40%) through fluctuations in aggregate TFP holding productivity risk constant. This suggests that the scope for uncertainty shocks to explain recessions may be smaller than previously thought. The third chapter focuses on distributional effects of oil price shocks on the household side. In the model, household behavior replicates two patterns found in household-level data which show that gas consumption increases with income, but on the intensive margin gasoline consumption as a share of the household's budget decreases with income. The model includes gas consumption in household utility on top of a fixed minimum level of gas consumption. Calibrated simulations suggest that a shock to the gas price is almost twice as costly for relatively poor households than for relatively rich households. / text

Multilateral well technology has been widely used in the world oil fields. There still has technical limitation of these kinds of well structure. This thesis presents a new multilateral well architecture which is more flexible and economical. The performance of new multilateral well in heterogeneous reservoirs is studied, and that is compared with vertical well architecture also. In order to study the productivity of new multilateral wells, we use a numerical simulation method to set up heterogeneous reservoir models. The three reservoir models included anisotropic permeability, shale multi-layer, and flow units. Under a pseudo-steady-state, the productivities of horizontal laterals and deviated laterals are calculated and compared. We find that new multilateral well architecture has good performance in heterogeneous reservoir. The heterogeneous properties of reservoirs influence the productivity of horizontal laterals more than deviated laterals. The shale multi-layer and flow units that dominate the fluid flow in reservoirs are important for reservoir characterization.

Squeezing ground in tunnelling is a unique method of failure, typically occurring in ductile rock at depth. To accommodate this mechanism of failure, liners have been designed such that they reduce in circumference as the support takes on initial load. Technological development in this area is all the more important for tunnels mined in heterogeneous rockmasses. Currently, the state of practice is to design support based on a normalised average of the strength parameters of the rock units present in the tunnel face. Under many configurations of heterogeneity, this approach is perfectly valid, however there are styles and magnitudes of heterogeneity that require deeper analysis. The purpose of this study is to introduce an empirical relationship between liner response in heterogeneous rockmasses and liner response in the homogenised equivalent. A suite of parameters that define heterogeneity were numerically modelled, using finite element analysis, such that a comprehensive set of the various permutations was evaluated. The three styles of heterogeneity that were modelled were chaotic structure, folded structure and laminar structure, these represent common and discrete structures found in alpine regions. Laminar structure was considered at three orientations, and all structures were considered under hydrostatic and differential stress regimes. Granularity, or scale, and contrast ratio of units were also varied. These data were analysed with respect to mean axial thrust, range of axial thrust and range of moment on the liner. Liner response analysis was also conducted on the case study of St. Martin-la-Porte, an adit to the Lyon-Turin Ferroviaire base tunnel in southern France. This adit has been excavated in a highly variable, heterogeneous rockmass and provides realistic examples of the nature of heterogeneity present in current tunnelling projects. Ultimately, three equations were developed to provide preliminary predictions of heterogeneous axial thrust and moment variability from the analysis of homogeneous equivalents. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2011-01-14 19:16:42.908

TiO2 supported MoO3 catalysts were prepared by aqueous impregnation of low area anatase (10 m2g-1) with solutions of (NH4)6Mo7024,4H20 (MT/C series), and H2[Mo03(C204)].H20 (MOT /C series), Three series of CoOx/Ti02 catalysts were fabricated by aqueous impregnation of the same support with solutions of Co(N03)2,6H20 (CT/C series), and Co(CH3COO)2.4H20 (CAT/C series), and by homogeneous precipitation using Co(N03)2,6H20 (CT/HP series), CoO and Mo03 were deposited on Degussa P-25 (55 m2g-1) by aqueous impregnation using (NH4)6Mo7024,4H20 and Co(N03)2,6H20 in three ways: ( i) CoO impregnated first, Mo03 second (CMT series); (ii) Mo03 impregnated first, CoO second (MCT series); and (iii) CoO and Mo03 together (CMTg series). The catalysts were characterized by laser Raman spectroscopy (LRS) , temperature-programmed reduction (TPR) , X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM), Monolayer coverage by XPS was independent of the precursor for the MoOx/Ti02 catalysts, but a function of the method of preparat ion and the precursor for the CoOx /Ti02 catalysts. XPS results for the CMTg series differed from those for the CMT and MCT series, suggesting different surface species had been formed by varying the mode of impregnation, Phase diagrams relating semiquantitatively to the oxide contents are presented. 2-propanol decomposition was studied to probe the acid-base properties of the catalysts, Ti02 and Mo03 exhibi ted dehydration activity, whereas CoO showed dehydrogenation activity, All the supported catalysts gave activation energies for dehydration higher than dehydrogenation. In the sub-monolayer region, the catalytic activity for dehydration was in the order: MCT > CMTg > CMT > MT/C > CT/C, while the selectivity remained almost unchanged, In the monolayer region, the activity was: MT/C > CMT > CMTg > MCT > CT/C and the selectivity increased compared with the sub-monolayer region. In the four-monolayer reg ion, the activity decreased compared with the sub-monolayer and monolayer regions, but the selectivity increased relative to the previous two regimes. "Compensation effect 0, plots revealed different types of active centres responsible for dehydration and dehydrogenation processes in the MoOx /Ti02 and CoO-Mo03/Ti02 catalysts, while active centres were almost identical with the CoOx /Ti02 system.

Biodiesel is a renewable and biodegradable alternative green fuel for petroleum-based diesel. The major obstacle for the production of biodiesel at an industrial scale is the high production cost, which is related to the relative high price of the conventional ???1st generation feedstocks??? (refined vegetable oils) used. This problem can be addressed by using low cost feedstocks such as waste oils and fats. However, these feedstocks contain high amounts of free fatty acids (FFA) which cannot be used for the production of biodiesel using a traditional homogeneous alkali-catalyzed transesterification process. Furthermore, there is a great need to develop a green process which can be used for multiple feedstocks. This shows the universal ability of the process to be adopted as per availability of local feedstock. In this study, a single-step second generation heterogeneous-catalyzed process is developed to produce biodiesel from multi-feedstocks. Due to an increase in the commercial use of biodiesel and biodiesel blends, both ASTM D6751 and EN 14214 include the acid number (AN) as an important quality parameter. Currently, ASTM D974 and D664 analytical methods for acid number analysis of biodiesel are time consuming, expensive, and environmentally not friendly. Therefore, ASTM D974 has been modified and a green analytical method has been developed. This extensive study has demonstrated that this new method is a reliable method for the determination of AN and could be used for establishing the specifications of AN for biodiesel and biodiesel blends ranging from B1 to B20 in quality standards. The ASTM reference standard method D664, has major problems such as the use of excess toxic solvents, large sample size, mediocre reproducibility, tedious process for cleaning electrodes, and relatively long analysis time. Therefore, a new proposed method based on green chemistry approaches, has been developed to determine the acid number of biodiesel and biodiesel blends using small sample size and reduced toxic titration solvent. This proposed green analytical method could be used for the determination of AN of biodiesel and biodiesel blends in R&D as well as industrial quality control laboratories as a simple, time-efficient, cost effective and environmentally friendly method.

No description available.

Diss. Stockholm : Handelshögsk., 2001.

Thesis (Master)--İzmir Institute of Technology, İzmir, 2006. / Keywords:Suzuki reactions, palladium, NaYzeolite, heterogeneous catalyst, C-C coupling. Includes bibliographical references (leaves. 71-81).

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.