The Critical Path Method (CPM) is a widely used tool throughout the construction industry. Since its creation, the use and application of the Critical Path Method has grown tremendously. Up to date, three studies have been performed on how Engineering News Record's (ENR) Top 400 Contractor use CPM. The first study was performed by Edward Davis in 1974 and the second was performed by Amir Tavakoli and Roger Riachi in 1990. This paper is a summary of the third survey, which took place in 2003. The results from the three studies indicate that CPM use by the Top 400 Contractors is growing and the areas of use are expanding. The number one use of CPM throughout the years is detailed planning before the start of construction. Periodic control during construction is another large area of CPM use and has been a large area of growth due to the advances in technology, which make updating a schedule during construction easier and faster than was possible with a mainframe computer in the past. Another area of CPM growth is estimating and bidding for several reasons: use in this area has jumped from 19% to 54% in the past 30 years. An area of concern lately in CPM is the use of precedence diagramming instead of arrow diagramming. Despite the debate, the responding companies found precedence diagrams easier to read, provide more flexibility, and allow for easier use of "smart" relationships (i.e. start-start). / Master of Science

Sustainable Built Environments Senior Capstone Project / The idea of using nature, as a design model in building construction is not a new one; this innovative technique is known as biomimicry in architecture. This study focuses on biomimicry and its application in three buildings; The University of Arizona’s new Environmental and Natural Resource Phase 2 (ENR2) building; Architect Mick Pearce’s Eastgate Centre in Harare Zimbabwe; and Council House 2 (CH2) in Melbourne Australia. The research in this paper is centered around the ENR2 building, it examines the extent to which biomimcry is applied in terms of aesthetics and performance, by comparing it to the Eastgate Centre and CH2 buildings.

<p>Anknytningsteorin handlar i grunden om barns relationer till sina primära vårdnadsgivare, och har också kommit att bilda ramverk för studier kring vuxna kärleksrelationer. ”Experiences of Close Relationships” (ECR) är ett självskattningsinstrument som mäter vuxenanknytning, och som används i forskningen sedan 1998. Denna studies första syfte var att undersöka den svenska versionen av detta instrument: ”Erfarenheter av Nära Relationer” (ENR) och dess psykometriska egenskaper. Dess andra syfte var att titta på skillnader i svarsmönster hos olika grupper i urvalet, bestående av 313 studenter vid Stockholms Universitet. ENR verkade ha liknande psykometriska egenskaper beträffande faktorstruktur som förlagan ECR. Det fanns också visst stöd för reliabilitet och validitet. Vidare uppmättes skillnader i svarsmönster mellan män och kvinnor, mellan olika åldersgrupper, mellan grupper med olika relationsstatus och mellan respondenter med och utan barn. ENR befanns således fungera tillfredsställande i det aktuella urvalet, och bedömdes därför som lovande beträffande fortsatta studier i svenska populationer.</p>

Anknytningsteorin handlar i grunden om barns relationer till sina primära vårdnadsgivare, och har också kommit att bilda ramverk för studier kring vuxna kärleksrelationer. ”Experiences of Close Relationships” (ECR) är ett självskattningsinstrument som mäter vuxenanknytning, och som används i forskningen sedan 1998. Denna studies första syfte var att undersöka den svenska versionen av detta instrument: ”Erfarenheter av Nära Relationer” (ENR) och dess psykometriska egenskaper. Dess andra syfte var att titta på skillnader i svarsmönster hos olika grupper i urvalet, bestående av 313 studenter vid Stockholms Universitet. ENR verkade ha liknande psykometriska egenskaper beträffande faktorstruktur som förlagan ECR. Det fanns också visst stöd för reliabilitet och validitet. Vidare uppmättes skillnader i svarsmönster mellan män och kvinnor, mellan olika åldersgrupper, mellan grupper med olika relationsstatus och mellan respondenter med och utan barn. ENR befanns således fungera tillfredsställande i det aktuella urvalet, och bedömdes därför som lovande beträffande fortsatta studier i svenska populationer.

Competitive Bidding, Competitive Sealed Proposal, construction management agency, construction management at risk, Design-Build, Design-Build-Bridging, and job order contracting are seven project delivery methods that are commonly used in the state of Texas today. This paper empirically compares the cost, schedule, and change order management performance of these project delivery methods in 2009 Engineering News Record (ENR) Best Construction Projects in Texas, using the data collected from the projects representative of the population. Also information is collected on lessons learned from these projects. The thesis included development of survey instrument, getting approval from Institutional Review Board (IRB), data collection from the industry, statistical analysis and inferences. Based on the data collected, project performances were measured in terms of five identified variables and then plotted in the form of probability distribution curves to understand the characteristics of the target population. Then, the results were grouped into six categories based on project delivery methods used and compared to understand their impacts on these projects. Findings revealed predominant usage of CM at Risk PDM, and better cost and schedule performance of CM at Risk, Design-Build, and Owner customized PDM. Detailed performance metrics, results, interpretations and conclusions are presented.

Optimisation d’un isolateur coplanaire à déplacement de champ et ondes magnétostatiques opérant en bande X. Résumé en français non fourni / Optimization of an isolator coplanar field displacement and waves magnetostatic operating in X-band. English abstract not supplied

Biocomposites exhibit properties like many petrochemical-based polymers composites. They have the potentials be used in the automotive and decking industries and as biodegradable packaging. However, the high cost as well as, poor mechanical and thermal properties have restricted their widespread use. There are a number of technical issues that need to be addressed before bio-composites can be widely used. In this research Polylactic acid (PLA) composites, reinforced with natural fibres (wood, flax) and mineral fillers (talc) were investigated. The thermal and mechanical properties of the composites were studied by means of Differential Scanning Calorimetry (DSC), Tensile Testing and Dynamic Mechanical Analysis (DMA), while morphology and crystallization processes of the composites were studied by hot stage optical microscopy. The experimental results are also compared with different theoretical models of the response of the composites. PLA / wood composites were developed by mixing PLA with wood in different ratios using a melt compounding process. PLA/wood (90/10. 80/20, 60/40), PLA/wood/copolymers (85/10/05, 80/10/10, 75/20/05, 70/20/10, 55/40/05, 50/40/10) and PLA/wood/coupling agent (80/20/silane coating) were the three different composite systems that were developed. Adding increasing amount of wood into the PLA, the thermal properties remain unchanged but the mechanical properties increased significantly, bringing a stiffening effect to the composites. Tensile modulus increased from 4.1± 0.6 to 9.8 ± 1.2 (GPa) as the wood content increased from 0 to 40 (wt %), but the tensile strength at break reduced from 43.8 ± 3.1 to 31.8 ± 2.8 MPa. The experimental results of the PLA-wood composites were modelled according to the Halpin-Tsai equation. The addition of copolymer affected the thermal properties considerably by decreasing the glass transition temperature of the composite. The glass transition temperature dropped from 54 ± 0.7 (0C) to 48 ± 0.36 (0C) when the content of copolymer was increased from 0 to 10 (wt %). The cold crystallization temperature also decreased from 127 ± 1.41 (0C) to 103 ± 2.58 (0C) when the copolymer was incorporated into the PLA/wood composites. The significant aspect was the occurrence of a double peak in the melting endotherm. The degree of crystallinity also increased from 2 ± 0.83 (%) to 11 ± 1.23 (%) when the amount of copolymer was increased to 10 (wt %). PLA, flax and expoidizied natural rubber (ENR) composites were also developed using a melt compounding process. The mechanical properties were affected significantly when the flax fibres were mixed with PLA in the ratios of 10, 20 and 30 (wt %). Addition of flax fibres increased the elastic modulus significantly but reduced the tensile strength and strain at break. To improve the toughness of the PLA- Flax composites, ENR was incorporated into the PLA- Flax composites. In order to balance the modulus of the reinforcement and the matrix, the PLA- Flax and ENR composites were annealed above the glass transition temperature and the degree of crystallinity increased from 2 to 35 (%). The integral blending of PLA, Flax and ENR did not affect the brittle fracture but introducing a masterbatch of flax fibres and ENR into the PLA matrix during melt processing had a considerable effect on the fracture behaviour of the composites. The elastic modulus of the composites decreased due to the elastomeric content in the composites and there was an increase in elongation-to-break. The effect of talc on the crystallinity and mechanical properties of a series of polylactic acid (PLA) / talc composites was investigated. PLA talc composites were developed by incorporating different types of the talc into the PLA in the ratios of 10, 20 and 30 (wt %). The composites were prepared by melt blending followed by compression moulding. It was found that talc acted as a nucleating agent and increased the crystallinity of the PLA from 2% to 25%. There was significant improvement in Young s modulus of the composites with increasing talc addition and these results were found to fit the Halpin Tsai model. Thermo-mechanical tests confirmed that the combination of increased crystallinity and storage modulus leads to improvement in the heat distortion properties.

L'objectif de ces travaux de thèse était de concevoir et de développer un outil de simulation et d'optimisation multicritères de centrales couplant des sources d'énergies renouvelables (EnR) et des moyens de stockage. L'optimisation porte sur le dimensionnement de l'installation (taille des unités de production EnR et de stockage) et sur la ou les stratégies de gestion de la centrale EnR-stockage selon des critères technico-économiques évalués par l'outil. L'originalité de l'outil développé réside dans la modularité de définition de l'architecture EnR-stockage, dans la prise en compte de plusieurs niveaux de modélisation (échelle et précision) des différents composants du système et dans l'intégration du vieillissement. L'outil développé est également illustré sur des cas d'études afin d'apprécier sa pertinence.

Piles have been used since prehistoric times in areas with weak subsurface conditions either to reinforce existing ground, create new ground for habitation or trade, and support bridges and buildings. Originally piles were composed of timber and driven with drop hammers using very heavy ram weights. As technology improved so did the materials that piles are composed of as well as the equipment itself. Currently, piling is a multibillion dollar a year industry, thus the need to develop more accurate prediction methods can potentially represent a significant savings in cost, material, and man power. Multiple predictive methods have been developed to estimate developed pile capacity. These range from static theoretical formulae based on geotechnical investigation prior to pile driving even occurring using specific pile and hammer types to semi empirically based dynamic formulae used during actual driving operations to more recently developed computer modeling and signal matching programs which are calibrated with site condition during initial geotechnical investigations or test piling to full scale static load tests where piles are loaded to some predetermined value or failure condition. In this thesis, dynamic formulae are used to predict pile capacity from those installed by drop and diesel hammers and are compared to the results from pile load tests, which are taken as the true measure of developed bearing capacity. The dynamic formulae examined are the Engineering News Record (ENR), Gates, Federal Highway Administration (FHWA) modified Gates, Hiley, and Ontario Ministry of Transportation (MTO) modified Hiley formulae. Methods of investigation include calculating pile capacities from the formulae as they are, omitting the factors of safety, revising the formulae with averaged coefficients and conducting multi regression analysis to solve for one or two coefficients simultaneously and revising the dynamic formula to determine if more accurate bearing capacity prediction are possible. To objectively determine which formulae provide the most accurate bearing capacities, the predicted capacities will be compared to results obtained from static pile load tests and simple statistics on the resulting data set will be calculated including regression analysis, standard deviations, coefficients of variation, coefficients of determination, and correlation values.

Piles have been used since prehistoric times in areas with weak subsurface conditions either to reinforce existing ground, create new ground for habitation or trade, and support bridges and buildings. Originally piles were composed of timber and driven with drop hammers using very heavy ram weights. As technology improved so did the materials that piles are composed of as well as the equipment itself. Currently, piling is a multibillion dollar a year industry, thus the need to develop more accurate prediction methods can potentially represent a significant savings in cost, material, and man power. Multiple predictive methods have been developed to estimate developed pile capacity. These range from static theoretical formulae based on geotechnical investigation prior to pile driving even occurring using specific pile and hammer types to semi empirically based dynamic formulae used during actual driving operations to more recently developed computer modeling and signal matching programs which are calibrated with site condition during initial geotechnical investigations or test piling to full scale static load tests where piles are loaded to some predetermined value or failure condition. In this thesis, dynamic formulae are used to predict pile capacity from those installed by drop and diesel hammers and are compared to the results from pile load tests, which are taken as the true measure of developed bearing capacity. The dynamic formulae examined are the Engineering News Record (ENR), Gates, Federal Highway Administration (FHWA) modified Gates, Hiley, and Ontario Ministry of Transportation (MTO) modified Hiley formulae. Methods of investigation include calculating pile capacities from the formulae as they are, omitting the factors of safety, revising the formulae with averaged coefficients and conducting multi regression analysis to solve for one or two coefficients simultaneously and revising the dynamic formula to determine if more accurate bearing capacity prediction are possible. To objectively determine which formulae provide the most accurate bearing capacities, the predicted capacities will be compared to results obtained from static pile load tests and simple statistics on the resulting data set will be calculated including regression analysis, standard deviations, coefficients of variation, coefficients of determination, and correlation values.