A Simulation Model for Life Cycle Project Management

This paper puts forward a simulation model specifically designed for holistic evaluation of project functionality within a life cycle project management framework. The authors describe a methodology for development of the aforementioned tool, referred to as a dynamic simulation modeling system (DSMS). The DSMS is geared toward modeling of service and manufacturing processes with hierarchical and modular modeling methodology; however, the underlying philosophy can be adopted for modeling any generic system. The enhanced modeling features and logical division of large systems into small process components and their internal linkage are the key contributions of this work. The aim of this development is to apply the simulation technique in order to evaluate the overall project functionalities from the dynamic business perspective. A set of business objective functions (i.e., life cycle objective function [LCOF]) has been employed as a basis for decision making throughout the project's life. Object-oriented programming language with the object-oriented database technology facilitates the necessary model capability. A brief case study has been used to demonstrate and discuss the model capability.     

Effect of oxidation on the chemical nature and distribution of low-temperature pyrolysis products from bituminous coal

Two bituminous coals, a high volatile Eastern Canadian and a medium volatile Western Canadian, were used to investigate the effect of oxidation on yields and chemical composition of gases, liquids and chars produced during coal pyrolysis. Pyrolysis experiments were performed at 500 °C using the Fischer assay method. Mild oxidation of coals resulted in a decrease of liquid hydrocarbon yields. Further coal oxidation increased the proportion of aromatic carbon in liquid products as determined by n.m.r., and also increased the content of oxygen in liquid products. The content of oxygen in chars was markedly lower than in corresponding coals. An attempt is made to explain reactions occurring during oxidation and subsequent pyrolysis of coal on the basis of differences in chemical composition of gases, liquids and chars.     

Relational partnerships: the importance of communication,trust and confidence and joint risk management in achieving project success

The advantages of relational partnerships as an alternative project delivery mechanism to the traditional methods have yet to be realized by the wider construction industry. In relational partnerships, all parties work together as a cohesive team to achieve an agreed outcome. However, an accurate estimation of the underlying factors associated with the relationships of these parties and assessment of their impacts on partnering success are difficult to achieve. By identifying three major factors, communication, trust and confidence and joint risk management, this research unfolded the relational links between these factors and analysed the impacts in the context of the relational partnering success. Based on a questionnaire survey and the structural equation modelling technique, results identified communication as the single most influencing factor impacting on relational partnering success. While trust and confidence were found to be mutually inclusive for effective communication, it was found to have direct influence on developing capability for joint risk management within the partnering organizations. This finding diverges from the widely accepted view across the Australian construction industry that partnering is built on trust and confidence only and any risks associated in projects are best dealt with by means of joint responsibility without any problems.     

Analysis of pre‐qualification criteria in contractor selection and their impacts on project success

While construction industry practices are reasonably well developed, construction projects still witness widespread failures of many contractors due to varied reasons such as financial problems, poor management, over‐commitment and or conflicts and disputes associated with construction activities. Pre‐qualification of contractors is a common practice across projects, yet the investigation on the ability of the selected contractors in successful delivery of projects is not widespread. In an attempt to understand these pre‐emptive qualification criteria and their links in contractors’ performance in projects, a total of 43 influencing technical attributes were identified through a systematic research approach. The relative significance and impacts of the attributes have been determined based on a structured questionnaire survey in selected construction projects. By performing the factor analysis, a total of seven factors significant to contractors’ performance were extracted, namely (1) soundness of business and workforce; (2) planning and control; (3) quality management; (4) past performance; (5) risk management; (6) organizational capability; and (7) commitment and dedication. Multiple linear regression models reveal that technical expertise, past success, time in business, work methods and working capital significantly impact on contractors’ performance across time, cost and quality success. With a clear understanding of a contractor’s performance, these findings could potentially contribute to development of a company’s procedures or enhance existing knowledge in relation to the pre‐qualification practices in contractor selection in projects.     

Simple Scheduling Algorithms for Use with a Waveguide Grating Multiplexer Based Local Optical Network

As the need for greater bandwidth in local-area networks grows, wavelength-division multiplexing (WDM) is gathering attention as a viable successor to Gigabit Ethernet technologies. In this paper we introduce a new WDM optical LAN architecture based on the waveguide grating multiplexer (WGM) rather than the traditional passive star coupler (PSC). An N-port WGM allows N ² × N ² connectivity via only N physical wavelengths, due to its inherent space-division multiplexing property. Wavelength-routed networks based on the WGM promise to be significant components of future LAN and WAN technologies not only because of their efficient use of wavelengths, but also because they have been implemented as integrated devices. We propose simple, low-complexity TDM schedules for interconnecting MN nodes (M nodes per port) with a WGM in a local environment. Each node is equipped with a single tunable transmitter and a single tunable receiver (both of which can access all N wavelengths). Various transmitter and receiver tuning latencies are considered. We show that, for negligible tuning latencies, aggregate network throughput approaching min(MN, N ²) can be achieved, and for tuning latencies on the order of a packet length or more, throughput on the order of N can be achieved. Since these performance metrics are vastly superior to that of an equivalent PSC-based system (whose maximum throughput is limited by the number of wavelengths, N), we propose that the WGM be considered as an alternative to the PSC for enabling WDM LANs and multiprocessor interconnects.     

Local drug delivery system for the treatment of osteomyelitis: In vitro evaluation

Local antimicrobial delivery is a potential area of research conceptualized to provide alternative and better methods of treatment for cases, as osteomyelitis where avascular zones prevent the delivery of drugs from conventional routes of administration. Drug-loaded polymers and calcium phosphates as hydroxyapatites have been tried earlier. Bioactive glasses are bone-filling materials used for space management in orthopedic and dental surgery. A new bioactive glass (SSS2) was synthesized and fabricated into porous scaffold with a view to provide prolonged local delivery of gatifloxacin and fluconazole as suitable for the treatment of osteomyelitis. The new SSS2 was characterized by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses. In addition, the bioactivity of the SSS2 glass and resulting scaffold was examined by in vitro acellular method and ascertained by FTIR and XRD. The pore size distribution was analysed by mercury intrusion porosimetry and the release of drugs from scaffolds were studied in vitro. The glass and the resulting scaffolds were bioactive indicating that they can bond with bone in vivo. The scaffolds were porous with pores predominantly in the range of 10-60 μm, released the drugs effectively for 6 weeks and deemed suitable for local delivery of drugs to treat osteomyelitis.     

Predictive model and process parameters optimization of Nd:YAG laser micro-turning of ceramics

The present work highlights laser micro-turning operation of 10-mm diameter cylindrical-shaped alumina (Al₂O₃) ceramic using pulsed Nd:YAG laser. The paper also addresses development of mathematical models for correlating the various micro-machining parameters such as laser beam average power, pulse frequency, workpiece rotational speed, assist air pressure, and Y feed rate with the response criteria such as surface roughness and deviation in turned depth for achieving desired surface quality as well as dimensional accuracy during micro-turning operation using Nd:YAG laser system. Response surface methodology-based design of experiments has been adopted for the experimentation. This investigation also highlights the various test results that confirm the validity and correctiveness of the developed mathematical models through analysis of variance test. The test results were analyzed through various response surface plots to study the effect of the process parameters on the aforementioned responses. The results of validation experimentation show a good agreement for the developed empirical models. Sensitivity analyses of the developed models have been done to find out the variation in the output with respect to variations in the significant input process parameters. Moreover, multi-performance optimization has been done to find out the optimal parametric setting for achieving the desired process performances. Analysis also has been made based on scanning electron microscopy micrographs of the laser micro-turned surface achieved during machining at multi-criteria optimization setting.     

Chitosan‐coated alginate–polyvinyl alcohol beads for encapsulation of silicone oil containing pyrene: a novel method for biodegradation of polycyclic aromatic hydrocarbons

BACKGROUND: Polycyclic aromatic hydrocarbons (PAHs) are potential hazards in the environment owing to their toxic, carcinogenic and recalcitrant nature. Biodegradation of these compounds, although effective compared with other treatment techniques, is problematic owing to its low aqueous solubility and negligible bioavailability. The present study reports a novel method for biodegradation of PAHs using an encapsulated form of the pollutant in chitosan‐coated alginate–polyvinyl alcohol (PVA) beads. RESULTS: A suitable combination of 3% (w/v) PVA, 100 g L^?1 non‐ionic surfactant Brij 30 and 0.3 silicone oil fraction in the formulation was found to be optimal in the preparation of stable emulsion. The emulsion obtained was admixed with alginate (3% w/v) to prepare suitably sized microspheres by an emulsion gelation technique, which were later coated with chitosan to yield a maximum pyrene encapsulation efficiency of 90.7%. Pyrene in silicone oil at concentration as high as 2 g L^?1, when delivered through the chitosan coated alginate–PVA beads, was completely degraded by Mycobacterium frederiksbergense within 10 days without any significant lag phase. CONCLUSION: Using chitosan‐coated alginate–PVA beads sustained release of pyrene and subsequent biodegradation by M. frederiksbergense were achieved. Using the present system, complete degradation of pyrene was attained even at its very high initial concentration and within a short time period. Further advantage offered by this system seems to be negligible toxic effect of pyrene and solvents on the degrading microorganisms since these were in an encapsulated form and were not in direct contact with the organism. Copyright © 2010 Society of Chemical Industry     

Effect of doping in hydroxyapatite as coating material on biomedical implants by plasma spraying method: A review

Hydroxyapatite (HAp) is still one of the most widely used bioactive coating material to metallic implant in orthopedic fields because of its good biocompatibility, chemical and structural resemblance to natural bone, osteo-conductivity, coupled with quicker implant fixation and strong bonding between living bone with implants. Many techniques are used to deposit HAp as coating material on metallic implants among which plasma spray coating stands out as this process is cost effective, reliable, and protects surface of metal from wear and corrosion. Although, HAp is a smart choice as implant coating material, however, its medical application has been restricted because of the unfavorable mechanical properties like brittleness, weak fracture toughness and poor tensile strength. Further, HAp coated implants suffer from longer time period for remodeling, slow osseointegration rate and lack of antimicrobial effects/properties. Different methodologies have been adopted as surface modification techniques to increase mechanical as well as biological properties of HAp. Among those approaches use of dopants in HAp is a very efficient way for modification of properties. Therefore, aim of this review paper is to assemble information related to HAp coating by plasma spray technique on implants and discuss their advantages and limitations. The article also reports how addition of various doping ions into HAp can overcome these limitations by effecting structural, compositional, mechanical properties of HAp. Finally, it reports how the single, binary and multi ion dopants incorporation in the HAp structure can affect the properties which ultimately affect implant functionality when coated by plasma spraying method.