The Dynamic Multi-objective Multi-vehicle Covering Tour Problem

This work introduces a new routing problem called the Dynamic Multi-Objective Multi-vehicle Covering Tour Problem (DMOMCTP). The DMOMCTPs is a combinatorial optimization problem that represents the problem of routing multiple vehicles to survey an area in which unpredictable target nodes may appear during execution. The formulation includes multiple objectives that include minimizing the cost of the combined tour cost, minimizing the longest tour cost, minimizing the distance to nodes to be covered and maximizing the distance to hazardous nodes. This study adapts several existing algorithms to the problem with several operator and solution encoding variations. The efficacy of this set of solvers is measured against six problem instances created from existing Traveling Salesman Problem instances which represent several real countries. The results indicate that repair operators, variable length solution encodings and variable-length operators obtain a better approximation of the true Pareto front

Evaluation of the effect of air pollution on human health in Kuwait.

Even before the 1990 war the populations of some areas of Kuwait was subject to severe atmospheric pollution. However, little was known about the effect of this pollution on health and on the use of health care. Three areas in Kuwait were chosen for study which were demographically similar and lay at a different distances to the north (i.e. usually downwind) of the industrial area. Plant in this area emits hydrogen sulphide, sulphur dioxide, hydrocarbons, nitrogen oxides, ammonia and carbon monoxide among other pollutants. A special survey was carried out to gather information on demographic, health and lifestyle factors including age, sex, place of residence, smoking, physical symptoms, psychological effects, life satisfaction, environmental problems, experience of air pollution and use of health care. A random sample of 136 households (1140 persons) was chosen from the three areas and studied over the period from lst February 1988 to 31st January 1989. Data on levels of pollution concentrations and meteorological conditions were also collected over the same period for each area studied. Data on use of health care were available from the health centres in the three areas studied and also from the population survey.The demographic similarity of the three areas studied was generally confirmed by the data from population survey. The relationships involved were examined for different age groups using cross tabulation, time series analysis and regression analysis. There were clear gradients with increased distance from the industrial area in levels of pollution, levels of selfreported physical and psychological symptoms and in the use of health care. Of the individual pollutants it appeared that carbon monoxide levels were most closely correlated with levels of symptoms. For those aged less than 18, the link to CO was closest for respiratory symptoms, while for those aged 18 to 64 the link was with headache. The use of primary care is more closely linked to H2S although this relationship is relatively weak. Consider the relationship between levels of pollution in the three areas studied and Kuwait City and the levels of pollution in Shuaiba area taking meteorological conditions into account. The purpose of this was to allow for estimates of the effect of pollution reduction in Shuaiba on the health of population elsewhere in the country. However, no way was and of making such estimates with sufficient prison. This analysis confirmed a number of recommendations that have been made by others

NASA Tech Briefs, August 2002

Topics include: a technology focus on computers, electronic components and systems, software, materials, mechanics, machinery/automation, manufacturing, physical sciences, information sciences, book and reports, and Motion control Tech Briefs

Cationic Oligomeric Surfactants: Novel Synthesis and Characterization

Oligomeric surfactants, sometimes referred to as gemini surfactants, consist of two or more amphiphilic ‘monomer’ units linked together by spacer groups. The chemical identity of the spacer group is unconstrained, and it joins the individual units at or near the hydrophilic headgroups. Oligomeric surfactants display a range of interesting properties, including very low critical micelle concentrations, high surface activity and unusual rheology and self-assembly. Consequently they have many potential applications, both scientific and industrial. Until now, their use has been limited by the cost of their synthesis, which in some cases involve long and difficult procedures. This project developed from the idea that a synthesis based on polymerization could prove a useful and versatile method for producing these surfactants. The chemical starting point for this project was a series of polymerizable surfactants (‘surfmers’), upon which polymerization was performed. Two families of surfmers were investigated, both cationic and based on methacrylate and vinylpyridinium moieties respectively. The physical behaviour of these surfactants – a number of which are new – was investigated using standard techniques; these included the determination of the critical micelle concentration, characterization of phase behaviour, neutron scattering and surface adsorption. In producing oligomers, the initial focus was on free-radical polymerization, with control of molecular weight to be achieved by chain-transfer techniques. Due largely to analysis problems, this work proved unsuccessful. In its place a new reaction, not based on conventional polymerization methods, has been developed. The vinylpyridinium surfmers mentioned above readily undergo addition across the double bond to produce alkyl ring substituents. Under basic conditions, these alkylpyridiniums undergo an elimination/addition reaction in which they link together to form oligomers. This reaction can be started or stopped by raising or lowering the pH of the reaction solution, and has been performed in both organic and aqueous solutions. It is referred to in this thesis as LELA(Linkage by ELimination/Addition). The LELA reaction was used to produce mixtures of oligomers, the phase behaviour and surface adsorption of which were examined. Small-angle neutron scattering was used to monitor the reaction in real time and identify changes in self-assembly as the average oligomer length increased. Progress was also made towards a chromatographic protocol that would allow mixtures to be separated into their components and the pure oligomers to be studied. Finally, some of the compounds studied display interesting pH-dependent chromophoric properties which were also found to occur with other simple alkylpyridinium species. They are tentatively ascribed to inter- and intramolecular charge-transfer complexes, and evidence towards this conclusion was collected and is presented along with relevant calculations

Cationic Oligomeric Surfactants: Novel Synthesis and Characterization

Oligomeric surfactants, sometimes referred to as gemini surfactants, consist of two or more amphiphilic ‘monomer’ units linked together by spacer groups. The chemical identity of the spacer group is unconstrained, and it joins the individual units at or near the hydrophilic headgroups. Oligomeric surfactants display a range of interesting properties, including very low critical micelle concentrations, high surface activity and unusual rheology and self-assembly. Consequently they have many potential applications, both scientific and industrial. Until now, their use has been limited by the cost of their synthesis, which in some cases involve long and difficult procedures. This project developed from the idea that a synthesis based on polymerization could prove a useful and versatile method for producing these surfactants. The chemical starting point for this project was a series of polymerizable surfactants (‘surfmers’), upon which polymerization was performed. Two families of surfmers were investigated, both cationic and based on methacrylate and vinylpyridinium moieties respectively. The physical behaviour of these surfactants – a number of which are new – was investigated using standard techniques; these included the determination of the critical micelle concentration, characterization of phase behaviour, neutron scattering and surface adsorption. In producing oligomers, the initial focus was on free-radical polymerization, with control of molecular weight to be achieved by chain-transfer techniques. Due largely to analysis problems, this work proved unsuccessful. In its place a new reaction, not based on conventional polymerization methods, has been developed. The vinylpyridinium surfmers mentioned above readily undergo addition across the double bond to produce alkyl ring substituents. Under basic conditions, these alkylpyridiniums undergo an elimination/addition reaction in which they link together to form oligomers. This reaction can be started or stopped by raising or lowering the pH of the reaction solution, and has been performed in both organic and aqueous solutions. It is referred to in this thesis as LELA(Linkage by ELimination/Addition). The LELA reaction was used to produce mixtures of oligomers, the phase behaviour and surface adsorption of which were examined. Small-angle neutron scattering was used to monitor the reaction in real time and identify changes in self-assembly as the average oligomer length increased. Progress was also made towards a chromatographic protocol that would allow mixtures to be separated into their components and the pure oligomers to be studied. Finally, some of the compounds studied display interesting pH-dependent chromophoric properties which were also found to occur with other simple alkylpyridinium species. They are tentatively ascribed to inter- and intramolecular charge-transfer complexes, and evidence towards this conclusion was collected and is presented along with relevant calculations

Electric Vehicle Efficient Power and Propulsion Systems

Vehicle electrification has been identified as one of the main technology trends in this second decade of the 21st century. Nearly 10% of global car sales in 2021 were electric, and this figure would be 50% by 2030 to reduce the oil import dependency and transport emissions in line with countries’ climate goals. This book addresses the efficient power and propulsion systems which cover essential topics for research and development on EVs, HEVs and fuel cell electric vehicles (FCEV), including: Energy storage systems (battery, fuel cell, supercapacitors, and their hybrid systems); Power electronics devices and converters; Electric machine drive control, optimization, and design; Energy system advanced management methods Primarily intended for professionals and advanced students who are working on EV/HEV/FCEV power and propulsion systems, this edited book surveys state of the art novel control/optimization techniques for different components, as well as for vehicle as a whole system. New readers may also find valuable information on the structure and methodologies in such an interdisciplinary field. Contributed by experienced authors from different research laboratory around the world, these 11 chapters provide balanced materials from theorical background to methodologies and practical implementation to deal with various issues of this challenging technology. This reprint encourages researchers working in this field to stay actualized on the latest developments on electric vehicle efficient power and propulsion systems, for road and rail, both manned and unmanned vehicles

Intelligent planning and control of multi-assembly systems.

The global trend towards cost minimisation in manufacturing has intensified during the last two decades. Cost reduction can be achieved either, directly, through elimination of waste, or indirectly, through optimisation of production processes and generating more reliable information regarding the costs incurred. The research presented in this thesis considers cost reduction in three aspects: optimisation of production processes, accurate cost estimation and accounting. Due to the increasing number of combinatorial optimisation problems associated with the production of Printed Circuit Boards (PCB), it has attracted the attention of many researchers who tried to solve these problems with the aim of minimising the production cost. Therefore, PCB production is used in this research as a test-bed for the three aspects mentioned above. Regarding cost reduction in PCB manufacturing, three interrelated combinatorial optimisation problems are considered: the component placement sequencing problem, the feeder assignment problem and the board type sequencing problem. Solving these problems ensures cost reduction by reducing the time required for manufacturing PCBs. As for cost reduction in the costing and accounting aspects, the traditional standard costing and standard accounting have some problems that make them unsuitable for today's manufacturing. Standard costing allocates overhead to labour or machine hours, which leads to a distortion of product costs due to the fact that today's manufacturing relies more on technology and less on human power. As for standard accounting, it has some features and characteristics that contradict with the widely spread lean manufacturing. The deficiencies in standard costing and standard accounting may create more waste and lead to the wrong decisions being taken.A framework is developed to provide solution to the above-mentioned problems in an integrated environment. A mathematical formulation for the three PCB manufacturing-related problems is developed and solved using a metaheuristic-based algorithm. In order to deal with the costing and accounting part of the framework developed, Activity Based-Costing (ABC) and Lean Accounting (LA) are implemented on a PCB manufacturing facility using a case study. ABC is used to estimate the costs of manufacturing PCBs and provide detailed information on how the costs are incurred. As for LA, it is used to reduce the costs associated with the accounting system, which is achieved by eliminating and/or replacing accounting transactions and promoting lean measures.Simulation results obtained show an average reduction in total assembly time of 5.96% and 5.43% when Taboo Search (TS) and Genetic Algorithms (GA) metaheuristics are used respectively. The results also show how ABC can be used to identify the activities used in PCB manufacturing and calculate their costs. By targeting the most costly activities identified by ABC, the production costs can be reduced. Regarding LA, the results indicate how the accounting system costs can be reduced by eliminating some accounting transactions and processes or replacing them with less costly alternatives

Application of Plant Growth Promoting Microorganism and Plant Growth Regulators in Agricultural Production and Research

Plant growth-promoting microorganisms (PGPM) are groups of rhizosphere microorganisms capable of colonizing the root environment. Some of the microbes that inhabit this zone are bacteria and fungi that are capable of efficiently colonizing roots and rhizosphere soil. These microorganisms can be used as biofertilizers for improving agricultural production even under stressful environmental conditions. In contrast to PGPM, plant growth regulators (PGR) are chemical compounds that significantly affect the growth and differentiation of plant cells and tissues. They function as chemical messengers for intercellular communication and play a vital role in plant signaling networks as they are involved in the plant developmental process and a wide range of biotic and abiotic stress responses. The application of PGPM and plant growth regulators/hormones or the synthesis of PGR and signal transduction, perception, and cross-talk creates a complex network that plays an essential role in the regulation of plant physiological processes. A better understanding of the mechanism of action of PGPM and PGR and their roles in plant growth and development, interaction and independence in their action, and hormonal crosstalk under stresses is essential for agricultural production and research. Therefore, this book has contributions in the form of research and review papers from eminent scientists worldwide and discusses the role of PGPM and PGR in agriculture production and research, their potentials as biocontrol agents, their effects on physicochemical properties of soil, innovation for sustainable agriculture, their role in seed transplanting, and their role in mitigating biotic and abiotic stresses

ECOS 2012

The 8-volume set contains the Proceedings of the 25th ECOS 2012 International Conference, Perugia, Italy, June 26th to June 29th, 2012. ECOS is an acronym for Efficiency, Cost, Optimization and Simulation (of energy conversion systems and processes), summarizing the topics covered in ECOS: Thermodynamics, Heat and Mass Transfer, Exergy and Second Law Analysis, Process Integration and Heat Exchanger Networks, Fluid Dynamics and Power Plant Components, Fuel Cells, Simulation of Energy Conversion Systems, Renewable Energies, Thermo-Economic Analysis and Optimisation, Combustion, Chemical Reactors, Carbon Capture and Sequestration, Building/Urban/Complex Energy Systems, Water Desalination and Use of Water Resources, Energy Systems- Environmental and Sustainability Issues, System Operation/ Control/Diagnosis and Prognosis, Industrial Ecology