Yes / This paper proposes the application of a hybrid genetic algorithm (GA) for scheduling storage tanks. The proposed approach integrates GAs and heuristic rule-based techniques, decomposing the complex mixed-integer optimization problem into integer and real-number subproblems. The GA string considers the integer problem and the heuristic approach solves the real-number problems within the GA framework. The algorithm is demonstrated for three test scenarios of a water treatment facility at a port and has been found to be robust and to give a significantly better schedule than those generated using a random search and a heuristic-based approach.

Yes / This paper proposes the application of a genetic algorithm based methodology for the scheduling of storage tanks. The proposed approach is an integration of GA and heuristic rule-based techniques, which decomposes the complex mixed integer optimisation problem into integer and real number subproblems. The GA string considers the integer problem, and the heuristic approach solves the real number problems within the GA framework. The algorithm is demonstrated for a test problem related to a water treatment facility at a port, and has been found to give a significantly better schedule than those generated using a heuristic-based approach.

The purpose of this thesis is to study the complete design for a circular prestressed concrete tank and the application of the principle of dynamic analysis to the design of the tank structure. A proposed method of circular prestressing is presented and the comparative study of the prevailing circular prestressing system is also included. The thesis is divided into four parts. The first part is a study of the structural analysis using the theory of the thin shell as an approach and the prestressed concrete design. The second part presents the proposed zig-zag extensioning method of circular pre-stressing. Numerical examples for the complete design procedure follow as illustrations. The third part makes a brief review on the dynamic analysis for the tank structure due to the earthquake disturbances In this section, only the application of an approximate energy method is discussed. The fourth part of this thesis is the comparison between different methods of circular prestressing including the Preload method, Mag1el-Blaton method, Freyssinet cable method Precast method, and the Zigâ zag extensioning method. Several construction problems are discussed. / Master of Science

Several tanks have failed due to intolerable differential settlements, causing major problems in most cases. The objective of this study is to optimize the bottom plate of the tank so that the differential settlements are reduced to a minimum. Circular plates on an elastic half-space are investigated and the improvements in differential settlements are reported. The plates are loaded by a uniform pressure, and the effects of edge loads, edge moments, and elastic restraints at the edge are considered. A plate with two annular segments having fixed radii is investigated for optimal thicknesses. The plate is also optimized by varying both the radii and the thicknesses. Another plate with three segments is studied, varying the radii and the thicknesses. In all these cases, the plates are examined for a wide range of relative stiffnesses. For a specific relative stiffness, a plate with ten segments of fixed radii is studied. Also, the contact stress distribution is investigated for the case of the three-segment plate. During the study, the results are compared to a uniform plate. As an outcome, the differential settlement is significantly improved compared to the widely used uniform plate. / Master of Science

This thesis is concerned with the effects of earthquakes on partially-filled water tanks. The analysis is applicable to rectangular water tanks, which have received little attention to date. The analysis is relatively involved and includes the derivation of the equations of motion for the vibration of the whole of tank by means of substructure synthesis, a stochastic analysis relating the random ground motion caused by earthquakes to the random vibration of the tank, a stochastic characterization of the fluid pressure and computation of the probability of failure of the tank. / Master of Science

In the past few years, great strides have been made toward simplification and improvement of the classical methods of the design of circular tanks. The need for a fast and efficient method by which engineers may determine the "indeterminate" stresses that exist in the walls and floors of circular tanks, of steel and concrete, has long been recognized. A simplified approach to the problem, which has been used by engineers for many years, merely employs the basic history of liquid pressure on the walls of pipes of large diameter. However, the use of this theory results in great waste of structural material. The advent of modern methods of placing reinforce concrete and the use of large, shallow settling tanks, has necessitated a more thorough investigation of the stress distribution both in tension and in bending, which exists in the tank wall, through the continuity between floor and wall. Credit for the introduction of a more rigorous analysis of the stresses in circular concrete tanks may be given to Mr. George S. Salter (1), whose theory has become quite popular since 1940, although the U.S. Navy (2) published charts and tables of tank stress distribution as early as 1924. A few existing theories will be discussed in Section II. Although there have been very few failures of tank structures, a more thorough study of tank design is still needed by the engineering profession. It is hoped that this thesis may, to some extent, contribute to forming a basis for future improvement and simplification of the popular methods of tank design. / Master of Science

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

An extensive study has been made of the factors affecting sample dispersion in flow injection analysis. This has included the effect of different manifold parameters on peak height and shape, and the use of various flow models to describe the physical processes involved. The factors investigated included sample flow-rate, tube length and diameter, sample volume, and the diffusion coefficient of the solute. The role of the detector has also been investigated, and was found to exert a strong influence on the observed dispersion behaviour of a flow injection manifold. In the light of this, a low volume flow cell was constructed which minimised the contribution of the detector to dispersion. Different modes of sample injection ("time" and "slug" injection) have been studied, and an automatic valve constructed in connection with the work. Both new and existing flow models have been evaluated in terms of their ease-of-use and ability to predict peak shape. Conditions for which the different models were valid were derived both experimentally and from consideration of the assumptions of the models. The applications of such models to the characterisation and design of flow manifolds has also been considered, and this approach compared to the purely theoretical and empirical approaches that have been described in the literature. The models examined in this thesis are the convection, diffusion, tanks-in-series, well-stirred tank, two-tanks in- parallel and two-tanks-in-series models. Finally, the practical implications of this work for the design of flow injection manifolds and the derivation of so-called "rules for dispersion" have been discussed, and suggestions made for further areas of research.

abstract: In 1916, in the middle of the First World War, Britain developed and deployed the first military tanks on a battlefield, signifying a huge step forward in the combination of mechanization and the military. Tanks represented progress in technical and mechanical terms, but their introduction to military goals and military environments required the men involved to develop immaterial meanings for the tanks. Tactically, tanks required investment from tank commanders and non-tank commanders alike, and incorporating tanks into the everyday routine of the battlefront required men to accommodate these machines into their experiences and perspectives. Reporting the actions of the tanks impelled newspapers and reporters to find ways of presenting the tanks to a civilian audience, tying them to British perspectives on war and granting them positive associations. This thesis sought to identify major concepts and ideas as applied to the British tanks deployed on the Western Front in the First World War, and to better understand how British audiences, both military and civilian, understood and adopted the tank into their understanding of the war. Different audiences had different expectations of the tank, shaped by the environment in which they understood it, and the reaction of those audiences laid the foundation for further development of the tank. / Dissertation/Thesis / Masters Thesis History 2018

Parametric roll resonance is a dangerous resonance phenomenon affecting several types of ships, such as destroyers, RO-RO paxes, cruise ships, fishing vessels and especially container ships. Worst case, parametric roll is capable of causing roll angles of at least 50 degrees, and damage in the tens of millions of US dollars. Empirical and mathematical investigations have concluded that parametric roll occurs due to periodic changes in the waterplane area of the ship. If the vessel is sailing in longitudinal seas, with waves of approximately the same length as the ship, and encounter frequency of about twice the natural roll frequency, then parametric resonance can occur. While there is a significant amount of literature on the hydrodynamics of parametric roll, there is less on controlling and stopping the phenomenon through active control. The main goal of this thesis has been to develop controllers capable of stopping parametric roll. Two main results on control are presented. To derive, analyze and simulate the controllers, it proved necessary to develop novel models. The thesis thus contains four major contributions on modeling. The main results are (presented in order of appearance in the thesis): Six-DOF computer model for parametric roll One-DOF model of parametric roll for non-constant velocity Three-DOF model of parametric roll Seven-DOF model for ships with u-tanks of arbitrary shape Frequency detuning controller Active u-tank based controller for parametric roll