Mathematical modeling of heavy metals diffusion and removal from cylindrical cement forms coated with bio-film

A mathematical model is developed to predict bioleachi ng of heavy metals from long cylindrical shape cementitious samples. In this model, the metal concentration difference within the solid and its surface is considered as the main driving force for transport of metals to the surface of a sample at a given temperature and pressure. Fick’s first and second law are applied to explain the motion of contaminants in a long and uniform cylindrical solid. In addition, the model considers Michaelis-Menten type kinetics, a special case of the widely accepted Langmuir-Hinshelwood reaction mechanism, at the surface of the encapsulating cylinder. The resulting model is solved analytically by applying regular perturbation techniques and Laplace transform. Specifically, the mathematical model consisting of a partial differential equation describing the mass transfer of the targeted species as it moves through the encapsulating cylinder toward the surroundings. The nature of the species interaction at the surface of the cylinder renders an otherwise linear problem to be nonlinear. However, by applying a boundary perturbation technique, a series of linear problems are generated that can then be solved using traditional methods such as the Laplace Transform. The Residue Theorem is used to carry out the inversions yielding closed form solutions of the targeted species concentration profile. The model was benchmarked by using effective diffusivities and specific surface bio-reaction rate constants within published ranges. Values of the mass concentrations generated by the model for bioleaching of a number of metals namely cobalt, calcium, and chromium, from encapsulated cementitious cylindrical matrices are in reasonable agreement with those reported in the published literature

Novel Configurations of Ionic Polymer-Metal Composites (IPMCs) As Sensors, Actuators, and Energy Harvesters

This dissertation starts with describing the IPMC and defining its chemical structure and fundamental characteristics in Chapter 1. The application of these materials in the form of actuator, sensor, and energy harvester are reported through a literature review in Chapter 2. The literature review involves some electromechanical modeling approaches toward physics of the IPMC as well as some of the experimental results and test reports. This chapter also includes a short description of the manufacturing process of the IPMC. Chapter 3 presents the mechanical modeling of IPMC in actuation. For modeling, shear deformation expected not to be significant. Hence, the Euler-Bernoulli beam theory considered to be the approach defining the shape and critical points of the proposed IPMC elements. Description of modeling of IPMC in sensing mode is in Chapter 4. Since the material undergoes large deformation, large beam deformation is considered for both actuation and sensing model. Basic configurations of IPMC as sensor and actuator are introduced in Chapter 5. These basic configurations, based on a systematic approach, generate a large number of possible configurations. Based on the presented mechanisms, some parameters can be defined, but the selection of a proper arrangement remained as an unknown parameter. This mater is addressed by introducing a decision-making algorithm. A series of design for slit cylindrical/tubular/helical IPMC actuators and sensors are introduced in chapter 5. A consideration related to twisting of IPMCs in helical formations is reported through some experiments. Combinations of these IPMC actuators and sensors can be made to make biomimetic robotic devices as some of them are discussed in this chapter and the following Chapters 6 and 7. Another set of IPMC actuator/sensor configurations are introduced as a loop sensor and actuator that are presented subsequently in Chapter 6. These configurations may serve as haptic and tactile feedback sensors, particularly for robotic surgery. Both of these configurations (loop and slit cylindrical) of IPMCs are discussed in details, and some experimental measurements and results are also carried out and reported. The model for different inputs is studied, and report of the feedback is presented. Various designs of these configurations of IPMC are also presented in chapter 7, including their extension to mechanical metamaterials and soft robots

Chaotic translations on weighted Orlicz spaces

Let $G$ be a locally compact group, $w$ be a weight on $G$ and $\Phi$ be a Young function. We give some characterizations for translation operators to be topologically transitive and chaotic on the weighted Orlicz space $L_w^\Phi(G)$. In particular, transitivity is equivalent to the blow-up/collapse property in our case. Moreover, the dense set of periodic elements implies transitivity automatically

The impact of industrial pollution on macrobenthic fauna communities

Mossa creek is a long, deep, tidal canal in Iran. The creek stretches almost 56 km along the northwestern edge of the Persian Gulf. The creek contains numerous sources of organic pollution including industrial sewage effluent. A survey of the creek was performed assessing organic pollution, water properties, and the macrobenthic community. The need to assess the environmental status of marine and coastal waters encouraged the design of specific biotic indices to evaluate the response of benthic communities to human-induced changes in water quality. In this study of the benthic community structure in two creeks surrounding an industrial sewage discharge, water and sediment samples were collected at eight sites in the warm season (September) and cold season (February). Environmental data on physical and chemical variables were also collected from each site and a multivariate analysis was carried out to determine the effect of environmental factors on the biodiversity distribution. The result indicated that: Shannon's-weaver index has significant correlate with dissolved oxygen (DO) and organic matter (OM). In addition, in station near of the swage pollution biodiversity index, water quality and DO decreased and organic matter increased. However, very heavy pollution was observed according to the biodiversity index value in both seasons. The results showed that in both seasons 1, 2, 3 and 5 stations (which are located near the sewage output) in pollutant confine, 4 station in moderate confine and 6, 7, 8 stations located in un pollutant class. Also the results of water quality determine base on Welch index indicated that 1, 2, 5 stations in both season, 362.95 ha (7%) and other stations in moderate pollution load, 4885.73 ha (93%) located in high and moderate pollution load, respectively. Also, the results indicated that stations around the sewage outlet had less macrobenthic species and higher organic matter. On the contrary, the station furthest from the petrochemical industries (station located in Ghanam creek) had higher species diversity and consequently a higher value for the Shannon-Weaver diversity index. The present study also showed that Polychaetes, a biotic index of pollution biotic, were more abundant. Although Polychaetes were also recorded at all the other stations, these stations had greater biodiversity with different numerically dominant species such as: Isopoda, Decapoda, Gastropoda, Copepoda, Bivalvia, Pennatulacea, and Crustaceastations. Consequently, it was established that macrobenthic biodiversity was related to dissolved oxygen and the percentage of organic matter in the sediment.Key words: Biotic indices, pollution, macrobenthos

Catalytic dehydrogenation of amine borane complexes

A method of generating hydrogen includes the steps of providing an amine borane (AB) complex, at least one hydrogen generation catalyst, and a solvent, and mixing these components. Hydrogen is generated. The hydrogen produced is high purity hydrogen suitable for PEM fuel cells. A hydrolytic in-situ hydrogen generator includes a first compartment that contains an amine borane (AB) complex, a second container including at least one hydrogen generation catalyst, wherein the first or second compartment includes water or other hydroxyl group containing solvent. A connecting network permits mixing contents in the first compartment with contents in the second compartment, wherein high purity hydrogen is generated upon mixing. At least one flow controller is provided for controlling a flow rate of the catalyst or AB complex

Disjoint linear dynamical properties of elementary operators

We characterize disjoint hypercyclic sequences of wedge operators. Also, we give some sufficient conditions for a sequence of the dual wedge operators to be disjoint topologically transitive. Finally, we give some concrete examples and applications

Hypercyclic Sequences of weighted translations on hypergroups

In this paper, we characterize hypercyclic sequences of weighted translation operators on an Orlicz space in the context of locally compact hypergroups.Comment: 18 pages, Typos are corrected and one reference adde