Iron control during acidizing plays a key role in the success of matrix treatment. Ferric ion precipitates in the formation once the acid is spent and the pH exceeds 1-2. Precipitation of iron (III) within the formation can cause formation damage. Chelating agents such as EDTA and NTA are usually added to acids to minimize iron precipitation. Drawbacks of these chelating agents include limited solubility in strong acids and poor environmental profile. Hydroxy EDTA was introduced because of its higher solubility in 15 wt% HCl. However, its solubility in 28 wt% HCl is low and it is not readily biodegradable. In this study we studied the formation damage caused by iron precipitation in acidizing operations and tested the chelate L-glutamic acid, N,N-diacetic acid (GLDA). This chelant is soluble in higher concentrations of HCl. It is readily biodegradable, and is an effective iron control agent. A study was conducted to study the concentration of iron at different pHs ranging from 1-4 without the presence of any chelating agent at room temperature. A similar study was conducted in the presence of a chelating agent. To simulate field conditions, coreflood tests were conducted on Indiana Limestone, Austin Chalk and Pink Desert. Tests were conducted with and without the chelant. Samples of core effluent were collected and iron and calcium concentrations were measured using atomic absorption spectroscopy (AA). The cores were scanned using X-ray before and after acid injection. Results indicated that precipitation of iron can cause serious reduction in core permeability. The chelate was found to be very effective in chelating iron upto 300 degrees F. No permeability reduction was noted when GLDA was added to the acid. Material balance calculations show that significant amount of the iron that was added to the injected acid was produced when GLDA was used. This chelant is effective, environmentally friendly and can used up to 300 degrees F.

Actually, a whole new class of web user is developing. These users are computer programs that have the ability to access the Web in much the same way as a human user with a browser does. There are many names for these kinds of programs, and these names reflect many of the specialized tasks assigned to them. Spiders, bots, and aggregators are all so-called intelligent agents, which execute tasks on the Web without the intervention of a human being. In this research we will examine the differences between them and study possibilities to create user friendly programming toll which would be able to generate such kind of programs.

Over the last two decades, sanitation policy and development has undergone a paradigm shift away from heavily-subsidized, supply-driven approaches towards behavioral-based demand-driven approaches. These current approaches to increase sanitation demand are multi-faceted, requiring multiple stakeholders with varying degrees of interest, knowledge, and capacity. Although efforts exist to increase sanitation access by incorporating engineering design principles with implementation planning approaches, these groups generally work independently without strong connections, thus reducing the potential of their impact. As a result, the design of appropriate sanitation technology is disengaged from the implementation of acceptable technology into communities, disconnecting user preference integration from sanitation technology design and resulting in fewer sanitation technologies being adopted and used. To address these challenges in developing successful interventions, this research examined how user preferences for specific attributes of appropriate sanitation technologies and their respective implementation arrangements influence their adoption and usage. Data for the study included interviews of 1002 sanitation users living in a peri-urban area of South Africa; the surveyed respondents were asked about their existing sanitation technology, their preferences for various sanitation technology design attributes, as well as their perspectives on current and preferred sanitation implementation arrangements. The data revealed that user acceptability of appropriate sanitation technology is influenced by the adoption classification of the users. Through the identification of motives and barriers to sanitation usage that were statistically significant, it exhibited the need to differentiate users who share private sanitation from those use communal sanitation facilities. Results also indicated that user acceptability of appropriate sanitation systems is dependent on the technical design attributes of sanitation. The development of utility functions detailed the significance of seven technical design attributes and determined their respective priorities. An agent-based simulation examined how user preferences for sanitation technology design and implementation influence its adoption and usage. Findings suggest that user acceptability of sanitation technology is dependent on both the technology design and the implementation arrangement being preferred.

We study the influence of technological efficiency and organizational inertia on the emergence of competition when firms decide myopically. Using an agent-based computer simulation model, we observe the competitive reaction of a former monopolist to the advent of a new competitor. While the entrant uses a new technology, the monopolist is free either to stick to his former technology or to switch to the new one. We find that?irrespective of details regarding the demand side?a change of industry leadership occurs only if the new (?disruptive?) technology is not too efficient and organizations are inert. (author's abstract) / Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"

This study was performed to examine the performance of an equity based crowdfunding campaign, as well as seeking to describe the risks, complications and the opportunities that this kind of funding brings. The study was conducted by an empirical case study of a company that was about to initiate an equity based crowdfunding campaign. The conclusion is that the planning of an equity based crowdfunding campaign is time consuming and requires knowledge in many different areas. Therefore it is important to identify in which areas skills and resources already are available within the company, and where it must be obtained through a learning process. The report also highlights that equity based crowdfunding, because of legal restrictions surrounding the issue of unlisted shares, can not be marketed as other types of crowdfunding. This leads to the conclusion that those who invest in equity based crowdfunding do not necessarily belong to the crowd that crowdfunding is generally associated with. Arguments can be made that this crowdfunding model rather resemble traditional angel networks. A technical study was also made about the company's products. The result of the technical study can be used by customers to get a clearer understanding of the company's products, but also by the company itself as a good insight into how their products work in practice and to develop the existing products.

This study was performed to examine the performance of an equity based crowdfunding campaign, as well as seeking to describe the risks, complications and the opportunities that this kind of funding brings. The study was conducted by an empirical case study of a company that was about to initiate an equity based crowdfunding campaign. The conclusion is that the planning of an equity based crowdfunding campaign is time consuming and requires knowledge in many different areas. Therefore it is important to identify in which areas skills and resources already are available within the company, and where it must be obtained through a learning process. The report also highlights that equity based crowdfunding, because of legal restrictions surrounding the issue of unlisted shares, can not be marketed as other types of crowdfunding. This leads to the conclusion that those who invest in equity based crowdfunding do not necessarily belong to the crowd that crowdfunding is generally associated with. Arguments can be made that this crowdfunding model rather resemble traditional angel networks. A technical study was also made about the company's products. The result of the technical study can be used by customers to get a clearer understanding of the company's products, but also by the company itself as a good insight into how their products work in practice and to develop the existing products.

No description available.

Many practical problems raise the challenge of making decisions over time in the presence of both dynamic complexity and pronounced uncertainty regarding evolution of important factors that affect the dynamics of the system. In this thesis, we provide an end-to-end implementation of an easy-to-use system to confront such challenges. This system gives policy makers a new approach to take complementary advantage of decision analysis techniques and System Dynamics by allowing easy creation, evaluation, and interactive exploration of hybrid models. As an important application of this methodology, we extended a System Dynamic model within the context of West Nile virus transmission in Saskatchewan.

No description available.

La fonction détection, reconnaissance et identification de cibles (DRI) impose l'intégration de connaissances hétérogènes en grande quantité. Ceci nous conduit vers des architectures distribuant la connaissance et permettant d'effectuer des traitements en parallèle et en concurrence. Nous proposons une approche multi-agent basée sur la mise en oeuvre d'agents spécialisés répondant aux principes d'incrémentalité, de distribution, de coopération, de focalisation et d'adaptation. L'architecture utilisée est de type multi-thread. Elle est dotée d'un administrateur et spécifie les moyens de communication entre les agents. Ceux-ci sont définis par leur rôle, leurs comportements et les informations qu'ils manipulent et qu'ils produisent. À un instant donné, différents agents coexistent dans l'image. Chacun dispose d'une autonomie pour accéder aux données et élaborer sa propre stratégie en fonction des informations disponibles. La planification est prise en charge localement au niveau de l'agent. Les connaissances nécessaires sont spécifiées dans une base de connaissances partagée par tous les agents. Les informations acquises sont stockées dans un modèle du monde. Le système se construit et vient s'enrichir au cours du temps, ceci impose une stratégie incrémentale dans la mise à jour des hypothèses. Cette modélisation est faite sous forme de réseaux bayésiens.