887 resultados para methods of analysis


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This review will summarize the significant body of research within the field of electrical methods of controlling the growth of microorganisms. We examine the progress from early work using current to kill bacteria in static fluids to more realistic treatment scenarios such as flow-through systems designed to imitate the human urinary tract. Additionally, the electrical enhancement of biocide and antibiotic efficacy will be examined alongside recent innovations including the biological applications of acoustic energy systems to prevent bacterial surface adherence. Particular attention will be paid to the electrical engineering aspects of previous work, such as electrode composition, quantitative electrical parameters and the conductive medium used. Scrutiny of published systems from an electrical engineering perspective will help to facilitate improved understanding of the methods, devices and mechanisms that have been effective in controlling bacteria, as well as providing insights and strategies to improve the performance of such systems and develop the next generation of antimicrobial bioelectric materials.

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Damage tolerant hat-stiffened thin-skinned composite panels with and without a centrally located circular cutout, under uniaxial compression loading, were investigated experimentally and analytically. These panels incorporated a highly postbuckling design characterised by two integral stiffeners separated by a large skin bay with a high width to skin-thickness ratio. In both configurations, the skin initially buckled into three half-wavelengths and underwent two mode-shape changes; the first a gradual mode change characterised by a central deformation with double curvature and the second a dynamic snap to five half-wavelengths. The use of standard path-following non-linear finite element analysis did not consistently capture the dynamic mode change and an approximate solution for the prediction of mode-changes using a Marguerre-type Rayleigh-Ritz energy method is presented. Shortcomings with both methods of analysis are discussed and improvements suggested. The panels failed catastrophically and their strength was limited by the local buckling strength of the hat stiffeners. (C) 2001 Elsevier Science Ltd. All rights reserved.

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Considerable time, research money and expertise has been spent exploring the complex reality of ethno nationalist conflict and the role that public management plays in supporting the transition from violent conflict to stability, order and prosperity (Esman 1999; Guelke and Milton-Edwards 2000; Brinkerhoff 2005; Brinkerhoff, Wetterberg et al. 2012; Rao 2014). However, there seems to be a gap in relation to the practical challenges of managing change within, through and beyond such conflict. This paper aims to begin the process of putting a framework around the real experience of public management in conflict and transition by shifting the lens of analysis from macros concerns about sequencing interventions (Rao 2014) and legitimate requirements of security, stability and service delivery (Brinkerhoff, Wetterberg et al. 2012) to a micro analysis of the attitudes, behaviours, challenges and compromises held and faced by those public servants on the front line of conflict management and conflict transformation processes. Using senior managers as the unit of analysis and Northern Ireland as an embryonic case study, this paper discusses the links between ethno nationalist societal conflict, public sector reform and manager behaviour. In doing so, it highlights some initial data from an early pilot study into the experiences of individuals in significant public service roles at various stages of the NI conflict / peace process and draws some tentative conclusions about the viability of a wider study.

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The number of older people globally is increasing, contributing to a growing burden of morbidity and mortality. With this shift in population demographic, comes a new challenge in terms of appropriate healthcare for the over 65 years age group. As medication is the principal therapeutic intervention, it is essential that it be fully optimised, to meet the needs of this heterogeneous population. The most common routes of drug administration are oral and injectable, which may display some limitations for older people, in cases of dysphagia or frailty for example. This review considers alternative methods of drug delivery to the norm, specifically discussing the nasal, pulmonary and transdermal routes, as well as novel orally disintegrating tablets. The changing physiology as ageing occurs must be considered in the development of novel drug delivery devices. This review considers the various aspects of ageing that will influence future drug formulation design and development.

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The purpose of this study was to determine novice t~ache~s' perceptions of th~ extent to which the Brock University teacher education program focused on strategies for promoting responsibility in students. Individual interviews were conducted with ten randomly selected teachers who were graduates of this teacher education program between the years of 1989 and 1992, and a follow-up group discussion activity, with the same teachers, was also held. Findings revealed that the topic of personal responsibility was discussed within various components of the program, including counselling group sessions, but that these discussions were often brief, indirect and inconsistent. Some of the strategies which the teachers used in their own classrooms to promote responsibility in students were ones which they had acquired from those counselling group °sessions or from associate teachers. Various strategies included: setting ~lear expectations of students with positive and negative consequences for behaviour (e.g., material rewards and detentions, respectively), cemmunic?ting'with other teachers an~ parents, and -. suspending students from school. A teacher's choice of any particular strategy seemed to be affected by his or her personality, teaching sUbject and region of employment, as well as certain aspects of the teacher education program. It was concluded that many of the teachers appeared to be controlling rude and vio~ent- behaviour, as opposed to promoting responsible behaviour. Recommendations were made for the pre-service program, as well as induction and inservice programs, to increase teacher preparedness for promoting responsible student behaviour. One of these recommendations addressed the need to help teachers learn how to effectively communicate with their students.

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The purpose of this study was to examine the disability discourses present in Ontario elementary schools curriculum. The study used a critical social analysis perspective to employ a textual discourse analysis on the Planning [title of subject] Programs for Students with Special Education Needs (PPSSEN) section of the curriculum. The present study utilized Parker's (1992) seven criteria for distinguishing discourses and discovered five main discourses; Independent, dependent, legal, scientific and agency discourses. The second step to this research was the placement and discussion of these five discourses on three diverse texts, Paulo Freire's (2008) Pedagogy o/ the Oppressed, Psychiatry Inside Out, Selected writings of Franco Basaglia, written by Scheper-Huges and Lovell (1987) and Aronowitz and Giroux's (1985) Education Under Siege: The Conservative, Liberal and Radical Debate over Schooling. These unique perspectives were used as methods of analysis tools to further analyze the dominate disability discourses. The texts provided textual support in three major areas; dialectics, critical education and structural conditions of power and language of traditional roles and responsibilities. The findings and discussions presented in this project contain significant implications for anyone involved with students with disabilities in any education system.

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The thesis is an introduction to our attempts to evaluate the coordination behaviour of a few compounds of our interest. Semicarbazones and their metal complexes have been an active area of research during the past years because of the beneficial biological activities of these substances. Tridentate NNO semicarbazone systems formed from heterocyclic and aromatic carbonyl compounds and their transition metal complexes are well-authenticated compounds in this field and their synthesis and characterization are well desirable. Hence, we decided to develop a research program aimed at the synthesis and characterization of novel semicarbazones derived from 2-benzoylpyridine and 2-acetylpyridine and their transition metal complexes. In addition to various physicochemical methods of analysis, single crystal X—Ray diffraction studies were also used for the characterization of the complexes.

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The objective of this research is to study the feasibility of bioremediating the oily sludge from a refinery site. Three different methods of waste treatment were tried i.e. phytoremediation, land farming and microbial enhanced oil separation in laboratory scale treatment systems. A multiprocess approach by combination of phytoremediation, biostimulation and microbial enhanced oil separation is also presented. The methods of analysis, experimental procedure, and results are incorporated into five chapters of this thesis entitled "Bioremediation of petroleum sludge through phytoremediation, land farming and microbial enhanced oil separation.

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Electroanalytical techniques represent a class of powerful and versatile analytical method which is based on the electrical properties of a solution of the analyte when it is made part of an electrochemical cell. They offer high sensitivity, accuracy, precision and a large linear dynamic range. The cost of instrumentation is relatively low compared to other instrumental methods of analysis. Many solid state electrochemical sensors have been commercialised nowadays. Potentiometry is a very simple electroanalytical technique with extraordinary analytical capabilities. Since valinomycin was introduced as an ionophore for K+, Ion Selective Electrodes have become one of the best studied and understood analytical devices. It can be used for the determination of substances ranging from simple inorganic ions to complex organic molecules. It is a very attractive option owing to the wide range of applications and ease of the use of the instruments employed. They also possess the advantages of short response time, high selectivity and very low detection limits. Moreover, analysis by these electrodes is non-destructive and adaptable to small sample volumes. It has become a standard technique for medical researchers, biologists, geologists and environmental specialists. This thesis presents the synthesis and characterisation of five ionophores. Based on these ionophores, nine potentiometric sensors are fabricated for the determination of ions such as Pb2+, Mn2+, Ni2+, Cu2+ and Sal- ion (Salicylate ion). The electrochemical characterisation and analytical application studies of the developed sensors are also described. The thesis is divided into eight chapters