McGill University Thèses et mémoires publiés en 1992

This case study examines the educational needs of students attending two social affairs schools in Quebec. The aim was to determine why these youths continue to do poorly academically and why they fail to thrive once they leave the child welfare system, as described in the literature. Individual and environmental factors that hinder academic progress were investigated ethnographically. The chronic under-achievement characteristic of youths attending the social affairs schools appears to be due to a number of individual factors such as frequent school changes as well as to the mental health model that guides the social affairs schools. This model …  Read more

The kinematics, temporal and sequential organization of the lower limb joints were assessed during jump downs at a constant height (45 cm) in seven practised subjects under four conditions: (SS) stiff takeoff and landing, (SC) stiff takeoff and compliant landing, (CS) compliant takeoff and stiff landing, and (CC) compliant takeoff and landing surfaces. The timing and sequencing of joint motions were unaffected by the compliance of the takeoff or landing surfaces. During takeoff ankle adjustments may have been influenced by proprioceptive inputs about the takeoff surface compliance, whereas knee adjustments could mean that the landing program interferes with the takeoff. …  Read more

The present study attempted to characterize laxity in cruciate deficient knees using the Genucom System comparing the neutral to the resting position of the tibia. A quadriceps active technique was compared to a passive protocol at four knee flexion angles: 60, 70, 80 and 90 degrees. Eight ACL and eight PCL injured subjects performed active and passive anterior-posterior knee drawer tests. These tests were performed during two sessions to verify their reliability. Posterior and anterior laxity were recorded for the PCL and the ACL injured subjects, respectively. Laxity was measured at forces of 60, 90 and 130 Newtons. A feedback …  Read more

The importance of discontinuous hormonal signals in endocrine communications is suggested by the ability of sustained hormonal signals to shut down, as opposed to stimulate, target cells, and by the observation that a change in pulse pattern can alter the response elicited. Serial sampling of the serum in catheterized, conscious, freely-moving rats was employed to investigate two aspects of pulsatility in the hypothalamo-pituitary-testicular feedback loop regulating reproduction in the adult male. First, in response to treatment with moderate to high doses of the testosterone (T) metabolite, dihydrotestosterone (DHT), pituitary responsiveness to exogenous LHRH was suppressed, and elevated post-castration mean LH …  Read more

Henry-Emile Chevalier was forced in exile by the December 1851 Coup d'Etat in France. In March 1853, he came to Montreal and joined Georges-Hippolythe Cherrier who had just started a new periodical called La Ruche Litteraire Illustree. In addition, during his stay in Montreal, Chevalier worked for several periodicals, was an active member of the Institut canadien de Montreal, and wrote many novels and serials depicting Canada's exoticism. This thesis will provide the most accurate biography of Chevalier up to date, it will also present an analysis of the exoticism in his novels and serials (1853-1960), and of his contribution …  Read more

The work of Jean-Jacques Lequeu (1757-1826) is often used by architectural historians to demonstrate the erosion of the principles of classical architecture at the end of the eighteenth century. The Nouvelle Methode appliquee aux Principes elementaires du dessin completed by Lequeu in 1792, a drawing method showing the correct proportions of the face obtained through geometry, reveal another Lequeu, one sympathetic to the architectural theories of his time. The similarities between the Nouvelle Methode and the Dissertation sur les especes naturelles by the Dutch naturalist Petrus Camper (1722-1789) show the importance of the notion of caractere in the structure of …  Read more

This thesis analyzes Kenneth Burke's rhetoric of identification. I will examine the extent to which Burke's earliest critical writings, which focus on the suasive nature of literary forms, affected the writing of his later critical works, which deal with how language functions as a type of symbolic action. In his later texts, Burke breaks with his earlier concern with literary discourse by attempting to expound a critical theory that accounts for historical change, human motivation and the role of language in collective communities. He argues that language motivates people to identify with a certain sets of beliefs by transcending an …  Read more

Automatic repeat request (ARQ) is a widespread technique for error control in data communication systems. This research examines the performance of conventional ARQ schemes over fading channels. The basic Gilbert-Elliott two-state Markov model is used to represent these channels. This basic model is recursively extended to a 2$ sp{n}$-state Markov chain suitable for n-bit block codes. Using this 'Extended Gilbert-Elliot' model, an approximation of the throughput efficiency of the conventional ARQ schemes is derived. This approximation is particularly valid for slow fading channels. Furthermore, performance plots are obtained, showing the effects of channel fading on throughput efficiency: ARQ performance deteriorates …  Read more

The morphology and properties of polymer blends are closely related to processing conditions. The minor phase dimensions usually range from 0.1 to 10 $ mu$m. A skin/core morphology, with a minor phase undergoing variations in orientation and aspect ratio from the surface to the core of the material is observed in processes such as the injection molding of blends. The use of optical inspection is a potential tool to control the stability and the quality of the product on-line. In this thesis, polymer composites made from different glass fibers and glass microspheres embedded in a matrix of PS are used …  Read more

This study consists of evaluating the effects of zidovudine or ribavirin treatment on the humoral response to human immunodeficiency syndrome (HIV-1) in a cohort of 36 HIV-1 seropositive patients. Viral neutralization antibodies were demonstrated against HTLV$ sb{ rm IIIb}$ virus while titers of circulating antibody-dependent cellular cytotoxicity (ADCC) antibodies were measured against the HIV-1 envelope protein, gp120, using the vaccinia virus expression system which has been successfully used to express foreign viral proteins in target cells. Virologic (viral isolation) and immunologic (CD4$ sp+$ cells) parameters were also monitored pre and post antiviral therapy. The results indicate that patients receiving zidovudine …  Read more

By the end of the eighteenth century, as imagination makes its appearance behind representation, man enters the field of knowledge and literature emerges in the world of fiction. L'Architecture of Claude-Nicolas Ledoux is too complex a work to make its mapping possible in such a short study. I therefore tried to unfold the work through the question that seemed to me to be the most revelatory of this time. The notion of caratere derived from the specific codes of a culture where representation was the foundation of a possible order. In L'Architecture, between the fictional character and his caractere is …  Read more

The bursa of Fabricius is essential for normal development of chicken B lymphocytes. To analyze early (pre-bursal) stages of B cell development, day 14e-15e chick embryo bone marrow cells were transformed with the avian REV-T(CSV) retrovirus and cloned. Some clones contained rearranged and expressed immunoglobulin genes, demonstrating that the bursal microenviornment is not required for immunoglobulin gene rearrangement and expression. In order to examine the sequence of immunoglobulin gene rearrangements during chicken B cell development, day 12e embryo bursal cells were transformed using REV-T(CSV). Clones containing either rearranged immunoglobulin light chain or rearranged immunoglobulin heavy chain genes demonstrated that chicken …  Read more

This study investigates the coping methods, styles and strategies of 35 homosexual men who are infected with the human immunodeficiency virus (HIV) but remain asymptomatic. Subjects were recruited from a Montreal AIDS clinic and support groups for men with HIV. The effectiveness of the coping mechanisms were evaluated by correlating these to measures of depression, state and trait anxiety, psychosomatic symptomatology, perceived social support and global health. Data analyses revealed that men with HIV infection were generally well-adjusted and employed a variety of coping techniques. Cognitive attempts at coping were the most frequently used and were related to elevated levels …  Read more

The objective of this study was to examine the measurement properties of the Balance Scale. In two longitudinal studies, 113 elderly subjects and 70 acute stroke patients were monitored on 4 occasions during periods of one year and 12 weeks, respectively. Results showed that Balance Scale scores were associated with the occurrence of subsequent falls and clinical judgments of balance, and could discriminate subjects by their use of mobility aids and the location of their follow-up evaluation. Balance scores were strongly associated with measures of functional status and motor performance in stroke patients over the 12 weeks. Moreover, changes in …  Read more

Syntactic and semantic abilities were compared in 12 patients with mild to moderate dementia of the Alzheimer-Type (DAT) and matched controls. In Experiment 1A, performance on naming, word-picture matching, probe verification, and syntactic comprehension was assessed. Experiment 1B tested subjects' ability to use syntactic, semantic, and sentence contexts to choose the correct pronunciation of homographs and the correct spelling of homophones. Group data and individual patterns were reported. The main results revealed that: (1) all patients showed syntactic and semantic deficits; (2) patients were better able to use sentence contexts than syntactic or semantic contexts in isolation; syntax was not …  Read more

Bray, Garth M. (Supervisor)  Read more

Cordierite-orthoamphibole rocks associated with contrasting polymetallic mineralization occur in a wide range of metamorphic conditions in the Atik Lake, Manitoba, and Nemiscau and Montauban, Quebec, metamorphic terranes. Lithogeochemistry and geothermobarometry investigations using whole rock major, trace and rare earth elements and mineral chemistries have established the chemical and physical changes that occurred during hydrothermal alteration and subsequent regional metamorphism. The Log(Ratio) method, utilizing ratio profiles of the immobile elements $ rm Al sb2O sb3$, TiO$ sb2$, Zr, Nb, Y V and Cr, was designed to identify the protoliths of the metamorphosed altered rocks. Detailed geothermobarometry and textural evidence indicate that …  Read more

The cellular activity in bone and cartilage tissue is controlled by substances present in the osseous environment. Using representative cell lines, modulation of osteoblastic and chondrocytic phenotypic markers such as hormone-responsiveness, enzymatic activities, and matrix production by osteotropic factors was examined in vitro. In UMR 106 cells, a rat osteoblast-derived osteosarcoma cell line, a differential distribution of EGF and PTH receptors over proliferating and quiescent cells, respectively, was observed. EGF treatment resulted in expansion of a less differentiated population characterized by decreased PTH- and CT-stimulated adenylate cyclase and binding capacity, and increased CGRP-responsiveness. Using immunocytolysis, a mixed osseous cell population …  Read more

Supplementation of a minimal medium with KHCO$ sb3$ and some amino acids reduced the duration of the lag period for the growth of the marine bacterium Deleya aesta 134 at sub-optimal Na$ sp+$ concentrations and decreased the minimal Na$ sp+$ concentration allowing growth, to 8mM. Na$ sp+$ was required for the transport of most metabolites into D. aesta 134, while some compounds were taken up by both a Na$ sp+$-dependent and a Na$ sp+$-independent system. Phosphate transport was not affected by Na$ sp+.$ Na$ sp+$ was also required for the oxidation of exogenous succinate. Evidence for the presence in D. …  Read more

This study examines two important influences that shape John Donne's "Holy Sonnets": The Ignatian meditative tradition and the devotional tradition of the psalm genre. It argues that their confluence in his sonnets gives rise to unique rhetorical structures and strategies that reflect the doctrinal uncertainties of his age.  Read more

This study evaluates the effects of an eight week, school-based, preventive intervention programme on the adjustment of children to divorce. Thirty-three later latency stage children (9 to 12 year olds) were evaluated before and after intervention on the Child Behavior Check List by parents (Achenbach & Edelbrock, 1983) and teachers (Edelbrock & Achenbach, 1984) for behaviour problems. Children's self reports on their problematic beliefs about divorce (Kurdek and Berg, 1987), self-perceived competence (Harter, 1985), and trait anxiety levels (Reynolds & Richmond, 1985) were assessed. Subsequent to the intervention children had significantly fewer misconceptions about divorce, had increased perceived social acceptance, …  Read more

This dissertation will outline the integrated circuit design of an adaptive phase-locked loop that will be used to synchronize the sampling clock for a video speed analog to digital converter. The adaptive phase-locked loop (PLL) that will be described has not previously been used in the application of video synchronization. We shall demonstrate that this type of PLL will be able to out perform a static PLL in terms of its acquisition time, while still achieving a comparable noise performance. The PLL we shall describe will also be designed to be integrated on a single sub-micron BiCMOS chip. It is …  Read more

Since its inception, the contemporary debate between liberals and communitarians has been a dispute mired in misunderstanding. The source of this, I want to argue, is that liberals and communitarians disagree about the appropriate relationship between theory and practice and hence the nature of the political theory itself. To help bring about a more productive debate, then, I suggest that this theme be placed front an centre in the writings of its protaganists.  Read more

Alpha-fetoprotein (AFP) is a major plasma protein in the fetus and newborn. Extensive studies in both human and murine systems defined a selective down-regulatory role for AFP on certain types of immune reactions in vitro. Direct evidence was obtained in experimental models of autoimmune disease showing that mouse and human AFP can, in a predictable fashion, influence in vivo immune parameters. However, attempts to define the molecular basis of the immunoregulatory functions of AFP have until now been handicapped by the lack of an appropriate consistent source for pure AFP in quantities suitable for detailed investigations. The aim of my …  Read more

Although Buddhism denies the existence of a permanent individual entity, the tradition nevertheless makes frequent use of the "aggregate" scheme when asked to explain the elements at work in the individual. Through a detailed analysis of each of these five aggregates (pancakkhandha). I first intend to establish how the Theravada tradition views their interaction, with each other and with the external world. Secondly, I will attempt to offer strong evidence that the traditional order systematically used for the enumeration of the five aggregates is significant. This will be evidenced by establishing a correlation between the five aggregates and the eight …  Read more

This study investigated the predatory behaviour of kestrels on insect prey in a modified open-field arena, and assessed the effects of T. pseudospiralis infections on the sequence of predatory behaviours, hunting efficiency and choice of hunting method of the birds. Choice of hunting method in kestrels was related to their appraise energy expenditure and relative success. Hunting from a perch was more common, presumably less strenuous and more successful than hunting afoot. Hunting prey confined to the vertical walls of the arena was considered more strenuous and was less successful than hunting freely-roaming ground prey. Infection with T. pseudospiralis did …  Read more

The function of CABP1, a novel cAMP-binding protein in Dictyostelium discoideum, has been investigated. Previously, it has been shown that the molecular weight of CABP1 varies in different strains and that this variation is correlated with differences in response to cAMP. Sequence analysis showed that compared to its counterpart in strain AX2, the gene encoding CABP1 of strain V12M2 is missing 27 bp. AX2 transformants expressing the capA gene of V12M2 exhibited no change in phenotype, suggesting that CABP1 is not involved in the features examined or that the V12M2 variant is recessive. Disruption of capA by homologous recombination was …  Read more

This dissertation investigates the structure of Internally Headed Relative Clauses (henceforth, IHRCs) within the framework of Government and Binding Theory. I propose that the structure of IHRCs involves a modifying clause predicted of a head. We provide empirical as well as conceptual arguments showing that the head of an IHRC is a pro licensed by coindexation with the internal head. Following Safir's (1986) LCR, this licensing must be mediated by A$ sp prime$-Binding, which is effected by operator-movement to COMP within the modifying clause. Island Constraints provide evidence for operator-movement in IHRCs. IHRCs pattern with other Wh-constructions in this way. …  Read more

The dietary and medicinal uses of indigenous green vegetables were studied quantitatively over a 13-month period in a rural, semi-rural and urban K'ekchi population in Guatemala. Seventeen species of indigenous greens were consumed, with seasonal variation in intake (p $<$.001) being related to agricultural practices. There was a lower frequency of consumption of greens among the urban group (p $<$.001). Within, and between, the communities, individuals exhibited heterogeneity in dietary intake and approaches to treatment of helminthic infection. There was no association between dietary intake of indigenous greens and the socioeconomic indicators measured (age, type of employment, household size and …  Read more

Two previously identified sequence alterations in the androgen receptor gene of patients with complete androgen resistance are studied to prove their pathogenicity. Family studies confirm that the mutation segregates with the phenotype and that the mothers are heterozygous carriers. In one family a sibling of the patient is identified as a heterozygous carrier. Mutant cDNAs encoding the mutant receptors are constructed and expressed in COS-1 cells. The resulting mutant receptors show a decreased apparent equilibrium constant for androgens, faster dissociation rates and impaired transactivation. Further studies reveal that both mutant receptors were either inactivated or destroyed in the presence of …  Read more

Sustainable development requires the integration of ecological and social concerns into economic activities. Recent trends in environmental impact assessment (EIA) suggest the eventual use of the EIA process to link socio-environmental attributes with economic decision-making thus allowing for the transition towards a sustainable future. This thesis is an examination of the proposed Federal Environmental Impact Assessment Act of Canada and the extent to which its provisions seek to ensure a move towards sustainable development.  Read more

By analogy with the Makkai duality for first order logic, we develop a duality theory for $ kappa$-exact categories in which the structure on the model categories is that induced by $ kappa$-reduced products. The main theorem, a strong completeness result, states that for any small $ kappa$-exact category $F$, the functor $F { buildrel{e sb F} over longrightarrow} hom({ bf Mod}F,{ bf Sets})$ defined by evaluation is an equivalence of categories, where $hom({ bf Mod}F,{ bf Sets})$ is the category of functors from ${ bf Mod}F$ to Sets which preserve the reduced product structure.  Read more

The work performed can be divided into three stages. The first stage involved the development and study of a transparent heat pipe which served to illustrate the principles of heat pipes, specifically, thermosyphons or wickless heat pipes. The second stage dealt with the conception, construction and study of a laboratory scale heat pipe injection lance. The knowledge gained in the laboratory was used to build two pilot scale heat pipe injection lances, Mark I and Mark II, in the third stage of this work. These lances were tested in the copper converting furnace at the Kidd Creek smelter. Through the …  Read more

Normal and diseased human tissues were analyzed for the expression of genes of the carcinoembryonic (CEA) family. The use of portions of the CEA and NCA cDNA clones as hybridization probes has shown the existence of CEA and NCA transcripts in colon mucosa, NCA transcripts in breast tumours, and NCA and a third CEA-like transcript (CGM6) in chronic myelocytic leukemia (CML) cells. A library prepared from CML cells was used to isolate a cDNA clone of CGM6. The predicted product of this novel CEA family member displays 85% sequence similarity to CEA and NCA and its expression is limited to …  Read more

I investigate the free field realization (FFR) of various extended conformal field theories (ECFT's). More specifically, I first present a systematic method that allows the construction of the exponential type screening currents in terms of free fields in the case of the ECFT's with Kac-Moody algebras. This method is explicitly illustrated through the $su(n) sb{k}$ and $sp(4) sb{k}$ Kac-Moody algebras. Then, I use the FFR to unravel the embedding structure of the Verma modules of the ECFT with a $W sb3$ algebra. This embedding structure is expressed through a set of intertwining diagrams, which in turn, is used to compute …  Read more

The first part of this thesis includes a brief comparison between electric motors and hydraulic actuators for high performance robotics applications. Hydraulic actuators with fast valves are shown to be superior because of their large torque to mass ratios and their extended bandwidth. One such hydraulic actuator is characterized and its highly nonlinear dynamics are modeled and identified. A simulator implementing this dynamic model is shown to predict the system's behavior satisfyingly. A lead lag force controller that yields a large bandwidth and good accuracy is also designed. The second part is devoted to the modeling and control of an …  Read more

This thesis stages a meeting between the work of French philosopher Gilles Deleuze and the short fiction of Italian writer Italo Calvino. This meeting has as its subject the question of the human and the non-human. What forces make up the human? What assemblages of elements make up language, literature, subjectivity? And what does it mean that these forces come from outside the human at the same time as they create the human? Calvino is often accused of being an unemotional writer, lacking in human warmth. With this I agree completely. Calvino does lack human warmth because he allows non-human …  Read more

Poole, R. J. (Supervisor)  Read more

Using a Wittgensteinian approach to understanding, this thesis extends and challenges recent feminist discussions of the ethic of care as a gender-sensitive corrective to traditional moral theory. It elaborates a more complex understanding of the diversity and ambiguity of the ethical possibilities of caring than has been presented in earlier analyses. A brief introduction to the contemporary debate is followed by accounts of six different examples of caring practices, viz: caring attention, taking care of oneself, mothering, friendship, nursing and citizenship. The aim of this survey is to show that caring constitutes an intricate labyrinth of ethical possibilities, the understanding …  Read more

The goal of this study was to examine selective attention and distractibility within the visual modality in children with Down syndrome as compared to children of normal intelligence matched for mental age. Selective attention was defined as the children's abilities to identify and respond to a target stimulus on a forced choice reaction time task. Distractibility was considered to be the extent to which the children's performances on the task were interfered with by extraneous stimuli in the visual field. Conditions on the task varied with regard to the presence or absence and location (close and far) of distracting stimuli …  Read more

This thesis explores Roman Catholic and secular responses to sexual imagery in popular culture. The Catholic and socio-philosophical responses may be subdivided according to specific ideal types to elucidate the major ideological and ethical movements operative within these two hermeneutical traditions. I use the media luminary Madonna as a case study to illustrate the inadequacy of much that Catholic and secular cultural critics have written about religiously ambiguous and sexually provocative popular culture phenomena. Typically, secular critics neglect the religious implications of such phenomena, while Catholic critics overlook their ideological implications. I shall demonstrate both that hermeneutical exclusivity weakens the …  Read more

Time-resolved x-ray scattering has been used to study the kinetics of polymorphic crystallization of amorphous metals on time-scales varying from minutes to milliseconds. Using a high flux synchrotron beamline and fast position-sensitive detector system, simultaneous wide and small angle scattering patterns from the transforming material have been acquired in situ, with time-resolution as short as 3ms. A fast pyrometric temperature controller has been developed to change and regulate the sample temperature with microsecond response. Two alloys have been identified in which crystallization proceeds by thermally activated nucleation and growth of a single equilibrium phase at all observable transformation rates. Crystal …  Read more

Nineteen cultivars and fourteen breeding lines were evaluated for partial resistance to crown rust Puccinia coronata race 264. Multivariate statistical methods such as principal component and cluster analyses were employed to identify significant resistance parameters and to group oat genotypes with similar rust resistance characteristics. This involved two separate investigations consisting of two experiments each, the first experiment conducted under field conditions and the second conducted under growth bench conditions. From both of the investigations a group of oat genotypes with high partial resistance to P. coronata race 264 was obtained. These are OA 712-17, OA 712-33, Glen, Woodstock, QO …  Read more

This study involves the development and evaluation of an in-line melt rheometer (ILR) for use in process control. The ILR consists of a rotating drum, which is positioned directly in the main process flow channel. The drum creates a shear deformation in a zone formed between the drum and the channel wall. A method to correct for the effects of pressure flow superposed on the shear deformation was developed. The problems associated with sample renewal and temperature control in the shearing zone were explored with the help of simulations. The ILR's sensitivity to processing conditions was documented, and its accuracy …  Read more

A field lysimeter experiment was conducted on a sandy loam soil during the growing seasons of 1989 and 1990. The experiment tested the effects of four water table treatments on soybean (Glycine max) yields. The water table depths were 40, 60, 80, and 100 cm in depth. Yields were measured in terms of: total seed mass per plant, number of seeds per plant, number of pods per plant, number of seeds per pod, and speed protein content at harvest. The water management simulation model DRAINMOD, was used to develop irrigation and drainage strategies for soybean production. Three water table management …  Read more

The purpose of this study was to determine how one organization from the private sector managed the socialization and development of its middle management personnel at the growth career life cycle stages of its managers: recruitment and hiring, entry-level, mid-career, and the retirement stage. The organization studied was a Quebec based retail chain composed of twenty stores located in Quebec and Ontario. The findings indicated that there was a discrepancy between what the organization stated it was doing and what its middle management perceived was actually occurring. In three out of the five career life cycle stages, as described in …  Read more

In the ideology of sentimentalism, physical sensation integrates the parts of the body into a whole, and the fragmented members of the body politic into a social community. However, intense pain is always an individual experience. It not only isolates us from other people, but is also isolates us from our own bodies: pain renders our bodies out of control. Moreover, pain attacks our very notion of self by threatening to render us unconscious, and unable to perceive that self. This complex of problems became especially acute for late eighteenth-century writers, as they tried to reconcile their sympathy for the …  Read more

The overriding theme of this thesis concerns the level of antitrust enforcement within the U.S. airline industry by the agencies entrusted with this task. After a brief Introduction, Chapter I will examine whether concentration within the U.S. airline industry is a natural phenomenon or an ordinary monopoly/oligopoly resulting from the behaviour of competitors. In concluding that a natural monopoly/oligopoly does not exist, Chapter II will analyse the policy being antitrust enforcement in the industry. Chapter III will then use the implementation of S 408 of the Federal Aviation Act (FAA) by the Department of Transportation (DOT) as an example of …  Read more

The kinetics of copper etching were studied using a ferric chloride-hydrochloric acid etchant in a stirred-tank reactor. At a constant acid molarity of about 0.84 and FeCl$ sb3$ concentrations varying from 0 to 3 M, the etch rate was found to reach a maximum at about 2 M FeCl$ sb3$. The use of a ferric nitrate-nitric acid solution yielded similar results but substantially reduced etch rates. Since the nitrate ion is essentially non-complexing with the ferric ion, the presence of chloro complexes of the ferric ion in FeCl$ sb3$-HCl etchant solutions was investigated. The FeCl$ sb2 sp+$ and FeCl$ sb3 …  Read more

A method of minimizing the total active disc area, required for the removal of soluble biochemical oxygen demand (SBOD), by a multi-stage rotating biological contactor (RBC) operating steady-state is proposed. Both deterministic and stochastic inputs are considered. Total active disc area and the number of RBC stages are optimized for the deterministic case, and are then incorporated into a risk-based method of assigning per-stage active disc areas. The risk of the final stage SBOD exceeding a fixed effluent standard is evaluated by taking into account the variable nature of the influent flowrate and SBOD concentration. Bivariate normal, lognormal and shifted …  Read more