Prediction of chlorine and THMs concentration profile in bulk drinking water distribution systems from laboratory data

Nearly all drinking water distribution systems experience a "natural" reduction of disinfection residuals. The most frequently used disinfectant is chlorine, which can decay due to reactions with organic and inorganic compounds in the water and by liquid/solids reaction with the biofilm, pipe walls and sediments. Usually levels of 0.2-0.5 mg/L of free chlorine are required at the point of consumption to maintain bacteriological safety. Higher concentrations are not desirable as they present the problems of taste and odour and increase formation of disinfection by-products. It is usually a considerable concern for the operators of drinking water distribution systems to manage chlorine residuals at the "optimum level", considering all these issues. This paper describes how the chlorine profile in a drinking water distribution system can be modelled and optimised on the basis of readily and inexpensively available laboratory data. Methods are presented for deriving the laboratory data, fitting a chlorine decay model of bulk water to the data and applying the model, in conjunction with a simplified hydraulic model, to obtain the chlorine profile in a distribution system at steady flow conditions. Two case studies are used to demonstrate the utility of the technique. Melbourne's Greenvale-Sydenham distribution system is unfiltered and uses chlorination as its only treatment. The chlorine model developed from laboratory data was applied to the whole system and the chlorine profile was shown to be accurately simulated. Biofilm was not found to critically affect chlorine decay. In the other case study, Sydney Water's Nepean system was modelled from limited hydraulic data. Chlorine decay and trihalomethane (THM) formation in raw and treated water were measured in a laboratory, and a chlorine decay and THM model was derived on the basis of these data. Simulated chlorine and THM profiles agree well with the measured values available. Various applications of this modelling approach are also briefly discussed.

Prediction of chlorine and trihalomethanes concentration profile in bulk drinking water distribution systems from laboratory data

Nearly all drinking water distribution systems experience a "natural" reduction of disinfection residuals. The most frequently used disinfectant is chlorine, which can decay due to reactions with organic and inorganic compounds in the water and by liquid/solids reaction with the biofilm, pipe walls and sediments. Usually levels of 0.2-0.5 mg/L of free chlorine are required at the point of consumption to maintain bacteriological safety. Higher concentrations are not desirable as they present the problems of taste and odour and increase formation of disinfection by-products. It is usually a considerable concern for the operators of drinking water distribution systems to manage chlorine residuals at the "optimum level", considering all these issues. This paper describes how the chlorine profile in a drinking water distribution system can be modelled and optimised on the basis of readily and inexpensively available laboratory data. Methods are presented for deriving the laboratory data, fitting a chlorine decay model of bulk water to the data and applying the model, in conjunction with a simplified hydraulic model, to obtain the chlorine profile in a distribution system at steady flow conditions. Two case studies are used to demonstrate the utility of the technique. Melbourne's Greenvale-Sydenham distribution system is unfiltered and uses chlorination as its only treatment. The chlorine model developed from laboratory data was applied to the whole system and the chlorine profile was shown to be accurately simulated. Biofilm was not found to critically affect chlorine decay. In the other case study, Sydney Water's Nepean system was modelled from limited hydraulic data. Chlorine decay and trihalomethane (THM) formation in raw and treated water were measured in a laboratory, and a chlorine decay and THM model was derived on the basis of these data. Simulated chlorine and THM profiles agree well with the measured values available. Various applications of this modelling approach are also briefly discussed.

Clarifying the Effort-Reward Imbalance Model : the role of personality

The thesis aimed to identify the sources of stress experienced by a sample of Australian police officers. It was guided by the Effort-Reward Imbalance Model, augmented with Type A personality components. The findings support the research model and suggest that interventions to reduce stress should focus on reward and recognition.

An analysis on human personality and hotel web design : a Kohonen network approach

Having an eye catching and attractive website could help hotels to compete in the vigorous online market. This study attempts to examine the relationship between human personality and the web design preferences. Kohonen Networks were adopted to cluster people with similar personality characteristics and identify their differences on web design preferences. Empirical results indicated people with similar personality traits have similar design preferences. For example, to attract those who got high scores in agreeableness, conscientiousness and openness but low score in neuroticism, a web page should start with a language selection page with introductory movie, one large image on the web page showing hotel interior design with hotel guest in the photo, and with background music.

Towards discovery of influence and personality traits through social link prediction

Estimation of a person’s influence and personality traits from social media data has many applications. We use social linkage criteria, such as number of followers and friends, as proxies to form corpora, from popular blogging site Livejournal, for examining two two-class classification problems: influential vs. non-influential, and extraversion vs. introversion. Classification is performed using automatically-derived psycholinguistic and mood-based features of a user’s textual messages. We experiment with three sub-corpora of 10000 users each, and present the most effective predictors for each category. The best classification result, at 80%, is achieved using psycholinguistic features; e.g., influentials are found to use more complex language, than non-influentials, and use more leisure-related terms.

Profile of position movement demands in elite junior Australian rules footballers

This study investigated the positional movement patterns in elite junior Australian Football (AF). Thirty players (17.1 ± 0.9 years) participating in this study were tracked over seven home games of the regular 2006 Victorian junior (Under 18) league season. Using lapsed-time video analysis, each position for an entire match was videotaped on three separate occasions over the course of the season. Data analysed included the number of individual efforts, duration and frequency of efforts; distance and percentage time for the classifications of standing, walking jogging, running and sprinting. Results showed that the midfield position travelled the greatest distance (4173 ± 238 m per quarter; p < 0.05; ES = .94) whilst the full forward/full back travelled the least (2605 ± 348 m per quarter, p < 0.05, ES = 1.21). For all positions, walking or jogging accounted for the greatest number of efforts (45-55%), conversely running and sprinting accounted for 5-13% of match efforts. The majority of efforts across all classifications were between 0-3.99 s. The data from this study provides further evidence that AF is an intermittent sport characterised by high intensity movements separated by low intensity movements at a ratio of one high intensity effort every 12-40 s. However, careful interpretation of the data is required when training junior AF players for specific positions, given the specific group studied.

The association between parental personality patterns and internalising and externalising behaviour problems in children and adolescents

Background:  This study investigated the relationship between parental personality patterns and internalising and externalising behaviour problems in a clinically referred sample of children (aged 4–8) and adolescents (aged 12–18).

Methods:  Data from families involved in two clinical trials in Victoria, Australia were analysed (n = 59). Families were administered the Millons Clinical Multiaxial Inventory—III (MCMI-III) which reports personality patterns consistent with Axis II disorder and an Achenbach measure of mental health as appropriate to child's age (Child Behavior Checklist (CBCL), Youth Self-Report (YSR), or Adult Self-Report (ASR)). Relationships between internalising and externalising behaviour problems, and parental personality patterns were examined via correlation and regression analyses.

Results:  The study found a positive correlation between parental borderline, paranoid, and avoidant personality patterns, and child and adolescent externalising behaviour problems. The relationships were generally stronger for adolescents than for children. However, no relationship was observed between parental personality patterns and internalising behaviour problems.

Conclusions:  These findings underline the importance of clinical assessment of the family ecology as a whole—including the interaction between parental personality patterns and child and adolescent behaviour and emotional problems. These findings contribute to the understanding of developmental risk factors for child and adolescent mental health and the transmission of psychopathology across generations.

Working around a contested diagnosis : borderline personality disorder in adolescence

This discourse analytic study sits at the intersection of everyday communications with young people in mental health settings and the enduring sociological critique of diagnoses in psychiatry. The diagnosis of borderline personality disorder (BPD) is both contested and stigmatized, in mental health and general health settings. Its legitimacy is further contested within the specialist adolescent mental health setting. In this setting, clinicians face a quandary regarding the application of adult diagnostic criteria to an adolescent population, aged less than 18 years. This article presents an analysis of interviews undertaken with Child and Adolescent Mental Health Services (CAMHS) clinicians in two publicly funded Australian services, about their use of the BPD diagnosis. In contrast with notions of primacy of diagnosis or of transparency in communications, doctors, nurses and allied health clinicians resisted and subverted a diagnosis of BPD in their work with adolescents. We delineate specific social and discursive strategies that clinicians displayed and reflected on, including: team rules which discouraged diagnostic disclosure; the lexical strategy of hedging when using the diagnosis; the prohibition and utility of informal ‘borderline talk’ among clinicians; and reframing the diagnosis with young people. For clinicians, these strategies legitimated their scepticism and enabled them to work with diagnostic uncertainty, in a population identified as vulnerable. For adolescent identities, these strategies served to forestall a BPD trajectory, allowing room for troubled adolescents to move and grow. These findings illuminate how the contest surrounding this diagnosis in principle is expressed in everyday clinical practice.