494 research outputs found

    Management of water distribution systems in PDA conditions using isolation valves: case studies of real networks

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    Abstract The current paper reports on a case study investigating water distribution system management in emergency conditions when it is necessary to seal off a zone with isolation valves to allow repair. In these conditions, the pressure-driven analysis (PDA) is considered to be the most efficient approach for the analysis of a water distribution network (WDN), as it takes into account whether the head in a node is adequate to ensure service. The topics of this paper are innovative because, until now, previous approaches were based on the analysis of the network behaviour in normal conditions. In emergency conditions, it is possible to measure the reliable functioning of the system by defining an objective function (OF) that helps to choose the optimal number of additional valves in order to obtain adequate system control. The OF takes into account the new network topology by excluding the zone where the broken pipe is located. The results show that the solution did not improve significantly when the number of valves reached a threshold. The procedure applied to other real case studies seems to confirm the efficiency of the methodology even if further examination of other cases in different conditions is necessary

    Identification of Measurement Points for Calibration of Water Distribution Network Models

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    AbstractMuch importance is given to determining the input data for water distribution system networks, particularly with regard to urban networks, because the design and the management of WDS are based on a verification model. Good calibration of models is required to obtain realistic results. This is possible by the use of a certain number of measurements: flow in pipes and pressure in nodes. The purpose of this paper is to analyze a new model able to provide guidance on the choice of measurement points to obtain the site data. All analyses are carried out firstly on literature networks and then on a real network using a new approach based on sensitivity matrices

    Identification of leakages by calibration of WDS models

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    Open Access journalCopyright © 2013 The Authors. Published by Elsevier Ltd.12th International Conference on Computing and Control for the Water Industry, CCWI2013Leakage detection is critical for the proper management of water distribution systems (WDS). This paper proposes a leak detection approach based on a Bayesian calibration method. The methodology uses a newly formulated index, μ, which takes into account the variation of roughness in pipes between the calibrated models with and without leaks. Case studies, which use literature networks, are presented to demonstrate how the approach can be used in identifying pipes with losses. The approach starts with a calibration method followed by the analysis of sensitivity matrices. The approach proved to be effective in finding leaks, but the results depend crucially on the number and quality of the observed data.European CommissionEuropean Social FundRegion of Calabri

    Model calibration as a tool for leakage identification in WDS: A real case study

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    16th Water Distribution System Analysis Conference, WDSA2014 — Urban Water Hydroinformatics and Strategic PlanningCopyright © 2014 The Authors. Published by Elsevier Ltd.Water leakage detection is important for a proper management of water distribution systems (WDS). This paper proposes the application of the leak detection approach based on a new Bayesian calibration methodology. The methodology uses a new developed index μ, which takes into account the difference in roughness values in pipes of the calibrated models with and without leaks. The case study is referred to a real network and is presented to demonstrate how the approach can be used in identifying pipes with losses. The approach starts with the UNINET calibration method followed by the analysis of sensitivity matrices. The case study proves that the approach is effective in finding leaks in real networks, but the results depend on the quality of the observed data

    Caracterización petrológica y geoquímica de las rocas plutónicas de la Sierra de La Aguada, Provincia de San Luis, Argentina: Implicaciones genéticas con el arco magmático Famatiniano

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    This study presents a synthesis on the geology of the crystalline complex that constitute the Sierra de la Aguada, San Luis province, Argentine, from an approach based on field relations, petrologic and structural features and geochemical characteristic. This mountain range exposes a basement dominated by intermediate to mafic calcalkaline igneous rocks and peraluminous felsic granitoids, both emplaced in low to medium grade metamorphic rocks stabilized under low amphibolite facies. All this lithological terrane has been grouped in the El Carrizal-La Aguada Complex. Field relations, petrographic characterization and geochemical comparison of the plutonic rocks from the study area with those belonging to the Ordovician Famatinian suit exposed in the Sierra Grande de San Luis, suggest a genetic and temporal relation linked to the development of the Famatinian magmatic arc.El presente trabajo expone una síntesis de la geología que comprende al complejo cristalino que constituye la Sierra de La Aguada, provincia de San Luis, Argentina, desde un enfoque basado en las relaciones de campo, los rasgos petrológico-estructurales y las características geoquímicas. Dicha serranía expone un basamento dominado por rocas plutónicas intermedias-máficas de afinidad calcoalcalina y granitoides félsicos peraluminosos, en conjunto intruidas en metamorfitas de bajo a medio grado metamórfico estabilizadas en condiciones de facies de anfibolita. Todo el conjunto litológico ha sido agrupado dentro del denominado complejo El Carrizal-La Aguada. El análisis de las relaciones de campo, la petrografía y la comparación de las características geoquímicas de las rocas plutónicas del área estudiada y aquellas pertenecientes a la suite ordovícica Famatiniana expuestas en la Sierra Grande de San Luis, sugiere una posible relación genética-temporal vinculada al desarrollo del arco magmático Famatiniano

    Once-monthly paliperidone palmitate in recently diagnosed and chronic non-acute patients with schizophrenia

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    OBJECTIVE: To explore the treatment response, tolerability and safety of once-monthly paliperidone palmitate (PP1M) in non-acute patients switched to oral antipsychotics stratified by time since diagnosis as recently diagnosed (3 years). RESEARCH DESIGN AND METHODS: Post-hoc analysis of a prospective, interventional, single-arm, multicentre, open-label, 6-month study performed in 233 recently diagnosed and 360 chronic patients. MAIN OUTCOME MEASURES: The proportion achieving treatment response (defined as >/=20% improvement in Positive and Negative Syndrome Scale [PANSS] total score from baseline to endpoint) and maintained efficacy (defined as non-inferiority in the change in PANSS total score at endpoint [Schuirmann's test]). RESULTS: 71.4% of recently diagnosed and 59.2% of chronic patients showed a >/=20% decrease in PANSS total score (p=0.0028 between groups). Changes in PANSS Marder factors, PANSS subscales, and the proportion of patients with a Personal and Social Performance scale (PSP) total score of 71-100 were significantly greater in recently diagnosed compared with chronic patients. PP1M was well tolerated, presenting no new safety signals. CONCLUSION: These data show that recently diagnosed patients treated with PP1M had a significantly higher treatment response and improved functioning, as assessed by the PSP total score, than chronic patients

    Validation of the Italian version of the "Mood Disorder Questionnaire" for the screening of bipolar disorders.

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    The study measured the accuracy of the Italian version of the Mood Disorder Questionnaire (MDQ) as a screening instrument for bipolar disorders in a psychiatric setting. Methods: 154 consecutive subjects attending the Division of Psychiatry of the University of Cagliari (Italy), were screened for bipolar disorders using the Italian translation of the MDQ, and diagnostically interviewed with the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID) by physicians. Results: On the basis of the SCID: 51 (33.1%) received a diagnosis of bipolar or schizoaffective bipolar type disorders, 63 (40.9%) were diagnosed as having at least one psychiatric disorder in Axis I (other than bipolar or schizoaffective bipolar type disorders), whilst 40 (25.9%) were unaffected by any type of psychiatric disorder. MDQ showed a good accuracy for bipolar or schizoaffective bipolar type disorders: the cut-off 4 had sensitivity 0.90 and specificity 0.58; the cut-off 5 had sensitivity 0.84 and specificity 0.70; and the cut-off 6 had sensitivity 0.76 and specificity 0.86. The accuracy for bipolar II disorders was sufficient but not excellent: the cut-off 4 had sensitivity 0.80 and specificity 0.45; the cut-off 5 had sensitivity 0.70 and specificity 0.55; and the cut-off 6 had sensitivity 0.55 and specificity 0.65. Conclusion: Our results seem to indicate a good accuracy of MDQ, and confirm the results of recent surveys conducted in the USA. Moreover the instrument needs to be validated in other settings (e.g. in general practice)

    Assessing feasibility and acceptability of web-based enhanced relapse prevention for bipolar disorder (ERPonline): a randomized controlled trial

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    Background: Interventions that teach people with Bipolar Disorder (BD) to recognise and respond to early warning signs of relapse are NICE recommended but implementation in clinical practice is poor. Objective: This study tests the feasibility and acceptability of a randomised controlled trial to evaluate an online enhanced relapse prevention intervention (ERPonline), and reports preliminary evidence of effectiveness. Methods: Single blind, parallel primarily online randomised controlled trial (n=96) over 48 weeks comparing ERPonline plus usual treatment to waitlist (WL) control plus usual treatment for people with BD recruited through National Health Services, voluntary organisations, and media. Randomisation was independent, minimised on number of previous episodes (<8,8-20,21+). Primary outcomes were feasibility and acceptability assessed by rates of study recruitment and retention, levels of intervention use, adverse events and participant feedback. Process and clinical outcomes were assessed by telephone and online and compared using linear models with intention-to-treat analysis. Results: Two hundred and eighty people registered interest online, from which ninety-six met inclusion criteria, consented and were randomised (49 to WL, 47 to ERPonline) over seventeen months, with 80% retention in telephone and online follow up, except week 48 online (76%). Acceptability was high for both ERPonline and trial methods. ERPonline cost approximately £19,340 to create, and £2176 per year to host and maintain the site. Qualitative data highlighted the importance of the relationship users have with online interventions and how this is created as an extension of the relationship with the humans perceived as offering and supporting its use. Differences between the group means suggested that access to ERPonline was associated with: a more positive model of bipolar disorder at 24 (10.70 (0.90-20.5 95%CIs)) and 48 weeks (13.1 (2.44-23.93 95%CIs)); increased monitoring of early warning signs of depression at 48 weeks (-1.39 (-2.61, -.163 95%CIs)) and of (hypo)mania at 24 (-1.72 (-2.98, -0.47 95%CIs)) and 48 weeks (-1.61 (-2.92, -0.30 95%CIs)), compared to WL. There was no evidence of impact of ERPonline on clinical outcomes or medication adherence, but relapse rates across both arms were very low (15%) and the sample remained high functioning throughout. One person died by suicide prior to randomisation. Five people in ERPonline and six in WL control reported ideas of suicide or self-harm during the study. None were deemed study related by an independent Trial Steering Committee. Conclusions: ERPonline offers a cheap accessible option for people seeking ongoing support following successful treatment. However, given high functioning and low relapse rates in this study, testing clinical effectiveness for this population would require very large sample sizes. Building in human support to use ERPonline should be considere
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