Quantifying measuring errors of new residential water meters considering different customer consumption patterns

Water meter measuring errors vary depending on the water flow rate. The difference between water actually consumed and registered by a meter will differ depending on how water consumption is distributed by flow rates. Published studies assessing the performance of new residential meters have only analysed the error curves of the meters without calculating the influence that consumption patterns have on their field performance. In most cases, research has been limited to analysing compliance with published standards. This work presents an evaluation of the actual commercial losses to be expected considering the consumption characteristic of domestic users. Several types of residential meters have been tested and the error curves obtained have been combined with measured consumption patterns of domestic users. As a result, this paper provides information about the order of magnitude of the initial measuring error as a function of the residential meter model and user characteristics.The translation of this paper was funded by the Universitat Politecnica de Valencia, Spain.Arregui De La Cruz, F.; Balaguer Garrigós, M.; Soriano Olivares, J.; García-Serra García, J. (2015). Quantifying measuring errors of new residential water meters considering different customer consumption patterns. Urban Water Journal. 13(5):463-475. doi:10.1080/1573062X.2014.993999S463475135American Water Works Association (AWWA), 1999. Water Meters - Selection, Installation, Testing, and Maintenance: Manual of Water Supply Practices (M6). Denver, CO: American Water Works Association.American Water Works Association (AWWA), 2009. Water Audits and Loss Control Programs: AWWA Manual M36. Denver, CO: American Water Works Association.Arregui, F.J., CabreraJr, E., and Cobacho, R., 2006a. Integrated water meter management. London: IWA Publishing.Arregui, F. ., Cabrera, E., Cobacho, R., & García-Serra, J. (2006). Reducing Apparent Losses Caused By Meters Inaccuracies. Water Practice and Technology, 1(4). doi:10.2166/wpt.2006.093Arregui, F.J., Martinez, B., Soriano, J., and Parra, J.C., 2009. Tools for improving decision making in water meter management. Proceedings of the 5th IWA Water Loss Reduction Specialist Conference (pp. 225–232). Cape Town, South Africa.Barfuss, S.L., Johnson, M.C., and Neilsen, M.A., 2011. Accuracy of in-service water meters at low and high flow rates. Denver, CO: Water Research Foundation, Denver.Blokker, E. J. M., Vreeburg, J. H. G., & van Dijk, J. C. (2010). Simulating Residential Water Demand with a Stochastic End-Use Model. Journal of Water Resources Planning and Management, 136(1), 19-26. doi:10.1061/(asce)wr.1943-5452.0000002Bowen, P.T., Harp, J.F., Hendricks, J.E., and Shoeleh, M., 1991. Evaluating residential meter performance. Denver, CO: American Water Works Association Research Foundation.Bowen, P.T., Harp, J.F., Baxter, J.W., and Shull, R.D., 1993. Residential water use patterns. Denver, CO: American Water Works Association Research Foundation.Criminisi, A., Fontanazza, C. M., Freni, G., & Loggia, G. L. (2009). Evaluation of the apparent losses caused by water meter under-registration in intermittent water supply. Water Science and Technology, 60(9), 2373-2382. doi:10.2166/wst.2009.423DeOreo, W.B. and Mayer, P.W., 2013. Residential end uses of water study update. Denver, CO: Water Research Foundation.ISO 4064-3, 1993. Measurement of water flow in closed conduits - meters for cold potable water. Part 3: Test methods and equipment. Geneva: International Organization for Standardization.ISO 4064-1, 2005. Measurement of water flow in a fully charged closed conduit - meters for cold potable water and hot water. Part 1: Specifications. Geneva: International Organization for Standardization.Lievers, C. and Barendregt, A., 2009. Implementation of intervention techniques to decrease commercial losses for Ghana. Proceedings of the 5th IWA Water Loss Reduction Specialist Conference (pp. 490–496). Cape Town, South Africa.Male, J.W., Noss, R.R., and Moore, I.C., 1985. Identifying and Reducing Losses in Water Distribution Systems. Saddle River, NJ: Noyes Publications.Mayer, P.W., DeOreo, W.B., Opitz, E.M., Kiefer, J.C., Davis, W.Y., Dziegielewski, B., and Nelson, J.O., 1999. Residential End Uses of Water. Denver, CO: AWWA Research Foundation and American Water Works Association.Mutikanga, H. E., Sharma, S. K., & Vairavamoorthy, K. (2010). Assessment of apparent losses in urban water systems. Water and Environment Journal, 25(3), 327-335. doi:10.1111/j.1747-6593.2010.00225.xNeilsen, M. A., Barfuss, S. L., & Johnson, M. C. (2011). Off-the-shelf accuracies of residential water meters. Journal - American Water Works Association, 103(9), 48-55. doi:10.1002/j.1551-8833.2011.tb11531.xRichards, G. L., Johnson, M. C., & Barfuss, S. L. (2010). Apparent losses caused by water meter inaccuracies at ultralow flows. Journal - American Water Works Association, 102(5), 123-132. doi:10.1002/j.1551-8833.2010.tb10115.xRizzo, A. and Cilia, J., 2005. Quantifying meter under-registration caused by the ball valves of roof tanks (for indirect plumbing systems). Proceedings of the Leakage 2005 Conference, Halifax, Canada.Thornton, J., Sturm, R., and Kunkel, G., 2008. Water Loss Control. New York: McGraw-Hill.Woltmann, 2008. ITA. Valencia, Spain: Universitat PolitecnicaRetrieved from: http://www.ita.upv.es/software/presentacion-en.php.Yaniv, S., 2012. Reduction of apparent losses using the UFR (Unmeasured-flow reducer): Case studies. Proceedings of the 5th IWA Specialist Conference on Efficient Water Use and Management. Hague, The Netherlands.Yee, M. D. (1999). Economic analysis for replacing residential meters. Journal - American Water Works Association, 91(7), 72-77. doi:10.1002/j.1551-8833.1999.tb08666.

Pre-dialysis clinic attendance improves quality of life among hemodialysis patients

BACKGROUND: Although previous research has demonstrated that referral to pre-dialysis clinics is associated with favourable objective outcomes, the benefit of a pre-dialysis clinic from the perspective of patient-perceived subjective outcomes, such as quality of life (QOL), is less well defined. METHODS: A retrospective incident cohort study was conducted to determine if pre-dialysis clinic attendance was a predictor of better QOL scores measured within the first six months of hemodialysis (HD) initiation. Inclusion criteria were HD initiation from January 1 1998 to January 1 2000, diagnosis of chronic renal failure, and completion of the QOL questionnaire within six months of HD initiation. Patients receiving HD for less than four weeks were excluded. An incident cohort of 120 dialysis patients was identified, including 74 patients who attended at least one pre-dialysis clinic and 46 patients who did not. QOL was measured using the SF 36-Item Health Survey. Independent variables included age, sex, diabetes, pre-dialysis clinic attendance and length of attendance, history of ischemic heart disease, stroke, peripheral vascular disease, heart failure, malignancy, and chronic lung disease, residual creatinine clearance at dialysis initiation, and kt/v, albumin and hemoglobin at the time of QOL assessment. Bivariate and multivariate linear regression analyses were used to identify predictors of QOL scores. RESULTS: Multivariate analysis suggested that pre-dialysis clinic attendance was an independent predictor of higher QOL scores in four of eight health domains (physical function, p < 0.01; emotional role limitation, p = 0.01; social function, p = 0.01; and general health, p = 0.03), even after statistical adjustment for age, sex, residual renal function, kt/v, albumin, and co-morbid disease. Pre-dialysis clinic attendance was also an independent predictor of the physical component summary score (p = 0.03). CONCLUSIONS: We conclude that pre-dialysis clinic attendance favourably influences patient-perceived quality of life within six months of dialysis initiation

Quality of life and mortality from a nephrologist's view: a prospective observational study

<p>Abstract</p> <p>Background</p> <p>Although health-related quality of life (HRQOL) is a potential independent predictor of mortality, nephrologists have shown little interest in HRQOL with respect to mortality in chronic kidney disease (CKD). The aim of this article is to evaluate the impact of HRQOL on mortality in the elderly, who are likely to develop or already have CKD.</p> <p>Methods</p> <p>Among 1,000 randomly sampled participants aged more than 65 years (sourced from the Korean Longitudinal Study on Health and Ageing), 944 subjects were evaluated for HRQOL. HRQOL was assessed using a 36-item Short-Form health survey (SF36). A cumulative survival rate was calculated according to tertiles of SF36 scores and classified by the presence of CKD (estimated GFR <60 ml/min/1.73 m²).</p> <p>Results</p> <p>Among 944 subjects, 46.6% had CKD. CKD patients had lower total and physical component scores compared with subjects without CKD. The 3-year cumulative survival rate was 90.0% (non-CKD vs. CKD: 92.6% vs. 87.4%, <it>P </it>= 0.005 by log rank test). After adjusting for multiple variables, a reduced SF36 score (physical and mental components) was a strong predictor of all-cause mortality. Physical components were consistently able to predict mortality after CKD classification, but mental components were statistically significant only in the CKD group.</p> <p>Conclusion</p> <p>In addition to traditional risk factors of mortality, nephrologists should be aware of HRQOL as a predictor of mortality and should make efforts to improve HRQOL in CKD patients.</p

Quality of life assessed with the medical outcomes study short form 36-item health survey of patients on renal replacement therapy: A systematic review and meta-analysis

Objectives: The Medical Outcomes Study Short Form 36-Item Health Survey (SF-36) is the most widely used generic instrument to estimate quality of life of patients on renal replacement therapy. Purpose of this study was to summarize and compare the published literature on quality of life of hemodialysis (HD), peritoneal dialysis (PD), and renal transplant (RTx) patients. Methods: We used random-effects regression analyses to compare the SF-36 scores across treatment groups and adjusted this comparison for age and prevalence of diabetes using random-effects meta-regression analyses. Results: We found 52 articles that met the inclusion criteria, reporting quality of life of 36,582 patients. The unadjusted scores of all SF-36 health dimensions were not significantly different between HD and PD patients, but the scores of RTx patients were higher than those of dialysis patients, except for the dimensions Mental Health and Bodily Pain. Point differences between dialysis and RTx patients varied from 2 to 32. With adjustment for age and diabetes, the differences became smaller (point difference 2–22). The significance of the differences of both dialysis groups compared with RTx recipients disappeared for the dimensions Vitality and Social Functioning. The significance of the differences between HD and RTx patients disappeared on the dimensions Physical Functioning, Role Physical, and Bodily Pain. Conclusion: We conclude that dialysis patients have a lower quality of life than RTx patients, but this difference can partly be explained by differences in age and prevalence of diabetes. Keywords: hemodialysis, meta-analysis, peritoneal dialysis, quality of life, renal transplantation

Urban futures and the code for sustainable homes

Copyright © 2012 ICE Publishing Ltd. Permission is granted by ICE Publishing to print one copy for personal use. Any other use of these PDF files is subject to reprint fees.A 6?6 ha (66 000 m2) regeneration site, commonly referred to as Luneside East, is to be turned from a run down, economically under-achieving area of Lancaster, UK, into a new, distinctive, vibrant, sustainable quarter of the city. As a result several aspects of water planning for 350 new homes and 8000 m2 of workspace needed to be considered before any infrastructure investment was undertaken. This included assessment of the future capacity requirements (i.e. inflows and outflows) for water infrastructure (i.e. mains water supply, wastewater disposal, rainwater storage and stormwater disposal) much of which will be located underground. This paper looks at the implications of various water management strategies on the Luneside East site (e.g. water-efficient appliances, greywater recycling and rainwater harvesting) in line with current policy measures that focus on technology changes alone (e.g. the code for sustainable homes). Based on these findings this paper outlines some basic implications for technological resilience discussed in the context of four ‘world views’ – that is, the urban futures scenarios considered in this special issue. Conclusions are drawn as to how far this can take engineers, planners and developers in understanding and planning for resilient water infrastructure within a development like Luneside East

Defensive coping and health-related quality of life in chronic kidney disease: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Coping with the stresses of chronic disease is considered as a key factor in the perceived impairment of health related quality of life (HRQL). Little is known though about these associations in chronic kidney disease (CKD). The present study aimed to investigate the relationship of defensive coping and HRQL among patients in different CKD stages, after adjusting for psychological distress, sociodemographic and disease-related variables.</p> <p>Methods</p> <p>The sample consisted of 98 CKD patients, attending a university nephrology department. Seventy-nine (79) pre-dialysis patients of disease stages 3 to 4 and 19 dialysis patients were included. HRQL was assessed by the 36-item Short-Form health survey (SF-36), defensive coping by the Rationality/Emotional Defensiveness (R/ED) scale of the Lifestyle Defense Mechanism Inventory (LDMI) and psychological distress by the depression and anxiety scales of the revised Hopkins Symptom CheckList (SCL-90-R). Regression analyses were carried out to examine the association between SF-36 dimensions and defensive coping style.</p> <p>Results</p> <p>Patients on dialysis had worse scores on SF-36 scales measuring physical aspects of HRQL. In the fully adjusted analysis, a higher defensive coping score was significantly associated with a lower score on the mental component summary (MCS) scale of the SF-36 (worse mental health). In contrast, a higher defensive score showed a small positive association with the physical component summary (PCS) scale of the SF-36 (better health), but this was marginally significant.</p> <p>Conclusions</p> <p>The results provided evidence that emotional defensiveness as a coping style tends to differentially affect the mental and the physical component of HRQL in CKD. Clinicians should be aware of the effects of long-term denial and could examine the possibility of screening for defensive coping and depression in recently diagnosed CKD patients with the aim to improve both physical and mental health.</p

Should the poultry red mite Dermanyssus gallinae be of wider concern for veterinary and medical science?

The poultry red mite Dermanyssus gallinae is best known as a threat to the laying-hen industry; adversely affecting production and hen health and welfare throughout the globe, both directly and through its role as a disease vector. Nevertheless, D. gallinae is being increasingly implemented in dermatological complaints in non-avian hosts, suggesting that its significance may extend beyond poultry. The main objective of the current work was to review the potential of D. gallinae as a wider veterinary and medical threat. Results demonstrated that, as an avian mite, D. gallinae is unsurprisingly an occasional pest of pet birds. However, research also supports that these mites will feed from a range of other animals including: cats, dogs, rodents, rabbits, horses and man. We conclude that although reported cases of D. gallinae infesting mammals are relatively rare, when coupled with the reported genetic plasticity of this species and evidence of permanent infestations on non-avian hosts, potential for host-expansion may exist. The impact of, and mechanisms and risk factors for such expansion are discussed, and suggestions for further work made. Given the potential severity of any level of host-expansion in D. gallinae, we conclude that further research should be urgently conducted to confirm the full extent of the threat posed by D. gallinae to (non-avian) veterinary and medical sectors