A comprehensive and well tested energy balance for water supply systems

This paper presents a novel energy balance scheme and performance indicators for assessing energy efficiency in water supply systems. This assessment consists of a three-step procedure: system characterisation and data collection, energy balance calculation and energy performance indicators assessment. The main innovation is the integrated approach between energy and water balances allowing the quantification of energy inefficiencies directly associated with water losses. Comprehensive energy performance indicators can be calculated by utilities with different maturity levels allowing a fair comparison of energy efficiency between systems with different layouts and operational schemes. This energy balance scheme has been applied by 17 water utilities in Portugal. Results have shown that systems provide more than twice the minimum energy necessary to supply their consumers and, consequently, there is a significant energy saving potential: 40% through water loss reduction, 30% for changes in network operation and layout and 30% for pump inefficiency reduction.     

Magnesium alloy defectology AZ91D high‐pressure die cast and influence on the fatigue behaviour

The fatigue results of a high‐pressure die cast of AZ91D magnesium alloy revealed the presence of different types of casting defects, which account for the large scattering in the number of cycles until failure. In this paper, this magnesium alloy has been analysed, and in an effort to reproduce the same surface and material conditions exhibited in automotive service components, the fatigue test samples were manufactured using a die that employs the same casting process and equipment. To examine the fracture surface of all the fatigue tests, a scanning electron microscope was used, and the source of the failure, so as to relate fatigue life with casting defect type, was identified. Five casting defect types that influence the fatigue behaviour were observed and classified: (a) isolated pores (blowholes), (b) micro‐porosity areas, (c) circular shrinkage cavities associated with the contraction and geometry of the casted specimen, (d) surface burrs associated with the die‐casting mould and (e) the presence of oxides or inclusions.     

Fatigue design of wire-wound pressure vessels using ASME-API 579 procedure

The wire winding of high pressure vessels is a technique usually applied to introduce initial compressive stresses in the inner core of the vessel, with the aim to improve the fatigue life under cyclic pressure conditions. In this work, the procedure followed to calculate the number of design cycles is presented, using the fracture mechanics approach and the structural integrity concepts. In particular, the API 579-1/ASME FFS-1 procedure has been used to analyse the structural integrity of the vessel through the crack propagation stage. Starting from a postulated internal semi-elliptical crack the number of design cycles is determined, the flaw aspect ratio is updated and the structural integrity of the cracked vessel is evaluated using the Failure Assessment Diagram (FAD). Different propagation laws, which take into account for negative stress intensity ratio factors R = K_min/K_max < 0, are reviewed, because of their high influence on the fatigue life of wire-wound vessels. In addition, this paper presents a number of useful expressions to calculate the stress intensity factor (SIF) for internal semi-elliptical cracks in wire-wound pressure vessels, in order to carry out the numerical integration of the number of cycles, updating the flaw aspect ratio, during the fatigue crack growth.     

Association of thin basement membrane nephropathy with hypercalciuria, hyperuricosuria and nephrolithiasis

BACKGROUND: Familial persistent microhematuria with normal renal function is the most common presentation of thin basement membrane nephropathy (TBMN). Gross hematuria episodes and loin pain attacks are other manifestations of the disease. On the other hand, it has been shown that hypercalciuria (HC) and hyperuricosuria (HU) can produce both gross or microscopic non-glomerular hematuria, in addition to their role in renal stone formation. METHODS: We studied the prevalence of HC, HU and nephrolithiasis in a group of 27 biopsy-proven TBMN as well as in 19 non-biopsied first-degree relatives with persistent microhematuria and 25 first-degree relatives without microhematuria. A group of 27 patients with IgA nephropathy (IgAN) and persistent microhematuria, and another group of 20 healthy subjects without known renal diseases were selected as control groups. RESULTS: Ten (37%) patients with TBMN and 8 (42%) relatives with microhematuria showed HC and/or HU at presentation; relatives without microhematuria, IgAN patients and normal controls showed a significantly lower prevalence of HC and HU. The prevalence of previous nephrolithiasis among TBMN patients (25%) was significantly higher than in IgAN patients (3%; P < 0.05). Family history of nephrolithiasis was recorded in 14 (51%) of the 27 TBMN families, in contrast with 2 of 27 (7%) with IgAN and 1 of 20 (5%) in normal controls (P < 0.05). The prevalence of nephrolithiasis, gross hematuria bouts and loin pain episodes among TBMN patients and microhematuric relatives showing HC and/or HU at presentation (44%, 44% and 27%, respectively) were significantly higher than those of TBMN patients and microhematuric relatives with normal calcium and uric acid urinary excretions (10%, 7% and 3%, respectively; P < 0.05). At the end of follow-up (8.8+/-4.1 years in TBMN patients and 9.1+/-4.2 years in relatives with microhematuria), all the cases maintained normal renal function. CONCLUSIONS: We found a high prevalence of HC, HU, and nephrolithiasis among TBMN patients and relatives with microhematuria. Our study also shows a significant relationship between the presence of HC and/or HU and the prevalence of nephrolithiasis, gross hematuria bouts and loin pain episodes.     

Expression and function of CTLA-4 in Th1 and Th2 cells

CTLA-4 is expressed on T cells after activation and shares homology with the CD28 costimulatory receptor. In contrast to CD28, CTLA-4 is thought to be a negative regulator of T cell activation. Cross-linking of CTLA-4 during activation of peripheral T cells reduces IL-2 production and arrests T cells in G1. Much less is known about the function of CTLA-4 in differentiated T cells. We have investigated the expression and function of CTLA-4 in established Th1 and Th2 clones and in bulk populations of Th1 and Th2 cells freshly derived in vitro from TCR transgenic splenocytes. We found that CTLA-4 was induced under similar conditions and with similar kinetics following activation of both Th1 and Th2 clones. However, CTLA-4 expression was much higher in Th2 than Th1 clones and lines. This was confirmed by flow cytometry, confocal microscopy, and Northern blot analysis. The ratio of surface to intracellular expression of CTLA-4 and its rate of endocytosis were similar in Th1 and Th2 clones. Inhibition of binding of CTLA-4 to its ligands using soluble anti-CTLA-4 mAb during stimulation with Ag increased the production not only of IL-2 by Th1 clones, but also that of IL-3 and IFN-gamma by Th1 clones and of IL-3, IL-4, IL-5, and IL-10 by Th2 clones. In contrast, when anti-CTLA-4 was coimmobilized with anti-CD3 and anti-CD28 mAbs, a decrease in the production of multiple cytokines was observed. We conclude that CTLA-4 can function to suppress the production of cytokines produced by both Th1 and Th2 cells.     

Nutritional characterization of produced fish for human consumption in Bucaramanga, Colombia

This research involves the nutritional characterization of the most commonly cultivated fish in the region. The species under study were: Rainbow trout (Salmo gairdnerii), tilapia roja (Oreocliromis sp), cachama blanca (Piaractus brachypomus), bocachico (Prochilodus reticulatus magdalenae) and catfish (Pseudoplatystoma faciatum). A sea fish, coho Salmon (Oncorhynchus kisutch), was used as reference because it is the imported species most used in the region, and it also contains n-3 fatty acids. For each fish sample moisture, ash, protein content, total fat, minerals (iron, calcium and phosphorous) and a fatty acid profile were determined. Results show a total protein content in between 16.4 and 22.6 g/100 g fillet for fresh water fish. Total fat amounts for trout are the highest (8.1 g/100 g fillet), while catfish has the lowest fat content (0.4 g/100 g fillet). Trout was found to be the most important source of n-3 fatty acids (EPA+DHA) and phosphorous, with values ranging from 0.25% to 0.52%, and 250 to 346 mg/100 g fillet, respectively. Catfish and trout exhibited the highest iron content, with values ranging from 3 to 6mg/100 g fillet. Salmon, on the other hand, showed a high n-3 fatty acid content of 1.16% to 2.25%, when compared to fresh water fish. Calcium content is low in all species under scrutiny. Fresh water fish, other than trout, show no significant amount of n-3 fatty acids. However, all of them are a good source of protein. The obtained results allowed to determine the profile of oily acids of produced fish for human consumption in the region, demonstrating that the trout is the species with major quantity of oily acids n-3 specially DHA and of the minerals the phosphorus. Other species (kinds) catfish, bocachico, tilapia and cachama, are not a source of oily acids n-3, but they are an important source of protein.     

Validation of digital photographs, as a tool in 24-h recall, for the improvement of dietary assessment among rural populations in developing countries

ABSTRACT: BACKGROUND: Improvement of traditional methods for dietary assessment is necessary, especially in rural areas where it is more difficult to succeed with self-reporting methods. This study presents and validates a method for improving accuracy when measuring food and nutrient intake of individuals in rural areas. It is called the "Food photography 24-h recall method" (FP 24-hR) and is a modified 24-h recall with the addition of a digital food photography record and a photo atlas. METHODS: The study was carried out in a rural area in the tropical region of Bolivia; 45 women participated. Validation of the method was made by comparing it with a reference method, the Weighed Food Record (WFR). During the FP 24-hR, digital photographs were taken by the subjects of all food consumed during a day and a 24-h recall questionnaire was conducted by an interviewer. An estimate of the amount of food consumed was made using a photo atlas and the photographs taken by the subjects. For validation, comparison was made between the calculations, by both methods, of the levels of food, and nutrient, intake. RESULTS: The comparison was made in 10 food categories; most of which were somewhat underestimated from [MINUS SIGN]2.3% (cassava) to [MINUS SIGN]6.8% (rice), except for beverages (+1.6%) and leafy vegetables (+8.7%), which were overestimated. Spearman's correlation coefficients were highly significant (r from 0.75 for eggs to 0.98 for potato and cassava). Nutrient intakes calculated with data from both methods showed small differences from -0.90% (vitamin C) to -5.98% (fat). Although all nutrients were somewhat underestimated, Pearson[ACUTE ACCENT]s coefficients are high (>0.93 for all) and statistically significant. Bland Altman analysis showed that differences between both methods were random and did not exhibit any systematic bias over levels of food and nutrient intake, with acceptable 95% limits of agreement. CONCLUSION: The FP 24-hR exhibits acceptable differences when compared with a WFR, digital photos are useful as a memory aid for the subjects during 24-h recall and as an estimation tool. The method is suitable for assessing dietary intake among rural populations in developing countries.