Von Netzalter, Wasserverlusten und Schadensraten zur langfristigen Erneuerungsplanung

Die Planung bzw. Festlegung einer langfristigen Erneuerungsstrategie für Trinkwasserversorgungsanlagen ist ein oft diskutiertes Thema und grundsätzlich keine einfache Aufgabe. So gibt es zum Beispiel auf der einen Seite die technische Nutzungsdauer von Trinkwasserrohrleitungen, die unter anderem von der Materialwahl, dem Durchmesser und den Untergrundverhältnissen abhängt, und auf der anderen Seite existieren betriebliche Zwänge, wie die gemeinsame Koordinierung von Baumaßnahmen mit anderen Leitungsträgern und/oder dem Straßenbau, die zu einer vorzeitigen Auswechslung von Rohrleitungen führen können. Für die Festlegung einer nachhaltigen und zufriedenstellenden Rehabilitationsplanung sollte der Zustand der Anlagen in Verbindung mit dem Rohrnetzalter genauer betrachtet werden. Für die Zustandsbewertung lassen sich beispielsweise die Wasserverluste und die vorhandenen Schadensraten heranziehen. Des Weiteren spielt die Siedlungsstruktur (z. B. ländlicher Bereich bzw. städtischer Bereich) hinsichtlich der Anlagenbelastungen eine wesentliche Rolle (z. B. Verkehrslasten, Grabungsaktivitäten) für die tatsächlichen Nutzungsdauern. Außerdem hat die Siedlungsstruktur entsprechende Auswirkungen auf die Rehabilitationskosten der Rohrleitungen. Im Beitrag wird dargestellt, wie bei der Rehabilitationsplanung die Zustandsbewertung der Anlagen einfließen kann. Welche Einflussfaktoren dabei zu beachten sind, wird anhand von aktuellen Erkenntnissen aus dem ÖVGW-Benchmarking hinsichtlich Netzalter, Wasserverluste und Schadensraten gezeigt. Anhand eines Beispiels der endgültigen Prioritätenreihung für die Erneuerungsplanung wird klar, dass auch die jeweilige Wichtigkeit eines Systemteils hinsichtlich der Versorgungssicherheit für die Planung eine Rolle spielt.Though planning/defining a long-term rehabilitation strategy for drinking-water supply facilities is a frequently discussed topic, it also represents a daunting challenge. Various factors have to be taken into account, e.g. the longevity of drinking-water distribution network which is determined by e.g. the choice of material, pipe diameter and underground conditions on the one hand; and by operational constraints e.g. the need to coordinate planned measures with other service providers and/or the road works, which can result in pipe sections being replaced sooner than planned on the other. In order to achieve sensible and sustainable rehabilitation planning, the current status of the facilities and distribution network must be carefully assessed. In this regard, aspects such as water loss and failure rates could be used as a basis for status appraisals. Furthermore, the municipal structure (e.g. urban or rural) significantly impacts the strain on facilities (e.g. through excavations, increased traffic, etc.), and accordingly, on their actual service lifespans. The specific distribution network structure also significantly impacts the cost of rehabilitation. The paper shows how the assessment of infrastructure current status can be used for better rehabilitation planning. On the basis of the latest insights gleaned from the ÖVGW benchmarking regarding network age, water loss and failure rates, it shows which influencing factors should be kept in mind. Finally, the example of a prioritization plan for rehabilitation strategy clearly demonstrates that the importance of a specific system component is also relevant for session making.(VLID)214133

International Society of Sports Nutrition Position Stand: protein and exercise

Abstract Position statement The International Society of Sports Nutrition (ISSN) provides an objective and critical review related to the intake of protein for healthy, exercising individuals. Based on the current available literature, the position of the Society is as follows: 1) An acute exercise stimulus, particularly resistance exercise, and protein ingestion both stimulate muscle protein synthesis (MPS) and are synergistic when protein consumption occurs before or after resistance exercise. 2) For building muscle mass and for maintaining muscle mass through a positive muscle protein balance, an overall daily protein intake in the range of 1.4–2.0 g protein/kg body weight/day (g/kg/d) is sufficient for most exercising individuals, a value that falls in line within the Acceptable Macronutrient Distribution Range published by the Institute of Medicine for protein. 3) There is novel evidence that suggests higher protein intakes (>3.0 g/kg/d) may have positive effects on body composition in resistance-trained individuals (i.e., promote loss of fat mass). 4) Recommendations regarding the optimal protein intake per serving for athletes to maximize MPS are mixed and are dependent upon age and recent resistance exercise stimuli. General recommendations are 0.25 g of a high-quality protein per kg of body weight, or an absolute dose of 20–40 g. 5) Acute protein doses should strive to contain 700–3000 mg of leucine and/or a higher relative leucine content, in addition to a balanced array of the essential amino acids (EAAs). 6) These protein doses should ideally be evenly distributed, every 3–4 h, across the day. 7) The optimal time period during which to ingest protein is likely a matter of individual tolerance, since benefits are derived from pre- or post-workout ingestion; however, the anabolic effect of exercise is long-lasting (at least 24 h), but likely diminishes with increasing time post-exercise. 8) While it is possible for physically active individuals to obtain their daily protein requirements through the consumption of whole foods, supplementation is a practical way of ensuring intake of adequate protein quality and quantity, while minimizing caloric intake, particularly for athletes who typically complete high volumes of training. 9) Rapidly digested proteins that contain high proportions of essential amino acids (EAAs) and adequate leucine, are most effective in stimulating MPS. 10) Different types and quality of protein can affect amino acid bioavailability following protein supplementation. 11) Athletes should consider focusing on whole food sources of protein that contain all of the EAAs (i.e., it is the EAAs that are required to stimulate MPS). 12) Endurance athletes should focus on achieving adequate carbohydrate intake to promote optimal performance; the addition of protein may help to offset muscle damage and promote recovery. 13) Pre-sleep casein protein intake (30–40 g) provides increases in overnight MPS and metabolic rate without influencing lipolysis