Sustainability defined

Sustainability Define processes that are simple and an integral part of operational requirements to ensure that these processes do not become a heavy burden or an obstacle for improvement. 

Ceramic membranes, which are much stronger than polymer membranes, are conunonly made of Al, Si, Ti or Zr oxides and mixed oxides. The top layers of the membrane are prepared by sol-gel synthesis which converts a colloidal or polymeric solution of inorganic precursors (e.g. alkoxides or salts) to a gelatinous product. Viscous binders are usually added prior to layering followed by controlled calcination and finally sintering to form the ceramic membrane. The process can be controlled to provide membranes with specific MWCOs (molecular weight cut-offs) and which can sustain defined solvents, temperatures and pressures. 

In the case of most nonporous minerals at sufficiently low-shock stresses, two shock fronts form. The first wave is the elastic shock, a finite-amplitude essentially elastic wave as indicated in Fig. 4.11. The amplitude of this shock is often called the Hugoniot elastic limit Phel- This would correspond to state 1 of Fig. 4.10(a). The Hugoniot elastic limit is defined as the maximum stress sustainable by a solid in one-dimensional shock compression without irreversible deformation taking place at the shock front. The particle velocity associated with a Hugoniot elastic limit shock is often measured by observing the free-surface velocity profile as, for example, in Fig. 4.16. In the case of a polycrystalline and/or isotropic material at shock stresses at or below HEL> the lateral compressive stress in a plane perpendicular to the shock front... 

Flanumbility limits (or explosion limits) for a flammable gas define tlie concentration range of a gas-air ini. ture witliin wliich an ignition source can start a self-propagating reaction. Tlie minimmn and maximmn fuel concentrations in air tliat will produce a self-sustaining reaction mider given conditions are called tlie lower Jlammability limit (LFL) and tlie upper Jlammability limit (UFL). (The abbreviations LEL and UEL, for lower and upper explosivity limits, are sometimes used.) The flanunability limits are functions of... 

The fatigue strength is defined as that stress level at which the test specimen will sustain N cycles prior to failure. The data are generated on a machine that runs at 1800 cycles per minute. This test is of value to material manufacturers in determining consistency of their product (Chapter 2). 

In human exercise physiology, fatigue is often defined as an inability of a muscle or a group of muscles to sustain the required or expected force (Edwards, 1981). This definition is very applicable for the study of factors limiting dynamic or isometric exercise in intact organisms at varying intensities. 

Water scarcity is defined as a situation where insufficient water resources are available to satisfy long-term average requirements. It refers to long-term water imbalances, where the availability is low compared to the demand for water, and means that water demand exceeds the water resources exploitable under sustainable conditions. 

Chronic HCV infection is curable, and cure is the goal of antiviral therapy. Successful treatment is characterized by a sustained virological response (SVR), defined by undetectable HCV RNA in a sensitive assay (detection limit < 50 international units (IU)/ml) 6 months after the end of therapy. Recent large-scale follow-up studies have shown no relapse or recurrence after 4-6 year s in more than 99% of patients who have an SVR (McHutchison et al. 2006 Swain et al. 2007). 

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