Long-term durability

If it has not already been done during the product s development stage, it is essential that during initial commercialization, executive management and QA jointly examine the firm s overall commitment to compliance and total quality performance. In an FDA-regulated environment, an early commitment to forward quality will set the stage for durable, long-term compliance. 

Some researchers reported the effect of the CNT/CHT matrix on an amperometric laccase biosensor, evidencing some of its major advantages, including detection of different substrates, high affinity and sensitivity, durable long-term stability, and facile preparation procedures. 

The development of nonwovens is often associated with the advancement in the hygiene and disposables market. All of these sectors are technically demanding but have tended to mask the equally rapid rise for nonwovens into more durable long-term applications. While we draw the distinction that these are technical applications, we should make it clear that nonwovens used for many of the other disposable applications are no less important or technically complex. 

In cold climates, where this form of damage is a problem, the use of air-entrained concrete is specified. Such concrete has demonstrated its ability to provide durable long-term service. Essentially, additives create air voids entrained in the concrete. The freezing pore solution can then expand into this interconnected system of air voids. Usually the air content of this type of concrete is between 3 and 8 volume percent. However, the total air content alone is not necessarily adequate to assure resistance to freeze-thaw damage. The distribution and size of the entrained air voids are also of major importance. A tradeoff exists between air content and strength. 

Vitis riparia. During the initial testing of GRNl-5, their resistance was tested against multiple individual types of nematodes as well as mixtures of nanatodes (Ferris et al., 2012). These rootstocks should prove to have durable long-term resistance in the future because nematode pressure continues to increase in California vineyards. 

The demands on the PSA performance for these types of applications can be very high, especially in the areas of creep, shear resistance and long-term durability. For these reasons, crosslinked acrylics and stabilized block copolymer adhesives have become the main PSA material choices. 

The reasons for the long-term, commercial robustness of phenolic technology include low cost, versatility, heat and flame resistance, durability, strength and stiffness, low toxicity, and ease of processing. Some key factors are discussed in detail below. 

In-service issues. As mentioned previously, many early service failures of bonded structure were due to adherend surface treatments that were unstable in long-term exposure to water. A majority of these problems were resolved by the adoption of surface treatments such as chromic and phosphoric acid anodize for aluminum details. The remaining few were alleviated by the adoption of phosphoric acid anodized honeycomb core and foaming adhesives resistant to water passage. Other service durability issues such as the cracking of brittle potting compound used to seal honeycomb sandwich assemblies, and subsequent delamination, have been minor in scope. 

Sprayed coatings can be used as a base for painting and it is recommended that a minimum of 0-075 mm of aluminium be used. In practice a combination of 0-1-0-2 mm of aluminium plus paint coatings will give maximum economic durability on long-term structures. 

Researchers are facing difficulties in improving the properties and response rates of chemomechanical andelectrochemomechanical systems based on polymer gels or proteins that are intended to be used as actuators in robotics. Lack of mechanical toughness and long-term durability are other problems to be solved. A basic improvement in the low efficiency... 

Hron P. Hydrophilisation of silicone rubber for medical applications. Polym Int, 2003, 52, 1531-1539. Tcholakian RK and Raad. Durability of anti-infective effect of long term silicone sheath catheters impregnated with antimicrobial agents. Antimicrob Agents Chemother, 2001, 45(7), 1990-1993. 

Effects of Time, Temperature, and Fluids on the Long-Term Service Durability of Elastomers and Elastomeric Components... 

With such a broad subject area, to meet the objectives of the present publication, the general approach for this chapter has been to cover as wide a range as feasible with, where possible, emphasis made on relationships of specific effects with actual service applications. The chapter illustrates various effects of time, temperature, and fluids on long-term service durability of a range of elastomers, mainly by employing various data obtained by Materials Engineering Research Laboratories (MERE) personnel over recent years. 

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