Mandatory recovery systems

Fuel cell recovery is now and can in the future be voluntary or mandatory. Voluntary systems, sometimes called extended product responsibility , can mean the reuse and remanufacturing of components back into a company s products as an integral part of the company s business model. It can also mean the development of a close business relationship with material recyclers. Experiences in the automotive industry provide some insights into voluntary systems. Whereas the... 

Such approaches underpin the current popularity of RP-HPLC procedures for the purification of synthetic or recombinant polypeptides at the production scale, or analogous approaches employed in the HP-IEX of commercially valuable proteins. However, in some cases when linear scale-up methods are applied to higher molecular weight polypeptides or proteins, their biological activity may be lost due to unfavorable column residency effects and sorbent surface area dependencies. It is thus mandatory that the design and selection of preparative separation system specifically address the issues of recovery of bioactivity. Often some key parameters can be easily controlled, i.e., by operating the preparative separation at lower temperatures such a 4°C, or by minimizing column residency times. 

Determinations of the adsorption isotherms for a number of organic solvent-water systems in contact with hydrocarbonaceous stationary phases have shown that a layer of solvent molecules forms on the bonded-phase surface and that the extent of the layer increases with the concentration of the solvent in the mobile phase. For example, methanol shows a Langmuir-type isotherm when distributed between water and Partisil ODS (56). This effect can be exploited to enhance the resolution and the recoveries of hydrophobic peptides by the use of low concentrations, i.e., <5% v/v, of medium-chain alkyl alcohols such as tm-butanol or tert-pentanol or other polar, but nonionic solvents added to aquo-methanol or acetonitrile eluents. It also highlights the cautionary requirement that adequate equilibration of a reversed-phase system is mandatory if reproducible chromatography is to be obtained with surface-active components in the mobile phase. 

Inherent in all RPC and HlC investigations with peptides or proteins is the question of the end use to which the separated products will be applied. If the task involves purification solely for subsequent primary structure determination (i.e., essentially an analytical task at a semi-preparative scale), then control over preservation of bioactivity may not be necessarily relevant. Obviously, with a new or partially characterized protein, recovery of the component of interest with high mass and bioactivity balance is essential. For preparative methods where subsequent biological uses are contemplated, it is similarly mandatory that the design of the RPC or HlC separation system specifically address recovery issues. High recovery of bioactivity can usually be satisfied without sacrificing the obvious demands of selectivity through proper attention to the physicochemical consequences of the dynamic behavior of the polypeptide or protein of interest in bulk solution and at liquid-solid interfaces. 

Model-based development of software has become more and more common over the years. Software can be designed and verified using behavioral models developed in e.g. Simulink [1], which is one of the most popular tools for this purpose. For safety-related software developed in Simulink, compliance with recommendations from functional safety standards may be required. For example, if the international standards lEC 61508 [2] or ISO 26262 [3] are used, they require that systems shall be able to handle faults, and fault injection is either recommended or mandatory according to these standards. Fault injection is an experimental method to exercise and evaluate error detection and recovery mechanisms, and it can also be used in an iterative manner to improve software robustness. 

Germany Packaging 64% plastic recycling Mandatory deposit/ refund system. DSD system responsible for collection and recovery of packaging. 

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