Protective bonding

By considering these features, the enormous difficulties associated with overcoming the enzymatic barrier to peptide and protein delivery should be apparent. Degradation usually occurs at the site of administration and is possible in every anatomical site en route to the target receptor. Furthermore, protecting a single bond on a peptide or protein drag from a particular type of enzyme is insufficient to confer protection on the entire dmg from enzymatic hydrolysis—other enzymes may attack the protected bond and the other unprotected bonds on the dmg are still vulnerable. 

Atom-transfer and group-transfer polymerizations are variants of these processes, in which radical or anionic chain ends - instead of occurring freely as such - are temporarily released by breaking a suitably labile, but otherwise protective bond (e.g. to a Cu atom or to a McsSi group) which then gets reattached to the newly-formed chain end. 

Fault protection is protection against electric shock under single fault conditions and is provided by protective bonding and automatic disconnection of the supply (by a fuse or MCB) in aooordance with lET Regulations 411.3 to 6,... 

Protection from electric shock is provided by basic protection and fault protection. Protective bonding is bonding for the purpose of safety. 

Figure 3.6 Main protective bonding of gas and water supplies.

Protective bonding coupled with automatic disconnection of the supply. 

The method which is most universaiiy used in the United Kingdom is, therefore, Method 1 - protective bonding coupied with automatic disconnection of the suppiy. 

Supplementary protective bonding to pipework will only be required as an addition to fault protection (lET Regulation 415.2) if the immersion heater vessel is in a bathroom that does not have ... 

PVC cables enclosed in heavy-duty PVC conduit are suitable for installations in most agricultural buildings. All exposed and extraneous metalwork must be provided with supplementary protective bonding in areas where livestock is kept (lET Regulation 705.415.2.1). In many situations, waterproof socket outlets to BS 196 must be installed. All socket outlet circuits must be protected by an RCD complying with the appropriate British Standard and the operating current must not exceed 30 mA. 

II) the bath or shower is located in a building with main protective bonding in place, as described in Fig. 3.6 (lET Regulation 411.3.1.2). 

Note Local supplementary protective bonding may be an additional requirement of the Local Authority regulations in, for example, licensed premises, student accommodation and rented property. 

The lET Regulations describe the need to consider additional protection by supplementary protective bonding in situations where there is a high risk of electric shock (e.g. in kitchens and bathrooms) (lET Regulation 415.2). 

In rooms containing a fixed bath or shower, supplementary protective bonding conductors must be installed to reduce to a minimum the risk of an electric shock unless the following two conditions are met ... 

The bathroom is located in a building with a main protective bonding system in place (lET Regulation 701.415.2). Such a system is shown in Fig. 3.6. 

Supplementary protective bonding conductors in domestic premises will normally be of 4mm copper with PVC insulation to comply with lET Regulation 543.1.1 and must be connected between all exposed metalwork (e.g. between metal baths, bath and sink taps, shower fittings, metal waste pipes and radiators), as shown in Fig. 3.79. 

Figure 3.79 Supplementary protective bonding in bathrooms to metal pipework.

The protection provided by main protective bonding and automatic disconnection of the supply is called ... 

---