Supplementary bonding

In both cases, amino acids that can modulate chemical-physical properties such as lipo-philicity (like 11, present in saquinavir and nelfmavir), can produce supplementary bonds (like 12 and 13 [42]), or can induce stereochemical constraint (like 14 [43]) are frequently used (Fig. 15). The design and synthesis of conformationally constrained amino acids as scaffolds for peptidomimetics synthesis, has been recently reviewed by Hanessian [44]. 

A permanent label must also be fixed in a visible position at or near the point of connection of the bonding conductor with the words Safety Electrical Connection - Do Not Remove (lET Regulation 514.13.1). Supplementary bonding is described later in this book. 

Test for continuity of protective conductors, including protective bonding and supplementary bonding. 

The object of the test is to ensure that the CPC is correctly connected, is electrically sound and has a total resistance which is low enough to permit the overcurrent protective device to operate within the disconnection time requirements of Regulation 411.4.6, should an earth fault occur. Every protective conductor must be separately tested from the consumer s main protective earthing terminal to verify that it is electrically soimd and correctly connected, including the protective equipotential bonding conductors and supplementary bonding conductors. 

Where other potential metallic conductors exist near to electrical conductors in a building, they must be connected to the main earth terminal to ensure equipo-tential bonding of all conductors to earth. This applies to gas, water and central heating pipes and other devices such as lightning protection systems. Supplementary bonding is required in bathrooms and kitchens where, for example, metal sinks and other metallic equipment surfaces are present. This involves the connection of a conductor from the sink to a water supply pipe which has been earthed by equipotential bonding. There have been several fatalities due to electric shocks from live service pipes or kitchen sinks. 

Section 547 covers main and supplementary bonding conductors. Their purpose is to maintain touchable metalwork in the equipotential zone at the same potential so as to avoid the possibility of electric shock to anyone touching different metalwork items at the same time. It is necessary to check that joints in metal pipes are metal-to-metal to ensure low resistance otherwise bonding across is needed. Look out for plumbing in which both... 

Supplementary bonding must be provided in bathrooms even if there are satisfactory metal-to-metal joints because of the enhanced shock risk see section 601. Consideration should be given to the provision of supplementary equipotential bonding in kitchens, sculleries and laundry rooms with conducting floors, such as quarry tiles, particularly if they are likely to be wet, again because of the enhanced shock risk. Similar locations in commercial and industrial premises should receive the same consideration. 

Regulation 551-04-04 addresses protection against indirect contact for static inverters, typically used for uninterruptable power supplies in installations where continuity of supply is crucial. Where the disconnection times of section 413-02 cannot be achieved, supplementary bonding must be used to minimise the risk of a shock between exposed metalwork. A warning is provided in Regulation 551-04-05 about the possible deleterious effects on the operation of protective devices, such as circuit breakers, of direct current generated by the static inverter or filters. 

Protection against overcurrent and electric shock is in section 3. It compares the performances of semi-enclosed and cartridge fuses and MCBs for both overcurrent and short circuit protection. It deals with RCDs for earth leakage and electric shock protection. It concludes with Tables 10 and 11 for the sizes of main earthing, main bonding and supplementary bonding conductors. 

Test the continuity of the protective conductors including the main protective bonding conductors and supplementary bonding conductors. 

The wormlike chain of Kratky and Porod (the KP chain) is a continuous limit of a freely rotating chain derived by letting N (the number of bonds) —> bond length) —> 0, and 0f (the supplementary bond angle) —> 0 under the conditions that... 

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