While Stacking Loads

Never permit anyone to stand or walk under the load-engaging mechanism of the walkie trucks. Keep the arms, hands, feet, legs, and head away from the upright mast at all times. 

Stack product securely on the forks. Restack an unbalanced load before moving it. Loads that are not secured should be equipped with metal or plastic banding or plastic shrink wrapping. 

Never overload the walkie. The manufacturer s data plate identifies the capacity. Capacity can easily be made more visible to all operators by stenciling the numbers on the sides of the powered equipment. 

Keep loads stacked as low as possible. Overloaded pallets can easily strike the top of a trailer while entering. Dislodged product can easily fall back onto the operator or someone else. 

Allow for proper turning and positioning clearances when moving loads. The stacked product can easily strike other product, racking, electrical equipment, sprinkler pipe, or parts of the building structure. 

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Note that block stacking has another advantage flexihUity. Since there is no permanent rack structure, when stacked loads are retrieved (or if the need for storage space decreases over time), the floor space that opens up may be used for other purposes, provided new loads are not stored in the system shortly thereafter. To protect and support the loads at the bottom while avoiding the cost and loss of flexibility associated with a permanent rack, some systems use portable racks, also known as stacking frames, (Figure 17), which are basically self-contained steel units made up of four posts attached to a deck. (An alternative design is a frame that is attached to the pallet itself.)... 

Electrical management, or power conditioning, of fuel cell output is often essential because the fuel cell voltage is always dc and may not be at a suitable level. For stationai y applications, an inverter is needed for conversion to ac, while in cases where dc voltage is acceptable, a dc-dc converter maybe needed to adjust to the load voltage. In electric vehicles, for example, a combination of dc-dc conversion followed by inversion may be necessary to interface the fuel cell stack to a, 100 V ac motor. 

As with the electrical load profile, it is also necessary to analyze the heat load over the daily and annual cycles. Ideally, the heat load will match the available heat from the electrical generator (however, this is rarely the case). There will be periods when supplementary output will be necessary which can be achieved by, say, supplementary firing the waste heat gases of a gas turbine, or heat output reduction is necessary by the introduction of bypass stacks. For a steam turbine installation bypass pressure-reducing valves will be necessary to supplement steam output, while a dump condenser may be needed at low-process steam demands. The nature of the electrical and heat load will obviously have significant influence in the development of the scheme and scope of equipment. 

There are two questions that needed to be answered here. (1) How can the ligand access the interiors of big prismatic particles to lead to the smaller particles and (2) Why do the ligands lead to smaller particles at all While it is difficult to conclusively find answers to both the questions, the first step in the digestive ripening procedure offers some leads. (1) The big prismatic particles obtained by the reverse micelle-based synthesis are loaded with defects such as twinning boundaries and stacking faults. 

Furnace temperatures have also been shown to be important in controlling the formation of COS. While COS has little effect on the downstream Claus catalyst efficiency its presence in the gas stream leads to higher loading of the reductive tail gas clean-up processes (e.g. SCOT, BSR, see environment) or to higher SO2 emissions in the stack gas. The recent developments regarding the control of its formation in the front end furnace are thus a significant contribution to the improvement of environmental quality control. 

Endurance is a critical issue in the commercialisation of MCFCs. Adequate cell performance must maintain an average potential degradation no greater than 15 mV/a over a cell stack lifetime of 5 years, while state-of-the-art MCFCs exhibit an average degradation of 40 mV/a. At full load, MCFC system can achieve efficiencies up to 55%, which drops at partial loads. Typical MCFCs operate in the range 100-200 mA/cm2, at 750-900 mV/cell, achieving power densities even above 150 mW/cm2 (US DOE, 2002 Larminie et al., 2003 Yuh et al., 2002). 

The stack output voltage ranges from 34 V at open circuit to 22 V at full load, while the electric motor is supplied at 48 V DC. For this reason, a DC-DC converter (see Sect. 5.2) is used to match the stack output voltage with that required by the engine. In Table 6.3, the technical specifications of the DC-DC converter are shown. 

The experimental evaluation of other effects associated with the operative temperatures and stoichiometric ratio is performed in a range of pressure around 130 kPa, using the side channel air compressor whose characteristics are described in Table 7.1. The effect of the stack temperature on the voltage measured at the stack terminals is shown in Fig. 7.8. In this case, the temperamre is controlled by varying the water flow rate in the heat exchanger shell while the air flow rate and humidification conditions are the same as those of Fig. 7.7. It can be observed that a decrease in temperamre from 346 to 305 K determines a voltage reduction <10% up to 70% of load (200 A), while a satisfactory stack behavior at 313 K is detected in almost all load conditions (see Sect. 3.3). Then, the effect of the stoichiometric ratio is verified for three different loads at the stack and humidification temperature of 313 K. From Fig. 7.9, it can be noted that values of R higher than 2 are... 

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