Wall area

A procedure involving only the wall area and based on the cylindrical pore model was put forward by Pierce in 1953. Though simple in principle, it entails numerous arithmetical steps the nature of which will be gathered from Table 3.3 this table is an extract from a fuller work sheet based on the Pierce method as slightly recast by Orr and DallaValle, and applied to the desorption branch of the isotherm of a particular porous silica. 

Here >f(>r,) is the total wall area, and T(>r,) the total length, of all pores having radius greater than r. ... 

As in the other methods, the modelless procedure visualizes the progressive emptying of the pore system, initially full up, by the stepwise reduction in relative pressure. At each step the value of additional core wall area which becomes exposed is calculated by means of the equation (see p. 170) ... 

Here d/l is the additional wall area exposed when the uptake diminishes by dn moles through evaporation from the capillary p." is the chemical potential of the capillary condensate and p° that of the bulk liquid adsorptive. The negative sign is necessary because the area A exposed increases as the uptake diminishes. If the adsorptive vapour behaves as a perfect gas,... 

In order to allow for the thinning of the multilayer, it is necessary to assume a pore model so as to be able to apply a correction to Uj, etc., in turn for re-insertion into Equation (3.52). Unfortunately, with the cylindrical model the correction becomes increasingly complicated as desorption proceeds, since the wall area of each group of cores changes progressively as the multilayer thins down. With the slit model, on the other hand, <5/l for a... 

Core wall area from "Pore wall area from BET area... 

Fig. 4. Cross section of a rotary kiln. is the wall area that is in contact with the soHds (see eq. 10) is the wall area that is in contact with the gases is...

In the mass-transfer limited region, conversion is most commonly increased by using more catalyst volume or by increasing cell density, which increases the catalytic wall area per volume of catalyst. When the temperature reaches a point where thermal oxidation begins to play a role, catalyst deactivation may become a concern. 

Pipe Nominal fliamelcr Wall Area Nominal Mfnnenf Section Radius of G.M.D. 

Debris particles that are heavier than water migrate to the outer wall area and slither down into a collection bowl that is periodically blown down. Very little water is lost. Typical performance is 97.8% of solids with specific gravity exceeding 1.2 down to 45 microns. Side stream filtration is more common in cooling tower applications. The scheme uses a small dedicated pump to draw dirty water from the sump, direct it through a filtration device and sent it back to the basin. 

Note. Where figures for both rooflights and windows in walls are given, these really apply as a combined total. If the full wall window allowance is not used the balance can be reallocated to roof light areas and vice versa. For example, a factory with only 10% of wall area as windows could add the other 5% of wall area as an increase to the permitted 20% of roof area that could be roof lights. 

As with all convective systems, warm air heating installations produce large temperature gradients in the spaces they serve. This results in the inefficient use of heat and high heat losses from roofs and upper wall areas. To improve the energy efficiency of warm air systems, pendant-type punkah fans or similar devices may be installed at roof level in the heated space. During the operational hours of the heating system, these fans work either continuously or under the control of a roof-level thermostat and return the stratified warm air down to occupied levels. 

Pressure is defined as force per unit area. You are probably familiar with the English unit pounds per square inch, often abbreviated psL When we say that a gas exerts a pressure of 15 psi, we mean that the pressure on the walls of the gas container is 15 pounds (of force) per square inch of wall area. 

Diffusion coefficient of ethanol in the polymer matrix Area of the compound layer on the mixer wall Area of the surface of the pool material Concentration of ethanol in the compound... 

The instrument room was planned for work benches covering roughly 60% of the wall area. One wall was left free for bookcases. 

Large surface wall area units also included... 

Radiation is an important modality in the treatment of symptomatic metastatic disease. The most common indication for treatment with radiation therapy is painful bone metastases or other localized sites of disease refractory to systemic therapy. Radiation therapy gives significant pain relief to approximately 90% of patients who are treated for painful bone metastases. Radiation is also an important modality in the palliative treatment of metastatic brain lesions and spinal cord lesions, which respond poorly to systemic therapy, as well as eye or orbit lesions and other sites where significant accumulation of tumor cells occurs. Skin and/or lymph node metastases confined to the chest wall area also may be treated with radiation therapy for palliation (e.g., open wounds or painful lesions). 

The total rate of heat release in the room is assumed to come from five sources the gas burner, the vertical wall area behind the burner, a horizontal strip of material corresponding to the vertical height og the ceiling jet at the ceiling-wall intersection, the wall... 

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