Question

Study Example 2.2. and answer the following:

A vertical gel electrophoresis system consist of a PAGE

gel supported on both sides by glass plates, each surrounded by a fluid stream at the same constant

temperature on both sides. Under the

particular conditions defined below, calculate the maximum

temperature within the PAGE gel.

•PAGE gel dimension (L x W x T) = 10 cm x 10 cm x 0.4cm

•Thickness of each glass plate = 0.5 cm

•Thermal conductivity of the glass plates = 0.8 W/m·K

•Thermal conductivity of the PAGE gel = 0.55 W / m·K

•The temperate of fluid stream at the interface with the glass plate is maintained at 20oC.

•Electrophoresis running condition: 200V, 40 mA

Answer 1

- From Example 2:2, we on the following. > fluid glass 4 Ico2 XT Cosm . “os com the is the shown above get-glass nystem with distribution temperature of page gl - dimension given : oum * 0.4 cm (Om LXWXM each glass plate = 0.50m Thickness of glass plate Thermal conductuctivity of ko2 = 0.8 W/m.k gel kl 0.55 W/m.k Thermal conductivity of

Temperature of thuid ntream at the interface with glans plate T = 20°c. = 293k current & voltage of system: Is 40mA v= 2000, in page gel Cio) temperature Find maximum have Am) from eacample 2.2, we To- T,= Sx, 2 2 kor so heat 1 time generation due to per unit gel. per unit volume eluchie current in and and To-T₂ = 9, (*2*1) ② ko q,= Sx,

S= e resistance to volume of I²R where - Volume of gel (5) - gel. v=IR cohm's law) (v: voltage) 200 V - 5000 m i, :: R* R 40 XIDA i si (HOX163)*x 5000 10x10x10x10x0.410' so 200 kW m 3 (:x,05 si 9,- sx, .200 kw. * (um from figure) -2 10x10 m • 200 kw a voz de on : 200kW q.. 10 kw now find T, using eqn ②

from ean ③ T: Tz + q. (x₂-x.) k oz. 7. T. 293 K + 2956 • home 10 2.5 XID 0.8 W m.k T.: 293k + 62.5k K . : 355.5 determine to Now use equo to from egno To > T, + 5x, ako. Dos 355.5K+ 200 kw x (5x10mm)* m3 2 x 0.55 y m TO 810,045 K