Paddle cell

Daucus carota Petunia mitchelle Glycine soja Haake rotoviscometer (paddle system) turbulent mitochondrial activity cell lysis (cell no.) aggregate size non-growth [57, 69]... 

Fig. 2.1.10 Complete cell with a paddle with one row of holes (blade stirrer), mounted in a glass tube (left), a second paddle with two rows of holes (middle) and a propeller mounted on a rotation axis (right) used to study the velocity distribution in different types of mixers.

The rheo cells can easily be replaced by various types of mixers, propellers or paddles (Figure 2.1.10). It is then possible to analyze the temporal evolution of chemical/physical reactions of mixing, demixing and sedimentation of materials in process engineering, e.g., during the mash process or fermentation [28, 29]. The stirring mechanics and speed can be optimized for various materials of different particle sizes and viscosity. 

Byron and coworkers [7,8] developed and evaluated a transport cell which proved to be useful in predicting interfacial transfer kinetics between aqueous and organic boundary layers. In this system, stirring is generated by using paddles in each phase. These investigators demonstrated that successful prediction of the transfer kinetics of any homologue in a series was possible in all cases from... 

Typically around 3—5% of saponified fatty acids would be added to the flotation cell. The air bubbles attract ink particles and, as the ink-rich air bubbles reach the surface, they are removed by means of a slowly rotating paddle. The froth is withdrawn and further concentrated prior to disposal. 

Basket, paddle, reciprocating cylinder, or flow-through cell Paddle Paddle... 

Basket, paddle, or reciprocating cylinder with glass beads Paddle over disk Franz cell diffusion system Paddle, modified basket, or dual chamber flow-through cell Special apparatus [European Pharmacopoeia (PhEur)] Flow-through cell (powder/granule sample cell)... 

Eigure 4.32 shows a typical thermostated stirred cell. The liquid volumes are commonly 50 -i- 50 mL. The stirrer may consist of a single paddle at the interface, or a double paddle, one in the center of each phase. The cell may contain baffles, etc., to improve the mixing. Stirring may be violent, completely destroying the interface and producing very small ( 1 mm) droplets, or slow... 

The preferred dissolution apparatus is 1 ISP apparatus 1 (basket) or 11 (paddle), used at compendially recognized rotation speeds (e.g., 100 rpm for the basket and 50-75 rpm for the paddle). In other cases, the dissolution properties of some ER formulations may be detennined with USP apparatus 111 (reciprocating cylinder) or IV (flow through cell). 

The skimmed oil Is collected and transferred to wet crude tank. Water from the SPI separator is discharged to induced air floatator. This unit is composed of four floatation cells. Each cell is equipped with a motor driven self-aerating rotor meonanistn. As the rotor spins, minute bubbles are generated ar.d oil and suspended solid particles attach to the gas bubbles as tney rise to the surface. Tne oil and suspended solids gather in a dense froth on the surface and are removed from the cell by skimmer paddles and collected in a scum tank. Then skum is pumped out of scum tank to the inlet of SPI separator by skum return pump. 

Skimmer paddles are provided along both sides of the unit. Gas-tight inspection hatches are located above the skimmer paddles on each cell for inspection and maintenance. 

Until now, bioreactors of various types have been developed. These include loop-fluidized bed [14], spin filter, continuously stirred turbine, hollow fiber, stirred tank, airlift, rotating drum, and photo bioreactors [1]. Bioreactor modifications include the substitution of a marine impeller in place of a flat-bladed turbine, and the use of a single, large, flat paddle or blade, and a newly designed membrane stirrer for bubble-free aeration [13, 15-18]. Kim et al. [19] developed a hybrid reactor with a cell-lift impeller and a sintered stainless steel sparger for Thalictrum rugosum cell cultures, and cell densities of up to 31 g L1 were obtained by perfusion without any problems with mixing or loss of cell viability the specific berberine productivity was comparable to that in shake flasks. Su and Humphrey [20] conducted a perfusion cultivation in a stirred tank bio-... 

Flower [25], Panda et al. [26], Doran [27]. and Payne et al. [28]. Several kinds of bioreactors, such as the stirred tank bioreactor with hollow paddle and flat blade impellers, the bubble column, the airlift bioreactor with internal and external loops, the rotating drum bioreactor, the stirred-tank with a draft tube, and the mist bioreactor have been attempted for plant cell, tissue and organ cultures (Fig. 1). 

The complexity of the cilium and other swimming systems is inherent in the task itself. It does not depend on how large or small the system is, whether it has to move a cell or move a ship in order to paddle, several components are required. The question is, how did the cilium arise ... 

The function of the cilium is to be a motorized paddle. In order to achieve this function microtubules, nexin linkers, and motor proteins all have to be ordered in a precise fashion. They have to recognize each other intimately, and interact exactly. The function is not present if any of the components is missing. Furthermore, many more factors besides those listed are required to make the system useful for a living cell the cilium has to be positioned in the right place, oriented correctly, and turned on or off according to the needs of the cell. 

Using 1 m2 containers provided with a paddle-wheel (Fig. 1) the effect of several factors on biomass yield have been assayed at 30°C in outdoor semicontinuous cultures. At the moderate irradiance proper of autumn and winter (below 10 MJ m-2 day- ), the turbulence furnished by the paddle-wheel (15-20 rpm) suffices to provide all the C and N required for optimal cell growth. Under these conditions and in the presence of 50 mM NaHC03 but without any C02 supply (pH 9.3), productivity of Anabaena ATCC 33047 was 8-13g (dry weight) m-2 day-1. In summer (irradiance, 20-25 MJ m-2 day l), productivities of more than 25g (dry weight) m-2 day-1 were recorded, provided that the cultures were supplemented with C02 at a flow rate of 1 mole m-2 day-1 in addition to bicarbonate. Under these conditions, addition of C02 was an absolute requirement for pH maintenance and growth enhacement, whereas a supply of air-N2 or combined nitrogen did not improve productivity (Moreno et al., 1987). 

---