Oscillating steel ball

Another experimental setup that has been used in the literature by Hensel et al. [55] to evaluate the mechanical durability of their omniphobic polymer membranes is the oscillating steel ball. A steel ball with a diameter of 

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Figure 9.9 Wear tests on (a) polymer membranes in comparison to (b) pillar arrays Schematic representation of the experimental setup consisting of an oscillating steel ball, pressed onto the structured surfaces. Experimental data on maximum normal loads the surfaces can resist without destruction and SEM images after failure [55],...

Carbon monoxide is admitted slowly and the pressure boosted to ca. 1600 p.s.i. The vessel is allowed to stand connected to the gas line for 10 minutes, and the valve is then closed. The shaking mechanism is adjusted for widest possible oscillation to allow the steel ball to roll back and forth to shatter the ampoule and mix the reactants. The vessel is heated to 100° and maintained at this temperature for 4 to 6 hours, f The vessel is allowed to cool, and then with the valve at the top the contained gas is bled off through the vent line. The pressure vessel is opened in a hood, and its contents are transferred into a 1-1. distilling flask containing ca. 500 ml. of water. The ether is distilled off at low temperature. When the ether has been removed, the receiver is changed and the water in the flask boiled. The tungsten hexacarbonyl is carried over into the receiver with the steam, j Water is removed on a Buchner funnel, and the product is purified by redistillation from 3 to 5% sodium hydroxide solution, by vacuum sublimation at 60 to 70°, or by crystallization from ethyl ether. The yield varies from 6 to 8 g. (68 to 90%), depending upon conditions. ... 

Oscillating ball mill, model MM400 (Retsch, Haan, Germany) with steel balls (5-mm diameter)... 

The amount of material may range between 25 and 100 mg for a single sample however, it should be noted that (1) a bigger sample is easier to deal with and (2) the volume of solvent used for extraction has to be adjusted accordingly. Homogenization of the plant material should be performed after the addition of steel balls (two per Eppendorf tube) in the oscillating mill (e.g., in Retsch mill MM series). 

Each ground mixture of LOR and P-CD (LOR/P-CD) or LOR and HP-P-CD (LOR/HP-P-CD) with a 1 1 molar ratio was respectively prepared in an oscillatory ball mill (Mixer Mill MM301, Retsch GmbH Co., Germany) with 15 Hz oscillation frequency. About 0.2 g of powder sample was placed in a 25 ml volume stainless steel milling jar containing two 15 mm diameter stainless steel balls, and then oscillated. In the grinding process, the sample was withdrawn at the prescribed intervals for further examination (Lin et al, 2010). 

Flutter breathing is a combination of PEP and air column oscillation applied at the mouth. It is an inexpensive means of oscillating the air column in conjunction with providing PEP. The patient expires through a small pipe shaped device called Flutter VRPI . The expiratory opening of the pipe is closed by a small stainless steel ball. 

In the Persoz hardness test [61], the hardness of a coating is measured by determining the damping time of an oscillating pendulum. The pendulum rests with two stainless steel balls on the coating surface. When the pendulum is set into motion,... 

Stainless steel (100CR6-German) + Stainless steel (100CR6 -German) 0.6 (a) 0.26 (b) 0.106 (c) 0.1 (d) Ball-on-disk vibrotribometer (Optimol SRV - German) 10 mm diameter ball Oscillation = 10 Hz 1.65 mm amplitude Load = 50 300 N Lub (a) none (b) human synovial fluid (c) yellow bone marrow (d) red bone marrow 37 °C Gavrjushenko (1993)... 

The sliding wear behaviour of the untreated and treated samples was assessed using oscillating ball-on-disk type tribometer. The depth of the wear tracks of examined samples as a fxmction of wear path at a load of 3 N is shown in Fig. 5. Generally, the wear resistance of the untreated samples in comparison to the treated is extremely poor. For all treated samples, examined up to 320 m wear path, maximum one micrometer wear depth has been observed and the wear depth slowly increases with increasing wear path. Otherwise the wear rates have been accounted as total volume loss in irurf divided by the total sliding distance in meters. The wear rates for the untreated material were accounted in order to know the improvement in the wear rates for treated one. The wear rate for the xmtreated 304 austenitic stainless steel was 2.4 x 10-4 mmV m at 20000 numbers of tracks (80 m wear path). 

Instead of an oscillating ball as described in the previous section, an alternative abradant material could be an oscillating ring. Groten and Ruhe [56] used an experimental setup comprising a steel ring (diameter 2 cm,... 

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