Drop weight

As in the construction industry, piling of the conductor is done by dropping weights onto the pipe or using a hydraulic hammer until no further penetration occurs. In an offshore environment the conductor is either piled (e.g. on a platform) or a large diameter hole is actually drilled, into which the conductor is lowered and cemented. Once the drill bit has drilled below the conductor the well is said to have been spudded. 

Refs. 34 and 35 for a more up-to-date discussion.) This they verified experimentally by determining drop weights for water and for benzene, using tips of various radii. Knowing the values of 7 from capillary rise measurements, and thence the respective values of a, / could be determined in each case. The resulting variation of / with r/V / has been fitted to a smoothing function to allow tabulation at close intervals [36]. 

It is to be noted that not only is the correction quite large, but for a given tip radius it depends on the nature of the liquid. It is thus incorrect to assume that the drop weights for two liquids are in the ratio of the respective surface tensions when the same size tip is used. Finally, correction factors for r/V < 0.3 have been determined, using mercury drops [37],... 

An empirically determined relationship between drop weight and drop time does allow surface tensions to be determined for small surface ages [41],... 

Harkins and Jordan [43] found, however, that Eq. 11-26 was generally in serious error and worked out an empirical correction factor in much the same way as was done for the drop weight method. Here, however, there is one additional variable so that the correction factor/ now depends on two dimensionless ratios. Thus... 

The surface tension of a liquid is determined by the drop weight method. Using a tip whose outside diameter is 5 x 10 m and whose inside diameter is 2.5 x 10 m, it is found that the weight of 20 drops is 7 x 10 kg. The density of the liquid is 982.4 kg/m, and it wets the tip. Using r/V /, determine the appropriate correction factor and calculate the surface tension of this liquid. 

The following values for the surface tension of a 10 Af solution of sodium oleate at 25°C are reported by various authors (a) by the capillary rise method, y - 43 mN/m (b) by the drop weight method, 7 = 50 mN/m and (c) by the sessile drop method, 7 = 40 mN/m. Explain how these discrepancies might arise. Which value should be the most reliable and why ... 

Reactivity (instability) information Acceleration rate calorimetry Differential thermal analysis (DTA) Impact test Thermal stability Lead block test Explosion propagation with detonation Drop weight test Thermal decomposition test Influence test Self-acceleration temperature Card gap test (under confinement) JANAE Critical diameter Pyrophoricity... 

Gas does not have the lubricant qualities of fuel oil. Consequently, whereas a drop-weight valve in the oil supply can be expected to close when called upon, this is not the case with a relatively large-bore gas ball valve or plug valve used for gas. 

Acetone cyanohydrin nitrate should be regarded as a moderately explosive material and should be handled carefully and distilled behind a safety shield. For purposes of comparison, the drop-weight sensitivities on the Olin-Mathieson drop-weight tester of three materials are propyl nitrate, 10 kg.-cm. acetone cyanohydrin nitrate, 40 kg.-cm. nitromethane, 60 kg.-cm. 

Drop weight test Thermal decomposition test Influence test... 

Surface tension of the nonpolarized ITIES was investigated by using the drop-weight [2,3,29], maximum bubble pressure [30] and pendant drop [4] methods. The latter method... 

The same system has been studied previously by Boguslavsky et al. [29], who also used the drop weight method. While qualitatively the same behavior was observed over the broad concentration range up to the solubility limit, the data were fitted to a Frumkin isotherm, i.e., the ions were supposed to be specifically adsorbed as the interfacial ion pair [29]. The equation of the Frumkin-type isotherm was derived by Krylov et al. [31], on assuming that the electrolyte concentration in each phase is high, so that the potential difference across the diffuse double layer can be neglected. 

This nitroguanidine analogue is more sensitive than RDX by the drop-weight... 

Very shock sensitive explodes in drop-weight test at 11 kg-cm. 

The determination of the mechanical shock sensitivity or impact sensitivity is applicable to both solids and liquids. The principle involved is that a drop weight falls from a specified height onto the confined test sample. The load can be varied by changing the height of the drop and by changing the drop weight. 

Drop weight test A weight is dropped on a sample in a metal cup. The test measures the susceptibility of a chemical to decompose explosively when subjected to impact. This test should be applied to any materials known or suspected to contain unstable atomic groupings. 

A relatively unstable material, the energetic decomposition of which can be initiated by merely the input of mechanical energy at normal ambient conditions. Materials are considered as shock sensitive if they are more easily initiated than dinitrobenzene in a standard drop-weight test. 

The product from the distillation was analyzed by drop weight testing and differential scanning calorimetry (DSC). The drop weight test indicated that the product was not shock sensitive. By DSC, there was a 400 cal/g release of energy which initiated at 135°C. The pot residue showed a slow release of energy which was estimated to be ca. 100 cal/g and initiated at 150°C. 

In an investigation by the U.S. Bureau of Mines1141, in which a drop weight type of crusher was used, it was found that the increase in surface was directly proportional to the input of energy and that the rate of application of the load was an important factor. 

The apparent efficiency of the size reduction operation depends on the type of equipment used. Thus, for instance, a ball mill is rather less efficient than a drop weight type of crusher because of the ineffective collisions that take place in the ball mill. 

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