Gas inclusions

Samples for analysis may be solids, liquids, or gases, or any forms in between and in combination, such as slurries, gels, and gas inclusions in solids. Samples can be clear or opaque, highly viscous or liquids with lots of suspended solids. While this variety is easy for Raman spectroscopy, it would be challenging for mid-IR and near-infrared (NIR) spectroscopy and numerous non-spectroscopic approaches. 

Schurig, V., Grosenick, H., and Green, B. S. (1993) Preparative enantiomer separation of the anesthetic enflurane by gas inclusion chromatography. Angew. Chem. Int. Ed. 32, 1662-1663. 

Clifford 2000). Many metallic ore and evaporite minerals contain methane, though not in hydrate form. For instance, the Red Dog zinc ores mentioned above contain methane inclusions in association with saline inclusions. In many instances, microscopic methane and carbon-dioxide-rich fluid inclusions form clathrates within their tiny hydrous envelopes. Some salt deposits are so enriched in high-pressure free gas inclusions and/or gas hydrates that mining, crushing under boot, or other means of physical disturbance causes popping or even explosive decrepitation. 

Thin, flat discontunities found in steel plate due to gas inclusions or pipe in the original ingot... 

Surface shrinkage cracks at a crater. Cracks in parent metal adjacent to weld. Other discontinuities due to lack of fusion, penetration, overlapping and slag and gas inclusions... 

The critical diameter is the minimum diameter of an explosive charge at which detonation can still take place. It is strongly texture-dependent, and is larger in cast than in pressed charges. Finely dispersed gas inclusions considerably reduce the critical diameter. 

In the above equation, is a model constant, R is the ideal gas constant and H is a pseudo-Henry s constant. These examples illustrate how, once the mechanisms underlying gas incorporation are identified, it is possible to establish a relationship between operating parameters and the level of gas inclusion. 

The history of crystalline gas adsorbents is old and starts with the mineral zeolite. Nowadays, there are successful synthetic techniques for the production of zeolites and zeotypes with controlled diameter pores. Moreover, processes able to produce porosity in pure organic and metal-organic skeletons have been developed. Typical compounds suitable for the topics of this chapter are shown in Fig. 3.4.6. They possess inner accessible spaces for gaseous guests to generate a gas inclusion state... 

Phase Transition of the Adsorbed Guest Sublattice in the Gas Inclusion Co-crystal State [23]... 

Besides bread and cake, in which yeast or baking soda is used to obtain gas cells, other baked products have gas inclusions without C02... 

Purity Better (no gas inclusions, very high vacuum) Possibility of incorporating impurities (low-medium-vacuum range)... 

Traces of methane have actually been detected in the pores of certain samples from HM-i with the aid of mass spectrometry of gas inclusions (Table 7.5). This CH exhibits a rather light carbon isotope composition and could even have participated in the establishment of the of the recrystallized carbonates in the upper parts of HM-i. However, the observed traces of CH are associated with greater concentrations of hydrogen (H ) and nitrogen (N ) which would imply a primary origin of the methane (Table 7.5). 

Blistering due to gas formation or gas inclusion Volahle components leading to bhster formahon can become incorporated in the coating during application, or they can result from inclusions of solvents from phase separation. They can also be generated because of cathodic protection or even to a corrosion process if it generates H2. 

Solid Dispersion (e.g., cermet) Liquid inclusions Gas inclusions (e.g., styrofoam)... 

Foamed materials can be considered to be the opposite of fiber reinforcement (see Cellular materials). In a foam, the gas inclusions make the matrix softer... 

Voids and Gas Inclusions. Voids and gas inclusions are relatively easy to identify in imreinforced polymers. They constitute the only voids in the fracture... 

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