Abstract: This application discloses a method and an apparatus for the measurement of gases in hydraulic fracking sites, comprising a gas sensor, a computer, and a correction factor wherein the correction factor is applied to the observed gas reading to generate a more accurate reading of the gas level at the site.

Abstract: A tunable liquid crystal optical device defining an optical aperture and having a layered structure. The device includes a film electrode formed on a surface of a first substrate and covered by a second substrate, and a contact structure filling a volume within the layered structure and contacting the film electrode. The contact structure is located outside of the optical aperture and provides an electrical connection surface much larger than a thickness of the film electrode, such that reliable electrical connections may be made to the electrode, particularly in the context of wafer scale manufacturing of such a device.

Abstract: This application discloses a method and an apparatus for the measurement of gases in hydraulic fracking sites, comprising a gas sensor, a computer, and a correction factor wherein the correction factor is applied to the observed gas reading to generate a more accurate reading of the gas level at the site.

Abstract: A tunable liquid crystal optical device defining an optical aperture and having a layered structure. The device includes a film electrode formed on a surface of a first substrate and covered by a second substrate, and a contact structure filling a volume within the layered structure and contacting the film electrode. The contact structure is located outside of the optical aperture and provides an electrical connection surface much larger than a thickness of the film electrode, such that reliable electrical connections may be made to the electrode, particularly in the context of wafer scale manufacturing of such a device.

Abstract: A tunable liquid crystal optical device defining an optical aperture and having a layered structure. The device includes a film electrode formed on a surface of a first substrate and covered by a second substrate, and a contact structure filling a volume within the layered structure and contacting the film electrode. The contact structure is located outside of the optical aperture and provides an electrical connection surface much larger than a thickness of the film electrode, such that reliable electrical connections may be made to the electrode, particularly in the context of wafer scale manufacturing of such a device.

Abstract: A tunable liquid crystal optical device defining an optical aperture and having a layered structure. The device includes a film electrode formed on a surface of a first substrate and covered by a second substrate, and a contact structure filling a volume within the layered structure and contacting the film electrode. The contact structure is located outside of the optical aperture and provides an electrical connection surface much larger than a thickness of the film electrode, such that reliable electrical connections may be made to the electrode, particularly in the context of wafer scale manufacturing of such a device.

Abstract: The invention relates to an essentially pressure-insensitive liquid crystal cell. Electrode-equipped (5, 6) plates (1, 2) are arranged at a predetermined distance from each other and define a liquid crystal layer of a thickness d. At least a first (1) of the plates is transparent and has a thickness b not exceeding 1 mm, and a modulus of elasticity E. Spacers (11) fixed in the cavity and having a height h are distributed with a spacing L and have substantially the same modulus of elasticity E as said first plate. The spacers (11) have a width not exceeding 50 &mgr;m, at least in one direction. The degree of the surface coverage s by the supporting areas of the spacers (11) on said first plate (1) exceeds or is equal to a minimum value which is dependent on the type of liquid crystal.

Abstract: Liquid crystal 4-n-pentylphenyl esters of 4'-(trans-4"-n-alkylcyclohex-2-enoyloxy(benzoic acids of the general formula: ##STR1## wherein R is C.sub.2 H.sub.5, n--C.sub.3 H.sub.7.

Abstract: Liquid crystal 4-(4'-cyanodiphenyl) esters of trans-4"-n-alkylcyclohex-2-enecarboxylic acids of the general formula: ##STR1## wherein R is a CH.sub.3 --C.sub.7 H.sub.15 radical of a normal structure. These compounds have low temperatures of the formation of the liquid crystal phase (42.degree.-50.degree. C.), a small heat of transition from the crystal phase into the liquid crystal phase (.DELTA.H=2.7-3.2 kCal/mol), a wide range of the existence of the liquid crystal phase (140.degree. C.).

Abstract: A liquid crystal composition for electrooptical devices for presentation of nformation comprising 2 to 4 parts by weight of liquid crystal 4-(4'-cyanodiphenyl) esters of trans-4"-n-alkylcyclohex-2-enecarboxylic acids of the general formula: ##STR1## wherein R is a normal-structure CH.sub.3 -C.sub.7 H.sub.15 radical, and 6 to 8 parts by weight of 4-n-pentyl-4'-cyanodiphenyl. The composition is characterized by a low temperature of the formation of the liquid crystal phase (below -12.degree. C.), a wide temperature range of the existence of this phase (90.degree.-100.degree. C.), a small threshold voltage (1.1-1.2 V), a short time of switching-on and -off (45 and 65 msec respectively).