The present disclosure provides methods for determining surfactant retention values in subterranean reservoirs. In particular, the methods comprise conducting at least one single well chemical tracer test and performing a straight line analysis on a saturation profile of the subterranean reservoir.

The present invention relates to nucleic acids or nucleic acid fragments encoding amino acid sequences for polypeptides involved in tolerance to freezing and/or low temperature stress in plants. More particularly, the present invention relates to nucleic acids or nucleic acid fragments encoding amino acid sequences for ice recrystallization inhibition proteins (IRIPs) in plants, and the use thereof for the modification of plant response to freezing and/or low temperature stress. Even more particularly, the present invention relates to polypeptides involved in tolerance to freezing and/or low temperature stress in Deschampsia and Festuca species.

The invention concerns a method of marking a hydrocarbon liquid comprising the

##STR00001##

step of adding to said liquid, as a tracer compound, a compound of Formula I or Formula II: wherein at least one of R.sup.1-R.sup.6 in Formula I and at least one of R.sup.7-R.sup.14 in Formula II is selected from: i. a bromine or fluorine atom; ii. a partially or fully halogenated alkyl group; iii. a branched or cyclic C.sub.4-C.sub.20 alkyl group; iv. an aliphatic substituent linking two positions selected from R.sup.1-R.sup.6 in Formula I to one another or two positions selected from R.sup.7-R.sup.14 in Formula II to one another; or v. a phenyl group substituted with a halogen atom, an aliphatic group or halogenated aliphatic group
and none of R.sup.1-R.sup.6 in Formula I and none of R.sup.7-R.sup.14 in Formula II being a sulphonate group or COOR.sup.15, where R.sup.15 represents H, C.sub.1-C.sub.20 alkyl, C.sub.2-C.sub.20 alkenyl, C.sub.2-C.sub.20 alkynyl, C.sub.3-C.sub.15 cycloalkyl or aryl.

Functionalized fluorescent tracers, methods of making the tracers, and methods of using the tracers are provided. In some implementations, the fluorescent tracers include a functionalized fluorescent dye. The functionalized fluorescent dye includes an isothiocyanate-containing dye functionalized with a functional group that includes a primary amine. In some implementations, a method of tracing fluid flow in a subterranean formation includes mixing the functionalized fluorescent tracer into a fluid, flowing the tracer fluid into a subterranean formation, recovering a sample from a subterranean formation, and analyzing the sample for a fluorescent signal and a barcode functional group.

The drug tracking system may be used to screen a subject's bodily waste and to identify a drug the subject has consumed. The system includes drug tags which include a one or more food dyes, each detectable in a subject's bodily waste using photographic or absorption spectroscopic analysis. The system may further include a database in which is stored the spectral signature of each drug tag and the unique drug associated with each drug tag. A spectral analysis obtained by analyzing a bodily waste sample may be entered into the database. The database may include instructions for comparing the spectral analysis to the spectral signature of each drug tag. The instructions may further report the unique drug associated with a drug tag which has a spectral signature matching the spectral analysis.

Methods and compositions are provided that include a multichromophore and/or multichromophore complex for identifying a target biomolecule. A sensor biomolecule, for example, an antibody can be covalently linked to the multichromophore. Additionally, a signaling chromophore can be covalently linked to the multichromophore. The arrangement is such that the signaling chromophore is capable of receiving energy from the multichromophore upon excitation of the multichromophore. Since the sensor biomolecule is capable of interacting with the target biomolecule, the multichromophore and/or multichromophore complex can provide enhanced detection signals for a target biomolecule.

Method of marking a hydrocarbon liquid includes adding to the liquid, a tracer compound of Formula I or II: ##STR00001##
wherein at least one of R.sup.1-R.sup.6 in Formula I and at least one of R.sup.7-R.sup.14 in Formula II is selected from: i. a bromine or fluorine atom; ii. a partially or fully halogenated alkyl group; iii. a branched or cyclic C.sub.4-C.sub.20 alkyl group; iv. an aliphatic substituent linking two positions selected from R.sup.1-R.sup.6 in Formula I to one another or two positions selected from R.sup.7-R.sup.14 in Formula II to one another; or v. a phenyl group substituted with a halogen atom, an aliphatic group or halogenated aliphatic group and none of R.sup.1-R.sup.6 and none of R.sup.7-R.sup.14 being a sulphonate group or COOR.sup.15, where R.sup.15 represents H, C.sub.1-C.sub.20 alkyl, C.sub.2-C.sub.20 alkenyl, C.sub.2-C.sub.20 alkynyl, C.sub.3-C.sub.15 cycloalkyl or aryl.

A method of making an identifiable gypsum-based building product, includes incorporating a suitable amount of an optically identifiable marker into the product to be sensed by a conventional detecting device; applying the product with the marker in a conventional manner in the course of building construction, creating a finished building product; and analyzing the finished building product and optically detecting the presence of the marker in real time onsite.

Systems and methods are provided for authenticating working fluids. The systems and methods include exposing at least a portion of a working fluid containing a UV-reactive chemical marker to light having wavelengths in the range of about 10-400 nm, thereby causing the chemical marker to generate a signal. The signal can be detected via a sensor system and compared to a reference signal that is associated with an authentic working fluid. An output may be generated to indicate whether the working fluid is the authentic working fluid.

The drug tracking system may be used to screen a subject's bodily waste and to identify a drug the subject has consumed. The system includes drug tags which comprise a one or more food dyes, each detectable in a subject's bodily waste using photographic or absorption spectroscopic analysis. The system may further include a database comprising the spectral signature of each drug tag and the unique drug associated with each drug tag. A spectral analysis obtained by analyzing a bodily waste sample may be entered into the database. The database may include instructions for comparing the spectral analysis to the spectral signature of each drug tag. The instructions may further report the unique drug associated with a drug tag which has an spectral signature matching the spectral analysis.