Abstract: Raman scattering, while a powerful and versatile technique, relies of the detection of weak signals. Detecting the signal can be difficult if there is interference, especially if the interference comes from scattered stray light of the laser used to generate the Raman signal. Described here is a frequency modulation technique in combination with heterodyne detection that simultaneously rejects interference from ambient light as well as from scattered stray laser light. This provides a means to detect Raman signal and discriminate against scattered light without using an expensive and bulky spectrometer.

Abstract: Raman scattering, while a powerful and versatile technique, relies of the detection of weak signals. Detecting the signal can be difficult if there is interference, especially if the interference comes from scattered stray light of the laser used to generate the Raman signal. Described here is a frequency modulation technique in combination with heterodyne detection that simultaneously rejects interference from ambient light as well as from scattered stray laser light. This provides a means to detect Raman signal and discriminate against scattered light without using an expensive and bulky spectrometer.

Abstract: A Raman analyzer for analyzing light emitted from a Raman cell is provided that has a beam splitter configured to split the light emitted from the Raman cell into a first beam and a second beam. An atomic vapor filter can be used to filter a Raman scattered line from the first beam and a chopper system can periodically interrupt the first and second beams that are directed towards a photo detector, which can convert light from the first and second beams into an electrical signal. The signal output from the photo detector can optionally be amplified, digitized, Fourier filtered, and/or subjected to Fourier analysis.

Abstract: A Raman analyzer for analyzing light emitted from a Raman cell is provided that has a beam splitter configured to split the light emitted from the Raman cell into a first beam and a second beam. An atomic vapor filter can be used to filter a Raman scattered line from the first beam and a chopper system can periodically interrupt the first and second beams that are directed towards a photo detector, which can convert light from the first and second beams into an electrical signal. The signal output from the photo detector can optionally be amplified, digitized, Fourier filtered, and/or subjected to Fourier analysis.

Abstract: A Raman head is provided capable of operating at high surrounding pressures. The Raman head has housing having a first, sealed chamber filled with an incompressible liquid and a second chamber that is open to the surrounding environment. At least one bellows can be used to equalize pressure between the first sealed chamber and the surrounding environment. A planar side of a pair of plano-concave lens is positioned within the first chamber and the concave side of each plano-concave lens is positioned within the second chamber of the Raman head. Light emitted as a result of a laser beam in communication with the pair of plano-concave lens can be analyzed by a Raman analyzer.

Abstract: A compact, ultra-sensitive, inexpensive NIR spontaneous Raman spectrometer is presented. High sensitivity is achieved by the use of a multi-pass cell configuration combined with the electromotive properties of silicon crystal surface. A thin layer of silicon oxide chemisorbs molecules, which stick to its surface without altering their spectroscopic signatures. This new Raman spectrometer may be used to detect less than 40 ng (?0.5 n mol) of ammonium nitrate deposited on the silicon surface with the signal-to-noise ratio better than 50 during 0.1 s recording time and for an illuminated area of 2×10?8 m2. These results may be useful in many areas, for example the foundation of an extended project to record the dissolved NO3? ions in a large river such as the Mississippi.

Abstract: A compact, ultra-sensitive, inexpensive NIR spontaneous Raman spectrometer is presented. High sensitivity is achieved by the use of a multi-pass cell configuration combined with the electromotive properties of silicon crystal surface. A thin layer of silicon oxide chemisorbs molecules, which stick to its surface without altering their spectroscopic signatures. This new Raman spectrometer may be used to detect less than 40 ng (?0.5 n mol) of ammonium nitrate deposited on the silicon surface with the signal-to-noise ratio better than 50 during 0.1 s recording time and for an illuminated area of 2x10?8 m2. These results may be useful in many areas, for example the foundation of an extended project to record the dissolved NO3? ions in a large river such as the Mississippi.

Abstract: A Raman head is provided capable of operating at high surrounding pressures. The Raman head has housing having a first, sealed chamber filled with an incompressible liquid and a second chamber that is open to the surrounding environment. At least one bellows can be used to equalize pressure between the first sealed chamber and the surrounding environment. A planar side of a pair of plano-concave lens is positioned within the first chamber and the concave side of each plano-concave lens is positioned within the second chamber of the Raman head. Light emitted as a result of a laser beam in communication with the pair of plano-concave lens can be analyzed by a Raman analyzer.

Abstract: A Raman analyzer for analyzing light emitted from a Raman cell is provided that has a beam splitter configured to split the light emitted from the Raman cell into a first beam and a second beam. An atomic vapor filter can be used to filter a Raman scattered line from the first beam and a chopper system can periodically interrupt the first and second beams that are directed towards a photo detector, which can convert light from the first and second beams into an electrical signal. The signal output from the photo detector can optionally be amplified, digitized, Fourier filtered, and/or subjected to Fourier analysis.

Abstract: A battery charger includes a first pair of electrical connectors configured to couple to a positive terminal of the battery and a second pair of electrical connectors configured to couple to a negative terminal of the battery. The first pair and second pair of connectors forming Kelvin connections to the battery. A microprocessor is configured to selectively charge the battery and measure a dynamic parameter of the battery as a function of an AC signal applied to the battery.

Abstract: An apparatus for testing a storage battery includes battery test circuitry configured to perform a battery test on the storage battery. The battery test circuitry responsively provides a test result output related to a condition of the storage battery. A test count memory configured to store a test count and test count circuitry is configured to maintain a test count in response to an occurrence of a battery test performed by the battery test circuitry.

Abstract: Olefins are converted to alcohols and/or ethers employing, as catalyst, an acidic zeolite which has been bound with an essentially non-acidic refractory oxide of at least one metal of Group IVA and/or IVB of the Period Table of the Elements, e.g., silica, titania, zirconia and/or germania.

Abstract: A process for converting light olefin to alcohol(s), ether(s) or mixtures of alcohol(s) and ether(s) which comprises contacting a feed containing at least one light olefin with water in the vapor and/or liquid phase under olefin hydration conditions in the presence of acidic zeolite MCM-22 as olefin hydration catalyst to produce said alcohol(s) and/or ether(s).

Abstract: A feedstock containing one or more C.sub.9 + aromatic compounds, and optionally benzene and/or toluene, undergoes conversion over a catalyst comprising a zeolite possessing a Constraint Index of from 1 to about 3 to provide a product containing a substantial amount of C.sub.6 -C.sub.8 aromatic compounds, e.g. benzene and xylene(s), predominantly the latter.

Abstract: A process for converting propylene to isopropyl alcohol by contacting water with a propylene-containing feed at a mole ratio of water to propylene of at least about 0.5:1 (water:olefin), usually about 1:1-10:1 in the vapor and/or liquid phase under propylene hydration conditions. The hydration is carried out in the presence of a relatively constrained intermediate pore size zeolite such as ZSM-35 or ferrierite as the hydration catalyst. The zeolite is used in the acid form and with a crystal size of not more than 0.2.mu. to give high activity for conversion to isopropyl alcohol.

Abstract: A moderate pressure hydrocracking process in which a highly aromatic, substantially dealkylated feedstock having a boiling point in the range between 300.degree. and 650.degree. F. is processed directly to high octane gasoline by hydrocracking over a catalyst, preferably comprising a large pore size, crystalline alumino-silicate zeolite hydrocracking catalyst such as zeolite Y together with a hydrogenation-dehydrogenation component. The feedstock which is preferably a light cut light cycle oil has an aromatic content of at least 50, usually at least 60 percent and an API gravity not more than 25. The hydrocracking typically operates at 600-1000 psig at moderate to high conversion levels to maximize the production of monocyclic aromatics which provide the requisite octane value to the product gasoline.

Abstract: A moderate pressure hydrocracking process in which a highly aromatic, substantially dealkylated feedstock having a boiling point in the range between 300.degree. and 650.degree. F. is processed directly to high octane gasoline by hydrocracking over a catalyst, preferably comprising a large pore size, crystalline alumino-silicate zeolite hydrocracking catalyst such as zeolite Y together with a hydrogenation-dehydrogenation component. The feedstock which is preferably a light cut light cycle oil has an aromatic content of at least 50, usually at least 60 percent and an API gravity not more than 25. The hydrocracking typically operates at 600-1000 psig at moderate to high conversion levels to maximize the production of monocyclic aromatics which provide the requisite octane value to the product gasoline.

Abstract: Olefins undergo conversion in the presence of water and recycled alcohol to a mixture of alcohol and ether which is then subjected to various downstream operations including distillation and extraction or decantation to provide an ether-rich product containing little if any alcohol or water. The foregoing process is especially suitable to the conversion of propylene and propylene-containing streams to diisopropyl ether which is useful, inter alia, as an octane improver for gasoline.

Abstract: Light olefin is introduced at multiple points of entry into a conversion unit subdivided into first and second reaction zones. Reaction of olefin with water takes place in the first reaction zone under conditions intended to promote the production of alcohol therein and in the second reaction zone, alcohol produced in the first reaction zone is both dehydrated and reacted with olefin under conditions intended to promote the production of ether therein. The same or different shape selective acidic zeolites are employed as catalysts in both reaction zones.

Abstract: Disclosed are methods for upgrading lube oil base stocks comprising the steps of hydrocracking such materials, preferably under relatively moderate conditions, and subsequently separating the hydrocracked materials to produce in an aromatic rich extract stream and an aromatics lean raffinate stream. The separation step is preferably achieved by solvent extraction of at least a portion of the hydrocracked material. The stream comprising the aromatic rich extract is then catalytically cracked under fluidized conditions to produce gasoline and other distillates. The aromatics lean raffinate stream is further processed by dewaxing and/or the like to produce relatively high volume metric yields of low viscosity lube oil having improved viscosity-temperature characteristics.