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 fuel pump according to the invention includes a housing and a part, which is a moving part during operation and which bears on a housing region at least indirectly. It is proposed that the fuel pump includes a coating which is applied to the housing region on a side of the housing region which faces towards the moving part, and that the coating is composed of a plastic.

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 fuel pump according to the invention includes a housing and a part, which is a moving part during operation and which bears on a housing region at least indirectly. It is proposed that the fuel pump includes a coating which is applied to the housing region on a side of the housing region which faces towards the moving part, and that the coating is composed of a plastic.

Abstract: A fuel injection valve for internal combustion engines having a valve body in which a bore is embodied, a valve seat face, at least one injection opening embodied on the end toward the combustion chamber of the bore, and at least one injection opening connecting the bore with the combustion chamber of the engine. A nozzle needle is longitudinally displaceably guided in the bore and on its end toward the combustion chamber it has a sealing face, which cooperates with the valve seat face and thus controls the at least one injection opening. The nozzle needle has a central longitudinal bore, in which an inner needle is disposed that is fixed immovably relative to the valve body. The nozzle needle is guided over at least part of its length on the inner needle, so that the nozzle needle is kept exactly centrally in the bore at all times.

Abstract: A fuel injection valve for internal combustion engines, having a valve body (3) in which a bore (7) is embodied. A valve seat face (10) and at least one injection opening (9) are embodied on the end toward the combustion chamber of the bore (7), and at least one injection opening (9) connects the bore (7) with the combustion chamber of the engine. A nozzle needle (12) is longitudinally displaceably guided in the bore (7) and on its end toward the combustion chamber it has a sealing face (217), which cooperates with the valve seat face (10) and thus controls the at least one injection opening (9). The nozzle needle (12) has a central longitudinal bore (19), in which an inner needle (14) is disposed that is fixed immovably relative to the valve body (3). The nozzle needle (12) is guided over at least part of its length on the inner needle (14), so that the nozzle needle (12) is kept exactly centrally in the bore (7) at all times (FIG. 1).

Abstract: An electric power tool, in particular a right-angle grinder is disclosed, having an elongated motor housing in which an electric motor is received, having a gear drive housing at a first end of the motor housing to receive a gear drive for driving a working spindle, having a handle element which is fastened rotatably at a second end of the motor housing and in which a grip switch is arranged, and having air intake slots to cool the electric motor which are arranged at the second end of the motor housing. In addition, at least one baffle plate, which serves to deflect particles and can simultaneously be configured as a cooling panel for cooling electronic components, is preferably located in the flow region of the air intake slots.

Abstract: A power tool is disclosed, having an elongated motor housing in which an electric motor is received, having a gear drive housing at a first end of the motor housing to receive a gear drive for driving a working spindle, and having a handle element which is fastened rotatably at a second end of the motor housing and in which a grip switch is arranged. The handle element is rotatable with respect to the motor housing into at least four predefined angular positions that are preferably offset from one another by angles of 90°, and can be snap-locked in them.

Abstract: Modified cyclopentadiene resins comprising essentiallya) 20 to 80% by weight of cyclopentadiene compounds,b) 1 to 40% by weight of natural resin acids andc) 31 to 70% by weight of phenol resins.These compounds are suitable as binder resins for printing inks. They are distinguished by excellent compatibility with aromatics-free mineral oils and with vegetable oils.

Abstract: A continuous process for the preparation of perfluorinated carbonyl fluorides from hexafluoropropene oxide (HFPO), in which HFPO is continuously oligomerized in a catalyst solution in devices which allow separation of the heavy product phase from the catalyst phase during the reaction, is described. Different oligomer distributions can be achieved by choice of the catalyst and different operating temperatures. The reaction itself takes place always in the substantial absence of the product which is formed, and achieves a considerable saving in time.

Abstract: A process for the preparation of the dimer of hexafluoropropene oxide (HFPO), in which the HFPO is dimerized in an aprotic polar solvent in the presence of a catalyst mixture, is described. The catalyst mixture is composed of a metal salt of the elements of the 1st transition metal series of the periodic table and of a tertiary diamine. By bringing in a molar ratio of metal salt to tertiary diamine in the range from 2:1 to 1:2, in particular 1:1, the selectivity for the dimeric compound is greatest, with high yields of the dimer being obtained.

Abstract: A curing agent (A) for resins (B) which can be cured by means of isocyanates, which has an amine number of 20 to 150 mg of KOH/g and an OH number of not more than 20 mg of KOH/g and which contains per molecule at least two masked isocyanate groups which are reactive under the conditions of curing, obtained by reacting(a) an amine which contains at least one .beta.-hydroxylalkyl group per molecule and has an OH number of 100 to 1,200 mg of KOH/g and an amine number of 100 to 1,200 mg of KOH/g and which, if appropriate, also contains NHCO groups, if appropriate as a mixture with another OH-functional and/or NH-functional compound, with(b) a partly masked isocyanate, if appropriate as a mixture with an at least difunctional, OH-reactive and/or NH-reactive compound.These curing agents are readily dispersible in aqueous systems, if appropriate after neutralization, and frequently increase stability in aqueous paint formulations.

Abstract: A motor-driven machine with variable torque setting includes a motor, a planetary gearing driving a work spindle and a rotatably mounted internal gear actuating a motor de-energizer against the action of a spring force when a settable limit torque is exceeded. To achieve a compact design, a torsion spring element extending in the axial direction alongside the planetary gearing is provided for generating the spring force. The torsion spring element carries a swivel element at one end which engages a cam on the internal gear and is held at an opposite end in a support so that the swivel element can swivel out of an initial position against the action of the force of the torsion spring element to de-energize the motor.