Abstract: An electrophoresis instrument includes a capillary tube mounted in an air cooled cartridge. The cartridge also supports a spherical lens which is part of the optical detection apparatus. The cartridge rests in a manifold which includes the sample and buffer reservoirs. The temperature of the capillary tube is controlled by measuring the electrical resistance of the capillary tube during the electrophoresis process and then cooling or heating the cartridge by circulating temperature controlled air over the tube. The optical path associated with the instrument is a fiber optic bundle bifurcated close to dual detectors into a reference arm and a sample arm so as to provide similar reference and sample optical paths. The instrument may be used for temperature control for buffer gradient electro-phoresis and also, a neutral marker for determining electro-osmotic flow may be detected.

Abstract: A method for determining the concentration of individual solutes in a body of liquid, e.g., measuring contaminants in waste water. A sparging IR process is used, in which gas in the form of minute bubbles moves upwardly in a non-flowing body of liquid. The gas remove vaporized samples of the subject solutes and flows to a gas cell, where it is subjected to infrared spectrometer analysis. The true concentration of each subject solute is measured by plotting its concentration values against elapsed time, and then extrapolating back to time zero to determine the initial concentration of the solute. In addition, the rate of depletion is used to determine the ratio of vapor pressure to solubility of the solute. Replotting the original data using logarithm values can simplify the extrapolation.

Abstract: A retraction mechanism permits easily removing a sensor assembly from a pressurized process fluid container through a valve attached to an opening in the container. The retraction mechanism includes a folding support linkage having a first end and a second end formed from at least two links that are joined together to have a pivot joint located therebetween. The first end of the support linkage is joined to the sensor assembly, while the second end of the support linkage is joined to the valve or the fluid container. The two links are partially folded when the sensor assembly is in operable position, and pivot about the pivot joint to unfold when the sensor assembly is removed. The retraction mechanism further includes a damper connected between the two links of the support linkage. The damper provides a damping or restraining force for the sensor assembly as the sensor assembly is removed from the fluid container.

Abstract: A remote gas measuring apparatus and method utilizes the optical absorption line characteristics to determine an amount of gas of interest as may exist in an area under study. The remote gas measuring apparatus includes a source of electromagnetic radiation that can be projected toward the area in question and a light collecting arrangement. The light signal received is coupled to a fast light switch modulator which modulates the light signal to a first frequency. A second modulating arrangement modulates the light signal to a second frequency and includes a birefringent etalon device having a periodic spacing equal to the periodicity of the absorption lines of the gas of interest. The second modulating means is further effective such that, when an electric field is applied thereto the transmission spectra associated with the light signal is shifted between spectra which coincide with the absorption lines and spectra which fall between the absorption lines.

Abstract: A gas cell for use in spectrometric analysis is disclosed, in which a series of pipes provide both the gas chamber and a light guide for infrared radiation which passes through the gas to accomplish the analysis. The light pipe is designed to provide a maximum radiation throughput of a collimated radiation beam. The same pipe provides laminar gas flow into and out of the gas cell. In other words, the gas when moving is not obstructed or restricted by changes in the cross-sectional area of its passageway.

Abstract: An ATR sample cell is disclosed, of the type incorporating a circular internal reflectance crystal. A flowing liquid sample has input and output ports in the IRE housing, or cell, which are offset from the axis of the circular IRE (or rod) sufficiently to direct the flow of liquid against the internal wall (usually stainless steel) of the flow jacket, rather than against the IRE. This tends to create a helical flow path from the input port at one end of the housing to the output port at the other end of the housing. In order to further control the sample flow path, and augment the spiraling effect, two further improvements are disclosed. The structure through which the sample material enters the sample chamber surrounding the IRE is designed to establish a spiraling motion of the liquid flow before it enters the sample chamber. Also, the inner cylindrical wall of the metal housing has a groove which forms a helical path from the input to the output end.

Abstract: A radiation guiding structure for incoherent radiation is disclosed in which a collimated beam is transmitted through a light pipe having high radition throughput. Radiation losses due to absorbance are minimized by: (1) matching the area of the beam and the light pipe passage; (2) minimizing the number of reflectances of a given ray by reducing the angular divergence of radiation in the beam; and (3) using a reflective coating on the wall of the light pipe which has the low point of its reflectance curve at a relatively high grazing angle.

Abstract: A probe is disclosed for use in internal reflection spectroscopy at locations immersed in containers. Two parallel light pipes, located inside the probe, are used to carry radiation toward and away from an internal reflectance element (IRE) located at or near the bottom of the probe. The IRE, which is exposed to analyte in the container, has a radiation-entering surface and a radiation-exiting surface which permit collimated radiation to fill both light pipes. No beamsplitter is required to separate pre-sample and post-sample radiation. In one embodiment the IRE is a rod having concave conical entering and exiting surfaces, and a separate radiation-direction-reversing element is mounted on the tip of the probe. In another embodiment the IRE is itself a direction-reversing means mounted on the tip of the probe.

Abstract: An external reflectance spectroscopy apparatus and method are disclosed in which maximum radiation througput is obtained by using a beamsplitter which reflects half of a collimated beam and transmits the other half. In order to obtain reliable results, the condition of perpendicular incidence on the sample is approximated (without limiting throughput) by providing a beamsplitter having an uneven number of reflecting blades and the same number of transmitting openings. Each reflecting blade is opposite to an open area having the same size and shape. The result is a substantial equalizing of contributions from rays polarized parallel to the plane of incidence and from rays polarized perpendicular to the plane of incidence.

Abstract: An apparatus and method for fluid sample analysis are disclosed which use a cylindrical internal reflectance element (IRE) having conical end surfaces. The divergence of rays inside the IRE is minimized by using reflecting cones at each end of the IRE, the structural elements and their dimensions being such that each entering ray strikes the conical IRE end surface at substantially the same angle of incidence. Means are included for providing optical stops at the large end of both the input and output reflecting cones, in order to eliminate any rays which might travel through the IRE without first being reflected by the input cone. Using such stops and properly dimensioning the entering diameter of the reflecting cone, result in a system in which each ray entering the IRE has been reflected once, and only once, by the reflecting cone.

Abstract: Solvent composition gradients in high performance liquid chromatography (HPLC) are generated with a packed bed gradient generator. Natural dispersion occurs in flow through a bed of particles due to eddy and molecular diffusion. This dispersion changes a sharply defined front between two solvents into a desirable error function type gradient profile at the interface between the solvents. The packed-bed gradient generator is a cylindrical tube filled with chemically inert glass beads. Other axial column contours such as a double taper column or bell-shaped entrance and exit regions can be used to tailor the gradient profile. The static packed-bed gradient generator can be placed either on the low pressure inlet side of the high pressure pump, or the high pressure outlet side of the pump. While low pressure operation may provide added convenience, high pressure operation provides additional pulse dampening ability.

Abstract: A high speed, downwind horizontal axis wind turbine includes three circumferentially spaced lightweight blades having inner support arms and radially outwardly disposed airfoil configured blade segments which are pivotally connected to the support arms, so as to fold straight downwind under high wind conditions or high rotating speeds. A spring biased control mechanism serves to rotate the airfoil segment of each blade about its longitudinal axis as the blade is folded downwind, so that a simultaneous folding and feathering action is obtained to prevent damage to the turbine in high wind conditions or under high rotating speeds.

Abstract: Communications security between a host computer and another remote computer or terminal is ensured by a means of a two-tiered cryptographic communications security device and procedure. A master key is used to encrypt a first session key. The session key encrypted under the master key is transmitted from a remote facility to a host computer. At the host computer, the session key is decrypted and stored, a second and different session key is then generated, encrypted under the master key and transmitted to the remote facility where it is utilized as the facilities session decryptor key. Because the session key utilized for transmission of data between the remote facility and the host differs from the session key utilized for transmission of data between the host and the remote facility, communications security is increased.

Abstract: A scanning spectrometer incorporating a scanning diode laser powered with a controllable injection current. The injection current control may be set at predetermined discrete levels. These levels may be varied in accordance with signals derived from a servo loop, and may have superimposed upon them a cyclically varying substantially constant amplitude current. The laser output is directed via a beam splitter to both sample and reference cells. The material in the reference cell is so selected as to provide absorption features at each of the desired frequencies. The cyclically varying current is provided with an amplitude sufficient to cause a frequency amplitude at least as great as the maximum breadth of each of these spectral features of interest. The preselected bias currents are selected so as to provide lasing action of the diode at or near each of the selected frequencies.

Abstract: Radiating mirror lasers in which a semiconductor active element containing an appropriately fabricated heterostructure configuration is formed as one end mirror of a two-mirror resonant cavity. The active element is fabricated from an alloy semiconductor compound such a lead salt alloy, the bandgap of which may be varied by varying the relative composition of its constituents. By properly selecting the compound and its composition, lasers may be made for operation at wavelengths that span the ultraviolet, visible and infrared portions of the spectrum. The lasers combine the inherently high power characteristics of a radiating mirror structure with a wide spectral coverage. Arrangements are disclosed for increasing power efficiencies, for tuning the operating wavelength over a wide range and for otherwise improving the utility of the lasers.

Abstract: A torque limiting device employing a clutch disposed within a cylindrically shaped housing and coupling first and second members coaxially mounted in the respective ends of the cylindrically shaped housing. The first and second members are rotatably mounted in the housing and adapted for engagement with the torqueing device and work respectively or vice versa. Manual rotation of one housing section relative to the other housing section adjusts to predetermined maximum value the torque which is transmitted the device, viz., between the first and second members. To enable bidirectional torque limiting, a third member is disposed between said first and second members.

Abstract: A concentrating vortex shaker for the simultaneous shaking and concentration of a multiplicity of liquid samples comprises a heat-conductive block having a plurality of openings for receiving laboratory vessels containing sample liquids and removably mounted on a base provided with an adjustable eccentric drive for displacing the block in a gyrating motion. An airtight cover is removably mounted on the block and forms a chamber above the samples which can be controllably evacuated. The samples can be heated or cooled by a temperature-controlled liquid which is fed through a channel formed in the block or heated by an adjustable electrical heater provided in the block mounting or cooled by a cooling plate, upon which the block mounts.

Abstract: A fraction collector or other electrically operated liquid-handling device has a tray underlying the device for collecting spilled liquid. A pitched surface in the tray gathers any spilled liquid into the vicinity of a sensor having a moisture-destructible or sensitive element which holds a switch against the force of a spring in a closed-circuit position, allowing power to be fed from a current source to the electrically operated device. Upon wetting and destruction of the element the spring is relieved to open the switch, thereby cutting off the power and stopping the operation of the liquid-handling device.

Abstract: A torque limiting device employing a clutch disposed within a cylindrically shaped housing and coupling first and second members coaxially mounted in the respective ends of the cylindrically shaped housing. The first and second members are rotatably mounted in the housing and adapted for engagement with the torqueing device and work respectively or vice versa. Manual rotation of one housing section relative to the other housing section adjusts to predetermined maximum value the torque which is transmitted through the device, viz., between the first and second members.