Abstract: A device includes a housing having a bore formed axially therethrough. The housing includes a stop that protrudes radially inward proximate to a lower end of the housing. The device also includes a lower piston positioned in the bore. The lower piston is configured to move axially within the bore in response to a pressure differential across the lower piston. The lower piston is prevented from passing out through the lower end of the housing by the stop. The lower piston has a lower piston hole formed therethrough. The device also includes an upper piston positioned in the bore. The upper piston is configured to move axially within the bore in response to a pressure differential across the upper piston. The upper piston has an upper piston hole formed therethrough. The device is configured to receive a fluid in the bore, between the upper and lower pistons.

Abstract: A blood sample processor for imaging a centrifuged blood sample is provided including a transparent container with the centrifuged blood sample therein. An illumination source is positioned to illuminate the centrifuged blood sample at a non-right angle to the transparent container. A digital camera disposed opposite the transparent container images the centrifuged blood sample and the image is processed to determine the relative locations of component layers of the centrifuged blood sample.

Abstract: Provided is a biological sample imaging device and a biological sample imaging method that are capable of disposing a sufficient number of large-sized particles in a biological sample so as to be moderately dispersed within an imaging range. The biological sample imaging method includes: a first step of introducing a biological sample containing particles into a liquid flow channel; a second step of causing the biological sample introduced into the liquid flow channel to flow in a forward direction; a third step of causing the biological sample to flow in a reverse direction after the second step; and an imaging step of taking, in an imaging cell, images of the particles contained in the biological sample that remains in the liquid flow channel after the third step.

Abstract: The present invention provides methods for producing cannabinoids and cannabinoid analogs as well as a system for producing these compounds. The inventive method is directed to contacting a compound according to Formula I or Formula II with a cannabinoid synthase. Also described is a system for producing cannabinoids and cannabinoid analogs by contacting a THCA synthase with a cannabinoid precursor and modifying at least one property of the reaction mixture to influence the quantity formed of a first cannabinoid relative to the quantity formed of a second cannabinoid.

Abstract: Thermal conductivity measurements of a wellbore fluid may be used to derive the sag of the wellbore fluid (i.e., the inhomogeneity or gradation in particle distribution in the fluid as a result of the particles settling). For example, a method may include measuring a thermal conductivity of a fluid at two or more locations along a height of a vessel containing the fluid that comprises particles dispersed in a base fluid; and calculating a sag of the fluid based on the thermal conductivity at the two or more locations. In some instances, the temperature and pressure of the wellbore fluid may be changed and/or the wellbore fluid may be sheared to investigate their effects on sag.

Abstract: A device and method for filtering blood is disclosed herein. The device can filter blood and attach analytes within the blood to magnetic particles. The analytes can then be strongly bound to an analyzing device by a magnetic force. The analytes can then be counted by the analyzing device and the result can be displayed.

Abstract: A system and method are provided for determining the health of an engine. The method includes a plurality of standard noise spectra collected from engines with known defects. A noise spectrum of the engine being monitored is sensed and compared to the plurality of standard noise spectra from the engines with known defects. From the comparison, a type and a degree of defect is identified based upon the comparison.

Abstract: A measurement device measures a liquid flow discharged from a funnel in a lower branch and/or a side branch. A modelling function is established between liquid flows received with the funnel and/or liquid flows discharged through the lower branch and/or the side branch. In drainability measurement, a sensor measures the flow through a wire out of a measurement chamber at least at two points in time. A processor establishes a parameter descriptive of the drainability from flows measured at the different points in time based on a modelling function stored in a memory.

Abstract: The invention relates to a novel method for determining or measuring the content of at least one filter aid in an un-filtered product.

Abstract: Systems and methods for direct and indirect measurement of the density of a fluid which exhibits sag characteristics is disclosed. The sag measurement system includes a test container for holding a fluid mixture to be analyzed and a suction port on the test container. A pump is coupled to the suction port for circulating the fluid mixture from the test container through a circulation loop. A measurement device is coupled to the circulation loop and a return port directs the fluid mixture from the circulation loop back to the test container at substantially the same vertical location as the suction port. The fluid mixture flowing through the circulation loop passes through the measurement device before returning to the test container through the return port. The measurement device is operable to monitor the particle distribution of the fluid mixture as it changes due to gravity.

Abstract: Provided is a method for analyzing a dispersion made by dispersing a liquid or solid dispersoid into a liquid dispersion medium. The method includes the steps of: preparing a sample liquid from the dispersion by forming an agglomerate of the dispersoid in the dispersion medium; redispersing the dispersoid that forms the agglomerate in the sample liquid into the dispersion medium of the sample liquid; and measuring the amount of the dispersoid that has been redispersed from the agglomerate in the sample liquid.

Abstract: The Invention relates to a method for determining the filterability of beer, said method having the following steps: a) taking a wort or beer sample, b) filtering the sample on a plurality of filters of varying pore size, c) determining the size of the particles on the filter surfaces of the filters, d) qualitative analysis of the particles on the filter surfaces and assigning the measured particles to certain substances or groups of substances present in beer or the wort, wherein evidence on the filterability can be obtained from the size of the particles of different substances or groups of substances of individual fractions.

Abstract: Systems and methods for direct and indirect measurement of the density of a fluid which exhibits sag characteristics is disclosed. The sag measurement system includes a test container for holding a fluid mixture to be analyzed and a suction port on the test container. A pump is coupled to the suction port for circulating the fluid mixture from the test container through a circulation loop. A measurement device is coupled to the circulation loop and a return port directs the fluid mixture from the circulation loop back to the test container at substantially the same vertical location as the suction port. The fluid mixture flowing through the circulation loop passes through the measurement device before returning to the test container through the return port. The measurement device is operable to monitor the particle distribution of the fluid mixture as it changes due to gravity.

Abstract: Systems and methods for direct and indirect measurement of the density of a fluid which exhibits sag characteristics is disclosed. The sag measurement system includes a test container for holding a fluid mixture to be analyzed and a suction port on the test container. A pump is coupled to the suction port for circulating the fluid mixture from the test container through a circulation loop. A measurement device is coupled to the circulation loop and a return port directs the fluid mixture from the circulation loop back to the test container at substantially the same vertical location as the suction port. The fluid mixture flowing through the circulation loop passes through the measurement device before returning to the test container through the return port. The measurement device is operable to monitor the particle distribution of the fluid mixture as it changes due to gravity.

Abstract: A method and apparatus for measuring dissolved residue concentrations and particulate residue particle concentrations and size distribution in liquids, particularly colloidal suspensions. The method involves separating dissolved and particulate residues in liquids for subsequent analysis of the residue species. The method includes the steps of forming an aerosol from the liquid sample to be analyzed, evaporating the droplets in the aerosol to dryness, detecting and sizing the particles, and determining the liquid volumetric inspection rate. An apparatus for separating dissolved and particulate residues in liquids for determination of the concentrations of the two residue species as well as the size distribution of the particulate species is also disclosed. The apparatus includes a droplet former, a dryer communicatively connected to the droplet former, and a detector communicatively connected to the evaporator for detecting and sizing particles.

Abstract: Systems and methods for direct and indirect measurement of the density of a fluid which exhibits sag characteristics is disclosed. The sag measurement system includes a test container for holding a fluid mixture to be analyzed and a suction port on the test container. A pump is coupled to the suction port for circulating the fluid mixture from the test container through a circulation loop. A measurement device is coupled to the circulation loop and a return port directs the fluid mixture from the circulation loop back to the test container at substantially the same vertical location as the suction port. The fluid mixture flowing through the circulation loop passes through the measurement device before returning to the test container through the return port. The measurement device is operable to monitor the particle distribution of the fluid mixture as it changes due to gravity.

Abstract: A method for quantifying the quality degradation of individual stored red blood cell (RBC) units, thereby yielding information to improve decisions regarding their respective allocation, patient suitability, and use. The method comprises: a hemolysis step; an optical analysis step; and a computation step. The method is amenable to clinical implementation as well as indicative of any given unit's relative viability and thus prospective efficacy. This would provide clinicians with actual data on RBC quality when making decisions about which and how many units to use for transfusion of a given patient. Moreover, deploying this testing throughout the supply chain will improve distribution, planning, and inventory control decisions. A vital aspect of this testing method is the accumulation of copious output and other associated data and the mathematical analyses thereof to optimize algorithms by which to characterize each subsequent test output as meaningfully as possible.

Abstract: The present invention describes a system and method for accurately measuring the concentration of a substance within a filter housing. A concentration sensor and a communications device are coupled so as to be able to measure and transmit the concentration of a particular substance within the filter housing while in use. This system can comprise a single component, integrating both the communication device and the concentration sensor. Alternatively, the system can comprise separate sensor and transmitter components, in communication with one another. In yet another embodiment, a storage element can be added to the system, thereby allowing the device to store a set of concentration values. The use of this device is beneficial to many applications. For example, the ability to read concentration values in situ allows integrity tests to be performed without additional equipment.

Abstract: The present invention describes a system and method for accurately measuring the concentration of a substance within a filter housing. A concentration sensor and a communications device are coupled so as to be able to measure and transmit the concentration of a particular substance within the filter housing while in use. This system can comprise a single component, integrating both the communication device and the concentration sensor. Alternatively, the system can comprise separate sensor and transmitter components, in communication with one another. In yet another embodiment, a storage element can be added to the system, thereby allowing the device to store a set of concentration values. The use of this device is beneficial to many applications. For example, the ability to read concentration values in situ allows integrity tests to be performed without additional equipment.

Abstract: A transfer structure for droplet-based microfluidic analysis is characterized by a first conduit containing a first stream having at least one immiscible droplet of aqueous material and a second conduit containing a second stream comprising an aqueous fluid. The interface between the first conduit and the second conduit can define a plurality of apertures, wherein the apertures are sized to prevent exchange of the first and second streams between conduits while allowing lossless transfer of droplets from the first conduit to the second conduit through contact between the first and second streams.

Abstract: The present invention relates to a collection device for a substance, and methods related to collecting thereof.

Abstract: A system for testing a drilling fluid including a vessel having a fluid inlet, a filtrate outlet, a fluid outlet, and at least one permeable media disposed within the vessel. The system further including a base fluid container in fluid communication with the fluid inlet, a test fluid container in fluid communication with the fluid inlet, a filtrate container in fluid communication with the filtrate outlet, and a collection container in fluid communication with the fluid outlet.

Abstract: The invention provides a simple, inexpensive, accurate, and rapid method of measuring particle settling velocity comprising: (i) providing a gravity settler such as a column; (ii) filling the column with a first homogenous particle suspension, wherein the particle concentration in the first homogenous particle suspension is X, (iii) separating the column into an upper sub-column and a lower sub-column with a height h after settling the first homogenous particle suspension for a period of time t, wherein some particles remain in the upper sub-column; (iv) removing the particle suspension in the upper sub-column and mixing the particle suspension confined in the lower sub-column with a height h to prepare a second homogenous particle suspension; (v) measuring the particle concentration in the second homogenous particle suspension X; and (vi) determining the particle settling velocity v with the formula: v=h(X?X)ltX. Also provided are device and system for carrying out the method.

Abstract: The invention relates to a novel method for determining or measuring the content of at least one filter aid in an unfiltered product.

Abstract: The invention concerns test elements, in particular diagnostic test elements, for determining the presence or concentration of biological, medical or biologically or medically effective substances including nucleic acids, proteins, viruses, microorganisms and cells, characterized in that these test elements contain nanofibers.

Abstract: The embodiments relate to an apparatus and a method for detecting liquids or substances from liquids in spatially separate reaction zones. The embodiments further relate to the use of the apparatus in a plug-in module or a chip card which can be used for rapid immunological tests, for example, with the help of a reading device. The liquids or substances from liquids are detected by means of a sensor array which includes at least two sensors and on which at least one diaphragm is arranged. Individual sensors are spatially separated from each other on a plane by means of walls. The diaphragm can be filled with liquid that is to be analyzed. Sealed reaction chambers are created when pressure is applied to the diaphragm. Pores in the diaphragm are completely closed in the zone of the walls while the pores are merely reduced in size and liquid can continue to be exchanged in zones directly above the sensors.

Abstract: A method and apparatus for analyzing sag in drilling fluids or solid bearing fluids wherein a cylindrical high-pressure cell assembly (80) capable of withstanding high pressure and high temperature with a coaxial cylindrical rotor (33) driven to rotate inside cell assembly (80), a sample port (12) for testing sample subtraction used for further analysis, and a sample inlet port (74) for adding testing sample. This said cell assembly (80) is supported on a pivotal cell support (90) so that it can be tilted and fixed at any angle.

Abstract: An agitation system including a motor that is capable of measuring the torque output of the motor required to mix a suspension. The motor is attached to an agitator which is placed in a suspension to be measured. The agitator is placed in the suspension and the agitation system is turned on for a period of time. This period determined by the type of agitator used and the characteristics of the suspension. When the suspension is well mixed and the torque measurement on the agitator becomes stable, the agitation system is stopped. The suspension is allowed to sit without agitation for a period of time and the agitation system is started again. After a period of time the agitation system is started and the amount of torque needed to begin turning the agitator is measured.

Abstract: Method for safely inspecting an atmospheric storage tank, located above ground or on a floating vessel, without having to empty the tank. The method employs an explosion proof robot whose explosion proof character is assured by explosion proof design and monitoring the pressure within and outside the robot throughout the inspection. Operation of the robot will cease if the pressure within the robot falls below the pressure external the robot.

Abstract: The present invention provides a technique for crystallizing a desired protein at a high probability; namely, a protein crystallizing agent and a method of crystallizing protein. The present invention also provides a technique for determining the conditions for protein crystallization easily with high efficiency; namely, a method of screening the conditions for protein crystallization and a protein crystallization screening reagent. As the protein crystallizing agent, at least one compound selected from the group consisting of a basic amino acid, acidic amino acid, ester derivative of amino acid and amide derivative of amino acid is used, or at least one of these compounds is used in combination with another protein crystallizing agent.

Abstract: A system for early detection of component failure in a hydraulic system comprises a particle detection device disposed in a fluid flow channel of a machine, the particle detection device configured to monitor a current particle count associated with fluid flowing through the fluid flow channel. The system further includes a condition monitoring system in wireless data communication with the particle detection device. The condition monitoring system is configured to receive data indicative of the current particle count and analyze historic particle count data collected by the particle detection device. The condition monitoring system is also configured to estimate a trend in the historic particle count data based on the analysis. A failure event associated with one or more components associated with the fluid flow channel is predicted if the data indicative of the current particle count deviates from the trend by a threshold amount.

Abstract: The disclosure provides a process for recycling ore in the chloride process, without the build-up of silica-containing gangue in the chlorination reactor.

Abstract: An apparatus and method to determine analytes in a fluid. One aspect of the present invention is for the determination of the oil content of water using UV, near-IR, IR or Raman spectroscopy or radiometry. In certain embodiments, a solid membrane material absorbs analytes from fluid brought into contact with it. The membrane is subsequently placed in a FTIR spectrometer, which spectrometer is enabled to determine the concentration of analytes in fluid by calibration. Certain embodiments can determine the type of hydrocarbon present, and thus can differentiate Total Petroleum Hydrocarbons (TPH) from Total Oil and Grease (TOG), without any separate sample preparation.

Abstract: A conductive fluid detection apparatus for detecting moisture mixed into a coolant comprises: a filter unit having a tubular member through which a coolant can flow, mesh members made of stainless steel etc. and filter paper through which the coolant can pass, but which can hold moisture, the mesh members and the filter paper provided and stacked inside the tubular member, the filter paper interposed between the mesh members; a resistance value measurement circuit measuring the resistance value between mesh members; and a relay stopping the supply of power to the pump when the resistance value between the mesh members falls.

Abstract: A system for early detection of component failure in a hydraulic system comprises a particle detection device disposed in a fluid flow channel of a machine, the particle detection device configured to monitor a current particle count associated with fluid flowing through the fluid flow channel. The system further includes a condition monitoring system in wireless data communication with the particle detection device. The condition monitoring system is configured to receive data indicative of the current particle count and analyze historic particle count data collected by the particle detection device. The condition monitoring system is also configured to estimate a trend in the historic particle count data based on the analysis. A failure event associated with one or more components associated with the fluid flow channel is predicted if the data indicative of the current particle count deviates from the trend by a threshold amount.

Abstract: A differential rate rotary thickener; a power detector which is disposed in a sludge receiver tank for thickened sludge thickened in the differential rate rotary thickener; a discriminator which receives an electric signal for a thickened sludge concentration (X) detected by the power detector and which calculates and discriminate the data; a first controller which receives an instruction signal being a discriminated result in the discriminator and which operates an outer cylinder driving machine and a screw driving machine; a ratio setter which receives a discriminated signal of the discriminator and which increases or decreases a chemical feed rate (?) of flocculant stepwise; and a second controller which receives an instruction signal from the ratio setter and which operates a flocculant-feeding pump are provided. Thickening of sludge is performed by controlling the chemical feed rate (?), a rotational speed (S) of a screw, and a rotational speed (C) of an outer cylinder screen.

Abstract: The invention provides methods of removing chemical species likely to lead to fuel filter plugging from a biodiesel fuel. The invention also provides biodiesel fuels and fuel blends made by these methods. Additionally, the invention provides methods of testing a biodiesel fuel for the presence of these chemical species and evaluating the quality of the fuel and its propensity to plug fuel filters based on the results of this testing.

Abstract: A device and method for detecting anthrax or other pathogens are disclosed. Individual self-contained monitoring devices of a monitoring system can be portable or stationary (e.g. installed in air ducts or plumbing of buildings) and can be part of a network of devices. Monitoring devices may be used for the detection of a variety of airborne or surface pathogens, including but not limited to anthrax, smallpox, and Salmonella. Bioamplification-coupled proteomics assays provide rapid and reliable detection of pathogens, with self-checking capabilities reducing or eliminating false positives and false negatives. Sample preservation capability allows pathogen samples to be preserved after detection for further testing. The device of the invention can be remotely operated by minimally trained technicians or security personnel.

Abstract: A system for determining properties of settling suspensions includes a settling container, a mixer, and devices for ultrasonic interrogation transverse to the settling direction. A computer system controls operation of the mixer and the interrogation devices and records the response to the interrogating as a function of settling time, which is then used to determine suspension properties. Attenuation versus settling time for dilute suspensions, such as dilute wood pulp suspension, exhibits a peak at different settling times for suspensions having different properties, and the location of this peak is used as one mechanism for characterizing suspensions. Alternatively or in addition, a plurality of ultrasound receivers are arranged at different angles to a common transmitter to receive scattering responses at a variety of angles during particle settling. Angular differences in scattering as a function of settling time are also used to characterize the suspension.

Abstract: Methods and apparatus for measuring sag properties of a drilling fluid using a rotary viscometer. An insert, or shoe, is placed at the bottom of the heat cup containing the fluid to be tested. A rotating cylinder is disposed within the fluid and solid particles are allowed to settle toward the bottom of the heat cup. The shoe incorporates a curved and inclined upper surface that directs the settled particles toward a well non-centrally located in the shoe. As the test is performed, fluid samples can be withdrawn from the well and analyzed. The samples can then be returned to the well and the test continued. The insert concentrates the settled solids into a single location, which increases the sensitivity of the test and provides a location for sample acquisition that is easily and repeatedly located, which allows for improved correlation with laboratory and flow loop results.

Abstract: Methods and apparatus for measuring sag properties of a drilling fluid using a rotary viscometer. An insert, or shoe, is placed at the bottom of the heat cup containing the fluid to be tested. A rotating cylinder is disposed within the fluid and solid particles are allowed to settle toward the bottom of the heat cup. The shoe incorporates a curved and inclined upper surface that directs the settled particles toward a well non-centrally located in the shoe. As the test is performed, fluid samples can be withdrawn from the well and analyzed. The samples can then be returned to the well and the test continued. The insert concentrates the settled solids into a single location, which increases the sensitivity of the test and provides a location for sample acquisition that is easily and repeatedly located, which allows for improved correlation with laboratory and flow loop results.

Abstract: The invention relates to a device and a method for monitoring the dispersibility of solid formulations. The single-measurement method involves measuring the course of the dispersibility of a sample in a fluid over time. The build-up measurement method involves detecting hard particles in a dispersion. The device according to the invention is equipped with a pump, a flow meter, a charging receptacle for the sample, and a filter element, all of which are connected to each other via a fluid circuit, wherein the filter element is arranged downstream behind the charging receptacle with respect to the direction of flow as predetermined by the pump.

Abstract: A method and device for detecting an accumulation (9) of a solid material in a vessel (2) that contains at least one fluid phase. The device comprises an electric conductor element (10) that is positioned in a region inside the vessel (2) where the accumulation (9) is likely to occur, the electric resistance of the conductor element (10) being a function of the temperature thereof, and means (12) for providing electrical power to the conductor element (10) and means (13) for measuring the electrical resistance of the conductor element (10).

Abstract: A system and method of measuring a level of settled particles in a fluid-containing vessel includes the steps of fluidizing particles from a position below the settled level of particles, and measuring a static pressure of liquid within the vessel at a position in the vessel below the settled level of particles. The fluidized static pressure is correlated to a level of settled particles within the vessel using an experimentally determined relationship. The apparatus includes an inlet pipe into the vessel at a position below the settled level of particles, and a pump which recirculates liquid from the vessel above the submerged level of particles, remote from the settled level of particles, and a static pressure instrument connected to the inlet pipe. A solids pump can be activated to remove settled particles from the vessel, the operation of the pump being controlled by the measured level of settled particles.

Abstract: A method and device for performing fluid analysis by separating cells and/or particles from a fluid, such as a biological, vehicular or industrial fluid. The device is a micromachined filtering device comprising a substrate with through-thickness vias having approximately equal diameters that prevent passage through the substrate of a first material while permitting passage through the substrate of other materials having diametrical dimensions less than the diameter of the vias. Electrodes are located on a surface of the substrate between vias so that as the first material collects at the surface of the substrate, the electrodes become electrically connected to produce an output signal in some proportion to the amount of the first material collected. The device can incorporate multiple micromachined substrates, yielding an analysis system that produces an electrical output for each of a number of properties or parameters.

Abstract: The invention is a system and method to rate refinery feed stocks for the formation of deposits on solid refinery surfaces.

Abstract: An apparatus and method are disclosed for measuring or analyzing dynamic and static sag caused by settling of weighting materials in drilling fluids or other solids bearing fluid. The apparatus comprises a tube and shear shaft assembly that allows for a controlled rate of shear to be applied to a sample of the fluid for testing. During a test, the assembly is placed on a pivotal holder at an angle. The assembly has pistons at the pivot center of the assembly which accommodate expansion and contraction of the test fluid due to changes in temperature and pressure, thereby allowing the test fluid to be heated, cooled and pressurized to simulate subterranean wellbore conditions without changing the center of mass of the test fluid. When weight material settles down the inclined assembly, the center of mass of the assembly changes resulting in changing torque or moment about the pivotal holder. The resultant moment is measured by energizing external coils arranged to provide a uniform magnetic field.

Abstract: A system and method of measuring a level of settled particles in a fluid-containing vessel includes the steps of fluidizing particles from a position below the settled level of particles, and measuring a static pressure of liquid within the vessel at a position in the vessel below the settled level of particles. The fluidized static pressure is correlated to a level of settled particles within the vessel using an experimentally determined relationship. The apparatus includes an inlet pipe into the vessel at a position below the settled level of particles, and a pump which recirculates liquid from the vessel above the submerged level of particles, remote from the settled level of particles, and a static pressure instrument connected to the inlet pipe. A solids pump can be activated to remove settled particles from the vessel, the operation of the pump being controlled by the measured level of settled particles.

Abstract: A method and apparatus for determining the effectiveness and reaction time of a breaker fluid in breaking a filter cake on the wall of a wellbore penetrating a subterranean formation is disclosed. The method comprises employing an apparatus, such as for example the apparatus of the invention with a filter medium and the capability of applying differential pressure or dynamic conditions to form a filter cake on the filter medium with drilling mud. Breaker fluid is then substituted for the drilling mud, preferably without damage to the filter cake. The quantity of breaker fluid passing across the filter medium under static conditions is monitored over time. An increase in the rate of fluid passing across or through the medium indicates break-up of the filter cake.

Abstract: The invention discloses a method for counting foreign matter particles in a vinyl chloride resin powder comprising the steps of: forming an aqueous dispersion of the resin particles in a vessel having a transparent bottom, allowing the particles to settle forming a layer together with the foreign matter particles and viewing the layer of the deposited particles through the transparent bottom of the vessel to count the foreign matter particles in the deposited layer. The invention also provides an apparatus system for automatically counting foreign matter particles which comprises a vessel having a transparent bottom, a feed means for the resin powder, a water supply means, a stirrer means to form an aqueous dispersion in the vessel, a viewing means such as a CCD camera for recording the bottom image of the deposited layer through the transparent bottom of the vessel, and a control means for bringing the various parts of the system into a sequential linkage motion.