A method for aiding navigation for an aircraft between a descent start point and a computation end point, comprises the computation steps of: collecting a flight plan consisting of a succession of waypoints and of the associated vertical constraints; determining a corridor consisting of a floor trajectory and of a ceiling trajectory defining the minimum and maximum altitudes permitted to the aircraft; splitting the corridor into several cells defined between two waypoints furthest apart and between which the ceiling trajectory is distinct from the floor trajectory; determining for at least one cell a vertical trajectory complying with the altitude constraints and comprising the longest possible IDLE segment; and a step consisting in determining and displaying maneuvering points of the aircraft making it possible to follow the target vertical trajectory.

Terminal procedures, covering the takeoff and landing phases, form the subject of research aimed at decreasing environmental nuisance, in particular noise or emissions of pollutant or greenhouse effect gases. The approach procedures customarily implemented generally comprise an alternating series of descent segments and of plateaus of constant altitude. Such an approach procedure is shown diagrammatically in FIG. 1 by the trajectory referenced 10. The plateaus 11 carried out at constant altitude allow the air traffic control to monitor and separate the aircraft from the relief or from other aircraft. They also make it possible to perform diverse maneuvers, such as reduce the aircraft speed or modify its aerodynamic configuration (deploy the slats, the flaps, the airbrakes) while safeguarding passenger comfort.
Alternative procedures to this plateau-based approach are envisaged. CDA procedures, the acronym standing for Continuous Descent Approach, are known for example, their aim being to descend towards the landing runway while maintaining reduced thrust so as to minimize nuisance (noise and pollution). Accordingly, it is sought to maintain the aircraft under reduced thrust, or IDLE thrust regime according to the terminology of the art, for as long as possible, between a descent start point and an exit point beyond which the reduced thrust can no longer be upheld in order to allow the aircraft to land. A CDA procedure without vertical constraint, or CDA-SCV, is represented by the trajectory 12 in FIG. 1. The aircraft is maintained under reduced thrust on this trajectory for as long as possible, and without any constant altitude plateau. A CDA procedure with vertical constraint, or CDA-PVC, is represented by the trajectory 13. In this case, the descent is also carried out under idle regime but also takes account of possible vertical constraints, in terms of altitude and/or speed at one or more intermediate points between the descent start point and the exit point.
Procedures referred to as "green" in the terminology of the art, for which the reduced-thrust descent procedures make it possible to reduce the emissions of pollutants and of greenhouse effect gases, are also known. By maintaining the idle regime for as long as possible, fuel consumption is reduced accordingly, as are airline operating costs. These reduced-thrust descent procedures and their implementations are explained in detail hereinafter.
FMS Systems of the Prior Art
Diverse systems exist for aiding a crew in the piloting of an aircraft notably during an approach phase. Known in particular among these systems are flight management systems (FMS), shown diagrammatically in FIG. 2 and comprising the following functions:                Location LOCNAV, labelled 1: making it possible to locate the aircraft by means of diverse geolocation tools or instruments (GPS, GALILEO, VHF radio beacons, inertial platforms),        Flight plan FPLN, labelled 2: making it possible to input the geographical elements constituting the skeleton of the route to be followed (departure and arrival procedures, waypoints, etc.),        Navigation database NAVDB 3: making it possible to construct geographical routes and procedures on the basis of data included in the bases (points, beacons, interception or altitude legs, etc.),        Performance database PRF DB 4: containing the craft's aerodynamic and engine parameters,        Lateral trajectory TRAJ 5: making it possible to construct a continuous trajectory on the basis of the points of the flight plan, complying with the aeroplane performance and the confinement constraints,        Predictions PRED 6: making it possible to construct an optimized vertical profile compatible with the lateral trajectory,        Guidance GUIDANCE 7: making it possible to guide the aircraft on its 3D trajectory in the lateral and vertical planes, while optimizing the speed,        Digital datalink DATALINK 8: making it possible to communicate with control centres, airlines and other aircraft.Flight Plan & Vertical Constraints
A flight plan defined by the pilot comprises a list of waypoints characterized notably by lateral and vertical geographical coordinates, speed constraints and/or transit time constraints. FIG. 3 illustrates a conventional flight plan of an aircraft 20 proceeding towards a landing runway at a landing point 21, and comprising a sequence of waypoints WPTi. On the basis of these waypoints, the FMS determines a target trajectory for the aircraft, consisting of a series of segments 22 connecting two successive waypoints. The trajectory is generally split between a lateral trajectory, determined by the TRAJ function 5, and a vertical trajectory, determined by means of the PRED function 6. In FIG. 3 is represented the lateral trajectory, referenced PP.
The constraints in terms of altitude, speed or waypoints transit time can be expressed in diverse ways. The following are known in particular:                altitude constraints, for example of the "AT" (transit the point at the given altitude), "AT OR ABOVE" (transit at or above the given altitude), "AT OR BELOW" (transit at or below the altitude) or "WINDOW" (transit between two altitudes) type,        speed constraints, for example of "AT" (transit the point at the given speed), "AT OR FASTER" (transit at or above the given speed), "AT OR LESS" (transit at or below the speed) or "WINDOW" (transit between two speeds) type, and        time constraints, for example of "AT" (transit the point at the given time), "AT OR AFTER" (transit at or after the given time), "AT OR BEFORE" (transit at or before the given time) or "WINDOW" (transit between two times) type.
Note that the speed constraints are generally defined in terms of conventional speed referred to as CAS, the acronym standing for Calibrated Air Speed. This does not constitute a limitation of the present invention which applies more generally to any type of speed constraint, for example expressed in terms of Mach number, air speed referred to as TAS the acronym standing for True Airspeed, or else in terms of ground speed referred to as GS the acronym standing for Ground Speed; all these speeds being well known to the person skilled in the art.
Other constraints exist and are not related to a given waypoint. It is possible to cite the "SPEED LIMIT" or "descent speed limit" which represents a speed not to be exceeded below a given altitude for reasons of noise and traffic sequencing in proximity to airports. For most airports around the world, this speed is 250 kts (kts=knots, i.e. about 130 m/s or 460 km/h) below 10,000 ft (ft=feet, i.e. about 3050 m). Other types of speed or altitude constraints can also exist such as constraints in terms of speed at a certain distance from the runway.
Descent and Approach Profiles
FIGS. 4a, 4b, 4c, 4d, 4e and 4f illustrate several typical descent profiles in terms of altitude and speed. For all these figures, the altitude profile is represented in the upper part of the figure, and the speed profile is represented in the lower part. The speed profile is represented in terms of conventional speed CAS. The abscissa represents the distance DtD (the acronym standing for "Distance To Destination") separating the aircraft from the landing point 21 represented on the extreme right of the figure.
Before describing these various conventional descent profiles in detail, let us recall through a few equations the principles of the vertical evolution of an aircraft in flight. The vertical evolution of a fixed-wing aircraft can be defined by the following equation of dynamics:
                              ∑                                                                              F              →                        ext                          =                  m          ·                                    ⅆ                              V                →                                                    ⅆ              t                                                          (        1        )            in which Fext represents the exterior forces applied to the aircraft, m the mass of the aircraft, and V its speed.
Under projection onto two horizontal and vertical axes, equation (1) is expressed by the following two equations:                in the horizontal plane:
                              m          ·                                    ⅆ              V                                      ⅆ              t                                      =                  Tx          -          Fx          -                                    mg              ·              sin                                                                                γ                                              (        2        )                            and in the vertical plane:Fz=mg·cos γ  (3)in which Tx is the thrust, Fx is the drag, Fz is the lift, and γ is the aerodynamic slope.
The lift can be expressed by the relation:Fz=½ρ·S·Vair2·Cz  (4)in which ρ is the density of the air, S the aerodynamic surface area, Vair the air speed and Cz the lift coefficient.
Likewise, the drag can be expressed by the relation:Fx=½ρ·S·Vair2·Cx  (5)in which Cx is the drag coefficient.
The drag and the lift of the aircraft are related by one and the same aerodynamics of the aircraft. The coefficients of lift Cz and of lift Cx are therefore related by an equation of the type:Cx=f(Cz)  (6)
The drag coefficient Cx can generally be determined in an empirical manner, by means of numerical computations or prior wind tunnel trials. This coefficient can generally be expressed by means of a relation of the type:Cx=f(Cx—smooth;Cx—conf(i) with i=1 . . . Nconf;Cx—m)  (7)in which Cx—smooth represents the drag of the aircraft in the case where the aircraft is in so-called smooth configuration, that is to say when the slats, flaps, airbrakes and landing gear are retracted; Cx—conf(i) with i=1 . . . Nconf represents the additional drag in the various possible aerodynamic situations during approach, that is to say with the slats, and/or the flaps, and/or the airbrakes and/or the landing gear deployed; and Cx—m represents the drag induced by the aircraft mass; the function "f" generally being a simple weighted sum of the various coefficients.
It is known finally that the aircraft position, lateral (x) and vertical (z), can be computed by integration as a function of the speed V and of the aerodynamic slope γ by means of the following two relations:dx/dt=V·cos γ, and dz/dt=V·sin γ  (8)
To summarize, the three variables speed V, aerodynamic slope γ and thrust Tx, are connected by two equations (the equations referenced (2) and (3)). A relationship therefore exists between these three quantities. In practice, this signifies that the piloting of the aircraft in the vertical plane can be carried out by fixing two variables, the third being deduced from the equations described hereinabove. Several modes of control in the vertical plane are thus implemented:                fixed thrust and imposed speed mode; the resultant being the slope,        fixed slope and imposed speed mode; the resultant being the thrust,        fixed slope and imposed thrust mode; the resultant being the speed,        fixed thrust and imposed acceleration/deceleration mode; the resultant being the slope.
Other modes of control, not implemented in avionics suites today, could be envisaged without departing from the scope of the present invention.
FIG. 4a represents a first conventional descent profile in terms of altitude and speed. The profile represents the target vertical trajectory of the aircraft between the descent start point and the landing runway 21. The descent start point, referenced T/D the acronym standing for Top of Descent, is characterized by a distance T/D Dist separating it from the landing point 21, an altitude CRZ ALT, and a speed CRZ MACH. In the cruising phase preceding the point T/D, the aircraft is generally in a smooth configuration.
Onwards of this point, the descent and the deceleration are carried out in several steps until the landing point 21 is reached at an altitude RWY ALT and for a landing speed VAPP.
This first descent profile comprises three successive segments:                A first segment 25 carried out at imposed speed and fixed thrust. On this segment, the descent is in general performed in two portions: a first portion on which the descent is performed at an imposed speed MACH equal to the speed DES MACH, and a second portion on which the descent is performed at an imposed speed CAS equal to DES CAS. The speed transition between the two portions is carried out at an altitude XOVER ALT for which the air speed (TAS) corresponding to DES MACH is equal to the air speed corresponding to DES CAS. Thus, the change of speed mode from MACH to CAS is performed at one and the same air speed and there is therefore no change of engine regime.
This segment 25 is in general carried out with the idle regime (IDLE). Typically, the aeroplane lets itself drop at fixed thrust while modifying its attitude (i.e. raising or lowering its nose) so as to submit itself in regard to the speed (DES MACH on the first portion, then DES CAS on the second portion). As explained above, the resultant of this fixed-thrust and imposed-speed piloting mode is the aerodynamic slope. A slightly greater slope is noted on the MACH segment. This is explained by the fact that the slope increases with the speed CAS, and that at constant MACH, the CAS increases as the altitude decreases.                A second segment 26, the aim of which is to reach a point DECEL of predetermined altitude and speed, respectively FCA ALT and SPDLIM CAS, with as constraint a speed less than or equal to SPDLIM CAS for an altitude less than an intermediate altitude SPDLIM ALT. On the basis of this dual-constraint of the arrival point DECEL and of the intermediate point, the FMS systems determine by iterative computations the point 27 onwards of which it is necessary to begin the deceleration, or stated otherwise the point of transition between the segments 25 and 26. This point 27 of change of speed is labelled by distance at SPDCHG Dist and/or by altitude at SPDCHG ALT.        A third segment 28 onwards of which the crew must begin to engage the aerodynamic approach configurations, by deploying the slats, and/or the flaps, and/or the landing gear, and/or the airbrakes. The aim of the third segment is to reach the landing point 21 from the DECEL point. A first portion 28a of the latter segment is carried out at constant altitude, making it possible to stabilize the aircraft during the phase of engaging the aerodynamic approach configurations. The approach terminates with a last portion 28b in the course of which the aircraft reaches the runway in general with imposed slope.
This cutting into three segments makes it possible to illustrate the principal steps of this descent profile, typical in aeronautics. In the known state of the art, one also speaks of "descent phase" or DES PHASE for the part preceding the DECEL point (i.e. the segments 25 and 26), and of "approach phase" or APP PHASE for the part following the DECEL point (i.e. the segment 28). The approach phase corresponds to a phase where the dynamic configuration is not smooth. The two portions of the segment 28, referenced 28a and 28b respectively, are dubbed "intermediate approach" or INT APP, and "final approach segment" or FINAL APP respectively, and correspond respectively to the portion carried out at constant altitude and to the portion carried out at constant slope.
On this first descent profile represented in FIG. 4a, the descent phase and the intermediate approach phase can be carried out in the idle regime. On the other hand, the final approach is in the computed regime, the slope and the speed being fixed. This vertical profile is very widespread and regularly implemented on commercial aircraft in the phase of descent and approach to the landing runway. This profile corresponds to the trajectory 10 of FIG. 1 described in the preamble.
FIG. 4b represents a second conventional descent profile in terms of altitude and speed. This profile exhibits numerous points in common with the first profile described in FIG. 4a which will not be repeated here in detail. The aim of this second profile is to remove the plateaus of constant altitude carried out at low altitude. Accordingly the DECEL point is shifted so as to allow an approach deceleration, between the DECEL point and the landing point 21, carried out in the idle regime (the resultant is therefore the slope). Stated otherwise, the segment 29 does not comprise any plateau. The intermediate approach segment 29a, in the course of which the aerodynamic configuration is modified, is carried out at decreasing altitude, contrary to the intermediate approach segment 28a in FIG. 4a. This second descent profile therefore corresponds to the trajectory 12 of FIG. 1 described in the preamble. This is the typical descent profile of a CDA ("Continuous Descent Approach") descent without vertical constraint. Such a descent makes it possible to limit the nuisance (sound, pollutants, etc.) in proximity to the landing runway by removing the plateaus carried out at low altitude.
FIG. 4c represents a third descent profile in terms of altitude and speed. As previously, the points in common with the profiles described in FIGS. 4a and 4b are not repeated in detail. Note that the profiles of FIGS. 4a and 4b are represented in FIG. 4c respectively by the dashed and dotted trajectories 30 and 31. This third profile comprises a vertical constraint at a point WPT6 situated between the descent start point T/D and the DECEL point. In this example, the vertical constraint is of "AT OR ABOVE" type in terms of altitude, the aircraft having to transit the point WPT6 at an altitude greater than or equal to WPT6 ALT, and of "AT OR LESS" type in terms of speed, the aircraft having to transit the point WPT6 at a speed less than or equal to WPT6 SPD. Commencing from the profiles such as described by FIGS. 4a and 4b, the descent profile is modified, for example by the addition of the following two segments:                A change-of-speed segment 32, carried out at fixed thrust and imposed acceleration/deceleration, connecting a point SPDCHG to the waypoint WPT6; the point SPDCHG being determined so as to comply with the vertical constraint at the point WPT6.        A segment 33 carried out at fixed slope and imposed speed beyond the point WPT6. The slope is bigger than that resulting from the idle regime IDLE so as to make it possible to regain the descent profile 30 at the second point SPDCHG making it possible to comply with the dual-constraint, described in FIG. 4a, of the DECEL point. This segment 33 with large slope and imposed speed makes it necessary to maintain a minimum thrust (with the idle regime IDLE) and a modification of the aerodynamic configuration (for example deployment of the airbrakes) so as to be able to maintain the speed, without which the aircraft would accelerate.
On this descent profile, the point WPT6 is therefore the point marking the end of the IDLE section, one generally speaks of "last IDLE point". The aircraft is in the smooth configuration and at fixed IDLE thrust before this point. Beyond this point, the descent becomes geometric: the aircraft is at a thrust potentially greater than the IDLE and the aerodynamic configuration may possibly be modified. The sound nuisance and the emissions of pollutants beyond this point are therefore more significant.
FIG. 4d represents a fourth descent profile in terms of altitude and speed. As previously, the profiles of FIGS. 4a and 4b are represented respectively by the dotted and dashed trajectories 30 and 31. This fourth profile comprises a vertical constraint at a point WPT5 of "AT OR BELOW" type in terms of altitude. In certain known FMS systems, this vertical constraint is taken into account by adding to the descent profile 30 such as described by FIG. 4a a segment 35 carried out onwards of the point WPT5. The segment 35 is carried out at fixed slope, a lower slope than the IDLE slope so as to regain the descent profile 30, and at imposed speed, the speed DES CAS. The resultant is a greater thrust than the IDLE reduced thrust, making it possible to maintain a constant speed up to the point SPD CHG, without which there would be deceleration.
Stated otherwise, the introduction of a vertical constraint of "AT OR BELOW" type in terms of altitude at the point WPT5 is taken into account by the FMS, by the addition of a segment making it necessary to leave the idle regime IDLE beyond this point, with here again as corollary an increase in noise and emissions of pollutants. The point WPT5 is the "last IDLE point". Faced with this type of vertical constraint, other FMS systems adapt the descent profile in a slightly different manner as described in the following figure.
FIG. 4e represents a fifth descent profile in terms of altitude and speed. Just as for FIG. 4d, this fifth profile comprises a vertical constraint at the point WPT5 of "AT OR BELOW" type in terms of altitude. In this case, the vertical constraint is taken into account by adding to the descent profile 30 such as described by FIG. 4a two successive segments 36 and 37, carried out onwards of the point WPT5. The segment 36 is carried out at constant altitude (zero fixed slope) and at imposed speed. It therefore requires a greater thrust than the IDLE reduced thrust. The following segment 37 is carried out at fixed thrust equal to the IDLE thrust and at imposed speed. This segment is carried out provided that the aircraft has reached the profile 30, that is to say provided that there has been a return to a reduced-thrust descent.
Stated otherwise, the introduction of a vertical constraint of "AT OR BELOW" type in terms of altitude at the point WPT5 is taken into account by the FMS, by the addition of a first segment with increased thrust making it possible to regain as quickly as possible a descent profile with IDLE thrust. As in the profile described by FIG. 4d, the point WPT5 is the "last IDLE point".
FIG. 4f represents a sixth descent profile in terms of altitude and speed. This profile associates the two vertical constraints introduced previously, that is to say a constraint at the point WPT5 of "AT OR BELOW" type in terms of altitude, and a constraint at the point WPT6 of "AT OR ABOVE" type in terms of altitude and "AT OR LESS" type in terms of speed. In known FMS systems, the descent profile making it possible to comply with these vertical constraints combines the segments of the descent profiles described by FIGS. 4c and 4d (or 4c and 4e). Thus, commencing from the profile 30 such as described in FIG. 4a, the modifications consist in adding:                A plateau segment 40 after the point WPT5, with zero slope and imposed speed, until the point where the descent can be continued with IDLE thrust.        A segment 41 at fixed thrust equal to the IDLE thrust, and at imposed speed. These two segments 40 and 41 make it possible to comply with the vertical constraint at the point WPT5 according to a similar strategy to that described in FIG. 4e.         A segment 42 of change of speed before the point WPT6, carried out onwards of the point SPD CHG, and for a fixed thrust and an imposed acceleration/deceleration.        A segment 43 at fixed slope and imposed speed after the point WPT6, and with a greater slope than the slope obtained in IDLE, rendered necessary for compliance with the altitude constraint at the point WPT6. Accordingly, an IDLE thrust is invoked, combined with a deployment of the airbrakes. These last two segments 42 and 43 make it possible to comply with the vertical constraint at the point WPT6 according to a similar strategy to that described in FIG. 4c.
Thus, the two vertical constraints at the points WPT5 and WPT6 have been able to be taken into account successively. To comply with each constraint, specific maneuvers are necessary. In this example, compliance with the vertical constraint at WPT5 imposes a segment 40 on which the IDLE thrust is not upheld, compliance with the constraint at WPT6 imposes a segment 43 on which the airbrakes are used. The point WPT5 is the "last IDLE point".
The typical descent profiles described by FIGS. 4a to 4f make it possible to illustrate the operating principle of the descent procedures implemented in current FMS systems. This also makes it possible to highlight the limits of known FMS systems, in particular in the case where vertical constraints must be taken into account in the descent and approach phase. Each vertical constraint being taken into account in an individual manner, the maneuvers making it possible to comply with each constraint are engaged successively without taking into account the whole set of constraints. In general, the maneuvers engaged lead to the reduced thrust mode being quit.
It is therefore desirable to have a means for computing a vertical descent trajectory capable of optimizing the CDA procedure, that is to say of maximizing the length of the segment carried out at reduced thrust and in the smooth aerodynamic configuration, between the descent start point and the point beyond which the reduced thrust cannot be upheld. It is also desirable to maximize the number and the length of the segments carried out at reduced thrust that can be integrated into the descent and approach procedure up to the landing point. Finally, it is also desirable to maximize the length of the segment carried out at reduced thrust and in the aerodynamic configuration deployed, between the start point of the approach and the runway.

Method for aiding navigation for an aircraft during descent and during approach at reduced thrust


A transmission assembly for an agricultural vehicle comprises a first transmission unit, a second transmission unit coupled to the first and a third transmission unit coupled to the second. The second transmission unit comprises an input shaft, an output shaft and two countershafts, the input shaft drives the countershafts and the countershafts drive the output shaft. The third transmission unit comprises an input shaft, which is drivingly coupled to an output shaft located in parallel thereto. The first transmission unit comprising a planetary drive and a sun gear of the first transmission unit, the input shaft and the output shaft of the second transmission unit, and the input shaft of the third transmission unit are located coaxial to each other, wherein an output of the first transmission unit is connected to the input shaft of the second transmission unit and the output shaft of the second transmission unit is connected to the input shaft of the third transmission unit.

Gear assemblies for agricultural work vehicles are known from the prior art, for example for tractors or harvesting machines, the gear assemblies having a gear system implemented by a plurality of gear units arranged in succession. Such gear assemblies are used to meet the high demands required by a gear spread which is as sensitive and as extensive as possible, as is required in agricultural work vehicles. Moreover, for the same reasons, such gear assemblies are also used in the field of construction machines.
EP 1624232 A1 discloses a gear assembly for a work vehicle comprising a plurality of gear units arranged in succession. A first gear unit is configured as a reverse gear and connected to a second gear unit. The second gear unit has an input shaft connected to a distributor stage and an output shaft. Moreover, two layshafts are provided in the second gear unit. The layshafts are driven via the distributor stage. By way of toothed wheel pairs, which are arranged by way of toothed wheels on the layshafts and the output shaft, the output shaft may be driven with different gear stages. The output shaft of the second gear unit is connected to a third gear unit. The third gear unit represents a secondary transmission and permits a further staging of the gear stages selected in the second gear unit. The disclosed gear assembly is designed to permit advantageous gear shifts at a relatively low construction cost, where there is a corresponding total gear spread. The selected design which is additionally required by the type of gear units selected, however, has only a low degree of compactness and variability, namely based on the selected construction, possibilities for variation relative to predetermined and/or selected maximum or minimum output speeds only being able to be implemented with difficulty and only with a relative high structural cost and a high number of different parts. In this regard, for example, the axial distance of at least one layshaft has to be altered, which requires further structural measures, such as the adaptation of shift forks, etc. The same applies to possibilities for increasing and adapting the power spectrum predetermined by the gear assembly, as well as possibilities for combining with additional or auxiliary drives.
A further drawback is that both the design of the gear assembly disclosed in EP 1624232 A1 and the design of other known gear assemblies of the aforementioned type, have an irregular path of the efficiency and/or power loss which is associated with high vibrations, depending on the rotational speed and/or driving speed of the respective vehicle, which is a drawback for implementing an automatic gear system, in particular when applying driving strategies with regard to optimized fuel consumption, as such paths which are irregular and/or associated with vibrations, may rapidly result in oscillation shifts. Moreover, such a gear assembly is also only suitable for use in an agricultural machine to a limited extent, such as for example in a tractor, as a power take-off shaft may only be connected indirectly to the input shaft of the gear assembly.


A method for removing an organic solute from a solution, comprising contacting the solution with a polymer formed by copolymerizing one or more hydrophobic monomers and one or more hydrophilic monomers, whereby the solute is adsorbed onto the polymer. The solution can comprise a polar solvent such as a polar organic solvent or water or an aqueous buffer. The hydrophobic monomer can be, for example, divinylbenzene. The hydrophilic monomer can be, for example, a heterocyclic monomer, such as a vinylpyridine or N-vinylpyrrolidone.

Solid phase extraction is a chromatographic technique of frequent use in the preparation of samples for quantitative analysis, for example, via high performance liquid chromatography (HPLC) or gas chromatography (GC) (McDonald and Bouvier, eds. Solid Phase Extraction Applications Guide and Bibliography, sixth edition, Milford, Mass.: Waters (1995)). Solid phase extraction can be used to separate a component of interest in a complex solution from potentially interfering matrix elements and to concentrate the analyte to levels amenable to detection and measurement. Thus, solid phase extraction is of use in the analysis of environmental samples, where, for example, various soluble components of soils may interfere with the analysis of trace organic materials. Solid phase extraction is also of importance in the analysis of pharmaceutical agents or metabolites in blood plasma, which requires the prior removal of plasma proteins and other matrix constituents which may interfere with the analysis.
Solid phase extraction of an aqueous solution is typically performed by passing the solution through a single-use cartridge containing a chromatographic sorbent. The most commonly used sorbents consist of porous silica particles that have been functionalized on their surface with hydrophobic octyl (C.sub.8) and octadecyl (C.sub.18) functional groups. Prior to use, such sorbents must be wetted with a water-miscible polar organic solvent to solvate the alkyl chains. This increases the contact of these chains with the aqueous phase, increasing the sorbent surface area available to solutes and, therefore, retention of solutes. Such sorbents which are not pre-wetted or have dried out display poor solute retention, and, thus, inadequate separation of solution components.
The requirement that the sorbent remain wetted during the extraction procedure complicates solid phase extractions and substantially slows sample analysis. For example, solid phase extraction cartridges, in general, have differing flow rates and must be monitored individually to prevent drying out when used on a vacuum manifold, the current state of the art for processing multiple samples. This further complicates the development of instruments for automated solid phase extraction, which often incorporate elaborate safeguards to prevent drying out of the sorbent.
Thus, there is need for a solid phase extraction method which utilizes a sorbent that does not require wetting with an organic solvent or that stays wetted even if the bulk of the wetting solvent is removed during use on a vacuum manifold. Such a method would enable more rapid sample preparation for quantitative analysis, particularly for multiple samples, and allow the development of less expensive and simpler methods for automated solid phase extraction.

Water-wettable chromatographic media for solid phase extraction


A prosthetic venous valve includes a frame and leaflets. The frame includes: (i) a generally hollow base disposed at a blood inflow end; (ii) a plurality of struts connected with the base and extending generally parallel to a direction of forward flow of blood from the generally hollow base to a blood outflow end; and (iii) inwardly oriented flanges disposed at the blood outflow ends of the struts. The leaflets are disposed in gaps between the struts and are supported by the frame. The leaflets are arranged to close into the vein lumen to substantially seal against backflow of blood from the blood outflow end to the blood inflow end. The inwardly oriented flanges of the struts enhance the sealing.

The following relates to the medical arts. It especially relates to prosthetic venous valves for treatment of chronic venous insufficiency, and will be described with particular reference thereto. However, the following will also find application in treatment of venous blood flow problems generally.
Chronic venous insufficiency is a pathologic condition of the skin and subcutaneous tissues of the lower extremities that results from prolonged stasis of venous blood flow. The venous stasis condition is typically brought on by an abnormal venous hypertension that upsets the normal equilibrium of capillary fluid exchange. This venous hypertension manifests pathologically as changes in the skin and subcutaneous tissues, and can lead to conditions such as edema, pigmentation, dermatitis, induration, stasis cellulitis, and stasis ulcerations. Chronic venous insufficiency is typically difficult to treat, often disabling, and negatively impacts the patient's quality of life.
The most common cause of venous hypertension is degradation of the functionality of one or more venous valves in the deep veins. These valves ordinarily function as "check valves" to prevent backflow of venous blood. However, degraded venous valves are unable to completely block backflow of venous blood, resulting in development of venous hypertension and stasis. The venous hypertension and stasis, in turn, leads to additional distention of the vein and further degradation of the valve.
Various medical therapies are used to treat chronic venous insufficiency. In the lower extremities, compression stockings or boots are used to promote flow of venous blood toward the heart. Surgical interruption of perforator veins in the regions of hypertension has been used to decrease the symptoms of chronic venous insufficiency. In some cases, the degraded venous valve can be surgically repaired.
In another approach, a vein valve is transplanted from a healthy region into the region suffering from chronic venous insufficiency. For example, venous valves in the arm can be transplanted into the leg. This approach presupposes that the patient has healthy venous valves available for transplant. Patients suffering from chronic venous insufficiency often also suffer from other vascular and/or coronary diseases, and so it may be undesirable to transplant healthy venous tissue that may be needed for later bypass procedures.
To address these concerns, both bovine and sheep vein valves have been used as substitutes for human vein valves in transplantation procedures. However, availability of suitably prepared animal vein valves, interspecies tissue compatibility, and other concerns arise in such procedures.
Attempts have also been made to replace degraded venous valves with prosthetic replacements. Existing prosthetic venous valve designs have generally been modeled on prosthetic cardiac valve designs. Prosthetic cardiac valves are normally closed, and only open in response to the substantial blood pressures generated by the beating heart. Such normally closed designs have been successful in the cardiac environment; however, they generally exhibit poor performance in the low flow, low pressure venous system that fosters thrombosis and intimal hyperplasia of implanted prosthetic devices.
Venous blood pressures are lower than those encountered in the heart, and the venous valve must remain open under low blood pressure and flow. Infrequent venous valve cycling and low venous blood pressure and flow produces substantial residency times for blood contacting the prosthetic venous valve. Flow resistance caused by a normally closed or incompletely open venous valve replacement further increases blood residency time and can lead to blood clotting.
Acosta et al., U.S. Pat. No. 6,958,076 (previously published as U.S. Publ. Appl. 2002/0177894 A1, which is incorporated herein by reference in its entirety), discloses various normally open venous valves that represent substantial improvements over previous normally closed prosthetic venous valves that are modeled after heart valves. These normally open venous valves more closely functionally mimic natural human venous valves. They provide low resistance to blood flow in the normal open condition, which reduces the residency time of blood contacting the venous valve replacement. This in turn reduces the likelihood of blood clot formation at or near the venous valve replacement.
The following contemplates improved apparatuses and methods that overcome the above-mentioned limitations and others.


It is intended to provide a filter for selectively removing leukocytes whereby leukocytes can be selectively and efficiently removed without worsening in the performance due to sterilization while causing little elution and minimizing loss in platelets. Namely, a filter for selectively removing leukocytes which is highly tolerant to sterilization and contains a polymer on the filter surface, characterized in that the polymer consists of a hydroxyalkyl (meth)acrylate unit having 3 or 4 carbon atoms in the alkyl moiety, a monomer unit having a basic nitrogen-containing functional group, and a monomer unit having an ethylene oxide chain with a repetition number of 2 to 9, the content of the monomer unit having the basic nitrogen-containing functional group ranges from 2% by mol to 9% by mol in the polymer, and the ethylene oxide chain content ranges from 1% by weight to 10% by weight in the polymer.

Currently, component transfusion in which only blood components required for a patient are transfused is more popular in the field of transfusion. In component transfusion, leukocytes must be removed from various blood products to a level low enough to prevent side effects that may occur after transfusion. As a method for removing leukocytes, a filter method is widely accepted due to advantages such as excellent leukocyte removal capability, simple operation, and low cost.
In this case, a method of removing leukocytes using a filter after separating blood into each of its components and adjusting various blood component products requires a leukocyte removal operation for each blood component product. On the other hand, a method of adjusting each blood component product after removing only leukocytes from whole blood is very useful from the viewpoint of operability and cost, since only one leukocyte removal operation is necessary.
However, since currently commercially available filters for whole blood products also remove platelets, a platelet product cannot be prepared from a whole blood product obtained by filtration using these filters. Therefore, a high performance filter that can allow platelets and erythrocytes to pass through and selectively remove leukocytes is demanded.
There are several reports on filters to remove leukocytes from blood that can allow platelets and erythrocytes to pass through. Japanese Patent Publication No. 6-51060 discloses a filter containing a nonionic hydrophilic group and a basic nitrogen-containing functional group on the surface that can be prepared by coating with a copolymer containing hydroxyethyl methacrylate (hereinafter abbreviated as HEMA) and dimethylaminoethyl methacrylate. According to research conducted by the inventors of the present invention, the filter was found to have a problem of easily allowing polymers to be eluted in spite of its capability of allowing platelets to pass through due to the high hydrophilicity of the polymer. The present inventors have found that if hydroxypropyl methacrylate, which is a little more hydrophobic than HEMA, is used instead of the HEMA, the effect of preventing elution can be achieved. However, the filter encountered a new problem of decreasing the platelet recovery rate if the filter has been sterilized with high pressure steam.
The applicants of the present invention have disclosed, in Japanese Patent Application Laid-open No. 5-194243, a leukocyte-removing filter containing an ethylene oxide chain with 2-15 ethylene oxide repetitions and a basic nitrogen-containing functional group, in which the hydrophilicity is increased and the platelet recovery rate is improved by introducing the ethylene oxide chain onto the filter surface. However, the present inventors have found that elution of a polymer into blood may be anticipated, if the ethylene oxide chain is long or the content of the ethylene oxide chain is increased.
The applicants of the present invention have further disclosed a leukocyte-removing filter containing an ethylene oxide chain with two ethylene oxide repetitions in Japanese Patent Application Laid-open No. 2000-245833. However, this filter is also thought to have a risk of elution of a polymer into the blood due to the large content of ethylene oxide chain (14-38 wt %) in the polymer used in the examples.
Moreover, the applicants of the present invention have disclosed, in Japanese Patent Application Laid-open No.7-25776, a filter for selectively removing leukocytes with a polymer having both a hydrophobic moiety and an ethylene oxide chain with 2-100 ethylene oxide repetitions coated on the surface. The filter can remove leukocytes efficiently with little platelet adhesion, while inhibiting elution of polymers. However, the filter used in the examples may also have a risk of eluting the polymer into the blood due to the large content of ethylene oxide chain (59-74 wt %) in the polymer, although the polymer has hydrophobic moieties. In view of the fact that a polymer containing an ethylene oxide chain tends to be eluted at a low temperature rather than at a high temperature, the present inventors have investigated elution of a polymer containing methyl methacrylate (30 mol %) and methoxynonaethylene glycol methacrylate (70 mol %) with 9 ethylene oxide repetitions at a normal blood processing temperature (room temperature) and have found that 20% of the polymer was eluted. In addition, although high hydrophilicity is effective for suppressing platelet adhesion, a decrease in leukocyte capturing capability is anticipated. This problem did not surface in the patent specification due to the use of a concentrated platelet solution with a low leukocyte concentration in the examples. The present inventors have found that sufficient leukocyte removal capability cannot be obtained if whole blood with an overwhelmingly high leukocyte concentration as compared with a concentrated platelet solution is used.
There have been no filters for selective removal of leukocytes having excellent sterilization resistance, high safety due to the least elution of polymers into the blood, and high blood processing performance.

Filter for selectively eliminating leukocytes


A scanning system using tree structures is constituted by a propagation operating unit array having a tree structure in which propagation units are formed into groups on each layer, and each group of the propagation operating units is connected to a propagation operating unit belonging to the higher adjacent layer, and an interface element array connected to the propagation operating units of the lowermost layer. Each of the propagation operating units is constituted by a plurality of cascaded propagation elements. Each propagation element includes first and second selectors for selecting input signals DA.sub.i and DB.sub.i from the lower adjacent layer in accordance with two propagation signals from the immediately forwarding propagation element and a third selector for selecting two propagation signals from an adjacent propagation element in accordance with an input signal U from the upper adjacent layer. The interface element includes an ALU for performing scan operating with respect to a data array consisting of part of an input scan target data array and "0", and a data array consisting of the part of the input scan target data array and "1". The interface element supplies outputs from the ALU as DA.sub.l and DB.sub.l, to the propagation operating unit of the lowermost layer of the tree-like propagation operating unit array.

1. Field of the Invention
The present invention relates to a scanning system using tree structures which is constituted by propagation operating units and designed to execute scan operations (also called associative processing, prefix processing, or propagation processing) for calculating a1, (a1 a2), (a1 a2 a3) . . . , and a1 a2 a3 . . . aM (where is an operator, called an associative operator, representing "+" , " ", " ", MIN (for obtaining a minimum value), MAX (for obtaining a maximum value), or the like) with respect to a large-scale data array of a1, a2, a3, . . . , and aM.
2. Description of the Related Art
Scan operations are of one type of basic parallel operations. By increasing the speed of these scan operations, the processing time required for various types of operations in a parallel data processing apparatus is shortened.
As a conventional method o#increasing the speed o#scan operations, a method based on processing units arranged in a binary tree structure is known, which is disclosed in, e.g., G. E. Blelloch, "Scans as Primitive Parallel Operations", Proc. Int. Conf. Parallel Process., Aug. 1987, pp. 355-362 (reference 1).
In a scanning system using tree structures according to Blelloch, processing units 1, each constituted by one (or two) arithmetic and logic unit (ALU) and an m-bit memory, are coupled to each other, forming a binary tree structure, as shown in FIG. 1(A) and (B). This system performs two types of processing: 1) sequentially performing scan operations from the lowermost layer to the uppermost layer in such a manner that predetermined associative processing is performed between two inputs supplied from the lower adjacent layer, and the processing result is output to the upper adjacent layer while an input (represented by a numerical value in a box representing a processing unit in FIG. 1(A)), supplied from a processing unit at a lower left position of the lower adjacent layer, is stored in a memory of the corresponding unit (up sweep processing) (FIG. 1(A)); and 2) sequentially performing scan operations from the uppermost layer to the lowermost layer in such a manner that an offset of the processing unit 1 located at a lower right position of the lower adjacent layer is obtained on the basis of the data obtained by the up sweep processing and stored in the memory (down sweep processing) (FIG. 1(B)). In these two types of processing, the scan processing results are output from the respective processing units 1 of the lowermost layer. As is apparent from FIGS. 1(A) and (B), since the number of layers to which the processing units 1 belong is represented by log.sub.2 M, if processing for each layer requires one step, scan operations for the overall array can be executed in 2log.sub.2 M steps required for both up sweep and down sweep. In this case, the offset of each processing unit 1 corresponds to the scan processing result obtained immediately before the scan processing region covered by the processing unit 1. Therefore, the scan processing result at a given point can be obtained by combining a corresponding offset with the local scan processing result of the corresponding processing unit 1.
In this scheme, special ALUs are arranged for up sweep and down sweep, respectively, and registers are arranged between the respective layers to realize pipeline processing, thus equivalently reducing a number of required steps to 1. However, in general processing in which scan operations are not performed repeatedly, steps of a number corresponding to a latency of 2log.sub.2 M of pipeline processing is practically required. This means that even if a number of required steps is extremely reduced as compared with the latency, the contribution of such reduction to high-speed processing is small.
For this reason, in the reference 1, Blelloch proposes a bit pipelining method (sequentially performing scan operations from the least significant digit of a scan target data array in units of bits), wherein a reduction in hardware size can be achieved, although the number of required steps increases in proportion to the word length of the scan target data array. Even this method, for example, has the following problems:
1) When a data array having a short word length, such as image data, is to be processed, the latency cannot be neglected.
2) Although the bit width of each ALU can be reduced to 1 bit, the memory capacity, of each processing unit, required to store an associative processing result cannot be reduced, resulting in an insufficient reduction in hardware size of each processing unit.
As an apparatus which can solve the problems of pipeline processing, a scanning system using tree structures is proposed by the present inventor in "Scanning Apparatus Using Tree Structures Suitable for LSI", the transactions of the Institute of Electronics, Information and Communication Engineers C-II, Vol. J74-C-II, No. 5, pp. 388-397, May 1991. This apparatus executes scan operations with a delay step count of the order of N (log.sub.N M) (capable of reducing a delay time per step to several ns or less and executing scan operations with M of several hundreds in hundred ns or less, i.e., a few clock cycles or less without performing pipeline processing). FIG. 2 shows a parallel data processing apparatus comprising a processing element (PE) array and a scanning system. In the scanning system propagation operating units for executing scan operations of the scheme described in the above literatured of the present inventor are arranged in a tree structure.
In this apparatus, the propagation operating units (POUs) 10a are coupled, forming a tree structure, and the respective units are connected to the processing element (PE) array 60.
As shown in FIG. 3, each propagation operating unit 10a is constituted by (N-1) cascaded propagation elements 30a, and has a base-N arrangement for performing scan operations for each local region (a sub array constituted by N cascaded elements of a scan target array) by performing propagation processing between the respective propagation elements 30a.
Each propagation element 30a comprises scan processing ALUs 32a and 33a, an AND gate 31 for propagation start point control, selectors (SELs) 34 and 35, and the like, as is shown in FIG. 4. Referring to FIG. 4, reference symbol FL.sub.i denotes propagation start point attribute data representing a propagation start point at which a scan region is divided into small regions; DI.sub.i, scan target data; and fd.sub.i, the offset of a scan processing result to be output to a propagation operating unit of the lower adjacent layer. The propagation start attribute data FL.sub.i and the scan processing target data DI.sub.i are input from a propagation operating unit of the lower adjacent layer or a processing element (PE) of the PE array (denoted by reference numeral 60 in FIG. 2).
Referring to FIG. 4, reference symbol CD.sub.i denotes the logical OR of propagation start point attribute data between the propagation elements 30a; and fui denotes an intermediate result of scan operations.
In addition, reference symbol DUI denotes an offset received from the propagation operating unit 10a of the upper adjacent layer.
As is apparent from the tree structure of the propagation operating units 10a and the arrangement of each propagation element 30a, each propagation operating unit 10a of the lowermost layer executes scan operations with respect to scan target data DI.sub.i of a scan processing target data array in a local region covered by each unit through the ALUs 32a and the selectors 34 of the propagation elements 30a. Results CD.sub.N and fu.sub.N are output as start point attribute data FL.sub.i and scan target data DI.sub.i with respect to a corresponding one of the propagation operating units 10a of the second lowest layer. In this case, if the start point attribute point FL.sub.i from the lower adjacent layer represents an active state ("0" in this arrangement, representing that the scan target data DI.sub.i is propagation start point data), the selector 34 is controlled to stop the propagation of the result obtained at the previous stage, and the corresponding propagation element is set as a new start point.
In the second and subsequent stages, CD.sub.N and fu.sub.N are obtained and output as the propagation start point attribute data FL.sub.i and the scan target data DI.sub.i with resect to the propagation operating unit 10a of the upper adjacent layer.
As a result, the scan operating results of the local regions are accumulated in the propagation operating unit 10a of the uppermost layer. In contrast, if "0" is supplied, as the scan target datum DUI, to the uppermost layer, a terminal fd.sub.i outputs an offset to each propagation operating unit 10a of the lower adjacent layer, as is apparent from the arrangement of the propagation element 30a constituted by the ALU 33a, the selector 35, and the AND gate 31. Since each propagation operating unit 10a of the lower adjacent layer calculates and outputs the offset of a corresponding propagation operating unit of the lower adjacent layer on the basis of the received offset, the scan operating result with respect to the data array immediately before the terminal fd.sub.i is obtained, as an offset, at the terminal fd.sub.i of each propagation operating unit of the lowermost layer.
The propagation operating units 10a of layers other than the uppermost layer are designed such that when the propagation start attribute data FL.sub.i is "0", an offset from an upper layer is neglected in the subsequently processing, and scan operations are newly started from a propagation start point.
In this arrangement, since scan operations are performed in tree-like hierarchical layers, the number of propagation elements through which the operating data pass in the scan operations is reduced to about the order of Nlog.sub.N M (where M is the array size of the scan target data array).
The number of propagation elements can be further reduced equivalently by introducing a selective propagation scheme into the propagation processing system of each propagation operating unit 10a. This scheme is disclosed in "Parallel Data Processing Apparatus" of Published Unexamined Japanese Patent Application No. 63-193232 of the present inventor. In the selective propagation scheme, propagation operations are performed for all the combinations of input signal values before an input from the forwarding stage is determined, and propagation is realized by only selecting the forwarding processing results when the input is determined. In the selective propagation scheme applied to each propagation operating unit, however, even if propagation is limited to a 1-bit signal, two combinations of an input are present, and the propagation operating paths corresponding to the number of combinations must be arranged in parallel. Therefore, the number of operating units and selectors required for scan operations is doubled as compared with a case wherein selective propagation is not utilized. In addition, the arrangement of each propagation element is complicated.
As described above, in the conventional scanning system using tree structures, when the size of a scan target data array is large, even if a pipeline structure is formed, the latency in which scan operations are performed through the propagation operating unit of the tree is long. Hence, the scan operating performance corresponding to the degree of parallel processing capability cannot be obtained. Since processing units, memories, pipeline registers, and the like must be incorporated in the respective units constituting a tree, a hardware amount as much as that of a processor section is required. In order to set a scan start point at an arbitrary position (required to perform parallel scan operations in the respective local regions of the array), a start point setting control logic must be incorporated into each propagation operating unit. The above-described problems and the like are still left unsolved.
By the way, a method of performing high-speed addition of two data by using techniques similar to the present invention is disclosed in Published Unexamined Japanese Patent Application No. 1-300337 or "Carry-Select Adder", IRE TRANSACTIONS ON ELECTRON COMPUTERS, June, pp. 340-344, which realizes high-speed processing by selecting previous processing results. The arrangement of this conventional is similar to that of the scanning system of the present invention. However, they are different from each other in the following respects:
1) In order to increase the processing speed and to decrease the hardware size, the conventional apparatus also utilizes the intrinsic characteristics of carry generation. As the result, the conventional apparatus dose not employ a regular tree structure in which each 2-input selector is controlled by an offset value as in the present invention.
2) The present invention is designed for scan operating of each bit of a large number of element data constituting a data array. By contrast, the carry-select adder is basically designed for addition of two data.
With regard to point 1), however, an adder using a tree constituted by only selectors, similar to the present invention, has been proposed, although the symmetry of the tree is slightly low. Since this adder employs a scheme for performing addition by only up sweep processing, even though it is possible to increase the processing speed, various problems are posed, e.g., low regularity of the tree and the necessity of using large sized hardware which is proportional to the square of a word length.

Nippon Telegraph and Telephone Corporation


The invention relates to a current collecting bus-bar comprising electrode housings for accommodating a multiplicity of electrodes in electrical contact therewith. Probes for measuring the electric potential locally established in correspondence of the electrical contacts during the passage of electric current are also connected to the bus-bar. The invention further relates to a permanent monitoring system allowing the continuous evaluation of current distribution on each electrode of electrolysis cells of metal electrowinning or electrorefining plants, connected to an alerting system and to means for disconnecting individual electrodes in case on non-compliance with preset values.

Current supplied to cells of electrochemical plants, with particular reference to metal electrowinning or electrorefining plants, may be apportioned to the individual cell electrodes in a very diverse and inhomogeneous way, negatively affecting the production. This kind of phenomena can take place due to a number of different reasons. For instance, in the particular case of metal electrowinning or electrorefining plants, the negatively polarised electrodes (cathodes) are frequently withdrawn from their seats in order to allow harvesting the product deposited thereon, to be put back in place later on for a subsequent production cycle. This frequent handling, which is generally carried out on a very high number of cathodes, often brings about an imperfect repositioning on the bus-bars and far from perfect electrical contacts, also due to the possible formation of scales on the relevant seats. It is also possible that product deposition take place in an irregular fashion on the electrode, with formation of product mass gradients altering the profile of cathode surfaces. When this occurs, a condition of electrical disequilibrium is established due to the anode-to-cathode gap which in fact is not constant anymore along the whole surface: the electrical resistance, which is a function of the gap between each anode-cathode pair, becomes variable worsening the problem of unevenness in current distribution.
Current can thus be apportioned to each electrode in different amounts, both due to bad electrical contacts of the electrodes themselves with the current collecting bus-bars and to the alteration of the cathode surface profile. Moreover, even the simple anode wear may affect current distribution.
These inhomogeneities in current distribution can lead to anode-cathode short-circuiting phenomena. In the event of a short-circuiting, current tends to concentrate on the short-circuited cathode subtracting current to the remaining cathodes and seriously hampering production, which cannot be restored before the short-circuited cathode is disconnected from the cell.
Furthermore, an irregular current distribution, besides provoking a loss in quality and production capacity as mentioned above, would challenge the integrity and lifetime of anodes of modern conception manufactured out of titanium meshes.
In industrial plants, given the high number of cells and electrodes that are present, the task of spotting irregularities in current distribution is a very complex one. Such a detection involves in fact thousands of manual measurements, carried out by operators by means of infrared or magnetic detectors. In the specific case of metal electrowinning or electrorefining plants, operators execute such detections in a very warm environment and in the presence of acid mists, mainly containing sulphuric acid.
Moreover, conventional manual elements used by operators, such as gaussmeters or instruments with infrared sensors, allow locating only big current distribution disequilibria, since what they really detect are unbalances associated with magnetic field or temperature variations.
These manual or semi-manual systems have the disadvantage of not working in continuous, only allowing to execute occasional checks, besides being very expensive.
There are known wireless systems for cell monitoring that, although being permanent and operating in continuous, can only detect voltage and temperature variations for each cell and not for each single electrode. For the above explained reasons, this information is scarcely accurate and globally insufficient. Moreover, there are developmental projects aiming at the continuous detection of current supplied to individual cathodes by fixed current sensors relying on Hall effect: such sensors are active components requiring a big size external power supply, for instance a large set of batteries.
Systems based on magnetic sensors are also known, however they do not offer a sufficient accuracy of measurement.
For these reasons, there exist the need by the industry of a technically and economically viable system for permanently and continuously monitoring current distribution in all electrodes installed in an electrowinning or electrorefining plant.

Permanent system for continuous detection of current distribution in interconnected electrolytic cells


A spray quantity control nozzle for use in an aerosol container wherein spray quantities of the contents of the aerosol container can be adjusted in two stages as increased or reduced corresponding to specific depression depths of a nozzle body, and a depressible depth H1 of the nozzle body for a smaller spray quantity and that H2 for a larger spray quantity can be surely set, the spray quantity control nozzle comprising a mounting part mounted on a mouth of the aerosol container and the nozzle body fit onto a projecting part of a valve stem of a flow control valve, the nozzle body being connected to the mounting part through a first molded hinge, a movable leaf being connected to the mounting part through a second molded hinge, so that a depressible depth of the nozzle body becomes smaller when the movable leaf is stood up into its working posture, and becomes larger with the movable leaf falling down in its withdrawal posture.

1. Field of the Invention
The present invention relates to a spray quantity control nozzle used for an aerosol container having a flow control valve with a function for varying aerosol flow in two stages.
An aerosol container having a flow control valve with the aforesaid function is disclosed in Japanese Examined Patent Application No. Sho 62-41074 (1987) wherein the flow control valve comprises a valve stem and has such function that a passage for the contents of the aerosol container is closed when the valve stem is positioned in an initial position and is opened when the valve stem at the initial position is depressed; and quantities of the contents flowing through the passage are restrained to be small when the valve stem is depressed into a first depression zone corresponding to a smaller depression of the valve stem from the initial position and are increased when the valve stem is depressed into a second depression zone corresponding to a larger depression of the valve stem from the initial position. Hence, when a spray nozzle mounted to the valve stem is depressed by users with a finger of their hands to cause the valve stem to be pushed into the first depression zone, spray quantities of the contents are made smaller. And when the valve stem is pushed into the second depression zone, the spray quantities are made larger.
2. Description of the Prior Art
The spray nozzle disclosed in the Japanese Publication No. Sho 62-41074 is not provided with a means for precisely defining the two stages of depression depths when the spray nozzle is pushed by the user with a finger. Thus, it is not easy for the users to determine what extent they should depress the spray nozzle to cause the spray quantities to be small or increased as required. The users of the aerosol need to manually arrange or adjust, i.e., reduce or increase, by themselves the depression depths of the spray nozzle while watching the quantities of the contents actually dispensed, so that the flow control valve's stem may be changed in depression depths from the initial position to be brought into the first or the second depression zone to cause the spray quantities to be made smaller or larger.
The manual arrangement of the nozzle's depression depths with watching the quantities of the actually dispensed contents for performing the two stage adjustment of spray quantities is not readily achievable and fails often. In detail, the spray quantities occasionally or often unnecessarily become larger contrary to the user's intention to have smaller spray quantities, or a sufficiently large quantitiy of spraying is not available when the spray quantities are to be increased. Hence, the contents of the aerosol container, for example, paint, is sprayed in an unnecessarily large quantity on a surface to be painted, or spraying on the surface is incomplete, thereby causing that surface to be not excellently finished.

Spray quantity control nozzle for aerosol container


In a transmission device connected by AC coupling, time taken before the start of transmission of valid data is shortened. The transmission device includes an internal resistor, an internal circuit, and a transmission-side control unit. One end of the internal resistor is connected to an output terminal connected to a capacitor. The internal circuit supplies one of a plurality of potentials different from each other to another end of the internal resistor. The transmission-side control unit performs control to supply one of the plurality of potentials to the internal circuit over a period from time when a potential of the output terminal is initialized to a predetermined initial value to timing when the potential of the output terminal reaches a predetermined specified value.

Conventionally, interfaces using alternating current (AC) coupling have been used for the purpose of, for example, absorbing a difference in ground between a transmission side and a reception side. Here, AC coupling is a method of connecting a transmission device and a reception device by a transmission path in which a capacitor is inserted. For example, an AC-coupled interface is proposed in which a transmission device causes transition of the potential of the transmission end from a high impedance to a fixed potential at the time of data transmission and then inputs a predetermined bit string to a driver for a certain period (for example, see Patent Document 1). In this bit string, a logical value "0" and a logical value "1" are alternately repeated, and with this bit string, the transmission device can gradually change the amplitude of an output signal of the driver to bring the amplitude to a specified value. Then, when the amplitude reaches the specified value and becomes stable, the transmission device starts transmission of valid data.

Transmission device, interface, and transmission method

SONY SEMICONDUCTOR SOLUTIONS CORPORATION


According to example embodiments, a reflective EUV mask may include a mask substrate, a patterned structure and a non-patterned structure on the mask substrate. At least one of the patterned structure and the non-patterned structure may include a thermally treated region configured to reduce a reflectivity of the respective patterned and non-patterned structure.

1. Field
Example embodiments relate to a reflective extreme ultraviolet mask and a method of manufacturing the same. More particularly, example embodiments relate to a reflective ultraviolet mask having a reflective layer, and a method of manufacturing the reflective extreme ultraviolet mask.
2. Description of the Related Art
As a design rule of a semiconductor device reduces a wavelength of a light used in an exposing process also reduces. Thus, a minute pattern may not be formed using a light such as an I-line, a G-line, a KrF, an ArF, or the like. Therefore, an extreme ultraviolet (EUV) light having a short wavelength may be used in the exposing process.
However, because the light may have high energy, most of the EUV light may be absorbed in an absorbing layer of an EUV mask, so that the EUV light may not arrive on a semiconductor substrate. To overcome this drawback, a reflective EUV mask capable of using a reflected EUV may be used.
A conventional EUV mask may include a mask substrate, a reflective layer on the mask substrate and an absorbing layer pattern on the reflective layer. An edge region of the absorbing layer pattern may correspond to a non-patterned region that may not be used in an exposing process. An EUV light reflected from a portion of the reflective layer under the edge region of the absorbing layer pattern may interfere with an EUV light reflected from a portion of the reflective layer under a patterned region of the absorbing layer pattern. Therefore, it may be required to decrease a reflectivity of the portion of the reflective layer under the edge region of the absorbing layer pattern.
In order to decrease the reflectivity of the portion of the reflective layer, the edge region of the absorbing layer pattern and the portion of the reflective layer may be removed by a plasma etching process using a photoresist pattern. Because the portion of the reflective layer may be relatively thick, the portion of the reflective layer may be removed by the several plasma etching processes.
This may cause a long time for manufacturing the reflective EUV mask. Further, because a plurality of the photoresist patterns may be used in the plasma etching processes, byproducts generated from the photoresist patterns may act as critical defects of the reflective EUV mask.
Moreover, a width of the absorbing layer pattern may determine a width of a desired pattern. A width of a portion of the absorbing layer patterns may be different from that of other absorbing layer patterns, so that a portion of the reflective layer under the portion of the absorbing layer pattern may have a reflectivity higher than that of other reflective layers. When a pattern may be formed using this abnormal reflective EUV mask, the pattern may not have a desired shape.
Furthermore, the reflectivity of the reflective layer may not be locally controlled. Thus, the abnormal reflective EUV mask may be discarded. As a result, it may be required to manufacture a new reflective EUV mask.

Reflective extreme ultraviolet mask and method of forming a pattern using the same


The invention disclosed herein relates to systems and methods for detecting, calculating, and displaying the time-of-flight or hang-time of a moving and jumping object such as a skier or snowboarder by using at least one accelerometer secured within a small wearable device. In one embodiment, the inventive device comprises: a static acceleration detection means for detecting the static acceleration of the object over at least first, second, and-third periods of time as the object respectively moves, jumps in at least first, second, and third trajectories, and lands at least first, second, and third times along the surface thereby defining at least respective first, second, and third time-of-flight events; a calculating means for determining the approximate time-of-flight of the object during the first, second, and third time-of-flight events; and a display means for displaying in a readable format the approximate time-of-flights associated with the first, second, and third time-of-flight events.

Accelerometers have found real-time applications in controlling and monitoring military and aerospace systems. For example, the basis of many modern inertial guidance systems is an arrangement that comprises three mutually perpendicular accelerometers, which can measure forces in any direction in space, coupled with three gyroscopes, also with mutually perpendicular axes, which constitute an independent frame of reference. An accelerometer measures acceleration or, more particularly, the rate at which the velocity of an object is changing. Because acceleration cannot be measured directly, an accelerometer measures the force exerted by restraints that are placed on a reference mass to hold its position fixed in an accelerating body (such as, for example, a suspended mass secured by springs within a housing). As is appreciated by those skilled in the art, acceleration is generally computed using the relationship between restraint force and acceleration given by Newton's second law: force=mass×acceleration.
The output of an accelerometer is generally in the form of a varying electrical voltage. As an object (attached to an accelerometer) accelerates, inertia causes the reference to lag behind as its housing moves ahead (accelerates with the object). The displacement of the suspended mass within its housing is proportional to the acceleration of the object. This displacement may be converted to an electrical output signal by a pointer (fixed to the mass), for example, moving over the surface of a potentiometer. Because the current supplied to the potentiometer remains constant, the movement of the pointer causes the output voltage to vary directly with the acceleration.
Specially designed accelerometers have been used in applications as varied as control of industrial vibration test equipment, detection of earthquakes (seismographs), and input to navigational an inertial guidance systems. The design differences are, primarily concerned with the method used to convert an accelerometer's output signal to an appropriate acceleration reading. In this regard an accelerometer's output may have two components: an output signal that is proportional to the force exerted by Earth's gravity at or near the surface of the earth (i.e., static acceleration), and another output signal that is proportional to the force exerted by shocks or vibrations (i.e., dynamic acceleration). Depending on the application, a signal-conditioning circuit may be required. With the advent of microelectromechanical systems (MEMS) technologies, the size and costs of accelerometers have been greatly reduced.
Recently, accelerometers have been used to detect the amount of time spent off the ground by a person during a sporting movement such as, for example, skiing, snowboarding, and biking. Exemplary in this regard are the devices disclosed in U.S. Pat. Nos. 5,636,146, 5,960,380, 6,496,787, 6,499,000, and 6,516,284. All of these closely related patent documents disclose, among other things, accelerometer-based apparatuses that are configured to sense vibrations (i.e., dynamic acceleration), particularly the vibrations experienced by a ski, snowboard, and/or bike that moves along a surface (e.g., a ski slope or mountain bike trial). In these systems, the voltage output signal from the accelerometer(s) provides a vibrational spectrum over time, and the amount of hang-time is ascertained by performing calculations on that spectrum. In particular, the vibrational spectrum sensed by these prior art devices are generally highly erratic and random, corresponding to the randomness of the surface underneath the ski, snowboard, and/or bike (as the case may be). During the period of time when the ski, snowboard, or bike is off the surface (i.e., during a "hang-time" event), however, the vibrational spectrum becomes relatively smooth because there are no longer any underlying vibrations impacting on the accelerometer(s). A microprocessor subsystem is then used to evaluate the vibrational spectrum and determine the approximate hang-tune from the duration of the relatively smooth portion sandwiched between two highly erratic and random vibrational spectrum portions. Because the condition of standing still (i.e., little or no movement) also results in a relatively smooth vibrational spectrum, these prior art devices require complicated timing methods to ensure that accurate results are displayed. In other words, the prior art devices have difficulty in accurately distinguishing between the conditions of standing still and experiencing hang-time.
Accordingly, there is still a need in the art for new and improved mechanisms for determining the time-of-flight or hang-time of a moving and jumping object such as, for example, a skier, snowboarder, skater, biker, or jumper. The present invention fulfills these needs and provides for further related advantages.

Hang timer for determining time of flight of an object


A plug for connecting to an electronic device includes a housing having an aperture, a magnetic element positioned in the aperture and having a second aperture, at least one contact within the aperture and the second aperture, a cord connected to the housing, and a mechanism configured to reduce a moment arm on the housing when a force is applied to the cord. The plug may be used as part of a connection that further includes a receptacle having a magnetic element with a recess, wherein the recess comprises an aperture, and at least one contact extending through the third aperture and into the recess.

1. Field of the Disclosure
The present disclosure generally relates to optical communication and, more particularly, to providing power and/or optical communication to an electronic device using a connector such as a plug having a magnetic connection that may be part of a connector system having a complimentary receptacle for the plug.
2. Technical Background
Conventional data and/or power connections comprise female connectors and male connectors. The male connector generally includes a cable that transmits a data signal or power, and the female connector is generally included in an electronic device. The mating of the male and female connectors provides a stable connection between the cable and the components that allows reliable data and/or power transfer across the cable and to the electronic device. Typical male and female connectors may include a mechanical interlock such as metal shells, pins or the like for securing the connection.
However, using this type of connection, damage may occur to the male connector, the female connector, and/or the electronic device in a number of ways especially in consumer applications. For example, force applied to the cable can cause the male connector and the female connector to be demated at an angle that bends the male connector and/or damages the female connector such that accurate mating is no longer possible. In another example, if force is applied to the cable and the male connector and female connector do not demate, the electronic device may be pulled so that it falls from a surface on which it was sitting, thereby causing damage to the electronic device. Moreover, consumer applications are expected to handle a relatively large number of mating cycles.
Further, electronic devices such as tablets, laptops, smart phones and the like are moving toward high-speed connections for transferring data and are considering optical transmission media in addition to, or to replace the copper transmission media. Benefits of optical fiber include extremely wide bandwidth and low noise operation. Optical cable assemblies may be utilized in consumer electronics applications to transfer data between electronic devices. However, a precise connection between optical fibers in, for example, a cable assembly and an electronic device must be provided to ensure uninterrupted transfer of data.
Accordingly, a need exists for a connector that provides a precise connection between communication media such as optical fibers in the cable and the electronic device, but that also may be demated without causing damage to the connector or the electronic device while still providing a robust and reliable connection for a relatively large number of mating cycles.

Magnetic coupling with low moment articulated plug


Provided is a hot-dip plating method that achieves good plating wettability between a metal material and a hot-dip plating bath and that makes it possible to reduce the amount of consumed energy as compared to conventional techniques. In a plating step included in the hot-dip plating method, vibration is applied to a hot-dip plating bath such that the ratio of the average sound pressure level (excluding noise) over ranges each lying between sound pressure peaks at harmonic frequencies of a fundamental frequency to the average sound pressure level (excluding noise) over the measured frequency range in an acoustic spectrum is greater than 0.2.

Methods currently used to produce hot-dip plated products (such methods are "hot-dip plating methods") are roughly categorized into continuous hot-dip plating and dip plating. The following description will discuss a hot-dip plating method for plating a steel material, which is a typical example of a metal material, by hot-dipping plating.
A continuous hot-dip plating method is a method of plating a coiled steel material (metal strip) by continuously passing (dipping and passing) the steel material through a hot-dip plating bath. A dip plating method is so-called "dip plating", which achieves plating by allowing flux to attach to a pre-molded steel material and then dipping the steel material in a hot-dip plating bath.
Equipment for use in the continuous hot-dip plating method (such equipment is referred to as "continuous hot-dip plating equipment") typically includes pre-treatment equipment, a reducing/heating furnace, a hot-dip plating bath section (molten metal pot), and post-treatment equipment. In the pre-treatment equipment, rolling oil and contaminants are removed from the steel material. In the reducing/heating furnace, a steel material is heated in an atmosphere containing H2, thereby reducing Fe oxides present at the surface of the steel material. In the hot-dip plating bath section, the steel material, which has been treated in the reducing/heating furnace, is dipped in and passed through a hot-dip plating bath while the steel material is kept in a reducing atmosphere or in an atmosphere that prevents the reoxidation of the surface of the steel material, thereby plating the steel material by hot-clip plating. In the post-treatment equipment, the hot-dip plated steel sheet is subjected to various treatments, depending on the purpose of use.
On the other hand, equipment for use in the dip plating (such equipment is referred to as "dip plating equipment") includes degreasing equipment for removing oil and contaminants from a pre-molded steel material, pickling equipment for removing Fe oxide layers (called rust or mill scale), flux equipment for allowing flux to attach to the pickled steel material, and a hot-dip plating bath section for plating the steel material by hot-dip plating after the flux is dried. In some cases, the dip plating equipment further includes post-treatment equipment similarly to the continuous hot-dip plating equipment, as necessary. The flux is used to achieve good reactivity between the steel material and the hot-dip plating bath.
Conventional hot-dip plating methods can have the following issue: plating defects (called holiday or pinhole) occur in the surface of a hot-dip plated product (half-finished product). A plating defect means an area of the surface of the steel material where the molten metal is not attached to the steel material and therefore there is no plating metal. There are various kinds of possible causes for plating defects, and measures have been taken for a long time to address this issue. For example, the following technique is proposed as one of the measures: in a continuous hot-dip plating method, after a heating treatment (reduction treatment), a metal strip is subjected to hot-dip plating while receiving ultrasonic vibration (see Patent Literatures 1 and 2). Also with regard to dip plating, the following technique is proposed: for addressing the issue that a holiday results from burnt deposit (exposure of alloy layer), dip plating is carried out using ultrasonic waves (see Patent Literature 3).
Generally, in a continuous hot-dip plating method, prior to dipping a metal strip in the molten metal pot, a treatment to anneal the material for the metal strip itself and a treatment to reduce the oxide film on the surface of the metal strip are carried out in the reducing/heating furnace. In the reducing/heating furnace, the metal strip is subjected to a heat treatment in, for example, an atmosphere containing a mixture of nitrogen and hydrogen, for reduction of the oxide film. In the heat treatment, the temperature for heating the metal strip is set according to the purpose of use of a plated product, and the metal strip is heated to at least a temperature equal to or higher than the temperature of the hot-dip plating bath for achieving good reactivity between the metal strip and the hot-dip plating bath.
Because the oxide film on the surface of the metal strip is removed via the treatments in the reducing/heating furnace, the reactivity between the metal strip and the hot-dip plating bath the hot-dip plating bath improves. This makes it possible to stably produce hot-dip plated metal strips.