A heat flow sensor configured to provide an indication of temperature relative to a process fluid is provided. The sensor comprises a first resistance temperature detector (RTD) element and a second RTD element spaced within a sheath from the first RTD element. The sensor also includes a set of leads comprising a first subset and a second subset, wherein the first subset is coupled to the first RTD element and the second subset is coupled to the second RTD element.

There are many industrial applications where knowledge of temperature and heat flow measurements within a process is important for controlling or monitoring the process. A thermowell is a known instrument which allows measuring process fluid temperature within a vessel, such as a pipe. However, temperature sensors within thermowells may be susceptible to errors when there are differences between ambient and process temperature, particularly for thermowells.


A system for allowing a user to disable an apnea alarm in an anesthesia system when the anesthesia ventilator is in the mechanical ventilation mode. The system takes advantage of the redundancy of both a CO2 monitor and a volume monitor triggering the apnea alarm based upon a predetermined fault condition. The inventive system allows the user to disable the apnea alarm based upon a signal from the volume monitor to alleviate the problem of spurious alarm signals from the volume monitor. The attempt to disable the volume monitor fault signal to the apnea alarm is prevented, however, without a system check by a CPU to insure that the CO2 monitor is, in fact, fully operational and capable of sending its fault signal to the apnea alarm to trigger that alarm. The system continuously checks the CO2 monitor and immediately restores the viability of the volume monitor as a trigger for the apnea alarm at any time the CO2 monitor becomes disabled and is unable to trigger the apnea alarm itself. Thus the volume monitor based apnea alarm may be disabled by the user without compromising the alarm function of the overall anesthesia system.

This invention relates to medical equipment and, more particularly, to integrated anesthesia machines where a patient is induced and retained under anesthesia and where various parameters of the patient and the anesthesia machine are continuously monitored.
Anesthesia machines and/or systems are regularly used to maintain a patient undergoing surgery in a state of anesthesia and include various components, including vaporizers, to produce an anesthetic vapor from a liquid anesthetic, flowmeters and control valves for introduction of a carrier gas to carry the anesthetic to the patient and a series of monitors that carefully monitor various conditions of the patient and the status and operating condition of the anesthesia system itself.
Current anesthesia machines carry a variety of such monitors, including CO2 monitors, volume monitors, oximeters, blood pressure monitors, airway pressure monitors and the like. Many of the monitors are integrated into the anesthesia machine in order to localize all such monitors into a convenient location and to make use of the function of each of the monitors. In addition, such machines also provide a variety of alarms that are activated to alert the user as to a condition that should be investigated so as to protect the patient who, for obvious reasons, is unable to alert the attending personnel as to any such problems.
The present invention relates specifically to the alarm known as an apnea alarm and which signals an alarm condition when there is an indication that breathing has ceased or has been reduced to an unacceptable level. At present, the apnea alarm is commonly triggered based upon signals from two monitors, the CO2 monitor and the volume monitor. The CO2 monitor analyzes the level of CO2 in the patient's breathing circuit for both inspired and expired gasses and that CO2 level produces a well known wave shape during normal ventilation. The volume monitor continuously monitors the volume of gas expired by the patient and its transducer or sensor is also located in the patient breathing circuit near the patient.
As indicated, both the CO2 monitor and the volume monitor can trigger an alarm to indicate an apnea condition. Typically, the apnea alarm is triggered if the volume monitor does not indicate an increase in exhaled volume from the patient within a specific period of time, for example 30 seconds. Similarly, the CO2 monitor must receive and monitor the representative waveform within, for example, the same period of time 30 seconds. If the well known, representative waveform is not present during that period, the apnea alarm is triggered by the CO2 monitor.
As seen, therefore, the apnea alarm can be triggered by the recognition of fault conditions by either or both of the volume alarm and the CO2 alarm thereby establishing somewhat redundant systems triggering that alarm.
There is, in such anesthesia systems, a problem with spurious alarms, that is alarms that are triggered and which alert the personnel to a apnea condition wherein fact the problem is not an apnea condition and the patient is not experiencing an apnea condition. Such spurious alarms are annoying to the attending personnel since their attention is diverted to investigating the alarm condition only to find out that no alarm condition actually existed. Eventually personnel could ignore such alarms or give such alarm less than full attention on the belief that a spurious alarm was being repeated. Obviously, such a situation is not desirable.
One typical spurious alarm occurs with the apnea alarm based upon the volume monitor. A reason for the spurious apnea alarms based upon the volume monitor is that its sensor is positioned in the exhalation line of the patient circuit where the exhalation is returning from the patient to the bellows of the anesthesia machine. Often leaks occur in the exhalation flow stream and, typically, uncuffed tracheal tubes leak around the outside of such tubes such that all of the exhalation does not pass through the volume monitor sensor. The volume alarm thus interprets the lack of a predetermined volume of exhalation as a fault condition and triggers the apnea alarm even though the patent is being breathed normally.
Accordingly, it would be advantageous to be able to selectively, at the users choice, disable the apnea alarm based upon the volume monitor to prevent such spurious alarms, however, obviously, one cannot do so where the overall alarm functions of the anesthesia system would be compromised.
In present anesthesia machines, it is not therefore possible to disable or turn off the apnea alarm based upon the volume monitor when the anesthesia system is utilizing mechanical ventilation, that is where the anesthesia ventilator is breathing for the patient. If, on the other hand, the anesthesia system is in the bagging mode, that is the mechanical ventilator is not being used but instead the doctor is manually bagging the patient, it is possible to disable the apnea alarm based upon the volume monitor since in the bagging mode, it is assumed that the physician is present at the side of the patient and is visually monitoring the patients condition. As such, the alarms are not as necessary as the physician will immediately detect the apnea condition in the patient and be able to take any corrective action needed.
Accordingly, therefore, the problem of spurious apnea alarms is limited to the time in which the anesthesia ventilator is in the mechanical ventilation mode and at that time, spurious alarms are possible based upon the volume monitor.


A linear measuring instrument for attachment to a cutting saw includes a rack and pinion gear assembly for unwinding a measuring tape coiled on a rotatable drum. The pinion gears are gear coupled with the axle of the drum, and the rack gear is manually movable for rotating the pinion gears. Therefore, upon depressing the rack gear, the tape is extendable for uniformly measuring long bolts cut from a log, for example. Spaced bearings are mounted on a housing containing the drum and the tape, the bearings being in rolling engagement with the tape during the unwinding for reducing friction between the turns as the tape unwinds, and for otherwise confining the tape within the housing. A variable limit stop arrangement is provided for limiting the extent of rack gear movement and thus limiting the extent of the tape unwound from the housing so that log bolts of different uniform lengths may be cut. And, the attachment may be mounted on the cutting saw for effecting either a diagonal cut or a straight cut of the log bolts.

This invention relates to a device for uniformly measuring log bolts to be cut from a log, for example, and is adapted for attachment to a cutting saw such as a chain saw. More particularly, the device includes a rack and pinion gear assembly for unwinding the coiled tape from a drum, the pinion gears being gear coupled with the drum axle. And, rollers engage the turns of the tape during unwinding for reducing friction between the turns. Some known chain saw measuring devices include the use of rigid rods of a predetermined length, although such devices are limiting in that rods of different lengths must be substituted each time log bolts of different sizes are to be cut. Besides, these devices are cumbersome and may present a safety hazard during the handling and operation of the chain saw. Other known measuring devices include the use of a flexible tape which must be manually uncoiled and hooked onto the end of the log to be cut. It is apparent that use of such other devices is likewise cumbersome, unsafe and of limted design. A further known measuring instrument includes a measuring tape coiled on a drum, the tape being unreeled and reeled by a drive selectively coupled with the chain saw motor. Such a device, however, is not only cumbersome but is not adaptable for attachment to a conventioal chain saw.


Impact-attenuating elements include a plurality of impact-attenuating members and a means for releasably securing the impact-attenuating element to at least one of the upper member or the sole member of a piece of footwear or other foot-receiving device. The impact-attenuating elements may be included in the footwear or other foot-receiving devices in a selectively removable manner so that a user, retailer, or another can customize and freely select an appropriate element, e.g., depending on user preferences, characteristics of the user, characteristics of the intended use, and the like.

Conventional articles of athletic footwear have included two primary elements, namely, an upper member and a sole member structure. The upper member provides at least a partial covering for the foot that securely receives and positions the foot with respect to the sole structure. In addition, the upper member may have structures and a configuration that protect the foot and provide ventilation, thereby cooling the foot and removing perspiration. The sole structure generally is secured to a lower portion of the upper member and generally is positioned between the foot and the ground. In addition to attenuating ground reaction forces (i.e., imparting cushioning), the sole structure may provide traction and help control foot motions, such as pronation. Accordingly, the upper member and the sole structure operate cooperatively to provide a comfortable structure that is suited for a variety of ambulatory activities, such as walking and running.
The sole member or structure of athletic footwear generally has exhibited a layered configuration that includes a comfort-enhancing insole, a resilient midsole (e.g., formed from a polymer foam material), and a ground-contacting outsole that provides both abrasion-resistance and traction. The midsole typically is the primary sole structure element that attenuates ground reaction forces and controls foot motions. Suitable polymer foam materials for the midsole include ethylvinylacetate or polyurethane that compress resiliently under an applied load to attenuate ground reaction forces. Conventional polymer foam materials are resiliently compressible, in part, due to the inclusion of a plurality of open or closed cells that define an inner volume substantially displaced by gas.
As noted above, various ground reaction force attenuating elements and systems have been known, including such elements and systems for use in footwear products including athletic footwear products. Conventionally, the structure, feel, and characteristics of such elements and systems are selected by a footwear manufacturer, and these elements and systems (as well as their associated characteristics) are permanently fixed in the footwear products once the footwear products are made. Each individual footwear user, however, possesses unique characteristics that affect their physical fitness or training regimes, such as weight, foot size, type of workout or exercise performed, stride or gait characteristics (e.g., a pronation or supination tendency), personal tastes and preferences, etc. Therefore, this "one size fits all" approach to footwear design and production can lead to uncomfortable fits and/or limited sales due to the failure of the footwear products to match the conditions or characteristics desired and/or preferred by users.
Accordingly, it would be useful to provide footwear products or other foot-receiving devices that are readily customizable to a user's tastes and specifications, e.g., based on the user's immediate needs and/or the characteristics he/she desires in the footwear product or other foot-receiving device in general and/or at a given time.

Impact-attenuating elements removably mounted in footwear or other products


Utilization of a contact device placed on the front part of the eye in order to detect physical and chemical parameters of the body as well as the non-invasive delivery of compounds according to these physical and chemical parameters, with signals preferably being transmitted continuously as electromagnetic waves, radio waves, infrared and the like. One of the parameters to be detected includes non-invasive blood analysis utilizing chemical changes and chemical products that are found in the front part of the eye and in the tear film. A transensor mounted in the contact device laying on the cornea or the surface of the eye is capable of evaluating and measuring physical and chemical parameters in the eye including non-invasive blood analysis. The system preferably utilizes eye lid motion and/or closure of the eye lid to activate a microminiature radio frequency sensitive transensor mounted in the contact device. The signal can be communicated by cable, but is preferably actively or passively radio telemetered to an externally placed receiver. The signal can then be processed, analyzed and stored. Several parameters can be detected including a complete non-invasive analysis of blood components, measurement of systemic and ocular blood flow, measurement of heart rate and respiratory rate, tracking operations, detection of ovulation, detection of radiation and drug effects, diagnosis of ocular and systemic disorders and the like. Other advantages are somnolence awareness, activation of devices by disabled individuals, a new drug delivery system and new therapy for ocular and neurologic disorders, and treatment of cancer in the eye or other parts of the body, and an evaluation system for the overall health status of an individual. The device quantifies non-invasively the amount of the different chemical components in the blood using a contact device with suitable electrodes and membranes laying on the surface of the eye and in direct contact with the tear film or surface of the eye, with the data being preferably transmitted utilizing radio waves, but alternatively sound waves, light waves, wire, or telephone lines can be used for transmission.

The present invention relates to a tonometer system for measuring intraocular pressure by accurately providing a predetermined amount of applanation to the cornea and detecting the amount of force required to achieve the predetermined amount of applanation. The system is also capable of measuring intraocular pressure by indenting the cornea using a predetermined force applied using an indenting element and detecting the distance the indenting element moves into the cornea when the predetermined force is applied, the distance being inversely proportional to intraocular pressure. The present invention also relates to a method of using the tonometer system to measure hydrodynamic characteristics of the eye, especially outflow facility.
The tonometer system of the present invention may also be used to measure hemodynamics of the eye, especially ocular blood flow and pressure in the eye's blood vessels. Additionally, the tonometer system of the present invention may be used to increase and measure the eye pressure and evaluate, at the same time, the ocular effects of the increased pressure.
Glaucoma is a leading cause of blindness worldwide and, although it is more common in adults over age 35, it can occur at any age. Glaucoma primarily arises when intraocular pressure increases to values which the eye cannot withstand.
The fluid responsible for pressure in the eve is the aqueous humor. It is a transparent fluid produced by the eye in the ciliary body and collected and drained by a series of channels (trabecular meshwork, Schlemm's canal and venous system). The basic disorder in most glaucoma patients is caused by an obstruction or interference that restricts the flow of aqueous humor out of the eye. Such an obstruction or interference prevents the aqueous humor from leaving the eye at a normal rate. This pathologic condition occurs long before there is a consequent rise in intraocular pressure. This increased resistance to outflow of aqueous humor is the major cause of increased intraocular pressure in glaucoma-stricken patients.
Increased pressure within the eye causes progressive damage to the optic nerve. As optic nerve damage occurs, characteristic defects in the visual field develop, which can lead to blindness if the disease remains undetected and untreated. Because of the insidious nature of glaucoma and the gradual and painless loss of vision associated therewith, glaucoma does not produce symptoms that would motivate an individual to seek help until relatively late in its course when irreversible damage has already occurred. As a result, millions of glaucoma victims are unaware that they have the disease and face eventual blindness. Glaucoma can be detected and evaluated by measuring the eye's fluid pressure using a tonometer and/or by measuring the eye fluid outflow facility. Currently, the most frequently used way of measuring facility of outflow is by doing indentation tonography. According to this technique, the capacity for flow is determined by placing a tonometer upon the eye. The weight of the instrument forces aqueous humor through the filtration system, and the rate at which the pressure in the eye declines with time is related to the ease with which the fluid leaves the eye.
Individuals at risk for glaucoma and individuals who will develop glaucoma generally have a decreased outflow facility. Thus, the measurement of the outflow facility provides information which can help to identify individuals who may develop glaucoma, and consequently will allow early evaluation and institution of therapy before any significant damage occurs.
The measurement of outflow facility is helpful in making therapeutic decisions and in evaluating changes that may occur with time, aging, surgery, or the use of medications to alter intraocular pressure. The determination of outflow facility is also an important research tool for the investigation of matters such as drug effects, the mechanism of action of various treatment modalities, assessment of the adequacy of antiglaucoma therapy, detection of wide diurnal swings in pressure and to study the pathophysiology of glaucoma.
There are several methods and devices available for measuring intraocular pressure, outflow facility, and/or various other glaucoma-related characteristics of the eye. The following patents disclose various examples of such conventional devices and methods:
PATENT NO. PATENTEE 5,375,595 Sinha et al. 5,295,495 Maddess 5,251,627 Morris 5,217,015 Kaye et al. 5,183,044 Nishio et al. 5,179,953 Kursar 5,148,807 Hsu 5,109,852 Kaye et al. 5,165,409 Coan 5,076,274 Matsumoto 5,005,577 Frenkel 4,951,671 Coan 4,947,849 Takahashi et al. 4,944,303 Katsuragi 4,922,913 Waters, Jr. et al. 4,860,755 Erath 4,771,792 Seale 4,628,938 Lee 4,305,399 Beale 3,724,263 Rose et al. 3,585,849 Grolman 3,545,260 Lichtenstein et al.
Still other examples of conventional devices and/or methods are disclosed in Morey, Contact Lens Tonometer, RCA Technical Notes, No. 602, December 1964; Russell & Bergmanson, Multiple Applications of the NCT: An Assessment of the Instrument's Effect on IOP, Ophthal. Physiol. Opt., Vol. 9, April 1989, pp. 212-214; Moses & Grodzki, The Pneumatonograph: A Laboratory Study, Arch. Ophthalmol., Vol. 97, March 1979, pp. 547-552; and C. C. Collins, Miniature Passive Pressure Transensor for Implanting in the Eye, IEEE Transactions on Bio-medical Engineering, April 1967, pp. 74-83.
In general, eye pressure is measured by depressing or flattening the surface of the eye, and then estimating the amount of force necessary to produce the given flattening or depression. Conventional tonometry techniques using the principle of applanation may provide accurate measurements of intraocular pressure, but are subject to many errors in the way they are currently being performed. In addition, the present devices either require professional assistance for their use or are too complicated, expensive or inaccurate for individuals to use at home. As a result, individuals must visit an eye care professional in order to check their eye pressure. The frequent self-checking of intraocular pressure is useful not only for monitoring therapy and self-checking for patients with glaucoma, but also for the early detection of rises in pressure in individuals without glaucoma and for whom the elevated pressure was not detected during their office visit.
Pathogens that cause severe eve infection and visual impairment such as herpes and adenovirus as well as the virus that causes AIDS can be found on the surface of the eye and in the tear film. These microorganisms can be transmitted from one patient to another through the tonometer tip or probe. Probe covers have been designed in order to prevent transmission of diseases but are not widely used because they are not practical and provide less accurate measurements. Tonometers which prevent the transmission of diseases, such as the "air-puff" type of tonometer also have been designed, but they are expensive and provide less accurate measurements. Any conventional direct contact tonometers can potentially transmit a variety of systemic and ocular diseases.
The two main techniques for the measurement of intraocular pressure require a force that flattens or a force that indents the eye, called "applanation" and "indentation" tonometry respectively.
Applanation tonometry is based on the Imbert-Fick principle. This principle states that for an ideal dry, thin walled sphere, the pressure inside the sphere equals the force necessary to flatten its surface divided by the area of flattening. P=F/A (where P=pressure, F=force, A=area). In applanation tonometry, the cornea is flattened, and by measuring the applanating force and knowing the area flattened, the intraocular pressure is determined.
By contrast, according to indentation tonometry (Schiotz), a known weight (or force) is applied against the cornea and the intraocular pressure is estimated by measuring the linear displacement which results during deformation or indentation of the cornea. The linear displacement caused by the force is indicative of intraocular pressure. In particular, for standard forces and standard dimensions of the indenting device, there are known tables which correlate the linear displacement and intraocular pressure.
Conventional measurement techniques using applanation and indentation are subject to many errors. The most frequently used technique in the clinical setting is contact applanation using Goldman tonometers. The main sources of errors associated with this method include the addition of extraneous pressure on the cornea by the examiner, squeezing of the eyelids or excessive widening of the lid fissure by the patient due to the discomfort caused by the tonometer probe resting upon the eye, and inadequate or excessive amount of dye (fluorescein). In addition, the conventional techniques depend upon operator skill and require that the operator subjectively determine alignment, angle and amount of depression. Thus, variability and inconsistency associated with less valid measurements are problems encountered using the conventional methods and devices.
Another conventional technique involves air-puff tonometers wherein a puff of compressed air of a known volume and pressure is applied against the surface of the eye, while sensors detect the time necessary to achieve a predetermined amount of deformation in the eye's surface caused by application of the air puff. Such a device is described, for example, in U.S. Pat. No. 3,545,260 to Lichtenstein et al. Although the non-contact (air-puff) tonometer does not use dye and does not present problems such as extraneous pressure on the eye by the examiner or the transmission of diseases, there are other problems associated therewith. Such devices, for example, are expensive, require a supply of compressed gas, are considered cumbersome to operate, are difficult to maintain in proper alignment and depend on the skill and technique of the operator. In addition, the individual tested generally complains of pain associated with the air discharged toward the eye, and due to that discomfort many individuals are hesitant to undergo further measurement with this type of device. The primary advantage of the non-contact tonometer is its ability to measure pressure without transmitting diseases, but they are not accepted in general as providing accurate measurements and are primarily useful for large-scale glaucoma screening programs.
Tonometers which use gases, such as the pneumotonometer, have several disadvantages and limitations. Such device are also subject to the operator errors as with Goldman's tonometry. In addition, this device uses freon gas, which is not considered environmentally safe. Another problem with this device is that the gas is flammable and as with any other aerosol-type can, the can may explode if it gets too hot. The gas may also leak and is susceptible to changes in cold weather, thereby producing less accurate measurements. Transmission of diseases is also a problem with this type of device if probe covers are not utilized.
In conventional indentation tonometry (Schiotz), the main source of errors are related to the application of a relatively heavy tonometer (total weight at least 16.5 g) to the eye and the differences in the distensibility of the coats of the eye. Experience has shown that a heavy weight causes discomfort and raises the intraocular pressure. Moreover the test depends upon a cumbersome technique in which the examiner needs to gently place the tonometer onto the cornea without pressing the tonometer against the globe. The accuracy of conventional indentation may also be reduced by inadequate cleaning of the instrument as will be described later. The danger of transmitting infectious diseases, as with any contact tonometer, is also present with conventional indentation.
A variety of methods using a contact lens have been devised, however, such systems suffer from a number of restrictions and virtually none of these devices is being widely utilized or is accepted in the clinical setting due to their limitations and inaccurate readings. Moreover, such devices typically include instrumented contact lenses and/or cumbersome and complex contact lenses.
Several instruments in the prior art employ a contact lens placed in contact with the sclera (the white part of the eye). Such systems suffer from many disadvantages and drawbacks. The possibility of infection and inflammation is increased due to the presence of a foreign body in direct contact with a vascularized part of the eye. As a consequence, an inflammatory reaction around the device may occur, possibly impacting the accuracy of any measurement. In addition, the level of discomfort is high due to a long period of contact with a highly sensitive area of the eye. Furthermore, the device could slide and therefore lose proper alignment, and again, preventing accurate measurements to be taken. Moreover, the sclera is a thick and almost non-distensible coat of the eye which may further impair the ability to acquire accurate readings. Most of these devices utilize expensive sensors and complicated electric circuitry imbedded in the lens which are expensive, difficult to manufacture and sometimes cumbersome.
Other methods for sensing pressure using a contact lens on the cornea have been described. Some of the methods in this prior art also employ expensive and complicated electronic circuitry and/or transducers imbedded in the contact lens. In addition, some devices use piezoelectric material in the lens and the metalization of components of the lens overlying the optical axis decreases the visual acuity of patients using that type of device. Moreover, accuracy is decreased since the piezoelectric material is affected by small changes in temperature and the velocity with which the force is applied. There are also contact lens tonometers which utilize fluid in a chamber to cause the deformation of the cornea; however, such devices lack means for alignment and are less accurate, since the flexible elastic material is unstable and may bulge forward. In addition, the fluid therein has a tendency to accumulate in the lower portion of the chamber, thus failing to produce a stable flat surface which is necessary for an accurate measurement.
Another embodiment uses a coil wound about the inner surface of the contact lens and a magnet subjected to an externally created magnetic field. A membrane with a conductive coating is compressed against a contact completing a short circuit. The magnetic field forces the magnet against the eye and the force necessary to separate the magnet from the contact is considered proportional to the pressure. This device suffers from many limitations and drawbacks. For example, there is a lack of accuracy since the magnet will indent the cornea and when the magnet is pushed against the eye, the sclera and the coats of the eye distort easily to accommodate the displaced intraocular contents. This occurs because this method does not account for the ocular rigidity, which is related to the fact that the sclera of one person's eye is more easily stretched than the sclera of another. An eye with a low ocular rigidity will be measured and read as having a lower intraocular pressure than the actual eye's pressure. Conversely, an eye with a high ocular rigidity distends less easily than the average eye, resulting in a reading which is higher than the actual intraocular pressure. In addition, this design utilizes current in the lens which, in turn, is in direct contact with the body. Such contact is undesirable. Unnecessary cost and complexity of the design with circuits imbedded in the lens and a lack of an alignment system are also major drawbacks with this design.
Another disclosed contact lens arrangement utilizes a resonant circuit formed from a single coil and a single capacitor and a magnet which is movable relative to the resonant circuit. A further design from the same disclosure involves a transducer comprised of a pressure sensitive transistor and complex circuits in the lens which constitute the operating circuit for the transistor. All three of the disclosed embodiments are considered impractical and even unsafe for placement on a person's eye. Moreover, these contact lens tonometers are unnecessarily expensive, complex, cumbersome to use and may potentially damage the eye. In addition none of these devices permits measurement of the applanated area, and thus are generally not very practical.
The prior art also fails to provide a sufficiently accurate technique or apparatus for measuring outflow facility. Conventional techniques and devices for measuring outflow facility are limited in practice and are more likely to produce erroneous results because both are subject to operator, patient and instrument errors.
With regard to operator errors, the conventional test for outflow facility requires a long period of time during which there can be no tilting of the tonometer. The operator therefore must position and keep the weight on the cornea without moving the weight and without pressing the globe.
With regard to patient errors, if during the test the patient blinks, squeezes, moves, holds his breath, or does not maintain fixation, the test results will not be accurate. Since conventional tonography takes about four minutes to complete and generally requires placement of a relatively heavy tonometer against the eye, the chances of patients becoming anxious and therefore reacting to the mechanical weight placed on their eyes is increased.
With regard to instrument errors, after each use, the tonometer plunder and foot plate should be rinsed with water followed by alcohol and then wiped dry with lint-free material. If any foreign material drys within the foot plate, it can detrimentally affect movement of the plunger and can produce an incorrect reading.
The conventional techniques therefore are very difficult to perform and demand trained and specialized personnel. The pneumotonograph, besides having the problems associated with the pneumotonometer itself, was considered "totally unsuited to tonography." (Report by the Committee on Standardization of Tonometers of the American Academy of Ophthalmology; Archives Ophthalmol., 97:547-552, 1979). Another type of tonometer (Non Contact "Air Puff" Tonometer-U.S. Pat. No. 3,545,260) was also considered unsuitable for tonography. (Ophthalmic & Physiological Optics. 9(2):212-214, 1989). Presently there are no truly acceptable means for self-measurement of intraocular pressure and outflow facility.
In relation to an additional embodiment of the present invention, blood is responsible not only for the transport of oxygen, nutrients, glucose, cholesterol, electrolytes, water, enzymes, white and red blood cells, and genetic markers, but also provides an enormous amount of information in regards to the overall health status of an individual. The prior art related to analysis of blood relies primarily on invasive methods such as with the use of needles to draw blood for further analysis and processing. Very few and extremely limited methods for non-invasive evaluating blood components are available.
In the prior art for example, oxygenated hemoglobin has been indirectly measured by a pulse oximeter based on traditional near infrared absorption spectroscopy and indirectly measures arterial blood oxygen carried by hemoglobin (not molecular concentration of oxygen) with sensors placed over the skin utilizing LEDs emitting at two wave lengths around 940 and 660 nanometers. As the blood oxygenation changes, the ratio of the light transmitted by the two frequencies changes indicating the amount of oxygenated hemoglobin in the arterial blood of the finger tip. The present systems are not accurate and provide only the amount of oxygenated hemoglobin in the finger tip.

Apparatus for signal transmission and detection using a contact device for physical measurement on the eye


A stove for solid fuel, with sensor controlled, motor driven adjustment means for respective different types of intake air and with a control unit which is programmable for selective control of the adjustment means in order to optimise the combustion under various operational conditions, in particular during a lighting up phase, an operative phase of high or low effect, a refiring phase, and a burn-out phase.

The present invention concerns a stove for solid fuel, typically for the heating of one or more living rooms and using wood and/or briquettes as fuel. Such stoves can be configured with different shapes for more or less regulation of the air supply, whereby distinction is made between the following kinds:
A: Primary air: Air which from a lower intake opening is fed to the area down under the stove""s fire grating which supports the fuel over an underlying ash drawer, said air thus being drawn up directly through the fuel pile upon the effect of an arising or commenced combustion and related heat development in the fuel, respectively by a chimney draft established hereby with the view to strong feeding of the fire.
B: Secondary air: Air which is supplied to the pile of fuel over the fire grating, preferably after passage of a channel system in the stove for the pre-heating of this air, with the view to moderate feeding of the fire, and
C: Tertiary air: Air which is supplied to the uppermost of the combustion chamber, with the view to supplying oxygen for ensuring that remaining combustible gases are burned off, partly for maximum utilisation of the fuel by clean combustion and partly to preclude danger of explosion.
The respective air intake openings are normally provided with dampers which can be regulated manually, and which following instructions the user can operate in an appropriate manner in various operational phases of the stove, but it is also known, however, to let one or more of these dampers be controlled automatically, based on a bimetallic sensing of the combustion temperature, i.e. with the view to achieving an even combustion with the desired intensity.
However, it is also known to use an electrical servo-control of the regulation dampers for intake air, cf. EP-A-0 604 388, depending on a sensing of the temperature of the flue gas, and also depending on a measurement by means of a lambda sensor of the CO contents of the gas. No distinction is made here between different air supplies or different operational situations. When or after a stove burns out, a total closing of the regulation damper for intake air is effected, among other things to prevent flue gas explosion, and thereafter the damper is opened depending on a sensed opening of the stove door for renewed starting of the stove.
U.S. Pat. No. 4,556,044 discloses a stove with inlets for both primary and secondary air, and with a damper which can be switched over between expedient air distributions with respectively xe2x80x9chigh firexe2x80x9d, xe2x80x9cnormal combustionxe2x80x9d and xe2x80x9clow combustionxe2x80x9d. Use is made of a damper which by being switched over serves the two air intakes simultaneously.
However, it is hereby characteristic that the relevant automatic control refers precisely to the operative normal combustion in the stove, and not at all to the conditions which arise in respectively a lighting-up, a re-firing and a burning-out sequence, where the ideal air controls are quite different from the conditions during the normal combustion. It is precisely for this reason that the user should be informed how the dampers should stand during these special phases, but even with this knowledge it will be almost impossible for the user to operate the dampers in an optimum manner, when the control parameters comprise limit values for the combustion temperature and for the content of oxygen in the flue gas.
In the light of the above, with the invention there has been taken the special step of introducing an overriding, electronic and individually-directed control of the damper positions by a programmed control unit with keying-in function, which makes it possible for the user to inform the control unit that there has now been initiated a lighting-up or a re-firing phase, after which by means of sensors connected for the temperature of and possibly the oxygen content of the flue gas, the control unit will be able to control the air supplies in an optimum manner, also during the lighting-up, the re-firing and burning-out phases.
In practice, this will manifest itself by use being made of regulation dampers which in a mutually independent manner are driven by controllable step-motors, and that in connection with the stove installation there is provided an operation box which, e.g. has keying-in means in the form of pushbuttons, enables the user to key-in the time for or the event of an actual lighting-up of the oven. The same operation box can have keys for entering a desired working temperature of the stove, preferably merely for either xe2x80x9chighxe2x80x9d or xe2x80x9clow effectxe2x80x9d, and possibly have a display which confirms to the user that the oven is now operating under xe2x80x9clighting-upxe2x80x9dconditions or normal operation, or possibly in the burning-out condition, the latter as a signal to the user that the stove must be fed with new fuel if it is desirable to maintain the burning function. This information can possibly be supported by the emission of an acoustic alarm signal which, however, the user ought to be able to deactivate, e.g. if the oven with adjusted related air control is desired to burn out after bedtime. On the other hand, if the user chooses to add new fuel, the control unit can be fed with this information by a simple entry via the keypad, after which the air control undergoes a radical change for a favourable ignition of the new fuel.
The overriding control parameter will naturally be the temperature, which is best measured with a sensor placed in the flue gas discharge pipe, preferably 15-20 cm up in the flue gas discharge pipe. The user can key-in a desired combustion temperature, e.g. of 300xc2x0 or 400xc2x0, corresponding respectively to said xe2x80x9clowxe2x80x9d and xe2x80x9chighxe2x80x9d effect, and if or when it is ascertained via the sensor that the temperature is lower than the desired value, the control must then be directed in very different ways, depending on whether this is the result of a lighting-up phase or a random reduction in connection with an already-established combustion sequence. When lighting-up, there should thus be established a full air supply, while with an operative temperature reduction there should only be carried out a graduated or selective alteration of perhaps only one of the air intakes. In its way, it will be relatively easy to programme the control unit in such a manner that it can automatically detect whether the one or the other situation arises, since via the sensor it will, of course, be able to be registered whether there has previously arisen a more or less high operating temperature or whether there occurs an increase in a very low ignition temperature, and on this basis the lighting-up can possibly be registered in a fully automatic manner. However, it will give an even more sure control signal if the user indicates a lighting-up by a keying-in signal.
When lighting-up and with normal working operation, it is the said primary and secondary air supplies which are in focus, controlled only by the flue gas temperature. During the lighting-up phase, the primary air damper should be held completely open for approx. 10 minutes, also after the temperature of the flue gas has reached up to its set value of e.g. 300 or 400xc2x0, in that this damper, however, can then be controlled for a limited opening of e.g. 10-20% with the object of establishing a warming-through of the stove. After these approx. ten minutes, and after the desired operating temperature has been reached, the control unit can bring about a total closing for the flow of primary air. This applies also to operative conditions as well as with burning out.
The damper for the said secondary air must be controlled in such a way that it can not be totally closed so long as a combustion can at all take place in the stove, in that the secondary air will be responsible for the maintaining of a minimal combustion, also during a burning-out phase when the primary air is shut off, and a small intake of air will preclude the risk of explosion. During the lighting-up phase, the supply of secondary air must be fully open, while after a warming-through has been achieved, e.g. after the said 10 minutes, a change is made to actual regulation operation precisely with the help of the secondary air. If, during operation, a change is made from xe2x80x9chigh effectxe2x80x9d (400xc2x0) to xe2x80x9clow effectxe2x80x9d (300xc2x0), a down-regulation is effected, preferably so that the stove is controlled down in steps of e.g. 10xc2x0 per minute, which will provide a more or less even fall in the temperature.
In the event of xe2x80x9cfuel neededxe2x80x9d or during the start of a burning-out phase, e.g. defined by a temperature interval between 300xc2x0 and 230xc2x0, the secondary air should be fully opened for optimum utilisation of the fuel, so that this air can have as good an ignition effect as possible on the newly added fuel, while with a definite burning-out, e.g. defined by the temperature range between 230xc2x0 and 50xc2x0, there can be throttled down to an only slightly open supply of secondary air. When the stove has gone out (T less than 50xc2x0), the damper should be closed completely.
The object of the tertiary air is to ensure a clean combustion, i.e. with low emission of carbon monoxide and other combustible gases. In an indirect, but reasonably reliable and inexpensive manner, this can be monitored by using an oxygen flow-meter of the lambda probe type, in that for example it has been found that combustion is clean when, at a flue gas temperature of 400xc2x0, there appears an oxygen content in the flue gas of more than 9%, while the corresponding value at 300xc2x0 is 12%. If the oxygen content is greater or smaller, a regulation of the tertiary air must be made respectively up or down. During the lighting-up, the air supply must be at maximum, while at xe2x80x9cfuel neededxe2x80x9d or the start of a burning-out (230xc2x0 less than T less than 300xc2x0), operation can take place with a requirement control based on the information from the lambda probe. When the stove has gone out completely and with a cold stove, the supply should be closed.


There is provided a fixing device 6 including a heating body 22 which has a heating heat generation section 24 subjected to induction heating upon application of alternating magnetic fields generated by a exciting coil 27, a pressure roller 23 which has a pressing heat generation section 25 being higher in magnetic permeability than the heating heat generation section 24 and being subjected to induction heating by a part of magnetic flux in the alternating magnetic fields leaking from the heating heat generation section 24, and a drive circuit for applying drive voltage to the exciting coil, wherein a rate of the alternating magnetic fields leaking from the heating heat generation section 24 is changed by frequencies of the drive voltage.

The present invention relates to a fixing device for use in electrophotographic devices.
In electrophotographic devices, which are applied to copiers, printers, facsimiles and complex machines composed thereof, toners are fixed onto recording paper by transferring toner images on the recording paper and heating the recording paper while keeping the recording paper in between a heating body (heating roller or heating belt) and a pressing body (pressure roller or pressure belt).
In such fixing process, sufficient adhesive strength of toners to the recording paper is sometimes not achieved simply by heating a printing surface onto which toner images were transferred with a heating roller (or heating belt). Therefore, a heat source such as halogen lamps is generally placed inside each of the heating roller and the pressure roller (or heating belt).
As disclosed in JP H10-162944 A, U.S. Pat. No. 6,341,211 and JP 2003-317923 A, a technology for induction heating conducted by applying alternating magnetic fields to the heating roller is publicly known.
The induction heating requires placement of expensive exciting coils for applying alternating magnetic fields to heating elements, and placing the exciting coil in each of the heating roller and the pressure roller has imposed a heavy burden in terms of costs.
The technology disclosed in JP H10-162944 A is to provide an exciting coil extending through both a heating roller and a pressure roller so as to heat both the heating roller and the pressure roller with a single exciting coil. However, winding the exciting coil so as to alternatively go through the heating roller and the pressure roller is technically difficult to achieve and may adversely cause cost increase.
In U.S. Pat. No. 6,341,211, the frequency of a drive voltage applied to an exciting coil is controlled so as to allow downsizing of a closed magnetic circuit core, though the aspect of heating the pressure roller is not at all disclosed.
The technology disclosed in JP 2003-317923 A is to divide an exciting coil into a plurality of parts so as to constitute circuits having different resonance frequencies by resonant capacitors and to select an exciting coil to function by frequencies of drive voltages. However, this technology is to make a heating value of the heating roller appropriate and the aspect of heating the pressure roller is not at all disclosed.

Konica Minolta Business Technologies, Inc.


An ultrafast electromechanical switch having a drive mechanism comprising three non-movable contacts, an actuator, two movable contacts and a first and second mounting plate forming an elliptical shell configuration about said actuator. The switch further including a switching chamber to provide a self-contained environment that may consist of a high-pressure gas or a vacuum and one or more precision adjustment screws coupled to the non-movable contacts for adjusting the contact pressure. The provided ultrafast electrical (e.g., transfer, disconnect, etc.) switch is simple, compact, clean, exhibits ultralow loss, does not require high energy to operate and is capable of being automatically reset.

1. Field of the Invention
This invention relates, generally, to electric power systems. More specifically, it relates to mechanical switches (e.g., transfer or disconnect switches) in a hybrid circuit breaker.
2. Brief Description of the Prior Art
A transfer switch is an electrical component capable of transferring loads between multiple sources. In the past, fast transfer switches have been developed from Thomson coils, power electronics, propellant-based systems, or coupled electromechanical and hydraulic systems. However, each of the foregoing is flawed. Thomson coils require high current pulses, power electronics switches have significant conduction losses, propellant based systems cannot be automatically reset, and coupled electromechanical and hydraulic systems can be complex and slow.
For conventional disconnect switch applications where non-current-carrying electrical conductors are physically moved to achieve separation from each other, and thus creating electrical isolation, coupled mechanical systems are used to separate the contacts enough so that the voltage withstand of the contact gap is sufficient for the application. This contact separation is conventionally achieved by an indirect application of force through a series of levers, a direct application of force with the contacts enclosed in a vacuum or pressurized gas medium (called the switching chamber), or a combination of the two methods. One of the drawbacks of these methods is the fact that they are too slow and cumbersome in achieving the necessary voltage withstand capability for ultrafast medium voltage (1 kV-69 kV) switching applications. Such types of disconnect switches are not suitable for the hybrid power electronics and mechanical disconnect switch that are currently being developed around the world.
To handle high magnitude fault currents in a system, large, slow circuit breakers are typically used. However, the need to deal with these fault currents can be replaced with a need to operate as fast as possible to provide sufficient flexibility and re-configurability of the system.
Accordingly, what is needed is an ultrafast disconnect/transfer switch that is simple, compact, does not need high energy to operate (relative to the Thomson coil designs), ultralow loss (relative to the power electronic solution), clean, and capable of being automatically reset (as compared to the propellant based systems), thus providing more effective control over use and control of power. However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the field of this invention how the shortcomings of the prior art could be overcome.
While certain aspects of conventional technologies have been discussed to facilitate disclosure of the invention, Applicants in no way disclaim these technical aspects, and it is contemplated that the claimed invention may encompass one or more of the conventional technical aspects discussed herein.
The present invention may address one or more of the problems and deficiencies of the prior art discussed above. However, it is contemplated that the invention may prove useful in addressing other problems and deficiencies in a number of technical areas. Therefore, the claimed invention should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed herein.
In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge, or otherwise constitutes prior art under the applicable statutory provisions; or is known to be relevant to an attempt to solve any problem with which this specification is concerned.

This patent is subject to a terminal disclaimer.

Ultrafast electromechanical disconnect switch having elliptical shell surrounded actuator

The Florida State University Research Foundation, Inc.


Inexpensive, maintenance-free and high efficiency reluctance motors and generators have a construction that makes it possible to decrease pulsating torque and additional harmonic core loses. Each salient pole of the rotor core of the reluctance motor and generator has a shape such that the gap permeance varies in proportion to cos (N.theta..sub.2), where .theta..sub.2 represents an angular position with respect to the origin set to the center of a salient pole, or a shape analogous to the shape. In order to make up for a reduction of reluctance torque due to the shape, slits are provided inside the rotor core which cause a large reluctance for the quadrature-axis flux without interfering with the direct-axis flux.

The present invention relates to synchronous reluctance motors and generators having a simple and maintenance-free construction which can be widely used in various industrial fields. Although the present invention includes not only motors, but also generators, the following explanation will be focused on the motors, because motors are far more widely used than generators.
Reluctance motors with a simple rotor construction having no winding thereon have the merits of being maintenance-free and, moreover, have a high efficiency because no copper loss is generated in the rotor. However, reluctance motors generate pulsating torques due to the harmonic components contained in the air-gap flux, and these harmonic flux densities also produce additional core losses which reduce the efficiency.
Therefore, it is a most important problem in reluctance motors and generators in how to decrease the pulsating torques and harmonic core losses. The object of the present invention is to provide inexpensive and maintenance-free reluctance motors and generators which can be driven with high efficiency and good stability by solving the problems stated above.


A butterfly valve disk plate having a plurality of fluid directing ribs extending from the disc perpendicular to the plane of the disk, the ribs on one side of the disk being located opposite the spaces between the ribs on the other side of the disk and the ribs on one half of one side of the disk being staggered with respect to the ribs on the other half of the same side of the disk.

1. Field of the Invention
This invention relates to the design of butterfly valves and in particular to the design of the disk shaped valve plate of butterfly valves.
2. Prior Art
Prior art butterfly valves have employed disks having strengthening ribs as shown in the U.S. Pat. to Henry Masheder No. 2,986,373 issued May 30, 1961. Such strengthening ribs typically span the major portion of the face of the disk and are parallel to the direction of fluid flow. The ribs may be located on one or both sides of the disk.
It is the general objective of all butterfly valves to provide an effective valve seal assembly which results in a minimum pressure drop across the valve, requires minimum force to operate the valve and produces minimum turbulence and noise.
It is thus an object of the present invention to provide a butterfly valve which results in an improvement over prior art valves in each of the performance criteria referred to above.


An automobile sun visor has a visor body, an internal structural member arranged in the visor body and having shorter sides, a retaining clip attached to one of the shorter sides of the internal structural member and having arms provided with front edges which are flush with an outer surface of a side of the sun visor body, and a longitudinal bag-shaped sheath which covers an outer surface of the visor body and has a free end which forms a joint line on the front edges of the arms of the retaining clip.

The present invention relates to an automobile sun visor and more particularly a sun visor having a fabric and/or leather covering.
Automobile sun visors with a metallic structural member of a rectangular form and a sun visor body formed on the structural member by foamed polyurethane are very well known. The final contour of the so-formed sun visor, which is also basically rectangular, mates with the pertinent configuration of the interior of the automobile passenger compartment. These sun visors may comprise, like other visors structured in a different way, the so-called vanity mirror for the passenger side sun visor.
Sun visors are also known in general to include means for their attachment to a bracket member attached to the automobile structure, around the corresponding pivot pin of the bracket member so that the sun visor may occupy any position selected by the user among the regular positions of use. Apart from the pivot means, the sun visors also generally include a hanging bridge disposed in the end opposite to that occupied by the pivot means. The hanging bridge may engage a support member attached to the automobile structure so that, once the hanging bridge is engaged with the support member, under certain conditions they prevent the sun visor support pivot means from being subjected to mechanical overloads which could affect the operation thereof and, more precisely, the positional stability thereof.
The above described sun visors also have an external sheath like covering which consists generally of a covering of the sun visor body with a plastics material such as polypropylene. The purpose of this covering is to confer on the sun visor a surface finish in keeping with the internal finish of the automobile passenger compartment.
Where a very high quality level of the sun visor finish is requirable, the above described plastics material covering is inappropriate in view of the very notable difference of texture to be observed between the plastics material and the fabric and/or leather material used in these cases as covering for the vehicle passenger compartment.
The problems arising for providing a sunvisor of the above described type with an external covering using a woven material or leather are also known. Such problems are mainly to provide such fabric or leather covering with an external finish in which the sewn seams .of the constituent parts may not be perceived either by sight or by touch. In this respect, U.S. Pat. No. 4,822,095 discloses a sun visor having a woven material sheath and a method for the manufacture thereof. The said U.S. Pat. No. 4,822,095 describes a sun visor provided with a woven covering consisting of a sheath of essentially rectangular profile and having the perimeter closed by sewing in which the seam is completely on the inside. The interior of the sheath is accessible, for housing the sun visor body, through an opening formed for such purpose in one of the longer sides of the sheath.
The main drawbacks of the sun visor described in U.S. Pat. No. 4,822,095 are the following: the opening through which the sun visor body is inserted in the sheath is of necessity very large and, once the sun visor body is housed in the sheath, the opening must be covered or concealed with an additional member such as may be the vanity mirror itself. Also there is the need to cover or conceal the sheath opening in both sun visors normally fitted to automobiles, i.e., the driver's side sun visor and the passenger's side sun visor which, obviously, makes the production cost of the sun visors more expensive.


The atomic frequency standard has a heating element (58) surrounding an enclosure (43) which defines a microwave resonance cavity (42). The heating element supplies heat to an absorption cell (41) located in the cavity. The absorption cell (41) is surrounded by electrodes (45a-45d) which act to enhance and orient the oscillating magnetic field in the region of the absorption cell. Thermally conductive members (47a-47d) connect the electrodes (45a-45d) to the enclosure (43) to better control the temperature of the cell while retaining the advantages due to the presence of the electrodes (45a-45d).

Atomic frequency standards are devices characterised by very precise and accurate frequencies of operation, the basic resonance system of which is an atom or a molecule experiencing a transition between two well defined energy levels. The general principle of operation of frequency standards is described in the book "The Quantum Physics of Atomic Frequency Standards" by J. Vanier and C. Andion, published by Adam Hilger, Bristol and Philadelphia, 1989.
Embodiments of atomic frequency standards using a gas cell and a maser are described in Swiss Patent no. 640 370 and U.S. Pat. No. 4,316,153 respectively.
In order to illustrate the operation of a known atomic frequency standard, there will now be described an atomic frequency standard employing a gas cell having reference to FIG. 1 of the accompanying drawings.
The frequency standard shown schematically in FIG. 1 comprises essentially an atomic resonator 10, a crystal oscillator and associated frequency multiplier or synthetiser circuitry 11, and a feedback circuit 12. The atomic resonator 10 consists principally of a lamp 13, a filter cell 14, a microwave cavity 15, an absorption cell 16 and a photoelectric cell 17. A power supply 18 provides the energy necessary to drive the oscillator and associated circuitry 11, lamp 13 and control the temperature of the various components of the atomic resonator 10. A conventional heating coil 18a is supplied from and controlled by a power supply circuit 18.
Another power supply circuit 19 provides power to supply a magnetic field to the microwave cavity 15 via a coil 19a. Further, the microwave cavity 15 is surrounded by a magnetic shield 20b to block external magnetic fields from influencing the operation of the atomic resonator 10.
In the atomic frequency standard shown in FIG. 1, there is produced by optical pumping a population inversion between the hyperfine levels of the ground state of the atoms which are generally alkali metals such as potassium, sodium or rubidium. In the case of a frequency standard using rubidium, a standard optical pumping arrangement as will now be described is used.
The absorption cell 16 contains the isotope rubidium 87 the spectrum of which comprises the two hyperfine components A and B, and an appropriate buffer gas such as nitrogen. The absorption cell 16 is illuminated by the rubidium 87 lamp 13 through the filter cell 14 which contains a rubidium 85 vapour, the absorption spectrum of which contains the hyperfine components a and b. The components A and a exist practically in coincidence whilst the components B and b are completely separated. The component A of the emission spectrum of the lamp 13 is therefore essentially eliminated by the filter cell 14 so that the light which reaches the absorption cell 16 is predominantly constituted by light at the frequency of the component B. Only the atoms of the rubidium 87 of the absorption cell 16 situated in the lower hyperfine level (F=1) absorb light and are transported into higher states.
After the rubidium atoms in the absorption cell 16 have been thus excited, they relax to either the upper hyperfine level (F=2) or to the lower hyperfine level of the ground state by collisions with nitrogen molecules of the buffer gas. Since these atoms are immediately excited by the arrival of the light, the lower level (F=1) is depopulated to the benefit the upper level (F=2). Because of this asymmetry in the pumping light, there is thus brought about a population inversion of these two levels and the absorption cell 16 becomes practically transparent to residual radiation from the lamp 13.
The absorption cell 16 is arranged in the microwave cavity 15 which is excited by the circuitry 11 to a frequency close to 6835 MHz, which frequency corresponds to the separation energy of the hyperfine levels F=1, m.sub.f =0 and F=2, m.sub.f =0 which brings about the hyperfine transition accompanied by the emission of electromagnetic radiation between these two levels. As soon as the atoms which participate in the stimulated emission arrive at the lower hyperfine level (F=1), they are optically pumped and transported into the excited states.
During this process, the magnetic shield 20b reduces the ambiant external field to a low level, and a small, uniform, axial magnetic field is produced by the magnetic field coil 19a driven by the power supply circuit 19. The magnetic field thus produced in the absorption cell 16 displaces the energy values of the hyperfine levels according to the known Zeeman effect and therefore adjusts the exact frequency of the electromagnetic radiation emitted in the above described stimulated emission.
The greater the number of stimulated emissions, the greater will be quantity of light absorbed in the absorption cell 16 and the smaller will be the quantity of light arriving at the photoelectric cell 17. The current produced by the photoelectric cell 17 is therefore at a minimum when the frequency of the excitation signal of the microwave cavity 15 is at the transition frequency.
The quartz oscillator 21 of the circuitry 11 produces a signal at 5 MHz, which is modulated in a phase modulator 22 to a relatively low frequency (about 100 Hz to 1 kHz) produced by a low frequency generator 23. The modulated signal is applied to a multiplier/synthesizer 24 to obtain a signal having the stimulated emission frequency of 6835 MHz. It is this signal which is employed in order to excite the microwave cavity 15.
The signal furnished by the photoelectric cell 17 is received by an amplifier 25 of the feedback circuit 12, then applied to a phase comparator 26 which also receives a reference signal from the generator 23 of the circuitry 11 in a manner to bring about a synchronous detection enabling determination of whether the carrier frequency of the signal applied to the microwave cavity 15 is well centered on the hyperfine transition frequency (6835 MHz). Any shifting is indicated by an error signal at the output of the phase comparator 26. This signal is sent to an integrator 27, which is employed in order to control a Zener diode 28 coupled to the quartz oscillator 21 and which modifies the frequency of the latter so as to maintain the multiplied frequency of the quartz oscillator 21 centered onto the frequency of the hyperfine transition of the rubidium 87.
The stability and precision of the frequencies of operation of the atomic frequency standard of FIG. 1 depend upon the interaction of the atoms or molecules in the absorption cell 16 with the electromagnetic field in the microwave cavity 15 whilst the atoms or molecules is undergoing the above-mentioned stimulated emissions. The electromagnetic field in the microwave cavity 15 has essentially the same frequency and wave length as the atomic or molecular hyperfine transition radiation, and the physical size of the microwave cavity is related to the wave length of the radiation.
The stability and precision of the frequency of operation of the atomic resonator 10 also depend on good temperature control of the lamp 13, the absorption cell 16 and the filter cell 14. This is connected with the fact that the hyperfine transition frequency as interrogated by the multiplied frequency of the quartz oscillator 21 and detected by the light signal impinging upon the photoelectric cell 17 is influenced by the simultaneously occuring optical pumping process. The hyperfine transition frequency is slightly shifted depending on the spectrum and the intensity of the light absorbed, which is in turn a function of the temperatures of the lamp 13, filter 14 and the absorption cell 16. Furthermore, shifts in the hyperfine transition frequency due to collisions with the buffer gas are a function of the pressure and temperature of the rubidium 87 and buffer gas in the absorption cell 16.
In some prior art atomic resonators not requiring heating and/or temperature control of the atomic or molecular elements in the absorption cell, electrodes have been located circumferentially around the absorption cell within the microwave cavity in order to reduce the physical dimensions of the microwave cavity, and to intensify and orient the electromagnetic field in the region of the absorption cell within the microwave cavity. The resulting concentration of the electromagnetic field in the region of the absorption cell optimizes the filling factor and the quality factor of the microwave cavity resonator. The filling factor is the ratio of the total magnetic energy in the space occupied by the atomic or molecular elements in the absorption cell, to the total magnetic energy in the resonator; the higher the filling factor, the better the response of the atomic resonator. The quality factor is given by the ratio of the frequency of the considered resonant mode of the cavity to its resonance line-width and determined by the ratio of the energy stored to the power lost via the cavity.
The electrodes of such prior art resonators however are bonded to the absorption cell, and secured in position relative to each other by the use of a fixative such as an appropriate resin. The dielectric properties of the fixative used diminish the intensity and uniformity of the electromagnetic field in the region of the absorption cell. They are furthermore electrically and thermally insulated from the cavity walls and are designed according to design equations which rely upon this electrical and thermal separation.
Such electrodes also provide a thermal mass within the microwave cavity which makes accurate control of the temperature of the microwave cavity, and the absorption cell within, more difficult. The electrodes act to block the transfer of the heat from the walls of the microwave cavity to the interior of the cavity and to the absorption cell located thereat thereby reducing the thermal response time of the atomic resonator, and storing and subsequently radiating heat when it is desired to reduce the heating in the microwave cavity.
In prior art atomic resonators, it is further necessary to provide energy to heat not just the contents of the absorption cell where the temperature is important but also the other areas in the microwave cavity where accurate control of temperature is not required.
In addition, the fact that areas of the microwave cavity other that the absorption cell are being heated means that initially the warm-up time of the prior art atomic frequency standards is greater than desired.


A mass rate of flow meter with a first magnet and sensing coil for detecting the passage of an unrestrained rotor past the sensing coil. The position of a restrained turbine reactor is sensed by locating an axially extending magnetic flux linkage near the periphery of the turbine with an extension that is disposed in an axially overlapping relationship with a magnet that extends from the periphery of the rotor. The axial overlap produces a radial air gap that is relatively insensitive to the effects of mechanical vibration and thermal expansion.

This invention relates to mass rate of flow meters of the angular momentum type having a swirl generator for imparting swirl to the measured fluid stream and a torque balance reaction generator for removing the imparted swirl. More particularly, this invention relates to such a meter having an improved readout system for indicating the mass rate of flow.
This invention is particularly adapted for use in a mass rate of flow meter which utilizes a spring-restrained turbine as the torque balance reaction generator. One such mass rate of flow meter is depicted in U.S. Pat. No. 4,056,976 issued Nov. 8, 1977 and titled Mass Rate of Flow Meter, which patent is assigned to the same assignee as the present invention. This meter includes a housing that defines a fluid passage that extends along a longitudinal axis through the housing and that has an input port and an output port located on the axis. A swirl generator is located adjacent the input port to impart a substantially constant angular velocity to an entering fluid stream. As the fluid leaves the swirl generator, it passes through an axially displaced, unrestrained rotor that rotates about the axis. The angular velocity of the rotor accurately represents the angular velocity of the fluid stream as it leaves the rotor and passes through an axially spaced, spring-restrained turbine. The angular momentum of the fluid stream angularly displaces the turbine about the axis and against the bias of its restraining spring. Under steady state conditions, this deflection of the turbine is proportional to the mass rate of flow.
In a spring-restrained flowmeter, the rotor carries two circumferentially and longitudinally displaced bar magnets. The first magnet is disposed on the input end of the rotor and is circumferentially poled. A first sensing coil assembly in a transverse plane through the first magnet is radially spaced from the magnet and isolated from the fluid flow. Each time the first magnet passes the first sensing coil, it induces a "start" voltage pulse in the coil that indicates the passage of a predetermined point on the rotor past a predetermined point on the housing.
The second magnet is at the exit end of the rotor and diametrically opposed to the first magnet. An axially disposed, longitudinally extending bar of a highly permeable material, such as soft iron, mounts on the periphery of the turbine. The axial spacing between the rotor and the turbine interposes an axial air gap between the bar and the second magnet when they align. A second sensing coil assembly, that is isolated from the fuel flow, is coaxial with and longitudinally coextensive with the second magnet and the bar. Each time the second magnet passes the bar, the flux that the bar couples to the second sensing coil assembly changes and induces a "stop" voltage pulse in the second sensing coil. As described in the foregoing U.S. Pat. No. 4,056,976, timing circuits convert the start and stop pulses from the first and second sensing coil assemblies into an indication of the mass rate of flow through the meter.
There are, therefore, two separate, magnetic circuits in this mass rate of flow meter. The first, defined by the first magnet and the first sensing coil assembly, includes a radial air gap. The second, including the second magnet and the highly permeable bar, includes an axial air gap. During use of the mass rate of flow meter, there are several influences that tend to change the lengths of these air gaps, although to different degrees. Two such influences are vibrational forces and thermal expansion.
A typical application for such a flowmeter is in an aircraft for measuring the mass rate of flow of fuel to an engine. The engine and air frame are sources of mechanical vibrations. Also, the fuel that passes through the flow meter is subject to pressure pulsations that introduce other mechanical vibrations. These vibrations have radial and axial components that are coupled to the flowmeter and produce corresponding radial and axial forces that act on all the elements in the flowmeter. However, with the construction of the flowmeter, including the methods for mounting the rotor and turbine on a shaft for rotation, the individual elements are more stable in a radial direction than they are in an axial direction and, therefore, are less likely to vibrate in a radial direction.
In addition to vibrationally induced forces, the elements also are subjected to the forces of thermal expansion. When an aircraft is flown, the temperature of the fuel varies widely. Any elements that contact the fuel, including the rotor and the turbine of the flowmeter, are therefore subject to these temperature variations and, therefore, to thermal expansion. Both the rotor and turbine are characterized by material dimensions in the radial direction (i.e., radial thickness) that are significantly less than those in the axial direction (i.e., axial length). Thus, the radial effects of thermal expansion forces are less than the axial effects.
During operation of the flowmeter, the radial forces that are produced by vibrations and thermal expansion do not vary the length of a radial air gap sufficiently to affect the ability of the first sensing coil assembly to generate detectable pulses on a reliable basis. However, the axial forces that are produced by vibrations and thermal expansion can, in some environments, adversely affect the signal-to-noise ratio of the signal that is produced in the second sensing coil. Moreover, the problems can be increased depending upon the axial motion that is permitted by manufacturing tolerances. It is possible, under some circumstances, for the signal level from the second sensing coil assembly to reach undetectable levels and, under other circumstances, for the noise to reach a level at which it is detected as a signal. Either situation leads to erroneous flowmeter readings.

Mass rate of flow meter with improved magnetic circuit


The present invention is directed to the use of a solution of a percarbonate compound to prevent fouling during the basic washing of hydrocarbons containing oxygenated compounds. More specifically, oxygenated compounds such as carbonyl containing organics have a tendency to polymerize, producing fouling elements when such are contained in hydrocarbons being washed with basic materials. Solutions of percarbonate compounds are quite effective in reducing the fouling tendencies due to these specific mechanisms.

In cracking operations, (pyrolysis) such as in the cracking of ethane, propane and naphthas to olefins, oxygenated compounds, including carbonyl compounds, are formed. The amount of carbonyl compounds, such as aldehydes and ketones, formed in such an operation can vary widely, but is typically 1-100 ppm in the gas stream with concentrations as high as 1000 ppm occasionally being encountered. The carbonyl level is dependent on the type of feedstock used and cracking temperatures. When the gas stream is passed through a basic wash (pH>7) to remove acidic components such as hydrogen sulfide and carbon dioxide, oxygenated compounds and carbonyl compounds are also removed. These oxygen compounds, particularly acetaldehyde, will undergo polymerization in the presence of the base.
In the wash tower, the polymer will settle on the trays resulting in a loss of heat transfer efficiency, necessitating a costly shutting down of the unit in order to clean the trays. The type of basic wash systems where treatment is required to inhibit fouling include amine acid gas scrubber (e.g., MEA, DEA, isopropyl amine, butyl amine, etc.) and caustic wash systems.

Method for the prevention of fouling in a caustic solution


Disclosed is a process of removing zinc from a phosphating process sludge wherein the phosphating process sludge is mixed with an additive adapted to form slaglike compounds of iron, calcium and/or barium with the phosphorus component of the phosphating process sludges. The mixture is reacted at temperatures of at least 800.degree. C. under reducing conditions. A previous agglomeration, particularly pelletizing, of the mixture will be of advantage. For a formation of iron compounds it will be particularly desirable to employ reaction temperatures of at least 900.degree. C., preferably of at least 1000.degree. C. and most preferably of at least 1100.degree. C. Metallurgical dusts are particularly suitable additives. For a formation of iron compounds it will be desirable to select a Fe:P molar ratio of at least 1.0 in case of a reaction temperature of .ltoreq.950.degree. C., of at least 1.5 in case of a reaction temperature of 950.degree. to 1050.degree. C., and of at least 2.0 in case of a reaction temperature .gtoreq.1050.degree. C. For a formation of Ca and/or Ba compounds a molar ratio of Ca:P or Ba:P equal to or higher than 1.5 should be selected. The process can be integrated to special advantage in the waelz processing of metallurgical dusts.

The present invention is in a process of removing zinc from a zinc containing sludge formed in a phosphating process. The process of the invention is conducted at elevated temperatures and under reducing conditions in the presence of additives. The invention also includes the use of the process in the Waelz processing of metallurgical residual dusts.
Phosphating processes using zinc phosphate solutions are widely used in the metal-working industry on a large variety of metal surfaces. The phosphate layers formed on metals by that process serve particularly to facilitate sliding and non-cutting cold working, for protection against corrosion, and for improving the adherence of paint. In a phosphating process the desired conversion layer is formed on the metal surface. However, a phosphating process sludge, which must be removed periodically from the treating baths, is also formed. In a dried state, the sludge formed during the treatment of steel and iron has the following composition: 2 to 20% Zn; 10 to 30% Fe; 30 to 45% P.sub.2 O.sub.5. In the phosphating of zinc surfaces, the sludge will contain about 38 to 45% Zn. In addition to the foregoing main components, the sludge, depending on the specific phosphating bath composition, may also contain small amounts of Na, Mn, Ni, Ca, Cu, Co and other cations. The sludge may also contain small amounts of anions, such as NO.sub.3-, Cl.sup.-, and F.sup.- .
The phosphating process sludge settles in the phosphating bath and has a residual moisture content of 60 to 95%. That residual moisture content can be decreased to 30 to 50% if the sludge is squeezed out. The sludge can be dried to a moisture content of less than 10%.
The formation of sludge in the phosphating process results in disadvantages. Two major disadvantages are that the sludge binds a portion of the bath chemicals and the sludge must be disposed of as hazardous waste because of its heavy metal content. For this reason, there have been efforts to develop a process to recover the valuable substances from the sludge and to decrease the amount of waste to be disposed.
For instance, DE-A-2629776 describes a wet chemical process of treating the phosphating process sludge. That process has not yet been commercially accepted because of its economics and difficult processing technology.
U.S. Pat. No. 3,653,875 proposes treating the sludge with an alkali and reducing the solids thus obtained at 500.degree. to 1300.degree. C. to recover zinc. Trisodium phosphate can be washed out of the residue. That process also has not been commercially accepted because it is expensive as it requires a plurality of steps.
It is an object cf the invention to provide a process by which the valuable substances phosphorus and zinc contained in the phosphating process sludge are transformed into a usable form.
It is another object of the invention to provide such a process which does not result in waste waters.
It is a further object of the invention to provide a process which can be carried out in a particularly simple manner

Removal of zinc from phosphating process sludges


A binary data file embodies an inline tree data structure storing fields of a hierarchical dataset. The inline tree comprises first-level binary string segments, each comprising substantially contiguous second-level binary string segments, corresponding to subranges of first and second subsets of data fields. Size is reduced by substituting: binary string indices for alphanumeric strings; a data clump index for a set of correlated/anticorrelated strings; field masks for unoccupied data fields. A dedicated conversion program generates the inline tree from conventional database formats, which is read entirely into RAM to be searched/filtered by a dedicated search/filter program. Small size (<2 bytes/field/record) and contiguous arrangement enables searching/filtering of >106 records (>100 data fields) in <500 nanoseconds/record/core. Recursive subdivision of selection field ranges can guide searches that include those selection fields. One example includes geographic searching/filtering of records that include latitude and longitude fields.

The field of the present invention relates to electronic data search and retrieval. In particular, systems and methods are disclosed herein for high-speed searching and filtering of large datasets.
Many situations exist in which very large amounts of data are generated or collected (e.g., 104, 105, 106, or more data records, each comprising multiple data fields). For data in a dataset to be of any practical use, indicia representing the dataset are stored according to a data structure arranged so that particular pieces of information can be located and retrieved from the dataset. In the pre-digital past, such data structures often comprised printed alphanumeric indicia on suitable media (often including an accompanying printed index), and data search and retrieval were manual functions performed by humans. The introduction of electronic data storage and search capabilities around the middle of the last century revolutionized the ability to store large datasets, and to search for and retrieve specific information from those stored datasets.
Today, alphanumeric indicia representative of a dataset are typically stored according to digital, electronic data structures such as an electronic spreadsheet or an electronic relational database. A spreadsheet (also referred to as a flat file database) can be thought of as a single table with rows and columns, with each row corresponding to a specific data record, and with each column corresponding to a specific data field of that data record. In a simple example (one that will be used repeatedly within the instant specification), each data record can correspond to a registered voter in a dataset of all registered voters in a particular state, e.g., Oregon. The data fields in each data record can include, e.g., last name, first name, middle name or initial, age, gender, marital status, race, ethnicity, religion, other demographic information, street address (likely divided into multiple data fields for street number, street name, and so on), city, state, zip code, party affiliation, voting history, county, U.S. house district, state senate/house district, school district, other administrative districts, and so on.
A relational database typically comprises multiple tables, each comprising multiple records with multiple fields, and relations defined among various fields in differing tables. In the registered voter example given above, a "voter" table might include voter records with name and demographic information in corresponding fields, and an "address" table might include address records that includes street address and district information in corresponding fields. A field in the voter table can include a pointer to the corresponding address in the address table, defining a one-to-many relationship between each address and one or more corresponding voters. Other tables and relationships can be defined (including many-to-many relationships and so-called pivot tables to define them).
Electronic spreadsheets and electronic relational databases have become standard methods for storage of digital datasets. They offer nearly unlimited flexibility in arranging the data, for updating the data, for adding new data, and for sorting, searching, filtering, or retrieving data. However, it has been observed that for a very large dataset (e.g., >106 or more records, or even as few as >104 or >105 records), spreadsheets and databases tend to become unwieldy to store, access, and search. In particular, search and retrieval of information from such a large electronic dataset can become so slow as to render it essentially useless for certain data retrieval applications.
It would be desirable to provide systems and methods that enable high-speed search and retrieval of information from large electronic datasets that substantially exceed search and retrieval speeds from conventional electronic data structures (e.g., conventional spreadsheets and databases), so as to enable data search and retrieval applications that are too slow for practicable use with those conventional data structures.

Systems and methods for high-speed searching and filtering of large datasets


Authentication methods, systems and computer program products ensure that user media streaming requests originate with web documents having an authorized URL. The user makes a streaming request to a media server with a URL including a URL prefix, a path, and the name of a media work to be performed, which URL the media server compares with earlier made URL entries in a pre-established database. If there is a URL correspondence between a URL in the pre-established database and the URL extracted from the HTML document received by the browser from a web server, then streaming of the particular work is authorized.

Video or audio content presented to a user on a web browser may be in content documents and pages received from a media server, e.g., a video or audio server. The web browser may contain, or receive by downloading, a plug-in which is configured to play real-time audio or real-time video (respectively "streaming or real-time audio or video") in cooperation with streaming data from an external video or audio server. The video or audio plug-in is installed on a client machine and includes code which opens a predetermined window in the browser within which the video content is played and viewable.
Unfortunately, the content provider often has no control over the amount of content usage by a user nor over the replication of this content. Accordingly, there is a need to control content presentation and reproduction by unauthorized and unauthenticated users of media content distributed over networks, including but not limited to the Internet.
In particular, there is a desire to ensure that content is sourced from the original content producer or maker at an initial URL, rather than allowing secondary sourcing from intermediate distributors who may undesirably modify the original content, or undesirably strip off ancillary content such as advertising material for example, or who may not charge the user. Thus, it would be desirable to encourage the user to view or receive only originally constituted content.

Authentication systems, methods, and computer program products


Disclosed are various embodiments for modifying network site behavior. At least one session-level performance metric associated with a client is determined. The one or more session-level performance metrics are determined from one or more latency times. Each one of the latency times represents a time elapsed between a sending of a network page request in the client and a rendering in the client of a network page received from a network page server in response to the network page request. A response to a next network page request from the client is modified according to the one or more session-level performance metrics in order to adjust a next latency time for the client.

In recent years, broadband has quickly replaced dial-up as the primary method for accessing the Internet. One consequence of this broadband communications revolution is that Internet users have now come to expect fast performance from network sites. With a high-speed broadband network connection, a user may quickly become frustrated with a network site that is slow to load.

Modifying network site behavior using session-level performance metrics


In one aspect, the present invention is directed to dendrimers comprised of macromolecules and trifunctional branches. In another aspect, the invention relates to methods for generating dendrimeric compositions comprising macromolecules and trifunctional branches. In certain embodiments, the radial density of the dendrimeric composition is controlled by selective incorporation of branches.

Dendrimers are highly branched organic macromolecules, typically grown or generated from monomeric building blocks in a divergent, stepwise process. Upon each iterative generation, increased branching is introduced which leads to a large number of termini each containing a functional group. Ultimately, the resultant dendrimers exhibit a regular radial pattern of increasing molecular density. Ongoing challenges in the synthesis of dendrimeric molecules have been the development of a general approach to fully functionalize the termini of higher generation dendrimers, efforts to control growth of the dendrimer, the synthesis of higher generation dendrimers, and the synthesis of high molecular weight dendrimeric structures.

Heterotrifunctional molecules and methods for the synthesis of dendrimeric materials

The Trustees of Columbia University in the City of New York