The present invention encompasses a system and method for insulating an aircraft passenger cabin from ambient temperatures without the need for insulation blankets. Hot bleed air flowing through a network of fluid passageways is directed into sealed bays formed between the outer skin of the fuselage and the wall panels of the passenger cabin. As the hot bleed air rises through the sealed bays, it insulates the interior of the passenger cabin from the outside ambient temperatures. The outer skin of the aircraft acts as a heat exchanger by removing heat from the bleed air before it is introduced into the cabin. The bleed air maintains the cabin at a comfortable temperature without the need for air conditioning when the aircraft operates at high altitude.

The present invention generally relates to aircraft insulation systems employed to reduce the loss of heat from the aircraft cabin to the surrounding ambient atmosphere. More particularly, the present invention relates to a new hot bleed air distribution and insulation system which completely eliminates the need for conventional insulation blankets, thereby significantly reducing the aircraft manufacturer's material and production costs as well as the operator's corrosion repair costs.
Insulation blankets are currently employed on passenger aircraft to provide acoustic attenuation of wind noise and, more importantly, to reduce the loss of heat from the interior of an aircraft passenger cabin. A conventional insulation blanket system disclosed in U.S. Pat. No. 2,427,698 requires electrical heaters to heat and blowers to circulate heated air throughout the cabin.
At cruising altitudes achieved by today's jet aircraft, ambient temperature often drops as low as -40.degree. C., causing water vapor inside the aircraft cabin to condense onto cold metallic surfaces and become absorbed by conventional insulation blankets located in passageways extending between the passenger cabin wall panels and the outside skin of the aircraft fuselage. As a result, the weight of the insulation material can often increase the total weight of the insulation blankets by a factor of three over a three year period of time. Because wet insulation blankets have a higher thermal conductivity than dry blankets, the heat transfer rate increases, reducing the insulating effect of the blankets.
Wet insulation blankets create a number of expensive problems in the aircraft industry. The water absorbed by the insulation blankets causes corrosion of the aircraft structure. Repairing the resulting corrosion damage to the aircraft structure is very costly and may require the aircraft to be pulled from normal operation during repair. Many cases of water actually dripping into the cabin (known as "Rain in the Plane") are known to have occurred.
Insulation blankets employed in a conventional twinjet aircraft have been documented to retain an average maximum weight of 1,500 lb. and an average minimum weight of 330 lb. of water. Trijet aircraft have been documented to retain an average maximum weight of 2400 lb. and an average minimum weight of 660 lb. of water. It has been estimated that the water carried by the insulation blankets requires extra fuel costing about $14,000.00 per year per twinjet and that the water is responsible for up to five percent of the overall corrosion repair costs. While these changes in weight and resulting fuel increases may not arise with every aircraft, they are believed to be typical of the problems associated with employing insulation blankets.
In order to combat the adverse effects of water absorption by convention al insulation blankets, U.S. Pat. No. 3,740,905 suggests that insulation blankets be arranged to allow condensing moisture to drain and be collected in a central collection point. The collected water is then used to introduce humidity into the passenger compartment. As will become clear, the present invention significantly reduces the need for insulation blankets as well as a separate humidifier system.
Recognizing the need to maintain dry insulation blankets, U.S. Pat. No. 5,577,688 suggests a process and structure wherein moisture condensed within a bag of insulation material is allowed to pool under gravity, with air flowing through the enclosed space containing the bags removing the condensed liquid. While the '688 patent attempts to solve the problem by equalizing the pressure within individual insulation blankets using a source of dry air as opposed to humid cabin air, once again the corrosion and weight problems associated with insulation blankets are, at best, only somewhat reduced, and not eliminated.
Based on the above and foregoing, it can be appreciated that there presently exists a need in the art for a system and method capable of maintaining aircraft passenger cabins at comfortable temperatures while, at the same time, eliminating the problems inherent with the use of insulation blankets The successful solution must not be more costly than the current system and, if possible, should be a less expensive system to install, operate and maintain. The present invention fulfills this need in the art.

Air curtain insulating system for aircraft cabin


A lubricant is provided for use in hot working such as cross-roll rolling of a seamless steel pipe. It effectively reduces the friction coefficient between the working tools and the material under the hot work, thus extending the lives of the tools. The lubricant contains: (A) from about 10 to about 60 wt % of alkali silicate; (B) from about 1 to about 20 wt % of silane coupling agent; (C) from about 0.1 to about 5.0 wt % of at least one kind of alkali compound selected from a group consisting of an alkali hydroxide, an alkali carbonate, an alkali borate and an alkali salt of mineral acid; and (D) from about 30 to about 70 wt % of water. Alternatively, the lubricant contains: (A) from about 10 to about 60 wt % of alkali silicate; (B) from about 1 to about 20 wt % of silane coupling agent; (C) from about 0.1 to about 5.0 wt % of at least one kind of alkali compound selected from a group consisting of an alkali hydroxide, an alkali carbonate, an alkali borate and an alkali salt of mineral acid; (D) from about 5 to about 50 wt % of water; (E) from about 10 to about 60 wt % of iron oxide; and (F) from about 0.1 to about 5.0 wt % of at least one additive selected from a group consisting of a dispersant and a thickening agent.

1. Field of the Invention
The present invention relates to a lubricant adapted for use in hot work and, more particularly, to a lubricant which is suitably applied to the surfaces of hot-work tools such as a plug, guide shoe and so forth employed in a process for producing a seamless steel pipe through rolling by a cross rolling mill.
2. Description of the Related art
In general, a process for producing a seamless steel pipe in accordance with the Mannesmann method basically has the steps of: (1) piercing a round billet to form a hollow bloom; (2) elongating the hollow bloom to elongate the same; and (c) finish-rolling the tube. The steps including the piercing, elongating and finish rolling are performed with the help of tools and devices such as plugs, guide shoes, rolls and so forth.
Among these tools and devices, plugs are easily worn. Reducing the wear of the plugs is beneficial from the view point of efficiency, economy and product quality in the pipe production process. The surface of the plug is covered by a thick oxide scale which is closely adhered to the base material. The scale serves as a heat insulating layer for protecting the plug body, thus directly affecting the life of the plug. In addition, the scale reduces the rolling load and prevents deterioration. The scale alone, however, cannot provide satisfactory protective effect in many instances. Attempts have been made, therefore, to lubricate plugs used for directly piercing billets, by applying lubricants to the plugs.
For instance, Japanese Unexamined Patent Publication Nos. 51-57729 and 1-180712 disclose methods in which an oily lubricant is sprayed from the end of the plug. Japanese Unexamined Patent Publication No. 5-138213 discloses a method in which a graphite-type lubricant is applied to the plug surface before the plug is used for piercing. The first-mentioned method, however, has not yet been successfully introduced to the industry, because of difficulty encountered in forming a spray nozzle on the plug's head without impairing the shape of the plug's head which is an important factor of the plug design in the piercing process. The second-mentioned method also suffers from a disadvantage in that the graphite allows slippage of the plug. Thus, the graphite does not fully contribute to the improvement in the piercing efficiency but, rather, involves a risk of allowing problems such as failure in biting the material to be rolled and failure in the sticking of the tail end of the rolled material from the roll.
The conditions under which the plugs are used are becoming more severe, due to the current tendency towards the use of stainless steels and alloy steels to form seamless steel pipes. This is because alloy steels pose higher levels of piercing loads than ordinary steels. More specifically, when an alloy steel is used as the pipe material, the scale on the plug surface is exfoliated in a short time due to the heavy piercing load, so that the plug directly acts on the material subjected to rolling without an intermediate layer which would serve as a heat-insulating and lubricating layer, with the result that the wear of the plug is promoted.
In the production of a seamless steel pipe by a Mannesmann-type piercing mill, the pipe material is rolled and pierced by means of a pair of opposing skews or cross rolls and a plug. At the same time, a pair of guide shoes are used to prevent the outside diameter of the rolled material from increasing due to the rolling. The guide shoes may be of a stationary type or of a diskroll type.
The surfaces of the guide shoes are in such a state as to permit easy slip of the guide shoes with respect to the surface of the rolled material in the circumferential direction of the material. In addition, the guide shoes which act to prevent radial expansion of the material have to sustain a large reaction force. Consequently, the surfaces of the material tend to adhere to the guide shoes surface subjected to rolling, particularly when the material to be rolled is a high-alloy steel represented by about 13% Cr steel, about 22% Cr steel or stainless steel.
As measures for preventing such score, Japanese Unexamined Patent Publication No. 60-56406 and Japanese Examined Patent Publication No. 5-16925 disclose, respectively, methods for rolling while supplying the guide shoe surface with graphite-type lubricant and a boric acid type lubricant. In both methods, application of the lubricant to the guide shoe surface is performed by spraying.
Each of these lubricating methods, however, suffers from a problem in that flaws are liable to be generated due to insufficient anti-scoring effect when the rate of supply of the lubricant is too small. Conversely, excessive supply of the lubricant tends to cause a rolling failure due to slip between the rolled material and the rolls which undesirably reduces the friction coefficient, particularly when the lubricant is of the graphite type as disclosed in Japanese Unexamined Patent Publication No. 60-56406. When the lubricant is of the boric acid type as proposed in Japanese Examined Patent Publication No. 5-16925, the lubricant tends to be washed away by a large quantity of water such as that used for cooling, thus impairing the anti-scoring effect.
Japanese Unexamined Patent Publication No. 6-142749 discloses a method in which a billet is rolled while its surface is being supplied with a lubricant of the sodium silicate type. Japanese Unexamined Patent Publication No. 7-116709 discloses a method in which rolling is conducted while supplying the roll surface with a lubricant of swelled mica-type lubricant.
These methods, however, have the following shortcomings. The method disclosed in Japanese Unexamined Patent Publication No. 6-142749, which relies upon the application of a sodium silicate type lubricant on the billet surface during rolling, allows the exfoliation of the scale from the rolled material during transportation or rolling of the billet, as well as the separation of the lubricant from the material surface, thereby failing to provide appreciable anti-scoring effect. The method disclosed in Japanese Unexamined Patent Publication No. 7-116709, which relies upon the application of a swelled mica-type lubricant on the roll surface during rolling, is also liable to fail to satisfactorily prevent seizure because the lubricant tends to be washed away by the supply of a large quantity of water such as roll cooling water and the separation of lubricant due to exfoliation of the scale from the surface of the material subjected to the rolling.
Japanese Unexamined Patent Publication No. 5-148493 discloses the use of an aqueous solution of sodium silicate containing graphite or mica as a lubricant for lubricating a rolled material. This water-glass type lubricant, when heated, foams by allowing water content to evaporate therefrom and becomes a pumice-like substance which is then vitrified when the temperature reaches a softening point. When this type of lubricant is applied to the outer surface of the hot material to be rolled, the lubricant is softened into a glassy state so as to produce a lubricating effect upon contact with the guide shoes and rolls. This type of lubricant, by virtue of its liquid nature, can easily be applied to plugs and guide shoes which are normally held at comparatively low temperatures and, hence, seems to be suitably usable as a lubricant for such plugs and guide shoes. The inventors have found, however, that this type of lubricant cannot exhibit appreciable lubricant effect when applied to the plugs and guide shoes, for the reason that the lubricant when so used is subjected to a shearing load before it is heated up to the softening point at which it becomes glassy so that it easily comes off the surface of the plug or the guide shoe.
Japanese Unexamined Patent Publication No. 5-171165 discloses a lubricant for a material to be rolled. This lubricant has a composition composed of a particulate oxide-type laminar compound and a binder containing an alkali borate mixed with boron oxide and boric acid. Unfortunately, this lubricant does not exhibit a liquid state and, hence, cannot exhibit satisfactory adhesion or spreading by melting on the surface of a plug or guide shoes, which are usually cooled to temperatures much lower than that of the rolled material, which is usually at an elevated temperature of 900.degree. C. or higher at the internal hollow surface.
Thus, in the field of production of seamless steel pipes by the Mannesmann method, it is desirable to decrease the coefficient of friction between the material subjected to rolling and the tools such as the plug and guide shoes which are used in the step of piercing a billet and the subsequent elongating and rolling steps, thereby prolonging the lives of the plug and the guide shoes. This is particularly desirable in the cases where the billet to be processed is made of a material which imposes a heavy load on the rolling tool and other devices, such as a stainless steel or an alloy steel, is used as the material of the billet.


An fMRI scan is performed using a multi-element head coil and multi-channel receiver to acquire time course image data. One imaging gradient is eliminated from the pulse sequence used to acquire the time course image data enabling images to be acquired at a very high frame rate. The multi-channel NMR data is combined and reconstructed into a series of image frames using an imaging inversion operator.

The field of the invention is nuclear magnetic resonance imaging (MRI) methods and systems. More particularly, the invention relates to dynamic studies in which a series of MR images are acquired at a high temporal resolution.
When a substance such as human tissue is subjected to a uniform magnetic field (polarizing field B0), the individual magnetic moments of the spins in the tissue attempt to align with this polarizing field, but precess about it in random order at their characteristic Larmor frequency. If the substance, or tissue, is subjected to a magnetic field (excitation field B1) which is in the x-y plane and which is near the Larmor frequency, the net aligned moment, Mz, may be rotated, or "tipped", into the x-y plane to produce a net transverse magnetization. A NMR signal is emitted by the excited spins after the excitation signal B1 is terminated, and this NMR signal may be received and processed to form an image.
When utilizing these signals to produce images, magnetic field gradients (Gx, Gy and Gz) are employed. Typically, the region to be imaged is scanned, or sampled, by a sequence of measurement cycles in which these gradients vary according to the particular localization method being used. The resulting set of received NMR signals are digitized and processed to reconstruct the image using one of many well known reconstruction techniques.
There are many methods used to sample 2D or 3D "k-space" during an MRI scan. The most common method in use today is the Fourier transform (FT) imaging technique, which is frequently referred to as "spin-warp". The spin-warp technique is discussed in an article entitled "Spin-Warp NMR Imaging and Applications to Human Whole-Body Imaging" by W. A. Edelstein et al., Physics in Medicine and Biology, Vol. 25, pp. 751-756 (1980). It employs a variable amplitude phase encoding magnetic field gradient pulse prior to the acquisition of NMR echo signals to phase encode spatial information in the direction of this gradient. In a two-dimensional implementation (2DFT), for example, spatial information is encoded in one direction by applying a phase encoding gradient (Gy) along that direction, and then an NMR echo signal is acquired in the presence of a readout magnetic field gradient (Gx) in a direction orthogonal to the phase encoding direction. The readout gradient present during the spin-echo acquisition encodes spatial information in the orthogonal direction. In a typical 2DFT pulse sequence, the magnitude of the phase encoding gradient pulse Gy is incremented (ΔGy) in the sequence of views that are acquired during the scan to produce a set of NMR data from which an entire image can be reconstructed. A 3DFT scan is similar except a second phase encoding gradient directed along the third axis is also stepped through a set of values.
To reduce the time needed to acquire data for an MR image multiple NMR signals may be acquired in the same pulse sequence. The echo-planar pulse sequence was proposed by Peter Mansfield (J. Phys. C. 10: L55-L58, 1977). In contrast to standard pulse sequences, the echo-planar pulse sequence produces a set of NMR signals for each RF excitation pulse. These NMR signals can be separately phase encoded so that an entire scan of 64 views can be acquired in a single pulse sequence of 20 to 100 milliseconds in duration. The advantages of echo-planar imaging ("EPI") are well-known, and this method is commonly used where the clinical application requires a high temporal resolution. Echo-planar pulse sequences are disclosed in U.S. Pat. Nos. 4,678,996; 4,733,188; 4,716,369; 4,355,282; 4,588,948 and 4,752,735.
A variant of the echo-planar imaging method is the Rapid Acquisition Relaxation Enhanced (RARE) sequence which is described by J. Hennig et al in an article in Magnetic Resonance in Medicine 3, 823-833 (1986) entitled "RARE Imaging: A Fast Imaging Method for Clinical MR." The essential difference between the RARE (also called a fast spin-echo or FSE) sequence and the EPI sequence lies in the manner in which NMR echo signals are produced. The RARE sequence, utilizes RF refocused echoes generated from a Carr-Purcell-Meiboom-Gill sequence, while EPI methods employ gradient recalled echoes.
Other MRI pulse sequences are known which sample 2D or 3D k-space without using phase encoding gradients. These include the projection reconstruction methods known since the inception of magnetic resonance imaging and again being used as disclosed in U.S. Pat. No. 6,487,435. Rather than sampling k-space in a rectilinear, or Cartesian, scan pattern by stepping through phase encoding values as described above and shown in FIG. 2, projection reconstruction methods sample k-space with a series of views that sample radial lines extending outward from the center of k-space as shown in FIG. 3. The number of projection views needed to sample k-space determines the length of the scan and if an insufficient number of views are acquired, streak artifacts are produced in the reconstructed image. There are a number of variations of this straight line, radial sampling trajectory in which a curved path is sampled. These include spiral projection imaging and propeller projection imaging.
Recently, parallel MRI scanning methods using spatial information derived from the spatial distribution of the receive coils and a corresponding number of receiver channels has been proposed to accelerate MRI scanning. This includes the k-space sampling methods described in Sodickson D K, Manning W J, "Simultaneous Acquisition Of Spatial Harmonics (SMASH)" Fast Imaging With Radiofrequency Coil Arrays", Magn. Reson. Med. 1997; 38(4):591-603, or Griswold M A, Jacob P M, Heidemann R M, Nittka M, Jellus V, Wang J, Kiefer B, Hasse A, "Generalized Autocalibrating Partially parallel Acquisitions (GRAPPA)", Magn. Reson. Med. 2002; 47(6):1202-1210, or Pruessmann K P, Weiger M, Scheidegger M B, Boesiger P, "SENSE: Sensitivity Encoding For Fast MRI", Magn. Reson. Med. 1999; 42(5):952-962, all of which share a similar theoretical background. Parallel MRI accelerates image data acquisition at the cost of reduced signal-to-noise ratio (SNR). The temporal acceleration rate is limited by the number of coils in the array and the number of separate receive channels, and the phase-encoding schemes used. Typically, acceleration factors of 2 or 3 are achieved.
Mathematically, the attainable acceleration in parallel MRI is limited by the available independent spatial information among the channels in the array. The parallel MRI image reconstruction manifests itself as a problem in solving an over-determined linear system using this spatial information. Therefore, advances in the coil array design with more coil elements and receiver channels can increase the acceleration rate when using the parallel MRI technique. Recently, optimized head coil arrays have been extended from 8-channel as described in de Zwart J A, Ledden P J, Kellman P, van Gelderen P. Duyn J H, "Design Of A SENSE-Optimized High-Sensitivity MRI Receive Coil For Brain Imaging", Magn. Reson. Med. 2002; 47(6):1218-1227, to 16-channel as described in de Zwart J A, Ledden P J, van Gelderen P, Bodurka J, Chu R, Duyn J H, "Signal-To-Noise Ratio And Parallel Imaging Performance Of A 16-Channel Receive-Only Brain Coil Array At 3.0 Tesla", Magn. Reson. Med. 2004; 51(1):22-26, as well as 23 and 90-channel arrays as described in Wiggins G C, Potthast A, Triantafyllou C, Lin F-H, Benner T, Wiggins C J, Wald L L, "A 96-Channel MRI System With 23- and 90-Channel Phase Array Head Coils At 1.5 Tesla", 2005; Miami, Fla., USA, International Society for Magnetic Resonance in Medicine, p 671.
As described recently by McDougall M P, Wright S M, "64-Channel Array Coil For Single Echo Acquisition Magnetic Resonance Imaging", Magn. Reson. Med. 2005; 54(2):386-392, a dedicated 64-channel linear planar array was developed to achieve 64-fold acceleration using a single echo acquisition (SEA) pulse sequence and a SENSE reconstruction method. The SEA approach depends on the linear array layout and localized RF coil sensitivity in individual receiver channels to eliminate the phase encoding steps required in conventional imaging. The challenge of this approach is the limited sensitivity in the perpendicular direction to the array plane and the extension of the methodology to head-shaped geometries.

Dynamic magnetic resonance inverse imaging


A transmission for a motorcycle utilizing an automotive engine. The transmission has a torque converter that serves as a fluid coupling to the engine and multiplies torque at low speeds. A valve is manually operable as by a foot pedal to lock-up a pressure plate in the converter when a predetermined speed is reached so a direct mechanical connection is established between the engine output and the transmission power output via an axially extending main shaft. The transmission power output includes a bevel gear arrangement which drives an output shaft which is 90.degree. with respect to the axis of the transmission.

Field of the Invention
The present invention relates to a transmission and more particularly relates to a transmission, particularly for a motorcycle, which has a torque converter which operates to couple the engine to the output shaft at low speeds and which at higher speeds establishes a direct mechanical connection between the engine and the output shaft.
Some motorcycles utilize automotive engines such as Chevrolet V-6 or V-8 engines. Currently there are approximately ten manufacturers of automotive engine power motorcycles on the market. Representative of these is the Kannon V-cycle which is manufactured using both V-6 and V-8 engines. Motorcycles with engines of this type share a common problem. In order to travel at speeds of less than thirteen miles per hour, the motorcycle rider must slip a hand-held clutch. Since there is no neutral lock-out, the motorcycle remains in gear at all times. This results in serious disadvantages as the rider does not have full control of the motorcycle when the clutch is in the slipped position. Further problems can arise if the rider accidently releases the clutch suddenly engaging the transmission causing the motorcycle to lurch causing a loss of control. Another problem attendant to conventional transmissions used with large block motorcycles is that slipping the clutch results in unnecessary and premature wear of the clutch mechanism.
In view of the foregoing, there is a demonstrated need for an improved mechanism for shifting motorcycles of the type utilizing automotive engines which is safer, effective and convenient to use.
There are a number of motorcycle transmissions commercially available and the patent literature discloses a number of drive mechanisms which are represented by the following:
U.S. Pat. No. 2,943,515 discloses a power transmitting apparatus, particularly one employing a hydro-kinetic type of torque transmitting unit in combination with a chain speed gear box transmission unit with a plurality of selectively operable clutch means. PA1 U.S. Pat. No. 4,079,820 discloses a rotary power transmission having a hydrodynamic speed or torque converter or other fluid coupling in combination with a magnetically actuated friction clutch. The friction clutch is accommodated inside the housing of the fluid coupling and the magnet which actuates the friction clutch located outside the housing and the magnetic field generated is effective through the housing. PA1 U.S. Pat. No. 4,673,071 discloses a power delivery system which includes an input shaft and an output shaft disposed concentrically with the input shaft, a fluid coupling and a power cut-off device interposed between the input and output shafts. The case containing the fluid coupling is located on a radial inner side of the fluid coupling and an oil pump for supply of oil into the fluid coupling case is positioned within the case adjacent the radially inward periphery of the power cut-off device. PA1 U.S. Pat. No. 4,733,761 discloses a power delivery system including an input shaft for transmitting driving power of an engine, an output shaft mounted concentrically with the input shaft, a pump mounted concentrically between the input and output shaft and connected to the input shaft, a fluid coupling having a turbine connected to the output shaft, the case containing the fluid coupling and a power cut-off device. The power cut-off device is provided with a frictional coupling element and a servo mechanism. PA1 U.S. Pat. No. 4,667,762 discloses a drive mechanism for a motorcycle having a rear wheel which is supported by a trailing arm and is driven by a drive that includes an intermediate shaft that is rotatably journaled on the trailing arm. One end of the intermediate shaft is driven from the engine output shaft by a drive shaft and the other end of the intermediate shaft drives the rear wheel through a chain. The chain is positioned a substantially greater distance outwardly of the longitudinal center line of the motorcycle than is the drive shaft so as to afford good driver position and a relatively narrow width. PA1 U.S. Pat. No. 5,263,549 also discloses a motorcycle shaft drive mechanism and a drive gear located on a drive shaft for rotation and axle gear located on the rear axle for driving the rear axle. A pinion shaft is provided having a front pinion gear matching the drive gear and a rear pinion gear matching the rear axle so that when the drive shaft is driven, the force supplied by the drive gear to the front pinion gear creates a moment on the pinion shaft about the drive shaft which is opposite to and balances the moment on the pinion shaft about the rear axle.

Motorcycle transmission with torque converter


Disclosed are methods and compositions for maintaining the integrity of the gastrointestinal tract luminal lining in a mammal, including (1) limiting epithelial cell proliferation, (2) inhibiting ulcerative lesion formation, (3) inhibiting inflammation normally associated with ulcerative diseases, and (4) stimulating the repair of ulcerative lesions and the regeneration of the luminal tissue. The methods and compositions include a therapeutically effective amount of a morphogen as defined herein.

The luminal lining of the mammalian gastrointestinal tract (GI tract), which extends from the mouth cavity to the rectum, includes a protective layer of continually proliferating basal epithelial cells overlying a mucosal layer. Together, the basal epithelium and mucosa create the protective "gastrointestinal barrier." Disruption of this barrier results in lesions that can become infected and/or expose underlying tissue to the corrosive effect of gastric juices. Gastrointestinal ulcerations can cause oral mucositis, gastric ulcers, necrotizing enterocolitis, regional ileitis, ulcerative colitis, regional enteritis (Crohn's disease), proctitis, and other forms of inflammatory bowel disease (IBD).
Ulcerative oral mucositis is a serious and dose-limiting toxic side effect of many forms of cancer therapies, including chemotherapy and radiation therapy. Oral mucositis accounts for significant pain and discomfort for these patients, and ranges in severity from redness and swelling to frank ulcerative lesions. Chemotherapeutic agents and radiation can kill or damage the epithelial cells lining the oral cavity. Such damage includes the inhibitory effect that chemotherapeutic agents may have on mitoses of the rapidly dividing cells of the oral basal epithelium. The severity of damage is related to the type and dose of chemotherapeutic agent(s) and concomitant therapy such as radiotherapy. Further, ulceration is hastened if sources of chronic irritation such as defective dental restorations, fractured teeth or ill-fitting dental prostheses are present. Oral mucositis most often affects the nonkeratinized mucosa of the cheeks, lips, soft palate, ventral surface of the tongue and floor of the mouth, approximately one to two weeks after cancer therapy. The lesions often become secondarily infected and become much harder to heal. The disruption in the oral mucosa results in a systemic portal of entry for the numerous microorganisms found in the mouth. Consequently, the oral cavity is the most frequently identifiable source of sepsis in the granulocytopenic cancer patient. Of primary concern are those patients undergoing: chemotherapy for cancer such as leukemia, breast cancer or as an adjuvant to tumor removal; radiotherapy for head and neck cancer; and combined chemotherapy and radiotherapy for bone marrow transplants.
One source of oral mucositis can result from xerostomia, or chronic mouth dryness, which typically results from diminished or arrested salivary secretion or asialism. Salivary gland dysfunction or atrophy may result from tissue senescence in aged individuals, or from an organic disorder. Most frequently, xerostomia is an undesired side effect of a clinical or pharmaceutical therapy. Normally, saliva moistens the oral mucosal membrane, allowing for the dissolution and limited absorption of exogenous substances introduced into the oral cavity. In xerostomaic individuals irritating exogenous substances, including foods and medications, remain exposed to the mucosa and can cause inflammation and ulceration. A description of xerostomia-causing medications is described in Gallager, et al. (1991) Current Opinion in Dentistry 1:777-782.
Current therapy for mucositis is limited to either local or systemic palliation or topical anti-bacterial therapy. At present there is no effective treatment for mucositis. Therapy typically is limited to pain medications and treatment of secondary infection. In particular, recommendations have included treatment with topical anesthetics such as xylocaine, benzocaine and cocaine, treatment with solutions which coat the ulcerative lesions with a polysaccharide gel and use of antiseptic solutions such as Chlorhexadine. While all these treatments do provide some relief, none are directed to the actual healing of oral mucositis, which entails directly healing the mucosal epithelium cells.
Recently, certain local-acting growth factors, such as TGF-.alpha. have been shown to have some effect on ulcerative mucositis lesions at low concentrations, but less effect at higher concentrations (see U.S. Pat. No. 5,102,870, issued Apr. 7, 1992 to Florine et al.) The biphasic effect exhibited by such factors may limit their clinical utility. There remains a need for a therapy that inhibits ulcerative mucositis lesion formation and significantly enhances healing of lesions following their formation.
Gastrointestinal ulcer disease, in particular, peptic ulcers, affect 5-15% of the United States population. Peptic ulcers include gastric ulcers, which occur as lesions in the wall of the stomach, and duodenal ulcers, which are deep lesions that occur in the wall of the duodenum, i.e., the upper portion of the small intestine. Another ulcer disease, particularly worrisome to pediatricians, occurs in the premature infants. This condition, known as necrotizing enterocolitis, affects 10-15% of newborns having a birth weight of under 1.5 kg and results in severe ulceration of the small intestine, which frequently requires surgery. Gastric ulcers can result from an imbalance in factors which maintain the natural gastrointestinal barrier, including factors which neutralize corrosive gastric juices, such as the mucous bicarbonate, and other factors which protect the body from luminal damaging agents. Although current antiulcer therapeutics, including antisecretory products such as cimetidine and ranitidine, appear to be effective in healing duodenal ulcers, it is generally believed that they are effective because they reduce normal gastric acid secretion. While the reduction in acidity aids in the closure of the ulcer, it also interferes with normal digestion. Accordingly, a high percentage of ulcers healed with current therapies recur within one year of therapy. The high rate of ulcer recurrence is thought to be at least partially attributable to the reduced number of mucus-producing cells in the scar tissue which is left at the site of the healed ulcer, rendering the area more vulnerable to rupture when the gastointestinal acidity returns to normal.
PCT Application No. PCT/US89/03467 discloses the use of an acid-resistant local-acting fibroblast growth factor to treat GI ulcers. U.S. Pat. No. 5,043,329 discloses the use of phospholipids to treat ulcers of the gastrointestinal tract.
Severe ulceration of the gastrointestinal mucosa also can spontaneously occur in the lower bowel (distal ileum and colon) in a spectrum of clinical disorders called inflammatory bowel disease (IBD). The two major diseases in this classification are ulcerative colitis and regional enteritis (Crohn's Disease) which are associated with severe mucosal ulceration (frequently penetrating the wall of the bowel and forming strictures and fistulas), severe mucosal and submucosal inflammation and edema, and fibrosis. Other forms of IBD include regional ileitis and proctitis. Clinically, patients with fulminant IBD can be severely ill with massive diarrhea, blood loss, dehydration, weight loss and fever. The prognosis of the disease is not good and frequently requires resection of the diseased tissue.
It is an object of this invention to provide methods and compositions for maintaining the integrity of the gastrointestinal luminal lining in a mammal. Another object is to provide methods and compositions for regenerating basal epithelium and mucosa in ulcerated gastrointestinal tract barrier tissue, including the oral mucosa. Another object of the invention is to provide tissue protective methods and compositions that allow extension or enhancement of a chemical or radiotherapy. Another object is to provide methods and compositions capable of limiting the proliferation of epithelial cells, particularly the basal epithelial cells of the gastrointestinal tract. Still another object is to provide methods and compositions for substantially inhibiting inflammation normally associated with ulcerative diseases. Another object is to provide methods and compositions for protecting mucosal tissue from the tissue destructive effects associated with xerostomia. Yet another object is to provide methods and compositions for the treatment of oral mucositis, peptic ulcers, ulcerative colitis, regional enteritis, necrotizing enterocolitis, proctitis and other ulcerative diseases of the gastrointestinal tract.
These and other objects and features of the invention will be apparent from the description, drawings, and claims which follow.

Morphogen treatment of gastrointestinal ulcers


An engine controller executes the feedback control of an amount of the fuel injected, such that an air-fuel ratio (A/F) of the exhaust gas approaches a theoretical ratio. The amount of the fuel injected is as a function of a changeable feedback correction factor (FAF). When the engine is in a predetermined condition in which the engine controller interrupts the feedback control, a secondary air supplier supplies secondary air from an intake passage to an exhaust passage, and changes the A/F ratio of the exhaust gas. Furthermore, when the engine controller executes the feedback control operation, the secondary air is temporarily supplied to the exhaust passage, for the purpose of diagnosis of the supplier. The diagnostic system detects a first feedback correction factor before the secondary air is supplied, and a second feedback correction factor after the secondary air has been supplied, and calculates a deviation value therebetween. The system determines that the secondary air supplier is malfunctioning, when the deviation value (.DELTA.FAF) is smaller than a predetermined value (.alpha.).

1. Field of the Invention
The present invention generally relates to a secondary air supplier for use in a vehicular engine. More particularly, the present invention pertains to a diagnostic system for diagnosing the condition of the secondary air supplier. The air supplier supplies secondary air to an exhaust passage of the engine, in order to purify the exhaust gas.
2. Description of the Related Art
Conventional exhaust gas purification techniques generally utilize an oxygen sensor and a three way catalytic converter, in order to satisfy two requirements. The first requirement is to satisfy the regulatory rules, and the other requirement is to minimize the engine fuel consumption. These conventional techniques include oxidizing and/or deoxidizing the carbon monoxide (CO), hydro-carbon (HC) and nitrogen oxides (NOx), contained in the exhaust gas, in order to purify it. In order to efficiently complete these reactions, the air-fuel ratio in the engine should be maintained at about a theoretical air-fuel ratio. The concept for maintaining the theoretical air-fuel ratio has been embodied in several engine systems.
An exemplary engine system of this type includes an engine control unit, an oxygen sensor disposed along an exhaust passage, and a secondary air supplier for directly supplying the secondary air from an intake passage to the exhaust passage. The control unit calculates the air-fuel ratio (A/F) of the air-fuel mixture in the engine cylinders based on the output signal from the oxygen sensor. Further, the control unit executes a closed loop control operation (i.e., feedback control operation) for controlling the supplied amount of air and/or fuel. As a result of this control, the air-fuel ratio approaches the theoretical air-fuel ratio.
In order to execute the above-described closed loop control operation, a feedback correction factor (FAF) is utilized for calculating a target supplied amount of air and/or fuel. The feedback correction factor (FAF) could vary in relation to the detected result of an oxygen sensor. While the air-fuel ratio (A/F) is controlled to approach the theoretical air-fuel ratio, the feedback correction factor (FAF) alters, where the value "1.0" is the center of variation.
When the engine is operating under specific conditions, the secondary air is supplied to the exhaust passage by means of the secondary air supplier, in order to warm up the catalyst (i.e., in order to activate the catalyst).
The following are illustrative specific operation conditions of the engine: a condition wherein the coolant temperature is still cold; and a condition wherein. The control unit executes an open loop control operation for the air-fuel ratio (A/F), while the secondary air is being supplied. The control unit re-executes the closed loop control operation for the air-fuel ratio simultaneously with the termination of the secondary air supply.
In this conventional engine system, the exhaust emission could become faulty when the secondary air supplier malfunctions.
The Japanese Unexamined Patent Publication No. 63-143362 proposes a diagnostic system for diagnosing whether or not the secondary air supplier is functioning properly. In this system, the secondary air supplier is forcibly activated when the closed loop control operation for controlling the amount of fuel injected is executed. The secondary air is supplied to the exhaust passage by means of the secondary air supplier. Further, a mean value of the feedback correction factor (FAF) will be calculated. When the calculated mean value becomes smaller than a fundamental value ("1.0") for a predetermined period of time, the diagnostic system determines that the secondary air supplier is malfunctioning.
However, in the engine system which is executing the closed loop control operation for the amount of fuel injected, when the engine is operating in a constant speed condition, the feedback correction factor (FAF) approaches the fundamental value "1.0". When a vehicle is varying its engine condition (e.g. decelerating), the feedback correction factor (FAF) might largely shift away from the fundamental value "1.0".
In other words, the amount of fuel injected by the fuel injector is calculated in the following way: a fundamental amount of fuel injected is determined by taking a ratio (intake amount/engine speed), and is adjusted by the feedback correction factor (FAF), which is determined in relation to the result detected by the oxygen sensor. The amount of the air intake is a value measured by an air flowmeter. Accuracy of measurement by this air flowmeter tends to vary specifically, when the amount of air intake is decreased in response to a change of operating conditions of the engine, from the constant speed operating condition to the decelerating condition. Therefore, while the vehicle is decelerating, the feedback correction factor (FAF) might largely shift away from the fundamental value "1.0".
Therefore, if the secondary air is supplied while the feedback correction factor temporarily and largely shifts away from the fundamental value "1.0", the mean value of the feedback correction factor, for use in a diagnostic operation, might become smaller than the predetermined value for a predetermined period of time. According to the conventional technology which simply compares the mean value of the feedback correction factor (FAF) with the predetermined value, the diagnostic system might erroneously determine that the secondary air supplier is malfunctioning, even when the secondary air supplier is properly functioning.

Diagnostic system for a secondary air supplier in an engine


Implementations set forth herein relate to an automated assistant that operates according to a variety of different location-based biasing modes for rendering responsive content for a user and/or proactively suggesting content for the user. The user can provide condensed spoken utterances to the automated assistant, when the automated assistant is operating according to one or more location-based biasing modes, but nonetheless receive accurate responsive outputs from the automated assistant. A responsive output generated by biasing toward a subset of location characteristic data that has been prioritized over other subsets of location characteristic data. The biasing allows the automated assistant to compensate for any details that may be missing from a spoken utterance, but allows the user to provide shorter spoken utterances, thereby reducing an amount of language processing when processing inputs from the user.

Humans may engage in human-to-computer dialogs with interactive software applications referred to herein as "automated assistants" (also referred to as "digital agents," "chatbots," "interactive personal assistants," "intelligent personal assistants," "conversational agents," etc.). For example, humans (which when they interact with automated assistants may be referred to as "users") may provide commands and/or requests using spoken natural language input (i.e., utterances) which may in some cases be converted into text and then processed, and/or by providing textual (e.g., typed) natural language input.
When a user is visiting a point of interest, a user may provide a number inquiries to an automated assistant in order to retrieve information and/or perform particular actions associated with the point of interest to which they are visiting. However, given the limited battery charge of most portable electronic devices, frequent and/or prolonged inputs to an automated assistant can consume energy resources as well as computational resources at a corresponding portable electronic device. Such limitations can be especially problematic when a user is in an unfamiliar area, unable to access mains power for recharging their portable electronic device, and/or unable to speak a language that is native to the area, thereby limiting their access to information when their portable electronic device is without battery charge. Furthermore, when visiting an unfamiliar area, the user may not recognize the most useful accommodations for their visit until they have reached the end of their visit. As a result, the user may have expended certain resources unnecessarily because of their unfamiliarity with certain available accommodations such as train schedules, help desks, restroom locations, hospitals, charging stations, and/or any other accommodations that can be useful during a visit. Although a user can inquire about certain accommodations from their respective automated assistant, such frequent and/or prolonged inquiries can consume energy and other computational resources, thereby expediting battery drain of their respective portable electronic device.

Location-based mode(s) for biasing provisioning of content when an automated assistant is responding to condensed natural language inputs


Bacillus thuringiensis cultures deposited as NRRL B-18747, NRRL B-18749 and NRRL B-18750 have dipteran activity. Thus, these cultures, or mutants thereof, can be used to control such insect pests. Further, genes encoding novel .delta.-endotoxins can be removed from these cultures and transferred to other host microbes, or plants. Expression of the .delta.-endotoxins in such hosts results in the control of susceptible insect pests in the environment of such hosts.

Many hundreds of strains of Bacillus thuringiensis (B.t.) produce insecticidal toxins designated as delta endotoxins. They are synthesized by sporulating B.t. cells. When toxin is ingested by a susceptible insect, the cells of the gut epithelium are destroyed.
The reported activity spectrum of B.t. covers insect species within the orders Lepidoptera and Coleoptera, many of which are major pests in agriculture and forestry. The activity spectrum also includes the insect order Diptera, which includes mosquitoes and black flies. See Couch, T. L. (1980) "Mosquito Pathogenicity of Bacillus thuringiensis var. israelensis," Developments in Industrial Microbiology 22:61-76; Beegle, C.C. (1978) "Use of Entomogenous Bacteria in Agroecosystems," Developments in Industrial Microbiology 20:97-104. Dipteran insects are serious nuisances as well as being vectors of many serious human and animal diseases such as malaria, onchocerciasis, equine encephalitis, and dog heartworm.
The two varieties of B.t. known to kill mosquitos and blackflies are B.t. israelensis (B.t.i.) (Goldberg, L.J., J. Margalit [1977] Mosquito News 37:355-358) and B.t. morrisoni (B.t.m.) (Padua, L.E., M. Ohba, K. Aizawa [1984] J. Invertebrate Pathology 44:12-17). These are not harmful to non-target organisms (Mulla, M. S., B. A. Federici, H. A. Darwazeh [1982] Environmental Entomology 11:788-795), and play an important role in the integrated management of dipteran pests. They are safe to use in urban areas, and can be used in aquatic environments without harm to other species.
Dipteran pests are also a major problem in the poultry and cattle industries. The horn fly, a serious cattle pest, is killed by B.t. in the larval stages (Temeyer, K.B. [1990] "Potential of Bacillus thuringiensis for fly control," Fifth International Colloquium on Invertebrate Pathology and Microbial Control, Society for Invertebrate Pathology, 352-356). European Patent Application 90307204.9 (Publication No. 0 409 438) discloses Bacillus thuringiensis dipteran-active isolates PS71M3 and PS123D1.
Flies are an abundant species that can be found almost everywhere. They usually occur in such large numbers as to constitute a nuisance. The majority of the Diptera are considered pests and are of economic importance. A number of adult species are blood-sucking and cause irritation to man and his domestic animals. Others are scavenging flies that mechanically transmit organisms and pathogens that contaminate food. Both types of flies are important vectors of disease, such as malaria, yellow fever, filariasis, sleeping sickness, typhoid fever, and dysentery. Larvae of a few species are pests of major agriculture crops. The larvae can feed on all parts of the plant such as seeds, roots, leaves and fruits. Larvae of certain species feed on fungus causing damage to mushroom production. Larvae can irritate domestic animals when they develop in the animal. Both the adults and larvae are considered pests to man and agriculture.
House flies (family Muscidae) are an important pest from the order Diptera. They are considered a nuisance and are vectors of human and animal diseases. Their habits of walking and feeding on garbage and excrement and on the human person and food make them ideal agents for the transfer of disease organisms (Metcalf, C. and Flint, W. 1962. Destructive and Useful Insects, McGraw-Hill Book Co., N.Y., pp. 1030-1035.). This species can also be a pest to animals and transmit disease through open wounds. Muscidae also include the little house fly, face fly, stable fly, and horn fly, all of which are pests of livestock. These species are pests of cattle, poultry, horses and other types of livestock. They breed in manure and decaying straw located near the animals. The horn and stable flies are biting flies which cause stress to dairy cattle reducing milk production. The family Muscidae is considered an economic problem domestically and worldwide.
Leafmining flies cause damage and yield loss to economically important crops such as potatoes, tomatoes and celery. Dipteran leafminers are also considered a major pest in the ornamental flower industry (Parrella, M. P. 1987. Biology of Liriomyza. Ann. Rev. Entomol. 32:201-224). The most common leafminers are found in the family Agromyzidae although the families Anthomyiidae, Drosophilidae and Ephydridae also contain leafmining flies (Hespenheide, H. A. 1991. Bionomics of leafmining insects. Ann. Rev. Entomolo. 36:535-60). Flies in the genus Liriomyza (also known as serpentine leafminers) are particularly important because of their worldwide distribution, polyphagous nature and resistance to insecticides. In the state of California, the chrysanthemum industry lost approximately 93 million dollars to Liriomyza trifolii between the years of 1981-1985.
There are also dipteran pests of plants, such as Hessian fly, Medfly, and Mexfly, for which a B.t. product would be very valuable.

Bacillus thuringiensis isolates active against dipteran pests


An apparatus and method for baking dough capable of easily adjusting the texture of dough without changing the mixture of ingredients of the dough. The apparatus includes a microwave irradiation part provided with a downstream belt conveyor and an upstream belt conveyor which is disposed immediately before the downstream belt conveyor and moves slower than the downstream belt conveyor. When the apparatus is incorporated into a crumb production line or bread production line, crumbs and bread having different dough textures can be easily baked.

1. Field of the Invention
The present invention relates to a method and apparatus for baking dough, more particularly to those capable of adjusting the texture of dough.
2. Description of related art
The consumption of bread in Japan has recently increased without distinction of age or sex, and demand for bread has also increased.
Meanwhile, there has been a large demand for diversification of products in the field of foodstuffs, and the quality of bread has improved.
Particularly, dough is considered as a first point or first step of the baking process, and the quality thereof in terms of fragrance, color, resistance to the teeth, palate, etc. delicately influences mouth feeling or sensations experienced during eating.
Meanwhile, mouth feeling largely depends on the texture of dough which is a microscopic structure of dough. This is caused by the fact that the resistance to the teeth when eating bread depends on the structure of the texture of dough. It is a knowledge in the field of art that the texture of dough is slightly varied owing to the difference of mixture of ingredients. The difference of mixture of ingredients includes the difference of ratio of ingredients and the difference of raw materials or ingredients per se (hereinafter referred to simply as mixture of ingredients). It is possible to adjust the texture of dough positively utilizing the difference of mixture of ingredients.
However, there is a limit to vary the texture of dough depending on the mixture of ingredients, which causes changes in taste, and hence this is not necessarily an appropriate method.
Accordingly, it is very useful that if the texture of dough can be intentionally adjusted on the production line for baking bread without resorting to the mixture of ingredients of dough, but it has not been developed so far. The present invention has been created under such a background.

Method of and apparatus for baking dough


A method is for producing a three-dimensional vehicle door frame inner reinforcement element (52) including an inner center pillar part (66), an inner front pillar part (68) and an inner side rail part (64) joining the inner center pillar part (66) and the inner front pillar part (68). The method includes providing an inner center pillar blank, an inner front pillar blank and an inner side rail blank, said inner blanks being substantially planar, assembling the inner center pillar blank and the inner front pillar blank to the inner side rail blank in order to form a substantially planar door frame inner reinforcement blank, and hot stamping the door frame inner reinforcement blank to shape the three-dimensional door frame inner reinforcement element (52).

Conventionally, vehicles comprise reinforcement elements destined to protect the vehicle occupants in case of an impact, in particular a side impact, a front impact or a roof crush during a rollover accident, by limiting intrusions of any kind in the vehicle passenger compartment.
The reinforcement elements comprise, on each side of the vehicle, a body side structure forming a door frame, which is conventionally made of steel. The door frame is a three-dimensional part generally comprising several sections, including a side rail, a center pillar, a front pillar and a lowerside sill, which together define a door opening.
Reducing the overall weight of the vehicle is very desirable in order to reduce the energy consumption, so as to meet the future environmental requirements. It is thus desirable to reduce the thickness of the parts forming the vehicle, in particular the reinforcement elements, including the door frame.
However, simply reducing the thickness of the reinforcement elements generally leads to a degraded protection of the vehicle occupants against intrusions.
Steels having better mechanical properties such as yield strength or tensile strength may be used. Indeed, such steels provide an enhanced protection that lower grade steels for a given thickness. However, such steels generally have a lower formability.
Besides, it is known to produce a door frame by cutting a steel sheet to form a flat blank with the desired dimensions, and to stamp the flat blank so as to shape the door frame to the desired final three-dimensional shape. However, this method involves important off-cuts, and thus material losses. Moreover, this method implies a uniform thickness for the whole door frame, whereas specific thicknesses may be desirable for each section of the door frame as a function of the mechanical stresses the section may be subjected to. Hence, this method implies that some of the sections of the door frame are thicker than necessary, which results in a higher weight for the door frame.
To solve this problem, it has been proposed to produce a door frame by stamping several blanks separately, so as to form stamped parts, and by assembling the stamped parts so as to form the door frame. The assembling is generally performed by spot welding. Indeed, the parts, once stamped, are subjected to elastic recovery, so that the precise alignment of the edges of the parts required by laser welding can generally not be achieved. However, spot welding results in the formation of discontinuous results weld joints which may impair the resistance of the door frame.

Methods for producing a three-dimensional vehicle door frame inner reinforcement element, for producing a vehicle door frame and for producing a vehicle reinforcement structure


Provided is a plasma diagnostic apparatus having a probe unit, which is inserted into a plasma or disposed at boundary of a plasma, the apparatus including: a signal supplying unit having a signal supplying source; a current detecting/voltage converting unit for applying a periodic voltage signal applied from the signal supplying unit to the probe unit, detecting the magnitude of the current flowing through the probe unit, and converting the detected current into a voltage; and a by-frequency measurement unit for computing the magnitude and phase of individual frequency components of the current flowing through the probe unit by receiving the voltage output from the current detecting/voltage converting unit as an input.

Among equipments used to manufacture semiconductor devices, a plasma apparatus is widely used for forming plasma in a closed chamber of vacuum state, depositing a thin film on a wafer by injecting a reaction gas, and etching a thin film formed on a wafer.
The plasma apparatus has various advantages in that when the deposition process is performed using the plasma, the deposition process can be performed in a low temperature which does not allow impurities formed in the wafer to further diffuse, and the thickness uniformity of the thin film formed on a large-sized wafer is excellent, and that when the etch process is performed, the etch uniformity of the thin film across the wafer is excellent. Accordingly, the plasma apparatus is widely used.
A Langmuir probe is most widely used to measure plasma parameters in the plasma of a plasma apparatus and determine plasma characteristics and ion and electron distribution.
There are three types of Langmuir probes: a single Langmuir probe, a double Langmuir probe and a triple Langmuir probe. The Langmuir probe may be used to obtain a current-voltage characteristic curve of the plasma by inserting the probe made from metal in the plasma, applying a voltage to the probe, and measuring a current flowing through the probe.
For example, in the single probe, the current-voltage curve is expressed as Equation (1):
                                          I            P                    =                                    I              +                        -                                          I                -                                                          exp                                                  [                                                                                V                        B                                            -                                              V                        P                                                                                T                      e                                                        ]                                                                    ,                            (        1        )            where I+, I−, VB, VP are an ion saturation current, an electron saturation current, a probe potential and a plasma potential respectively. That is, as the probe potential increases, the current flowing through the probe increases exponentially.
Also, in the double probe, the current-voltage curve is expressed as Equation (2):
                              I          P                =                              I            +                                                        tanh                                            (                                                      V                    B                                                        2                                                              T                      e                                                                      )                                      .                                              (        2        )
Data such as an ion saturation current, an electron saturation current, an electron temperature, a plasma potential, and the like can be obtained from each of the current-voltage characteristic curves. Such a method is simple, but it has an inconvenience in that the current-voltage curve must be obtained, and that a separate signal processing is required for obtaining this data.
Also, when an insulator layer is formed on the probe surface through the deposition in the plasma, the biggest problem is that the probes cannot operate correctly, whereby the current-voltage curve cannot be obtained. Further, it is the most important requirement that a measurement object in the plasma diagnostic not be influenced by any effects, such as perturbation. However, since many charges in the plasma are extracted, the object is influenced by perturbation. Furthermore, real-time plasma analysis is also difficult.
Meanwhile, while there have been various attempts to diagnose the plasma using the nonlinearity of a plasma sheath, such attempts have failed to obtain satisfactory results. There is a method for measuring an electron temperature approximately using the nonlinearity in a nuclear fusion plasma such as Tokamak.
The method is more specifically explained in below.
After floating the probe inserted into the plasma in a plasma chamber using a DC current blocking capacitor, if a sine-wave voltage is applied, the current flowing through the probe is expressed as Equation (3):ipr=i+−i−exp [(VB−VP)/Te],  (3)
where Ipr is a current flowing through the probe, i+ and i− are an ion saturation current and an electron saturation current respectively, and VB, VP, and Te are a probe potential, a plasma potential and an electron temperature respectively.
i+,i− are expressed as Equation (4) and Equation (5) respectively:i+=0.61e niuBA,  (4)where, ni is an ion density, UB is a Bohm velocity, and A is a probe area. Further, e represents a charge of an electron, as is well known in the art.
                                          i            -                    =                                    1              4                                                  en              e                                                  v              e                                    A                          ,                            (        5        )            where ne is an ion density, and Ve is an electron velocity.
Accordingly, if the probe potential(VB) is VB= V+V0 cos wt, the current flowing through the probe is expressed as Equation (6):
                                          i            pr                    =                                    i              +                        -                                          i                -                                                          exp                                                  [                                                            (                                                                        V                          _                                                -                                                  V                          P                                                                    )                                        /                                          T                      e                                                        ]                                                                          exp                                                  [                                                                                V                        0                                                                    T                        e                                                                                cos                                                                                wt                                    ]                                                                    ,                            (        6        )            where V is a floating potential.
If the probe current(ipr) is expanded by a modified Bessel function. The result is expressed as Equation (7):
                                                                        i                pr                            =                                                                            i                  +                                -                                                      i                    -                                                                                exp                                                                    [                                                                              (                                                                                V                                _                                                            -                                                              V                                P                                                                                )                                                    /                                                      T                            e                                                                          ]                                                              [                                                                                I                          0                                                                                (                                                                                V                              0                                                                                T                              e                                                                                )                                                                    +                                              2                                                                                ∑                                                          k                              =                              1                                                        ∞                                                                                I                                k                                                                                (                                                                                V                                    0                                                                                T                                    e                                                                                )                                                                                cos                                                                                (                                                                  k                                                                                ω                                                                                t                                                                )                                                                                ]                                                                                =                                                                            i                  +                                -                                                      i                    -                                                                          exp                                                              [                                                                        (                                                                                V                              _                                                        -                                                          V                              P                                                                                )                                                /                                                  T                          e                                                                    ]                                                                                (                                                                  I                        0                                                                                (                                                                              V                            0                                                                                T                            e                                                                          )                                                              )                                                  -                                                                                i                  -                                                                                exp                                                              [                                                                        (                                                                                V                              _                                                        -                                                          V                              P                                                                                )                                                /                                                  T                          e                                                                    ]                                                        [                                      2                                                                                ∑                                                  k                          =                          1                                                ∞                                                                                I                            k                                                                                (                                                                                V                                0                                                                                T                                e                                                                                )                                                                                cos                                                                                (                                                          k                                                                                ω                                                                                t                                                        )                                                                                ]                                                                                =                                                                            i                  DC                                +                                  i                  AC                                                                                (        7        )
As shown by Equation (7), the probe current(ipr) consists of a DC current and an AC current.
As described later, if the probe is connected to the DC current blocking capacitor according to this invention, the DC current cannot flow.
Accordingly, the DC current(iDC) of the probe current(ipr) is expressed as Equation (8):
                              i          DC                =                              i            -                                          i                -                                                          exp                                                  [                                                            (                                                                        V                          _                                                -                                                  V                          p                                                                    )                                        /                                          T                      e                                                        ]                                                                          (                                                      I                    0                                                                          (                                                                  V                        0                                                                    T                        e                                                              )                                                  )                                              =          0.                                    (        8        )
Also, log is applied to Equation (8) and the result is obtained as Equation (9):
                                                        (                                                V                  _                                -                                  V                  p                                            )                                      T              e                                +                      log                                      (                                                I                  0                                                                  (                                                            V                      0                                                              T                      e                                                        )                                            )                                      =                              log                                      (                                                I                  +                                                  I                  -                                            )                                .                                    (        9        )
The floating potential is the potential between capacitors, and the plasma potential may be obtained from Equation (9) using the floating potential and the electron temperature. Also, the floating potential varies with V0, accordingly, after obtaining the floating potential variation (Δ V) with V0 changes, the electron temperature may be obtained using Equation (9). An approximate calculation equation is expressed as Equation (10):
                                          T            e                    =                                    -                              1                4                                                                                V                0                2                                            Δ                                                                                V                  _                                                                    ,                            (        10        )            where Δ V is a floating potential variation.
The AC current is expressed as Equation (11):
                              i          AC                =                                            -                              i                -                                                                exp                                            [                                                      (                                                                  V                        _                                            -                                              V                        P                                                              )                                    /                                      T                    e                                                  ]                                                                (                                                2                                                                              ∑                                              k                        =                        1                                            ∞                                                                                I                          k                                                                                (                                                                                V                              0                                                                                T                              e                                                                                )                                                                                cos                                                                          (                                                      k                                                                                ω                                                                                t                                                    )                                                                                +                …                            )                                =                                    -              2                                                  i              -                                                  exp                                            [                                                      (                                                                  V                        _                                            -                                              V                        P                                                              )                                    /                                      T                    e                                                  ]                                                                                [                                                                                I                          1                                                                                (                                                                                V                              0                                                                                T                              e                                                                                )                                                                                cos                                                                          (                                                      ω                                                                                t                                                    )                                                                                +                                                                                I                          2                                                                                (                                                                                V                              0                                                                                T                              e                                                                                )                                                                                cos                                                                          (                                                      2                                                        ω                                                                                t                                                    )                                                                                +                                                                                I                          3                                                                                (                                                                                V                              0                                                                                T                              e                                                                                )                                                                                cos                                                                          (                                                      3                                                        ω                                                                                t                                                    )                                                                                +                    …                                    ]                                =                                                      -                    2                                                                          i                    -                                                                                exp                                                                    [                                                                              (                                                                                V                                _                                                            -                                                              V                                P                                                                                )                                                    /                                                      T                            e                                                                          ]                                                                                [                                                                        i                          ω                                                +                                                  i                                                      2                                                        ω                                                                          +                                                  i                                                      3                                                        ω                                                                          +                        …                                            ]                                                                                (        11        )
Therefore, by comparing between the magnitudes of ω and 2 ω frequency components of the probe current, the result of the comparison is obtained as Equation (12):
                                                        i              ω                                      i                              2                                ω                                              =                                                                      I                  1                                                                  (                                                            V                      0                                        /                                          T                      e                                                        )                                                                              I                  2                                                                  (                                                            V                      0                                        /                                          T                      e                                                        )                                                      ≈                                                            4                                                        T                    e                                                                    V                  0                                                                                (                                                      when                                                                                V                      0                                                        <                                      T                    e                                                  )                                                    ,                            (        12        )            such that after measuring the magnitudes of ω and 2 ω frequency components, the electron temperature is obtained from Equation (12).
In such a method, in order to measure the electron temperature precisely, it is most important to precisely measure the magnitudes of individual frequency components of the probe current.
Conventionally, after converting a current signal into a voltage signal using a current probe (transformer), two frequency components of the current are obtained using ω and 2 ω Notch filters.

Korea Research Institute of Standards and Science