High-production, minimal-discharge aquaponic systems and methods. The aquaponic systems separate waste water generated from fish tanks into two flow streams. In the first flow stream, suspended-waste water generated from the waste water is converted to nutrient-rich water and used for hydroponic plant growth. Nutrient-depleted water resulting from the hydroponic plant growth is fed back into fish tanks to continue the cycle. In the second flow stream, settleable solids generated from the waste water is converted to nutrient-rich sludge and used for solid or semi-solid substrate-based plant growth. Excess nutrient-rich water derived from the second flow stream is fed back into the first flow stream, thereby conserving water and nutrients within the system.

Aquaponics is a sustainable method of food production that combines aquaculture (fish farming) with hydroponic plant production. The main method of aquaponics that is used in aquaponic food production is the raft system, which was primarily developed at the Agriculture Experiment Station, University of the Virgin Islands over a 30 year period.
Conventional aquaponic systems typically include multiple fish tanks, raft tanks in which the plants are grown, and basic filtration components. Examples of conventional aquaponic systems are described in U.S. Pat. Pub. 2010/0031893 to Bodlovich et al. and U.S. Pat. Pub. 2009/0301399 to Brown et al. Nitrification, a process that generates nitrogen, is conventionally performed directly in the raft tanks. Conventional aquaponic raft systems typically produce daily discharge of water and fish waste. This discharge discards material that could otherwise be used to increase plant production.
There is a need for an aquaponic system that nearly eliminates the water and waste discharge associated with conventional aquaponic systems and increases plant production.


A method for producing a customized helmet including a computer designed composite helmet liner to be incorporated into existing and new helmet designs is provided by scanning a user's cranial region, creating a computer rendering surface model of the scan, modifying the surface model using computer aided design software, overlaying and aligning an outer helmet shell model onto the modified cranial model to define the custom liner three-dimensional space to configure the composite liner with a software algorithm including shock absorbing segments having optimal sizes, shapes, and materials, fabricating the liner in a heat sealing process to include an optional encapsulating or serial air bladder, and assembling the liner and outer helmet shell together.

There are many sports that require the use of helmets such as football, baseball, bicycle riding, hockey, motor sports, and the like. All of these helmets differ in their overall appearance and function, but share the common goal of protecting the user's head from impact. Different areas of coverage, padding, internal suspension, and even the materials used all share the common goal of providing impact protection. These same protective properties are also important in helmets used in medical, construction, military, and law enforcement activities as well. Manufacturers and researchers are constantly on the lookout for new materials, applications, and processes to enhance the safety properties of their protective helmets. A persistent problem facing many manufacturers and researchers is developing a helmet that is more conforming to a user's head so as to substantially attenuate, or even obviate, secondary impact without adding significant costs to the production of the helmet. Accordingly, there exists a need for a means by which the protective properties of helmets can be enhanced to further their injury preventing characteristics. The development of the present invention fulfills this need.
The method of manufacture and design of the helmet of the present invention provides for a customization of the helmet, enabling fine tuning, to ensure fabricating a sufficient first shock absorbing layer by avoiding undesirable characteristics of prior art prefabricated helmets. The undesirable characteristics of prior art helmets are a mismatch, leading to the existence of air gaps, between the liner portion of the helmet and the user's cranium shape. In fact, these air gaps can create a secondary impact between the liner and the cranium, resulting in localized high impact loads of the surface areas of contact. The methods and designs of the present invention provide a cost effective method of fabricating helmets with helmet liners that substantially reduce, or obviate, secondary impact occurrences while simultaneously reducing the required thickness of the helmet layers affording impact protection. The custom helmet design of the present invention reduces the need for excessive comfort foam found in prior art helmets. The first shock absorbing layer of the present invention is custom formed to match the wearer's head, where the customization method relies on measuring and mapping the user's head using a variety of digital scanning methods. The same processes are then applied to the interior of the helmet structure. The interior of the helmet shell may also be defined with a three-dimensional CAD model used to build high volume manufacturing tools. Next, using a variety of manufacturing methods such as sculpting, additive/subtractive, machining, or the like, a protective liner is fabricated. When used in a helmet with the respective user, an exact fit is formed, thus preventing any movement of the user's head in a manner that reduces injury upon any impact.
Prior art in this field consists of helmet designs that rely upon excessive cushion layers to provide the requisite protection. Some prior art methods of fabricating such helmet designs are elaborate and costly, and rarely result in proper cranium contour and profile matching, which exacerbates the above-fore-mentioned problems.
It is an objective of the present invention to provide a customization method for a helmet that allows for fine tuning to ensure fabricating a sufficient first shock absorbing layer by avoiding undesirable characteristics such as an excessively sized second outer shell, an excessive offset of the molded liner, an extra thick second impact absorbing layer, an extra thick soft second comfort layer, excessive air contained within bladder portions (if so equipped), and large air gaps between the molded liner and the user's cranium.
It is further objective of the present invention to provide a helmet design and method of fabrication for the customized helmet and helmet liner allows for a customized composite helmet liner that can be incorporated into existing and new helmet designs resulting in significantly enhanced comfort, stability, and shock absorption safety.
It is a further objective of the present invention to afford a user better control of positioning and simpler donning and doffing of the helmet via the use of the custom liner.
It is a further objective of the present invention to provide a helmet design and method of fabrication resulting in low-cost manufacturing comparable to prior art prefabricated helmets due to prefabricated segments stored in bins of the helmet liner of the present invention, which are stored by size, shape, and material.
It is a further objective of the present invention to enable unique helmet designs and a fully customized interface between the helmet liner and the user's cranium, applicable to a wide range of protective helmets, through the use of the disclosed method of fabrication.

Method for customizing and manufacturing a composite helmet liner


A user data management device, a storage medium which stores a control program, and a control method are disclosed which efficiently report the identity of a user who is using equipment to some or all members of the department in which that equipment is located, or to managers of that department, in order to be informed of the use status of that equipment, and control the use of that equipment by unauthorized users. The user data management device includes input means that inputs user data belonging to a user that will use the equipment, notification means that will provide one or more persons with identity data concerning a user who is using the equipment in which the user data was input, authentication means that authenticates the user from the user data, and notification determination means that will determine one or more persons to be provided with identity data, and then provide identity data to them that identifies the user authenticated with the authentication means by means of the notification means.

1. Field of the Invention
The present invention relates to a user data management device, and more particularly to a user data management device that manages the use status of equipment in a department.
In addition, the present invention relates to a storage medium that stores a control program for the user data management device, and a control method that is performed in the user data management device.
2. Background Information
The network printer technology described below is conventionally used to manage a department.
When an operator orders printing to be performed with a network printer, both print data and the name of the operator are transmitted to the printer, and the name of the operator is displayed on a liquid crystal display panel that forms a portion of the printer. When printing is complete, and the printed document is discharged to the discharge tray, the printed document is detected by a printed document sensor provided on the bottom surface of the discharge tray. This will illuminate an LED in order to inform one of the printer's use status. See, for example, Japanese Unexamined Patent Application Publication No. H06-191128.
However, with the aforementioned conventional technology, when an organization is composed of a plurality of departments that are each composed of a plurality of users, and the organization has a system by which a fee is charged to a department each time a user affiliated with that department uses equipment such as a printer or the like, one problem that occurs is when a user knows the user data (e.g., department code) of another department, and thus can avoid incurring a fee by inappropriately using that department code to use the equipment.
In view of the above, there exists a need for a user data management device, storage medium which stores a control program, and control method which overcome the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.

User data management device having a notification determination device that determines who is provided with identity data, storage medium which stores a control program, and control method


A protective door having push switches, access to racking unit and viewing windows is assembled with the electrical device such that the protective door encloses the electrical device with a flame proof sealing. The push switches and cutout to access racking unit are made aligned with the electrical device such that the switches of the electrical device are actuated through the push switches, racking in and out the device is possible through the cutout to access racking unit and it allows reading the rating plate, display of the electrical device through the viewing windows in the protective door even if the protective door is closed. The push switch has a push rod and a spring loaded push button assembled inside a cylinder and the push button is clamped from the front of the protective door. The push switches are arranged such that a reset switch contact with the position reset switch of the electrical device, push switches to respectively switch ON and Switch OFF the electrical device.

Arc flash is a common phenomenon in all the electrical enclosures as switchboards, switchgears, motor control centre, panelboard etc. Arc flash can be described as a short circuit through air that flashes from one live conductor to another conductor or to the ground, in which large amounts of light and waves of heat energy are released explosively from electrical equipment. The amount of heat produced by an arcing event in low and medium energy equipment can be very large. The electric arc produced by these sources can jump anywhere from a few inches to several feet, depending on the voltage level involved.
As electricity travels through body, literally seeking ground, it leaves a path of harm and destruction all along the path it takes inside of body. The high temperature during internal arc evaporates the nearby materials and heats up the surrounding air, which results in an overpressure in the switchgear compartment. Extreme pressure exerts a significant force on the enclosure structure such as frame, door, side panels, rear panels, roofs etc. and often dislodges these parts.
Most of the time the operator become the victim during the course of actions at workplace that involve electrical equipment. Arc flash can cause traumatic injuries. The superheated ball of gas accompanying the flash can cause burns over entire body and lung, even death from these injuries is a real possibility, since the human body is a great conductor of electricity. The hot gases and the transient pressure waves may endanger persons close to the switchgear and may seriously damage the electrical equipment and the building. In a typical arc resistant electrical enclosure, besides the mechanical stress to equipment, the danger to persons close to the electrical enclosure must be excluded. Here, after exceeding a predetermined pressure limit, the hot gases trigger over pressure relief devices and the enclosure structure should withstand the high pressure until it is released completely.
If an operator is working on a circuit breaker and say an arc event takes place then there would be minimum protection to him in the form of a door. The door can deform due to the pressure of arc and the flames and gases may affect the operator. The gases can also come out from the circuit breaker front face, sealing and sides of door. During an arcing event the high temperatures and pressure generated are sufficient enough to burn a Human Being and it also vaporize all materials in the vicinity of the arc.
In order to overcome the arc effects, various approaches have tried to make the existing doors rigid by improving the latches, hinges or by providing the gaskets to existing door to avoid gases coming out. In the above cases, gases and plasma may melt the gaskets or circuit breaker casing which may allow escaping of the gases. Additionally, a high intensity blast may bend the door making the gases escape. Also in all the cases the operator has to rack in or out without any protection as the circuit breaker will be protruding out of the door.
Another approach is tried to provide bellows to cover the circuit breaker. Even in this case the bellows may melt due to a high intensity blast again making it unsafe. Arc flash incidents are common and costly, and the frequency of reported accidents is increasing and the overall safety industry is concerned. The occurrence of arcing inside switchgear has many undesirable effects. The arc energy can cause sudden pressure increase inside the enclosure resulting in severe mechanical and thermal stress on the equipment particularly on doors.
The safety of operators against hot gases, radiation and fragmentation of the enclosure must be secured. The important acceptance criteria must be fulfilled for a successful internal arc test, e.g. correctly secured doors and covers do not open or indicators do not ignite due to the effects of hot gases. It is necessary to protect the operator working on the device from any accidents and also helping in redirecting the arc to proper ventilating paths, thus exhaling the gasses to the intended exhaust.
However, in all the above cases the operator is not completely safe and in all the cases the operator has to ensure that either he wears protective devices or he has to take extra precautions to avoid from the arc during a circuit breaker switching and racking operation. Therefore it is desirable to provide an improved protection system for the circuit breaker which overcomes all the disadvantages of the conventional protection system and to withstand the effects of an internal arcing fault, thereby protecting the operator from the accidents due to arcing effects.

Protective door assembly for electrical devices


A method of preparing (R,S)-nicotine, comprising reacting a nicotinate ester with N-vinyl-2-pyrrolidinone in the presence of a base and a solvent to form a first mixture, combining the first mixture with an acid to form a second mixture comprising an aqueous layer, separating the aqueous layer from second mixture, combining the separated aqueous layer with an acid to form a third mixture, combining the third mixture with a base to form a fourth mixture comprising myosamine, reducing myosamine to nornicotine using a reducing agent, and methylating the nornicotine to yield R,S-nicotine.

Nicotine is currently used as a dilute solution, typically in combination flavor, in liquid in vaporization devises (commonly known as vaporizers), as well as cessation devises such as patches and gums. A salient feature of the state of the art is that essentially all the nicotine employed in these "vaping devises" is nicotine liquor that has been prepared from tobacco, extracted from the tobacco plant usually using kerosene as the solvent, then purified; and such extracts cannot be purified to rid of many of the compounds that are also found in tobacco plant extract. Thus, extremely pure nicotine that is devoid of these contaminants is not, nor has not been commercially available, and may prove to be very difficult to prepare commercially, or even in research quantities. It is important to note that many of these contaminants are unhealthful for the human system, many have been shown to be carcinogenic, and enhance addictive qualities of the "nicotine".
A need for nicotine material that is devoid of these disease causing contaminants exist in today's marketplace.
While several synthetic methods of nicotine preparation are known, the commercialization of synthetic nicotine has not taken place. Known methods of preparing extremely pure synthetic nicotine are prohibitively costly on an industrial scale. See for example, EP 2487172.
Thus, there is a need in the art for a synthesis of nicotine that avoids/minimizes many of the pitfalls of the methods previously reported for the synthetic preparation of nicotine on an industrial scale, thus achieving pure nicotine in commercially viable quantities and with an acceptable cost of manufacturing.

Process for the preparation of (R,S)-nicotine


A method of estimating the height of water (hw) that is present on a wet ground of a road and that is in contact with a tread of a tire of a vehicle travelling on this wet road utilizes one or more sensors in the tread of the tire. Each of the one or more sensors is capable of measuring a characteristic quantity of stresses that the tread experiences locally when the tire is rolling on the ground. A signal corresponding to these measurements is produced, and a portion of this signal relating to a passing of the one or more sensors into an apparent area of contact between the tire and the ground is extracted. An instantaneous value (ΔL), relating to a length of an indirect contact region of the apparent area of contact between the tread of the tire and the ground, is determined from this information, and a water height (hw) is estimated from a calculation that takes into account the determined instantaneous value.

It is in fact useful to be able to estimate a height of water present on a road in real time so as to better appreciate the onset of hydroplaning.
Hydroplaning is characterized by the momentary presence of an amount of water between the ground making up the road and that part of the tire tread in contact with the ground. In this case, the film formed by the presence of water prevents all or some of this contact—there is no longer grip and therefore no longer force transferred between the vehicle and the road.
A film of water forms between all or part of the tire tread in contact with the ground when the flow rate of water flowing between these two surfaces becomes greater than the flow rate of water that the features of the road pavement and that of the tire can remove. This saturation effect is dependent on the height of water present on the ground and the speed of the vehicle.
The consequences of hydroplaning, during an acceleration by application of a driving force, during a deceleration by application of a braking force or during a change in direction, are considerable and can involve a partial or complete loss of control of the vehicle. It is therefore of paramount importance when travelling on a wet surface to be able to anticipate the conditions for hydroplaning.
To the driver of the vehicle, no warning sign precedes the onset of partial or complete hydroplaning—the danger is sudden and cannot be foreseen.
In addition, the water height measurement is information that can be taken into account by the various electronic assistance devices used, for example, for controlling an antilock braking system (ABS) of the vehicle, antiskid regulation (ASR) of the driving wheels, and trajectory control (ESP) or other forms of control or monitoring, such as for example the monitoring of tire pressure. Such information, coupled for example with a measurement of tire grip, would enable the effectiveness of these devices to be greatly improved in real time.
It is known from U.S. Pat. No. 5,502,433 to detect hydroplaning, but no mention is made of taking into account or estimating the height of water on the ground of the road. That patent merely involves observing a hydroplaning phenomenon beneath the tire, without providing a way to quantify it or even to determine one of the parameters of the origin of this phenomenon.

Method of estimating a height of water in contact with a tire on a road


A piezoelectric filter in which an earth electrode is provided in the center of a piezoelectric substrate in the direction of thickness; an input electrode is provided on the upper surface of the piezoelectric substrate so as to be opposed to one part of the earth electrode; an output substrate is provided on the lower surface of the piezoelectric substrate so as to be opposed to another part of the earth electrode except the aforementioned one part; a first dummy electrode is formed on the upper surface of the piezoelectric substrate so as to be opposed to the output electrode through the piezoelectric substrate; and a second dummy electrode is formed on the lower surface of the piezoelectric substrate so as to be opposed to the input electrode through the piezoelectric substrate.

1. Field of the Invention
The present invention relates to a piezoelectric filter of an energy-trapped type using a second harmonic wave of the thickness-extensional vibration mode.
2. Description of Related Art
FIGS. 8 and 9 show a conventional piezoelectric filter of an energy-trapped type using a second harmonic wave of the thickness-extensional vibration mode.
As shown in FIG. 8, in a piezoelectric filter 1, an earth electrode 3 is arranged in the center, in the direction of thickness, of a piezoelectric substrate 2, which is polarized in the direction of thickness as indicated by the arrows. On the upper surface 2a of piezoelectric substrate 2, an input electrode 4 is formed so as to be opposed to a part of the earth electrode 3 through a piezoelectric substrate layer. On the other hand, an output electrode 5 is formed on the lower surface 2b of piezoelectric substrate 2. The output electrode 5 is formed so as to be opposed to the other part of the earth electrode 3 through a piezoelectric substrate layer, and is positioned so as not to overlap with the input electrode 4 through the piezoelectric substrate 2.
FIG. 9 is an exploded perspective view showing plane shapes and relative locational positions of the aforementioned earth electrode 3, input electrode 4, and output electrode 5. In FIG. 9, the output electrode 5 is shown by the lower surface 2b of the piezoelectric being projected below.
The aforementioned conventional piezoelectric filter 1 is a double-mode filter using a second harmonic wave of the thickness-extensional vibration mode and is intended to be used in a high-frequency region.
Although the piezoelectric filter 1 provides the energy-trapped type of piezoelectric filter operable in a high-frequency region, its insertion loss is relatively large and, therefore, a reduction of such insertion loss is desirable.
Furthermore, in the aforementioned piezoelectric filter 1, a reduction of matching impedance also has been desired so that the piezoelectric filter has application to wider uses. In order to reduce the matching impedance, it has been considered to increase the area of the electrodes in the piezoelectric filter 1, that is, the area of the earth electrode 3 and the input and the output electrodes 4 and 5. However, an increase in the electrode area leads to the reduction of matching impedance, accompanied by a problem of deterioration of the characteristics, which is caused by the enhancement of the level of unwanted spurious vibration.


This invention relates to fertilizer and herbicide compositions. The present invention provides a composition for selective fertilization of a transgenic plant comprising a polypeptide which metabolizes a D-amino acid substrate; said composition comprising said D-amino acid substrate. Another aspect of the present invention provides a selective herbicide composition comprising a D-amino acid. Such a herbicide will inhibit or reduce the growth of plants which do not contain the appropriate D-amino acid metabolizing enzyme, while the growth of transgenic plants which are able to metabolize the D-amino acid will be unaffected or, more preferably, be increased or enhanced. Methods and means are also provided for selectively modulating the growth and stress tolerance such plants using D-amino acids. The methods can be used either for detoxification of phytotoxic D-amino acids such as D-alanine and D-serine, thereby allowing for selection of plants comprising said D-amino acid metabolizing enzymes, or for enhancing toxicity of lesser phytotoxic D-amino acids such as D-isoleucine, thereby allowing for selection of plants not comprising said D-amino acid metabolizing enzymes.

Nitrogen is needed in large amounts by plants as a mineral nutrient. Plant growth, particularly in agriculture, is often limited by the amount of available nitrogen.
Traditionally, plants have been considered to use only ammonium and/or nitrate as sources of nitrogen. These compounds are supplied either by natural processes, such as the mineralisation of organic nitrogen and nitrogen fixation by symbiotic prokaryotes, or by the application of fertilisers containing industrially fixed nitrogen.
However, recent research has indicated that plants may also have access to certain organic nitrogen compounds, as well as inorganic nitrogen (Näsholm, T. et al. (1998) Nature 392, 914-916, Näsholm, T. et al (2000) Ecology 81: 1155-1161, Näsholm, T. and Persson, J. (2001) Physiol Plant 111: 419-426, Lipson, D. and Näsholm, T. (2001) Oecologia 128: 305-316). In particular, the uptake and metabolism of amino acids from soil seems to be a ubiquitous feature of plants.
Among the amino acids used as building blocks for proteins, all but one (glycine) can be found in two isomeric forms which are distinguished by their ability to rotate polarised light. The form found in largest quantities in nature rotates light to the left and is termed L- or levorotatory, while the less common form is termed D- or dextrorotatory.
Whilst D-amino acids are found in nature, they are present only at very low concentrations and only in specific compounds as cell wall proteins in bacteria (e.g. in the compound peptidoglucan).
Although plant amino acid transporters mediate transport of both D- and L-forms of amino acids (Soldal, T. and Nissen, P. (1978) Physiol. Plant. 43: 181-188, Boorer, K. J. et al. 1996. J. Biol. Chem 271: 2213-2220, Montamat et al (1999) Plant Mol. Biol. 41: 259-268), plants lack the necessary enzymes to convert D-amino acids into nitrogen forms that can be used in synthetic reactions inside the plant. Plants cannot therefore use D-amino acids as a source of nitrogen.
The capacity to metabolise D-amino acids is, however, widespread among bacteria, fungi and animals. Several reactions have been described, leading to catabolism of D-amino acids in organisms (see FIG. 2) (Friedman, M (1999) J. Agric. Food Chem. 47: 3457-3479, Pilone, M. S. (2000) CMLS 57: 1732-1747, Yurimoto et al. (2000) Yeast 16(13): 1217-1227).

This patent is subject to a terminal disclaimer.


A telecommunication network without a network management layer meets operational objectives by providing at least one hot standby system which replaces a malfunctioning element of a service-providing node in the event of any disruption in services. Each service-providing node includes n primary processors and k spare processors. The telecommunications network implements all layers of the Telecommunication Management Network (TMN) standard except for the network management layer. The system therefore implements the business managemen, service management, and element management layers. An operation administration and maintenance server monitors the network to detect a malfunctioning element of a service-providing network node. Upon detecting a fault, the operation administration and maintenance server sends an out of service message to a central network planning and operations center and/or notifies an on site work force of the probable trouble. While the failure is being repaired, a hot standby system takes over the function of the defective system.

This invention relates to network management, and more particularly to communications management in a multi-vendor environment, enabling interoperability, simplifying operations, and supporting abstraction of functions provided by network elements. For purposes of illustration, the invention will be described using the Telecommunications Management Network (TMN) framework as a reference model. TMN standards are being developed by International Telecommunications Union (ITU). It will be understood, however, that the invention is equally applicable to other non-TMN compliant networks as well.
Over the past two decades, network elements essentially used proprietary technology which was very expensive and complex due to the fact that it was hardware and software fault-tolerant. Various network management functions such as traffic management, maintenance, configuration management, and routing management were performed by experienced technicians making network management very labor intensive. Moreover, adding a new service or network element required planning, design, engineering, development, and deployment by a team of engineers for 2-3 years, adding to unit cost as well as time to market.
There has been a significant improvement in technology in recent years. The price-to-performance ratio of computing technology, when compared to 1980's technology, has improved by a factor of 100 in the 1990's, and is expected to increase by a factor of 1000 in the next decade. Significant improvement in microprocessor technology, memory chip technology, and application of Very Large Scale Integration (VLSI) has resulted in significant improvement in reliability, availability, processing power, and memory capacity. As a result, proprietary technology is progressively being replaced by commercial off-the-shelf technology. Network elements based on these technologies and application of n+k spare techniques can achieve availability and reliability comparable to fault-tolerant network elements. Also, the current technology can thus be maintained by vendor-supplied technicians instead of a team of experienced technicians previously hired by the service providers for maintaining proprietary technology, leading to further cost savings.
Accordingly, it is not necessary to develop and maintain Network Management Layers, associated interfaces, and core Work Centers (WC's) for network management. It would be more cost effective to have one or more hot standby service processing systems which will take over the failed service processing system. The present invention simplifies resolution of Out Of Service (OOS) conditions by replacing one or more defective boards, or reloading the software or the data bases in the event of receiving an OOS message from Operation Administration and Maintenance Server. It thus follows that there is no need for a complex infrastructure, resulting in significant unit cost improvement.
In view of the foregoing, it is an object of this invention to provide a simplified Telecommunications Management Network (TMN) framework which provides a framework of communications management in a multi-vendor environment, improves and simplifies operations, supports abstraction of functions provided by network elements, and reduces unit cost.
It is another object of this invention to provide a framework of communications management in a multi-vendor environment that improves and simplifies operations, supports abstraction of functions provided by network elements, and reduces unit cost by eliminating the Network Management Layer and its associated Telecommunications Management Network interfaces (TMN I/F).
It is still another object of this invention to provide a framework of communications management in a multi-vendor environment that improves and simplifies operations, supports abstraction of functions provided by network elements, and reduces unit cost by eliminating network management core Work Centers (WC's) managing real-time operations in conjunction with Network Management Layer Operations Support Systems (OSS's).
It is yet another object of this invention to provide a framework of communications management in a multi-vendor environment that improves and simplifies operations, supports abstraction of functions provided by network elements, and reduces unit cost by expanding the role of the Network Planning and Engineering Systems to that of a Central Network Planning and Operations Center, such that it performs critical functions of maintaining r hot standby service processing systems on an ongoing basis, where r is greater than or equal to one.

Telecommunications network devoid of a distinct network management layer


A vibratory mechanism includes vibratory shafts, which are stored within a roll and are arranged symmetrically across a rotation axis of the roll, fixed eccentric weights fixed to respective vibratory shafts, rotatable eccentric weights rotatably attached to respective vibratory shafts, a rotation controller controlling a range of movement of the rotatable eccentric weights, and an eccentric moment controller which changes an eccentric moment around the vibratory shaft depending on the rotation direction of the vibratory shafts, whereby the vibration state of the roll is switchable between standard vibration and horizontal vibration.

1. Field of the Invention
The present invention relates to a vibratory mechanism and a vibratory roller.
2. Description of the Relevant Art
A vibratory roller is mainly used for a compaction of an embankment in a construction site, such as a highway or a dam, or an asphalt pavement of a road.
The compaction using the vibratory roller is performed while vibrating a vibratory roll (roll). Thus, the ground to be compacted is densified in a very dense state. As an example of a vibratory mechanism that is provided within the vibratory roll and causes a vibration of the vibratory roll, the mechanism that causes vibration by rotating a vibratory shaft provided with an eccentric weight has been known.
Here, as an example of a vibration state of vibratory roll, two types of vibration state have been known. One is "standard vibration" which is a vibration that the vibratory roll vibrates in all radial directions thereof. The other is "horizontal vibration", which is the vibration that the vibratory roll vibrates in the direction tangential to the circumference of the vibratory roll.
In the mechanism disclosed in U.S. Pat. No. 4,647,247, is a switching unit, by which the vibration state of the vibratory roll is changed to/from the standard vibration from/to the horizontal vibration.
In FIGS. 10A and 10B of U.S. Pat. No. 4,647,247, a total of two vibratory shafts are provided within the vibratory roll. One of the vibratory shafts is provided at an opposite position across the center of the vibratory roll with respect to the other vibratory shaft. Each of the vibratory shafts is provided with an eccentric weight, and the eccentric weight of at least one of the vibratory shafts is rotatably attached to the vibratory shaft.
In this U.S. patent, if the relative phase angle between eccentric weights in case of rotation in one direction of the vibratory shaft is denoted by 0°, the relative phase angle between the eccentric weights in case of rotation in the other direction of the vibratory shaft is 180°.
When vibrating the vibratory roll under standard vibration or horizontal vibration, the vibratory roll should be vibrated at the suitable amplitude for respective vibration states.
FIG. 4 is an explanatory view showing the vibration of a vibratory roll equipped with a pair of vibratory shafts in case of standard vibration.
In this vibratory roll, an eccentric weight of the same shape is provided to respective vibratory shafts, which are rotated in accordance with a rotational torque supplied from a power supply mechanism (not shown). Thus, respective eccentric weights are rotated in the same direction at the same angular position.
In this occasion, the vibratory force directed away from the center of the vibratory roll is caused, and the direction thereof changes sequentially according to the angular position of eccentric weights. Here, if it is focused on the element vertical to a ground from among all elements of the vibratory force, and the vibratory force thereof is denoted by F, the vibratory force F is indicated by a following formula.F=2·m·r·ω2·sinωt where
m is a mass of an eccentric weight
r is a distance between the center of the vibratory shaft and the center of gravity of the eccentric weight
ω is an angular velocity of vibratory shaft.
Here, m·r is defined as eccentric moment (hereinafter m·r is indicated as "mr").
Thus, a ground can be indicated as a model of spring, which has a predetermined spring constant K and which acts in a perpendicular direction with respect to the contact surface between the vibratory roll and a ground.
When vibratory force F is periodically working on the vibratory roll whose mass is M0, if spring constant K is regarded as a negligibly small value by assuming that a ground is quite loose, the equation of motion is shown by a following formula.2·mr·ω2·sin ωt=M0·d2y/dt2 where
y is a displacement in ups-and-downs directions.
Then, the following formula is obtained from this formula.y=(−2·mr/M0)·sin ωt
Thus, the amplitude a1 in the ups-and-downs directions of the vibratory roll in case of standard vibration can be shown by a following formula (1).a1=2·mr(standard vibration)/M0  (1)
In this formula, "mr (standard vibration)" means that the eccentric moment in case of standard vibration.
FIG. 5 is an explanatory view showing the vibration of a vibratory roll equipped with a pair of vibratory shafts in case of horizontal vibration.
A vibration proof rubber provided between the vibratory roll and a frame (not shown) of the vibratory roller can be indicated as a model of a spring, which has a predetermined spring constant K1 and which acts in a horizontal direction with respect to a shaft center O′ of the vibratory roll.
A ground can be indicated as a model of a spring, which has a predetermined spring constant K2 and which acts in a horizontal direction with respect to the contact surface between the vibratory roll and a ground.
When a periodic torque T is acting on a moment of inertia I around the shaft center O′ of the vibratory roll, which is supported by the spring of spring constant K1 and the spring of spring constant K2, the equation of motion of this case is as follows.p·2·mr·ω2·sin ωt=I·d2θ/dt2 where
p is a distance between the shaft center O′ of the vibratory roll and the center of the vibratory shaft.
Here, respective spring constant K1 and K2 are regarded as a negligibly small values by assuming respective springs are quite loose.
If the radius of the vibratory roll is denoted by R, a displacement y in a horizontal direction with respect to the contact surface between the vibratory roll and a ground can be indicated as y=R·θ, on regarding θ as a slight angular displacement. Thus, a following formula can be obtained.p·2·mr·ω2·sin ωt=(I/R)·d2y/d t2
Then, by performing a formula translation based on y, a following formula is obtained from this formula.y=−((R·p·2·mr)/I)·sin ωt
Thus, the amplitude a2 in a horizontal direction with respect to the contact surface between the vibratory roll and a ground in case of horizontal vibration can be shown by a following formula.a2=R·2·p·mr(horizontal vibration)/I  (2)
In this formula (2), "mr (horizontal vibration)" means that the eccentric moment in case of horizontal vibration.
Here, a mass M0 of a vibratory roll, a radius R of the vibratory roll, and a moment of inertia I around the shaft center O′ of the vibratory roll are determined depending on a dimension of the vibratory roll. Therefore, it is required that the eccentric moment mr (standard vibration) can be determined freely for controlling the amplitude a1 in case of standard vibration to the desired value.
Additionally, it is required that at least one of the distance p and the eccentric moment mr (horizontal vibration) can be determined freely for controlling the amplitude a2 in case of horizontal vibration to the desired value. Here, the distance p is a distance between the shaft center O′ of the vibratory roll and the center of the vibratory shaft.
In the vibratory roll, however, since the vibratory shaft is provided within the vibratory roll, there is a limitation of the distance p (see FIG. 5). Thus, the eccentric moment mr (horizontal vibration) has a great influence on the amplitude a2 in case of horizontal vibration.
Therefore, it is preferable that the eccentric moment in case of standard vibration is different from the eccentric moment in case of horizontal vibration, for establishing the amplitude a1 of standard vibration and the amplitude a2 of horizontal vibration at respective suitable values.
In U.S. Pat. No. 4,647,247, as described above, a total of two vibratory shafts, each of which is provided with an eccentric weight, are stored within the vibratory roll, and the eccentric weight of one of the vibratory shafts is rotatably attached to the vibratory shaft. Therefore, the angular position between eccentric weights varies depending on the rotation direction of the vibratory shaft, but the eccentric moment in case of standard vibration is the same as the eccentric moment in case of horizontal vibration. Therefore, it has been difficult to control the amplitude of the eccentric moment to respective suitable amplitudes for the standard vibration and the horizontal vibration.
Therefore, the vibratory roller that can control the amplitude of the vibratory roll to the desired value for the standard vibration or the desired value of the horizontal vibration has been required.

Vibratory mechanism and vibratory roller


A mobile communication device includes power supply control switches corresponding to a local oscillator, transmitting frequency converter, receiving frequency converter, receiving amplifiers and transmitting power amplifier in a radio unit, and a battery saving control circuit in a control unit. By individually controlling the ON timing of the switches by means of the battery saving control circuit, it is possible, prior to a time slot period allocated to an individual mobile station, first to supply power to the local oscillator, then supply power to the frequency converters, and then supply power to amplifiers. By doing so the mobile communication device is set in a standby state for transmitting/receiving operation.

The present invention relates to a mobile communication device for use in a system connected by a TDMA scheme between a base station and a plurality of mobile stations, such as a digital cordless telephone system and a celluler communication system.
In recent years, various mobile communication systems have been developed with an advance in the communications technique and a growing need for communications. As one of them there is a digital cordless telephone system called a PCS (personal communication system).
This type of system comprises, as shown in FIG. 8 for instance, a plurality of base stations CS1, CS2, CS3, . . . connected via wire telephone lines to the public switched telephone network NW and a plurality of mobile stations PS1, PS2, . . . connected via radio channels to these basic stations CS1, CS2, CS3, . . . The respective mobile stations PS1, PS2, . . . make their mutual communication via the corresponding base stations or relative to the corresponding subscriber terminal connected to the public switched telephone network NW.
Here, a 4 channel TDMA (time division multiple access)--TDD (time division duplex) scheme is adopted as a radio access scheme between the base stations CS1, CS2, CS3, . . . and the mobile stations PS1, PS2, . . .
The radio access scheme has a transmission signal frame, that is, a signal frame transmitted on a plurality of radio carriers f1 to fm, comprised of four time slots FL1 to FL4 for forward link used for communication from the respective mobile station to the corresponding base station and four time slots RL1 to RL4 for reverse link from the base station to the corresponding mobile station, as shown in FIG. 9 for instance. The radio communication is done between the mobile station and the base station by allocating, as information channel to the mobile stations, a pair of each of time slots FL1 to FL4 for forward link and a corresponding one of time slots RL1 to RL4 for reverse link. That is, the four information channels are provided for each radio carrier.
In the mobile communication device adopting this type of radio access scheme, an important task is how long the life of a battery unit has to be extended. In order to realize this task, various types of battery saving schemes have thus far been proposed. Some saving scheme is adopted to suppress any unnecessary power consumption by cutting off a power supply from the battery unit to a radio unit in other than those time slots of the information channel allocated to an individual mobile station for instance. This type of conventional system will be set out below.
FIG. 10 is a view showing an arrangement of a radio unit of a mobile communication device adopting this battery saving scheme. In FIG. 10, an operation voltage of a control unit 50 is supplied through a switch SW6 to a local oscillator 14. Further, the operation voltage of a power source unit is supplied via a switch SW7 to a frequency converter 151 and transmission power amplifier 152 in a transmitting circuit. On the other hand, the operation voltage from the power source unit is supplied via a switch SW8 to a frequency converter 131 and amplifiers 132 and 133 in a receiving circuit.
The respective switches SW6, SW7, and SW8 are ON-OFF controlled by corresponding switch control signals output from the control unit 50.
In such arrangement, at a transmission period, the switch SW6 is first turned ON at a time point a predetermined time T1 earlier than a start time point of a transmitting time slot, while giving consideration to a delay rise of the local oscillator 14. For this reason, an operation voltage is supplied from the power source unit to the local oscillator 14 where an oscillation operation is started. Then a switch SW7 is turned ON at a time point a predetermined time T2 earlier than a start time point of the transmitting time slot. For this reason, an operation voltage is supplied from the power source unit to the frequency converter 151 and transmission power amplifier 152 in the transmitting circuit. By doing so, the frequency converter 151 and transmission power amplifier 152 in the transmitting circuit become operative. In this connection it is to be noted that the time T2 is set in accordance with a time taken for a variation in oscillation frequency occurring in the local oscillator 14 at a start time of the frequency converter 151 to converge.
At the period of transmitting time slot, a modulated signal output form a modulation circuit, not shown, is input to the frequency converter 151. In the frequency converter 151, the modulated signal is mixed with the local oscillation signal generated from the local oscillator 14 and is frequency-converted to a signal for a radio carrier. The transmission radio carrier signal, after being amplified by the transmission power amplifier 152 to a predetermined transmitting power level, is transmitted from an antenna, not shown, to the base station.
When the period of transmission time slot is ended, the switch control signal is output from the control unit 50 and the switches SW6 and SW7 are turned OFF. For this reason, the supply of a power from the power source unit to the local oscillator 14 and transmitting circuit is stopped, so that the transmitting system is set in a battery saving state.
At a receiving time, on the other hand, as shown for example in FIG. 12, the switch SW6 is first turned ON a predetermined time T1 earlier than the start time point of the receiving time slot as in the case of the transmitting time. For this reason, an operation voltage is supplied from the power source unit to the local oscillator 14, so that the local oscillator 14 starts its oscillation operation. Then the switch SW8 is turned ON at a time point a predetermined time T3 earlier than the receiving time slot starting time. For this reason, the operation voltage is supplied from the power source unit to the frequency converter 131 and amplifiers 132, 133, so that the frequency converter 131 and amplifiers 132 and 133 are set in an operative state. The time T3, like the time T2, is set in accordance with a time taken for a variation in the oscillation frequency occurring in the local oscillation circuit 14 at a start time of the frequency converter 131 to converge.
When, in this state, the receiving time slot period is entered and the radio carrier signal directed to the corresponding individual mobile station is received by the antenna, not shown, the radio carrier signal, after being amplified by the high frequency amplifier 132, is input to the frequency converter 131. In the frequency converter 131, the radio carrier signal is mixed with the local oscillation signal generated from the local oscillator 14 and frequency-converted to a reception signal of an intermediate frequency or baseband frequency. The reception signal, being amplified by the amplifier 133, to a demodulation circuit, not shown, where it is demodulated.
When the receiving time slot period is ended, the switches SW6, SW8 are turned OFF by the control of the control unit 50 and hence the supply of electric power to the local oscillator 14 and receiving circuit is cut off, so that the receiving system is set in a battery saving state.
That is, in the arrangement above, the respective circuits of the receiving and transmitting systems receive power supply only during the receiving and transmitting time slots and are made in an operative state. And during the other idle period, these circuits are placed in a not-operated state. For this reason, the dissipation power of the mobile station is reduced in comparison with the case where the power is constantly supplied to the respective circuit of the receiving and transmitting systems. By doing so, it is possible to extend the life of the battery unit.
However, the above-mentioned conventional circuit has the following tasks to be solved. That is, the timing of the power supply to the frequency converter is so set as to be adequately earlier than the start time points of the receiving and transmitting time slots, taking into consideration the time taken for a variation in the oscillation frequency in the local oscillator at a start of the frequency converter to converge as set out above. The start times of the respective amplifiers are normally very shorter than the time at which the frequency variation of the local oscillator converges.
Either in the receiving circuit or in the transmitting circuit, the conventional circuit simultaneously control the power supply to the frequency converter and respective amplifiers. In the respective amplifiers, therefore, from the setting of their operative state by the power supply to the starting of their actual signal amplification operation following the reaching of the receiving time slot or transmitting time slot, there occurs an unnecessary power dissipation over a relatively long period of time. Since the transmission power amplifier 152 consumes more power than the remaining circuits, it adversely affects the life of the battery unit, thus offering a bar to effectively achieve an effective battery saving.

TDMA mobile communication device for reducing a power consumption and method


The invention relates to a method and to an arrangement for demodulating a signal (f) preferably frequency modulated with digital information, and then particularly a frequency shift modulated signal, with a frequency counter detector (16) which directly produces a digital value representative of the instantaneous frequency of the frequency modulated signal. In order to obtain the lowest possible uncertainty in frequency detection at unchanged counter frequencies (f.sub.r), the frequency modulated signal is mixed down to a difference frequency (f.sub.3) which is insignificantly higher than the sampling frequency (f.sub.s) required to extract the modulation information from the instantaneous counter value (N.sub.2) The frequency counter detector begins a counting sequence during each of the periods of the difference frequency.

In certain kinds of data communication systems using radio links, it is usual to use frequency-shift modulation in signal modulating processes. This enables standard components to be used to a large extent on the receiver side, for instance in the final stage of the intermediate frequency part and in the FM detector. The intermediate frequency amplifier will then consist of an amplitude limiting amplifier which delivers an MF signal of constant amplitude and of the square-wave type. The most common type of detector is of the analogue type, for instance, a quotient detector which produces an analogue detected signal. In the majority of mobile radio systems, digital signal processing is used to detect and to correct errors. It is known to use an A/D-converter connected to the output of the FM-detector in order to obtain a digital signal for signal processing purposes. In the case of a mobile data communication system, for instance, of the MOBITEX type (registered trademark), problems occur with regard to detector temperature drift and detector zero point errors.
It is known, for instance in U.S. Pat. No. 3,548,328, U.S. Pat. No. 3,600,680, U.S. Pat. No. 3,670,250, U.S. Pat. No. 4,236,110 or U.S. Pat. No. 4,409,984 to determine in an FM receiver and a frequency meter the frequency of a square wave of frequency f with the aid of a digital period counter which is clocked with a reference oscillator with a high degree of accuracy. The reference oscillator having frequency f.sub.r feeds a counter which counts-in reference pulses f.sub.r over a maximum measuring time T. The maximum measuring time T is determined by the information theoretical consideration (the sampling theorem). In the studied system, the requisite sampling frequency is 32 kHz, which gives a maximum measuring time of 1/32.10.sup.-3s.
When the center frequency of the FM signal is f.sub.nom, it is possible to count in approximately f.sub.nom T periods of the signal f during the measuring time T. If a fixed number of N.sub.1 =f.T periods of the current intermediate frequency f is now allowed to gate reference frequency pulse forwards to the counter, the counter will counting N.sub.2 periods of the reference frequency f.sub.r. The period time for N.sub.1 periods of f can then be determined with a normal counter uncertainty of .+-.1 period of the reference frequency f.sub.r. The number of pulses is a non-linear function of the detected frequency and therefore requires a linearising operation in order for the output signal to be a linear function of the frequency. Such a conversion can be effected, for instance, through the use of tables or with the aid of an appropriate arithmetical operation, in a manner known per se. Similarly, the modulation frequency can be obtained through the use of a simple, known operation.
The error in the time period will be EQU .epsilon.=.+-.1/f.sub.r.1/N.sub.1 =.+-.1/f.sub.r.1/f.sub.nom.1/T and the relative error will be .epsilon.=.+-.1/f.sub.r.T (1)
According to one current example, in which the reference frequency obtained from a clock generator common to the unit, f.sub.r was equal to 12.8.10.sup.6 Hz and T was equal to 10.sup.-3 /32 s.
This gave a relative error of .epsilon..sub.r =2.5.10.sup.-3. Consequently, at an intermediate frequency of 450.10.sup.3 Hz the uncertainty in the determination of the frequency f is EQU .epsilon.=450.10.sup.220.127.116.11.sup.-3 ( 2)
Consequently, it is scarcely possible to determine the frequency with an accuracy greater than .+-.1125 Hz when using purely digital methods at the intermediate frequency of 450 kHz normally used.

Method and arrangement for demodulating a frequency modulated signal


A dead cable end distributes holding force over a length of a cable end to reduce or eliminate damage to cables. The dead cable end includes a housing containing a plurality of collets each residing in a collet receptacle. Each collet includes a conical exterior and a lengthwise collet gap and each collet receptacle includes a conical interior. The collets and collet receptacle are held inside the housing by a retaining nut, and the collet and collet receptacle pairs are compressed between the retaining nut and a spring inside the housing. The cable end resides inside the collets, and compressive force on each collet and collet receptacle pair causes each collet to compress radially and hold the cable end. The holding force is thereby distributed over the length of each collet and over the plurality of collet and receptacle pairs to avoid damage to the cable.

The present invention relates to securing the ends of cables and in particular to force distributing ends for securing the ends of cables.
Light weight cables have been developed which replace heavy steel cores with light weight cores, such as a carbon fiber core with a fiberglass sheath. Such light weight cores may be damaged by cable ends which concentrate holding forces over a small area of the cable surface.


A disclosed antenna apparatus includes a base made of a dielectric material; an antenna element pattern formed on a surface of the base; a ground pattern formed in a position adjacent to and opposite to the antenna element pattern on the same surface of the base; and a surface-mounted coaxial connector mounted on the ground pattern in a position close to a feeding point of the antenna element pattern.

1. Field of the Invention
The present invention generally relates to an antenna apparatus, and more particularly relates to a planar antenna apparatus using UltraWideBand (UWB).
2. Description of the Related Art
In recent years, wireless communication technologies using UltraWideBand (UWB) have gotten a lot of attention because of UWB's wide range of applications such as radar positioning and high capacity transmission. In 2002, the Federal Communications Commission (FCC) of the United States approved the use of UWB in the frequency band between 3.1 and 10.6 GHz.
UWB is a transmission system using ultrawideband signals for communication. An antenna used for UWB must be capable of sending/receiving ultrawideband signals.
An antenna, which is composed of a base board and a power feeder, for use in the frequency band between 3.1 and 10.6 GHz approved by FCC has been proposed (non-patent document 1).
FIGS. 1A and 1B are perspective views of exemplary conventional antenna apparatuses. An antenna apparatus 10 shown in FIG. 1A has a structure where a power feeder 12 shaped like an inverted cone is placed on a base board 11. The side surface of the cone-shaped power feeder 12 forms an angle θ with the axis of the antenna apparatus 10. The angle θ provides characteristic features of the antenna apparatus 10.
An antenna apparatus 20 shown in FIG. 1B has a structure where a teardrop-shaped power feeder 22 composed of an inverted cone 22a and a sphere 22b is placed on a base board 11. The sphere 22b is in contact with the internal surface of the inverted cone 22a.
[Non-patent document 1] 2003 IEICE (The Institute of Electronics, Information and Communication Engineers) General Conference, Mar. 22, 2003, Room B201, B-1-133: An Omnidirectional and Low-VSWR Antenna for the FCC-Approved UWB Frequency Band, Takuya Taniguchi and Takehiko Kobayashi (Tokyo Denki University)
[Patent document 1] Japanese Patent Application Publication No. 2000-196327
As described above, a conventional wide-band antenna apparatus normally has a structure where a cone-shaped or teardrop-shaped power feeder is placed on a base board. Because of this structure, a conventional wide-band antenna apparatus is normally large in size, and therefore there has been demand for a more compact and thinner antenna apparatus.
FIGS. 2A and 2B are perspective views of a planar UWB antenna apparatus 30 disclosed in the specifications and drawings of Japanese Patent Application No. 2006-91602 filed by the same applicant. The planar UWB antenna apparatus 30 is a compact and thin antenna apparatus. The planar UWB antenna apparatus 30 includes an antenna element pattern 32, a stripline 33, and two ground patterns 34 and 35 formed on an upper surface 31a of a base 31 made of a dielectric material. Also, a coaxial connector 50 is mounted on an edge of the base 31.
The ground patterns 34 and 35 form ground potential regions near the antenna element pattern 32 and thereby generate lines of electric force around the antenna element pattern 32. Also, the ground patterns 34 and 35 constitute a part of a microwave transmission line 40 of a Coplanar waveguide type.
The stripline 33, the ground patterns 34 and 35, and the base 31 form the microwave transmission line 40 of a Coplanar waveguide type. The coaxial connector 40 is soldered onto the stripline 33 and the ground patterns 34 and 35 at the end of the microwave transmission line 40 of a Coplanar waveguide type extending from the antenna element pattern 32.
The planar UWB antenna apparatus 30 is used in the frequency band between 3 and 6 GHz.
The line Ia in FIG. 6 shows VSWR (voltage standing wave ratio) vs. frequency characteristics of the planar UWB antenna apparatus 30. A preferable value of VSWR is 1.4 or lower. However, as indicated by the line Ia in FIG. 6, the VSWR of the planar UWB antenna apparatus 30 is higher than 3.0 around 3 GHz, and therefore there is demand for improvement.


A gimbal for supporting a slider at its leading surface in a disc drive assembly includes a gimbal body, a slider support beam and a slider mounting tab. The slider support beam is carried by the gimbal body and defines a vertical slider alignment feature. The slider mounting tab extends out of plane from the slider support beam and defines a horizontal slider alignment feature. The slider mounting tab is attached to the leading surface of the slider. The design of the slider mounting tab of the present invention is useful for supporting a leading edge microactuator at a leading edge of the slider for micropositioning a transducer over ideal track centers on a disc surface.

The present invention relates to a disc drive storage system. In particular, the present invention relates to an improved gimbal suspension which supports a disc head slider at its leading edge.
Disc drives of the "Winchester" type are well known in the industry. Such drives use rigid discs coated with a magnetizable medium for storage of digital information in a plurality of circular, concentric data tracks. The discs are mounted on a spindle motor which causes the discs to spin and the surfaces of the discs to pass under respective hydrodynamic (e.g. air) bearing disc head sliders. The sliders carry transducers which write information to and read information from the disc surfaces.
An actuator mechanism moves the sliders from track to track across the surfaces of the discs under control of electronic circuitry. The actuator mechanism includes a track accessing arm and a suspension for each head gimbal assembly. The suspension includes a load beam and a gimbal. The load beam provides a preload force which forces the slider toward the disc surface. The gimbal is positioned between the slider and the load beam, or is integrated in the load beam, to provide a resilient connection that allows the slider to pitch and roll while following the topography of the disc. It is important that the gimbal be designed to withstand and distribute flexure forces so that the suspension system does not fail due to fatigue.
The slider includes an air bearing surface which faces the disc surface. As the disc rotates, the disc drags air under the slider along the air bearing surfaces in a direction approximately parallel to the tangential velocity of the disc. As the air passes beneath the air bearing surface, skin friction on the air bearing surface causes the air pressure between the disc and the air bearing surface to increase which creates a hydrodynamic lifting force that causes the slider to lift and fly above the disc surface. The preload force supplied by the load beam counteracts the hydrodynamic lifting force. The preload force and the hydrodynamic lifting force reach an equilibrium based upon the hydrodynamic properties of the slider and the speed of rotation of the disc.
The slider preferably flies with a positive pitch in which the leading edge of the slider flies at a greater distance from the disc surface than the trailing edge. This ensures that the transducer, which is typically carried at the trailing edge, remains close to the disc surface and provides a stable fly height profile across the disc surface. Tolerance variations during attachment of the slider to the gimbal relative to the location of the preload force can alter the pitch angle of the slider as well as the alignment characteristics of the slider. It is desirable to provide a gimbal which facilitates the attachment of a slider to the gimbal to produce a head gimbal assembly having the desired pitch characteristics as well as alignment characteristics.
In addition, accurate positioning of the transducer relative to the data tracks is important for accurate, reliable recording. As the track spacing or track "pitch" continues to decrease in modern disc drives, it becomes increasingly difficult for traditional actuators to accurately position a transducer over the ideal center of a desired data track. As a result, microactuation devices have been proposed to improve the ability of the actuator system to finely position a transducer over the ideal track center.
Another difficulty in positioning the transducer arises with the use of magnetoresistive ("MR") heads. In an MR head, there is an offset between the active magnetic centers of the read transducer and write transducer on a single MR head. Because of mask misalignment during manufacture, the read and write transducers can be spatially separated from one another to a greater or lesser degree than otherwise desired. Thus, when the MR head is finally positioned over a track during a write operation, that same position is not the ideal track center for the MR head during the read operation. Since the read transducer is spatially separated from the write transducer, the MR head must be radially moved within the track, or repositioned within the track, so that the read transducer position is over the ideal track center.
The problem of spatial separation is further complicated because the skew angle (the angle of the MR head with respect to a track on a disc surface) changes in different zones on the disc surface. Thus, the effective spatial separation in the read and write transducers on the MR head also changes across the disc surface.
Thus, it is desirable to provide a suspension system which can facilitate microactuation control of the slider about the yaw axis to finely position the read and write transducers over the ideal track centers and to compensate for skew angle.

Gimbal suspension for supporting a head in a disc drive assembly


The use in a bituminous composition of an organogelator molecule of the following general formula (I) is disclosed below:

It is known to use bituminous compositions, in particular bitumen/cross-linked polymer compositions, as coatings for various surfaces and, in particular, as road surfacings, provided that these compositions exhibit in combination a certain number of characteristics, in particular mechanical. In order to maintain and/or improve the characteristics and in particular the mechanical properties of a conventional bitumen, bituminous compositions have for a long time been used, in which the bitumen (formed by one or more types of bitumen) is mixed with one or more functional polymers, in particular styrene and butadiene elastomers, these elastomers being optionally chemically cross-linked in situ, optionally using a coupling or cross-linking agent, for example sulphur or at least one of its precursors.
Optimized mechanical characteristics are in particular crucial for road surfacing applications. In addition to the mechanical properties, in the case of bitumens account should be taken of their susceptibility to certain chemical agents. These aggressive chemical agents can be, for example hydrocarbon solvents, in particular petroleum-based solvents such as kerosenes, gas oils and/or gasolines or also products, in particular fluids, used for de-icing and/or defrosting and/or snow removal from aircraft and from taxiing zones. These fluids are for example saline aqueous solutions of potassium, sodium, magnesium and/or calcium, and/or compositions based on ethylene glycol and/or based on propylene glycol. The aggressive effect of such chemical agents builds up with the stresses of intense traffic, in particular of heavy vehicles, and bad weather, which has the detrimental effect of increasing the rapid degradation of carriageways, in particular aircraft runways.
This sensitivity of the bitumens to these aggressive chemical agents, to chemical attack is more particularly problematic for the bitumens constituting for example tarmacs and the surfacings of airport runways, which are made of bituminous mixes (bitumen/aggregates conglomerate). In fact, these airport tarmacs and surfacings are frequently soiled by drips of kerosene during the filling of aircraft tanks, by leaks or other accidental spills of petroleum products. Moreover, they are also exposed to the different fluids used in cold weather to remove ice, frost and/or snow from aircraft and runways.
The surfacings of service stations well as industrial tank farms can also be subject to this same problem of the resistance of the bituminous surfacings to aggressive chemical agents such as hydrocarbon solvents and/or de-icing/defrosting/snow removal fluids. Conventional road carriageways are of course also exposed to this type of chemical attack.
In an attempt to remedy this, it has been proposed to incorporate various additives into bitumens. Thus the patent EP1311619 describes the use of waxes in bitumens in order to increase their resistance to hydrocarbons. The waxes are in particular synthetic waxes resulting from the Fischer Tropsch synthesis process.
In patent application EP1756228 the applicant company proposed incorporating fatty-chain polyamines into the bitumen in order to improve resistance to chemical attack and in particular to hydrocarbons. In patent EP1572807 the applicant company also proposed incorporating into the bitumen, functionalized olefin polymers chosen from the random terpolymers of ethylene, alkyl acrylate or methacrylate and glycidyl acrylate or methacrylate, to improve resistance to petroleum-based solvents. The patent EP0900253 describes the use of ethylene and vinyl acetate copolymers in a bitumen on order to improve resistance to kerosene.

Use of organogelator molecules in bituminous compositions to improve the resistance of same to chemical stress

Abstract: where:                A is a hydrocarbon group which can be straight or branched, saturated or unsaturated, acyclic, cyclic or polycyclic, having 3 to 92 carbon atoms, resulting from the polymerization of lateral chains of at least one unsaturated fatty acid,        X is an NH group or an oxygen atom O,        R1 is a group chosen from: a straight or branched hydrocarbon group with 2 to 40 carbon atoms, optionally including one or more heteroatoms and optionally including one or more unsaturations, or an aromatic group, substituted or otherwise,        R2 is a group selected among: a hydrogen atom, a straight or branched hydrocarbon group with 1 to 40 carbon atoms, including one or more heteroatoms and optionally including one or more unsaturations, or an aromatic group, substituted or otherwise;        m and n are, separately from one another, an integer ranging from 1 to 4,        p is an integer ranging from 0 to 4,        q is an integer ranging from 1 to 4 or a combination of the values,        Y is a group including a hydrogen bond donor such as the NH grouping and a hydrogen bond acceptor such as the C═O grouping, to improve the resistance thereof to aggressive chemical agents, in particular to hydrocarbons such as gasolines, diesels and/or kerosenes.


A container is provided for cell growth by artificial cultivation of selected biological material in a growth liquid for use in an oscillating incubator. The container has a circular bottom with rounded corners joining a sidewall that is inclined at an angle toward a longitudinal axis of the container to define a container volume. The bottom has six equally spaced baffles extending inward from the corners and upward toward a large diameter opening of the container centered on the longitudinal axis. The baffles have a triangular cross-sectional shape with an included angle of about 28–40°, and a height measured parallel to the longitudinal axis of about 15–25% of the usable container volume. The baffles end before the longitudinal axis. The container and baffles are blow molded of a polymer suitable for blow molding. An air permeable filter is placed over the container opening, with the filter having an adhesive on one side to stick to the container. A finger tab on the periphery of the filter helps position and remove the filter.

This invention relates to flasks or containers and systems used for aerobic fermentation used to cultivate the aerobic growth of microorganisms, cell lines or other biological organisms.
For a variety of biotechnology applications there is a need to take a few biological organisms and as quickly as possible, multiply or grow them into significantly larger numbers of organisms. The biological growth usually increases with the oxygen level.
One common method of cultivating biological organisms is to place them in a flask in a liquid medium, and then oscillate the flask at a predetermined rate in an enclosed incubator. This approach can use a flask disclosed in a patent to Tunac, U.S. Pat. No. 4,665,035, which flask uses specific patterns of baffles on the bottom and neck of the flask. But Tunac's use of these baffles, including the internal baffles to inhibit the fluid from splashing out of the flask, has significant disadvantages. The cost of making the Tunac flasks is high enough that they must be reused. Unfortunately, reuse requires cleaning the flasks and filters in an autoclave and despite such cleaning it is not uncommon to have sufficient contaminants remain that reuse of the flask contaminates the samples cultivated in the reused flask. There is thus a need for an efficient flask that overcomes these deficiencies.
Further, the goal of cultivation is to produce as large an increase in the biological organisms as possible in as little time as possible. The use of the prior art containers, such as Tunac, often produce inconsistent growth rates, in part due to residual contamination arising from reuse. There is thus a need for a container that produces an increased growth rate of the biological organisms, consistently, and preferably while reducing the risk of contamination.
The prior art containers allow air to enter the container, and many containers filter the air. For example, Tunac describes a complex ribbed cap and filter to help diffuse oxygen in the flask. But the cap and filter in Tunic's container are expensive to make, and are thus reused, resulting in a risk of contamination and high operating costs. There is thus a need for an improved cap design.
The prior art containers have openings at the top of the containers and laboratory personnel often insert pipettes through these openings to gather samples and add contents from the containers at various stages of cultivating the biological organisms in the containers. As the containers become larger longer pipettes are needed, and laboratory personnel sometimes tilt the containers and spill everything out in using the pipettes. Further, removing and reattaching the caps to access the containers sometimes contaminates the caps. There is thus a need for an improved way to allow sampling of and addition to the contents of the containers while reducing contamination.

Fermentation flask for cultivating microorganisms


Compounds, compositions and methods are contemplated in which senile plaques and/or neurofibrillary tangles are labeled using compounds with improved permeability across the blood brain barrier and improved selective binding to senile plaques and/or neurofibrillary tangles. Contemplated compounds are derivatives of FDDNP or curcumin, which most preferably have improved solubility in aqueous solvents. Labeling is typically performed using a PET detectable label, and especially 11C and 18F.

A definitive diagnosis of the neurodegenerating Alzheimer's disease has been a goal since the disease was first described in 1906. Alzheimer's disease affects 10% of people older than 65 and is characterized by a progressive loss of cognitive function with an abnormal accumulation of β-amyloid senile plaques and neurofibrillary tangles in the brain as its hallmarks. Alzheimer's disease appears to be caused by the misassembly of the β-amyloid peptide, which is a 39-43 amino acid fragment derived from the amyloid precursor protein. This accumulation of these large extracellular aggregates of amyloid β-peptide onto a β-sheet structure forms the senile plaques characteristic of Alzheimer's patients. Histochemical detection of the senile plaques can be carried out using a variety of compounds that can bind to β-sheets. Similarly, neurofibrillary tangles are intracellular structures that are primarily composed of a misfolded protein called tau, which can also be detected by histochemical stains. Unfortunately, these histochemical stains are not suitable for use in living patients since these stains lack significant ability to cross the blood-brain barrier. Moreover, even if such agents could cross the blood-brain barrier, non-radiological detection would be very difficult. Therefore, it is desirable to develop radiotracers to detect the plaque and tangle binding sites, and the most desirable manner of detection is positron emission tomography (PET).
PET is a non-invasive test that helps physicians diagnose abnormalities, determine the extent of disease, prescribe treatment, and/or track progress in therapeutic intervention. Among other advantages, PET allows imaging of biochemical processes of the body well in advance of anatomical changes associated with abnormal physiological states (i.e., cancer, Alzheimer's, etc). In its most common form, PET scans provide images of tissue activity by measuring decay of positrons from a positron-emitting radiopharmaceutical to thereby locates and quantify "hot spots" for tissue activity related to the specific radiotracer.
Imaging agents using PET can therefore greatly enhance chances of early diagnosis of Alzheimer's disease, which then allows patients to obtain the best therapy and most efficient therapeutic drugs early in the disease progression. Development of imaging agents that detect the senile plaques associated with Alzheimer's disease is currently underway. For example, one class of PET imaging agents comprises selected aminonaphthalene backbones, which have been shown to target the polymeric form of the β-amyloid peptide associated with senile plaques and bind to neurofibrillary tangles. One radiofluorinated molecular imaging probe, 2-(1-{6-[(2-[18F]fluoroethyl)(methyl)amino]-2-naphtyl}ethylidene)malonitrile, also known as [18F]FDDNP, became the first diagnostic tool to relatively specifically image plaques and tangles (see e.g., U.S. Pat. Nos. 6,274,119 and 6,660,530). Further related compounds are described in U.S. Pat. App. No. 2007/0053831. However, [18F]FDDNP is highly lipophilic and consequently exhibits some nonspecific binding. Therefore, the results obtained from PET scans using [18F]FDDNP are often relatively poor in image quality and make diagnosis difficult.
Still other known labeling compounds include numerous substituted and radiolabeled benzofuran compounds as described, for example, in U.S. Pat. No. 7,173,061, and numerous substituted quinolinehydrazones as described, for example, in U.S. Pat. No. 6,589,504. Various substituted phenyl imidazo[1,2-b]pyridazine and similar structures are described as imaging agents in WO 2007/033080, and selected substituted benzathiazole compounds are known for labeling and are described in WO 2007/035405. Still further known compounds with more or less specific binding to amyloid are referred to in U.S. Pat. App. No. 2005/0048000. However, and similarly to FDDNP, such known compounds are often problematic with respect to their transport across the blood-brain barrier, stability under physiological conditions, and selectivity towards neurofibrillary tangles and/or senile plaques.
Therefore, while various compositions and methods for imaging senile plaques and/or neurofibrillary tangles are known in the art, all or almost all of them suffer from one or more disadvantages. Thus, there is still a need to provide improved imaging agents for the detection of senile plaques and neurofibrillary tangles.

β-amyloid and neurofibrillary tangle imaging agents

The Regents of the University of California


A densely packed array of vertical semiconductor devices having pillars and methods of making thereof are disclosed. The array has columns of bitlines and rows of wordlines. The gates of the transistors act as the wordlines, while the source or drain regions acts as the bitlines. The array also has vertical pillars, each having a channel formed between source and drain regions. Two transistors are formed per pillar. This is achieved by forming two gates per pillar formed on opposite pillar sidewalls which are along the bitline direction. This forms two wordlines or gates per pillar arranged in the wordline direction. The source regions are self-aligned and located below the pillars. The source regions of adjacent bit lines are isolated from each other without increasing the cell size. Two floating gates per pillar may be used for EEPROM or flash memory application. The isolated sources allow individual cells to be addressed and written via direct tunneling, in both volatile and non-volatile memory cell configurations. For Gbit DRAM applications, stack or trench capacitors may be formed on the pillars, or in trenches surrounding the pillars, respectively. When two capacitors or two floating gates are formed per pillar, the effective memory cell size is 1 bit/2F.sup.2.

1. Field of the Invention
The present invention is directed to densely packed vertical transistors in a 2F-square memory cell, and methods for making thereof, and more particularly, to non-volatile or volatile memory cells having vertical floating-gate transistors, stack capacitors or deep trench capacitors.
2. Discussion of the Prior Art
There is much interest to scale down densely packed semiconductor devices on an integrated circuit (IC) chip to reduce size and power consumption of the chip, and allow faster operation. In order to achieve the high packing density necessary for Gbit memory applications, it is crucial to shrink the size of an individual memory cell as much as possible. FIG. 1 shows a top view of a conventional array 10 of conventional erasable programmable read only memory (EPROM) devices 15, using vertical transistors, such as metal oxide silicon field effect transistors (MOSFETs) with a floating gate layer. The conventional array 10 is described in the following two references. H. Pein and J. D. Plummer, "A 3-D sidewall flash EPROM call and memory array", Electron Device Letters, Vol. 14 (8) 1993 pp.415-417. H. Pein and J. D. Plummer, "Performance of the 3-D Pencil Flash EPROM Cell and Memory Array", IEEE Translations on Election Devices, Vol. 42, No. 11, 1995, pp. 1982-1991.
The conventional array 10 has rows of wordlines 20 and columns of bitlines 25. The size of a cell 27 of the array 10 is 2F by 2F+.DELTA., leading to a cell area of 4F.sup.2 +2F.DELTA.. F is the minimum linewidth of the feature size that can be patterned with lithography. 2F is the cell size along the wordline 20, and 2F+.DELTA. is the cell size along the bitline 25. Typically, .DELTA. is approximately 0.2F, resulting in a cell area of approximately 4F.sup.2 +0.4F area achievable using conventional lithography. The additional length .DELTA. is necessary to separate adjacent wordlines 20.
FIG. 2 shows a partial perspective view of the array 10 of FIG. 1, and FIG. 3 shows a cross sectional view of the vertical MOSFET 15 along a bitline 25.
As shown in FIG. 3, the MOSFET 15 has an n.sup.+ source 30 formed on a P-doped silicon substrate 35. The source 30 is formed after etching the substrate 35 to form a vertical pillar 40, referred to as the body of the MOSFET 15. The pillar 40 acts as the transistor channel and has dimensions of F by F, as shown in FIGS. 1 and 3.
As a result of forming the source 30 after forming the pillars 40, the source 30 is formed around edges of the pillar 40 and is absent from a region 45 located below the pillar 40. Thus, the source 30 does not entirely occupy the footprint of the pillar 40. As shown in FIG. 2, all the MOSFETs 15 of the array 10 have a common source 30, including MOSFETs of different bitlines 25 and different wordlines 20. As shown in FIGS. 2-3, the top of each pillar 40 is doped with N-type material to form n.sup.+ drains 50 of the vertical transistors 15.
A tunnel oxide 60 is formed around the pillar 40 and an oxide spacer 65 is formed on the source 30. Next, a polysilicon floating gate 70, gate oxide 75 and polysilicon control gate 20 are formed around the tunnel oxide 60. Note, control gates 20 of individual transistors along the wordline 20 are inter-connected to form the wordline 20.
Because the polysilicon control gate 20 grows uniformly around each vertical MOSFET 15, the spacing between MOSFETs 15 of adjacent rows is slightly larger than the feature size F, e.g., F+.DELTA., where .DELTA. is approximately 0.2F. This separates adjacent wordlines by amount .DELTA., when polysilicon is grown up to a distance of 0.5F. This 0.5F thick polysilicon layer covers the top and sidewalls of the pillars 40, as well as the oxide spacer 65 located on the substrate 35 at the base of the pillars 40.
The 0.5F thick grown polysilicon regions at pillar sidewalls separated by distance F, along each wordline 20, merge with each other. This forms the wordlines 20 around a row of pillars that are separated by F. However, the 0.5F thick formed polysilicon regions at pillar sidewalls separated by distance F+.DELTA. do not merge. Rather, they remain separated by the distance .DELTA.. At the base of the trenches located between these polysilicon covered pillar sidewalls that are separated by F+.DELTA., the oxide spacer 65 is covered with the 0.5F thick polysilicon.
To separate adjacent wordlines 20, a reactive ion etch (RIE) is performed that removes polysilicon for a thickness of 0.5F. The RIE exposes the top of the pillars 40, as well as the oxide spacer 65 at the base of the pillars that are separated by F+.DELTA.. The exposed distance of the oxide spacer 65 is .DELTA.. Thus, the .DELTA. separation between adjacent wordlines 20 ensures that control gates 20 of adjacent wordlines are not shorted along the direction of the bitlines 25.
As shown in FIGS. 1 and 2, a first level metal forms bitlines 25 which are orthogonal to the wordlines 20. The first level metal connects drains 50 of MOSFETs 15 along a common bitline 25. The area of the cell 27 of FIG. 2, is small because the substrate 35 is used as a common source 30 for all the MOSFETs 15 of the array 10. FIG. 4 shows a three dimensional view of another conventional array 90, which is similar to the conventional array 10 of FIG. 2, except for having round pillars 95 instead of square pillars 40 (FIG. 2). As in the array 10 of FIG. 2, the array 90 of FIG. 4 has a common source 30.
The memory function of each cell 27 is achieved by charging or discharging the floating gate region 70. This causes a measurable shift in the threshold voltage of the vertical MOSFET.
In the conventional EPROM cell 27, the tunnel oxide between the floating gate 70 and the transistor channel or pillar 40 is fairly thick, having a thickness of at least 150.ANG.. Therefore charging of the floating gate 70 must be achieved by flowing a large drain current. This generates hot electrons which can tunnel through the tunnel oxide 60, often referred to as hot-electron injection or channel hot electron tunneling. However, channel hot electron tunneling is not suitable for DRAM or "Flash" memory applications, because channel hot electron tunneling requires high power. This is particularly a problem in the high density arrays necessary for Gbit memories. In addition, tunnel oxide degradation caused by hot electron tunneling is not tolerable for applications that require frequent read/write operations. If the tunnel oxide 60 is made thinner, e.g., .ltoreq.3 nm, direct tunneling between the channel 40 and floating gate 70 is possible. In contrast to hot electron tunneling, direct tunneling is faster resulting in faster write and erase times, requires much lower power, and minimizes tunnel oxide degradation.
However, because the sources 27 of all the MOSFETs are common, setting the bitline and wordline voltages appropriately to write a single cell 27 can still induce hot electron currents in neighboring cells along a wordline 20. This destroys any information in these cells and damages their tunnel oxides 60.
Hence, to make the conventional MOSFETs 15 useful for DRAM/Flash EEPROM applications, the cell must be modified to isolate the source regions 30 between adjacent bitlines 25. This allows use of direct tunneling read/write operations. Furthermore, to achieve the packing density necessary for Gbit memories, the overall cell area must not be increased by these modifications. The cell area must remain approximately 4F-square.
One method for achieving source isolation between bitlines 25 is to pattern isolation lines lithographically between the bitlines 25. Isolation is then be achieved by either a local oxidation of silicon (LOCOS), recessed-LOCOS, or conventional shallow trench techniques.
However, such an isolation method requires lithography. Therefore inter-device 20 lines must be increased from F to at least 2F to avoid shorting adjacent control gates, or wordlines 20 along the bitlines. This increases the inter-device spacing along the bitlines 25 from 1.2F to 2F. Thus, the overall cell size increases from 4F.sup.2 +0.4F to at least 6F.sup.2. Moreover, lithographic misalignments degrades device behavior. Hence, packing density and/or performance is sacrificed in this scheme.
To increase packing density, instead of forming the vertical MOSFET 15 having the pillar 40, an inverted transistor is formed in a trench etched into the substrate. Such transistor structures are shown in U.S. Pat. Nos. 5,386,132; 5,071,782; 5,146,426 and 4,774,556. The transistors formed in such trenches may be combined with additional planar devices, as discussed in U.S. Pat. Nos. 4,964,080; 5,078,498. Other memory cells have transistors with a floating body, as discussed in U.S. Pat. No. 5,382,540. Another conventional memory cell, disclosed in U.S. Pat. No. 5,017,977, does not have separated buried bitlines between transistors. Such conventional cells fail to achieve maximum packing density due to non-self-aligned isolation techniques, or require complex processing methods for fabrication, e.g., selective epitaxial growth, which methods are not suitable for large-scale production. Instead of using the vertical devices of the memory cell 27 as an EPROM, the vertical transistor 15 without a floating gate, in conjunction with a capacitor, can also be used for DRAM applications. FIG. 5 shows a schematic of a typical DRAM cell 100 having a field effect transistor (FET) 105 and a storage capacitor C.sub.s. The gate of the FET 105 acts as the wordline W/L. A bitline B/L is connected to one terminal of the FET 105, which terminal is the source or drain of the DRAM, depending on application. The other DRAM terminal is connected to a storage node 110 of the storage capacitor C.sub.s. The other terminal of the storage capacitor C.sub.s is referred to as a plate 115.
When the FET 105 is turned on by an appropriate signal on the wordline W/L, data is transferred between the bitline B/L and the storage node 110. The standard one transistor, one capacitor cell 100, shown in FIG. 5, has a theoretical minimum area of 8F.sup.2 for a folded bitline, or 4F.sup.2 for an open bitline architecture, shown in FIGS. 6 and 7, respectively.
FIG. 6 shows a top view of a conventional folded bitline DRAM cell 120 having active and passing bitlines B/L, B/L', respectively, and active and passing wordlines W/L, W/L', respectively. The word and bit lines each have a width F. The bit and word lines are separated from adjacent bit and word lines by a width F. Thus the area of the folded bitline DRAM cell 120 is 8F.sup.2.
FIG. 7 shows a top view of a conventional open bitline DRAM cell 150, having a bitline B/L and a wordline W/L, each having a length F and being separated from adjacent lines of adjacent cells (not shown) by a length F. Thus, the area of the open bitline DRAM cell 150 is 4F.sup.2.
Due to the need for contact and isolation spacing, in conventional designs that use planar transistors, it is only possible to obtain these minimum cell sizes by creating sub-lithographic features at some level. In addition, if a minimum cell size is to be obtained, it is necessary to reduce the length of the transistor 105 of FIG. 5 as much as possible (down to F). This reduces the gate length. However, shorter gate lengths result in higher leakage currents which cannot be tolerated. Therefore, the voltage on the bitline must be scaled down accordingly. This reduces the charges stored on the storage capacitor C.sub.s, thus requiring a larger capacitance to ensure that the stored charge is sensed correctly, for example, to indicate logic 1 or 0.
Increasing the capacitance of the storage capacitor C.sub.s is achieved by either increasing the capacitor area, or decreasing the effective dielectric thickness located between the capacitor plates. Increasing the capacitor area is becoming more difficult to do without also increasing the cell size, and hence defeating the purpose of shortening the gate in the first place.
Further reducing the dielectric thickness is also difficult, since the thickness of many conventional dielectrics has already reached a minimum practical thickness. To further reduce the dielectric thickness, alternative dielectrics with higher dielectric constant have been explored. While such alternate dielectrics contribute to solving the problem of low charge storage resulting from the decreased bitline voltage, further bitline voltage reduction is limited by the maximum achievable dielectric constant. Accordingly, to further reduce the bitline voltage, an alternative to reducing the gate length of the transistor 105 is necessary.
In light of the foregoing, there is a need for high density memory cells having isolated sources between adjacent bitlines, yet continuous source regions for each individual bitline, to allow cell programming by direct electron tunneling, instead of programming by channel hot electron tunneling.
There is also a need for a memory cell having a proper gate length and capacitor, without increasing the lateral area of the cell.

2F-square memory cell for gigabit memory applications

International Business Machines Corporation