An axial fan (1) having a motor comprising a stator (2) and a rotor (3), wherein blades (4), which move a gaseous medium in an axially directed main flow direction (S) from an inlet side (E) to an outlet side (A) of the fan, project from the outer periphery (U3) of the rotor (3). For enhanced performance with regard to efficiency in a structurally less costly manner, a rotation-symmetric flow guiding element (5) is mounted on the outlet side (A) directly or indirectly on the stator (2) and concentrically with respect to a stator hub (2a). The flow guiding element to have an outer diameter (D5) that is greater than the outer diameter (D2) of the stator hub (2a) greater than the outer diameter (D3) of the rotor (3), and smaller than the diameter (D4) of a perimeter (U4) around the blades (4).

With fans of the above-referenced type, of which many embodiments are known, one constant development objective is to maximize the attainable efficiency. Efficiency is understood in the narrower sense-only with reference to the fan wheel-to be the ratio of the flow rate of the fan to the power requirement of the fan shaft. For a given shaft power, the efficiency is determined from the conveyed gas volume flow and the total pressure increase produced by the fan. The product of these gives the flow rate, with total pressure being understood according to the so-called Bernoulli equation as the sum of static and dynamic pressure.
This development objective, wherein each percentage point of efficiency increase is important, has gained in relevance in connection with the new formulation of the so-called Ecodesign Directive or ErP Directive (Directive 2009/125/EG of the European Union), which comprises not only energy-using products, but generally energy-related products for the minimization of harmful environmental pollution. This applies both to fans operated as stand-alone devices and to fans that are integrated as components of a device or system. The ErP Directive thereby specifies minimum efficiencies, whereby here efficiency of the entire fan, that is, the unit consisting of the control electronics (if present), motor, and fan wheel is assessed as efficiency in the broader sense.
It is the object of the invention to create an axial fan of the kind described previously, by which improvements of operating performance with regard to efficiency can be attained in a less costly manner. The noise level should not be affected by this, but preferably would be improved.
This object is attained according to the invention by mounting a rotation-symmetric flow guiding element on the outlet side directly or indirectly on the stator and concentrically with respect to a stator hub. Said flow guiding element has an outer diameter that is greater than the outer diameter of the stator hub, greater than the outer diameter of the rotor, and smaller than the diameter of a perimeter around the blades. Such a flow guiding element provided according to the invention, which is mounted in the direction of flow behind the fan, acts advantageously as a blockage or deflector plate for the conveyed gas flow, and prevents a volume flow from being drawn from a region of turbulence behind the motor. Such turbulence zones, which are produced after a stream separates from a body around which it has been flowing, are also called "dead water zones" or "eddy flow regions" in the case where a liquid is the flow medium. There is no laminar flow there.
In addition, the flow guiding element provided according to the invention also ensures that a backflow of flow medium can only begin within a diameter range that is greater than the diameter of the hub, thus restricting backflow. This occurs, in turn, because the backflow must take place against centrifugal force, which increases proportionally with the distance to the fan axis. A backflow zone that arises in particular when using axial fans with high counterpressure can be kept comparatively low according to the invention. Because the flow through the fan separates only when the diameter is greater than the diameter of the hub, up to the time of its separation it can also reach a comparatively higher pressure than when the flow guiding element is not present. The total attainable pressure increase with the fan thereby rises, and the efficiency increases by a few percentage points in comparison with a fan without such a flow guiding element.
The flow guiding element provided according to the invention can be advantageously used together with a protective screen likewise mounted at the outlet side on the stator of the axial fan. At the same time, it can be configured as a separate component or can be integrated into the protective screen, that is to say, mounted in particular thereon or therein. A one-piece configuration with the protective screen is also possible in this regard.
The flow guiding element can be advantageously mounted as a plastic or metal part that may be clipped on, screwed in, riveted, or welded, that is, it can be friction-fitted, form-fitted and/or bonded, in particular in a manner that is less costly from the point of view of production and assembly as a plastic part that can be clipped on or can be configured as a weldable metal part with higher strength in a more robust design.
In a preferred embodiment, the flow guiding element can be configured in a conical shape, in particular with the basic shape of a truncated cone, wherein, when mounted, its jacket surface diverges in a direction facing away from the stator. This has the advantageous effect that the slanted position of the jacket surface causes the flow to be deflected outward and that the flow guiding element thus acquires a better guiding capacity.
Other advantageous embodiments of the invention are contained in the following description.


An EPROM memory cell (32) stores information in a floating gate (44) which overlies a portion of a channel between a program drain (36) and a read drain (34). A control gate (46) has a lower segment (48) which overlies the portion of the channel not covered by the floating gate (44), and has an upper portion (50) overlying the floating gate (44). During a program operation, electrons flow from the read drain (34), acting as a source, to the program drain (36), and hot electrons are stored within the floating gate (44). During a read operation, electrons flow from the programming drain (36) to the read drain (34), and the majority of hot electrons drift to the control gate (46). Since the hot electrons do not enter the floating gate (44) during read operations, a higher driving current can be used, thereby increasing the speed at which the EPROM memory cell (32) is read.

Currently available EPROMs have access times in the 150-200 nanosecond range. As processing circuits have increased in speed, it is desirable that the access rate for EPROMs also be increased.
The access time for EPROMs is particularly important in the field of Electrically Programmable Array Logic, otherwise known as EPAL. In EPAL, the speed at which the logic can function is dependent on how fast the internal EPROM can be read. Thus, the reading speed of the EPROM has a direct correlation to the speed of the EPAL.
Previous solutions to increase the access rate of EPROMs have produced deleterious side effects. The main impediment to increasing EPROM speed is control of "hot electrons," which pass through the oxide above the depletion region into a floating gate. To program the EPROM, hot electrons are purposely forced into the floating gate to create a charge therein. However, during read operations, it is undesirable for hot electrons to penetrate into the oxide region or the floating gate, since the accumulated effect of the passing of hot electrons during read cycles will result in a charge being stored in floating gates which were not programmed, causing "read disturbs."
Although using a high driving current will increase the speed with which an EPROM can be read, the higher driving current produces more hot electrons, resulting in an increased rate of read disturbs. Furthermore, hot electrons can be caught in the oxide between the depletion region and the floating gate, causing breakdown of the oxide region over a period of time.
Previously developed methods of preventing false programming when using higher driving currents have resulted in EPROM cells with increased complexity, and increased size. The increased size of the EPROM results in less space remaining on the semiconductor chip in which to form the array logic. Therefore, currently developed EPALs face a trade-off between logic density and operating speed.
Thus, a need has arisen in the industry for an EPROM structure which allows fast reading access time without substantially increasing the size of the EPROM memory cells.

High speed EPROM with reverse polarity voltages applied to source and drain regions during reading and writing


Service data and service management data traffic in a networked computing environment (e.g., a cloud computing environment) may flow thorough a large number of devices (e.g., storage, network, cache and other devices and appliances) when the data move from one or more source systems to one or more target systems (or end user systems). Embodiments of the present invention provide a data analysis driven approach that detects patterns in data movements, and data traffic can be used to determine placement of certain network service components such as, among others, storage devices and appliances, server devices and appliances, network devices and appliances, etc.

The networked computing environment (e.g., cloud computing environment) is an enhancement to the predecessor grid environment, whereby multiple grids and other computation resources may be further enhanced by one or more additional abstraction layers (e.g., a cloud layer), thus making disparate devices appear to an end-consumer as a single pool of seamless resources. These resources may include such things as physical or logical computing engines, servers and devices, device memory, and storage devices, among others.
Certain complexities may be associated with public and private cloud environments such as: multiple cloud services in a cloud environment, multiple tenants in a cloud environment, multiple data centers, disparate global locations of cloud data centers and end users, sharing of infrastructure elements by multiple cloud services and cloud tenants, etc. Given such potential complexities, challenges may exist in determining optimal network topologies so that network data traffic throughput can be streamlined.

Determining optimal component location in a networked computing environment

International Business Machines Corporation


In an apparatus and method for separate rapid ramming of shells and propellant charges in a heavy artillery gun in which shells and propellant charges, up to the loading operation are separately stored and separately fed to each respective ramming position in the barrel of the gun, the gun includes two magazines disposed one on each side of the barrel of the gun and the loading apparatus for transferring shells and propellant charges to the breech of the barrel. The loading apparatus includes at least one loading cradle with a first track for shells and a second track for propellant charges, each track having a free-flight rammer. The loading cradle is inwardly pivotally mounted between a replenishment position on a side of the gun barrel and in immediate association with a magazine from which the shells and the propellant charges are loaded into the respective tracks and a ramming position in which the first and second tracks are alternately aligned with the main axis of the gun barrel for separately and successively throwing by the free-flight rammer the shells and propellant charges along their respective tracks into their ramming position in the gun barrel. The magazines and the loading cradle are connected with an elevating system of the gun to follow its movements and are therefore be always parallel with the main axis of the gun barrel.

In recent years, the wish to increase the rate of fire also for heavy artillery pieces has grown ever stronger. Consequently, several different designs have been proposed in the art. Many of these are based on the employment of fixed magazines which may be of the revolver type or of other design and from which projectiles and propellant charges, either separately, as a unit, or jointly but without physical connection, are transferred to and rammed home in the gun. With fixed magazines and guns which can be moved both in elevation and in traverse and which thus move in relation to the magazine, at least two angular planes and often also one vertical plane must, as a rule, be overbridged before the shell and its propellant charge can be rammed home. In fully automatic loading, this problem is generally solved with the aid of a plurality of ammunition handling cradles which are each pivotal in their plane. By transferring shells and propellant charges between these cradles, all angular and level differences between the breech of the gun and the angular position of the gun barrel and the magazine can be negotiated. However, such designs are of a highly complex nature and it is doubtful whether their complexity is worth the advantages which are attained in that the relatively heavy magazines can be rendered stationary. In addition, the transfer operations of shell and propellant charge between several raisable and pivotal handling cradles is substantially time consuming so, with the result that it is very difficult, employing these designs, to achieve the extremely short ramming times which are current objectives within the art. One main reason for this is that, in combatting a specific target, the ideal situation is to have several shells launched on their way towards the target already before the first shell strikes home.
Patent specification EP AO 051 119 discloses a loading system for large-caliber artillery pieces in which the shell and propellant charge magazines which are here of revolver type are carriage-fixed but not elevatable with the gun, that is they follow the barrel on its angular alignment but not its elevation. In this design, use is made of separate, moving charge cradles or bridges for transferring shells and propellant charges from each respective revolver magazine to the loading position of the gun immediately outside its breech opening and are there aligned in the main axis of the gun barrel. In turn, the loading cradles are each journalled in its pivotal aim disposed beside the gun barrel, this arm being in turn pivotally journalled about that shaft about which the gun barrel is elevated. Thus, the pivotal arms are each movable in a plane lying parallel with the gun barrel. The axes of rotation of the loading cradle are in their turn disposed in the longitudinal direction of the pivot arms. Thus, in this design a two-step or double-action displacement is required of each respective loading cradle from having received a projectile or propellant charge. First, each respective pivot arm must be swung into a position which corresponds to the breech opening of the gun barrel and each respective shell or propellant charge is rammed home.


The present invention discloses a guide pin, which comprises a base support layer (1) and a protective layer (2). The base support layer (1) is a rod-shaped structure. The protective layer (2) tightly wraps the surface of the base support layer (1). A manufacturing method for the guide pin made of various materials is also disclosed. The guide pin manufactured by the method of the present invention is not prone to bending or deformation and has good corrosion resistance and acid/alkaline resistance properties; it is wear resistant and has of extended service life; it is easy to be processed and is low in cost.

With the increasing capacities of modern communication systems, the demand for multi-core optical fiber connectors is increasing. The existing multi-core connectors mainly use MT-type optical fiber contacts as basic transmission units, and the optical connectors using a single MT-type optical fiber contact mainly include types of MTP, MPO, and MTRJ. The MPO optical fiber connector generally comprises a male head and a female head, the male head of the multi-core optical fiber connector is provided with a guide pin which is fixed to a guide pin base, and the female head has a limiting base at the tail end.
The existing guide pin is generally made of stainless steel and has an annular groove. The groove has a diameter of less than 0.3 mm. Too small a diameter results in a decrease in mechanical strength, so that the tail of the guide pin is easily bent, which affects docking precision. After the male and female heads are installed together, the guide pin can be easily rotated under the action of external force as the groove thereof is annular; as a result, a forced alignment effect between the guide pin and the guide hole is reduced. In addition, the guide pin made from stainless steel has poor corrosion resistance and wear resistance. Moreover, the guide pin made from stainless steel has high toughness, which leads to an increase in processing viscosity and increases processing difficulty.

Guide pin and manufacturing method therefor


Neurite outgrowth and nerve regeneration are promoted by disruption of the steroid receptor complex and stimulation of MAP kinase/kinase activity. This disruption can take the form of disruption of the physical assembly or function of the steroid receptor complex, such as the mature complex or a precursor of the mature complex that is required for assembly of the mature complex. Geldanamycin and its analogs, bastadin and members of the bastadin family, and radicicol and its analogs, as well as FKBP-52 antibody, are shown to disrupt the complex and promote nerve growth. Assays for finding neurotrophic compounds, as well as compounds found by these assays, pharmaceutical compositions into which they are incorporated, and methods of treating subjects having neuronal dysfunction caused by injury or disease are disclosed. Any of these compounds can be used in combination with a therapeutically effective amount of heat, such as heat applied locally to an area where nerve growth is desired, or systemically in an organism in which neurite growth is desired. Alternatively, these compounds can be used in association with a template, such as a tubular member that defines an anatomic pathway along which nerve regeneration is desired (particularly around a transected or partially transected nerve).

This invention concerns neurotrophic compounds and agents useful in the treatment of neurological injury and disease.
Following traumatic or mechanically induced axonal degeneration in the peripheral nervous system, axonal regeneration often ensues, resulting in functional recovery. However, the rate of axonal elongation (3-4 mm/day) is slow, and sometimes does not result in recovery of full neurological function. If neurological function is restored, recovery usually occurs in weeks or months, depending upon the distance between the site of injury and the target tissue. Therapies that speed regeneration over long distances would be highly beneficial to patients and would significantly reduce health care costs.
Other neurological conditions result from dysfunction of neurons in the peripheral or central nervous systems that is caused by chronic disease or injury. Chronic disease processes can permanently and progressively damage the nervous system, and (particularly in the central nervous system) usually results in permanent loss of function. Such loss of neurological function is a major cause of physical incapacitation and death throughout the world.
The immunosuppressant drug FK506 (USAN tacrolimus; Prograf(copyright)) induces immunosuppression by binding the immunophilin FKBP-12. This binding prevents calcineurin from dephosphorylating the transcription factor NF/AT (nuclear factor of activated T-cells), which blocks translocation of calcineurin into the nucleus, and prevents a receptor-mediated increase in the synthesis and secretion of cytokines, such as interleukin-2 (IL-2), which are required for T-cell proliferation. FK506 has also been found to speed functional recovery and axonal regeneration in the rat in a dose-dependent manner following a sciatic nerve crush lesion.
U.S. Pat. No. 5,654,332 (Armistead et al.) discusses immunosuppressive FK506 analogs that bind FKBP-12, and are said to stimulate neurite outgrowth in the presence of NGF. The neurotrophic activity of these FKBP-12 binding compounds was said to be xe2x80x9cdirectly related to their affinity for FKBP-12 and their ability to inhibit FKBP-12 rotamase activityxe2x80x9d (id. at col. 7, lines 47-50). Rotamase activity measures peptidylisomerase cis-trans isomerization, and inhibition of this activity has been accepted as an indication of the immunosuppresant and neurotrophic activity of therapeutic agents. See U.S. Pat. No. 5,614,547 (Hamilton et al.).
Systemic administration of two synthetic FK506 analogs that bind FKBP-12 but that do not inhibit calcineurin activity (and which are not immunosuppressants) have been reported to increase the size of myelinated fibers (Gold et al., Exp. Neurol. 147:269-278, 1997; Steiner et al., Nature Medicine 3:1-8, 1997; Steiner et al., Proc. Natl. Acad. Sci. USA 94:2019-2024, 1997). It has also been reported that androgens and estrogens stimulate facial nerve regeneration in hamsters (e.g. Tanzer and Jones, Exp. Neurol. 146:258-264, 1997).
Many of the compounds previously shown to stimulate nerve regeneration have undesired side-effects, such as immunosuppression (FK506 and analogs that retain immunosuppressant activity) or androgenic or estrogenic stimulation. There is therefore a need to provide a class of nerve growth stimulating compounds that are well tolerated by subjects who take them.
The mechanism by which FK506 and other analogs induces nerve growth stimulation has previously been misunderstood, which has been an obstacle to the development of new drugs for this purpose.
The present invention takes advantage of the surprising discovery that nerve growth stimulation is promoted by disruption of the mature steroid receptor complex, and not by interaction with FKBP-12, as was previously thought. Disruption of the complex can include inhibition of physical assembly, promotion of disassembly, or functional interference with the steroid receptor complex, for example the mature steroid receptor complex, or a less mature form of the complex that is a predecessor to the mature complex. The participation of MAP kinase/kinase (MEK) in stimulating nerve growth, and the role heat plays in increasing neurite outgrowth when combined with nerve growth stimulating compounds, are additional parameters that can be exploited as part of this invention.
In view of the discovery of the biochemical mechanism by which neurite outgrowth is promoted, assays have been developed for selecting new compounds that may have activity in promoting nerve growth. Such assays may include determining if a test compound, other than a steroid ligand such as an androgen or an estrogen, disrupts assembly of the steroid receptor complex, and selecting a compound that disrupts assembly of the steroid receptor complex. Alternatively, the assay may include determining the ability of test compounds to stimulate MEK activity, and selecting compounds on this basis. Examples of specific classes of compounds that can be screened include geldanamycin and its structural analogs, rapamycin and its structural analogs, and FK506 and its structural analogs, radicicol and its analogs and bastadins and their analogs. Compounds selected by this assay for further investigation may be tested in additional assays to measure actual neurite outgrowth induced by the compound. In this way neurotrophic compounds have been identified by the assay for disruption of the steroid receptor complex or stimulation of MEK.
Methods have been designed for stimulating nerve cell growth in a subject by administering to the subject a compound (including a compound discovered by the assay) that disrupts assembly or function of the steroid receptor complex, for example of the mature steroid receptor complex, (for example by inhibiting association or promoting dissociation), or stimulates MEK activity, wherein the compound is other than a ligand for the steroid hormone binding portion of the steroid receptor complex (such as an androgen or an estrogen), and in some specific embodiments does not bind with high affinity to FKBP-12. A therapeutic amount of heat may be administered in combination with nerve growth stimulating compounds. In particular embodiments, the compound is administered to disrupt association of a p23 component of the steroid receptor complex with an hsp-90 component or disrupt association of FKBP-52 with hsp-90. In other embodiments, the compound is administered to competitively bind with ATP at an amino terminal ATP binding site of hsp-90, for example at a geldanamycin binding site of the steroid receptor complex. In yet other embodiments, the compound is administered to stimulate MEK activity. These methods include administration of a benzoquinone ansamycin, such as geldanamycin or a structural analog or mimetic thereof, an anti-FKBP-52 antibody, radicicol or a structural analog or mimetic thereof, or a bastadin or a structural analog or mimetic thereof. The method can also include administering a second neurotrophic factor, other than the compound that disrupts association of the steroid receptor complex.
The method is useful in the treatment of animals (including mammals such as humans) having a neurological condition associated with neuronal dysfunction caused by disease or injury to neurons in either the central or peripheral nervous systems. Compounds or compositions are administered, with or without heat, to the animal in a therapeutically effective neurotrophic amount to bind to the mature steroid receptor complex (for example at a geldanamycin binding site of hsp-90) to disrupt association of the mature steroid receptor complex or stimulate MEK activity, and promote neurite outgrowth from neurons. The method can also be used in association with procedures such as a surgical nerve graft, or other implantation of neurological tissue, to promote healing of the graft or implant, and promote incorporation of the graft or implant into adjacent tissue.
Certain pharmaceutical compounds that are not a ligand for the steroid hormone binding portion of the steroid receptor complex can disrupt assembly of a steroid receptor complex. These compounds can be geldanamycin and its structural analogs, rapamycin and its structural analogs, FK506 and its structural analogs, radicicol or a structural analog or mimetic thereof, or a bastadin or a structural analog or mimetic thereof, but more particular embodiments of the compound may have low rotamase inhibition activity, may be other than an FK506 or rapamycin analog, may not bind with high affinity to FKBP-12, or are not immunosuppressive. In particular embodiments, the compound specifically disrupts formation of the steroid receptor complex (for example the mature steroid receptor complex) either by inhibiting association or promoting dissociation of the steroid receptor complex, for example by disrupting association of a p23 component of the steroid receptor complex with an hsp-90 component, or disrupting association of FKBP-52 with hsp-90, or inhibiting interaction of p23, FKBP-52 or hsp-90 with the complex. Certain embodiments of the compound competitively bind with ATP at an amino terminal ATP binding site of hsp-90, which is also the binding site for geldanamycin binding to the steroid receptor complex. In particular embodiments the compound is radicicol or a radicicol analog that binds to a geldanamycin binding site of hsp-90. In other embodiments, the compound is an anti-FKBP-52 antibody, or another agent that specifically causes FKBP-52 to dissociate from hsp-90 of the steroid receptor complex.
The compound can be incorporated into a pharmaceutical composition, which can also include another neurotrophic factor, such as NGF, IGF-1, xcex1FGF, xcex2FGF, PDGF, BDNF, CNTF, GDNF, NT-3, NT 4/5, and mixtures thereof, or a steroid hormone that is a ligand of the steroid receptor complex (such as an estrogen, an androgen or a corticosteroid such as dexamethasone).
In a more specific aspect, the compound is a nerve growth stimulating amount of an agent that binds to a polypeptide of a steroid receptor complex other than a steroid hormone binding portion of the complex, the agent being selected from the group consisting of an FK506 analog having low binding affinity for FKBP-12 and low rotamase activity, for example a benzoquinone ansamycin and structural analogs thereof, a peptide comprising a sequence of a selected polypeptide component of the complex at a site of interaction between the selected component and another polypeptide component of the complex, an antibody, and combinations thereof, wherein the agent disrupts assembly or interferes with function of the steroid receptor complex by causing p23 or FKBP-52 dissociation from the complex, or inhibiting p23 or FKBP-52 association with the complex, or inhibiting interaction of p23, FkBP-52 or hsp-90 with the complex.
Compounds of the present invention need not have significant calcineurin inhibition or rotamase inhibition. The compounds may have an IC50 for rotamase inhibition of greater than 1 nM, for example greater than 10 nM, 25 nM, or even 50-100 nM.
Nerve cell growth can be stimulated in a subject by administering to the subject a compound that stimulates nerve cell growth, wherein the compound is one or more of radicicol or its analogs; a bastadin or its analogs; or an agent that stimulates MAP kinaseikinase activity. In particular embodiments, the compound is a radicicol analog, or a bastadin such as bastadin 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, particularly bastadin 10, or an analog of a bastadin.
The method also includes administering radicicol or its analogs, or the bastadin or its analogs, in combination with a neurotrophic factor other than the compound that disrupts association of the mature steroid receptor complex or stimulates MAP kinase/kinase activity. The neurotrophic factor may be, for example, NGF, IGF-1, xcex1-FGF, xcex2-FGF, PDGF, BDNF, CNTF, GDNF, NT-3, NT 4/5, and mixtures thereof.
Another aspect is screening for agents that stimulate nerve cell growth, by detecting agents that stimulate MAP kinase/kinase activity, such as radicicol analogs, or platelet derived growth factor BB (PDGFBB) or analogs thereof.
The method also includes applying a sufficient amount of heat to an area where nerve cell growth is desired, for example along a normal anatomic pathway, or in an anatomic region, of a transected, partially transected or otherwise damaged nerve. Alternatively, the body temperature of a subject can be systemically elevated, for example by inducing a fever or placing the body in a heated environment. The invention can also include providing a template in an area where nerve growth is desired, for example a tubular member that defines an anatomical pathway along which nerve growth is desired. If desired, a therapeutically effective amount of the neurotrophic compound may be provided in association with the template to promote nerve growth. The template may be placed between opposing ends of a transected or partially transected nerve. Heat can be applied to the template in a therapeutically sufficient amount, effective to enhance nerve growth. Alternatively, the template along the desired anatomical path can be impregnated with the neurotrophic compound, or the impregnated template can be heated.
In some embodiments, the radicicol compound or its analogs are of the formula:
where X, Y, Z, R1, R2 and R3 are as defined in Example 14, and in particular embodiments is not radicicol.
In some embodiments, the neurotrophic compound is a complete bastadin or bastadin analog, such as,
where each R is independently selected from the group consisting of H, C1-8 alkyl, or sulfato, W is selected from the group consisting of H, OH, or C1-8 alkoxy, X, Y, and Z are independently selected from the group consisting of hydrogen, halogen, hydroxyl, or C1-8 alkoxy, and A and B are carbon atoms that are joined by a single or a double bond. Specific complete bastadin structures (which also show the naturally occurring bastadin macrocylic ring structures) are found in Example 15.
Also included are hemibastadins and their analogs, of the formula
where A, B, R, W, X, and Y are defined as above for the complete bastadins. Specific hemibastadin structures are found in Example 15.
Also included are hemibastadinols and their analogs of the formula
where A, B, R, W, X, and Y are defined as above for the complete bastadins. Specific hemibastadinol structures are found in Example 15.
In other embodiments, the compound is a bastadin subunit such as
where A, B, R, W, and X are defined as above for the complete bastadins. A specific example of a bastadin subunit is shown in Example 15.
The foregoing and various features and advantages of the invention will become more apparent from the following detailed description and accompanying drawings.

Compositions and methods for promoting nerve regeneration


The bead and curtain coating methods for coating photographic compositions on smooth receiving surfaces at speeds about 300 ft/min are improved by the addition of a predictive step for the effect of the receiving surface on coating latitude. This step involves measuring the speed for entraining air for coating aqueous compositions from a nozzle applicator such as a capillary tube on the receiving surface and computing an index value predictive of bead and curtain coating performance.

Coated photographic products normally comprise one or more layers of a hydrophilic colloidal composition. The vehicle for these compositions is usually gelatin and the layers are coated onto substrates including paper and acetate and polyester films. The substrates may possess a thin subbing layer to promote adhesion of the layers. The subbing layer is typically a hydrophilic colloidal composition comprising gelatin and other addenda including a cross-linking agent, other polymers, matte particles, and surfactants.
Sometimes multilayer photographic products are coated in four or more stages that may follow in one continuous manufacturing line. The second and later stages are coated onto product layers that have been coated and dried; only the first stage is coated directly on an original receiving surface of paper or plastic that may be subbed. The product layers are typically dispersions and emulsions in a gelatin vehicle. The compositions typically contain surfactants as dispersing aids. The compositions are chemically complex.
Economical and reliable manufacturing requires high speeds of coating and a robust coating process. Indeed, it is desirable that manufacturing processes be so reliable that the numerous inspection, sorting, disposition, rework steps, and large inventories characteristic of past manufacturing processes be eliminated to reduce cost. At the same time, it is desirable to reduce greatly the time it takes to formulate new products and bring them to market. Reduced cycle time, as it is called, can make the difference between success and failure in the highly competitive global marketplace. As coating speeds have increased for economic reasons, significant differences in coating latitude among receiving surfaces have become apparent. Manufacturing photographic products may involve several coating operations with as many different receiving surfaces, any one of which may limit productivity. So, it is important that all receiving surfaces be conducive to coating.
The importance of the surface properties of the receiving surface to coating performance has been largely unrecognized in public technical literature; for example, Buonopane R A, Gutoff E B, & Rinmore MMTR, 1986, AIChE J., 32, p. 682, and Burley, R., 1992, JOCCA., 5, p. 192. However, in formulating and coating photographic products, large differences among receiving surfaces are observed. For example, the limit of coating speed, usually marked by the entrainment of air between the coating compositions and the receiving surface, can vary by an order of magnitude. A receiving surface with poor properties can severely restrict manufacturing performance. Thus, the ability to predict coating performance on various receiving surfaces quickly and inexpensively can be useful and valuable.
Although coating performance cannot be left to chance, methods to predict performance quickly and inexpensively are virtually nonexistent. Past experience with compositions can be helpful, but it is difficult to recognize when a significant change has been made given the chemical complexity of photographic compositions. Predictions based on scientific and engineering models and principles are not possible because much of coating mechanics, and particularly the high speed wetting of a receiving surface that is the heart of coating, remains an enigma (for example, Shikhmurzaev, Y. D., J Fluid Mech., 334, 1997). As a result, in the prior art coating performance is evaluated empirically on pilot coating machines. These coating machines are called pilot machines because they are much narrower than production coating machines, but they must otherwise duplicate manufacturing conditions such as speed. Such pilot machines are therefore expensive to build, operate, and maintain. Thus, the predictive step of pilot coating practiced in prior art is costly and time consuming and at odds with the modern manufacturing objectives already recited. What may be an even worse drawback is that materials being evaluated for new product formulations may not be readily available in the quantities required for high speed pilot coating. So, costly delays in product programs or compromised formulations can result.
One useful method for characterizing the coating latitude of receiving surfaces and maximizing coating speeds based on the results has been disclosed in European Patent Application EP 0 769 717 A1. The method involves measuring the free energy components of receiving surfaces and ensuring through materials selection that these components lie within specified ranges. Specifically, static advancing contact angles of suitably chosen test liquids (water, 1-bromonaphthalene, and 2,2'-thiodiethanol) on the receiving surface are measured, and the method of Fowkes (1962, J. Phys. Chem., 66, p. 382) is employed to determine the free energy components of the receiving surface.
This method for evaluating receiving surfaces for coating speed is useful but has some drawbacks and limitations. The method has proven most reliable for predominantly gelatin/surfactant receiving surfaces, as subbed film is likely to be. Suitable test liquids cannot be found in all cases. The reliable measurement of static advancing contact angles requires considerable skill and experience. Phenomena that occur over the relatively long time of a contact angle measurement but do not occur to a meaningful extent in a coating process can invalidate a measurement. For instance, the test liquid may be adsorbed by the receiving surface, or components of the receiving surface may dissolve or leech into the test liquid, thereby rendering the data questionable. In addition, the time it takes for the test liquid to equilibrate severely limits the capability of the test. So, for some receiving surfaces the method cannot be carried out or the prediction is uncertain.
It would be advantageous to devise a method for evaluating the coatability of substrates for various coating and the appropriate coating temperatures for coating operations for photographic film and paper without having to use a pilot plant operation to determine each situation individually and to avoid the time-consuming process described in European Patent Application 0 769 717 A1.


The present invention provides oligonucleotide primers, compositions, and kits containing the same for rapid identification of viruses that cause viral hemorrhagic fevers by amplification of a segment of viral nucleic acid followed by molecular mass analysis.

A. Viral Hemorrhagic Fever
Viral hemorrhagic fevers (VHFs) are a group of febrile illnesses caused by RNA viruses from several viral families. These highly infectious viruses lead to a potentially lethal disease syndrome characterized by fever, malaise, vomiting, mucosal and gastrointestinal (GI) bleeding, edema and hypotension. The four viral families known to cause VHF disease in humans include Arenaviridae, Bunyaviridae, Filoviridae and Flaviviridae.
In acute VHF, patients are extremely viremic, and mRNA evidence of multiple events cytokine activation exists. In vitro studies reveal these cytokines lead to shock and increased vascular permeability, the basic pathophysiologic processes most often seen with VHF. Multi-system organ failure affecting the hematopoietic, neurologic and pulmonary systems often accompanies the vascular involvement. Another prominent pathologic feature is pronounced macrophage involvement. Inadequate or delayed immune response to these novel viral antigens may lead to rapid development of overwhelming viremia. Extensive infection and necrosis of affected organs also are described. Hemorrhagic complications are multifactorial and are related to hepatic damage, consumptive coagulopathy and primary marrow injury to megakaryocytes. Aerosol transmission of some VHF viruses is reported among nonhuman primates and likely is a mode of transmission in patients with severe infection. Specific symptoms of VHF and modes of transmission vary depending on the particular viral pathogen.
B. Filoviruses
Filoviruses are enveloped viruses with a genome consisting of one linear single-stranded RNA segment of negative polarity. The viral genome encodes 7 proteins. Nucleoprotein (NP), virion protein 35 kDa (VP35) and virion protein 30 kDa (VP30) are associated with the viral ribonucleoprotein complex. VP35 is known to be required for virus replication and is thought to function as a polymerase cofactor. The viral RNA-dependent RNA polymerase is termed L (for large protein). The matrix protein (VP40) is the major protein of the viral capsid. The remaining proteins include virion glycoprotein (GP) and membrane-associated protein (VP24), which is thought to form ion channels. The Ebola viruses have one additional protein, small secreted glycoprotein (SGP).
Members of the filovirus genus include Zaire Ebola virus, Sudan Ebola virus, Reston Ebola virus, Cote d'Ivoire Ebola virus and Marburg virus. Ebola and Marburg viruses can cause severe hemorrhagic fever and have a high mortality rate. Ebola virus (Zaire and Sudan species) was first described in 1976 after outbreaks of a febrile, rapidly fatal hemorrhagic illness were reported along the Ebola River in Zaire (now the Democratic Republic of the Congo) and Sudan. Sporadic outbreaks have continued since that time, usually in isolated areas of central Africa. In 1995, eighteen years after the first outbreak was reported, Zaire Ebola reemerged in Kikwit, Zaire with 317 confirmed cases and an 81% mortality rate. The natural host for Ebola viruses is still unknown. Marburg virus, named after the German town where it was first reported in 1967, is primarily found in equatorial Africa. The host range of Marburg virus includes non-human and human primates. Marburg made its first appearance in Zimbabwe in 1975 and was later identified in other African countries, including Kenya (1980 & 1987) and Democratic Republic of the Congo (1999). Marburg hemorrhagic fever is characterized by fever, abdominal pain, hemorrhage, shock and a mortality rate of 25% or greater ("The Springer Index of Viruses," pgs. 296-303, Tidona and Darai eds., 2001, Springer, N.Y.).
C. Flaviviruses
Flaviviridae is a family of viruses that includes the genera flavivirus, hepacivirus and pestivirus. Viruses in the genus flavivirus are known to cause VHFs. Flaviviruses are enveloped viruses with a genome consisting of one linear single-stranded RNA segment of positive polarity. The RNA genome has a single open reading frame and is translated as a polyprotein. The polyprotein is co- and post-transcriptionally cleaved by cell signal peptidase and the viral protease to generate individual viral proteins. Viral structural proteins include capsid (C), precursor to M (prM), minor envelope (M) and major envelope (E). Flavivirus non-structural proteins include NS1, NS2A, NS2B, NS3, NS4A, NS4B and NS5. NS1, NS2A, NS3 and NS4A are found in the viral replicase complex. In addition, NS3 is known to function as the viral protease, helicase and NTPase. NS2B is a co-factor for the protease function of NS3. NS5 is the viral RNA-dependent RNA polymerase and also has methyltransferase activity.
Members of the flavivirus genus include yellow fever virus, Apoi virus, Aroa virus, Bagaza virus, Banzi virus, Bouboui virus, Bukalasa bat virus, Cacipacore virus, Carey Island virus, Cowbone Ridge virus, Dakar bat virus, dengue virus, Edge Hill virus, Entebbe bat virus, Gadgets Gully virus, Ilheus virus, Israel turkey meningoencephalomyelitis virus, Japanese encephalitis virus, Jugra virus, Jutiapa virus, Kadam virus, Kedougou virus, Kokobera virus, Koutango virus, Kyasanur Forest disease virus, Langat virus, Louping ill virus, Meaban virus, Modoc virus, Montana myotis leukoencephalitis virus, Murray Valley encephalitis virus, Ntaya virus, Omsk hemorrhagic fever virus, Phnom Phenh bat virus, Powassan virus, Rio Bravo virus, Royal Farm virus, Saboya virus, Sal Vieja virus, San Perlita virus, Saumarez Reef virus, Sepik virus, St. Louis encephalitis virus, Tembusu virus, tick-borne encephalitis virus, Tyuleniy virus, Uganda S virus, Usutu virus, Wesselsbron virus, West Nile virus, Yaounde virus, Yokose virus, Zika virus, cell fusing agent virus and Tamana bat virus.
A number of flaviviruses cause human disease, particularly hemorrhagic fevers and encephalitis. Each species of flavivirus has a unique geographic distribution; however, taken together, flaviviruses, and flavivirus-induced disease, can be found world-wide. One of the more commonly known diseases is dengue fever, or dengue hemorrhagic fever/shock, which was first described as a virus-induced illness in 1960. Dengue fever occurs in tropical and temperate climates-and is spread by Aedes mosquitoes. The mortality rate is 1-10% and symptoms include febrile headache, joint pain, rash, capillary leakage, hemorrhage and shock. Another common flavivirus-induced disease is yellow fever. Yellow fever is found in tropical Africa and America and is transmitted by mosquitoes. The mortality rate is approximately 30% and symptoms include febrile headache, myalgia (muscle pain), vomiting and jaundice. Examples of some of the other diseases caused by flavivirus species include Japanese encephalitis, Kyasanur Forest disease, Murray Valley encephalitis, Omsk hemorrhagic fever, St. Louis encephalitis and West Nile fever. The mortality rate of these diseases ranges from 0-20%. These diseases share many of the same symptoms, which may include headache, myalgia, fever, hemorrhage, encephalitis, paralysis and rash ("The Springer Index of Viruses," pgs. 306-319, Tidona and Darai eds., 2001, Springer, N.Y).
D. Bunyaviridae
Bunyaviridae is a family of viruses that includes the genera bunyavirus, phlebovirus, nairovirus, hantavirus and tospovirus. Viruses in three of these genera, hantavirus, phlebovirus and nairovirus, are known to cause VHFs. Members of the Bunyaviridae family are enveloped viruses with a genome that consists of 3 single-stranded RNA segments of negative polarity. The genome segments are designated S (small), M (medium) and L (large). The S segment encodes the nucleocapsid protein (N). The two viral glycoproteins (G1 and G2) are encoded by the M segment and the L segment encodes the viral RNA-dependent RNA polymerase (L). For some Bunyaviridae species, additional viral non-structural proteins are encoded by the S and/or M segment ("The Springer Index of Viruses," pgs. 141-174, Tidona and Darai eds., 2001, Springer, N.Y.).
Members of the hantavirus genus include, Hantaan virus, Seoul virus, Dobrava-Belgrade virus, Thailand virus, Puumala virus, Prospect Hill virus, Tula virus, Khabarovsk virus, Topografov virus, Isla Vista virus, Sin Nombre virus, New York virus, Black Creek virus, Bayou virus, Caño Delgadito virus, Rio Mamore virus, Laguna Negra virus, Muleshoe virus, El Moro Canyon virus, Rio Segundo virus, Andes virus and Thottapalayam virus. Hantaviruses have a wide geographic distribution and typically cause either hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS). Symptoms of HFRS include fever, hemorrhage and renal damage, with a mortality rate up to 15%, depending on the hantavirus species. The first documented case of HFRS occurred in 1934 with a notable epidemic among United Nations soldiers during the Korean War (1951). However, the causative agent of HFRS, Hantaan virus, was not isolated until 1978 (Lee et al. J. Inf. Dis., 1978, 137, 298-308). Symptoms of HPS include fever, pulmonary edema, shock and interstitial pneumonitis (a type of pneumonia involving connective tissue). Sin Nombre virus and Andes virus are two of the hantaviruses that cause a severe form HPS, with an approximately 40% mortality rate. A significant outbreak of pulmonary syndrome occurred in the Southwestern United States in 1993. The etiologic agent of the outbreak was later identified as a hantavirus (Sin Nombre) (Nichol et al. Science, 1993, 262,914-917). The typical route of transmission for hantaviruses is through rodent excreta aerosols, however, Andes virus has been associated with person-to-person transmission ("The Springer Index of Viruses," pgs. 141-174, Tidona and Darai eds., 2001, Springer, N.Y.; Wells et al. Emerg. Infect. Dis., 1997, 3, 171-174).
Members of the phlebovirus genus include Bujaru virus, Chandiru virus, Chilibre virus, Frijoles virus, Punta Toro virus, Rift Valley Fever virus, Salehebad virus, Sandfly fever Naples virus, Uukuniemi virus, Aguacate virus, Anhanga virus, Arboledas virus, Arumowot virus, Caimito virus, Chagres virus, Corfou virus, Gabek Forest virus, Gordil virus, Itaporanga virus, Odrenisrou virus, Pacui virus, Rio Grande virus, Sandfly fever Sicilian virus, Saint-Floris virus and Urucuri virus. Several phleboviruses (e.g., Sandfly fever Naples virus, Sandfly fever Sicilian virus, Chandiru virus and Chagres virus) cause phlebotomus fever, which is typically found in America and the Mediterranean region. Phlebotomus fever, a non-fatal disease, is transmitted by phlebotomines (sand flies) and induces fever, myalgia (muscle pain) and other flu-like symptoms. Rift Valley fever virus, transmitted by mosquitoes, causes a disease of the same name in Africa. Rift Valley fever is characterized by hemorrhagic fever, hepatitis and encephalitis.
Members of the nairovirus genus include Crimean-Congo hemorrhagic fever virus, Dera Ghazi Khan virus, Dugbe virus, Hughes virus, Nairobi sheep disease virus, Qalyub virus, Sakhalin virus and Thiafora virus. Nairoviruses are primarily found in Africa, Asia, Europe and the Middle East. In humans, nairoviruses can cause hemorrhagic fever (Crimean-Congo hemorrhagic fever), Nairobi sheep disease and Dugbe disease. Nairoviruses are typically transmitted to humans by ticks. The first recognized description of Crimean-Congo hemorrhagic fever dates back to the year 1110. This disease is characterized by sudden onset of fever, nausea, severe headache, myalgia and hemorrhage. The mortality rate is approximately 30%. Nairobi sheep disease symptoms include fever, joint pains and general malaise, while Dugbe disease results in fever and prolonged thrombocytopenia (abnormal reduction in platelets) ("The Springer Index of Viruses," pgs. 141-174, Tidona and Darai eds., 2001, Springer, N.Y.).
E. Arenaviruses
Arenavirus is the sole genus of the family Arenaviridae. Arenaviruses are enveloped viruses with a genome that consists of 2 single-stranded RNA segments of negative polarity. The negative-sense RNA of the arenavirus genome serves as both a template for transcription of complementary RNA as well as a template for protein synthesis (ambisense RNA). The genome segments are designated S, which encodes the nucleocapsid protein (NP) and the precursor glycoprotein (GPC), and L, which encodes the zinc-binding protein (Z) and the RNA-dependent RNA polymerase (L).
Members of the arenavirus genus include lymphocytic choriomeningitis virus (LCMV), Lassa virus, Ippy virus, Mobala virus, Mopeia virus, Amapari virus, Flexal virus, Guanarito virus, Junin virus, Latino virus, Machupo virus, Parana virus, Pichinde virus, Pirital virus, Oliveros virus, Sabia virus, Tacaribe virus, Tamiami virus, Whitewater Arroyo virus and Pampa virus. A number of arenaviruses are known to cause disease in humans, including LCMV, Lassa virus, Junin virus, Machupo virus, Guanarito virus and Sabia virus. LCMV has a world-wide geographic distribution and infection with LCMV leads to fever, malaise, weakness, myalgia and severe headache. The remaining disease-causing arenaviruses are more limited in their distribution. Lassa fever is found in West Africa and is characterized by fever, headache, dry cough, exudative pharyngitis and hemorrhage. Sabia fever is found is Brazil with symptoms including fever, headache, myalgia (muscle pain), nausea, vomiting and hemorrhage. Junin virus, Machupo virus and Guanarito virus are the causative agents of Argentinean hemorrhagic fever, Bolivian hemorrhagic fever and Venezuelan hemorrhagic fever, respectively, and as their names suggest, are found only in Argentina, Bolivia and Venezuela. Symptoms of these hemorrhagic fevers include malaise, fever, headache, arthralgia (joint pain), nausea, vomiting, hemorrhage and CNS involvement ("The Springer Index of Viruses," pgs. 36-42, Tidona and Darai eds., 2001, Springer, N.Y).
F. Bioagent Detection
A problem in determining the cause of a natural infectious outbreak or a bioterrorist attack is the sheer variety of organisms that can cause human disease. There are over 1400 organisms infectious to humans; many of these have the potential to emerge suddenly in a natural epidemic or to be used in a malicious attack by bioterrorists (Taylor et al., Philos. Trans. R. Soc. London B. Biol. Sci., 2001, 356, 983-989). This number does not include numerous strain variants, bioengineered versions, or pathogens that infect plants or animals.
Much of the new technology being developed for detection of biological weapons incorporates a polymerase chain reaction (PCR) step based upon the use of highly specific primers and probes designed to selectively detect individual pathogenic organisms. Although this approach is appropriate for the most obvious bioterrorist organisms, like smallpox and anthrax, experience has shown that it is very difficult to predict which of hundreds of possible pathogenic organisms might be employed in a terrorist attack. Likewise, naturally emerging human disease that has caused devastating consequence in public health has come from unexpected families of bacteria, viruses, fungi, or protozoa. Plants and animals also have their natural burden of infectious disease agents and there are equally important biosafety and security concerns for agriculture.
An alternative to single-agent tests is to do broad-range consensus priming of a gene target conserved across groups of bioagents. Broad-range priming has the potential to generate amplification products across entire genera, families, or, as with bacteria, an entire domain of life. This strategy has been successfully employed using consensus 16S ribosomal RNA primers for determining bacterial diversity, both in environmental samples (Schmidt et al., J. Bact., 1991, 173, 4371-4378) and in natural human flora (Kroes et al., Proc Nat Acad Sci (USA), 1999, 96, 14547-14552). The drawback of this approach for unknown bioagent detection and epidemiology is that analysis of the PCR products requires the cloning and sequencing of hundreds to thousands of colonies per sample, which is impractical to perform rapidly or on a large number of samples.
Conservation of sequence is not as universal for viruses, however, large groups of viral species share conserved protein-coding regions, such as regions encoding viral polymerases or helicases. Like bacteria, consensus priming has also been described for detection of several viral families, including coronaviruses (Stephensen et al., Vir. Res., 1999, 60, 181-189), enteroviruses (Oberste et al., J. Virol., 2002, 76, 1244-51); Oberste et al., J. Clin. Virol., 2003, 26, 375-7); Oberste et al., Virus Res., 2003, 91, 241-8), retroid viruses (Mack et al., Proc. Natl. Acad. Sci. U.S.A., 1988, 85, 6977-81); Seifarth et al., AIDS Res. Hum. Retroviruses, 2000, 16, 721-729); Donehower et al., J. Vir. Methods, 1990, 28, 33-46), and adenoviruses (Echavarria et al., J. Clin. Micro., 1998, 36, 3323-3326). However, as with bacteria, there is no adequate analytical method other than sequencing to identify the viral bioagent present.
In contrast to PCR-based methods, mass spectrometry provides detailed information about the molecules being analyzed, including high mass accuracy. It is also a process that can be easily automated. DNA chips with specific probes can only determine the presence or absence of specifically anticipated organisms. Because there are hundreds of thousands of species of benign pathogens, some very similar in sequence to threat organisms, even arrays with 10,000 probes lack the breadth needed to identify a particular organism.
There is a need for a method for identification of bioagents which is both specific and rapid, and in which no culture or nucleic acid sequencing is required. Disclosed in U.S. Patent Application Publication Nos. 2003-0027135, 2003-0082539, 2003-0228571, 2004-0209260, 2004-0219517 and 2004-0180328, and in U.S. application Ser. Nos. 10/660,997, 10/728,486, 10/754,415 and 10/829,826, all of which are commonly owned and incorporated herein by reference in their entirety, are methods for identification of bioagents (any organism, cell, or virus, living or dead, or a nucleic acid derived from such an organism, cell or virus) in an unbiased manner by molecular mass and base composition analysis of "bioagent identifying amplicons" which are obtained by amplification of segments of essential and conserved genes which are involved in, for example, translation, replication, recombination and repair, transcription, nucleotide metabolism, amino acid metabolism, lipid metabolism, energy generation, uptake, secretion and the like. Examples of these proteins include, but are not limited to, ribosomal RNAs, ribosomal proteins, DNA and RNA polymerases, RNA-dependent RNA polymerases, RNA capping and methylation enzymes, elongation factors, tRNA synthetases, protein chain initiation factors, heat shock protein groEL, phosphoglycerate kinase, NADH dehydrogenase, DNA ligases, DNA gyrases and DNA topoisomerases, helicases, metabolic enzymes, and the like.
To obtain bioagent identifying amplicons, primers are selected to hybridize to conserved sequence regions which bracket variable sequence regions to yield a segment of nucleic acid which can be amplified and which is amenable to methods of molecular mass analysis. The variable sequence regions provide the variability of molecular mass which is used for bioagent identification. Upon amplification by PCR or other amplification methods with the specifically chosen primers, an amplification product that represents a bioagent identifying amplicon is obtained. The molecular mass of the amplification product, obtained by mass spectrometry for example, provides the means to uniquely identify the bioagent without a requirement for prior knowledge of the possible identity of the bioagent. The molecular mass of the amplification product or the corresponding base composition (which can be calculated from the molecular mass of the amplification product) is compared with a database of molecular masses or base compositions and a match indicates the identity of the bioagent. Furthermore, the method can be applied to rapid parallel analyses (for example, in a multi-well plate format) the results of which can be employed in a triangulation identification strategy which is amenable to rapid throughput and does not require nucleic acid sequencing of the amplified target sequence for bioagent identification.
The result of determination of a previously unknown base composition of a previously unknown bioagent (for example, a newly evolved and heretofore unobserved virus) has downstream utility by providing new bioagent indexing information with which to populate base composition databases. The process of subsequent bioagent identification analyses is thus greatly improved as more base composition data for bioagent identifying amplicons becomes available.
The present invention provides, inter alia, methods of identifying unknown viruses, including viruses of the Filoviridae, Flaviviridae, Bunyaviridae and Arenaviridae families. Also provided are oligonucleotide primers, compositions and kits containing the oligonucleotide primers, which define viral bioagent identifying amplicons and, upon amplification, produce corresponding amplification products whose molecular masses provide the means to identify viruses of the Filoviridae, Flaviviridae, Bunyaviridae and Arenaviridae families at the sub-species level.

Compositions for use in identification of viral hemorrhagic fever viruses


In some examples, a circuit is configured to receive an input signal and deliver, based on the input signal, a charging current to a capacitor. The circuit may be further configured to receive an output voltage that indicates a charge on the capacitor. The circuit may be further configured to determine that the output voltage is shorted to a reference ground. The circuit may be further configured to reduce, based on determining that the output voltage is shorted to the reference ground, the charging current.

A power supply unit may convert one form of electrical energy to another form of electrical energy. An energy source, such as a battery or an electrical grid, may input electrical energy to the power supply unit. In the example of the electrical grid, the power supply unit may receive alternating current ("AC") at 120 volts with a frequency of 60 Hertz.
Electronic devices, such as laptops, mobile devices, tablets, and others, may require electrical energy in the form of direct current ("DC"). Therefore, a power supply unit may convert an AC signal to DC current or DC voltage for an electronic device.

Protection and management of a power supply output shorted to ground


There is provided a grease composition useful for bearings of cars and aircraft which is stable in a wide range of temperature of 40 to 180xc2x0 C. and exhibits low torque properties under high loading at low temperatures. A low torque grease composition having dynamic viscosity (40xc2x0 C.) of 40 to 150 mm2/sec which comprises a base oil consisting of (a) straight-chain perfluoropolyether oil having dynamic viscosity (40xc2x0 C.) of 25 mm2/sec or less and represented by the following general formula: RfO(CF2O)p(C2F4O)q(C3F6O)rRf, wherein Rf is a perfluoro lower alkyl group and all of p, q and r is an integer and a sum thereof is an integer of 25 to 45 and (b) straight-chain perfluoropolyether oil having dynamic viscosity (40xc2x0 C.) of 250 mm2/sec or more and represented by the following general formula: RfO(CF2O)p(C2F4O)q(C3F6O)rRf, wherein Rf is a perfluoro lower alkyl group and p, q and r are an integer of 10 to 20; and (c) polytetrafluoroethylene as a thickener.

This application claims all rights of priority to Japanese Patent Application No. 2002-006792 filed on Jan. 15, 2002, (pending).
1. Field of the Invention
This invention relates to a low torque grease composition, and more particularly relates to a low torque grease composition comprising perfluoropolyether oil as a base oil and polytetrafluoroethylene as a thickener, and a motor bearing for cars or aircraft to which such a composition is applied. Further, this invention relates to a bearing grease composition for electric controlling throttle motors, and more particularly relates to a fluorine grease composition of improved properties exhibiting low torque at low temperatures, long durability and effective applicability at low and high temperatures when the present grease is filled in a bearing.
2. Prior Art
Grease to be injected in a motor bearing for cars and aircraft is required to have constant properties in a wide range of temperatures postulated in the severely cold polar regions and the broiling deserts ranging from xe2x88x9240 to 180xc2x0 C.
Although a variety of investigations have been done to satisfy such properties, in fact, there is yet room for further improvement thereof.
Requirements for a bearing grease composition used to cars and, in particular, electric controlling throttle motors include low torque, i.e., low rotational torque at room temperature and low temperatures, high acoustical properties, less leakage or volatility, long durability, and effective applicability in a wide range of low to high temperatures ranging from xe2x88x9240 to 180xc2x0 C. Especially for bearings of severe requirements, there is used fluorine grease of high properties such as improved high-temperature durability, oxidative stability and chemical resistance or outstanding low-temperature performance.
Conventional fluorine grease comprises perfluoropolyether as a base oil, tetrafluoroethylene copolymer as a thickener and a small amount of other components such as a rust preventing agent or corrosion inhibitor. When further low-temperature performance is required, a straight-chain perfluoropolyether oil having low-temperature performance is used.
Because of recent strong requirements, it is impossible for such fluorine grease to satisfy a required level of resistance to low-temperature torque under load and durability. In order to meet such severer requirements, there is proposed a grease composition by Japanese Patent No. 7-102,274, which comprises a liquid fluorinated polymer and a hexagonal boron nitride powder of double-humped particle size distribution. The proposed grease composition has excellent heat resistance and bearing durability, while there is no disclosure with regard to low-temperature torque properties.
The inventors have eagerly investigated to develop a grease composition useful for bearings of cars and aircraft which is stable in a wide range of temperature of 40 to 180xc2x0 C. and exhibits low torque properties under high loading at low temperatures. As a result, there are provided a grease composition of markedly lower torque compared with those conventional grease compositions comprising perfluoropolyether oil as a base oil and a low torque grease composition useful for motor bearings of cars and, in particular, of electric controlling throttle motor, or for those bearings of aircraft.
Further, the inventors have investigated to develop a fluorine grease composition of low torque and long durability under a condition of high load and low temperatures useful for rolling bearings, which meets requirements of bearings for electric controlling throttle motor.
It has been found that objects of the invention can be achieved by using a perfluoropolyether oil as a base oil limited only to a straight-chain polymer excluding branched one as a polymer compound of both high and low molecular weight, and a polytetrafluoroethylene fine powder as a thickener. This invention has been developed on the basis the above mentioned fact.
More concretely, a low torque grease composition having dynamic viscosity (40xc2x0 C.) of 40 to 150 mm2/sec and stability in a wide range of temperature ranging from xe2x88x9240 to 180xc2x0 C. can be obtained by using a base oil consisting of (a) straight-chain perfluoropolyether oil having dynamic viscosity (40xc2x0 C.) of 25 mm2/sec or less and represented by the following general formula:
RfO(CF2O)p(C2F4O)q(C3F6O)rRf
wherein Rf is a perfluoro lower alkyl group and p, q and r are 0 or an integer less than 10, and (b) straight-chain perfluoropolyether oil having dynamic viscosity (40xc2x0 C.) of 250 mm2/sec or more and represented by the following general formula:
RfO(CF2O)p(C2F4O)q(C3F6O)rRf
wherein Rf is a perfluoro lower alkyl group and p, q and r are 0 or an integer of 10 to 200; and (c) polytetrafluoroethylene as a thickener.
A straight-chain perfluoropolyether oil used in the invention is represented by the following general formula:
RfO(CF2O)p(C2F4O)q(C3F6O)rRf
wherein Rf is a perfluoro lower alkyl group and p, q and r are an integer of 200 or less; and preferably a straight-chain perfluoropolyether oil of the above mentioned molecular structure wherein r=0.
The reason why a straight-chain perfluoropolyether oil comprising a group of chemical formula (C3F6O)r causes to increase the viscosity and thus the torque at low temperatures is because of lower viscosity index thereof compared with that of a straight-chain perfluoropolyether oil without the group (C3F6O)r. Accordingly, the torque at lower temperatures can be further decreased by using the above mentioned straight-chain perflouoropolyether of the molecular formula wherein r=0. More concretely, the following compound is used:
RfO(CF2CF2O)m(CF2O)nRf
wherein m+n=3 to 200 and m/n=10/90 to 90/10. This compound is obtained by photo-oxidative polymerization of tetrafluoroethylene followed by complete fluorination of thus polymerized precursor.
A straight-chain perfluoropolyether oil as a component (a) used herein has lower molecular weight and dynamic viscosity (40xc2x0 C.) of 25 mm2/sec or less, and preferably 5 to 25 mm2/sec (according to JIS K-2283; xe2x88x9240xc2x0 C.). When the dynamic viscosity (40xc2x0 C.) is lower than the above mentioned level, it is impossible to use such a component (a) to heat resistant grease because of an increase in evaporation loss.
A straight-chain perfluoropolyether oil as a component (b) to be mixed with the component (a) has higher molecular weight and dynamic viscosity (40xc2x0 C.) of 250 mm2/sec or more, and preferably 250 to 500 mm2/sec (according to JIS K-2283; xe2x88x9240xc2x0 C.). The component (b) having dynamic viscosity (40xc2x0 C.) higher than the above mentioned level causes an increase in torque at low temperatures if the grease is used in a general manner because of higher pour point thereof (JIS K-2283).
These perfluoropolyether oils of different viscosity have different properties each other. The perfluoropolyether oil (a) exhibits higher viscosity index, lower torque properties and lower abrasion resistance, although the heat resistance is not so good. On the other hand, the perfluoropolyether oil (b) exhibits lower volatility and improved oil film keeping properties at high temperatures, although the torque properties at low temperatures are not so good.
These straight-chain perfluoropolyether oils having different molecular weight and viscosity are mixed so that prominent properties of both components (a) and (b) can be retained in the thus formed base oil, thereby durability being exhibited together with torque properties at low temperatures. The base oil can be endowed with abrasion resistance and durability while retaining low temperature torque properties of the perfluoropolyether oil (a) by properly mixing it with the perfluoropolyether oil (b). A mixing rate of perfluoropolyether oils (a) and (b) may be variable depending on a condition to be applied, but is preferably 90/10 to 10/90.
It is surprising in view of the fact that a grease composition of higher torque is unexpectedly yielded when the base oil comprises only a straight-chain perfluoropolyether oil having intermediate molecular weight between both low and high molecular weight of components (a) and (b).
However, it is possible to some extent to obtain a low torque grease composition of the invention when such a straight-chain perfluoropolyether oil of intermediate molecular weight exists in the base oil in an amount of about 20% by mass or less of total weight thereof.
Polytetrafluoroethylene as a thickener (c) is prepared by copolymerizing tetrafluoroethylene in the presence of a molecular weight modifier to form a telomer which melting point is limited within the range of 310 to 330xc2x0 C. Tetrafluoroethylene is polymerized by, for example, solution polymerization, emulsion polymerization or suspension polymerization to form polytetrafluoroethylene having high molecular weight, i.e., number-average molecular weight of about 1000 to 500,000, which is then treated by thermal decomposition, r-ray irradiation, mechanical grinding, etc. The thus obtained polytetrafluoroethylene has an average primary particle diameter of 500 xcexcm or less, in general, and preferably about 0.05 to 20 xcexcm.
Polytetraethylene as a thickener (c) desirably comprises combined particles of larger and smaller particle diameters.
The thickener (c) preferably comprises (d) particulate component having a particle diameter of 0.5 xcexcm or less in an amount of 5 to 95% by mass and (e) particulate component having a particle diameter of 5 xcexcm or more in an amount of 95 to 5% by mass.
The particulate component (d) having a particle diameter of 0.5 xcexcm or less includes emulsion polymerized polytetrafluoroethylene having molecular weight of 100,000 to 200,000 and a primary particle diameter of 0.2 xcexcm, or solution polymerized one having molecular weight of 100,000 to 200,000 and a primary particle diameter of 0.1 xcexcm.
The particulate component (e) having a particle diameter of 5 xcexcm or more includes polymerized polytetrafluoroethylene.
Such polytetrafluoroethylene as a thickener is compounded to the grease composition in an amount of 1 to 60%, and preferably 5 to 30% by mass of the total composition.
The low torque grease composition of the invention may further comprise a rust preventing agent or corrosion inhibitor, if necessary.
The rust preventing agent includes, for example, fatty acid, fatty acid soap, fatty acid amine, alkylsulfonate, oxidized paraffin, polyoxyalkyl ether, sodium sulfonate, barium sulfonate, potassium sulfonate, calcium sulfonate, alkylnaphthalene, sodium nitrite, sodium nitride and the like. The corrosion inhibitor includes, for example, benztriazole, benzimidazole, thiadiazole and the like.
As a method for preparing the lubricating grease composition of the invention is not restricted in particular, the present composition may be formed, for example, by mixing a predetermined amount of polytetrafluoroethylene and additives to a mixed oil of two kinds of perfluoropolyether and thoroughly kneading them by means of a three-roll or high pressure homogenizer.
Embodiments of the invention are summarized as in the following.
1. A low torque grease composition having dynamic viscosity (40xc2x0 C.) of 40 to 150 mm2/sec which comprises a base oil consisting of
(a) straight-chain perfluoropolyether oil having dynamic viscosity (40xc2x0 C.) of 25 mm2/sec or less and represented by the following general formula:
RfO(CF2O)p(C2F4O)q(C3F6O)rRf
wherein Rf is a perfluoro lower alkyl group and all of p, q and r is an integer and a sum thereof is an integer of 25 to 45 and
(b) straight-chain perfluoropolyether oil having dynamic viscosity (40xc2x0 C.) of 250 mm2/sec or more and represented by the following general formula:
RfO(CF2O)p(C2F4O)q(C3F6O)rRf
wherein Rf is a perfluoro lower alkyl group and p, q and r are an integer and a sum thereof is an integer of 100 to 200; and
(c) polytetrafluoroethylene as a thickener.
2. A low torque grease composition having dynamic viscosity (40xc2x0 C.) of 40 to 150 mm2/sec described in the above item 1 in which straight-chain perfluoropolyether oils of molecular structure represented by the following general formula:
RfO(CF2O)p(C2F4O)q(C3F6O)rRf
wherein Rf is a perfluoro lower alkyl group, all of p, q and r is an integer, r=0 and a sum of p+q is an integer of 25 to 200, are used as components (a) and (b).
3. A low torque grease composition having dynamic viscosity (40xc2x0 C.) of 40 to 150 mm2/sec described in the above item 1 or 2 in which a (c) polytetrafluoroethylene thickener comprises (d) particulate component having a particle diameter of 0.5 xcexcm or less in an amount of 5 to 95% by mass and (e) particulate component having a particle diameter of 5 xcexcm or more in an amount of 95 to 5% by mass.
4. A low torque grease composition having dynamic viscosity (40xc2x0 C.) of 40 to 150 mm2/sec described in any one of the above items 1 to 3 which comprises a straight-chain perfluoropolyether oil having dynamic viscosity (40xc2x0 C.) of 40 to 150 mm2/sec in an amount of 20% by mass of total base oil and represented by the following general formula:
RfO(CF2O)p(C2F4O)q(C3F6O)rRf
wherein Rf is a perfluoro lower alkyl group, all of p, q and r is an integer and a sum thereof is an integer of 50 to 80.
5. A low torque grease composition having dynamic viscosity (40xc2x0 C.) of 40 to 150 mm2/sec described in any one of the above items 1 to 4 in which a rust preventing agent and/or corrosion inhibitor is added.
6. A low torque grease composition having dynamic viscosity (40xc2x0 C.) of 40 to 150 mm2/sec described in any one of the above items 1 to 4 for the purpose of using for bearings of electric controlling throttle motor of cars.
7. A low torque grease composition having dynamic viscosity (40xc2x0 C.) of 40 to 150 mm2/sec described in any one of the above items 1 to 4 for the purpose of using for motor bearings of aircraft.
The invention will be further described in detail by the following examples, however it is not restricted by these examples.
Each perfluoropolyether oil used in a base oil and each thickener of the invention are as follows.
(Base Oil)
Perfluoropolyether represented by the general formula:
RfO(CF2CF2O)m(CF2O)nRf
Four kinds of perfluoropolyether components were as in the following:
A-1: dynamic viscosity (40xc2x0 C.) of 15 mm2/sec; m+n=35
A-2: dynamic viscosity (40xc2x0 C.) of 70 mm2/sec; m+n=60
A-3: dynamic viscosity (40xc2x0 C.) of 85 mm2/sec; m+n=70
A4: dynamic viscosity (40xc2x0 C.) of 320 mm2/sec; m+n=110
Of these perfluoropolyether, A-1 and A-4 were used as components (a) and (b) of the invention, respectively.
(Thickener)
B-1: emulsion polymerized polytetrafluoroethylene (molecular weight of 100,000 to 200,000 and primary particle diameter of 0.2 xcexcm)
B-2: solution polymerized polytetrafluoroethylene (molecular weight of 100,000 to 200,000 and primary particle diameter of 0.1 xcexcm)
B-3: suspension polymerized polytetrafluoroethylene (molecular weight of 50,000 to 100,000 and primary particle diameter of 13 xcexcm)
Of these thickeners, B-1 and/or B-2, were used as components (d) and B-3 were used as components (e) of the invention, respectively.


At least one vent hole is provided on an aerodynamically constructed covering part for the underside of a motor vehicle. A partial flow of the cold fresh air flows through the vent hole between the covering part and the roadway and is guided to a space which is situated above and accommodates assemblies and/or chassis parts. At least one suction device is provided on the covering part for carrying away the heated air situated in the space disposed above in the direction of the roadway.

This application claims the priority of German Application No.: 103 41 642.0 filed Sep. 10, 2003, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an aerodynamically constructed covering part for the underside of a motor vehicle, particularly a passenger car. The covering part has a vent hole through which a partial flow of the cold fresh air flowing through between the covering part and the roadway during the driving operation is guided to a space which is situated above and accommodates assemblies and/or chassis parts, such as the engine compartment and/or transmission space or the like. The partial flow cools the assemblies and/or chassis parts situated there.
Increasingly, the aerodynamic optimization of vehicles takes place at the underside of the vehicle. Here, it is endeavored to implement an underbody having a smooth-surface covering. However, these coverings have the disadvantage that covered areas heat up more intensely. The reason is the insufficient exchange between, on one hand, heated air in the engine compartment and transmission space and, on the other hand, fresh cooling air. The known vent holes permit the targeted feeding of cold fresh air.
A problem arises, however, when already heated outgoing air mixes with the fresh air provided for the cooling, or when incoming and outgoing air conduction devices have a faulty design or do not exist. Furthermore, the aerodynamic advantages of a smooth underbody are considerably impaired by conventional venting concepts.
From German Patent Document DE-AS 1 286 917, a passenger car is known which is equipped with an aerodynamically constructed covering part on its underside. A grille in the form of several slots is provided below the engine on the covering part for venting the engine compartment.
In this arrangement, during the driving operation, a partial flow of the cold fresh air guided through between the covering part and the roadway is conducted through the slots to the engine situated above.
However, German Patent Document DE-AS 1 286 917 does not contain any information as to how the air heated by the engine is discharged from the engine compartment.
It is an object of the invention to further develop an aerodynamically constructed covering part for the underside of a motor vehicle according to the initially mentioned type such that, when the aerodynamic potential of a smooth underbody is utilized, simultaneously the air flowing through the engine compartment and the transmission space is fed and carried away in a targeted and therefore efficient manner.
According to certain preferred embodiments of the invention, this object is achieved by providing an aerodynamically constructed covering part for the underside of a motor vehicle, particularly a passenger car. At least one vent hole is provided on the covering part, through which a partial flow of cold fresh air flowing through between the covering part and the roadway during the driving operation is guided to a space which is situated above and accommodates assemblies and/or chassis parts, such as the engine compartment and/or transmission space or the like. The partial flow cools the assemblies and/or chassis parts situated there, and at least one suction device is provided on the covering part for carrying away the heated air situated in the space disposed above in the direction of the roadway. The at least one suction device being arranged at a distance from the vent hole.
Other advantageous features of Preferred embodiments of the invention are described herein and the claims.
Important advantages achieved by means of the invention are that, as a result of the arrangement of at least one suction device on the covering part, the air circulating through the engine compartment and transmission space is divided in a defined manner into a cooling incoming-air conduction and an outgoing-air conduction carrying away the heated air. As a result of the spatially offset arrangement of the at least one suction device with respect to the vent hole, it is achieved that only cold fresh air is fed to the engine compartment and transmission space, whereas the heated air flows out laterally beside the vent hole and then flows along the underside of the vehicle and is carried away toward the rear.
The suction effect is created in certain preferred embodiments of the invention by aerodynamically optimized suction gills, which form a vacuum zone at the covering part. Viewed in the longitudinal direction of the vehicle, the transversely extending suction gills are arranged in a spaced manner behind one another and are set against the air flow guided through between the roadway and the covering part. The suction gills extend from the covering part downward in the direction of the roadway and have a blade-shaped cross-section. The shape and the position of the suction gills are adapted to the respective cooling task and have the advantage that the aerodynamic coefficients are impaired only insignificantly.
An embodiment of the invention is illustrated in the drawing and will be explained in detail in the following.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

Aerodynamically constructed covering part for the underside of a motor vehicle

Dr. Ing. h.c.F. Porsche Aktiengesellschaft


A compressor element of a screw compressor inlet side and an outlet side and two helical rotors, respectively a male rotor with a drive for the male rotor and a female rotor that is driven by the male rotor by means of synchronisation gearwheels with at least one synchronisation gearwheel on the male rotor, wherein the drive and synchronisation gearwheels of the male rotor are chosen such that, upon being driven with acceleration of the rotors without gas forces, the resulting mechanical drive force that is exerted by this drive and by this synchronisation gearwheel on the male rotor has an axial component that is directed from the outlet side to the inlet side and that the movement of the male rotor in the axial direction from the outlet side to the inlet side is fixed by means of a single axial single-acting or double-acting bearing.

Known compressor elements for the said type comprise a housing with an inlet for the gas on the inlet side and an outlet for the gas on the outlet side and two rotor chambers in which two helical rotors are mounted on bearings that mesh together when driven to compress the gas, respectively a male rotor with a drive gearwheel for driving the male rotor by a gearwheel transmission and a female rotor that is driven by the male rotor by means of synchronisation gearwheels with at least one synchronisation gearwheel on the male rotor and one synchronisation gearwheel on the female rotor, whereby the synchronisation gearwheels are generally designed such that, when driven, the male rotor rotates faster than the female rotor.
By driving the compressor element, chambers are formed between the two rotors that are filled with gas at the inlet, whereby upon the rotation of the rotors these chambers move from the inlet side to the outlet side and become increasingly smaller, such that the enclosed gas is compressed and which is delivered at a higher pressure to a downstream consumer network via a pressure pipe connected to the outlet.
Due to the compression, forces are exerted by the gases on the rotors that tend to push the rotors away from the outlet side in the direction of the inlet side.
The drive gearwheel on the male rotor is chosen such that when driven by the drive gearwheel a force is exerted with an axial component that is directed from the inlet to the outlet, thus oriented opposite to the axial component of the force exerted by the gas on the male rotor, so that this gas force is partially offset by the driving force of the drive gearwheel, so that the axial bearings are exposed to smaller forces.
The synchronisation gearwheels also exert a force on the rotors, whereby this force on the male rotor generally adds to the gas force on this rotor, while in the case of the female rotor this force counteracts the gas force.
When the compressor element is driven unloaded, in other words without compressed gas having to be supplied, the gas forces are non-existent or minimal, such that the composite forces of the drive gearwheel and the synchronisation gearwheels could tend to push the rotors in the opposite direction towards the outlet, in contrast to the loaded situation with the supply of compressed gas.
During dynamic transitional modes, forces can occur that push the rotors in the one or the other direction.
All this means that the direction of the composite forces that are exerted on the rotors depends on the mode, loaded or unloaded, and the fact that the situation is static or dynamic, such that in some circumstances these forces tend to push the rotors against the inlet end face of the housing on the inlet side, and in other circumstances against the outlet end face of the housing on the outlet side.
To prevent the rotors coming into contact with one of the two end faces of the housing, the rotors are generally axially fixed by two axial bearings, more specifically one on the inlet side and one on the outlet side, complemented with a radial bearing on either side of the rotors.
It is known to provide compressor elements of the screw type with means in the form of a spring or a plunger to exert an additional mechanical axial force or prestress force on each rotor, in order to relieve the bearings and/or to prevent, in the absence of gas forces in the unloaded mode, the rotors being pushed or pulled by the axial drive forces of the drive gearwheel and the synchronisation gearwheels against the housing. These means are generally built into the bearing cover, such that it must be made extra thick and heavy.
A disadvantage of such force means is that it detrimentally affects the costs of the compressor element and that in some circumstances it also increases the load on the bearings instead of offsetting them such that larger bearings are required.
If plungers are used as a force means, the exerted force can be controlled, but such a control entails extra costs, makes the compressor element more vulnerable to possible breakdowns and increases the size and mass of the bearing cover and therefore also the forces and vibrations on the housing of the compressor element.
The axle journal of the male rotor on which the drive gearwheel is mounted experiences a relatively high bending force due to the radial forces that are exerted by the drive gearwheel on it. This has the disadvantage that in certain extreme conditions the axial bearing of the male rotor that is mounted on this axle journal can tilt, which can lead to a limitation of the operating region of the compressor element.
The known compressor elements of the discussed type are outlet driven, which means that the gearwheel transmission with the drive gearwheel is on the hot outlet side of the compressor element, whereby the axial bearing on this side of the rotors is in contact with the less pure environment of the gearwheel transmission, which can affect their lifetime. This axial bearing is called the main bearing and its primary function is to retain the rotor concerned locally in the axial direction.
Due to a varying temperature gradient in the axial direction of the rotors as a function of the mode of the compressor element, changes also occur in the length of the shaft of the rotors, whereby different temperatures of the male and the female rotors lead to different length changes of the two rotors and thus a change in the mutual axial position of both synchronisation gearwheels. This mutual axial displacement of the synchronisation gearwheels, in the event of synchronisation gearwheels with oblique toothing, has the undesired effect that the synchronisation between the rotors changes with the temperature.
With the known outlet-driven compressor elements the synchronisation gearwheels are on the inlet side in other words on the opposite side of the rotor where the main bearing is located and thus at a relatively large distance from this main bearing, such that the synchronisation gearwheels experience a significant mutual axial displacement due to the differential length variations of the rotors as a result of varying temperature gradients, with the disadvantage that in the case of synchronisation gearwheels with oblique toothing, the synchronisation change between the male and the female rotor can be undesirably large.

Compressor element for a screw compressor and screw compressor in which such a compressor element is applied

ATLAS COPCO AIRPOWER, NAAMLOZE VENNOOTSCHAP


The disclosed technology can enable files to be stored with a networked environment. The files can be associated with information (e.g., properties) such as a file name, a file type, a date/time at which a respective file was last accessed, a number of times a respective file was accessed, data representing the contents of a respective file, and other information. Based at least in part on analyzing the information, the disclosed technology can select or identify a file and/or a file property (e.g., a file type) that the disclosed technology predicts to be most relevant to the user. The disclosed technology can then recommend applications based at least in part on the selected or identified file and/or file property (e.g., file type).

Software applications (also known as simply "applications" or "apps") are becoming ubiquitous in all aspects of modern life. People use applications on their computing devices every day as mobile applications are growing in number and in function. For example, some users have applications to add photographic effects to the pictures they take. Some users have mobile apps to write, edit, and view documents while traveling on business. Other apps allow multiple users to communicate with one another. There are also gaming apps for users who like to play computer games on their computing devices. In fact, many computing device platforms have application marketplaces that provide applications for a wide variety of purposes. Users can access the application marketplaces to download, install, and use various apps.
With the increasingly large number of app choices, it can be difficult to determine which apps may be relevant and of interest to a particular user. In some cases, even the user may not know which apps are relevant or of interest to him/her. Determining which apps to present to the user can often be an inaccurate or imprecise task. Presenting apps of little or no interest to the user can be inefficient in terms of utilizing computing resources and can also reduce the overall satisfaction of the user experience associated with acquiring and using apps.

Application recommendation using stored files


An adapter for mounting at least one skid-steer loader attachment onto an excavator arm includes a mounting mechanism having a lower edge, an upper edge and a lip extending outwardly therefrom, the lip receiving an upper lip of such at least one skid-steer loader attachment for locking thereto. The mounting member is adapted with a pair of aligned first notches, a pair of aligned second notches and a pair of apertures for coupling onto a free end of such excavator arm in a conventional semi-permanent manner. A pair of locking assemblies are provided selectively engaging and releasing a lower edge of such at least one skid-steer loader attachment.

As is generally well known in the art, skid-steer loaders and excavators, particularly known as mini excavators, use attachments to perform various material handling and earth moving tasks. Presently, the attachments used on the skid-steer loaders cannot be interchanged with the attachments used on mini excavators due to different mounting requirements. Therefore, users must often transport both types of equipment to work sites where the mini excavator in combination with attachments presently used for skid-steer loaders would be required. Or, users are forced to purchase two sets of attachments for a particular task when they would like to transport only the mini excavator.

Adapter for mounting skid-steer loader attachments onto an excavator arm