Roughly described, arrayed waveguide grating apparatus includes one or more input and/or output waveguides which are shaped and oriented such that optical energy communicated with the waveguide array is, within a distance of no more than 1 mm into the mouth of the waveguide, directed substantially in-line with the optical centerline of the waveguide. In one embodiment, the waveguides are shaped and oriented such that the optical energy enters or exits the waveguide substantially-line with the optical centerline of each waveguide. In another embodiment the waveguides are shaped and oriented such that optical energy is, at the mouth of each waveguide, directed off-axis, and the waveguide includes mode conversion means such that optical energy is directed substantially in-line with the optical centerline within a distance of no more than 1 mm into the mouth of the waveguide. The mode conversion means may, for example, include a non-adiabatic lateral optical centerline shift.

The present invention relates to arrayed waveguide gratings (AWGs), and more particularly to AWG arrangements with reduced channel passband asymmetry.
AWGs, sometimes also known as "phasars" or "phased arrays", are well known components in the optical communications network industry. An AWG is a planar structure comprising an array of waveguides arranged side-by-side which together act like a diffraction grating. AWGs can be used as multiplexers and as demultiplexers, and a single AWG design can commonly be used both as a multiplexer and demultiplexer. The construction and operation of such AWGs is well known in the art. See for example, "PHASAR-based WDM-Devices: Principles, Design and Applications", M K Smit, IEEE Journal of Selected Topics in Quantum Electronics Vol. 2, No. 2, 20 Jun. 1996, and U.S. Pat. No. 5,002,350 and WO97123969, both incorporated by reference herein.
FIG. 1 illustrates the layout of a conventional AWG. It comprises a substrate ("die", "chip") 100 supporting one or more input optical waveguides 110 delivering optical energy into an "input slab" region 112. The slab region is a planar waveguide which confines the input optical energy in only the vertical dimension; the energy is permitted to spread transversely without restriction. The input slab is sometimes referred to herein as an "input free space region", or an "input free propagation region". Note that despite the implication of these terms, energy spreads freely in these regions only in the transverse dimension; it remains confined vertically.
An image of the input optical energy (or an interference pattern, if there is more than one input optical waveguide) is developed on the far boundary 114 of the input free space region 112. At this boundary the light enters the input end 116 of a waveguide array 118 which consists of tens or hundreds of individual waveguides. The array waveguides are of lengths which increase linearly across the array, each waveguide having a length which differs from its nearest adjacent waveguide by a value ΔL.
Optical energy exits the waveguide array 116 at an output end 120 thereof, and delivers the light into an "output slab" region 122. Like the input slab, the output slab region is a planar waveguide which confines the input optical energy in only the vertical dimension. The energy is permitted to spread transversely without restriction, and for that reason the output slab is sometimes referred to herein as an "output free space region", or an "output free propagation region". In some embodiments the input and output free space regions overlap each other such that the input and output beams cross each other.
A diffraction pattern is developed on the far boundary 124 of the output free space region 122, where the light enters a set of one or more output optical waveguides 126. The structure can be used as a demultiplexer if there is only one input waveguide 110 and more than one output waveguide 126; in this case information can be carried on multiple channels (wavelengths) in the single input waveguide and the channels are separated out by the AWG for delivery into the different output waveguides. The structure can also be used as a multiplexer if operated in reverse. It can furthermore be used as a router if there are multiple input waveguides 110 and multiple output waveguide 126.
A problem that arises in AWG designs is that the passband spectrum of a given channel often can be asymmetrical in shape. Depending on the shape of the filter curve—"flat top" or "Gaussian"—the asymmetry may manifest itself in various forms. FIG. 2 illustrates this asymmetry for an AWG with flattened wavelength response (a so-called "Flat top" AWG). It can be seen that the passband asymmetry is most visible at the top of each filter passband shape, which appears slanted instead of flat. A typical example is shown more symbolically in FIG. 3. The response shown in FIG. 2 is from a 16×50 GHz Cyclic flat top AWG. It can be seen that the tilting of the top of the filter shape varies as a function of the channel number (i.e. as a function of wavelength).
The asymmetry referred to herein is asymmetry of the response about the intended center wavelength of a given channel. This asymmetry can be quantified in a number of different ways, but for purposes of the present description, for flat top devices, we quantify it in dB/nm as the slope of a straight line through two points spaced evenly around the central wavelength of the channel (see FIG. 3). This slope is sometimes referred to herein as the "tilt" of the response curve for the particular channel. For the spectrum shown in FIG. 2 the corresponding asymmetry values are given in FIG. 4. It can be seen that the asymmetry in this case varies from approximately −4 dB/nm to approximately 4 dB/nm.
For arrayed waveguide gratings with a Gaussian filter shape (Gaussian AWGs), the "tilt" is not evident in the response curve for a particular channel. Instead, asymmetry manifests itself as a channel dependent wavelength shift of the channel positions. FIG. 5 illustrates the response of a particular channel in a Gaussian AWG. The dotted line in FIG. 5 illustrates the intended (ideal) response curve and the solid line illustrates the response curve in which the asymmetry is included. The center wavelength shift arising due to the asymmetry is indicated as δλ. Again, while a number of different ways can be used to quantify the asymmetry for Gaussian AWGs, for purposes of the present discussion it is quantified as equal to the channel dependent wavelength shift. The asymmetry for an example Gaussian AWG is shown in FIG. 6. The device represented in this figure is a 40×100 GHz Gaussian AWG. On the horizontal axis the values 5 and 44 for CHANNEL_ID correspond with ITU frequencies of 192.1 THz and 196.0 THz respectively. On the vertical axis the difference between the channel positions and the ITU frequencies is given in nm. It can be seen that the asymmetry in this case varies from about −0.005 nm to about 0.005 nm.
It would be desirable to reduce or eliminate the channel passband asymmetry observed in conventional AWGs.

Arrayed waveguide grating with reduced channel passband asymmetry


The present invention provides a color material and a silver halide color photographic light-sensitive material, particularly, a color material and a silver halide color photographic light-sensitive material which are excellent in a coloring capability, processing stability, dye image fastness and a white background. This invention is characterized by containing at least one type of compounds represented by formula (A) in at least one layer on a reflective or transparent support

Silver halide color photographic light-sensitive material has been generally utilized as a material to provide high quality images of stable quality at low cost, and user's demands for higher image quality and more stable quality are more and more increasing. With respect to request for higher image quality, improvements in such as color reproducibility, tone reproducibility, a white background, fastness of a dye image and sharpness have been desired, and with respect to more stable quality, improvements in such as manufacturing stability of a light-sensitive material, stability during aging storage in an unexposed state and a capability variation at the time of processing are required. In particular, in accordance with a trend of rapid processing and decreased replenishing quantity in recent years, improvement of stabilized capabilities against variation of the processing in the market is still more strongly required.
With respect to request for a higher image quality, a cyan dye forming coupler of a pyrazolotriazole type, which overcomes a defect of absorption characteristics of a phenol type or naphthol type cyan dye coupler, has been proposed, however, there has been a problem of inferior light fastness of an image dye formed from a cyan dye forming coupler of a pyrazolotriazole type.
To overcome this problem, an improvement technique by a dye image stabilizer has been studied, and such as phenol type compounds, amine type compounds or phenylether type compounds are disclosed (for example, refer to Patent Documents 1-3).
However, in the case of employing these techniques, it has been proved that although fading by light of an image dye formed from a cyan dye forming coupler of a pyrazolotriazole type is decreased, generated may be a problem that bleeding of a dye image and an inter-layer transfer of a coupler due to an increased oil-soluble component incorporated with addition of a dye image stabilizer and a quality defect of increased variation of a white background depending on various processing in the market.
The present invention has been made in view of the above described background.                Patent Document 1: JP-A 9-50101 (hereinafter, JP-A refers to Unexamined Japanese Patent Application Publication)        Patent Document 2: JP-A 9-230553        Patent Document 3: JP-A 2001-356456

Color material and silver halide color photographic light-sensitive material


A stator which may be employed in an electric rotating machine. The stator includes a stator winding which includes in-slot portions disposed in slots of a stator core. The in-slot portions are arrayed in each of the slots in a form of multiple layers aligned in a radial direction of the stator core. The stator winding is made up of a first winding and a second winding which are connected together through a joint. The first winding is defined by a portion of the stator winding between the joint and an end of the stator winding which is to be connected to an external. The second winding includes the in-slot portion placed within at least one of the slots as an outermost layer that is one of the layers placed most outwardly in the radial direction of the stator core. This results in a great decrease in leakage current.

1. Technical Field of the Invention
The present invention relates generally to a stator which may be used with an electric rotating machine and designed to minimize leakage current, and an electric rotating machine equipped with such a stator.
2. Background Art
Japanese Patent First Publication No. 2009-112186, assigned to the same assignee as that of this application, discloses an electric rotating machine equipped with a hollow cylindrical stator in which a plurality of slots are formed. The slots extend in an axial direction of the stator. The stator is equipped with a stator winding made of wire. The stator winding has in-slot portions and turned portions. The in-slot portions are disposed inside the slots. Each of the turned portions connects between two of the in-slot portions outside the slots.
As viewed in a transverse section of the stator, the in-slot portions are arrayed, like in FIG. 17, in the form of multiple layers aligned in a radial direction of the stator. In FIG. 17, in-slot portions 320a are laid to overlap each other within a slot 330 in the radial direction of a stator 300. In the case where the stator winding is a three-phase winding, it is usually made up of a U-phase winding, a V-phase winding, and a W-phase winding. Ends of the U-, V-, and W-phase windings are disposed outside the slots in the radial direction of the stator because they must be connected electrically to a controller. Portions of the stator winding which are close to the ends of the U-, V-, and W-phase windings are, therefore, disposed in the slots as outermost layers.
The electric potential developed at the stator winding will be described below. FIG. 18 is a schematic view which shows a typical star-connected stator winding made up of U-, V-, and W-phase windings. Such a stator winding is wound in the stator with portions (i.e., the in-slot portions) aligned in the radial direction of the stator within the slots. In FIG. 18, "A" indicates a winding portion closer to an end U of the stator winding. "B" indicates a winding portion of the U-phase winding closer to a neutral point N. If a joint X of the winding portions A and B lies just at the middle between the end U and the neutral point N, an average potential developed at the joint X will be, as demonstrated in FIG. 19, a one-half (½) of that developed at the end U. Thus, the winding portion A closer to the end U is higher in potential than the winding portion B. The same applies to ends V and W.
In the case where the stator winding is made of a flat wire (also called a rectangular wire), side surfaces of the in-slot portions 320a, as illustrated in FIG. 20, face the stator core 310, so that capacitors are created between each of the in-slot portions 320a and an inner wall of the slot of the stator core 310. The in-slot portions 320a arrayed within the slot in the radius direction will also be referred to below as a first to fourth layers starting from the outmost in-slot portion 320a. Locations where the first to fourth layers are disposed in the slot will be referred to below as a first, a second, a third, and a fourth layer positions.
FIG. 20 shows transverse cross-sections of the first to fourth layers within the slot of the stator core 310.
An electrostatic capacitance C1, as established by the in-slot portion 320a in the first layer position, is given byC1=C10+C11+C12
Similarly, capacitances C2 to C4, as created by the in-slot portions 320a in the second to fourth layer positions, are given byC2=C21+C22C3=C31+C32C4=C41+C42
FIG. 20 illustrates the transverse cross-section of each of the in-slot portions 320a as being rectangular since the stator winding is made of a flat wire. Actually, short sides of each of the in-slot portions 320a is much smaller than long sides thereof.
Accordingly, the capacitance C10 in FIG. 20 is much greater than the capacitances C11 to C42. Specifically, C10>>C11, C12, C21, C22, C31, C32, C41, C42.
The following relation is, therefore, met.C1>>C2,C3,C4
If average potentials at the in-slot portions 320a placed in the first and fourth layer positions are defined as V1, V2, V3, and V4, a leakage current that is a time-derivative of a total charge is expressed byΣdQ/dt=Σd(Ck·Vk)/dt(k=1,2,3,4)
In the case where the in-slot portion 320a of the stator winding placed in the outermost layer position (i.e., the first layer position) is close to the end of any of the U-, V-, and W-phase windings, the average potential V1 in the outermost layer position, as described above, will be high, thus resulting in an increased leakage current. This usually leads to the problem of the so-called radio noise.

Stator designed to minimize leakage current and electric rotating machine using same


Online retailers may provider various content to the electronic commerce website such as advertisements. Content on the electronic commerce website may be optimized by assigning attribution value to the content where the attribution values correspond to the influence the content may have on a customer's decision making. The attribution values may be calculated using one or more regression models.

The use of electronic commerce websites has increased in recent years, allowing online retailers to offer goods and services for sale through the electronic commerce website. A website for an online retailer may include one or more content pages for each category of items offered for order by the online retailer as well as content pages for individual items. Customers may interact with the online retailer's website via a browser executed by a computing device. Furthermore, customers of the online retailer may browse the website following any number of links or other navigational features including advertisements. When customers purchase items on the online retailer's website it may be difficult to determine the influence the content of the website may have had on the customer's decision. The online retailer may track customers' navigation of the website to determine what influence if any the content of the website had on the customer. The online retailer may attribute values to various content based on the influence the particular content had on the customer's decision making. The online retailer may then use the attributed value assigned to various content in order to determine content and placement on the online retailer's website.

Attribution modeling using regression analysis


The present invention relates to compositions and absorbent articles including compositions for protecting and enhancing the barrier function of the skin. The compositions can be applied to the bodyfacing surfaces of absorbent articles so that the compositions come into contact with the skin. The compositions of the invention have improved stability on the bodyfacing surfaces after processing. The compositions of the invention provide several benefits including prevention and alleviation of skin irritations associated with the use of absorbent articles. The compositions can include hydrophilic solvents, high molecular weight polyethylene glycols, fatty alcohols, surfactants, natural fats, natural oils, sterols or sterol derivatives and emollients.

The present invention relates to the inclusion of lipid-enriched, hydrophilic compositions with improved stability on the bodyfacing materials of disposable absorbent articles, such as diapers, training pants, adult incontinence products, underpants, feminine care products, nursing pads, wound dressings and similar articles having absorbent capacity. The present invention also relates to improving skin health by protecting and enhancing the barrier function of the skin through delivery of hydrophilic compositions from the bodyfacing materials of disposable absorbent articles to the skin. Prior to delivery to the skin, the compositions are stable on the bodyfacing materials. The compositions of the invention can also provide benefit to the barrier function of the skin when they are incorporated into other skin-contacting materials such as tissues, wet wipes and cosmetic cleansing or buffing pads.
The stratum corneum is the outer-most layer of the skin and is responsible for regulating skin water levels and functioning as a barrier against chemicals and other stress agents found in the environment. The complex arrangement of lipids in the intercellular space of the stratum corneum is responsible for the establishment of normal barrier function. Multi-layered structures of cholesterol, ceramides and fatty acids, as well as some other minor lipids, provide the major barrier to the transport of substances into or through the skin. The overall structure of the stratum corneum acts as the frontline barrier to the skin. The link between skin barrier function and skin health is apparent from the skin inflammation caused by lipid extraction from the skin. That is, when skin barrier function is impaired, the other layers of the skin can be injured and have a response to that injury in the form of inflammation.
In the area of skin health, it is known to apply lipid-containing compositions to the skin in order to enhance the barrier function of the stratum corneum. This approach is disclosed in U.S. Pat. No. 5,643,899 issued to Elias et al. on Jul. 1, 1997. For some time, those of skill in the art have believed that it is necessary to apply all three of the lipid components of the stratum corneum (cholesterol, ceramides and fatty acids) to the skin in order to replenish and repair the skin and in order to not affect the normal repair processes of the skin. In particular, ceramides are believed to be very important. In fact, the art teaches that if fewer than all three of the components are used in a skin composition, the composition could actually compromise or delay repair of the barrier.
In U.S. patent application Ser. No. 09/382,018 now U.S. Pat. No. 6,475,197 filed Aug. 24, 1999, various compositions for improving skin health are described, including compositions suitable for use in conjunction with absorbent articles. The compositions in patent application Ser. No. 09/382,018 were found to provide benefits for skin health. The compositions were described as containing a variety of potential components and, in some forms, the compositions included natural fats and oils, sterols and sterol derivatives, humectants and surfactants. These compositions have been found to improve skin health even though they do not necessarily include any ceramides. Efficacy without ceramides was unexpected. Though the exact mechanism of functionality was not known, one hypothesis was that strongly hydrophilic components of the compositions, including hydrophilic solvent and high molecular weight polyethylene glycols, provided an overall composition that attracted water and that acted as a carrier to bring the lipid components into the skin. The surfactant and humectant components were believed to emulsify the lipid components into the composition. Further, these compositions included fatty alcohols that, together with the high molecular weight polyethylene glycols, were used to solidify the overall composition and to minimize the migration of the compositions into the nonwoven materials of the absorbent articles.
Therefore, benefits and improvements to skin health have been observed when compositions containing the lipids naturally present in the stratum corneum are applied to the skin. Though the exact mechanisms are not known, one hypothesis is that the lipids being applied with the compositions are replenishing lipids that have been lost from the stratum corneum as a result of physical or biological insults. Another hypothesis is that the lipids being applied with the compositions are providing additional lipids to the stratum corneum resulting in better protection against insults. The stratum corneum of the skin is constantly exposed to physical and biological insults that could have a negative effect on barrier function.
Absorbent articles such as diapers, training pants, incontinence products and feminine care products are worn such that they are in direct contact with the skin of the wearer. An unavoidable consequence of the use of absorbent articles is that the skin is exposed more directly to various physical and biological insults. Consequently, the barrier function of the skin covered by the absorbent article is put at risk. In order to provide disposability, absorbent articles are primarily constructed of nonwoven materials. Even though nonwoven materials are engineered to have soft hand and drape, they rub against the skin and there is friction. Such friction constitutes one form of physical insult to the skin barrier. Friction against the skin barrier also occurs with the use of absorbent tissues and wipes. Absorbent tissue and wipe products are frequently used for cleansing the skin areas covered by absorbent articles. Absorbent tissue and wipe products are necessary for removing biological waste materials from the skin.
In addition to these physical insults, skin covered by absorbent articles is also frequently exposed to biological insults. Biological fluids, such as urine, feces, vaginal secretions and nasal secretions, may contain a variety of components that can damage the skin barrier. Examples of these components include proteases, lipases and bile acids. Once the skin barrier is compromised, these components, in addition to other constituents of biological fluids, can initiate or exacerbate inflammation of the skin.
Diaper dermatitis is a genre of skin conditions that, in large part, originate from impaired skin barrier function. Impairment of the skin barrier can result from a variety of factors, including: increased skin hydration due to the occlusion of the skin caused by diapers, enzymatic skin damage due to fecal and urinary enzymes, and physical damage caused by friction against the diaper surface and repeated cleaning of the skin with absorbent tissues or wet wipes.
Excessive hydration of the skin also has a negative effect on the skin barrier. The hydration level of diapered skin, for example, may reach between five to ten times that of undiapered skin. Frequent contact of diapered skin with urine may also contribute to increased skin hydration. Increased skin hydration disrupts skin lipid organization in the stratum corneum. This disruption may increase the permeability of the skin to irritants from feces and urine, thus increasing the risk of skin inflammation.
Disposable absorbent articles such as diapers, training pants, adult incontinence products, absorbent under pants, feminine care products and nursing pads have been used to absorb body fluids and leave the skin dry. Disposable absorbent articles of this type generally include a liquid impermeable backsheet member, an absorbent core or assembly, and a liquid permeable body facing or liner material. The body facing or liner material comes into contact with the wearer""s skin. While the body facing material is made of a soft, compliant material, the material rubs against the skin during use and may not leave the skin completely dry and free of the bodily fluids, such as solid or semi-solid waste, the absorbent article is trying to absorb. During frequent insults of bodily fluids and frequent use of disposable absorbent articles, the skin can become irritated and appear red and be sore to the touch.
Creams, lotions or ointments can be used to provide an artificial hydrophobic barrier on the skin and to treat skin conditions such as diaper rash. Application of these types of products to the skin is often messy and inconvenient. Often, these products are not used prophylactically and are only used when signs of diaper rash are visible.
Diaper liners and other bodyfacing materials may be treated with emollients, such as petrolatum, that can be transferred to the skin through normal diapering practices. Once transferred to the skin, diaper liner formulations may provide an artificial barrier against feces and urine. These formulations may require high concentrations of petrolatum to ensure sufficient transfer to the skin to provide a benefit. High concentrations of petrolatum can be messy, greasy to the touch, and may impair the fluid handling properties of an absorbent article, such as a diaper. The slow penetration of petrolatum into the skin can lead to smearing of the agent over the skin and onto clothes and other materials.
Formulations, such as those containing petrolatum, are applied to the bodyfacing materials of absorbent articles during manufacture. In order to process and apply the formulations to the bodyfacing materials, the formulations need to be in a semi-solid or fluid state. However, in order to have stability on the bodyfacing material after manufacture, the formulations need to be semi-solid or solid across a wide range of shipping and storage temperatures. Not all of the presently known formulations are sufficiently stable on the bodyfacing materials. Consequently, such formulations may transfer off of the bodyfacing material prematurely or the formulations may migrate away from the skin-facing surfaces of the materials.
Thus, what is needed is a topically effective composition delivered from a bodyside or bodyfacing material of an absorbent article that protects, maintains, recovers or otherwise benefits skin barrier function against physical damage and irritants in biological fluids. It would also be desirable to provide a topical composition delivered from a bodyside material of an absorbent article that absorbs into the skin, is non-greasy and cosmetically acceptable to the consumer. Additionally, it would be desirable to provide a topical composition having improved stability on the bodyside material of an absorbent article. Further, it would be desirable to provide a topical composition delivered from a bodyside material of an absorbent article that does not impair the waste containment functions of the absorbent article.
In response to the difficulties and problems discussed above, compositions and the use of those compositions on absorbent articles for improving the barrier function of the skin have been discovered. The compositions of the invention provide several benefits associated with barrier function including protecting, strengthening, restoring and repairing the skin barrier. While the compositions of the inventions can have a variety of applications, the compositions are particularly beneficial when used in conjunction with absorbent articles such as diapers, incontinence garments, feminine care products, training pants, diaper pants, nursing pads and wound dressings. Additionally, the compositions of the invention could also provide benefits when used in conjunction with tissue, pre-moistened wipe products and cosmetic cleansing and buffing pads. A further benefit of the compositions of the invention is that the compositions show improved stability during processing and application to an article. The purposes and advantages of the present invention will be set forth in and apparent from the description that follows, as well as will be learned by practice of the invention. Additional advantages of the invention will be realized and attained by the compositions and articles particularly pointed out in the written description and claims hereof, as well as from the appended drawings.
In one aspect, the present invention relates to an absorbent article that includes an outer cover, a bodyside liner, an absorbent body and a composition. The bodyside liner is typically liquid permeable and defines a bodyfacing surface. The bodyside liner is connected in a generally superposed relation to the outer cover. The absorbent body is located between the bodyside liner and the outer cover. The composition is on a portion or the entire bodyfacing surface of the bodyside liner. The composition can be generally solid or semi-solid. The composition may be in a variety of forms, including, but not limited to, emulsions, lotions, creams, ointments, salves, suspensions, encapsulations, gels and the like. The composition can be applied to the bodyside liner using a variety of techniques including foam application, spraying, slot coating and printing. The present invention also encompasses technology that would permit integration of the composition directly with fibers or other materials used to form the bodyside liner. The compositions can be applied to the bodyfacing surface in amounts of from about 0.1 grams per meter squared (g/m2) to about 30 g/m2.
The compositions of the invention could also be applied to or be present on other skin contacting surfaces of absorbent articles such as the waist and leg elastics and the containment flaps. The compositions can include from about 10 to about 90 percent by weight of one or more hydrophilic solvents. More specifically, the compositions can include from about 25 to about 75 percent by weight of hydrophilic solvents. Desirably, the compositions of the invention can include from about 30 to about 60 percent by weight of hydrophilic solvents. Hydrophilic solvents include, but are not limited to, water, propylene glycol, low molecular weight polyethylene glycols (molecular weights of less than 720 daltons and liquid at room temperature), methoxyisopropanol, PPG-2 propyl ether, PPG-2 butyl ether, PPG-2 methyl ether, PPG-3 methyl ether, dipropylene glycol propyl ether, dipropylene glycol butyl ether, dipropylene glycol, methyl propanediol, propylene carbonate, water soluble/dispersible polypropylene glycols, ethoxylated polypropylene glycol, glycerin, sorbitol solutions, hydrogenated starch hydrolysate, silicone glycols and mixtures of such compounds.
The compositions of the invention also include from about 5 to about 95 percent by weight of one or more high molecular weight polyethylene glycols having a molecular weight of at least about 720 daltons. More specifically, the compositions can include from about 10 to about 50 percent by weight of high molecular weight polyethylene glycols. Desirably, the compositions of the invention can include from about 15 to about 25 percent by weight of high molecular weight polyethylene glycols. The high molecular weight polyethylene glycols primarily function to provide the hydrophilic solvents and any active ingredients in solid form. In addition to providing a solid medium for the solvent, and reducing its tendency to migrate, the high molecular weight polyethylene glycols provide a tackiness to the hydrophilic composition that improves transfer to the skin of the wearer. As used herein, suitable high molecular weight polyethylene glycols include, but are not limited to, the following materials: polyethylene glycols having an average molecular weight of 720 daltons or greater, and the like, as well as mixtures thereof. These materials are not liquid at room temperature. Particularly suitable high molecular weight polyethylene glycols can have an average molecular weight of from 720 to about 1,840,000 daltons, more specifically from about 1400 to about 440,000 daltons, and still more specifically from about 1760 to about 10,570 daltons.
The compositions of the invention also include from about 1 to about 30 percent by weight of one or more fatty alcohols. More specifically, the compositions can include from bout 10 to about 25 percent by weight of fatty alcohols. Desirably, the compositions of the invention can include from about 15 to about 20 percent by weight of fatty alcohols. As used herein, suitable fatty alcohols include, but are not limited to, the following materials: alcohols having a carbon chain length of C14-C30 or greater, including cetyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, and mixtures thereof.
The compositions of the invention also include from about 1 to about 20 percent by weight of one or more emulsifying surfactants having an HLB range greater than 7 or a combination of low and high HLB surfactants that provide an HLB range greater than 7. More specifically, the compositions can include from about 2 to about 15 percent by weight of surfactants. Desirably, the compositions of the invention can include from about 3 to about 10 percent by weight of surfactants. Emulsifying surfactants are employed typically in cosmetic preparations to form emulsions of various components. The immiscible phase, such as an oil, is dispersed as droplets in the continuous phase, such as water or in this case the hydrophilic solvent. Suitable surfactants include, but are not limited to, Emulsifying Wax NF, Glyceryl Stearate, Glyceryl Stearate SE, Glycol Stearate, Glycol Stearate SE, Glycereth-20 Stearate, Glyceryl Behenate, Glyceryl Hydroxystearate, Glyceryl Laurate SE, Glyceryl Oleate, Glyceryl Oleate SE, Propylene Glycol Oleate, Propylene Glycol Oleate SE, Propylene Glycol Stearate, Propylene Glycol Stearate SE, Sorbitan Stearate, Sorbitan Trioleate, water dispersible metal soaps (Sodium Stearate), Behenyl Dimethicone Copolymers, Lauryl Methicone Copolymers, Cetyl Methicone Compolymers, Cetyl Dimethicone Copolymers, Stearyl Dimethicone Copolymers, Dimethicone Copolymers and mixtures there of.
The compositions of the invention also include from about 0.1 to about 30 weight percent of natural fats or natural oils. More specifically, the compositions can include from about 0.5 to about 20 percent by weight of natural fats or natural oils. Desirably, the compositions of the invention include from about 1 to about 10 percent by weight of natural fats, natural oils or mixtures of both. Natural fats and oils include fats, oils, essential oils, fatty acids, fatty alcohols, phospholipids and mixtures of these compounds. The natural fats and oils can be similar to the lipids that are present in healthy skin in order to mimic the naturally present lipids. Synthetic or synthetically modified fats and oils could potentially also be used if they functioned in the same manner as their natural counterparts. Examples of fats and oils include Avocado Oil, Apricot Oil, Babassu Oil, Borage Oil, Camellia Oil, Canola Oil, Castor Oil, Coconut Oil, Corn Oil, Cottonseed Oil, Evening Primrose Oil, Hydrogenated Cottonseed Oil, Hydrogenated Palm Kernel Oil, Maleated Soybean Oil, Meadowfoam Oil, Palm Kernel Oil, Peanut Oil, Rapeseed Oil, Safflower Oil, Sphingolipids, Sweet Almond Oil, Tall Oil, Lanolin, Lanolin Alcohol, Lauric Acid, Palmitic Acid, Stearic Acid, Linoleic Acid, Stearyl Alcohol, Lauryl Alcohol, Myristyl Alcohol, Behenyl Alcohol, Rose Hip Oil, Calendula Oil, Chamomile Oil, Eucalyptus Oil, Juniper Oil, Sandlewood Oil, Tea Tree Oil, Sunflower Oil, Soybean Oil, PROLIPID 141 blend (available from International Specialty Products of Wayne, N.J.) and mixtures thereof.
The compositions of the invention also include sterols, sterol derivatives or mixtures of both in an amount of from about 0.1 to about 10 percent by weight. Sterols and sterol derivatives include compounds such as xcex2-sterols with a tail on the 17 position and no polar groups, such as cholesterol, C10-C30 cholesterol/lanosterol esters, tall oil sterols, soy sterols, sterol esters and mixtures of these compounds. More specifically, the compositions include from about 0.5 to about 5 percent by weight of sterols, sterol derivatives or mixtures of both. Even more specifically, the compositions include from about 0.8 to about 3 percent by weight of the sterol compounds. Examples of suitable sterol compounds include cholesterol, sitosterol, stigmasterol, and ergosterol, as well as, C10-C30 cholesterol/lanosterol esters, cholecalciferol, cholesteryl hydroxystearate, cholesteryl isostearate, cholesteryl stearate, 7-dehydrocholesterol, dihydrocholesterol, dihydrocholesteryl octyidecanoate, dihydrolanosterol, dihydrolanosteryl octyldecanoate, ergocalciferol, tall oil sterol, soy sterol acetate, lanasterol, soy sterol, avocado sterols, xe2x80x9cAVOCADINxe2x80x9d (trade name of Croda, Ltd. in Parsippany, N.J.), sterol esters and mixtures thereof.
The compositions of the invention further include from about 0.1 to about 10 percent by weight of one or more emollients. More specifically, the compositions include from about 0.5 to about 5 percent by weight of emollient(s). Even more specifically, the compositions include from about 1 to about 5 percent by weight of emollient(s). Suitable emollients include petroleum based oils, petrolatum, vegetable oils, mineral oils, lanolin and its derivatives, fatty esters, glycerol esters and their derivatives, propylene glycol esters and their derivatives, alkoxylated carboxylic acids, alkyoxylated alcohols, fatty alcohols, alkyl methicones, alkyl dimethicones, phenyl silicones, alkyl trimethylsilanes, dimethicone and mixtures of such compounds.
The compositions of the invention can include the emollient and skin protectant, dimethicone. The dimethicone can be blended with the other components through the addition of water-based emulsions containing dimethicone such as emulsions having the trade designations xe2x80x9cDow Corning 1669 Emulsionxe2x80x9d and xe2x80x9cDow Corning 1664 Emulsionxe2x80x9d available from Dow Corning of Midland, Mich. The dimethicone can also be blended using a microencapsulated dimethicone such as are available from Lipo Technologies of Dayton, Ohio or from 3M of St. Paul, Minn. The dimethicone can also be added to the compositions of the invention in the form of an entrapped dimethicone. Dimethicone can be entrapped in xe2x80x9cPolytrapxe2x80x9d or xe2x80x9cMicrospongesxe2x80x9d as are available from Advanced Polymer Systems of San Franciso, Calif. The dimethicone can also be incorporated in the form of a dimethicone treated powder such as dimethicone-treated talc or dimethicone-treated zinc oxide as are available from KOBO of South Plainfield, N.J.
Optionally, the compositions of the invention may include from about 1 percent by weight to about 20 percent by weight of one or more viscosity enhancers or rheology modifiers. The viscosity enhancers and rheology modifiers can be added to increase the melt point viscosity of the compositions. Increasing the melt point viscosity gives better stability of the compositions on the bodyfacing materials of the articles. The viscosity enhancers and rheology modifiers also improve the stability of the composition at the xe2x80x9chot box carxe2x80x9d stability temperature of about 130xc2x0 F. (54.5xc2x0 C.). Suitable viscosity enhancers can include, but are not limited to, Actrylamides Copolymers, Agar, Gelatin, Water-Dispersable Metal Soaps, Butoxy Chitosan, Calcium Carboxymethyl Cellulose, Calcium Alginate, Carbomer, Carboxybutyl Chitosan, Carboxymethyl Chitosan, Carboxymethyl Dextran, Carboxymethyl Hydroxyethyl Cellulose, Cellulose Gum, DMAPA Acrylates/Acrylic Acid/Acrylonitrogens, Hectorite, Hydrated Silica, Hydroxyethyl Cellulose, Hydroxypropyl Guar, Hydroxypropyl Methylcellulose, Isobutylene/Sodium Maleate Copolymer, Kelp, Lithium Magnesium Silicate, Lithium Magnesium Sodium Silicate, Magnesium/Aluminum/Hydroxide/Carbonate, Magnesium Aluminum Silicate, Magnesium Silicate, Magnesium Trisilicate, Methoxy PEG-22/Dodecyl Glycol Copolymer, Metyl Cellulose, Metyl Hydroxyethylcellulose, Microcrystalline Cellulose, Montmorillonite, Nonoxynol Hydroxyethylcellulose, PEG Crosspolymer, Polyacrylate-3, Polyacrylic Acid, Polyethylene/isopropyl Maleate Copolymer, Polymethacrylic Acid, Polyvinyl Alcohol, PVP/Decene Copolymer, PVP Montmorillonite, Sodium Acrylates Copolymer, Sodium Acrylate/Vinyl Alcohol Copolymer, Sodium Acrylates/Vinyl Isodecanate Crosspolymer, Sodium Carboxymethyl Starch, Sodium Hydroxypropyl Starch Phosphate, Sodium Polyacrylate, TEA Alginate, TEA Carbomer, Xanthan Gum, Yeast Polysaccharides and mixtures thereof.
As will be described later in further detail, the compositions of the invention have been shown to enhance the barrier function of the stratum corneum of the skin. The presence of the compositions of the invention on the skin, when the skin is subjected to physical and biological insults, has been shown to be beneficial. Though the exact mechanism(s) is not known, it is possible that the compositions of the invention enhance the skin barrier because, upon transfer of the composition to the skin, the lipids (i.e., natural fats/oils, which contain non-essential and essential fatty acids, and the sterols) are readily available to penetrate into the stratum corneum and to help in the repair of the compromised natural barrier of the skin. If the natural barrier has not been compromised, the lipids provide a topical barrier to the penetration of harmful biological irritants found in feces, urine, menses and nasal discharge.
In addition to the components already described, the compositions of the invention may also include active ingredients such as those ingredients that may be useful for treating skin irritations such as diaper rash. Examples of such active ingredients include allantoin and its derivatives, aluminum hydroxide gel, calamine, cocoa butter, cod liver oil, dimethicone, kaolin and its derivatives, lanolin and its derivatives, mineral oil, petrolatum, shark liver oil, talc, topical starch, zinc acetate, zinc carbonate, zinc oxide and mixtures of these ingredients. Some of the ingredients listed as possible active ingredients for treating the skin can also be used as emollients.
In order to enhance or increase the function of the compositions of the invention, additional ingredients may be added. Examples of the classes of ingredients along with their functions include: antifoaming agents (reduce the tendency of foaming during processing); antimicrobial actives; antifungal actives; antiseptic actives; antioxidants (product integrity); antioxidants-cosmetic (reduce oxidation); astringents-cosmetic (induce a tightening or tingling sensation on skin); astringent-drug (a drug product that checks oozing, discharge or bleeding when applied to skin or mucous membrane and works by coagulating protein); biological additives (enhance the performance or consumer appeal of the product); colorants (impart color to the product); deodorants (reduce or eliminate unpleasant odor and protect against the formation of malodor on body surfaces); other emollients (help to maintain the soft, smooth and pliable appearance of the skin by their ability to remain on the skin surface or in the stratum corneum to act as lubricants, to reduce flaking and to improve the skin""s appearance); external analgesics (a topically applied drug that has a topical analgesic, anesthetic or antipruritic effect by depressing cutaneous sensory receptors, or that has a topical counterirritant effect by stimulating cutaneous sensory receptors); film formers (to hold active ingredients on the skin by producing a continuous film on skin upon drying); fragrances (consumer appeal); silicones/organomodified silicones (protection, tissue water resistance, lubricity, tissue softness); oils (mineral, vegetable and animal); natural moisturizing agents (NMF) and other skin moisturizing ingredients known in the art; opacifiers (reduce the clarity or transparent appearance of the product); powders (enhance lubricity, oil adsorption, provide skin protection, astringency, opacity, etc.); skin conditioning agents; solvents (liquids employed to dissolve components found useful in the cosmetics or drugs); and surfactants (as cleansing agents, emulsifying agents, solubilizing agents and suspending agents).
Ranges are used to describe the relative quantities of compounds in the compositions of the invention and ranges are used to describe the relative physical properties of the compositions of the invention. It is understood that the ranges are by way of illustration only and that one of skill in the art would recognize that the nature of the specific compositions dictates the levels to be applied to achieve the desired results. The levels of components are ascertainable by routine experimentation in view of the present disclosure.
The compositions of the invention typically have a melting point of from about 32xc2x0 C. to about 100xc2x0 C. Melting behavior in this range provides compositions that are relatively immobile and localized on the bodyfacing surface of the bodyside liner of the absorbent article at room temperature. Though relatively immobile and localized at room temperature, the compositions are also readily transferable to the wearer of the article at body temperature through natural rubbing or friction during wearing and through adhesion of the composition to the skin of the wearer. The compositions also maintain their integrity and are not completely liquid at elevated temperatures such as may be experienced during storage. Stability in a solid state at elevated temperatures is made possible, in part, by the melting point and rheology provided by the high molecular weight polyethylene glycol and the addition of viscosity enhancers/rheology modifiers, if needed, in the formulation. Desirably, the compositions of the invention are easily transferable to the skin by way of normal contact, including adhesion of the composition to the skin, wearer motion or body heat. Because the compositions are relatively immobilized on the bodyfacing surfaces of the articles, the quantities of the compositions necessary to provide the desired skin barrier benefits are reduced. In addition, special barrier or wrapping materials may not be necessary for the articles of the invention.
The compositions of the invention have viscosities that range from about 10 to about 10,000 centipoise as measured at a temperature of 60xc2x0 C. At 55xc2x0 C., the compositions have viscosities greater than about 200 centipoise. The compositions may also have a penetration hardness of from about 5 millimeters to about 365 millimeters at 25xc2x0 C. The compositions can have process viscosities of less than about 100 centipoise under shear and pressure.
The present invention is further directed to a method of applying a composition to a bodyfacing surface of a bodyside liner of an absorbent article. The method of the invention includes a step of heating a composition to a temperature above the melting point of the composition. The composition can have a melting point of from about 32xc2x0 C. to about 100xc2x0 C. The composition can include one or more hydrophilic solvents, one or more high molecular weight polyethylene glycols having a molecular weight of at least 720 daltons, one or more C14 to C30 fatty alcohols, one or more emulsifying surfactants having a combined HLB in a range greater than 7, natural fats or oils, one or more sterols or sterol derivatives and one or more emollients. The composition can also include one or more viscosity enhancers or rheology modifiers. The method further includes a step of applying the composition to the bodyfacing surface of a bodyside liner of an absorbent article. The bodyfacing surface is that surface of the absorbent article that comes into contact with the skin of the wearer of the absorbent article. Other components of the absorbent article besides the bodyside liner may come into contact with the skin of the wearer. The composition can also be applied to those components including the waist elastics, the leg elastics, containment flaps and any other components coming into contact with the skin. The composition can be applied to the bodyfacing surface using a variety of techniques including foam application, spraying, slot coating, printing or combinations of these application techniques. The method of the invention also includes a step of resolidifying the composition. The composition can be resolidified in a variety of ways including chilling, slow cooling, curing or a combination of these techniques. After resolidification, the composition typically has a static viscosity of greater than about 200 centipoise. Further, the composition can have a penetration hardness of from about 5 to about 365 millimeters at 25xc2x0 C. after the step of resolidification.
In another embodiment, the present invention is directed to a composition. While the composition may have other useful functions, the composition generally provides a benefit to the function of the skin barrier. The composition can include from about 10 to about 90 percent by weight of one or more hydrophilic solvents, or a mixture of hydrophilic solvents. The composition can also include from about 5 to about 95 percent by weight of one or more high molecular weight polyethylene glycols having a molecular weight of at least 720 daltons, or mixtures of such glycols. The composition further includes from about 1 to about 30 percent by weight of one or more C14 to C30 fatty alcohols, or a mixture of such fatty alcohols. The composition can also include from about 1 to about 20 percent by weight of one or more emulsifying surfactants, including oil-in-water surfactants, having a combined HLB with a range greater than 7, or mixtures of such surfactants. The composition can include from about 0.1 to about 30 percent by weight of one or more natural fats or oils, or the composition can include a mixture of one or more natural fats and oils. The composition can also include from about 0.1 to about 10 percent by weight of one or more sterols, sterol derivatives or mixtures of both sterols and sterol derivatives. An additional component of the composition of the invention can be from about 10 to about 10 percent by weight of one or more emollients. The composition can further include from about 1 to about 20 percent by weight of one or more viscosity enhancers or rheology modifiers.
The composition of the invention can have a melting point of from about 32xc2x0 C. to about 100xc2x0 C. depending on the function for which the composition is intended to be employed. If the composition is intended to be applied to an absorbent article, it may be desirable for the composition to have a melting point such that the composition is immobile at room temperature. Depending on the processing and handling to which the composition will be exposed, it may be beneficial for the composition to have a process viscosity of less than about 100 centipoise under shear and pressure. The composition can have a penetration hardness of from about 5 to about 365 millimeters at 25xc2x0 C. Examples of specific compounds for the hydrophilic solvent, high molecular weight polyethylene glycol, fatty alcohol, oil-in-water emulsifying surfactant/surfactant combination, fat/oil, sterol/sterol derivative, emollient and viscosity enhancer/rheology modifier components of the composition can be as described previously and as will be described herein.
In an additional embodiment, the present invention is directed to a method for improving skin barrier function of a skin surface of a user. The method can include a step of contacting the skin surface of a user with a bodyfacing surface of a liner material. The liner material may be any type of woven or non-woven material. More specifically, the liner material is of a material that is typically used for the bodyside liner of an absorbent article. The bodyfacing surface has a composition on it. The composition can include a hydrophilic solvent, a high molecular weight polyethylene glycol having a molecular weight of at least 720 daltons, a C14 to C30 fatty alcohol, an oil-in-water emulsifying surfactant having a combined HLB in a range greater than 7, natural fat or oil, a sterol or sterol derivative, an emollient and a viscosity enhancer/rheology modifier. More specifically, the composition can include from about 10 to about 90 percent by weight of hydrophilic solvent, from about 5 to about 95 percent by weight of high molecular weight polyethylene glycol, from about 1 to about 30 percent by weight of C14 to C30 fatty alcohol, from about 1 to about 20 percent by weight of oil-in-water emulsifying surfactant/surfactant combination, from about 0.1 to about 30 percent by weight of natural fats or oils, from about 0.1 to about 10 percent by weight of sterols or sterol derivatives, from about 0.1 to about 10 percent by weight of emollients and, optionally, from about 1 to about 20 percent by weight of viscosity enhancers/rheology modifiers.
The method can also include a step of maintaining the bodyfacing surface of the liner material in contact with the skin surface of a user for a sufficient amount of time to transfer the composition to the skin surface. For purposes of the method, a sufficient amount of time would be the amount of time necessary for enough of the composition to have been transferred so as to enhance the skin barrier. The method of the invention further includes a step of repeating contact of the skin surface with the bodyfacing surface of the liner material for a sufficient amount of time in order to have an improvement in the skin barrier function of the wearer""s skin. The repeated contact can occur by either applying additional composition to the bodyfacing surface of the liner material or by applying a new liner material having a full amount of the composition on the bodyfacing surface.
The absorbent articles, methods and compositions of the invention advantageously enhance the skin barrier in such a way not observed with conventional absorbent articles and compositions. Consequently, use of the absorbent articles and compositions of the invention enhance the skin barrier to protect against damage caused by physical and biological irritations. It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention claimed. The accompanying drawings, that are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the articles, methods and compositions of the invention. Together with the description, the drawings serve to explain the various aspects of the invention.

Hydrophilic compositions for use on absorbent articles to enhance skin barrier


A method for processing seismic data from a subsurface using least squares migration or wave equation migration velocity analysis over a cost function comprising a function of a matching filter by iteratively updating the reflectivity model velocity model to yield an updated reflectivity model or updated velocity model that matches the observed seismic data.

Seismic surveys of subsurface regions of the Earth generate seismic data sets that are analyzed to determine the geophysical properties of the subsurface regions. Inversion processes can be used to match models of the geophysical properties of the subsurface regions with the actually observed and recorded seismic data. These inversion processes include least squares migration and wave equation migration velocity analysis. These inversion processes attempt to match models of the subsurface region of interest with actual recorded seismic data from the same subsurface region through the maximization or minimization of a given cost function. These costs functions can have a connection with the estimation of the lag between seismic traces (in time, depth or any other spatial parameter). Therefore, the definition of the cost functions and accounting for this lag between the seismic traces are important in using recorded seismic data to determine the geophysical properties of a subsurface region of interest.
Regarding time lags between seismic traces, analysis of seismic surveys of a subsurface region of interest can generate two distinct datasets differing by a time difference, time lag or time shift. This time shift can be estimated by determining the location of the maximum of the cross-correlation between the two datasets over a certain window in time, possibly averaged across several traces. However, this approach does not define the time difference as a continuous function of the data samples, which is a desirable property for optimisation or when the stability of the estimate is a concern, e.g., two very similar maxima would not lead to estimates that jump from one to the other if even a tiny amount of noise is added. In addition, if the first dataset and the second dataset have a constant phase difference, e.g. two different acquisition methods having a π/2 phase difference, the maximum of the cross-correlation yields an incorrect answer as more zero-crossing points exist that indicate the time shift. Therefore, improved methods for estimating this time difference that can be used in formulating cost functions is desired.
With regard to the use of least squares migration (LSM), the classic papers are "Least-squares Crosswell Migration" by Schuster (1993) and "Least-squares Migration of Incomplete Reflection Data" by Nemeth et al. (1999). They first introduced the concept and applied it to cross-well and surface seismic data, respectively. LSM is a very computationally expensive process, which is seen in its evolution in the literature from using a Kirchhoff migration (Nemeth et al., 1999) to the more expensive but exact Reverse Time Migration (RTM) algorithm that uses the two-way wave equation ("Least-squares Migration of Multisource Data with a Deblurring Filter" by Dai et al., 2011). Some of the literature covers conventional amplitude matching LSM ("Least-squares Reverse-Time Migration" by Yao et al., 2012 and "Least-squares Reverse Time Migration: Towards True Amplitude Imaging and Improving the Resolution" by Dong et al., 2012), while others have adopted cross-correlative methods to overcome the more practical problems in the method associated with the application to real data ("A Stable and Practical Implementation of the Least-Squares Reverse Time Migration" by Zhang et al., 2013). Also, in "Practical aspects of Least-squares Reverse Time Migration" by Dong et al. (2013) using a matching filter to help with the practical problems in a LSM algorithm is addressed while the standard cost function based on the difference between the modeled data and the observed data in their LSM process is used.
Wave equation migration velocity analysis is a highly non-linear process. Hence having a more convex cost function is an important issue. This type of cost function has some connection with the estimation of lag in depth between traces. As such it makes bridges with classical migration velocity analysis where picked residual move out are used ("A Decade of Tomography" by Woodward et al., 2008), but with the benefit of not being based on picking and rays.
In general, the sinusoidal nature of seismic data means that any cost function based on the difference between observed and modeled traces can suffer from cycle skipping, causing many additional local minima to be formed in the cost function. The existence of many local minima in a cost function leads to complications in obtaining the global minima. Therefore, methods of using LSM and wave equation migration velocity analysis that avoid the problems of cycle skipping and provide a global minimum or maximum are desired. These methods could utilize cost functions that account for time lags between traces in recorded seismic data.

Seismic data processing using matching filter based cost function optimization


A fuel reservoir for a liquid fuel cell particularly useful for portable electronic devices or for a reformer, includes (a) a container defining a volume for holding a liquid fuel; (b) a wicking structure positioned within the volume and into which at least one portion of the liquid fuel wicks and from which said liquid fuel subsequently may be metered, such as by pumping; (c) a retainer to hold the wicking structure in a desired orientation within the container; and (d) an outlet for the liquid fuel that is in communication with the wicking structure. A method of dispensing liquid fuel and a method of assembling a fuel cartridge are also disclosed.

Electrochemical fuel cells convert reactants, namely fuel and oxidants, to generate electric power and reaction products. Electrochemical fuel cells generally employ an electrolyte disposed between two electrodes (an anode and a cathode). An electrocatalyst is needed to induce the desired electrochemical reactions at the electrodes. Liquid feed solid polymer fuel cells operate in a temperature range of from about 0° C. to the boiling point of the fuel, i.e., for methanol about 65° C., and are particularly preferred for portable applications. Solid polymer fuel cells include a membrane electrode assembly ("MEA"), which comprises a solid polymer electrolyte or proton-exchange membrane, sometimes abbreviated "PEM", disposed between two electrode layers. Flow field plates for directing the reactants across one surface of each electrode are generally disposed on each side of the membrane electrode assembly. There is typically a backing layer (or gas diffusion layer) between the flow field plate and the MEA.
A broad range of reactants have been contemplated for use in solid polymer fuel cells, and such reactants may be delivered in gaseous or liquid streams. The oxidant stream may be substantially pure oxygen gas, but preferably a dilute oxygen stream such as found in air, is used. The fuel stream may be substantially pure hydrogen gas, or a liquid organic fuel mixture. A fuel cell operating with a liquid fuel stream wherein the fuel is reacted electrochemically at the anode (directly oxidized) is known as a direct liquid feed fuel cell.
A direct methanol fuel cell ("DMFC") is one type of direct liquid feed fuel cell in which the fuel (liquid methanol) is directly oxidized at the anode. The following reactions occur:Anode: CH3OH+H2O→6H++CO2+6e−Cathode: 1.5O2+6H++6e−→3H2OThe hydrogen ions (H+) pass through the membrane and combine with oxygen and electrons on the cathode side producing water. Electrons (e−) cannot pass through the membrane, and therefore are collected and flow from the anode to the cathode through an external circuit driving an electric load that consumes the power generated by the cell. The products of the reactions at the anode and cathode are carbon dioxide (CO2) and water (H2O), respectively. The open circuit voltage from a single cell is about 0.7 to 1 volt. Several direct methanol fuel cells are connected in series to obtain greater voltage.
Other liquid fuels may be used in direct liquid fuel cells besides methanol—e.g., other simple alcohols, such as ethanol or ethylene glycol, or dimethoxymethane, trimethoxymethane, hydrazine and formic acid. Further, the oxidant may be provided in the form of an organic fluid having a high oxygen concentration—i.e., a hydrogen peroxide solution.
A direct methanol fuel cell may be operated on aqueous methanol vapor, but most commonly a liquid feed of a diluted aqueous methanol fuel mixture is used. It is important to maintain separation between the anode and the cathode to prevent fuel from directly contacting the cathode and oxidizing thereon (called "cross-over"). Cross-over results in a short circuit in the cell since the electrons resulting from the oxidation reaction do not follow the current path between the electrodes. To reduce the potential for cross-over of methanol fuel from the anode to the cathode side through the MEA, very dilute aqueous mixtures of methanol (for example, about 5 percent of methanol in water, wherein the methanol concentration is expressed in methanol weight as percent of the total weight of the aqueous mixture) are typically used as the fuel streams in liquid feed DMFCs.
The proton exchange membrane (PEM) is a solid, organic polymer, usually polyperfluorosulfonic acid, that comprises the inner core of the membrane electrode assembly (MEA). Commercially available polyperfluorosulfonic acids for use as PEM are sold by E.I. DuPont de Nemours & Company under the trademark NAFION®. Alternatively, composites of porous polymeric membranes impregnated with perfluoro ion exchange polymers, such as offered by W.L. Gore & Associates, Inc., can be used as the proton exchange membranes. The PEM must be hydrated to function properly as a proton (hydrogen ion) exchange membrane and as an electrolyte.
For efficient function of the fuel cell, the liquid fuel should be controllably metered or delivered to the anode side. The problem is particularly acute for fuel cells intended to be used in portable applications, such as in consumer electronics including cell phones, where the fuel cell orientation with respect to gravitational forces will vary. Traditional fuel tanks with an outlet at the bottom of a reservoir, and which rely on gravity feed, will cease to deliver fuel when the tank orientation changes. In addition, dipping tube delivery of a liquid fuel within a reservoir varies depending upon the orientation of the tube within the reservoir and the amount of fuel remaining in the reservoir. Accordingly, to facilitate use of liquid fuel cells in portable electronic devices, a liquid fuel reservoir that controllably holds and delivers fuel to a liquid fuel cell, regardless of orientation, is desired.
A liquid fuel reservoir containing a wicking member, such as a urethane foam, is disclosed in co-pending U.S. Non-Provisional patent application Ser. No. 10/183,943, filed Jun. 28, 2002.

Orientation independent liquid fuel reservoir


Device for setting of the position of the cylinders of a rolling mill whose gripping is regulated by hydraulic jacks. The device essentially comprises a tubular sleeve which surrounds a measuring rod, making no contact therewith, and moves in the same manner as the latter, being fixed to one of the elements of the hydraulic jack for gripping the cylinders of rolling mills, and sliding in an aperture pierced in the other element of the jack.

A rolling mill, particularly one intended for processing metal materials, comprises a cage within which are placed at least two cylinders, and often more than two, aligned vertically along a gripping plane. The product to be processed, for example a metal strip or bar, is constrained to pass between two working cylinders serving to reduce its thickness and connected for this purpose, either directly or via other cylinders called support cylinders, to one or more control members which determine their vertical displacement along the vertical uprights of the cage in order to adjust their spacing, when idle or under load, as a function of the thickness of the product being rolled, i.e., to effect appropriate gripping.
A rolling mill of the type called "quarto", for example, comprises two working cylinders bearing respectively on two support cylinders. In a rolling mill of the "sexto" types intermediate cylinders are interposed between the working cylinders and the support cylinders.
The cage of the rolling mill normally comprises two vertical uprights connected by a crosspiece on which the gripping means bear. Each cylinder is supported by a shaft rotating, at both of its ends, in bearings mounted in a piece forming a bearing block, called a "chock", and able to slide, in the gripping plane, within the corresponding upright of the cage.
The gripping of the cylinders can be effected by mechanical devices of the type having a movable screw and fixed nut, in which the screw is moved by a toothed wheel of a reducing motor assembly of conventional type. However, it is generally preferred to use a hydraulic gripping device comprising at least two hydraulic jacks placed at the level of the two uprights of the cage and bearing on one side on the upright and on the other side on the chock of the corresponding cylinder, for example the upper support cylinder in the case of a quarto rolling mill.
Each jack comprises a plunger piston forming a hydraulic piston, and a body surrounding the piston and forming a shell defining a chamber of variable volume which is fed with fluid under pressure, the piston and body being able to slide axially one relative to one another. The body can be fixed and the piston movable, or vice versa, depending on the embodiment. In the first case, the movable piston bears, with its end opposite the pressure chamber, on the corresponding chock, and in the second case it is the movable body which bears directly on the chock.
A hydraulic gripping device possesses numerous advantages relative to the former screw devices. In particular, the hydraulic gripping device makes it possible to take more rapid action and to compensate virtually instantaneously the yielding of the cage, i.e., the movement apart of the rolling cylinders brought about by the engagement between these cylinders of the product to be rolled.
Furthermore, some time ago, very efficient systems were developed for adjusting the gripping and also compensating the various deformations, such systems requiring simple and accurate monitoring of the displacements of the movable element of the jack and of the chock. For this purpose, use is made of position sensors connected to hydraulic and electro-hydraulic elements forming the control circuit of the hydraulic gripping device.
In order conveniently to effect and monitor the measurements, it is logical to place the position sensor outside the cage, above the upper part of the corresponding upright. The sensor is then connected to the chock, whose position it monitors by means of a measuring rod, of constant length, which runs in a bore made within the upright or the crosspiece. In order to effect the measurement with accuracy, it is preferable for the rod to be placed in the axis of the jack and, as its end has to be connected to the movable part of the jack, it is caused to pass successively, via suitable apertures, through the upper part of the upright of the cage and the first and then the second member of the jack, before reaching the chock to which it is fixed by an attachment piece. As the rod passes through the chamber of the jack, it is necessary to ensure sufficient leak-tightness to resist the very high pressures existing in the jack, and for this purpose use is generally made of gaskets forming a sealing joint and placed at two levels in the apertures for the passage of the rod made on the two elements of the jack. In the most common embodiments such gaskets are arranged in the actual wall of the two elements of the jack and the rod is in permanent friction against these gaskets.
However, the measuring rod must accurately transmit to the position sensor the displacements, even minimal displacements, of the chock in question, and it must furthermore possess sufficient lateral flexibility for the measurement not to be falsified by the stresses exerted on the chock.
The arrangement adopted for the assembly of the measuring rod must therefore simultaneously meet a number of conditions in order for the measurement to be performed with accuracy.
The arrangements used to date apparently gave satisfaction, but it has recently been found that the requirements of accuracy in setting the position of the cylinders had become such that any disturbances, even very minimal disturbances such as, for example, the friction exerted by the sealing gasket, were capable of influencing the measurement.

Device for setting the position of the cyclinders of a rolling mill


A device and method for triggering the smoke detection system on a vessel in response to a fire inside a container housed in the vessel by providing a fire detection system inside the container and generating artificial smoke outside of the container in response to detecting fire inside the container.

This application claims priority from U.S. Provisional Application Ser. No. 61/374,774 filed Aug. 18, 2010.
The present invention relates to fire protection, and, in particular, to a device and method for protecting against fire in a container or unit load device (ULD) in the cargo hold of a vessel, such as an aircraft, railcar, or ship.
Goods to be transported in a vessel, particularly goods to be transported via aircraft, are usually loaded into containers (typically referred to as unit load devices (ULD's)), which are then loaded onto the vessel, in order to facilitate and speed up the loading and unloading process. It is possible for something in a ULD to ignite, with the smoke and heat of the fire being contained in the ULD, until it suddenly and explosively breaks out of the ULD and into the cargo hold. At that point, the fire could spread rapidly, which would create a dangerous situation.
While vessels currently have fire alarm and protection systems, those systems often do not sense the presence of a fire that is contained inside a container or ULD, which means that a fire could be smoldering for quite a while before it is detected, and, by the time it is detected, it may be such a large fire that it is difficult or impossible to suppress. For that reason, it would be desirable to modify or add to the existing systems to make them more effective at detecting and suppressing fires in containers or ULDs. However, modifications to an aircraft typically require full approval and recertification by a number of agencies which may include the aircraft manufacturer, the Federal Aviation Administration, and the US Department of Transportation, among others. There is also a concern about adding weight to the aircraft due to the modification, the cost of the modification itself, and the time required to install, and eventually to test and maintain, the modification.
It would be desirable to provide a device and method for automatically suppressing a fire inside a container (such as a ULD) while simultaneously alerting the fire alarm systems of the vessel, preferably without tying in electrically or mechanically, or otherwise in any way modifying the aircraft such that recertification is required. It would be preferable for such an automatic fire suppression and alarm system to be a totally passive system requiring no outside power (again, no tying into the aircraft systems) and no self-contained electrical power supply which has to be charged and which could, itself, be an ignition source.

Method for detecting and suppressing fire in a container


A mobile communication device includes a housing, a processing module installed inside the housing for controlling the mobile communication device, a power supply module for supplying the electric power of the mobile communication device, a first connecting port installed on the housing and connected to the power supply module for outputting voltage transmitted from the power supply module, and a diathermic module connected to the first connect port including an electrode pad for providing an electrical treatment according to the voltage transmitted from the first connect port.

1. Field of the Invention
The invention relates to a mobile communication device, and more particularly, to a mobile communication device with a diathermic function.
2. Description of the Prior Art
Mobile Phones have become highly popular electronic devices in recent years. The reduction in cost of the mobile phones has placed them in the affordable range of most people. Due to the rapid progress in technology, more functional and powerful mobile phones are constantly being invented. In order to meet costumers' demands, the mobile phone manufacturers often add many new functions and techniques to the mobile phone. For example, in the most modern mobile phones, a digital camera function and external keyboards are embedded in the mobile phone, both increasing convenience and enhancing the users' lifestyle.
Today's mobile phones utilize LEDs or OLEDs. Therefore, they need a DC-DC converter with a charge-pump function to raise the voltage of the mobile phone battery so that the above-mentioned devices can be driven. If the high voltage outputted by the DC-DC converter can be utilized to provide power to other devices (e.g. the new functions mentioned above), the value of the whole mobile phone will be increased.


A high-voltage tolerant power-rail ESD clamp circuit is proposed, in which circuit devices can safely operate under the high power supply voltage that is three times larger than their process limitation without gate-oxide reliability issue. Moreover, an ESD detection circuit is used to effectively improve the whole ESD protection function by substrate-triggered technique. Because only low voltage (1*VDD) devices are used to achieve the object of high voltage (3*VDD) tolerance, the proposed design provides a cost effective power-rail ESD protection solution to chips with mixed-voltage interfaces.

1. Field of the Invention
The present invention relates to an ESD clamp circuit and, more particularly, to a high-voltage tolerant power-rail ESD clamp circuit.
2. Description of Related Art
ESD protection is used to protect ICs from damage due to ESD events. When applied to a mixed-voltage IO interface, because there simultaneously exists more than two power supply voltages on this interface, both thin and thick gate oxide devices are usually simultaneously used with the considerations on product reliability, operating frequency, chip area, and so on. Though ICs with mixed-voltage circuits can be manufactured with both thin and thick gate-oxide devices by using extra process steps and additional mask layers, but they will increase the product cost and lower the production yield. Moreover, a thick-gate-oxide device has inferior device characteristics than that of the thin one, so that the operating frequency of chips will be limited. Therefore, if thin-gate-oxide devices can be applied under high operating voltages without reliability issue, the steps of manufacturing thick-gate-oxide devices can be saved.
Existing technologies relating to high-voltage-tolerant ESD protection can generally be categorized into three kinds. The first kind is an ESD protection element without gate-oxide structure. Because this kind of devices has no gate oxide, the gate oxide issue won't arise even if the operating voltage exceeds process limitation. But if this kind of device is used alone as the ESD protection element, the turn-on speed will be slower and the turn-on voltage will be higher during ESD, hence being unable to effectively protect internal circuits with thin gate oxides. If a forward-biased diode string is used as the ESD protection element, although a faster turn-on speed can be achieved, there will be a very large leakage current during operation under high temperatures because of parasitic pnp BJTs and Darlington beta gain. The second kind has a trigger circuit and an ESD clamp circuit of the primary ESD protection element. But this kind of devices can only tolerate a maximum power supply voltage, no more than two times of their device limitation. Most of the prior arts belong to this kind, e.g., an ESD protection element manufactured with 1.2-V devices but operated under 2.5-V power supply voltage. If the power supply voltage exceeds two times of their device limitation, the gate-oxide reliability issue of device will arise. Similar to the second kind, the third kind has a trigger circuit and an ESD architecture of the primary ESD protection element, but can tolerate a power supply voltage three times of their device limitation.
The above third kind of ESD (e.g., "High voltage power supply clamp circuitry for electrostatic discharge (ESD) protection" disclosed in U.S. Pat. No. 5,956,219) has a complicated circuit, and utilizes three stacked PMOS elements as the primary ESD path, hence having a larger turn-on resistance. In order to acquire a better ESD protection capability, a larger chip area is required, and different ESD elements cannot be matched for use, hence being less flexible. Although other ESD protection elements without gate oxide such as silicon-controlled rectifiers (SCRs) can operate under high power supply voltages without oxide gate reliability issue, these elements usually have a very slow turn-on speed and a too high turn-on voltage, and cannot effectively protect the chip circuits when used alone without being triggered by external circuits. Moreover, existing trigger circuits cannot operate under a power supply voltage three times of their device limitation.
The present invention aims to propose a high-voltage tolerant power-rail ESD clamp circuit to solve the above problems in the prior art.

High-voltage tolerant power rail electrostatic discharge clamp circuit


Novel diamondoid-based components that may be used in nanoscale construction are disclosed. Such components include rods, brackets, screws, gears, rotors, and impellers. Subassemblies (or subsystems) may comprise one or more diamondoid components. Exemplary subassemblies include atomic force microscope tips, molecular tachometers and signal waveform generators, and self-assembling cellular membrane pores and channels.

1. Field of the Invention
Embodiments of the present invention are generally directed toward the use of diamondoids as structural components in nanotechnology, and the combination of one or more structural components to form molecular subsystems. In particular, the present invention is directed toward exemplary diamondoids as rods, screws, brackets, and gears, and the combination of one or more components to make subsystems that include atomic force microscope tips, molecular tachometers and signal waveform generators, and self-assembling cellular membrane pores and channels.
2. State of the Art
Carbon-containing materials offer a variety of potential uses in nanoscale construction. A review of carbon's structure-property relationships has been presented by S. Prawer in a chapter titled "The Wonderful World of Carbon," in Physics of Novel Materials (World Scientific, Singapore, 1999), pp. 205-234. Prawer suggests the two most important parameters that may be used to predict the properties of a carbon-containing material are, first, the ratio of sp2 to sp3 bonding in a material, and second, microstructure, including the crystallite size of the material, i.e. the size of its individual grains. Elemental carbon has the electronic structure 1s22s22p2, where the outer shell 2s and 2p electrons have the ability to hybridize according to two different schemes. The so-called sp3 hybridization comprises four identical σ bonds arranged in a tetrahedral manner. The so-called sp2-hybridization comprises three trigonal (as well as planar) σ bonds with an unhybridized p electron occupying a π orbital in a bond oriented perpendicular to the plane of the σ bonds.
At the "extremes" of crystalline morphology are diamond and graphite. In diamond, the carbon atoms are tetrahedrally bonded with sp3-hybridization. Graphite comprises planar "sheets" of sp2-hybridized atoms, where the sheets interact weakly through perpendicularly oriented π bonds. Carbon exists in other morphologies as well, including amorphous forms called "diamond-like carbon," and the highly symmetrical spherical and rod-shaped structures called "fullerenes" and "nanotubes," respectively.
Diamond is an exceptional material because it scores highest (or lowest, depending on one's point of view) in a number of different categories of properties. Not only is it the hardest material known, but it has the highest thermal conductivity of any material at room temperature. It displays superb optical transparency from the infrared through the ultraviolet, has the highest refractive index of any clear material, and is an excellent electrical insulator because of its very wide bandgap. It also displays high electrical breakdown strength, and very high electron and hole mobilities.
Diamond is an attractive material for other reasons. At room temperature, the root-mean-square amplitude of vibration for diamond is as low as 0.002 nanometers, whereas for other materials this parameter is significantly higher. For example, the element lead (Pb) exhibits a root-mean-square amplitude of vibration of 0.028 nanometers. Low vibrational amplitudes are an important property for precision construction and operation of NEMS (nanoelectromechanical systems).
The microstructure of a diamond and/or diamond-like material further determines its properties, to the extent that microstructure influences the type of bonding content. As discussed in "Microstructure and grain boundaries of ultrananocrystalline diamond films" by D. M. Gruen, in Properties, Growth and Applications of Diamond, edited by M. H. Nazaré and A. J. Neves (Inspec, London, 2001), pp. 307-312, recently efforts have been made to synthesize diamond having crystallite sizes in the "nano" range rather than the "micro" range, with the result that grain boundary chemistries may differ dramatically from those observed in the bulk. Nanocrystalline diamond films have grain sizes in the three to five nanometer range, and it has been reported that nearly 10 percent of the carbon atoms in a nanocrystalline diamond film reside in grain boundaries.
A form of carbon not discussed extensively in the literature are "diamondoids." Diamondoids are bridged-ring cycloalkanes that comprise adamantane, diamantane, triamantane, and the tetramers, pentamers, hexamers, heptamers, octamers, nonamers, decamers, etc., of adamantane (tricyclo[220.127.116.11,7]decane), adamantane having the stoichiometric formula C10H16, in which various adamantane units are face-fused to form larger structures. These adamantane units are essentially subunits of diamondoids. The compounds have a "diamondoid" topology in that their carbon atom arrangements are superimposable on a fragment of an FCC (face centered cubic) diamond lattice.
Diamondoids are highly unusual forms of carbon because while they are hydrocarbons, with molecular sizes ranging in general from about 0.2 to 20 nm (averaged in various directions), they simultaneously display the electronic properties of an ultrananocrystalline diamond. As hydrocarbons they can self-assemble into a van der Waals solid, possibly in a repeating array with each diamondoid assembling in a specific orientation. The solid results from cohesive dispersive forces between adjacent C—Hx groups, the forces more commonly seen in normal alkanes. That diamondoids have unusual strength and rigidity as individual molecules is made clear from their means of isolation: they survive high-temperature pyrolysis that converts all other hydrocarbons materials in a petroleum feedstock to methane and graphitic carbon.
Buckminsterfullerene (C60), and related nanometer-sized carbon structures (nanotubes) have been applied in the construction of NEMS. Diamondoids have sizes comparable to that of buckminsterfullerene and properties that are complementary. Nanotribology studies have shown that the coefficient of friction of diamond can be over an order of magnitude less than that of buckminsterfullerene, making diamond a preferable material for extended operation of nanometer-sized devices where the contact between two surfaces is a key feature.
Diamond has been shown to be a highly desirable material for the construction of Micro-electrical mechanical (MEMS) micrometer-sized devices. Constructing MEMS out of diamond extends expected operational lifetimes by a factor of 10,000 over MEMs constructed of other materials, e.g., polysilicon. Diamond can similarly be expected to be a highly desirable material for construction of Nano-electrical mechanical systems (NEMS), nanometer-sized devices.
The use of "diamondoids" as structural components in nanoscale technologies has been discussed by K. E. Drexler in Nanosystems (Wiley, New York, 1992), pp. 253-272. Drexler states that the strength, stiffness, shape, and surface properties of nanoscale components determine what they can do. In this chapter, Drexler discusses components from a structural perspective, noting that while it is natural to focus on moving parts, much of a typical system has its mass in the form of a stiff housing. Gears, bearings, springs, screws, sliding rods, and motors should be pictured as being anchored to or embedded in an extended diamondoid structure, the structure tailored to support the components in functional positions with respect to one another.
Drexler was first to identify the qualities of diamondoid structures for construction of nanometer-sized devices. He envisioned complex nanometer-sized diamondoid objects, such as bearings, that are analogs of macroscopic machine parts, and calculated their properties using advanced computerized molecular simulations. This work has been extended by Merkle and others, but is still largely a theoretical projection due to a lack of actual materials and methods. The difficulty is that the diamondoid structures that were imagined would be virtually impossible to prepare using current technologies. Only one of the four possible diamondoids having four face-fused adamantane subunits (i.e., only one of the tetramantane isomers) has been synthesized to date, and then only with great difficulty.
Along similar lines, the concept of molecular manufacturing and molecular engineering has been reviewed by Z. Asfari and J. Vicens in a review article titled "Molecular Machines," J. of Inclusion Phenomena and Macrocyclic Chemistry, Vol. 36, pp. 103-118 (2000). Molecular manufacturing and molecular engineering are approaches to the development of general capabilities for molecular manipulation to produce new organic and biological materials manufactured atom by atom at the molecular level. The terms "molecular-size tinkertoy construction" and "molecular lego" have been used in the literature to characterize this branch of organic chemistry. And their review chapter, Asfari and Vicens described molecular-size systems exhibiting mechanical properties that may be interpreted in terms of classical mechanics. In other words, a molecular size system may be thought of as an assemblage of parts designed to transmit or modify the application of power, force, or motion to other parts of the system in a predetermined manner. The mechanical properties of these components are related to their geometries, their ability to thermally rotate around single bonds, steric effects amongst components of the system, and the manner in which forces are translated through the rigid architectures provided by the system. Examples of molecular-size systems reviewed by Asfari and Vicens include propellers, gears, beveled gears, toothed cogs, brakes, ratchets, turnstiles, pendulums, gyroscopes, rotors, impellers, and shuttles.
The importance of rotary motion in such nanoscale systems is brought to light in another review article titled "Rotary motion in single-molecular machines" by T. R. Kelly and J. P. Sestelo, in Molecular Machines and Motors, J.-P. Sauvage, ed. (Springer, Berlin, 2001), pp. 19-51. The chapter focuses on molecular systems that exhibit controlled or coordinated rotary motion, and emphasizes how such systems represent a reproduction of a variety of macroscopic mechanical devices on a molecular scale. Examples of such systems described by the authors include molecular gears, turnstiles, brakes, ratchets, and rotary motors.
Drexler's definition of the term "diamondoid" is broad in comparison to its use in the present patent. Nanosystems defines the term as a "strong, stiff, covalent solid with a dense, three-dimensional network of bonds." Drexler states that the diamondoid solids of most interest have compositions that include multivalent elements from the first row of the periodic table, such as boron, carbon, nitrogen, and oxygen, but may make substantial use of similar second row elements such as silicon, phosphorus, and sulfur, and limited use of monovalent covalent elements such as hydrogen, fluorine, and chlorine. Included in the definition of diamondoid materials are silicon carbide, alumina, silicon nitride, and tungsten, with the properties shown in Table I:
TABLE IProperties of diamondoid materials reported by DrexlerYoung's ModulusStrengthDensityMaterial(GPa)(GPa)(kg/m3)Diamond1050503,500SiC700213,200Al2O3532154,000Si3N4385143,100Tungsten350419,300
Drexler also points out that such diamondoid structures have a further advantage in that they are amenable to a description by molecular mechanical modelling, including the property stiffness.
Finally, Drexler states that it would be useful to "specify and characterize many small, regular structures useful as shafts, gears, and so forth; means for indexing and recovering designs are of comparable importance." What is needed is a selection of diamondoid materials that have been cataloged in terms of shape and dimensions.

Diamondoid-based components in nanoscale construction