7,500 research outputs found
Direct combination: a new user interaction principle for mobile and ubiquitous HCI
Direct Combination (DC) is a recently introduced user interaction principle. The principle (previously applied to desktop computing) can greatly reduce the degree of search, time, and attention required to operate user interfaces. We argue that Direct Combination applies particularly aptly to mobile computing devices, given appropriate interaction techniques, examples of which are presented here. The reduction in search afforded to users can be applied to address several issues in mobile and ubiquitous user interaction including: limited feedback bandwidth; minimal attention situations; and the need for ad-hoc spontaneous interoperation and dynamic reconfiguration of multiple devices. When Direct Combination is extended and adapted to fit the demands of mobile and ubiquitous HCI, we refer to it as Ambient Combination (AC) . Direct Combination allows the user to exploit objects in the environment to narrow down the range of interactions that need be considered (by system and user). When the DC technique of pairwise or n-fold combination is applicable, it can greatly lessen the demands on users for memorisation and interface navigation. Direct Combination also appears to offers a new way of applying context-aware information. In this paper, we present Direct Combination as applied ambiently through a series of interaction scenarios, using an implemented prototype system
Nod1 signaling overcomes resistance of S. pneumoniae to opsonophagocytic killing
Airway infection by the Gram-positive pathogen Streptococcus pneumoniae (Sp) leads to recruitment of neutrophils but
limited bacterial killing by these cells. Co-colonization by Sp and a Gram-negative species, Haemophilus influenzae (Hi),
provides sufficient stimulus to induce neutrophil and complement-mediated clearance of Sp from the mucosal surface
in a murine model. Products from Hi, but not Sp, also promote killing of Sp by ex vivo neutrophil-enriched peritoneal
exudate cells. Here we identify the stimulus from Hi as its peptidoglycan. Enhancement of opsonophagocytic killing
was facilitated by signaling through nucleotide-binding oligomerization domain-1 (Nod1), which is involved in
recognition of γ-D-glutamyl-meso-diaminopimelic acid (meso-DAP) contained in cell walls of Hi but not Sp. Neutrophils
from mice treated with Hi or compounds containing meso-DAP, including synthetic peptidoglycan fragments, showed
increased Sp killing in a Nod1-dependent manner. Moreover, Nod1-/- mice showed reduced Hi-induced clearance of Sp
during co-colonization. These observations offer insight into mechanisms of microbial competition and demonstrate
the importance of Nod1 in neutrophil-mediated clearance of bacteria in vivo
Liquid Crystalline Thermosets from Ester, Ester-imide, and Ester-amide Oligomers
Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystaloligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oli-gomers are stable forup to an hour in the melt phase. They are highly processable by a variety of melt process shape forming and blending techniques. Once processed and shaped, the end-capped liquid crystal oigomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures
Resin infusion of layered metal/composite hybrid and resulting metal/composite hybrid laminate
A method of fabricating a metal/composite hybrid laminate is provided. One or more layered arrangements are stacked on a solid base to form a layered structure. Each layered arrangement is defined by a fibrous material and a perforated metal sheet. A resin in its liquid state is introduced along a portion of the layered structure while a differential pressure is applied across the laminate structure until the resin permeates the fibrous material of each layered arrangement and fills perforations in each perforated metal sheet. The resin is cured thereby yielding a metal/composite hybrid laminate
Polyimide foams
A fully imidized, solvent-free polyimide foam having excellent mechanical, acoustic, thermal, and flame resistant properties is produced. A first solution is provided, which includes one or more aromatic dianhydrides or derivatives of aromatic dianhydrides, and may include one or more aromatic diamines, dissolved in one or more polar solvents, along with an effective amount of one or more blowing agents. This first solution may also advantageously include effective amounts respectively of one or mores catalysts, one or more surfactants, and one or more fire retardants. A second solution is also provided which includes one or more isocyanates. The first and second solutions are rapidly and thoroughly mixed to produce an admixture, which is allowed to foam--in an open container, or in a closed mold--under ambient conditions to completion produce a foamed product. This foamed product is then cured by high frequency electromagnetic radiation, thermal energy, or a combination thereof. Alternatively, the process is adapted for spraying or extrusion
Polyimide foams
A fully imidized, solvent-free polyimide foam having excellent mechanical, acoustic, thermal, and flame resistant properties is produced. A first solution is provided, which includes one or more aromatic dianhydrides or derivatives of aromatic dianhydrides, and may include one or more aromatic diamines, dissolved in one or more polar solvents, along with an effective amount of one or more blowing agents. This first solution may also advantageously include effective amounts respectively of one or mores catalysts, one or more surfactants, and one or more fire retardants. A second solution is also provided which includes one or more isocyanates. The first and second solutions are rapidly and thoroughly mixed to produce an admixture, which is allowed to foam?in an open container, or in a closed mold?under ambient conditions to completion produce a foamed product. This foamed product is then cured by high frequency electromagnetic radiation, thermal energy, or a combination thereof. Alternatively, the process is adapted for spraying or extrusion
Liquid crystalline thermosets from ester, ester-imide, and ester-amide oligomers
Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end-capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs
Metal/fiber laminate and fabrication using a porous metal/fiber preform
A metal/fiber laminate has a plurality of adjacent layers. Each layer is porous and includes an arrangement of fibers. At least one of the layers has its fibers coated with a metal. A polymer matrix permeates each such arrangement
Method for Molding Structural Parts Utilizing Modified Silicone Rubber
This invention improves upon a method for molding structural parts from preform material. Preform material to be used for the part is provided. A silicone rubber composition containing entrained air voids is prepared. The silicone rubber and preform material assembly is situated within a rigid mold cavity used to shape the preform material to die desired shape. The entire assembly is heated in a standard heating device so that the thermal expansion of the silicone rubber exerts the pressure necessary to force the preform material into contact with the mold container. The introduction of discrete air voids into the silicone rubber allows for accurately controlled pressure application on the preform material at the cure temperature
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