Abstract: A seal-cover assembly for a structure including a first side and a second side opposing the first side. The seal-cover assembly includes a cap defining a recess, and an insert fixed to the cap within the recess to form a cover unit. The cover unit is configured to be secured to the first side of the structure. The seal-cover assembly includes a fastener configured to be disposed through the structure from the second side of the structure. The fastener is attached to the cover unit relative to the second side without accessing the first side of the structure. Additionally, an aircraft includes the structure and the seal-cover assembly as discussed above. Furthermore, a method of assembling the seal-cover assembly to the structure includes the cover unit secured to the first side of the structure such that an interior of the cover unit is inaccessible from the first side.

Abstract: Disclosed are memory encryption systems and methods that rotate encryption keys for robust resistance against side-channel-analysis (SCA)-based attacks on communication paths between an encryption engine within a trust boundary and an external memory component. A key data structure has a plurality of keys that are used to encrypt a plurality of memory blocks in the external memory. The memory blocks encrypted with the oldest key of the key data structure are identified. Encrypted data is read from the identified memory blocks. The encrypted data is decrypted from the identified memory blocks. The data is then re-encrypted using the selected key that is newer than the oldest key, and re-written to the identified memory blocks.

Abstract: Methods and structural gap filler for one up assembly of structures. Drilling debris generated between the first component and the second component during drilling of an injection hole are encapsulated by injecting a structural gap filler through the injection hole and between the first component and the second component.

Abstract: A protection seal cap for enclosing an end portion of a fastener which extends from a structure, which includes a cap member, which includes a sidewall that defines an interior space within the cap member. The sidewall forms a continuous wall member positioned within the cap member. The continuous wall member defines an opening providing access to the interior space. The continuous wall member is configured to create an interference compression fit between the end portion of the fastener and the continuous wall member.

Abstract: A cap system for enclosing a metallic fastener assembly extending through a structure, which includes a first securement mechanism positioned about a periphery of a nut member of the metallic fastener assembly, wherein the first securement mechanism comprises a plurality of continuous grooves which extend about the periphery of the nut member. The cap system further includes a cap member which includes a sidewall having an inner surface which defines a cavity dimensioned to receive the nut member and defines a second securement mechanism complementary configured to engage the first securement mechanism positioned about the periphery of the nut member. The cap system also includes an end of the sidewall of the cap member defines an opening which provides the nut member to have access into the cavity.

Abstract: A workpiece and associated method includes fabricating, employing an additive manufacturing process, a raw workpiece from aluminum alloy that includes silicon; heat-treating the raw workpiece to produce an intermediate workpiece, including subjecting the raw workpiece to a first temperature environment, wherein the first temperature environment agglomerates silicon particles disposed on a surface of the raw workpiece; cleaning the intermediate workpiece without removing the silicon particles agglomerated on the surface thereof; and applying a conversion coating onto the surface of the intermediate workpiece.

Abstract: A cap system for enclosing a metallic fastener assembly extending through a structure, which includes a first securement mechanism positioned about a periphery of a washer of the metallic fastener assembly wherein the first securement mechanism includes a first tab member extending in a direction transverse to a plane of a surface of the washer and a second tab member extending in a direction transverse to the plane of the surface of the washer spaced apart from the first tab member about the periphery of the washer. Cap system further includes a cap member which includes a sidewall having an inner surface which defines a cavity dimensioned to receive the washer and defines a second securement mechanism complementary configured to engage the first securement mechanism; and an end of the sidewall of the cap member defines an opening which provides the washer to have access into the cavity.

Abstract: An antimicrobial coating composition is disclosed. The antimicrobial coating composition also includes a polymer having a plurality of alkene units and a plurality of macroCTA polymer units. The composition also includes one or more reactive silanes, one or more wetting agents, and one or more solvents. A method for applying an antimicrobial coating composition is disclosed. The method for applying an antimicrobial coating composition may include contacting a polymer, one or more wetting agents, one or more solvents, and one or more reactive silanes with one another to prepare an antimicrobial coating composition, homogenizing the antimicrobial coating composition, applying the antimicrobial coating composition to a substrate, and allowing the antimicrobial coating composition to dry at ambient conditions.

Abstract: Disclosed are memory encryption systems and methods that rotate encryption keys for robust resistance against side-channel-analysis (SCA)-based attacks on communication paths between an encryption engine within a trust boundary and an external memory component. A key data structure has a plurality of keys that are used to encrypt a plurality of memory blocks in the external memory. The memory blocks encrypted with the oldest key of the key data structure are identified. Encrypted data is read from the identified memory blocks. The encrypted data is decrypted from the identified memory blocks. The data is then re-encrypted using the selected key that is newer than the oldest key, and re-written to the identified memory blocks.

Abstract: A seal-cover assembly for a structure including a first side and a second side opposing the first side. The seal-cover assembly includes a cap defining a recess, and an insert fixed to the cap within the recess to form a cover unit. The cover unit is configured to be secured to the first side of the structure. The seal-cover assembly includes a fastener configured to be disposed through the structure from the second side of the structure. The fastener is attached to the cover unit relative to the second side without accessing the first side of the structure. Additionally, an aircraft includes the structure and the seal-cover assembly as discussed above. Furthermore, a method of assembling the seal-cover assembly to the structure includes the cover unit secured to the first side of the structure such that an interior of the cover unit is inaccessible from the first side.

Abstract: A protective seal cap assembly for enclosing an end portion of a fastener extending through a structure, which includes a cap member. The cap member includes a sidewall which defines an opening and defines an interior space within the sidewall and aligned with the opening, wherein the sidewall defines a central axis. The cap member further includes at least one rib which extends away from an interior surface of the sidewall within the interior space and extends in a direction along the central axis of the cap member.

Abstract: A protection seal cap for enclosing an end portion of a fastener which extends from a structure, which includes a cap member, which includes a sidewall that defines an interior space within the cap member. The sidewall forms a continuous wall member positioned within the cap member. The continuous wall member defines an opening providing access to the interior space. The continuous wall member is configured to create an interference compression fit between the end portion of the fastener and the continuous wall member.

Abstract: A method for processing a raw workpiece into a final workpiece is described, wherein the raw workpiece includes a metallic structure including silicon particles dispersed therein. The raw workpiece is fabricated employing an additive manufacturing process, in one embodiment. The method includes heat-treating the raw workpiece to produce an intermediate workpiece, wherein the heat-treating includes subjecting the raw workpiece to a first temperature environment for a time period to produce an intermediate workpiece to form agglomerated silicon particles, wherein the agglomerated silicon particles are disposed on a surface of the raw workpiece. The method further includes removing the agglomerated silicon particles that are disposed on the surface of the intermediate workpiece.

Abstract: A cap system for enclosing a metallic fastener assembly extending through a structure, which includes a first securement mechanism positioned about a periphery of a nut member of the metallic fastener assembly, wherein the first securement mechanism comprises a plurality of continuous grooves which extend about the periphery of the nut member. The cap system further includes a cap member which includes a sidewall having an inner surface which defines a cavity dimensioned to receive the nut member and defines a second securement mechanism complementary configured to engage the first securement mechanism positioned about the periphery of the nut member. The cap system also includes an end of the sidewall of the cap member defines an opening which provides the nut member to have access into the cavity.

Abstract: A cap system for enclosing a metallic fastener assembly extending through a structure, which includes a first securement mechanism positioned about a periphery of a washer of the metallic fastener assembly wherein the first securement mechanism includes a first tab member extending in a direction transverse to a plane of a surface of the washer and a second tab member extending in a direction transverse to the plane of the surface of the washer spaced apart from the first tab member about the periphery of the washer. Cap system further includes a cap member which includes a sidewall having an inner surface which defines a cavity dimensioned to receive the washer and defines a second securement mechanism complementary configured to engage the first securement mechanism; and an end of the sidewall of the cap member defines an opening which provides the washer to have access into the cavity.

Abstract: A cap assembly for enclosing a metallic fastener which extends through a structure. The assembly includes a housing having an inner wall and an outer wall which extends about and is spaced apart from the inner wall defining a space positioned between the inner wall and outer wall. The assembly further includes a plunger member with a side wall portion secured to an end wall portion. The side wall portion of the plunger member has a thickness dimension smaller than a distance between the inner wall and the outer wall to position the sidewall portion of the plunger member within the space. With the side wall portion positioned within the space, the end wall portion is positioned in alignment with the inner wall and with an opening defined by and through the inner wall.

Abstract: A containment cap assembly for enclosing a metallic fastener extending through a structure includes an inner cap with a projection extending from an outer surface of the inner cap and an outer cap includes a first end which defines an opening and includes an inner surface which defines a first space within the outer cap in communication with the opening. A dimension of the opening and of the first space defined by the inner surface of the outer cap are each greater than a dimension defined by the outer surface of the inner cap such that with positioning the inner cap within the outer cap, a second space is defined between the outer cap and the inner cap. A slot of the outer cap extends first curvilinear direction such that the projection positioned within the slot moves along first curvilinear direction with moving the inner cap into the outer cap.

Abstract: A cap system for enclosing a metallic fastener assembly extending through a structure includes a first securement mechanism positioned about a periphery of a nut member of the metallic fastener assembly, wherein the first securement mechanism comprises threads which are interrupted as the threads extend about the periphery of the nut member and a cap member. The cap member includes a sidewall having an inner surface which defines a cavity dimensioned to receive the nut member and defines a second securement mechanism complementary configured to engage the first securement mechanism positioned about the periphery of the nut member and an end of the sidewall of the cap member defines an opening which provides the nut member to have access into the cavity.

Abstract: A cap system for enclosing a metallic bolt fastener extending through a structure which includes a first securement mechanism positioned about a periphery of a bolt head of the metallic bolt fastener. The cap system further includes a cap member which includes a sidewall having an inner surface which defines a cavity dimensioned to receive the bolt head and defines a second securement mechanism complementary configured to engage the first securement mechanism positioned about the periphery of the bolt head. The cap system further includes an end of the sidewall of the cap member which defines an opening which provides the bolt head access into the cavity.

Abstract: Disclosed herein are methods and compositions for preparing a surface comprising thermoplastic or thermoset material to receive a polysulfide or polythioether sealant or coating, the method comprising applying to the surface an activating composition consisting of a tetraalkoxide of a Group 4 metal, a complex of an alkoxide of a Group 4 metal, or a combination thereof.