Tungsten fiber-reinforced copper composites form high strength electrical conductors

Tungsten fiber-reinforced copper composites have tensile strength, yield strength, and modulus of elasticity proportional to fiber content. The composites form high strength electrical conductors

Effect of fiber diameter and matrix alloys on impact-resistant boron/aluminum composites

Efforts to improve the impact resistance of B/Al are reviewed and analyzed. Nonstandard thin-sheet charpy and Izod impact tests and standard full-size Charpy impact tests were conducted on composites containing unidirectional 0.10mm, 0.14mm, and 0.20mm diameter boron fibers in 1100, 2024, 5052, and 6061 Al matrices. Impact failure modes of B/Al are proposed in an attempt to describe the mechanisms involved and to provide insight for maximizing impact resistance. The impact strength of B/Al was significantly increased by proper selection of materials and processing. The use of a ductile matrix and large diameter boron fibers gave the highest impact strengths. This combination resulted in improved energy absorption through matrix shear deformation and multiple fiber breakage

Improved impact-resistant boron-aluminum composites for use as turbine engine fan blades

Efforts to improve the impact resistance of B/Al are reviewed and analyzed. Thin sheet Charpy and Izod impact tests and standard full size Charpy impact tests were conducted on unidirectional and angleply composites containing 4, 5.6 and 8 mil boron in 1100, 2024, 5052 and 6061 Al matrices. Impact failure modes of B/Al are proposed in an attempt to describe the mechanisms involved and to provide insight for maximizing impact resistance. The impact strength of B/Al was significantly increased by proper selection of materials and processing. The use of more ductile matrices (1100 Al) and larger diameter (8 mil) boron fibers gave the highest impact strengths by allowing matrix shear deformation and multiple fiber breakage

Effect of angleplying and matrix enhancement on impact-resistant boron/aluminum composites

Efforts to improve the impact resistance of B/Al are reviewed and analyzed. Tensile and dynamic modulus tests, thin sheet Charpy and Izod impact tests, and standard full size Charpy impact tests were conducted on 0.20 mm (8 mil) diameter-B/1100 Al matrix composites. Angleplies ranged from unidirectional to + or - 30 deg. The best compromise between reduced longitudinal properties and increased transverse properties was obtained with + or - 15 deg angleply. The pendulum impact strengths of improved B/Al were higher than that of notched titanium and appear to be enough to warrant consideration of B/Cl for application to fan blades in aircraft gas turbine engines

Evaluation of low-cost aluminum composites for aircraft engine structural applications

Panels of discontinuous SiC composites, with several aluminum matrices, were fabricated and evaluated. Modulus, yield strength and tensile strength results indicated that the properties of composites containing SiC whisker, nodule or particulate reinforcements were similar. The modulus of the composites was controlled by the volume percentage of the SiC reinforcement content, while the strength and ductility were controlled by both the reinforcement content and the matrix alloy. The feasibility of fabricating structural shapes by both wire performs and direct casting was demonstrated for Al2O3/Al composites. The feasibility of fabricating high performance composites into structural shapes by low pressure hot molding was demonstrated for B4C-coated B/Al composites

Advanced aircraft engine materials trends

Recent activities of the Lewis Research Center are reviewed which are directed toward developing materials for rotating hot section components for aircraft gas turbines. Turbine blade materials activities are directed at increasing metal temperatures approximately 100 C compared to current directionally solidified alloys by use of oxide dispersion strengthening or tungsten alloy wire reinforcement of nickel or iron base superalloys. The application of thermal barrier coatings offers a promise of increasing gas temperatures an additional 100 C with current cooling technology. For turbine disk alloys, activities are directed toward reducing the cost of turbine disks by 50 percent through near net shape fabrication of prealloyed powders as well as towards improved performance. In addition, advanced alloy concepts and fabrication methods for dual alloy disks are being studied as having potential for improving the life of future high performance disks and reducing the amount of strategic materials required in these components

Reinforced metallic composites Patent

High strength reinforced metallic composites for applications over wide temperature rang

La comunicazione della patologia fetale. Il punto di vista della donna, del medico e dell’équipe

La comunicazione della patologia fetale riveste una serie di significati con implicazioni psicologiche e sociali importanti che richiedono al medico capacità comunicativa, attitudine alla comprensione della paziente e delle dinamiche istituzionali. La donna: la patologia ostetrica è una crisi dentro la crisi. Nella patologia ostetrica le aspettative di vivere la nuova condizione di madre e di sentirsi più compiutamente famiglia vengono frustrate e tradite. In seguito alla diagnosi di patologia, alla perdita del bambino immaginario può seguire la perdita del bambino reale. Nel caso in cui la coppia decida di proseguire la gravidanza, il sentimento di lutto può prolungarsi per tutta la vita. Il medico: dal momento della prima diagnosi per la donna inizia l’elaborazione del lutto. Anche il medico che comunica la diagnosi vive questo momento con disagio. Inoltre, il medico sente il disagio dell’incertezza: l’incertezza può essere accolta e ascoltata. Raramente in questa situazione è possibile comunicare in modo efficace le informazioni necessarie. È importante comunicare gradualmente e dedicare un secondo incontro alle richieste di spiegazioni. L’équipe: è importante che gli operatori possano condividere questa esperienza all’interno dell’equipe. L’equipe che si occupa di diagnosi prenatale dovrebbe essere composta da persone che hanno scelto liberamente di occuparsi di questo aspetto della medicina. L’equipe diviene un contenitore per le emozioni estreme delle pazienti e degli operatori

Visualising transformative spaces for education: a focus on lecture halls, computer rooms and studios

One room, three learning spaces for creative education. This image-led investigation shows how a standard blank room can be effectively transformed into three different kinds of learning environments: a lecture hall, a computer room and a studio. Research has shown that effective design of teaching spaces is beneficial to the learning experience and contributes to creating a more engaging relationship between teachers and learners. On the other hand, few visual resources have been produced to support this in the UK. This article seeks to fill this gap. The design of these classrooms applies Basye’s idea of campfire to stimulate and support interaction between teachers and learners. In particular, these visuals show how technology can improve the students’ experience of the lecture hall, provide adequate lighting, personal space and drawing devices in the computer room, and finally how gathering in a circle may replicate the benefits of campfires in the studio