3,188 research outputs found

    Rapid induction bonding of composites, plastics, and metals

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    The Toroid Bonding Gun is and induction heating device. It is a self contained, portable, low powered induction welding system developed for bonding or joining plastic, ceramic, or metallic parts. Structures can be bonded in a factory or in a the field. This type of equipment allows for applying heat directly to the bond lines and/or to the adhesives without heating the entire structure, supports, and fixtures of a bonding assembly. The induction heating gun originally developed for use in the fabrication of space Gangs of bonders are now used to rapidly join composite sheet and structural components. Other NASA-developed applications of this bonding technique include the joining of thermoplastic composites, thermosetting composites, metals, and combinations of these materials

    Ceramic susceptor for induction bonding of metals, ceramics, and plastics

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    A thin (.005) flexible ceramic susceptor (carbon) was discovered. It was developed to join ceramics, plastics, metals, and combinations of these materials using a unique induction heating process. Bonding times for laboratory specimens comparing state of the art technology to induction bonding were cut by a factor of 10 to 100 times. This novel type of carbon susceptor allows for applying heat directly and only to the bondline without heating the entire structure, supports, and fixtures of a bonding assembly. The ceramic (carbon film) susceptor produces molten adhesive or matrix material at the bond interface. This molten material flows through the perforated susceptor producing a fusion between the two parts to be joined, which in many instances has proven to be stronger than the parent material. Bonding can be accomplished in 2 minutes on areas submitted to the inductive heating. Because a carbon susceptor is used in bonding carbon fiber reinforced plastics and ceramics, there is no radar signature or return making it an ideal process for joining advanced aerospace composite structures

    Home-Based Parent-Child Therapy in Low-Income African American, Caucasian, and Latino Families: A Comparative Examination of Treatment Outcomes

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    This study examined parent and child treatment outcomes for a home-based Parent-Child Therapy (PCT) program for 66 children from families living in poverty. African American, Caucasian, and Latino families were examined to determine if an evidence-based program would produce similar results across different ethnic groups. The results showed that caregivers across the three ethnic groups reported improved child challenging behavior, increased positive parent-child interactions, improved parental expectations, higher levels of nurturing, and less reliance on verbal and corporal punishment as a form of discipline. Practical implications for these results are discussed

    Evaluation of a University-Community Partnership to Provide Home-Based, Mental Health Services for Children from Families Living in Poverty

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    A university-community partnership is described that resulted in the development of community-based mental health services for young children from families living in poverty. The purpose of this pilot project was to implement an evidence-based treatment program in the homes of an at-risk population of children with significant emotional and behavior problems that were further complicated by developmental delays. Outcomes for 237 children who participated in the clinic’s treatment program over a 2 year period are presented. Comparisons are included between treatment completers and non-completers and the issues of subject attrition, potential subject selection bias, and the generalizability of the results are addressed. The need for more professionals who are trained to address mental health issues in very young children who live in very challenging conditions are discussed

    Oppositional Defiant Disorder and Aggression in a Young Man with Mental Retardation: Long-Term Treatment in a Community-Based Setting

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    A longitudinal, intensive treatment program is described that was implemented over an 8-year period in a community-based setting for a young man with mental retardation and oppositional defiant disorder with severe physical aggression. The development of this disorder and its systematic treatment are described, with new components added based on improvement in the individual’s behavior. The individual made steady progress and has maintained good behavioral stability for the final three years of the treatment program. This paper highlights the inherent difficulties of applying empirically validated treatment strategies in community-based settings

    Method of Attaching Strain Gauges to Various Materials

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    A method is provided to bond strain gauges to various materials. First, a tape with an adhesive backing is placed across the inside of the fixture frame. The strain gauge is flatly placed against the adhesive backing and coated with a thin, uniform layer of adhesive. The tape is then removed from the fixture frame and placed, strain gauge side down, on the material to be tested. If the material is a high reluctance material, the induction heating source is placed on the tape. If the material is a low reluctance material, a plate with a ferric side and a rubber side is placed, ferric side down, onto the tape. The induction heating source is then placed upon the rubber side. If the material is an insulator material, a ferric plate is placed on the tape. The induction heating source is then placed on the ferric plate. The inductive heating source then generates frequenty from 60 to 70 kilocycles to inductively heat either low reluctance material, ferric side, of ferric plate and provides incidental pressure of approximately five pounds per square inch to the tape for two minutes, thoroughly curing the adhesive. The induction heating source, and, if necessary, the plate or ferric plate, are then removed from the tape after one minute. The tape is then removed from the bonded strain gauge

    System and Method for Monitoring Piezoelectric Material Performance

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    A system and method are provided for monitoring performance capacity of a piezoelectric material that may form part of an actuator or sensor device. A switch is used to selectively electrically couple an inductor to the piezoelectric material to form an inductor-capacitor circuit. Resonance is induced in the inductor-capacitor circuit when the switch is operated to create the circuit. The resonance of the inductor-capacitor circuit is monitored with the frequency of the resonance being indicative of performance capacity of the device's piezoelectric material

    Electro-Active Transducer Using Radial Electric Field To Produce/Motion Sense Out-Of-Plane Transducer

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    An electro-active transducer includes a ferroelectric material sandwiched by first and second electrode patterns. When the device is used as an actuator, the first and second electrode patterns are configured to introduce an electric field into the ferroelectric material when voltage is applied to the electrode patterns. When the device is used as a sensor. the first and second electrode patterns are configured to introduce an electric field into the ferroelectric material when the ferroelectric material experiences deflection in a direction substantially perpendicular thereto. In each case, the electrode patterns are designed to cause the electric field to: i) originate at a region of the ferroelectric material between the first and second electrode patterns. and ii) extend radially outward from the region of the ferroelectric material (at which the electric field originates) and substantially parallel to the ferroelectric material s plane

    Electro-active device using radial electric field piezo-diaphragm for sonic applications

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    An electro-active transducer for sonic applications includes a ferroelectric material sandwiched by first and second electrode patterns to form a piezo-diaphragm coupled to a mounting frame. When the device is used as a sonic actuator, the first and second electrode patterns are configured to introduce an electric field into the ferroelectric material when voltage is applied to the electrode patterns. When the device is used as a sonic sensor, the first and second electrode patterns are configured to introduce an electric field into the ferroelectric material when the ferroelectric material experiences deflection in a direction substantially perpendicular thereto. In each case, the electrode patterns are designed to cause the electric field to: i) originate at a region of the ferroelectric material between the first and second electrode patterns, and ii) extend radially outward from the region of the ferroelectric material (at which the electric field originates) and substantially parallel to the plane of the ferroelectric material. The mounting frame perimetrically surrounds the peizo-diaphragm and enables attachment of the piezo-diaphragm to a housing

    Nitrogen and Potassium Interact to Shape a Yield Response Surface

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    In a field experiment with banana, fertilizer variables were applied systematically in strips across the blocks so that N increased gradually from none to large quantities in one direction, while K increased gradually perpendicular to the N fertilizer. An aerial view of the blocks and a plot of banana yields as influenced by the variables illustrate the interaction of the nutrients applied
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