1,580 research outputs found

    An Investigation of the Fracture of Butt Joints in Parallel-Laminated Veneer

    Get PDF
    A finite-element analysis and experimental testing program was conducted to investigate the fracture mechanics aspects of butt joints in parallel-laminated veneer (PLV). The effects of the number of plies, ply thickness, and joint spacing were investigated. It was found that the isotropic and orthotropic solutions for edge-cracked specimens were very close. Also, the increase in the stress-intensity factor for the exterior butt joint was of the order of only 4% for a joint separation spacing of four ply-thicknesses. In general, it was found that Mode I fracture toughness increased with decreasing veneer thickness and that the fracture toughness of exterior butt-jointed specimens varied with veneer thickness and number of plies. Results of the butt-joint interaction tests indicate a much higher degree of joint interaction than predicted by the finite-element analysis

    Potawatomi Indians of the West :

    Get PDF

    The Rocketdyne Multifunction Tester. Part 1: Test Method

    Get PDF
    The Rocketdyne Multifunction Tester is a general purpose test apparatus which utilizes axial and radial magnetic bearings as shaft excitation devices. The tester is modular in design so that different seal and bearing packages can be tested on the same test stand. The tester will be used for rotordynamic coefficient extraction, as well as life and fluid/material compatibility evaluations. Use of a magnetic bearing as a shaft excitation device opens up many possibilities for shaft excitation and rotordynamic coefficient extraction. In addition to describing the basic apparatus, some of the excitation and extraction methods are described. Some of the excitation methods to be discussed include random, aperiodic, harmonic, impulse and chirp

    A Wistful Farewell to Pink Bugg & Queen Caroline

    Get PDF

    Load Duration and Probability Based Design of Wood Structural Members

    Get PDF
    Methods are presented for calculating limit state probabilities of engineered wood structural members, considering load duration effects due to stochastic dead and snow load. These methods are used to conduct reliability studies of existing wood design criteria. When realistic load processes are considered, it is found that the importance of load duration and gradual damage accumulation has been somewhat overstated. One possible probability-based design method that should be useful in future code development work also is presented

    Tower tank valve flushing system for dairy facitlites

    Get PDF
    Flushing characteristics of a tower tank valve flushing system with a 12-inch-diameter manual valve were determined. Data were obtained using the outside cow alleys in a fourrow freestall barn. The alleys were 12 ft wide and 420 ft long with a 2% slope. The average flow rate exceeded 8,000 gallons per minute (gpm) when the average head was above 30 ft and the manual valve opened 80 degrees. Opening the valve to 90 degrees increased the flow rate to over 9,700 gpm. The velocity of the flushing wave was 8.5 fpm with a flow depth of 3.5 in. The estimated wave duration or alley contact time was 14.6 sec with a 25-40 sec release time from the flush tank. The flow rate ranged from 5,300 gpm to 7,200 gpm when the average head was between 16 and 28 ft.; Dairy Day, 1998, Kansas State University, Manhattan, KS, 1998

    The functional connectivity between the nucleus accumbens and the ventromedial prefrontal cortex as an endophenotype for bipolar disorder

    Get PDF
    Background Alterations in functional connectivity between the nucleus accumbens (NAcc) and frontal cortices have been previously associated with the presence of psychiatric syndromes, among them bipolar disorder. Whether these alterations are a consequence or a risk factor for mental disorders remains unresolved. Methods This study included 35 bipolar participants, 30 of their resilient siblings, and 23 healthy controls to probe functional connectivity at rest between NAcc and the rest of the brain in a cross-sectional design. BOLD time series at rest from NAcc were used as seed-region in a woxel-wise correlational analysis. The strength of the correlations found were compared across groups after Fisher’s Z transformation. Results Our results showed increased functional connectivity between NAcc and a ventromedial prefrontal cortex (vmPFC) - comprising mainly the subgenual anterior cingulate - in patients compared to controls. Participants at increased genetic risk but yet resilient – i.e. unaffected siblings - showed functional connectivity values midway between the former two groups. Conclusions Our results are indicative of the potential for the connectivity between NAcc and the vmPFC to represent an endophenotype for bipolar disorder

    The Potential of Positive Leadership for School Improvement

    Get PDF
    In this paper, we undertake four formative assignments: (1) We introduce the idea of positive school leadership (PSL) based largely on theory and research conducted outside the educational sector and introduce four orientations that anchor PSL; (2) we develop ideas about how asset-grounded concepts of leadership can be incorporated into schooling; (3) we examine how concepts underlying PSL may affect schools, classrooms, teachers, and students; and (4) using narrative research and grounded theory we introduce an overview of empirical evidence linking PSL and valued outcomes. We conclude by discussing the significance of PSL for organizational theory and leadership preparation and professional development
    • …
    corecore