19,130 research outputs found

    A study to trial the use of inertial non-optical motion capture for ergonomic analysis of manufacturing work

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    It is going to be increasingly important for manufacturing system designers to incorporate human activity data and ergonomic analysis with other performance data in digital design modelling and system monitoring. However, traditional methods of capturing human activity data are not sufficiently accurate to meet the needs of digitised data analysis; qualitative data are subject to bias and imprecision, and optically derived data are hindered by occlusions caused by structures or other people in a working environment. Therefore, to meet contemporary needs for more accurate and objective data, inertial non-optical methods of measurement appear to offer a solution. This article describes a case study conducted within the aerospace manufacturing industry, where data on the human activities involved in aircraft wing system installations was first collected via traditional ethnographic methods and found to have limited accuracy and suitability for digital modelling, but similar human activity data subsequently collected using an automatic non-optical motion capture system in a more controlled environment showed better suitability. Results demonstrate the potential benefits of applying not only the inertial non-optical method in future digital modelling and performance monitoring but also the value of continuing to include qualitative analysis for richer interpretation of important explanatory factors

    Rheology and ultrasonic properties of Pt57.5Ni5.3Cu14.7P22.5 liquid

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    The equilibrium and nonequilibrium viscosity and isoconfigurational shear modulus of Pt57.5Ni5.3Cu14.7P22.5 supercooled liquid are evaluated using continuousā€“strain-rate compression experiments and ultrasonic measurements. By means of a thermodynamically-consistent cooperative shear model, variations in viscosity with both temperature and strain rate are uniquely correlated to the variations in isoconfigurational shear modulus, which leads to an accurate prediction of the liquid fragility and to a good description of the liquid strain-rate sensitivity

    TREATMENT OF HEMOPHILIA WITH HUMAN FACTORIX PRODUCED IN MAMIMARY TISSUE OF TRANSGENIC MAMMALS

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    Recombinant Factor IX characterized by a high percentage of active protein can be obtained in the milk of transgenic animals that incorporate chimeric DNA molecules according to the present invention. Transgenic animals of the present invention are produced by introducing into developing embryos DNA that encodes Factor IX, such that the foreign DNA is stably incorporated in the DNA of germ line cells of the mature animal. Particularly efficient expression was accomplished using a chimeric construct comprising a mammary gland specific promoter, Factor IX cDNA that lacked the complete or any portion of the 5\u27-untranslated and 3\u27-un-translated region, which is substituted with a 5- and 3\u27-end of the mouse whey acidic protein gene. In vitro cell cultures of cells explanted from the transgenic mammal of the invention and methods of producing Factor IX from such said culture and methods of treating hemophilia B are also described

    Thermal expansion of liquid Tiā€“6Alā€“4V measured by electrostatic levitation

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    The liquid density of Tiā€“6Alā€“4V was measured over a temperature range from 1661 to 1997 K that included undercooling by as much as 280 K. The sample was levitated in an electrostatic levitator and video imaging technique was used to capture the volume changes as a function of temperature. Over the temperature range the liquid density can be expressed by rholiq(T)=4123ā€“0.254 (Tā€“Tm) kg/m^3, where the melting temperature Tm is 1943 K. The corresponding volume expansion coefficient is alphaliq=6.05Ɨ10^ā€“5 K^ā€“1 near Tm

    Anelastic to Plastic Transition in Metallic Glass-Forming Liquids

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    The configurational properties associated with the transition from anelasticity to plasticity in a transiently deforming metallic glass-forming liquid are studied. The data reveal that the underlying transition kinetics for flow can be separated into reversible and irreversible configurational hopping across the liquid energy landscape, identified with beta and alpha relaxation processes, respectively. A critical stress characterizing the transition is recognized as an effective Eshelby ā€œbackstress,ā€ revealing a link between the apparent anelasticity and the ā€œconfinement stressā€ of the elastic matrix surrounding the plastic core of a shear transformation zone

    Utilization and Application of Business Computing Systems in Corporate Real Estate

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    This study reports on the utilization of business computing systems by corporate real estate executives. A survey was undertaken to examine four issues: types of property data collected, MIS report generation, hardware/software usage, and decision models and experts employed. NACORE members were surveyed and reported extensive usage of well-known business computing systems (e.g., transaction processing and management information systems), while newer systems (e.g., decision support and expert systems) are just beginning to be introduced into corporate real estate. Empirical analysis revealed differences among industries in the types of reports and property financial data that are maintained.

    Deformation of glass forming metallic liquids: Configurational changes and their relation to elastic softening

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    The change in the configurational enthalpy of metallic glass forming liquids induced by mechanical deformation and its effect on elastic softening is assessed. The acoustically measured shear modulus is found to decrease with increasing configurational enthalpy by a dependence similar to one obtained by softening via thermal annealing. This establishes that elastic softening is governed by a unique functional relationship between shear modulus and configurational enthalpy

    Frequency-dependent attenuation and elasticity in unconsolidated earth materials: effect of damping

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    We use the Discrete Element Method (DEM) to understand the underlying attenuation mechanism in granular media, with special applicability to the measurements of the so-called effective mass developed earlier. We consider that the particles interact via Hertz-Mindlin elastic contact forces and that the damping is describable as a force proportional to the velocity difference of contacting grains. We determine the behavior of the complex-valued normal mode frequencies using 1) DEM, 2) direct diagonalization of the relevant matrix, and 3) a numerical search for the zeros of the relevant determinant. All three methods are in strong agreement with each other. The real and the imaginary parts of each normal mode frequency characterize the elastic and the dissipative properties, respectively, of the granular medium. We demonstrate that, as the interparticle damping, Ī¾\xi, increases, the normal modes exhibit nearly circular trajectories in the complex frequency plane and that for a given value of Ī¾\xi they all lie on or near a circle of radius RR centered on the point āˆ’iR-iR in the complex plane, where Rāˆ1/Ī¾R\propto 1/\xi. We show that each normal mode becomes critically damped at a value of the damping parameter Ī¾ā‰ˆ1/Ļ‰n0\xi \approx 1/\omega_n^0, where Ļ‰n0\omega_n^0 is the (real-valued) frequency when there is no damping. The strong indication is that these conclusions carry over to the properties of real granular media whose dissipation is dominated by the relative motion of contacting grains. For example, compressional or shear waves in unconsolidated dry sediments can be expected to become overdamped beyond a critical frequency, depending upon the strength of the intergranular damping constant.Comment: 28 pages, 7 figure

    One Health in food safety and security education: Subject matter outline for a curricular framework.

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    Educating students in the range of subjects encompassing food safety and security as approached from a One Health perspective requires consideration of a variety of different disciplines and the interrelationships among disciplines. The Western Institute for Food Safety and Security developed a subject matter outline to accompany a previously published One Health in food safety and security curricular framework. The subject matter covered in this outline encompasses a variety of topics and disciplines related to food safety and security including effects of food production on the environment. This subject matter outline should help guide curriculum development and education in One Health in food safety and security and provides useful information for educators, researchers, students, and public policy-makers facing the inherent challenges of maintaining and/or developing safe and secure food supplies without destroying Earth's natural resources
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