584 research outputs found

    Connection system

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    A mechanical connection system comprises a first body defining a receptable and a second body defining a pin matingly receivable in the receptacle by relative movement in a first directional mode. A primary latch is engagable between the two bodies to retain the pin in the receptacle. The primary latch is reciprocable in a second directional mode transverse to the first directional mode. A lock member carried by one of the bodies is operatively associated with the primary latch and movable, transverse to the second directional mode, between a locking position maintaining engagement of the primary latch and a releasing position permitting release of the primary latch. The lock includes an operator portion engagable to move the lock member from its locking position to its releasing position. The operator is located internally of the first body. An actuator is selectivity insertable into and disengagable from the first body. The actuator is movable relative to the first body when it is inserted for engagement with and operation of the operator

    Menthol sensory qualities and smoking topography: a review of tobacco industry documents.

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    ObjectiveTo determine what the tobacco industry knew about the potential effects of menthol on smoking topography-how a person smokes a cigarette.MethodsA snowball strategy was used to systematically search the Legacy Tobacco Documents Library (http://legacy.library.ucsf.edu) between 1 June 2010 and 9 August 2010. We qualitatively analysed a final collection of 252 documents related to menthol and smoking topography.ResultsThe tobacco industry knew that menthol has cooling, anaesthetic and analgesic properties that moderate the harshness and irritation of tobacco. Owing to its physiological effects, menthol contributes to the sensory qualities of the smoke and affects smoking topography and cigarette preference.ConclusionOur review of industry studies suggests that the amount of menthol in a cigarette is associated with how the cigarette is smoked and how satisfying it is to the smoker. If menthol in cigarettes was banned, as the US Food and Drug Administration (FDA) is currently considering, new/experimental smokers might choose not to smoke rather than experience the harshness of tobacco smoke and the irritating qualities of nicotine. Similarly, established menthol smokers might choose to quit if faced with an unpleasant smoking alternative

    Management and Decision Making Practices of 38 Young South Dakota Families

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    The main objectives of the study were to learn about the management and decision-making practices of young rural and urban South Dakota families. Data were collected from 38 families randomly chosen during the spring of 1968 from 10 southeastern South Dakota counties. They were Aurora, Bon Homme, Brule, Clay, Davison, Lincoln, McCook, Minnehaha, Turner, and Yankton counties. By use of a table of random numbers the families were selected from the personal property tax listings in each county. In addition the school assessor\u27s list was checked to see if any children were present in the household. To qualify for the study the wife had to be under 35 years of age and have one or more children. After selection each family was sent a letter indicating that they had been randomly selected and that an interviewer would contact them soon. Data were collected by personal interview by selected home economics extension agents from the 10 counties, state home economics extension personnel, and the writer. Time per interview averaged about two hours. Each family was asked questions about values and goals, decision making, financial security, management of money, allocation of income, homemaking skills, buymanship, as well as leisure time activities, community participation, and demographic information. A second call was made to some households or the homemaker mailed eight pages of the questionnaire to the interviewer

    Laserlight visual cueing device for freezing of gait in Parkinson's disease: a case study of the biomechanics involved

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    AbstractBackground: Freezing of gait (FOG) is a serious gait disorder affecting up to two-thirds of people with Parkinson's disease (PD). Cueing has been explored as a method of generating motor execution using visual transverse lines on the floor. However, the impact of a laser light visual cue remains unclear. Objective: To determine the biomechanical effect of a laser cane on FOG in a participant with PD compared to a healthy age- and gender-matched control. Methods: The participant with PD and healthy control were given a task of initiating gait from standing. Electromyography (EMG) data were collected from the tibialis anterior (TA) and the medial gastrocnemius (GS) muscles using an 8-channel system. A 10-camera system (Qualisys) recorded movement in 6 degrees of freedom and a calibrated anatomical system technique was used to construct a full body model. Center of mass (COM) and center of pressure (COP) were the main outcome measures. Results: The uncued condition showed that separation of COM and COP took longer and was of smaller magnitude than the cued condition. EMG activity revealed prolonged activation of GS, with little to no TA activity. The cued condition showed earlier COM and COP separation. There was reduced fluctuation in GS, with abnormal, early bursts of TA activity. Step length improved in the cued condition compared to the uncued condition. Conclusion: Laserlight visual cueing improved step length beyond a non-cued condition for this patient indicating improved posture and muscle control

    Structural and Physical Properties of CaFe4As3 Single Crystals

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    We report the synthesis, and structural and physical properties of CaFe4As3 single crystals. Needle-like single crystals of CaFe4As3 were grown out of Sn flux and the compound adopts an orthorhombic structure as determined by X-ray diffraction measurements. Electrical, magnetic, and thermal properties indicate that the system undergoes two successive phase transitions occurring at TN1 ~ 90 K and TN2 ~ 26 K. At TN1, electrical resistivities (\rho(b) and \rho(ac)) are enhanced while magnetic susceptibilities (\chi(b) and \chi(ac)) are reduced in both directions parallel and perpendicular to the b-axis, consistent with the scenario of antiferromagnetic spin-density-wave formation. At TN2, specific heat reveals a slope change, and \chi(ac) decreases sharply but \chi(b) has a clear jump before it decreases again with decreasing temperature. Remarkably, both \rho(b) and \rho(ac) decrease sharply with thermal hysteresis, indicating the first-order nature of the phase transition at TN2. At low temperatures, \rho(b) and \rho(ac) can be described by {\rho} = {\rho}0 + AT^\alpha ({\rho}0, A, and {\alpha} are constants). Interestingly, these constants vary with applied magnetic field. The ground state of CaFe4As3 is discussed.Comment: 15 pages, 8 figures, Submitted to Physical Review

    Surface and Bulk Structural Properties of Single Crystalline Sr3Ru2O7

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    We report temperature and thermal-cycling dependence of surface and bulk structures of double-layered perovskite Sr3Ru2O7 single crystals. The surface and bulk structures were investigated using low-energy electron diffraction (LEED) and single-crystal X-ray diffraction (XRD) techniques, respectively. Single-crystal XRD data is in good agreement with previous reports for the bulk structure with RuO6 octahedral rotation, which increases with decreasing temperature (~ 6.7(6)degrees at 300 K and ~ 8.1(2) degrees at 90 K). LEED results reveal that the octahedra at the surface are much more distorted with a higher rotation angle (~ 12 degrees between 300 and 80 K) and a slight tilt ((4.5\pm2.5) degrees at 300 K and (2.5\pm1.7) degrees at 80 K). While XRD data confirms temperature dependence of the unit cell height/width ratio (i.e. lattice parameter c divided by the average of parameters a and b) found in a prior neutron powder diffraction investigation, both bulk and surface structures display little change with thermal cycles between 300 and 80 K.Comment: 25 pages, 5 figures, 5 tables, to appear in Physical Review

    Design Concept for a Reusable/Propellantless MXER Tether Space Transportation System

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    The Momentum Exchange/Electrodynamic Reboost (MXER) tether facility is a transformational concept that significantly reduces the fuel requirements (and associated costs) in transferring payloads above low earth orbit (LEO). Facility reboost is accomplished without propellant by driving current against a voltage created by a conducting tether's interaction with the Earth's magnetic field (electrodynamic reboost). This system can be used for transferring a variety of payloads (scientific, cargo, and human space vehicles) to multiple destinations including geosynchronous transfer orbit, the Moon or Mars. MXER technology advancement requires development in two key areas: survivable, high tensile strength non-conducting tethers and reliable, lightweight payload catch/release mechanisms. Fundamental requirements associated with the MXER non-conducting strength tether and catch mechanism designs will be presented. Key requirements for the tether design include high specific-strength (tensile strength/material density), material survivability to the space environment (atomic oxygen and ultraviolet radiation), and structural survivability to micrometeoroid/orbital debris (MM/OD) impacts. The driving mechanism key,gequirements include low mass-to-capture-volume ratio, positional and velocity error tolerance, and operational reliability. Preliminary tether and catch mechanism design criteria are presented, which have been used as guidelines to "screen" and down-select initial concepts. Candidate tether materials and protective coatings are summarized along with their performance in simulated space environments (e.g., oxygen plasma, thermal cycling). A candidate catch mechanism design concept is presented along with examples of demonstration hardware

    Bayesian Estimation of the Size of a Street-Dwelling Homeless Population

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    A novel Bayesian technique is proposed to calculate 95% interval estimates for the size of the homeless population in the city of Edmonton using plant-capture data from Toronto, Canada. The probabilities of capture in Edmonton and Toronto are modeled as exchangeable in a hierarchical Bayesian model, and Markov chain Monte Carlo is used to sample from the posterior distribution. Guidelines are recommended for applying the method to assess the accuracy of homeless counts in other cities
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