Grapho-analytical studies of deformation in deformed thin-walled contours

Increasing the levels of operational reliability of technical means of modern production involves, in particular, the optimization of the deformation parameters of individual components of these tools. The main deformation-operational feature of such structures as elastic shells of the pneumatic periphery of mobile vehicles, and individual links of long-link cargo chains is a stochastic change of their shape in contact with the deformed environment. The basis for the optimization of the operational reliability of deformed thin-walled circuits of such structures under power load is to determine the ratios of their geometric parameters, in which the process of deformation under load does not transform their initial shape from “folded” (out-of-bounds) state to “foldless” state toroidal surfaces, which should be described using the Cassini family of ovals. Based on the established regularities of changing the configuration of the meridian of soft elastic shell and flat closed structures, which are deformed by external loads, three main conditions of using model typical contours of Cassini ovals as graph-analytical models of elastic shells of pneumatic mobile periphery chains. These conditions of graph-analytical modelling include: closedness and continuity of the curvature of the toroidal surface; generalization of the initial shape of the surfaces of toroidal contours; reduction of variable geometric shapes of contours to a single generalized equation. The results of the given grapho-analytical researches allow to define design structural and geometrical parameters of tires of engines of mobile means and separate links of cargo chains with the increased operational indicators of reliability of their work.

3D Pen Tactile Pictures Generated by Individuals with Visual Impairments

Introduction: Individuals with visual impairments acquire information about objects through touch and by use of auxiliary tactile pictures. The current study introduced a new three-dimensional (3D) printing pen technology as a research tool to allow individuals with visual impairments to convert tactile experiences to convex tactile pictures. Methods: Participants with visual impairments used a 3D pen to draw pictures of daily necessities. The actions and time related to the entire drawing activity were recorded on video. Results: We noted three behaviors during the use of 3D pen: drawing, touching the trace lines, and finding location points. The object-depiction angle, component-completeness description, and drawing-line presentation differed between subjects with congenital and those with acquired blindness. Discussion: Individuals with congenital blindness depicted objects mainly from an operational angle, and those with acquired blindness from the angle of the object when laid flat. When the components of an object were relatively complex, the subjects with congenital blindness only drew local features in contact with their bodies and with continuous line segments, and those with acquired blindness used discontinuous line segments. Participants were satisfied that the 3D printing pen could touch the drawing path in time and that they could use the “piling” feature to create positioning marks or planar expressions. Implications for practitioners: Students can be instructed to use 3D pens to draw (lines, planes, and objects) to enhance the communication between teachers and students and improve teaching efficiency. Regarding the design of tactile pictures, the parts that come in contact with the body during object use can be considered the reference features of the pictures. For large pictures, attention should be paid to the size ratio between the outline and components. For small pictures, one should consider how the operational feature details should be shown at approximately the original size.

Attention to breath sensations does not engage endogenous opioids to reduce pain

The endogenous opioidergic system is critically involved in the cognitive modulation of pain. Slow-breathing based techniques are widely utilized non-pharmacological approaches to reduce pain, although the active mechanisms of actions supporting these practices are poorly characterized. Growing evidence suggest that mindfulness-meditation, a slow-breathing technique practiced by non-reactively attending to breathing sensations, engages multiple unique neural mechanisms that bypass opioidergically mediated descending pathways to reduce pain. Yet, it is unknown if endogenous opioids contribute to pain-reductions produced by slow-breathing. The present double-blind, placebo-controlled crossover study examined behavioral pain responses during mindfulness-meditation (n=19), sham-mindfulness meditation (n=20), and slow-paced breathing (n=20) in response to noxious heat (49°C) and intravenous administration (0.15 mg/kg bolus + 0.1 mg/kg/h maintenance infusion) of the opioid antagonist, naloxone and placebo-saline. Mindfulness significantly reduced pain unpleasantness ratings across both infusion sessions when compared to rest, but not pain intensity. Slow-paced breathing significantly lower pain intensity and unpleasantness ratings during naloxone but not saline. Pain reductions produced by mindfulness-meditation and slow-paced breathing were insensitive to naloxone when compared to saline infusion. In contrast, sham-mindfulness meditation produced pain unpleasantness reductions during saline infusion but this effect was reversed by opioidergic antagonism. Sham-mindfulness did not lower pain intensity ratings. Self-reported “focusing on the breath” was identified as the operational feature particularly unique to the mindfulness-meditation and slow paced-breathing, but not sham-mindfulness meditation. Across all individuals, attending to the breath was associated with naloxone insensitive pain-relief. These findings provide evidence that slow-breathing combined with attention to breath reduces pain independent of endogenous opioids.

Research on an Online Monitoring and Diagnosis System of High-Voltage Circuit Breaker

The principle of an online monitoring and diagnosis system suitable for various kinds of High-voltage Circuit Breakers (HVCB) is presented in the paper. The system consists of distributed data acquisition devices, a communication system based on field bus, and a host based on B/S structure. The research presents the methods to select the main monitoring signals of high-voltage circuit breakers, to acquire data, and to calculate operational feature values, as well as realizes high-speed process to monitoring signals, valid online monitor to high-voltage circuit breakers, and fault diagnosis.

Simple Models for Airport Delays During Transition to a Trajectory-Based Air Traffic System

It is now widely recognised that a paradigm shift in air traffic control concepts is needed. This requires state-of-the-art innovative technologies, making much better use of the information in the air traffic management (ATM) system. These paradigm shifts go under the names of NextGen in the USA and SESAR in Europe, which inter alia will make dramatic changes to the nature of airport operations. A vital part of moving from an existing system to a new paradigm is the operational implications of the transition process. There would be business incentives for early aircraft fitment, it is generally safer to introduce new technologies gradually, and researchers are already proposing potential transition steps to the new system. Simple queuing theory models are used to establish rough quantitative estimates of the impact of the transition to a more efficient time-based – four-dimensional (4D) – navigational and ATM system. Such models are approximate, but they do offer insight into the broad implications of system change and its significant features. 4D-equipped aircraft in essence have a contract with the airport runway – they would be required to turn up at a very precise time – and, in return, they would get priority over any other aircraft waiting for use of the runway. The main operational feature examined here is the queuing delays affecting non-4D-equipped arrivals. These get a reasonable service if the proportion of 4D-equipped aircraft is low, but this can deteriorate markedly for high proportions, and be economically unviable. Preventative measures would be to limit the additional growth of 4D-equipped flights and/or to modify their contracts to provide sufficient space for the non-4D-equipped flights to operate without excessive delays. There is a potential for non-Poisson models, for which there is little in the literature, and for more complex models, e.g. grouping a succession of 4D-equipped aircraft as a batch.

Forensic Engineering Analysis Of The Four-Way-Stop Intersection Illusion

Right-Angle Crashes At Two-Way-Stop-Controlled Intersections Are Sometimes Caused By The Stopped Driver Entering The Conflict Area Under The Mistaken Impression That The Intersection Has Four-Way-Stop Control. The Cause Of The Illusion Is Often A Device Installed By The Engineer In An Attempt To Improve Safety, Such As A Flashing Intersection Control Beacon, Or Is A Normal Operational Feature Such As Curb Parking. Nine Such Cues, And Suggested Countermeasures, Are Explained Herein. It Is The Design Driver, Rather Than The Average One, Who Errs In This Way. This Is A Human-Factors Problem That Engineers And Psychologists Should Tackle Jointly.

DEVELOPMENT AND TESTS OF AN AIR-JET OIL BOOM1

ABSTRACT This paper describes the development of the Air-Jet Boom—a novel boom which has the capability to divert oil slicks under wave and current conditions that normally preclude the deployment of conventional booms. Tests at the EPA's Oil and Hazardous Materials Simulated Environmental Test Tank (OHMSETT) facility have demonstrated that this boom can, for example, successfully divert oil slicks at 3 knots with 85 percent efficiency when at 30° to the flow. Moreover, with the addition of steep, 4-foot waves, the boom's performance is virtually unchanged. 1 The key operational feature is a continuous, horizontally-oriented air jet ejected from along the boom near the water surface. The flow interaction and the ensuing momentum transfer from the air jet to the water surface (by viscous and turbulent shear stress) induces a strong local surface current just ahead of the boom. When the boom is deployed at an angle to the flow (diversionary mode), the induced current causes the oncoming oil slick to be deflected and transported across the water surf ace, apart from the clean underlying flow. Overall, each boom module is about 33 feet long and 2 feet in diameter. Major components include two inflatable sections (ducts) supporting the continuous air-jet nozzle and a center support-float/jet-pump arrangement to supply the high volume, low-pressure (23,000 SCFM at 3 inches of water) air flow required for operation. Some unique features of the structural design are low draft (one inch) and excellent compliance to waves. Furthermore, the sections are lightweight and highly compactible for storage.