SENSOR ARRAY ABLE TO DETECT AND RECOGNISE CHEMICAL WARFARE AGENTS

In this paper we studied a device based on array of six different sensors with surface acoustic wave for detections and recognition of three chemical warfare agents (chloropicrin, soman and lewisite). The sensors are “delay line” type with a center frequency of 69.4 MHz. It presents an original algorithm to identify the nature and concentration of gas from a finite range of possible gases. Numerical program developed to implement this algorithm, provides to operators all the particulars of gas and an indicator of credibility of the results provided as a measure of the degree of disturbance of the signals received from sensors.SAW, chemical warfare agent, array of sensors, algorithm

Approximation for Scheduling on Parallel Machines with Fixed Jobs or Unavailability Periods

We survey results that address the problem of non-preemptive scheduling on parallel machines with fixed jobs or unavailability periods with the purpose of minimizing the maximum completion time. We consider both identical and uniform processors, and also address the special case of scheduling on nonsimultaneous parallel machines, which may start processing at different times. The discussed results include polynomial-time approximation algorithms that achieve the best possible worst-case approximation bound of 1.5 in the class of polynomial algorithms unless P = NP for scheduling on identical processors with at most one fixed job on each machine and on uniform machines with at most one fixed job on each machine. The presented heuristics have similarities with the LPT algorithm or the MULTIFIT algorithm and they are fast and easy to implement. For scheduling on nonsimultaneous machines, experiments suggest that they would perform well in practice. We also include references to the relevant work in this area that contains more complex algorithms. We then discuss the main methods of argument used in the approximation bound proofs for the simple heuristics, and comment upon current challenges in this area by describing aspects of related practical problems from the automotive industry

Reorienting to Expectations of Change

This paper explains implicit and explicit theoretical assumptions of change and an emerging reorientation to expectations of change by using activity and meaning making theory to uncover a more expanded, integrated understanding of our expectations of change. The purpose of this reorganization is to better navigate social interactions as practitioner theorists

Stochastic Properties of Static Friction

The onset of frictional motion is mediated by rupture-like slip fronts, which nucleate locally and propagate eventually along the entire interface causing global sliding. The static friction coefficient is a macroscopic measure of the applied force at this particular instant when the frictional interface loses stability. However, experimental studies are known to present important scatter in the measurement of static friction; the origin of which remains unexplained. Here, we study the nucleation of local slip at interfaces with slip-weakening friction of random strength and analyze the resulting variability in the measured global strength. Using numerical simulations that solve the elastodynamic equations, we observe that multiple slip patches nucleate simultaneously, many of which are stable and grow only slowly, but one reaches a critical length and starts propagating dynamically. We show that a theoretical criterion based on a static equilibrium solution predicts quantitatively well the onset of frictional sliding. We develop a Monte-Carlo model by adapting the theoretical criterion and pre-computing modal convolution terms, which enables us to run efficiently a large number of samples and to study variability in global strength distribution caused by the stochastic properties of local frictional strength. The results demonstrate that an increasing spatial correlation length on the interface, representing geometric imperfections and roughness, causes lower global static friction. Conversely, smaller correlation length increases the macroscopic strength while its variability decreases. We further show that randomness in local friction properties is insufficient for the existence of systematic precursory slip events. Random or systematic non-uniformity in the driving force, such as potential energy or stress drop, is required for arrested slip fronts. Our model and observations..

Study on Optical Fiber Insertion in Underground Telecommunication Networks Using Hydraulic Similarity

AbstractThe European regulations require a new approach of cities facilities networks, including the communication ones. In this respect, the communication providers generalize the underground networks, following the streets trails. The transmission support consists in a network of tubes, protecting a number of micro-tubes/microducts, which protect the real transmission facilitators made by optical fibers. Presently, the producers of this type of devices promote special norms of information on characteristics and installation of the product, but there are not reliable accepted standardized methods for optical fibers insertion in pre-installed micro-tubes/microducts and for the devices forces computation, necessary for underground communication networks. The micro-tubes are already installed in the protection cables and together are buried in the ground on different routes. It appears the necessity to introduce the fibers in the micro-tubes in this situation. Generally, it is a significant difference between the practical reality and the producers norms and indicators. In order to explain this situation, and considering the optical fibers dimensions, and the necessity to insert the fibers using specific lubricants, the paper propose a similarity model of the optical fibers insertion in the micro-tubes with the hydraulic model of laminar incompressible fluids flow in parallel or concentric micro- layers. In this phase, there are presented the results of experimental measurements and tests on in situ networks, composed by different types of materials and lubricants, as support for the hydraulic similitude

The Positive and Negative Experiences of 342 Antidepressant Users

Most efficacy and safety studies about medications adopt a quantitative approach, testing specific hypotheses with restricted samples. This online survey provides additional insights by directly asking people open questions. Thematic analysis was used to explore the responses of 342 antidepressant users to “Is there anything else you would like to tell us about your experience of taking medication”. 59 (17.3%) made exclusively positive comments, 146 (42.7%) purely negative comments and 137 (40.0%) offered a mixture of positive and negative. Positive themes included: Daily Coping, Life-Changing/Saving and Stepping Stone. Negative themes included: Physical Adverse Effects, Emotional and Cognitive Blunting, and Withdrawal Effects. Many participants also commented on relationships with prescribers. Collaboration was particularly valued. Negative sub-themes included failings in relation to information (especially about adverse effects and withdrawal), support, and alternatives. Clinicians have a duty to inform potential antidepressant users about positive and adverse effects, including withdrawal effects