15 research outputs found

    Do TETRA (Airwave) base station signals have a short-term impact on health and well-being? A randomized double-blind provocation study

    Get PDF
    Background: "Airwave" is the new communication system currently being rolled out across the United Kingdom for the police and emergency services, based on the Terrestrial Trunked Radio Telecommunications System (TETRA). Some police officers have complained about skin rashes, nausea, headaches, and depression as a consequence of using their Airwave handsets. In addition, a small subgroup in the population self-report being sensitive to electromagnetic fields (EMFs) in general. Objectives: We conducted a randomized double-blind provocation study to establish whether short-term exposure to a TETRA base station signal has an impact on the health and well-being of individuals with self-reported "electrosensitivity" and of participants who served as controls.Methods: Fifty-one individuals with self-reported electrosensitivity and 132 age and sex-matched controls participated in an open provocation test; 48 sensitive and 132 control participants went on to complete double-blind tests in a fully screened semianechoic chamber. Heart rate, skin conductance, and blood pressure readings provided objective indices of short-term physiological response. Visual analog scales and symptom scales provided subjective indices of well-being.Results: We found no differences on any measure between TETRA and sham (no signal) under double-blind conditions for either controls or electrosensitive participants, and neither group could detect the presence of a TETRA signal at rates greater than chance (50%). When conditions were not double blind, however, the self-reported electrosensitive individuals did report feeling worse and experienced more severe symptoms during TETRA compared with sham.Conclusions: Our findings suggest that the adverse symptoms experienced by electrosensitive individuals are due to the belief of harm from TETRA base stations rather than to the low-level EMF exposure itself

    Does Short-Term Exposure to Mobile Phone Base Station Signals Increase Symptoms in Individuals Who Report Sensitivity to Electromagnetic Fields? A Double-Blind Randomized Provocation Study

    Get PDF
    BACKGROUND: Individuals with idiopathic environmental illness with attribution to electromagnetic fields (IEI-EMF) believe they suffer negative health effects when exposed to electromagnetic fields from everyday objects such as mobile phone base stations. OBJECTIVES: This study used both open provocation and double-blind tests to determine if sensitive and control individuals experience more negative health effects when exposed to base station-like signals compared with sham. METHODS: Fifty-six self-reported sensitive and 120 control participants were tested in an open provocation test. Of these, 12 sensitive and 6 controls withdrew after the first session. The remainder completed a series of double-blind tests. Subjective measures of well-being and symptoms as well as physiological measures of blood volume pulse, heart rate, and skin conductance were obtained. RESULTS: During the open provocation, sensitive individuals reported lower levels of well-being in both the global system for mobile communication (GSM) and universal mobile telecommunications system (UMTS) compared with sham exposure, whereas controls reported more symptoms during the UMTS exposure. During double-blind tests the GSM signal did not have any effect on either group. Sensitive participants did report elevated levels of arousal during the UMTS condition, whereas the number or severity of symptoms experienced did not increase. Physiological measures did not differ across the three exposure conditions for either group. CONCLUSIONS: Short-term exposure to a typical GSM base station-like signal did not affect well-being or physiological functions in sensitive or control individuals. Sensitive individuals reported elevated levels of arousal when exposed to a UMTS signal. Further analysis, however, indicated that this difference was likely to be due to the effect of order of exposure rather than the exposure itself

    Drop Traffic in Microfluidic Ladder Networks with Fore-Aft Structural Asymmetry

    Full text link
    We investigate the dynamics of pairs of drops in microfluidic ladder networks with slanted bypasses, which break the fore-aft structural symmetry. Our analytical results indicate that unlike symmetric ladder networks, structural asymmetry introduced by a single slanted bypass can be used to modulate the relative drop spacing, enabling them to contract, synchronize, expand, or even flip at the ladder exit. Our experiments confirm all these behaviors predicted by theory. Numerical analysis further shows that while ladder networks containing several identical bypasses are limited to nearly linear transformation of input delay between drops, mixed combination of bypasses can cause significant non-linear transformation enabling coding and decoding of input delays.Comment: 4 pages, 5 figure

    Droplet group production in an AC electro-flow-focusing microdevice

    Get PDF
    We report the production of droplet groups with a controlled number of drops in a microfluidic electro-flow focusing device under the action of an AC electric field. This regime appears for moderate voltages (500-700 V peak-to-peak) and signal frequencies between 25 and 100 Hz, much smaller than the droplet production rate ( ≈500 Hz). For this experimental conditions the production frequency of a droplet package is twice the signal frequency. Since the continuous phase flow in the microchannel is a Hagen-Poiseuille flow, the smaller droplets of a group move faster than the bigger ones leading to droplet clustering downstream.Ministerio de Economía y Competitividad DPI2013-46485-C3-1-RMinisterio de Economía y Competitividad FIS2014-54539- PJunta de Andalucía P11-FQM-791

    Smart cell planning and optimisation for UMTS

    No full text
    In this paper we introduce an automatic cell planning and optimisation tool called CDSSmartPlan. This is one of a very limited number of automatic cell planning tools which has the capability to plan for UMTS. CDSSmartPlan is powered by a modular heuristic optimisation engine, which is completely autonomous in the cell planning process. A modular software design facilitates "plug-in" bespoke key performance indicators (KPI) and different modelling elements. We present a case study for UMTS network design in London using CDSSmartPlan. Detailed results are presented for a range of KPI

    Derivation of Atmospheric Properties Using a Radio Occultation Technique

    No full text
    corecore