scholarly journals Analysis of the visibility and signal strength of the LoRaWAN network in an urbanized area – a case study of the Bielany campus at the Nicolaus Copernicus University in Toruń

2021 ◽  
Vol 54 (54) ◽  
pp. 137-149
Author(s):  
Dominika Karpińska ◽  
Mieczysław Kunz
Keyword(s):  
High Sensitivity ◽  
Environmental Data ◽  
Network Access ◽  
Data Logger ◽  
Measuring Device ◽  
Pollution Levels ◽  
Custom Made ◽  
Night Sky ◽  
Distributed Measurement ◽  
Nicolaus Copernicus

Abstract In order to assess or determine the overall quality of the surrounding geographical environment, it is necessary to measure selected factors that directly or indirectly affect its condition. The aspects to be monitored include i.a. air pollution levels, surface water purity, soil erosion rates, as well as night sky light pollution, a phenomenon increasingly often observed with the unaided eye. To collect data on the night sky brightness on a regular basis, a remote measuring device was designed and constructed using specialised electronic components, wireless communication, programming code, a high-sensitivity digital light data logger and custom-made programme code. LPWAN networks, including LoRa technology, were developed to support a number of mobile devices where long wireless operation is a priority. To determine the potential use of LoRa technology, as well as to plan the target locations of network access gates (gateways) and the deployment of measuring devices for the collection of environmental data, tests of signal coverage and signal visibility, including measurements of its strength, were carried out in a selected, compact part of the city of Toruń. The paper presents the results of research on the visibility of the LoRa network in a built-up area, such as a university campus, using antennas of two different lengths. The obtained results can be used to design distributed measurement networks in areas with varying density of buildings.

scholarly journals Mid-infrared photoacoustic gas monitoring driven by a gas-filled hollow-core fiber laser

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yazhou Wang ◽  
Yuyang Feng ◽  
Abubakar I. Adamu ◽  
Manoj K. Dasa ◽  
J. E. Antonio-Lopez ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Laser Source ◽  
High Signal ◽  
Mid Infrared ◽  
Raman Fiber Laser ◽  
Custom Made ◽  
Core Fiber ◽  
Detection Technologies

AbstractDevelopment of novel mid-infrared (MIR) lasers could ultimately boost emerging detection technologies towards innovative spectroscopic and imaging solutions. Photoacoustic (PA) modality has been heralded for years as one of the most powerful detection tools enabling high signal-to-noise ratio analysis. Here, we demonstrate a novel, compact and sensitive MIR-PA system for carbon dioxide (CO2) monitoring at its strongest absorption band by combining a gas-filled fiber laser and PA technology. Specifically, the PA signals were excited by a custom-made hydrogen (H2) based MIR Raman fiber laser source with a pulse energy of ⁓ 18 μJ, quantum efficiency of ⁓ 80% and peak power of ⁓ 3.9 kW. A CO2 detection limit of 605 ppbv was attained from the Allan deviation. This work constitutes an alternative method for advanced high-sensitivity gas detection.

scholarly journals Orthodontic Aligner Incorporating Eucommia ulmoides Exerts Low Continuous Force: In Vitro Study

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4085
Author(s):  
Sayuri Inoue ◽  
Satoshi Yamaguchi ◽  
Hiroshi Uyama ◽  
Takashi Yamashiro ◽  
Satoshi Imazato
Keyword(s):  
Water Immersion ◽  
In Vitro Study ◽  
Nickel Titanium ◽  
Orthodontic Appliances ◽  
Orthodontic Appliance ◽  
Measuring Device ◽  
Orthodontic Force ◽  
Custom Made ◽  
Titanium Wire

The aim of this study was to investigate the orthodontic force exerted by thermoplastic orthodontic appliances incorporating Eucommiaulmoides in terms of usefulness as the aligner-type orthodontic device. Erkodur, Essix C+®, Eucommia elastomer, and edgewise brackets were used (n = 3, each; thickness = 1.0 mm, each). The orthodontic force on the upper right incisor was measured every 24 h for two weeks using a custom-made measuring device. The force of the Eucommia elastomer (4.25 ± 0.274 N) and multi bracket system (5.32 ± 0.338 N) did not change from the beginning to the end (p > 0.01). The orthodontic force exerted by the Eucommia elastomer was lower than that of the multi-bracket orthodontic appliance from the beginning to the end. The force of Erkodur significantly decreased from the beginning to 24 h (6.47 ± 1.40 N) and 48 h (3.30 ± 0.536 N) (p < 0.01). The force of Essix C+® significantly decreased from the beginning (13.2 ± 0.845 N) to 24 h (8.77 ± 0.231 N) (p < 0.01). The thermoplastic orthodontic appliance made of Eucommia elastomer continuously exerted a constant orthodontic force for two weeks under water immersion conditions. The orthodontic force of Eucommia elastomer was found to be similar to the orthodontic force exerted by the multi-bracket orthodontic appliance with 0.019 × 0.025 in nickel–titanium wire. These results suggest that the Eucommia elastomer has possibly become one of the more useful materials to form thermoplastic orthodontic appliance exerting low continues orthodontic force.

Sensor Fused Blood Pressure Measuring Device Capable of Recording Korotkoff Sounds in Inflationary Curves

2020 ◽  
Author(s):  
Enrique Alvarez Vazquez ◽  
Daniel Ewert ◽  
Dave Jorgenson ◽  
Michael Sand
Keyword(s):  
Blood Pressure ◽  
Cuff Pressure ◽  
High Sensitivity ◽  
Skin Surface ◽  
Pressure System ◽  
Measuring Device ◽  
Arterial Blood ◽  
Pressure Cuff ◽  
System 2 ◽  
Control Electronics

Abstract This study describes a non-invasive medical device capable of measuring arterial blood pressure (BP) with a combination of inflationary and deflationary procedures. The device uses the pressure cuff pressure signal, arterial skin-surface acoustics, and photoplethysmography (PPG) to make a sensor-fusion estimation of blood pressure readings. We developed an apparatus composed of 1) a modified off-the-shelf oscillometric blood pressure system, 2) a contact microphone with an amplifier, 3) and high-sensitivity pulse oximeter, and its control electronics.

Novel Ultrasonographic Thickness and Strength Assessments of the Flexor Digitorum: A Reliability Analysis

2021 ◽  
Vol 36 (4) ◽  
pp. 269-278
Author(s):  
Christos I Ioannou ◽  
Franziska L Hodde-Chriske ◽  
Marios N Avraamides ◽  
Eckart Altenmüller
Keyword(s):  
High Sensitivity ◽  
Extensor Digitorum ◽  
Retest Reliability ◽  
Custom Made ◽  
Smallest Detectable Change ◽  
The Mean ◽  
The Right ◽  
Flexor Digitorum ◽  
Clinical Conditions ◽  
Test Retest Reliability

OBJECTIVES: Clinical conditions such as focal dystonia often require the assessment of atrophy and weakness of the finger muscles. However, due to a lack of well-established protocols, the current investigation focused on assessing the reliability of thickness and strength assessments of the flexor digitorum (FD) muscle, including both the superficialis and profundus components. As a secondary assessment, the reliability of the strength measurement of the extensor digitorum muscle was examined as well. METHODS: Different thickness measurements of the FD were taken via ultrasonography and averaged to estimate the mean thickness of the FD. Likewise, individual finger strength measurements taken by a custom-made finger pressure device were averaged to compute the mean strength of the flexor and extensor digitorum muscles. Test-retest reliability of the above measurements performed at two different time points (about 6 months apart) were examined on the right and left hands of 10 participants. RESULTS: Findings indicated excellent test-retest reliability (ICC > 0.92) for the mean thickness assessment of the FD and mean strength of the flexor and extensor digitorum for both dominant and non-dominant hands. The standard error of measurement was ≤4.3% for all three mean assessments, indicating high sensitivity. Likewise, the smallest detectable change was also sufficiently small for the mean thickness and mean strength of the flexor digitorum (≤5.1%) and moderately small (≤12%) for the strength of the extensor digitorum. CONCLUSIONS: Results indicated an excellent relative and absolute reliability, for both hands, for the mean thickness and strength assessments of the flexor digitorum muscle and for the mean strength of the extensor digitorum (measured for both hands). These measurements can be used for future investigations and can contribute to the establishment of more precise methods for assessing the muscles in the forearms which serve the hand.

scholarly journals Emission spectra of light-pollution sources determined from the light-scattering spectrometry of the night sky

2019 ◽  
Vol 491 (4) ◽  
pp. 5586-5594
Author(s):  
Miroslav Kocifaj ◽  
František Kundracik ◽  
Ondrej Bilý
Keyword(s):  
Light Scattering ◽  
Field Experiments ◽  
Spectral Composition ◽  
Emission Spectra ◽  
Pollution Sources ◽  
Light Pollution ◽  
Ambient Atmosphere ◽  
Artificial Light ◽  
Measuring Device ◽  
Night Sky

ABSTRACT The emission spectrum of a light-pollution source is a determining factor for modelling artificial light at night. The spectral composition of skyglow is normally derived from the initial spectra of all artificial light sources contributing to the diffuse illumination of an observation point. However, light scattering in the ambient atmosphere imposes a wavelength-specific distortion on the optical signals captured by the measuring device. The nature of the emission, the spectra and the light-scattering phenomena not only control the spectral properties of the ground-reaching radiation, but also provide a unique tool for remote diagnosis and even identification of the emission spectra of the light-polluting sources. This is because the information contained in the night-sky brightness is preferably measured in directions towards a glowing dome of light over the artificial source of light. We have developed a new method for obtaining the emission spectra using remote terrestrial sensing of the bright patches of sky associated with a source. Field experiments conducted in Vienna and Bratislava have been used to validate the theoretical model and the retrieval method. These experiments demonstrate that the numerical inversion is successful even if the signal-to-noise ratio is small. The method for decoding the emission spectra by the light-scattering spectrometry of a night sky is a unique approach that enables for (i) a systematic characterization of the light-pollution sources over a specific territory, and (ii) a significant improvement in the numerical prediction of skyglow changes that we can expect at observatories.

scholarly journals High Resolution Brillouin Sensing of Micro-Scale Structures

2018 ◽  
Vol 8 (12) ◽  
pp. 2572 ◽  
Author(s):  
Atiyeh Zarifi ◽  
Birgit Stiller ◽  
Moritz Merklein ◽  
Benjamin Eggleton
Keyword(s):  
Spatial Resolution ◽  
Measurement Techniques ◽  
High Sensitivity ◽  
Photonic Devices ◽  
Small Dimension ◽  
Detection Techniques ◽  
Micro Scale ◽  
Scale Structures ◽  
Distributed Measurement ◽  
On Chip

Brillouin distributed measurement techniques have been extensively developed for structural health monitoring using fibre optic nerve systems. The recent advancement in the spatial resolution capabilities of correlation-based Brillouin distributed technique have reached the sub-mm regime, making this approach a suitable candidate for monitoring and characterizing integrated photonic devices. The small dimension associated with the short length of these devices—on the order of the cm- and mm-scale—requires high sensitivity detection techniques and sub-mm spatial resolution. In this paper, we provide an overview of the different Brillouin sensing techniques in various micro-scale structures such as photonic crystal fibres, microfibres, and on-chip waveguides. We show how Brillouin sensing is capable of detecting fine transverse geometrical features with the sensitivity of a few nm and also extremely small longitudinal features on the order of a few hundreds of μ m . We focus on the technique of Brillouin optical correlation domain analysis (BOCDA), which enables such high spatial resolution for mapping the opto-acoustic responses of micro-scale waveguides.

scholarly journals Implementation and Integration of Microbial Source Tracking in a River Watershed Monitoring Plan

2019 ◽  
Author(s):  
Elisenda Ballesté ◽  
Katalin Demeter ◽  
Bartholomew Masterson ◽  
Natàlia Timoneda ◽  
Wim G. Meijer
Keyword(s):  
Land Use ◽  
Environmental Parameters ◽  
High Sensitivity ◽  
Significant Negative Correlation ◽  
Microbial Source Tracking ◽  
Environmental Data ◽  
Source Tracking ◽  
Sources Of Pollution ◽  
Set Up ◽  
Human Pollution

AbstractFecal pollution of water bodies poses a serious threat for public health and ecosystems. Microbial source tracking (MST) using host specific bacteria are used to track the source of this potential pollution and be able to perform a better management of the pollution at the source. In this study we tested 12 molecular MST markers to track human, ruminant, sheep, horse, pig and gull pollution to determine their usefulness in their application for an effective management of water quality. First, the potential of the selected markers to track the source was evaluated using fresh fecal samples. Subsequently, we evaluated their performance in a catchment with different impacts, considering land use and environmental conditions. All MST markers showed high sensitivity and specificity, although none achieved 100% for both. Although some of the MST markers were detected in hosts other than the intended ones, their abundance in the target group was always several orders of magnitude higher than in the non-target hosts, demonstrating their suitability to distinguish between sources of pollution. The MST analysis matched the land use in the watershed allowing a very accurate assessment of the main hazards and sources of pollution, in this case mainly human and ruminant pollution. Correlating environmental parameters like temperature and rainfall with the levels of the MST markers provided insight into the dynamics of the pollution along the catchment. The levels of the human associated marker showed a significant negative correlation with rainfall in human polluted areas suggesting a dilution of the pollution, whereas at agricultural areas the ruminant marker increased with rainfall. There were no seasonal differences in the levels of human marker, indicating human pollution as a constant pressure throughout the year, whereas the levels of the ruminant marker was influenced by the seasons, being more abundant in summer and autumn. Performing MST analysis integrated with land uses and environmental data can improve the management of fecal polluted areas and set up good practices.

scholarly journals Low-Cost and Scalable Platform with Multiplexed Microwell Array Biochip for Rapid Diagnosis of COVID-19

Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yang Wang ◽  
Kaiju Li ◽  
Gaolian Xu ◽  
Chuan Chen ◽  
Guiqin Song ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Reverse Transcriptase ◽  
Low Cost ◽  
High Sensitivity ◽  
High Specificity ◽  
Rapid Diagnosis ◽  
Negative Patient ◽  
Microwell Array ◽  
Custom Made ◽  
User Friendly

Sensitive detection of SARS-CoV-2 is of great importance for inhibiting the current pandemic of COVID-19. Here, we report a simple yet efficient platform integrating a portable and low-cost custom-made detector and a novel microwell array biochip for rapid and accurate detection of SARS-CoV-2. The instrument exhibits expedited amplification speed that enables colorimetric read-out within 25 minutes. A polymeric chip with a laser-engraved microwell array was developed to process the reaction between the primers and the respiratory swab RNA extracts, based on reverse transcriptase loop-mediated isothermal amplification (RT-LAMP). To achieve clinically acceptable performance, we synthesized a group of six primers to identify the conserved regions of the ORF1ab gene of SARS-CoV-2. Clinical trials were conducted with 87 PCR-positive and 43 PCR-negative patient samples. The platform demonstrated both high sensitivity (95.40%) and high specificity (95.35%), showing potentials for rapid and user-friendly diagnosis of COVID-19 among many other infectious pathogens.

Nuclear Activation Techniques for Heavy Metal Pollutants

1970 ◽  
Vol 5 (1) ◽  
pp. 9-33
Author(s):  
R.E. Jervis ◽  
B. Tiefenbach ◽  
W. LePage ◽  
J-L Debrun
Keyword(s):  
Toxic Metals ◽  
Feeding Habits ◽  
Water System ◽  
High Sensitivity ◽  
Mercury Content ◽  
Pollution Level ◽  
Pollution Levels ◽  
Analysis Technique ◽  
Fish Samples

Abstract The sensitive radioactivation analysis technique has considerable scope for application in environmental studies. In this paper the use of the applied nuclear method for the determination of nanogram to microgram quantities of several toxic metals (such as F, As, Se, Cd, Hg and Th) in environmental materials, is reported. In typical analyses, samples 0.05 to 0.5 grams in weight have been irradiated for periods up to 50 hours in the McMaster Reactor at approximately 1013 neutrons/cm2 sec thermal neutron flux. With certain samples the identification and determination of trace metal has been accomplished quickly and with high sensitivity by the use of instrumental or non-destructive g-ray spectrometry, while in certain other samples containing metals at lower concentrations, the analysis was facilitated by the use of a few radiochemical separation steps. The mercury content of fish samples taken from various water bodies in Ontario and elsewhere has been determined in the concentration range from 0.01 to 2 ppm. The levels found have been tentatively related to the particular species of fish and their feeding habits as well as to the pollution level in the water system. Similar pollution levels of Se and As have been determined in areas suspected of industrial pollution, and hair activation analyses have been used to monitor human ingestion of these and other toxic metals. A novel on-stream method for the detection of trace levels of metals such as Th and U is also outlined and its application to water pollutants such as P is discussed.

Hydraulics of backflushing for efficiently cleaning hydropower trash racks

2014 ◽  
Vol 41 (3) ◽  
pp. 263-269 ◽  
Author(s):  
Hanne Nøvik ◽  
Leif Lia ◽  
Bjørnar Rettedal ◽  
Lars Eid Nielsen
Keyword(s):  
Pressure Difference ◽  
Small Hydropower ◽  
Measuring Device ◽  
Hydropower Plants ◽  
Custom Made ◽  
Large Measurement ◽  
Efficient Alternative ◽  
Approach Velocity ◽  
First Time

Backflushing is an efficient alternative for cleaning trash racks at small hydropower plants. The actual debris to trash rack adhesion is measured in situ for the first time by an innovative, custom-made measuring device. Despite large measurement variations caused by unevenness in debris distribution, the adhesion to trash rack for most types of debris and for most sites is relatively modest. There is also a trend where a higher maximum head loss through the trash rack increases the debris adhesion to the trash rack. The hydraulics around the trash rack during a backflushing process is assessed by monitoring the velocity development and the pressure difference through the trash rack in a physical model. As expected, when debris adhesion to the trash rack is high, releasing the attached debris requires a higher pressure difference through the trash rack and a higher approach velocity.

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