scholarly journals Emissions from 3D Printers as Occupational Environmental Pollutants

2021 ◽  
Vol 25 (1) ◽  
pp. 1018-1031
Author(s):  
Ilona Pavlovska ◽  
Žanna Martinsone ◽  
Aneka Kļaviņa ◽  
Lāsma Akūlova ◽  
Linda Paegle
Keyword(s):  
Air Quality ◽  
Ultrafine Particles ◽  
Low Cost ◽  
Background Level ◽  
Medical Personnel ◽  
Ease Of Use ◽  
High Concentration ◽  
Wide Range ◽  
3D Printers ◽  
Mass Concentrations

Abstract While many people work remotely during the pandemic, three-dimensional (3D) printers are working to ensure the medical personnel and general public with the necessary specific materials. Ease of use, low cost, fast prototyping, and a wide range of materials are the advantages of 3D technology that can quickly adapt to specific needs in different application areas and result in increased popularity. The aim was to analyse the concentrations of particulate matter (PM) and volatile organic compounds (VOCs) emitted in 3D printing zone where printers are located throughout the room around the perimeter and where orthopaedics and designers develop models during their full shift. The average ultrafine particles (UFP) concentration level fluctuates from 4×103 to 26×103 particles/cm3 that exceed the background level (<3×103 particles/cm3) during 8 h-shift. Microclimate was evaluated as unsatisfied regarding permissible values for air quality at workplaces: air temperature exceeds permissible upper level +25 °C, relative humidity was 21.5 % and air velocity ≤0.05 m/s. The highest particles’ number concentrations in the nano-scale range (<0.1 μm) and significantly higher mass concentrations in the coarse particle range (>2.5 μm) were detected. The median diameters of particle number (0.019, 0.014, 0.015 μm) and mass concentrations (4.394, 4.433, and 4.677 μm) were similar in all observed premises. Total VOC concentration was increased and specific substances such as toluene and formaldehyde (0.56±0.1 and 0.23±0.034 mg/m3) were found at high concentration in comparison with indoor air quality recommendations.

scholarly journals Developing Relative Humidity and Temperature Corrections for Low-Cost Sensors Using Machine Learning

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3338
Author(s):  
Ivan Vajs ◽  
Dejan Drajic ◽  
Nenad Gligoric ◽  
Ilija Radovanovic ◽  
Ivan Popovic
Keyword(s):  
Machine Learning ◽  
Air Quality ◽  
Relative Humidity ◽  
Low Cost ◽  
Quality Monitoring ◽  
Air Quality Monitoring ◽  
Lower Accuracy ◽  
Wide Range ◽  
The Impact ◽  
Monitoring Stations

Existing government air quality monitoring networks consist of static measurement stations, which are highly reliable and accurately measure a wide range of air pollutants, but they are very large, expensive and require significant amounts of maintenance. As a promising solution, low-cost sensors are being introduced as complementary, air quality monitoring stations. These sensors are, however, not reliable due to the lower accuracy, short life cycle and corresponding calibration issues. Recent studies have shown that low-cost sensors are affected by relative humidity and temperature. In this paper, we explore methods to additionally improve the calibration algorithms with the aim to increase the measurement accuracy considering the impact of temperature and humidity on the readings, by using machine learning. A detailed comparative analysis of linear regression, artificial neural network and random forest algorithms are presented, analyzing their performance on the measurements of CO, NO2 and PM10 particles, with promising results and an achieved R2 of 0.93–0.97, 0.82–0.94 and 0.73–0.89 dependent on the observed period of the year, respectively, for each pollutant. A comprehensive analysis and recommendations on how low-cost sensors could be used as complementary monitoring stations to the reference ones, to increase spatial and temporal measurement resolution, is provided.

Towards a Broad Use of Gamification Based on Hand Tracking in Post Stroke Patients

2019 ◽  
Author(s):  
Daniele Regazzoni ◽  
Andrea Vitali ◽  
Caterina Rizzi
Keyword(s):  
Motion Tracking ◽  
Daily Life ◽  
Low Cost ◽  
Research Work ◽  
Medical Personnel ◽  
Ease Of Use ◽  
Hand Tracking ◽  
Rehabilitation Programs ◽  
Patient Side ◽  
At Home

Abstract In the last years, the advent of innovative technologies for tracking human motions is increasing the interest of physicians and physiotherapist, who would like to introduce new instruments for a more objective assessment of the rehabilitation processes. At present, many motion tracking systems have been developed and their ease of use and low-cost may represent the key aspects for which these systems could be really adopted both in rehabilitation centers and in rehabilitation programs at home. Several research studies confirmed the importance of continuing rehabilitation programs at home with the aim to maintain patients’ health condition at a suitable level for daily life activities. Physicians and physiotherapists need methods and tools, which can be simply adaptable for each type of patients’ category and type of rehabilitation according to the assessed pathology. For achieving this need, the technology has to be suitable for both the patient side and medical personnel side. The most suitable technology for the patients are motion tracking devices which can be used through traditional IT, such as laptops, smartphones and tablets. Also for medical personnel the ease of use is very important, physicians would like to check the patient’s rehab exercises according to their medical knowledge by exploiting daily life technology. This research work investigates on which are the best user-friendly programming tools and low-cost technology for 3D hand and finger tracking for the development of a serious game for rehabilitation exercises. The tasks are designed according to physiotherapists’ recommendations, in order to be customizable for any single user. The following sections will describe the method, the tools adopted, and the application developed.

scholarly journals Green Preparation of Fluorescent Carbon Quantum Dots from Cyanobacteria for Biological Imaging

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 616 ◽  
Author(s):  
Xi Wang ◽  
Pei Yang ◽  
Qian Feng ◽  
Taotao Meng ◽  
Jing Wei ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Source ◽  
Large Scale ◽  
Low Cost ◽  
Average Diameter ◽  
Carbon Quantum Dots ◽  
Water Soluble ◽  
High Concentration ◽  
Wide Range ◽  
Low Cytotoxicity

Biomass-based carbon quantum dots (CQDs) have become a significant carbon materials by their virtues of being cost-effective, easy to fabricate and low in environmental impact. However, there are few reports regarding using cyanobacteria as a carbon source for the synthesis of fluorescent CQDs. In this study, the low-cost biomass of cyanobacteria was used as the sole carbon source to synthesize water-soluble CQDs by a simple hydrothermal method. The synthesized CQDs were mono-dispersed with an average diameter of 2.48 nm and exhibited excitation-dependent emission performance with a quantum yield of 9.24%. Furthermore, the cyanobacteria-derived CQDs had almost no photobleaching under long-time UV irradiation, and exhibited high photostability in the solutions with a wide range of pH and salinity. Since no chemical reagent was involved in the synthesis of CQDs, the as-prepared CQDs were confirmed to have low cytotoxicity for PC12 cells even at a high concentration. Additionally, the CQDs could be efficiently taken up by cells to illuminate the whole cell and create a clear distinction between cytoplasm and nucleus. The combined advantages of green synthesis, cost-effectiveness and low cytotoxicity make synthesized CQDs a significant carbon source and broaden the application of cyanobacteria and provide an economical route to fabricate CQDs on a large scale.

scholarly journals Biotechnology of Rhodococcus for the production of valuable compounds

2020 ◽  
Vol 104 (20) ◽  
pp. 8567-8594 ◽  
Author(s):  
Martina Cappelletti ◽  
Alessandro Presentato ◽  
Elena Piacenza ◽  
Andrea Firrincieli ◽  
Raymond J. Turner ◽  
...  
Keyword(s):  
Waste Disposal ◽  
Low Cost ◽  
Value Added ◽  
Industrial Wastes ◽  
Bioactive Molecules ◽  
High Concentration ◽  
Metabolic Versatility ◽  
Wide Range ◽  
Valuable Compounds ◽  
Medical Relevance

Abstract Bacteria belonging to Rhodococcus genus represent ideal candidates for microbial biotechnology applications because of their metabolic versatility, ability to degrade a wide range of organic compounds, and resistance to various stress conditions, such as metal toxicity, desiccation, and high concentration of organic solvents. Rhodococcus spp. strains have also peculiar biosynthetic activities that contribute to their strong persistence in harsh and contaminated environments and provide them a competitive advantage over other microorganisms. This review is focused on the metabolic features of Rhodococcus genus and their potential use in biotechnology strategies for the production of compounds with environmental, industrial, and medical relevance such as biosurfactants, bioflocculants, carotenoids, triacylglycerols, polyhydroxyalkanoate, siderophores, antimicrobials, and metal-based nanostructures. These biosynthetic capacities can also be exploited to obtain high value-added products from low-cost substrates (industrial wastes and contaminants), offering the possibility to efficiently recover valuable resources and providing possible waste disposal solutions. Rhodococcus spp. strains have also recently been pointed out as a source of novel bioactive molecules highlighting the need to extend the knowledge on biosynthetic capacities of members of this genus and their potential utilization in the framework of bioeconomy. Key points • Rhodococcus possesses promising biosynthetic and bioconversion capacities. • Rhodococcus bioconversion capacities can provide waste disposal solutions. • Rhodococcus bioproducts have environmental, industrial, and medical relevance.

scholarly journals LoRa Sensor Network Development for Air Quality Monitoring or Detecting Gas Leakage Events

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6225
Author(s):  
Ernesto González ◽  
Juan Casanova-Chafer ◽  
Alfonso Romero ◽  
Xavier Vilanova ◽  
Jan Mitrovics ◽  
...  
Keyword(s):  
Air Quality ◽  
Sensor Network ◽  
Low Cost ◽  
Background Level ◽  
Early Warning Systems ◽  
Air Pollutant ◽  
Quality Monitoring ◽  
Air Quality Monitoring ◽  
Gas Leakage ◽  
Events Detection

During the few last years, indoor and outdoor Air Quality Monitoring (AQM) has gained a lot of interest among the scientific community due to its direct relation with human health. The Internet of Things (IoT) and, especially, Wireless Sensor Networks (WSN) have given rise to the development of wireless AQM portable systems. This paper presents the development of a LoRa (short for long-range) based sensor network for AQM and gas leakage events detection. The combination of both a commercial gas sensor and a resistance measurement channel for graphene chemoresistive sensors allows both the calculation of an Air Quality Index based on the concentration of reducing species such as volatile organic compounds (VOCs) and CO, and it also makes possible the detection of NO2, which is an important air pollutant. The graphene sensor tested with the LoRa nodes developed allows the detection of NO2 pollution in just 5 min as well as enables monitoring sudden changes in the background level of this pollutant in the atmosphere. The capability of the system of detecting both reducing and oxidizing pollutant agents, alongside its low-cost, low-power, and real-time monitoring features, makes this a solution suitable to be used in wireless AQM and early warning systems.

scholarly journals The Influence of Humidity on the Performance of Low-Cost Air Particle Mass Sensors and the Effect of Atmospheric Fog

2018 ◽  
Author(s):  
Rohan Jayaratne ◽  
Xiaoting Liu ◽  
Phong Thai ◽  
Matthew Dunbabin ◽  
Lidia Morawska
Keyword(s):  
Air Quality ◽  
Particle Number ◽  
Low Cost ◽  
Quality Standards ◽  
Causal Link ◽  
Solid Particles ◽  
Air Quality Standards ◽  
Mass Sensors ◽  
Adverse Health Effects ◽  
Mass Concentrations

Abstract. While low-cost particle sensors are being increasingly used in numerous applications, most of them have no heater or dryer at the inlet to remove water from the sample before measurement. Deliquescent growth of particles and the formation of fog droplets in the atmosphere can lead to significant increases in particle number concentration (PNC) and mass concentrations reported by such sensors. We carried out a detailed study using a Plantower PMS1003 low-cost particle sensor, both in the laboratory and under actual ambient field conditions, to investigate its response to increasing humidity and the presence of fog in the air. We found significant increases in particle number and mass concentrations at relative humidity above about 75 %. During a period of fog, the total PNC increased by 28 %, while the PNC larger than 2.5 µm increased by over 50 %. The PM10 concentration reported by the PMS1003 was 46 % greater than that on the standard monitor with a charcoal dryer at the inlet. While there is a causal link between particle pollution and adverse health effects, the presence of water on the particles is not harmful to humans. Therefore, air quality standards for particles are specifically limited to solid particles and standard particle monitoring instruments are fitted with a heater or dryer at the inlet to remove all liquid material from the sample before the concentrations are measured. This study shows that, although low-cost sensors can accurately report the particle number and mass concentrations in the environment, it is important to understand that the results cannot be used to ascertain if air quality standards are being met.

scholarly journals Broad-scale Applications of the Raspberry Pi: A Review and Guide for Biologists

2021 ◽  
Author(s):  
Jolle Wolter Jolles
Keyword(s):  
Scientific Community ◽  
Large Scale ◽  
Low Cost ◽  
Ease Of Use ◽  
Plant Phenotyping ◽  
Raspberry Pi ◽  
Ecosystem Monitoring ◽  
Diverse Range ◽  
Wide Range ◽  
Macro Scale

The field of biology has seen tremendous technological progress in recent years, fuelled by the exponential growth in processing power and high-level computing, and the rise of global information sharing. Low-cost single-board computers are predicted to be one of the key technological advancements to further revolutionise this field. So far, an overview of current uptake of these devices and a general guide to help researchers integrate them in their work has been missing. In this paper I focus on the most widely used single board computer, the Raspberry Pi. Reviewing its broad applications and uses across the biological domain shows that since its release in 2012 the Raspberry Pi has been increasingly taken up by biologists, both in the lab, the field, and in the classroom, and across a wide range of disciplines. A hugely diverse range of applications already exist that range from simple solutions to dedicated custom-build devices, including nest-box monitoring, wildlife camera trapping, high-throughput behavioural recordings, large-scale plant phenotyping, underwater video surveillance, closed-loop operant learning experiments, and autonomous ecosystem monitoring. Despite the breadth of its implementations, the depth of uptake of the Raspberry Pi by the scientific community is still limited. The broad capabilities of the Raspberry Pi, combined with its low cost, ease of use, and large user community make it a great research tool for almost any project. To help accelerate the uptake of Raspberry Pi’s by the scientific community, I provide detailed guidelines, recommendations, and considerations, and 30+ step-by-step guides on a dedicated accompanying website (raspberrypi-guide.github.io). I hope with this paper to generate more awareness about the Raspberry Pi and thereby fuel the democratisation of science and ultimately help advance our understanding of biology, from the micro- to the macro-scale.

scholarly journals An Integrated System for Simultaneous Monitoring of Traffic and Pollution Concentration—Lessons Learned for Bielsko-Biała, Poland

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8028
Author(s):  
Krzysztof Brzozowski ◽  
Artur Ryguła ◽  
Andrzej Maczyński
Keyword(s):  
Air Quality ◽  
Meteorological Data ◽  
Low Cost ◽  
Background Level ◽  
Lessons Learned ◽  
Integrated System ◽  
Network Information ◽  
Transit Times ◽  
Pm2.5 And Pm10 ◽  
The Impact

The challenge of maintaining the required level of mobility and air quality in cities can be met by deploying an appropriate management system in which the immediate vicinity of roads is monitored to identify potential pollution hotspots. This paper presents an integrated low-cost system which can be used to study the impact of traffic related emission on air quality at intersections. The system was used for three months in 2017 at five locations covering intersections in the centre of a mid-sized city. Depending on the location, pollution hotspots with high PM2.5 and PM10 concentrations occurred 5–10% of the time. It was shown that despite the close mutual proximity of the locations, traffic and the immediate surroundings lead to significant variation in air quality. At locations with adverse ventilation conditions a tendency towards more frequent occurrences of moderate and sufficient air quality was observed than at other locations (even those with more traffic). Based on the results, a practical extension of the system was also proposed by formulating a model for the prediction of PM2.5 concentration using a neural network. Information on transit times, meteorological data and the background level of PM10 concentration were used as model input parameters.

scholarly journals Characterization of a novel, low-cost, scalable vaporized hydrogen peroxide system for sterilization of N95 respirators and other COVID-19 related personal protective equipment

2020 ◽  
Author(s):  
Nikhil Dave ◽  
Katie Sue Pascavis ◽  
John Patterson ◽  
David Wallace ◽  
Abhik Chowdhury ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Low Cost ◽  
Cost Effective ◽  
Medical Personnel ◽  
Alternative Methods ◽  
Community Members ◽  
Fluid Resistance ◽  
Wide Range ◽  
The Cost ◽  
N95 Respirators

AbstractDue to the virulence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pathogen responsible for the respiratory disease termed COVID-19, there has been a significant increase in demand for surgical masks and N95 respirators in medical clinics as well as within communities operating during the COVID-19 epidemic. Thus, community members, business owners, and even medical personnel have resorted to alternative methods for sterilizing face coverings and N95 respirators for reuse. While significant work has shown that vaporized hydrogen peroxide (VHP) can be used to sterilize N95 respirators, the cost and installation time for these sterilization systems limit their accessibility. To this end, we have designed and constructed a novel, cost-effective, and scalable VHP system that can be used to sterilize N95 respirators and other face coverings for clinical and community applications. N95 respirators inoculated with P22 bacteriophage showed a greater than 6-log10 reduction in viral load when sterilized in the VHP system for one 60-minute cycle. Further, N95 respirators treated with 20 cycles in this VHP system showed comparable filtration efficiency to untreated N95 respirators in a 50 to 200 nanometer particulate challenge filtration test. While a 23% average increase in water droplet roll-off time was observed for N95 respirators treated with 5 cycles in the sterilization, no breakdown in fluid resistance was detected. These data suggest that our VHP system is effective in sterilizing N95 respirators and other polypropylene masks for reuse. Relating to the present epidemic, deployment of this system reduces the risk of COVID-19 community transmission while conserving monetary resources otherwise spent on the continuous purchase of disposable N95 respirators and other face coverings. In summary, this novel, scientifically validated sterilization system can be easily built at a low cost and implemented in a wide range of settings.

scholarly journals Stationary and portable multipollutant monitors for high-spatiotemporal-resolution air quality studies including online calibration

2021 ◽  
Vol 14 (2) ◽  
pp. 995-1013
Author(s):  
Colby Buehler ◽  
Fulizi Xiong ◽  
Misti Levy Zamora ◽  
Kate M. Skog ◽  
Joseph Kohrman-Glaser ◽  
...  
Keyword(s):  
Air Quality ◽  
Low Cost ◽  
Personal Exposure ◽  
Atmospheric Pollutants ◽  
Sensor Data ◽  
Concentration Data ◽  
Spatiotemporal Resolution ◽  
Online Calibration ◽  
High Spatiotemporal Resolution ◽  
Wide Range

Abstract. The distribution and dynamics of atmospheric pollutants are spatiotemporally heterogeneous due to variability in emissions, transport, chemistry, and deposition. To understand these processes at high spatiotemporal resolution and their implications for air quality and personal exposure, we present custom, low-cost air quality monitors that measure concentrations of contaminants relevant to human health and climate, including gases (e.g., O3, NO, NO2, CO, CO2, CH4, and SO2) and size-resolved (0.3–10 µm) particulate matter. The devices transmit sensor data and location via cellular communications and are capable of providing concentration data down to second-level temporal resolution. We produce two models: one designed for stationary (or mobile platform) operation and a wearable, portable model for directly measuring personal exposure in the breathing zone. To address persistent problems with sensor drift and environmental sensitivities (e.g., relative humidity and temperature), we present the first online calibration system designed specifically for low-cost air quality sensors to calibrate zero and span concentrations at hourly to weekly intervals. Monitors are tested and validated in a number of environments across multiple outdoor and indoor sites in New Haven, CT; Baltimore, MD; and New York City. The evaluated pollutants (O3, NO2, NO, CO, CO2, and PM2.5) performed well against reference instrumentation (e.g., r=0.66–0.98) in urban field evaluations with fast e-folding response times (≤ 1 min), making them suitable for both large-scale network deployments and smaller-scale targeted experiments at a wide range of temporal resolutions. We also provide a discussion of best practices on monitor design, construction, systematic testing, and deployment.

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