scholarly journals Assessment of Integrated Aerosol Sampling Techniques in Indoor, Confined and Outdoor Environments Characterized by Specific Emission Sources

2021 ◽  
Vol 11 (10) ◽  
pp. 4360
Author(s):  
Laura Borgese ◽  
Maria Chiesa ◽  
Ahmad Assi ◽  
Claudio Marchesi ◽  
Anne Wambui Mutahi ◽  
...  
Keyword(s):  
Particle Size ◽  
Optical Sensors ◽  
Low Cost ◽  
Reference Method ◽  
Optical Devices ◽  
Cascade Impactor ◽  
Emission Sources ◽  
Aerosol Sampling ◽  
Monitoring Campaign ◽  
Outdoor Environments

This paper highlights advantages and drawbacks due to the use of portable and low-cost devices for aerosol sampling, showing their performances during an aerosol monitoring campaign with the parallel use of the gravimetric sampling reference method and a cascade impactor. A specific monitoring campaign was held running all instruments in parallel in indoor, confined, and outdoor environments characterized by local emission sources or particulate matter background concentrations. PM2.5 concentrations were used to compare data emerging from the different instruments adopted. Significant underestimation of PM2.5 emerged when comparing data coming from optical sensors with those estimated by the cascade impactor, whose data resulted in being coherent with gravimetric determination, integrated over the same sampling time. A cause–effect relationship between PM2.5 concentrations and specific emission sources was found when observing the daily patterns of all the real-time sampling devices. It emerged that optical devices are useful for detecting concentration trends, the presence of peak values, or changes in the background value, even if with limited accuracy and precision. The comparison with particle size distributions obtained by the cascade impactor data allowed us to define which particle sizes are not detected by different optical devices, evidencing a low representativeness of optical low-cost sensors for health exposure measurements. The correlations among the specific particle size fractions detected by the cascade impactor and their specific emission sources were particularly high for car emissions in a semi-confined garage area.

A Simplified Model for the Flow Inside Cascade Impactor

2013 ◽  
Author(s):  
Seyyed Mahdi Nemati Mehr ◽  
Salman Sohrabi ◽  
Pedram Falsafi ◽  
Paniz Gorji
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Low Cost ◽  
Mass Difference ◽  
Cascade Impactor ◽  
Computational Method ◽  
Simplified Model ◽  
Unit Value ◽  
Cascade Impactors

In this paper we developed a new mathematical model for the flow inside cascade impactors and via this simplified model, we determined the particle size distribution by a fast and low cost computational method. Using cascade impactors for determining the particle size distribution, one can use comprehensive CFD methods to fully simulate the particle traces. Although the results from those CFD analyses can be very accurate, usually that is not a time and cost efficient routine. In contrast, we showed that by using our proposed calculation we can estimate the particle size distribution very fast and yet with the slight error — comparing to the results from CFD method. Cascade impactors are being used to measure the range of substances moving through an opening and determine the particle size of distributed substances. Air flow containing aerosol entering in each stage, after colliding vertically with a plate will deviate 90 degrees from its original direction. Larger (massive) particles cannot follow the flow because of their larger linear momentum. Hence, they will deviate from the flow and deposit on the plate instead. The mass difference before and after the experiment represents the deposited mass in each stage. By integrating multiple uniquely designed stages into one impactor, we can determine size of particles in the flow. Typical cascade impactors consist of up to ten stages in which different size of aerosols are being separated. This paper presents a simple model for the flow in one single stage of a cascade impactor. Flow inside cascade impactor is approximated by stagnation point potential flow with the stream function of Psi = Axy, and particles are tracked by velocity verlet algorithm. Absorbed particles are associated with unit value; otherwise they are associated with zero. It is assumed that particles in entrance have random size distribution and location. Drag, Saffman and Brownian forces are taken into account in this model for different particle sizes. The results are discussed in detail and compared with data driven from different approaches in the literature.

scholarly journals Optoelectronic Instrumentation and Measurement Strategies for Optical Chemical (Bio)Sensing

2021 ◽  
Vol 11 (17) ◽  
pp. 7849
Author(s):  
Francisco Ferrero Martín ◽  
Marta Valledor Llopis ◽  
Juan C. Campo Rodríguez ◽  
Alberto López Martínez ◽  
Ana Soldado Cabezuelo ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Chemical Sensors ◽  
Optical Measurement ◽  
Low Cost ◽  
Measurement Techniques ◽  
Optical Devices ◽  
Luminescence Spectroscopy ◽  
Full Understanding ◽  
New Materials ◽  
Measurement Strategies

There is a growing interest in the development of sensitive, portable, and low-cost instrumentation for optical chemical (bio)sensing. Such instrumentation can allow real-time decision-making for industry, farmers, and researchers. The combination of optical fiber schemes, luminescence spectroscopy techniques, and new materials for sensor immobilization has allowed the growth of optical sensors. This article focuses on the development of low-cost optoelectronic instrumentation and measurement strategies for optical chemical (bio)sensing. Most of the articles in this field have focused on the chemical sensors themselves, although few have covered the design process for optoelectronic instrumentation. This article tries to fill this gap by presenting designs for real applications, as carried out by the authors. We also offer an introduction to the optical devices and optical measurement techniques used in this field to allow a full understanding of the applications.

scholarly journals Quantification and Classification of Diclofenac Sodium Content in Dispersed Commercially Available Tablets by Attenuated Total Reflection Infrared Spectroscopy and Multivariate Data Analysis

2021 ◽  
Vol 14 (5) ◽  
pp. 440
Author(s):  
Eirini Siozou ◽  
Vasilios Sakkas ◽  
Nikolaos Kourkoumelis
Keyword(s):  
Infrared Spectroscopy ◽  
Low Cost ◽  
Diclofenac Sodium ◽  
Reference Method ◽  
Sodium Content ◽  
Attenuated Total Reflection ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Ft Ir

A new methodology, based on Fourier transform infrared spectroscopy equipped with an attenuated total reflectance accessory (ATR FT-IR), was developed for the determination of diclofenac sodium (DS) in dispersed commercially available tablets using chemometric tools such as partial least squares (PLS) coupled with discriminant analysis (PLS-DA). The results of PLS-DA depicted a perfect classification of the tablets into three different groups based on their DS concentrations, while the developed model with PLS had a sufficiently low root mean square error (RMSE) for the prediction of the samples’ concentration (~5%) and therefore can be practically used for any tablet with an unknown concentration of DS. Comparison with ultraviolet/visible (UV/Vis) spectrophotometry as the reference method revealed no significant difference between the two methods. The proposed methodology exhibited satisfactory results in terms of both accuracy and precision while being rapid, simple and of low cost.

scholarly journals Thermogravimetric Analysis (TGA) of Graphene Materials: Effect of Particle Size of Graphene, Graphene Oxide and Graphite on Thermal Parameters

2021 ◽  
Vol 7 (2) ◽  
pp. 41
Author(s):  
Farzaneh Farivar ◽  
Pei Lay Yap ◽  
Ramesh Udayashankar Karunagaran ◽  
Dusan Losic
Keyword(s):  
Particle Size ◽  
Quality Control ◽  
Graphene Oxide ◽  
Thermogravimetric Analysis ◽  
Low Cost ◽  
Thermal Parameters ◽  
Carbon Decomposition ◽  
Size Number ◽  
Carbon Combustion ◽  
Oxygen Groups

Thermogravimetric analysis (TGA) has been recognized as a simple and reliable analytical tool for characterization of industrially manufactured graphene powders. Thermal properties of graphene are dependent on many parameters such as particle size, number of layers, defects and presence of oxygen groups to improve the reliability of this method for quality control of graphene materials, therefore it is important to explore the influence of these parameters. This paper presents a comprehensive TGA study to determine the influence of different particle size of the three key materials including graphene, graphene oxide and graphite on their thermal parameters such as carbon decomposition range and its temperature of maximum mass change rate (Tmax). Results showed that Tmax values derived from the TGA-DTG carbon combustion peaks of these materials increasing from GO (558–616 °C), to graphene (659–713 °C) and followed by graphite (841–949 °C) The Tmax values derived from their respective DTG carbon combustion peaks increased as their particle size increased (28.6–120.2 µm for GO, 7.6–73.4 for graphene and 24.2–148.8 µm for graphite). The linear relationship between the Tmax values and the particle size of graphene and their key impurities (graphite and GO) confirmed in this study endows the use of TGA technique with more confidence to evaluate bulk graphene-related materials (GRMs) at low-cost, rapid, reliable and simple diagnostic tool for improved quality control of industrially manufactured GRMs including detection of “fake” graphene.

scholarly journals Flexible and Low-Cost Fabrication of Optical Waveguides Based on Sno2 for Passive Optical Devices

2021 ◽  
Vol 1805 (1) ◽  
pp. 012043
Author(s):  
Asnawi ◽  
N A Siddiq ◽  
M S Muntini ◽  
Y H Pramono
Keyword(s):  
Optical Waveguides ◽  
Low Cost ◽  
Optical Devices

Effect of Kaolin Particle Size Towards Preparation of Kaolin Ceramic Membrane

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
Siti Khadijah Hubadillah ◽  
◽  
Norsiah Hami ◽  
Nurul Azita Salleh ◽  
Mohd Riduan Jamalludin ◽  
...  
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Preliminary Data ◽  
Membrane Structure ◽  
Ceramic Membrane ◽  
Low Cost ◽  
Dense Structure ◽  
Scanning Electron

The purpose of this work is to study the effect of kaolin particle size for the preparation of low cost ceramic membrane suspension and ceramic membrane structure. Kaolin particle size is categorized into two categories; i) ≤ 1µm and ii) ≥ 1 µm. The suspension is prepared via stirring technique under 1000 rpm at 60°C. The particle size of kaolin is characterized using field emission scanning electron microscope (FESEM) and the prepared suspension is characterized in term of its viscosity. Results indicate that the particle size gave significant effect to the viscosity of ceramic membrane suspension. Preliminary data showed that kaolin with particle size ≤ 1µm resulted ceramic membrane with dense structure.

Characterization of the emission behavior of pulse-jet cleaned filters using a low-cost particulate matter sensor/Charakterisierung der Emission von druckstoßgereinigten Oberflächenfiltern mit einem Low-Cost-Feinstaubsensor

Gefahrstoffe ◽  
2019 ◽  
Vol 79 (11-12) ◽  
pp. 443-450
Author(s):  
P. Bächler ◽  
J. Meyer ◽  
A. Dittler
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Low Cost ◽  
Particle Emission ◽  
Filter Medium ◽  
Emission Measurement ◽  
Pm2.5 Concentration ◽  
Pulse Jet

The reduction of fine dust emissions with pulse-jet cleaned filters plays an important role in industrial gas cleaning to meet emission standards and protect the environment. The dust emission of technical facilities is typically measured “end of pipe”, so that no information about the local emission contribution of individual filter elements exists. Cheap and compact low-cost sensors for the detection of particulate matter (PM) concentrations, which have been prominently applied for immission monitoring in recent years have the potential for emission measurement of filters to improve process monitoring. This publication discusses the suitability of a low-cost PM-sensor, the model SPS30 from the manufacturer Sensirion, in terms of the potential for particle emission measurement of surface filters in a filter test rig based on DIN ISO 11057. A Promo® 2000 in combination with a Welas® 2100 sensor serves as the optical reference device for the evaluation of the detected PM2.5 concentration and particle size distribution of the emission measured by the low-cost sensor. The Sensirion sensor shows qualitatively similar results of the detected PM2.5 emission as the low-cost sensor SDS011 from the manufacturer Nova Fitness, which was investigated by Schwarz et al. in a former study. The typical emission peak after jet-pulse cleaning of the filter, due to the penetration of particles through the filter medium, is detected during Δp-controlled operation. The particle size distribution calculated from the size resolved number concentrations of the low-cost sensor yields a distinct distribution for three different employed filter media and qualitatively fits the size distribution detected by the Palas® reference. The emission of these three different types of filter media can be distinguished clearly by the measured PM2.5 concentration and the emitted mass per cycle and filter area, demonstrating the potential for PM emission monitoring by the low-cost PM-sensor. During the period of Δt-controlled filter aging, a decreasing emission, caused by an increasing amount of stored particles in the filter medium, is detected. Due to the reduced particle emission after filter aging, the specified maximum concentration of the low-cost sensor is not exceeded so that coincidence is unlikely to affect the measurement results of the sensor for all but the very first stage of filter life.

Microbial-Induced Mineralization of Zinc Ions Based on the Degradation of Toluene and Its Characterization

2021 ◽  
Vol 13 (4) ◽  
pp. 656-661
Author(s):  
Yiyan Lv ◽  
Qiwei Zhan ◽  
Xiaoniu Yu
Keyword(s):  
Particle Size ◽  
Phase Composition ◽  
Surface Morphology ◽  
Organic Compounds ◽  
Low Cost ◽  
Zinc Ion ◽  
Zinc Ions ◽  
Quick Response ◽  
Zinc Carbonate ◽  
Carbonate Ions

Microbial-induced degradation of aromatic organic compounds and mineralization of zinc ions have attracted much attention because of its low cost, simple operation and quick response. This research, toluene was decomposed and made the concentration of carbonate ions increased accordingly by the enzymatic pressing of microorganisms, meanwhile carbonate ions mineralized zinc ions into carbonate precipitations. The composition and microstructure were analyzed systematically. The analysis results indicated that carbonate precipitations, basic zinc carbonate, could be successfully prepared by microbial method. The particle size of basic zinc carbonate was nanometer, and its shape was near-spherical. Furthermore, the phase composition, functional groups and surface morphology of the precipitations prepared by different methods were basically the same. This work provided a new method for remediation of zinc ion pollution based on the degradation of toluene.

scholarly journals Modelling of new generation plasma optical devices

Nukleonika ◽  
2016 ◽  
Vol 61 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Irina V. Litovko ◽  
Alexy A. Goncharov ◽  
Andrew N. Dobrovolskiy ◽  
Lily V. Naiko ◽  
Irina V. Naiko
Keyword(s):  
Low Cost ◽  
Rocket Engine ◽  
Cost Effective ◽  
Optical Devices ◽  
High Tech ◽  
Practical Applications ◽  
Plasma Accelerators ◽  
New Generation ◽  
Closed Electron ◽  
Positive Space

Abstract The paper presents new generation plasma optical devices based on the electrostatic plasma lens configuration that opens a novel attractive possibility for effective high-tech practical applications. Original approaches to use of plasma accelerators with closed electron drift and open walls for the creation of a cost-effective low-maintenance plasma lens with positive space charge and possible application for low-cost, low-energy rocket engine are described. The preliminary experimental, theoretical and simulation results are presented. It is noted that the presented plasma devices are attractive for many different applications in the state-of-the-art vacuum-plasma processing.

scholarly journals Synchronous fluorescence as a green and selective tool for simultaneous determination of bambuterol and its main degradation product, terbutaline

2018 ◽  
Vol 5 (10) ◽  
pp. 181359 ◽  
Author(s):  
Samah Abo El Abass ◽  
Heba Elmansi
Keyword(s):  
Degradation Product ◽  
Low Cost ◽  
Reference Method ◽  
Cost Effective ◽  
Zero Crossing ◽  
Cost Effective Method ◽  
Validation Parameters ◽  
Main Degradation Product ◽  
20 Nm

A green, sensitive and cost-effective method is introduced in this research for the determination of bambuterol and its main degradation product, terbutaline, simultaneously, relying on the synchronous spectrofluorimetric technique. First derivative synchronous spectrofluorimetric amplitude is measured at Δ λ = 20 nm, so bambuterol can be quantitated at 260 nm, and terbutaline can be measured at 290 nm, each at the zero crossing point of the other. The amplitude–concentration plots were linear over the concentration ranges of 0.2–6.0 µg ml −1 and 0.2–4.0 µg ml −1 for both bambuterol and terbutaline, respectively. Official guidelines were followed to calculate the validation parameters of the proposed method. The low values of limits of detection of 0.023, 0.056 µg ml −1 and limits of quantitation of 0.071, 0.169 µg ml −1 for bambuterol and terbutaline, respectively, point to the sensitivity of the method. Bambuterol is a prodrug for terbutaline, and the latter is considered its degradation product so the established method could be regarded as a stability-indicating one. Moreover, the proposed method was used for the analysis of bambuterol and terbutaline in their single ingredient preparations and the results revealed statistical agreement with the reference method. The suggested method, being a simple and low-cost procedure, is superior to the previously published methods which need more sophisticated techniques, longer analysis time and highly toxic solvents and reagents. It could be considered as an eco-friendly analytical procedure.

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