scholarly journals A Ratiometric Optical Dual Sensor for the Simultaneous Detection of Oxygen and Carbon Dioxide

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4057
Author(s):  
Divyanshu Kumar ◽  
Cheng-Shane Chu
Keyword(s):  
Carbon Dioxide ◽  
Quantum Dots ◽  
Fluorescence Intensity ◽  
Simultaneous Detection ◽  
Phenol Red ◽  
New Approach ◽  
Dual Sensor ◽  
Response And Recovery ◽  
Carbon Dioxide Co2 ◽  
Spectral Intensities

Simultaneous detection of carbon dioxide (CO2) and oxygen (O2) has attracted considerable interest since CO2 and O2 play key roles in various industrial and domestic applications. In this study, a new approach based on a fluorescence ratiometric referencing method was reported to develop an optical dual sensor where platinum (II) meso-tetrakis(pentafluorophenyl)porphyrin (PtTFPP) complex used as the O2-sensitive dye, CdSe/ZnS quantum dots (QDs) combined with phenol red used as the CO2-sensitive dye, and CdSe/ZnS QDs used as the reference dye for the simultaneous detection of O2 and CO2. All the dyes were immobilized in a gas-permeable matrix poly (isobutyl methacrylate) (PolyIBM) and subjected to excitation using a 380 nm LED. The as-obtained distinct fluorescence spectral intensities were alternately exposed to analyte gases to observe changes in the fluorescence intensity. In the presence of O2, the fluorescence intensity of the Pt (II) complex was considerably quenched, while in the presence of CO2, the fluorescence intensity of QDs was increased. The corresponding ratiometric sensitivities of the optical dual sensor for O2 and CO2 were approximately 13 and 144, respectively. In addition, the response and recovery for O2 and CO2 were calculated to be 10 s/35 s and 20 s/60 s, respectively. Thus, a ratiometric optical dual gas sensor for the simultaneous detection of O2 and CO2 was successfully developed. Effects of spurious fluctuations in the intensity of external and excitation sources were suppressed by the ratiometric sensing approach.

scholarly journals Antiresonant Hollow-Core Fiber-Based Dual Gas Sensor for Detection of Methane and Carbon Dioxide in the Near- and Mid-Infrared Regions

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3813 ◽  
Author(s):  
Piotr Jaworski ◽  
Paweł Kozioł ◽  
Karol Krzempek ◽  
Dakun Wu ◽  
Fei Yu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Gas Sensor ◽  
Gas Sensing ◽  
Simultaneous Detection ◽  
Hollow Core ◽  
Mid Infrared ◽  
Sensing Applications ◽  
Core Fiber ◽  
Sensor Configuration ◽  
Carbon Dioxide Co2

In this work, we present for the first time a laser-based dual gas sensor utilizing a silica-based Antiresonant Hollow-Core Fiber (ARHCF) operating in the Near- and Mid-Infrared spectral region. A 1-m-long fiber with an 84-µm diameter air-core was implemented as a low-volume absorption cell in a sensor configuration utilizing the simple and well-known Wavelength Modulation Spectroscopy (WMS) method. The fiber was filled with a mixture of methane (CH4) and carbon dioxide (CO2), and a simultaneous detection of both gases was demonstrated targeting their transitions at 3.334 µm and 1.574 µm, respectively. Due to excellent guidance properties of the fiber and low background noise, the proposed sensor reached a detection limit down to 24 parts-per-billion by volume for CH4 and 144 parts-per-million by volume for CO2. The obtained results confirm the suitability of ARHCF for efficient use in gas sensing applications for over a broad spectral range. Thanks to the demonstrated low loss, such fibers with lengths of over one meter can be used for increasing the laser-gas molecules interaction path, substituting bulk optics-based multipass cells, while delivering required flexibility, compactness, reliability and enhancement in the sensor’s sensitivity.

scholarly journals New approach for gas identification using supervised learning methods (SVM and LVQ)

2019 ◽  
Vol 261 ◽  
pp. 06004
Author(s):  
Aref Harakeh ◽  
Samia Mellah ◽  
Mustapha Ouladsine ◽  
Rafic Younes ◽  
Catherine Bellet
Keyword(s):  
Neural Network ◽  
Carbon Dioxide ◽  
Supervised Learning ◽  
Learning Rate ◽  
Multi Layer Perceptron ◽  
Learning Methods ◽  
New Approach ◽  
Validation Rate ◽  
Gas Identification ◽  
Carbon Dioxide Co2

This article proposes a new approach for gas identification, this approach relies on applying supervised learning methods to identify a single gas as well as a mixture of two gases. The gas is trapped in a gas discharge tube, it is then ionized at a relatively low pressure using an HV transformer. The images captured after the ionization of each single gas is then captured and transformed into a database after being treated in order to be classified. The obtained results were very satisfying for SVM as well as for LVQ. For the case of identification of a single gas, the learning rate as well as the validation rate for both methods were 100%. However, for the case of mixture of two gases, a Multi-Layer Perceptron neural network was used to identify the gases, the learning rate as well as the validation rate were 98.59% and 98.77% respectively. The program developed on MATLAB takes the captured image as an input and outputs the identified gases for the user. The gases used in the experiments are Argon (Ar), oxygen (O2), Helium (He) and carbon dioxide (CO2).

Communication: Photoinduced Carbon Dioxide Binding with Surface-Functionalized Silicon Quantum Dots

2018 ◽  
Author(s):  
Oscar A. Douglas-Gallardo ◽  
Cristián Gabriel Sánchez ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Carbon Dioxide ◽  
Quantum Dots ◽  
Atmospheric Carbon Dioxide ◽  
Density Functional ◽  
Tight Binding ◽  
Carbon Dioxide Concentration ◽  
Research Area ◽  
Silicon Quantum Dots ◽  
Dependent Model ◽  
Photoinduced Charge

<div> <div> <div> <p>Nowadays, the search of efficient methods able to reduce the high atmospheric carbon dioxide concentration has turned into a very dynamic research area. Several environmental problems have been closely associated with the high atmospheric level of this greenhouse gas. Here, a novel system based on the use of surface-functionalized silicon quantum dots (sf -SiQDs) is theoretically proposed as a versatile device to bind carbon dioxide. Within this approach, carbon dioxide trapping is modulated by a photoinduced charge redistribution between the capping molecule and the silicon quantum dots (SiQDs). Chemical and electronic properties of the proposed SiQDs have been studied with Density Functional Theory (DFT) and Density Functional Tight-Binding (DFTB) approach along with a Time-Dependent model based on the DFTB (TD-DFTB) framework. To the best of our knowledge, this is the first report that proposes and explores the potential application of a versatile and friendly device based on the use of sf -SiQDs for photochemically activated carbon dioxide fixation. </p> </div> </div> </div>

PERANCANGAN PROTEKSI KEBAKARAN OTOMATIS PADA KAPAL BERBASIS ARDUINO

2018 ◽  
Vol 1 (2) ◽  
pp. 1-8
Author(s):  
Dody Hidayat
Keyword(s):  
Carbon Dioxide ◽  
Fire Extinguisher ◽  
Carbon Dioxide Co2

Kebakaran dapat terjadi dimana saja salah satunya dapat terjadi di alat transportasi air yakni kapal. Kebakaran selalu menyebabkan hal-hal yang tidak diinginkan baik kerugian material maupun ancaman keselamatan jiwa manusia. Seiring dari kejadian tersebut musibah kecelakaan kapal yang disebabkan oleh bahaya kebakaran sangatlah mungkin terjadi. Salah satu yang dapat mencegah kejadian kebakaran pada kapal haruslah dapat mendeteksi dini kebakaran tersebut. Untuk mendeteksi dini terjadinya kebakaran dikapal maka dirancanglah sebuah alat proteksi kebakaran otomatisberbasis adruino. Dimana Arduino merupakan board yang memiliki sebuah mikrokontroller sebagai  otak kendali sistem. Sistem otomatisasi atau controller tidak akan terlepas dengan apa yang disebut  dengan ‘sensor’. Sensor adalah sebuah alat untuk mendeteksi atau mengukut sesuatu yang digunakan untuk mengubah variasi mekanis, magnetis, panas, sinar dan kimia menjadi tegangan dan arus listrik. sistem yang dirancang ini dilengkapi dengan beberapa sensor diantaranya adalah sensor apiUV-Tron R2868, sensor asap MQ-2 dan kemudian sensor suhuDS18B20. Mikrokontroller sebagai pengendali akan merespon input yang berupa sensor tersebut ketika data yang dibaca oleh sensor mendeteksikebakaran diantaranya mendeteksi adanya asap, kemudian api dan suhu. Sebagai output dari sistem berupa racun api (fire extinguisher)dimana kandungan yang ada pada racun api tersebut berupa Dry Chemical Powder dan Carbon Dioxide (CO2) yang fungsinya digunakan untuk memadamkan api serta dilengkapi buzzer sebagai alarm peringatan jika terjadi kebakaran. 

The Prenatal Development Effects of Carbon Dioxide (CO2) Exposure in Rats (Rattus Norvegicus)

2012 ◽  
Author(s):  
William R. Howard ◽  
Brian Wong ◽  
Michelle Okolica ◽  
Kimberly S. Bynum ◽  
R. A. James
Keyword(s):  
Carbon Dioxide ◽  
Rattus Norvegicus ◽  
Prenatal Development ◽  
Carbon Dioxide Co2

Physiology of Intraluminal Administration of Carbon Dioxide as a Contrast Medium

2020 ◽  
Vol 25 (44) ◽  
pp. 4656-4661 ◽  
Author(s):  
Nikolaos Patelis ◽  
Mikes Doulaptsis ◽  
Stylianos Kykalos ◽  
Eleftherios Spartalis ◽  
Anastasios Maskanakis ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Contrast Agent ◽  
20Th Century ◽  
English Literature ◽  
Human Organism ◽  
Digital Subtraction ◽  
Extensive Search ◽  
Iodinated Contrast ◽  
Iodinated Contrast Agent ◽  
Carbon Dioxide Co2

Background: Carbon dioxide (CO2) exists in nature around us. In the middle of the 20th century, the intraluminal injection of CO2 demonstrated similar results to those of Digital Subtraction Angiography (DSA) with an iodinated contrast agent (ICA). Since then, the technology behind CO2 DSA has developed significantly. Objective: The aim of this study is to inform physicians about the unique properties of CO2 and its physiology after intraluminal injection. Methods: An extensive search for English literature on the properties of CO2 and the physiology of intraluminal administration was conducted using Pubmed. Results: There is sufficient literature on the properties of CO2 and the physiology of CO2 DSA. A review of this literature explains what happens to the human organism after the injection of CO2. Conclusions: There is enough evidence that CO2 DSA is both effective, diagnostic and safe, but the properties of CO2 should be taken under consideration as complications occur, although rarely.

scholarly journals Carbon Dioxide Laser Vulvovaginal Rejuvenation: A Systematic Review

Cosmetics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 56
Author(s):  
Tassahil Messas ◽  
Achraf Messas ◽  
George Kroumpouzos
Keyword(s):  
Carbon Dioxide ◽  
Systematic Review ◽  
Laser Therapy ◽  
Carbon Dioxide Laser ◽  
Invasive Treatment ◽  
Erbium:Yag Laser ◽  
Non Invasive ◽  
Level I ◽  
Carbon Dioxide Co2

Genitourinary syndrome of menopause (GSM) causes significant symptomatic aggravation that affects the quality of life (QoL). Vulvovaginal atrophy (VVA), the hallmark of GSM, is managed with topical non-hormonal therapy, including moisturizers and lubricants, and topical estrogen application. Patients not responding/being unsatisfied with previous local estrogen therapies are candidates for a noninvasive modality. Carbon dioxide (CO2) laser therapy, especially the fractionated type (FrCO2), has drawn considerable attention over the past two decades as a non-invasive treatment for GSM. This systematic review describes the accumulated evidence from 40 FrCO2 laser studies (3466 participants) in GSM/VVA. MEDLINE, Scopus and Cochrane databases were searched through April 2021. We analyze the effects of FrCO2 laser therapy on symptoms, sexual function, and QoL of patients with GSM/VVA. As shown in this review, FrCO2 laser therapy for GSM shows good efficacy and safety. This modality has the potential to advance female sexual wellness. Patient satisfaction was high in the studies included in this systematic review. However, there is a lack of level I evidence, and more randomized sham-controlled trials are required. Furthermore, several clinical questions, such as the number of sessions required that determine cost-effectiveness, should be addressed. Also, whether FrCO2 laser therapy may exert a synergistic effect with systemic and/or local hormonal/non-hormonal treatments, energy-based devices, and other modalities to treat GMS requires further investigation. Lastly, studies are required to compare FrCO2 laser therapy with other energy-based devices such as erbium:YAG laser and radiofrequency.

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