scholarly journals Luminescent κ-Carrageenan-Based Electrolytes Containing Neodymium Triflate

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1020 ◽  
Author(s):  
S. Nunes ◽  
S. Saraiva ◽  
R. Pereira ◽  
M. Silva ◽  
L. Carlos ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Alkaline Earth ◽  
Near Infrared ◽  
Low Cost ◽  
Earth Metal ◽  
Cost Effective ◽  
Red Seaweeds ◽  
Multi Wavelength ◽  
Electrochemical Devices ◽  
Uv Visible

In recent years, the synthesis of polymer electrolyte systems derived from biopolymers for the development of sustainable green electrochemical devices has attracted great attention. Here electrolytes based on the red seaweeds-derived polysaccharide κ-carrageenan (κ-Cg) doped with neodymium triflate (NdTrif3) and glycerol (Gly) were obtained by means of a simple, clean, fast, and low-cost procedure. The aim was to produce near-infrared (NIR)-emitting materials with improved thermal and mechanical properties, and enhanced ionic conductivity. Cg has a particular interest, due to the fact that it is a renewable, cost-effective natural polymer and has the ability of gelling in the presence of certain alkali- and alkaline-earth metal cations, being good candidates as host matrices for accommodating guest cations. The as-synthesised κ-Cg-based membranes are semi-crystalline, reveal essentially a homogeneous texture, and exhibit ionic conductivity values 1–2 orders of magnitude higher than those of the κ-Cg matrix. A maximum ionic conductivity was achieved for 50 wt.% Gly/κ-Cg and 20 wt.% NdTrif3/κ-Cg (1.03 × 10−4, 3.03 × 10−4, and 1.69 × 10−4 S cm−1 at 30, 60, and 97 °C, respectively). The NdTrif-based κ-Cg membranes are multi-wavelength emitters from the ultraviolet (UV)/visible to the NIR regions, due to the κ-Cg intrinsic emission and to Nd3+, 4F3/2→4I11/2-9/2.

scholarly journals Light-Emitting-Diode-Based Multispectral Photoacoustic Computed Tomography System

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4861 ◽  
Author(s):  
Sumit Agrawal ◽  
Christopher Fadden ◽  
Ajay Dangi ◽  
Xinyi Yang ◽  
Hussain Albahrani ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Molecular Imaging ◽  
Photoacoustic Imaging ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Tunable Laser ◽  
Cost Effective ◽  
Light Emitting ◽  
Multi Wavelength ◽  
Human Finger

Photoacoustic computed tomography (PACT) has been widely explored for non-ionizing functional and molecular imaging of humans and small animals. In order for light to penetrate deep inside tissue, a bulky and high-cost tunable laser is typically used. Light-emitting diodes (LEDs) have recently emerged as cost-effective and portable alternative illumination sources for photoacoustic imaging. In this study, we have developed a portable, low-cost, five-dimensional (x, y, z, t, λ ) PACT system using multi-wavelength LED excitation to enable similar functional and molecular imaging capabilities as standard tunable lasers. Four LED arrays and a linear ultrasound transducer detector array are housed in a hollow cylindrical geometry that rotates 360 degrees to allow multiple projections through the subject of interest placed inside the cylinder. The structural, functional, and molecular imaging capabilities of the LED–PACT system are validated using various tissue-mimicking phantom studies. The axial, lateral, and elevational resolutions of the system at 2.3 cm depth are estimated as 0.12 mm, 0.3 mm, and 2.1 mm, respectively. Spectrally unmixed photoacoustic contrasts from tubes filled with oxy- and deoxy-hemoglobin, indocyanine green, methylene blue, and melanin molecules demonstrate the multispectral molecular imaging capabilities of the system. Human-finger-mimicking phantoms made of a bone and blood tubes show structural and functional oxygen saturation imaging capabilities. Together, these results demonstrate the potential of the proposed LED-based, low-cost, portable PACT system for pre-clinical and clinical applications.

Transparent graphene electrodes based hybrid perovskites photodetectors with broad spectral response from UV-visible to near-infrared

2021 ◽  
Author(s):  
Guoming Lin ◽  
Yuanwei Lin ◽  
Baoyun Sun
Keyword(s):  
Near Infrared ◽  
Low Cost ◽  
Spectral Response ◽  
Current Ratio ◽  
Daily Lives ◽  
New Class ◽  
Weak Light ◽  
Uv Visible ◽  
Halide Perovskite ◽  
New Applications

Abstract A new class of transparent graphene electrode based organic-inorganic halide perovskite photodetectors with broad spectral response is developed. These ultrasensitive devices exhibit high ON/OFF current ratio, high LDR, broad spectral range, excellent detection for weak light and easy fabrication with low-cost. Their semi-transparent feature and distinct photodetecting function for both sides would provide new applications affecting our daily lives.

scholarly journals A Cost-Effective and Portable Optical Sensor System to Estimate Leaf Nitrogen and Water Contents in Crops

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1449 ◽  
Author(s):  
Mohammad Habibullah ◽  
Mohammad Reza Mohebian ◽  
Raju Soolanayakanahally ◽  
Khan A. Wahid ◽  
Anh Dinh
Keyword(s):  
Water Content ◽  
Near Infrared ◽  
Low Cost ◽  
Gaussian Process Regression ◽  
Cost Effective ◽  
Leaf Nitrogen ◽  
Sensor System ◽  
Coefficient Of Determination ◽  
Healthy Growth ◽  
Water Contents

Non-invasive determination of leaf nitrogen (N) and water contents is essential for ensuring the healthy growth of the plants. However, most of the existing methods to measure them are expensive. In this paper, a low-cost, portable multispectral sensor system is proposed to determine N and water contents in the leaves, non-invasively. Four different species of plants—canola, corn, soybean, and wheat—are used as test plants to investigate the utility of the proposed device. The sensor system comprises two multispectral sensors, visible (VIS) and near-infrared (NIR), detecting reflectance at 12 wavelengths (six from each sensor). Two separate experiments were performed in a controlled greenhouse environment, including N and water experiments. Spectral data were collected from 307 leaves (121 for N and 186 for water experiment), and the rational quadratic Gaussian process regression (GPR) algorithm was applied to correlate the reflectance data with actual N and water content. By performing five-fold cross-validation, the N estimation showed a coefficient of determination ( R 2 ) of 63.91% for canola, 80.05% for corn, 82.29% for soybean, and 63.21% for wheat. For water content estimation, canola showed an R 2 of 18.02%, corn showed an R 2 of 68.41%, soybean showed an R 2 of 46.38%, and wheat showed an R 2 of 64.58%. The result reveals that the proposed low-cost sensor with an appropriate regression model can be used to determine N content. However, further investigation is needed to improve the water estimation results using the proposed device.

Extracting and complexing properties of di-, tri- and tetra ThiaCalix [4] arenes

2016 ◽  
Vol 5 (10) ◽  
pp. 4948
Author(s):  
Amel Ben Othman* ◽  
Imen Ben Fredj ◽  
Rym Abidi
Keyword(s):  
Alkaline Earth ◽  
First Generation ◽  
Earth Metal ◽  
Metal Cations ◽  
Liquid Extraction ◽  
Alkaline Earth Metal ◽  
Coordination Sites ◽  
Liquid Liquid Extraction ◽  
Uv Visible ◽  
Solid Liquid

In the present work, the focus is the study of complexing and extracting properties of three nanoscale derivatives namely multicalixarenes 2C, 3C and 4C which the latter structure is a dendrimer structure of first generation. The metal cations included in this study are the alkali metal, alkaline earth metal, some transition metals, heavy metals and lanthanides. This study was conducted essentially in methanol to determine the stoichiometry of the complexes formed, or the location of the coordination sites, and finally to evaluate selectivity's. These studies have been conducted by UV-visible spectrophotometry, conductivity and proton NMR. The liquid-liquid extraction picrates metal cations followed by UV-visible showed strong selectivity dicalixarenic derived for sodium. The solid liquid extraction of metal picrates followed by 1H-NMR shows an intra- or intermolecular exchange of cations within the calixarene units studied nanocomposites.

Effect of Coupling Indium Tin Oxide with the TiO2–NaYF4:(Gd, Si) Composite for Photocatalytic Properties

2020 ◽  
Vol 20 (12) ◽  
pp. 7629-7635
Author(s):  
Shielah Mavengere ◽  
Sang-Chul Jung ◽  
Jung-Sik Kim
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Near Infrared ◽  
Visible Region ◽  
Impregnation Method ◽  
Solar Simulator ◽  
Visible Spectra ◽  
Multi Wavelength ◽  
Uv Visible ◽  
Ito Nanoparticles

Indium tin oxide (ITO) nanoparticles were coupled with NaYF4:(Gd, Si) using a TiO2-solution impregnation method. Scanning electron microscopy confirmed that TiO2 and ITO nanoparticles were loaded on the surface of the NaYF4:(Gd, Si) upconversion phosphor. The ultraviolet/visible spectra of the 20 wt.% ITO-NaYF4:(Gd, Si)/TiO2 composites were extended at the absorption edges towards the UV-visible region. The 20 wt.% ITO-coupled NaYF4:(Gd, Si)/TiO2 composites exhibited superior photocatalytic efficiency compared to only NaYF4:(Gd, Si)/TiO2 under near-infrared (NIR) irradiation. Multi-wavelength NIR photons of γ > 760 nm from a Xe solar simulator source induced photo-activation through the NaYF4:(Gd, Si) activator centers. The three-cycle photocatalytic reusability performance of the 20 wt.% ITO-impregnated NaYF4:(Gd, Si)/TiO2 composite was positively enhanced by up to 20% more than that of NaYF4:(Gd, Si)/TiO2.

scholarly journals Vein Pattern Locating Technology for Cannulation: A Review of the Low-Cost Vein Finder Prototypes Utilizing near Infrared (NIR) Light to Improve Peripheral Subcutaneous Vein Selection for Phlebotomy

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3573 ◽  
Author(s):  
Cheng-Tang Pan ◽  
Mark D. Francisco ◽  
Chung-Kun Yen ◽  
Shao-Yu Wang ◽  
Yow-Ling Shiue
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Low Cost ◽  
Venous Blood ◽  
Cost Effective ◽  
Medical Laboratory ◽  
Scientific Publications ◽  
Medical Practitioners ◽  
Nir Light ◽  
Number Of Patients

One of the most common means for diagnosis is through medical laboratory testing, which primarily uses venous blood as a sample. This requires an invasive method by cannulation that needs proper vein selection. The use of a vein finder would help the phlebotomist to easily locate the vein, preventing possible pre-analytical error in the specimen collection and even more discomfort and pain to the patient. This paper is a review of the scientific publications on the different developed low-cost vein finder prototypes utilizing camera assisted near infrared (NIR) light technology. Methods: Electronic databases were searched online, these included PubMed (PMC), MEDLINE, Science Direct, ResearchGate, and Institute of Electrical and Electronics Engineers (IEEE) Xplore digital library. Specifically, publications with the terms vein finder prototype, NIR technology, vein detection, and infrared imaging were screened. In addition, reference lists were used to further review related publications. Results: Cannulation challenges medical practitioners because of the different factors that can be reduced by the utilization of a vein finder. A limited number of publications regarding the assessment of personnel performing cannulation were observed. Moreover, variations in methodology, number of patients, type of patients according to their demographics and materials used in the assessment of the developed prototypes were noted. Some studies were limited with regard to the actual human testing of the prototype. Conclusions: The development of a low-cost effective near infrared (NIR) vein finder remains in the phase of improvement. Since, it is being challenged by different human factors, increasing the number of parameters and participants/human for actual testing of the prototypes must also be taken into consideration for possible commercialization. Finally, it was noted that publications regarding the assessment of the performance of phlebotomists using vein finders were limited.

scholarly journals Fabrication and Characterization of Near Infrared Molybdenum Disulfide/Silicon Heterojunction Photodetector by Drop Casting Method

2021 ◽  
Author(s):  
Haroon Rashid ◽  
Norhana Arsad ◽  
Harith Ahmad ◽  
Ahmad Ashrif A. Bakar ◽  
Mamun Ibne Reaz
Keyword(s):  
Molybdenum Disulfide ◽  
Near Infrared ◽  
Film Growth ◽  
Low Cost ◽  
Incident Light ◽  
Cost Effective ◽  
Optoelectronic Device ◽  
Casting Method ◽  
Incident Laser Power ◽  
Device Applications

In this work, a highly efficient, molybdenum disulfide (MoS2) based near infrared (NIR) heterojunction photodetector is fabricated on a Si substrate using a cost-effective and simple drop casting method. A non-stoichiometric and inhomogeneous MoS2 layer with a S/Mo ratio of 2.02 is detected using energy dispersive X-ray spectroscopy and field emission scanning electron microscope analysis. Raman shifts are noticed at 382.42 cm-1 and 407.97 cm-1, validating MoS2 thin film growth with a direct bandgap of 2.01 eV. The fabricated n-MoS2/p-Si photodetector is illuminated with a 785 nm laser at different intensities, and demonstrate the ability of the photodetector to work in both regions, the forward biased and reverse biased from above 1.5 V and less than -1.0 V. The highest responsivity, R is calculated to be 0.52 A/W while the detectivity D* is 4.08 x 10^10 Jones for an incident light intensity of 9.57 mW/cm2. The minimum rise and fall times are calculated as 1.77 ms and 1.31 ms for an incident laser power of 9.57 mW/cm^2 and 6.99 mW/cm^2 respectively at a direct current bias voltage of 10 V. The demonstrated results are promising for the low-cost fabrication of a thin MoS2 film for photonics and optoelectronic device applications.

scholarly journals Low cost infrared and near infrared sensors for UAVs

2014 ◽  
Vol XL-1 ◽  
pp. 1-7 ◽  
Author(s):  
S. T. Aden ◽  
J. P. Bialas ◽  
Z. Champion ◽  
E. Levin ◽  
J. L. McCarty
Keyword(s):  
Remote Sensing ◽  
Near Infrared ◽  
Low Cost ◽  
Cost Effective ◽  
Infrared Sensors ◽  
Management Options ◽  
Time Saving ◽  
Wide Range ◽  
Infrared Cameras ◽  
Wildland Firefighting

Thermal remote sensing has a wide range of applications, though the extent of its use is inhibited by cost. Robotic and computer components are now widely available to consumers on a scale that makes thermal data a readily accessible resource. In this project, thermal imagery collected via a lightweight remote sensing Unmanned Aerial Vehicle (UAV) was used to create a surface temperature map for the purpose of providing wildland firefighting crews with a cost-effective and time-saving resource. The UAV system proved to be flexible, allowing for customized sensor packages to be designed that could include visible or infrared cameras, GPS, temperature sensors, and rangefinders, in addition to many data management options. Altogether, such a UAV system could be used to rapidly collect thermal and aerial data, with a geographic accuracy of less than one meter.

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