scholarly journals Synergy between NIR luminescence and thermal emission toward highly sensitive NIR operating emissive thermometry

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lukasz Marciniak ◽  
Karolina Trejgis ◽  
Radosław Lisiecki ◽  
Artur Bednarkiewicz
Keyword(s):  
Thermal Emission ◽  
Thermal Sensitivity ◽  
Relative Sensitivity ◽  
Black Body ◽  
Temperature Dependent ◽  
Host Matrix ◽  
Practical Applications ◽  
Highly Sensitive ◽  
New Type ◽  
Nir Luminescence

AbstractThere are many figures of merit, which determine suitability of luminescent thermometers for practical applications. These include thermal sensitivity, thermal accuracy as well as ease and cost effectivness of technical implementation. A novel contactless emission thermometer is proposed, which takes advantage of the coexistence of photoluminescence from Nd3+ doping ions and black body emission in transparent Nd3+ doped-oxyfluorotellurite glass host matrix. The opposite temperature dependent emission from these two phenomena, enables to achieve exceptionally high relative sensitivity SR = 8.2%/°C at 220 °C. This enables to develop new type of emissive noncontact temperature sensors.

scholarly journals One ion to catch them all: Targeted high-precision Boltzmann thermometry over a wide temperature range with Gd3+

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Dechao Yu ◽  
Huaiyong Li ◽  
Dawei Zhang ◽  
Qinyuan Zhang ◽  
Andries Meijerink ◽  
...  
Keyword(s):  
Wide Temperature Range ◽  
Thermal Sensitivity ◽  
Energy Levels ◽  
Relative Sensitivity ◽  
Black Body ◽  
Temperature Sensing ◽  
Lanthanide Ions ◽  
Visible Range ◽  
Temperature Range ◽  
Luminescence Thermometry

AbstractRatiometric luminescence thermometry with trivalent lanthanide ions and their 4fn energy levels is an emerging technique for non-invasive remote temperature sensing with high spatial and temporal resolution. Conventional ratiometric luminescence thermometry often relies on thermal coupling between two closely lying energy levels governed by Boltzmann’s law. Despite its simplicity, Boltzmann thermometry with two excited levels allows precise temperature sensing, but only within a limited temperature range. While low temperatures slow down the nonradiative transitions required to generate a measurable population in the higher excitation level, temperatures that are too high favour equalized populations of the two excited levels, at the expense of low relative thermal sensitivity. In this work, we extend the concept of Boltzmann thermometry to more than two excited levels and provide quantitative guidelines that link the choice of energy gaps between multiple excited states to the performance in different temperature windows. By this approach, it is possible to retain the high relative sensitivity and precision of the temperature measurement over a wide temperature range within the same system. We demonstrate this concept using YAl3(BO3)4 (YAB):Pr3+, Gd3+ with an excited 6PJ crystal field and spin-orbit split levels of Gd3+ in the UV range to avoid a thermal black body background even at the highest temperatures. This phosphor is easily excitable with inexpensive and powerful blue LEDs at 450 nm. Zero-background luminescence thermometry is realized by using blue-to-UV energy transfer upconversion with the Pr3+−Gd3+ couple upon excitation in the visible range. This method allows us to cover a temperature window between 30 and 800 K.

Near infrared absorbing near infrared emitting highly-sensitive luminescent nanothermometer based on Nd3+ to Yb3+ energy transfer

2015 ◽  
Vol 17 (37) ◽  
pp. 24315-24321 ◽  
Author(s):  
Ł. Marciniak ◽  
A. Bednarkiewicz ◽  
M. Stefanski ◽  
R. Tomala ◽  
D. Hreniak ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Near Infrared ◽  
Temperature Dependent ◽  
Highly Sensitive ◽  
New Type ◽  
Physical Background

A new type of near infrared absorbing near infrared emitting (NANE) luminescent nanothermometer is presented, whose physical background relies on efficient and temperature dependent Nd3+ to Yb3+ energy transfer under 808 nm photo-excitation.

A new generation of highly sensitive luminescent thermometers operating in the optical window of biological tissues

2016 ◽  
Vol 4 (24) ◽  
pp. 5559-5563 ◽  
Author(s):  
Lukasz Marciniak ◽  
Artur Bednarkiewicz ◽  
Diana Kowalska ◽  
Wieslaw Strek
Keyword(s):  
High Sensitivity ◽  
Biological Tissues ◽  
Temperature Dependent ◽  
Optical Window ◽  
Highly Sensitive ◽  
New Type ◽  
New Generation ◽  
First Time

A new type of luminescent thermometer based on highly temperature dependent d–d Cr3+ transitions related to barely temperature dependent f–f Nd3+ transitions for bio-application is reported for the first time, showing exceptionally high sensitivity.

scholarly journals Recent Advances in Quenchbody, a Fluorescent Immunosensor

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1223
Author(s):  
Jinhua Dong ◽  
Hiroshi Ueda
Keyword(s):  
Fluorescence Intensity ◽  
Fluorescent Dyes ◽  
Antibody Fragment ◽  
Disease Diagnosis ◽  
Disease Biomarkers ◽  
Highly Sensitive ◽  
Physiologically Active Substances ◽  
New Type ◽  
Antigen Antibody ◽  
Active Substances

The detection of viruses, disease biomarkers, physiologically active substances, drugs, and chemicals is of great significance in many areas of our lives. Immunodetection technology is based on the specificity and affinity of antigen–antibody reactions. Compared with other analytical methods such as liquid chromatography coupled with mass spectrometry, which requires a large and expensive instrument, immunodetection has the advantages of simplicity and good selectivity and is thus widely used in disease diagnosis and food/environmental monitoring. Quenchbody (Q-body), a new type of fluorescent immunosensor, is an antibody fragment labeled with fluorescent dyes. When the Q-body binds to its antigen, the fluorescence intensity increases. The detection of antigens by changes in fluorescence intensity is simple, easy to operate, and highly sensitive. This review comprehensively discusses the principle, construction, application, and current progress related to Q-bodies.

scholarly journals Gold and ZnO-Based Metal-Semiconductor Network for Highly Sensitive Room-Temperature Gas Sensing

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3815
Author(s):  
Renyun Zhang ◽  
Magnus Hummelgård ◽  
Joel Ljunggren ◽  
Håkan Olin
Keyword(s):  
Solar Cells ◽  
Gas Sensor ◽  
Network Structure ◽  
Room Temperature ◽  
Gas Sensing ◽  
Zno Nanowires ◽  
Gold Particles ◽  
Highly Sensitive ◽  
Semiconductor Electronics ◽  
New Type

Metal-semiconductor junctions and interfaces have been studied for many years due to their importance in applications such as semiconductor electronics and solar cells. However, semiconductor-metal networks are less studied because there is a lack of effective methods to fabricate such structures. Here, we report a novel Au–ZnO-based metal-semiconductor (M-S)n network in which ZnO nanowires were grown horizontally on gold particles and extended to reach the neighboring particles, forming an (M-S)n network. The (M-S)n network was further used as a gas sensor for sensing ethanol and acetone gases. The results show that the (M-S)n network is sensitive to ethanol (28.1 ppm) and acetone (22.3 ppm) gases and has the capacity to recognize the two gases based on differences in the saturation time. This study provides a method for producing a new type of metal-semiconductor network structure and demonstrates its application in gas sensing.

Study on Water Cushion Belt Conveyor

2014 ◽  
Vol 1016 ◽  
pp. 14-18
Author(s):  
Xian Wei Liu ◽  
Jia Sheng Wang ◽  
Lan Tao Wu ◽  
Xin Zhang ◽  
Hua Cheng
Keyword(s):  
Reynolds Equation ◽  
Belt Conveyor ◽  
Working Mechanism ◽  
Film Properties ◽  
Practical Applications ◽  
Lubrication Equation ◽  
Start Up ◽  
New Type ◽  
Air Cushion ◽  
Lubricating Mechanism

Based on air cushion belt conveyor, a new type of belt conveyor named water cushion belt conveyor is proposed. It has a wide scope of applications for its features such as stability and reliability, capability of full load start-up, and environment-friendliness. This paper studies the working mechanism and lubricating mechanism of the water cushion belt conveyor. The basic lubrication equation of the water cushion is deduced from the universal form of the Reynolds equation used to study the pressure film properties of the water cushion. The design of the key part of the water cushion device is described in details. The research can be taken as a reference in practical applications.

Optimization of Model Training Based on Iterative Minimum Covariance Determinant In Motor-Imagery BCI

2021 ◽  
pp. 2150030
Author(s):  
Jing Jin ◽  
Hua Fang ◽  
Ian Daly ◽  
Ruocheng Xiao ◽  
Yangyang Miao ◽  
...  
Keyword(s):  
Motor Imagery ◽  
Classification Performance ◽  
Minimum Covariance Determinant ◽  
Fisher Score ◽  
Practical Applications ◽  
Computer Interfaces ◽  
Highly Sensitive ◽  
Feature Optimization ◽  
The Common ◽  
Model Training

The common spatial patterns (CSP) algorithm is one of the most frequently used and effective spatial filtering methods for extracting relevant features for use in motor imagery brain–computer interfaces (MI-BCIs). However, the inherent defect of the traditional CSP algorithm is that it is highly sensitive to potential outliers, which adversely affects its performance in practical applications. In this work, we propose a novel feature optimization and outlier detection method for the CSP algorithm. Specifically, we use the minimum covariance determinant (MCD) to detect and remove outliers in the dataset, then we use the Fisher score to evaluate and select features. In addition, in order to prevent the emergence of new outliers, we propose an iterative minimum covariance determinant (IMCD) algorithm. We evaluate our proposed algorithm in terms of iteration times, classification accuracy and feature distribution using two BCI competition datasets. The experimental results show that the average classification performance of our proposed method is 12% and 22.9% higher than that of the traditional CSP method in two datasets ([Formula: see text]), and our proposed method obtains better performance in comparison with other competing methods. The results show that our method improves the performance of MI-BCI systems.

scholarly journals A Highly Sensitive, Polarization Maintaining Photonic Crystal Fiber Sensor Operating in the THz Regime

Photonics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 40 ◽  
Author(s):  
Sohel Rana ◽  
Nirmala Kandadai ◽  
Harish Subbaraman
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
High Sensitivity ◽  
Relative Sensitivity ◽  
Computational Technique ◽  
The Finite Element Method ◽  
High Birefringence ◽  
Crystal Fiber ◽  
Highly Sensitive ◽  
Imaging And Spectroscopy

In this paper, a high sensitivity, polarization preserving photonic crystal fiber (PCF), based on circular air holes for sensing in the terahertz (THz) band, is presented. The finite element method, a practical and precise computational technique for describing the interactions between light and matter, is used to compute the modal properties of the designed fiber. For the designed PCF, comprising of circular air holes in both the cladding and in the porous core, a relative sensitivity of 73.5% and a high birefringence of 0.013 are achieved at 1.6 THz. The all circular air-hole structure, owing to its simplicity and compatibility with the current fiber draw technique for PCF fabrication, can be realized practically. It is anticipated that the designed fiber can be employed in applications such as detection of biological samples and toxic chemicals, imaging, and spectroscopy.

scholarly journals Packaged Droplet Microresonator for Thermal Sensing with High Sensitivity

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3881 ◽  
Author(s):  
Xiaogang Chen ◽  
Liang Fu ◽  
Qijing Lu ◽  
Xiang Wu ◽  
Shusen Xie
Keyword(s):  
Liquid Droplet ◽  
Thermal Sensitivity ◽  
High Sensitivity ◽  
Liquid Limit ◽  
Practical Applications ◽  
Sensing Applications ◽  
Cavity Structure ◽  
Thermal Sensing ◽  
Facile Fabrication ◽  
Definition Of

Liquid droplet and quasi-droplet whispering gallery mode (WGM) microcavities have been widely studied recently for the enhanced spatial overlap between the liquid and WGM field, especially in sensing applications. However, the fragile cavity structure and the evaporation of liquid limit its practical applications. Here, stable, packaged, quasi-droplet and droplet microcavities are proposed and fabricated for thermal sensing with high sensitivity. The sensitivity and electromagnetic field intensity distribution are analyzed by Mie theory, and a quantified definition of the quasi-droplet is presented for the first time to the best of our knowledge. By doping dye material directly into the liquid, lasing packaged droplet and quasi-droplet microcavity sensors with a high thermal sensitivity of up to 205.3 pm/°C are experimentally demonstrated. The high sensitivity, facile fabrication, and mechanically robust properties of the optofluidic, packaged droplet microresonator make it a promising candidate for future integrated photonic devices.

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