Remote, Long-Pathlength Cell for High-Sensitivity Raman Spectroscopy

1987 ◽  
Vol 41 (1) ◽  
pp. 126-130 ◽  
Author(s):  
Scott D. Schwab ◽  
Richard L. McCreery
Keyword(s):  
Fiber Optics ◽  
Laser Light ◽  
Capillary Tube ◽  
High Sensitivity ◽  
Sample Tube ◽  
Increased Sensitivity ◽  
Sampling Systems ◽  
Power Densities ◽  
Objective Being ◽  
Focused Beam

Fiber optics were used to interface a Raman spectrometer to a long (1 m) sample tube, with the objective being increased sensitivity. Internal reflection of the laser light and the Raman scatter within the sample tube permitted a long solution length to be sampled, increasing the Raman sensitivity by factors of 30–50 over conventional capillary tube sampling systems. In addition, the sample was subjected to much lower power densities than with systems employing a focused beam, thus minimizing radiation damage. Detection limits of 10−9 to 10−8 M were achieved for resonance Raman scatterers, and normal Raman scatterers could be detected at the 1 × 10−5 M level.

scholarly journals Analysis of Curvature in Fiber Optic Cable for Macrobending-Based Slope Sensor

2021 ◽  
Vol 3 (1) ◽  
pp. 45-56
Author(s):  
Imam Mulyanto
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Laser Light ◽  
Laser Intensity ◽  
Single Mode ◽  
Power Losses ◽  
Fiber Optic Cable ◽  
Power Meter ◽  
Working Principle

The analysis of fiber optics for macro bending-based slope sensors using SMF-28 single-mode optical fibers has been successfully conducted. Fiber optics were treated to silicon rubber molding and connected with laser light and power meters to measure the intensity of laser power generated. The working principle was carried out using the macrobending phenomenon on single-mode optical fibers. The intensity of laser light in fiber optic cables decreases in the event of indentation or bending of the fiber optic cable. Power losses resulting from the macrobending process can be seen in the result of the information sensitivity of fiber optics to the change of angle given. From the results of the study, the resulting fiber optic sensitivity value is -0.1534o/dBm. The larger the angle given, the lower the laser intensity received by the power meter.

scholarly journals 2D Propagation Simulation of Variation Parameters of U-shape Fiber Optic

2020 ◽  
Vol 10 (2) ◽  
pp. 153-158
Keyword(s):  
Fiber Optics ◽  
Power Flow ◽  
Fiber Optic ◽  
Power Transmission ◽  
Simulation Analysis ◽  
Reducing Power ◽  
High Sensitivity ◽  
Curvature Radius ◽  
Sensor Applications ◽  
Core Fiber

Fiber optic has extraordinary properties and is suitable in sensor applications due to its special potential. Currently, macro bending characteristics of newly developed hetero core fiber optic element are designed and evaluated. This paper presents the preliminary results obtained from the numerical simulation analysis of the bending sensitivity of U-shape fiber optics toward the 2D electromagnetic wave in terms of mesh, curvature radius, core fiber size, and turn number. Fiber optics with core sizes of 4, 9, 50, and 62.5 μm were designed. In addition, the combination of core diameters 50-4-50, 50-9-50, 62.5-4-62.5, and 62.5-9-62.5 μm is evaluated to compare the outcome of transmission power in terms of hetero core structure of fiber optic. Simulation is performed using COMSOL Multiphysics simulation tool. The developed U-shape fiber optic is designed to sense the distortion of reducing power transmission by comparing input and output power. Results show that the selected mesh depends on the size of geometry bending fiber optics, and fine and finer mesh is the best for U-shape fiber optic. Furthermore, the power flow on the fiber decreases with the decreasing curvature radius and increasing turn number. The fiber with a core size combination of 62.5–4–62.5 um has high sensitivity in terms of loss. The attained results possess higher potential in the field of sensor applications, such as displacement, strain, pressure, and monitoring respiration, on human body. This study serves as a basis for further investigation of nanomaterial coating on fiber optics, thereby enhancing its credibility for sensing.

scholarly journals Trypanosome infections in naturally infected horses and donkeys of three active sleeping sickness foci in the south of Chad

2020 ◽  
Author(s):  
Joël Vourchakbé ◽  
Arnol Auvaker Tiofack ◽  
Mbida Mpoame ◽  
Gustave Simo
Keyword(s):  
Capillary Tube ◽  
Control Strategies ◽  
Clinical Signs ◽  
Sleeping Sickness ◽  
Diagnostic Methods ◽  
Trypanosome Species ◽  
Blood Samples ◽  
Potential Reservoir ◽  
Objective Being

Abstract Background Equine trypanosomiases are complex infectious diseases with overlapping clinical signs defined by their mode of transmission. Despite their economic impacts, these diseases have been neglected by the scientific community, the veterinary authorities and regulatory organizations. To fill the observed knowledge gap, we undertook the identification of different trypanosome species and subspecies naturally infecting horses and donkeys within the Chadian sleeping sickness focus. The end objective, being to investigate the potential role of these domestic animals as reservoirs of the human infective Trypanosoma brucei gambienseMethod Blood samples were collected from 155 donkeys and 131 horses in three human African trypanosomiasis (HAT) foci of Chad. Rapid diagnostic test (RDT) and capillary tube centrifugation (CTC) test were used to search for trypanosome infections. DNA was extracted from each blood sample and different trypanosome species and subspecies were identified with molecular tools.Results From 286 blood samples collected, 54 (18.9%) and 36 (12.6%) were respectively positive for RDT and CTC. PCR revealed 144 (50.3%) animals with trypanosome infections. The kappa Cohen coefficients used to evaluate the concordance between the diagnostic methods were low; ranging from 0.087±0.0473 to 0.48 ± 0.0698. Trypanosomes of the subgenus Trypanozoon were the most prevalent (29.4%), followed by T. congolense forest (11.5%), T. congolense savannah (4.9%) and T. vivax (4.5%). Two donkeys and one horse from the Maro HAT focus were found with T. b. gambiense infections. Between animal species and HAT foci, no significant differences were observed in the infection rates of different trypanosomes. Conclusion This study revealed several trypanosome species and sub species in donkeys and horses, highlighting the existence of AAT in HAT foci of Chad. The identification of T. b. gambiense in donkeys and horses suggests considering these animals as potential reservoir for HAT in Chad. The presence of both human-infective and human non infective trypanosomes species highlights the need for developing joined control strategies for HAT and AAT.

High-sensitivity temperature sensor based on ultraviolet glue-filled silica capillary tube

2020 ◽  
Vol 67 (16) ◽  
pp. 1327-1333
Author(s):  
Bowen Li ◽  
Yinggang Liu ◽  
Xiaoya Song ◽  
Haiwei Fu ◽  
Zhenan Jia ◽  
...  
Keyword(s):  
Temperature Sensor ◽  
Capillary Tube ◽  
High Sensitivity ◽  
Silica Capillary

scholarly journals A Mutation in the Follicle-Stimulating Hormone Receptor as a Cause of Familial Spontaneous Ovarian Hyperstimulation Syndrome

2004 ◽  
Vol 89 (4) ◽  
pp. 1255-1258 ◽  
Author(s):  
Lucia Montanelli ◽  
Anne Delbaere ◽  
Costantino Di Carlo ◽  
Carmine Nappi ◽  
Guillaume Smits ◽  
...  
Keyword(s):  
In Vitro Fertilization ◽  
Ovarian Hyperstimulation Syndrome ◽  
Follicle Stimulating Hormone ◽  
High Sensitivity ◽  
Ovarian Hyperstimulation ◽  
Satisfactory Explanation ◽  
Vitro Fertilization ◽  
Increased Sensitivity ◽  
Stimulation Of

Abstract Ovarian hyperstimulation syndrome (OHSS) occurs mainly after excessive stimulation of the ovaries by exogenous gonadotropins administrated in the context of in vitro fertilization procedures (iatrogenic OHSS). Recently, spontaneous and recurrent occurrence of the disease (spontaneous OHSS) was shown in two families to be caused by mutations affecting the follitropin receptor (FSHr). The two mutant FSHr (T449I, D567N) harbor aminoacid substitutions in the serpentine portion of the receptor and display abnormally high sensitivity to the pregnancy hormone hCG, thus providing a satisfactory explanation to the phenotype. In addition, mutant D567N showed also increased sensitivity to thyrotopin (TSH) and displayed increase in basal (ligand-independent) activity. In this report, we describe a new familial case of recurrent OHSS. The affected women were heterozygous for a different mutation involving codon 449, where an alanine was substituted for threonine. Similar to D567N, the T449A FSHr mutant shows an increase of its sensitivity to both hCG and TSH, together with an increase in basal activity. Together with the two previous studies, this report shows that inappropriate stimulation of the FSHr by hCG is a cause of spontaneous OHSS.

Use Of A Capillary X-Ray Focused Beam To Investigate The Chemical Composition Of CdZnTe Wafers With High Resolution CdZnTe Detectors

1997 ◽  
Vol 487 ◽  
Author(s):  
P. Fougères ◽  
Ch. Burggraf ◽  
Chr. Burggraf ◽  
J. M. Koebel ◽  
C. Koenig ◽  
...  
Keyword(s):  
High Resolution ◽  
High Sensitivity ◽  
X Rays ◽  
Position Resolution ◽  
X Ray ◽  
High Position ◽  
Cdznte Detector ◽  
Cdznte Detectors ◽  
Focused Beam ◽  
New System

AbstractThe control of the concentration of Zn and its fluctuation in the high pressure Bridgman grown CdZnTe crystals is part of our characterization work on the ternary grown ingots grown in house. In order to reach both high sensitivity and high position resolution, we have developed a new system consisting of a X-ray generator, coupled to a focusing X-ray capillary, delivering intense beams in the micron scale, since the intensity gain is around a factor of 100 compared to conventional methods.The characteristic X-rays are measured through a high resolution CdZnTe detector (225 eV at 5.9 keV FWHM) cooled by a Peltier system. The results of our investigations on different kinds of crystals will be discussed.

scholarly journals Sensitivity Enhancement of Heterocore Macrobend Fiber Optics by Adding a ZnO Film

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Noor Azie Azura Mohd Arif ◽  
Dilla Duryha Berhanuddin ◽  
Abang Annuar Ehsan
Keyword(s):  
Refractive Index ◽  
Fiber Optics ◽  
Optical Fibers ◽  
High Sensitivity ◽  
Comsol Multiphysics ◽  
Zno Films ◽  
Curvature Radius ◽  
Optimum Thickness ◽  
Zno Film ◽  
The Relationship

Optical fibers with high sensitivity are in demand due to their great potential in sensor application. Semiconductors, such as ZnO, are good materials. Using them as a second cladding offers opportunities in realizing next-generation multimaterial fiber optics. COMSOL Multiphysics is used to simulate heterocore macrobend fiber optics with the same curvature radius but different values of refractive index and thickness of ZnO films. The optimum thickness of ZnO films is identified by determining the loss of optical fibers. Macrobend heterocore fiber optics by adding ZnO thin film has been established by simulating and interpreting the relationship in terms of transmission and refractive index in the evanescent field. These results will provide a reliable fundamental to guide the performance in practice.

High-quality RNA improves sensitivity of SARS-CoV-2 detection by colorimetric RT-LAMP

2021 ◽  
pp. 153537022110547
Author(s):  
Marta Puigmulé ◽  
Mònica Coll ◽  
Alexandra Pérez-Serra ◽  
Laura López ◽  
Ferran Picó ◽  
...  
Keyword(s):  
Diagnostic Test ◽  
Quantitative Pcr ◽  
Standard Method ◽  
Reverse Transcription ◽  
Gold Standard ◽  
High Sensitivity ◽  
High Quality ◽  
Gold Standard Method ◽  
Increased Sensitivity ◽  
User Friendly

The global SARS-CoV-2 pandemic requires a rapid, reliable, and user-friendly diagnostic test to help control the spread of the virus. Reverse transcription and quantitative PCR (RT-qPCR) is currently the gold standard method for SARS-CoV-2 detection. Here, we develop a protocol based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) and demonstrate increased sensitivity of this technique using fresh RNA extracts compared to RNA samples subjected to freezing/thawing cycles. We further compare RT-LAMP to RT-qPCR and demonstrate that the RT-LAMP approach has high sensitivity in fresh RNA extracts and can detect positive samples with Ct values between 8 and 35.

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