There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

https://www.uta.edu/rfmems/GI_Sensor/papers/ac040049d.pdf

Fiber-Optic Chemical Sensors and Biosensors

Today cross-cutting approaches, where molecular engineering and clever processing are synergistically coupled, allow the chemist to tailor complex hybrid systems of various shapes with perfect mastery at different size scales, composition, functionality, and morphology. Hybrid materials with organic–inorganic or bio–inorganic character represent not only a new field of basic research but also, via their remarkable new properties and multifunctional nature, hybrids offer prospects for many new applications in extremely diverse fields. The description and discussion of the major applications of hybrid inorganic–organic (or biologic) materials are the major topic of this critical review. Indeed, today the very large set of accessible hybrid materials span a wide spectrum of properties which yield the emergence of innovative industrial applications in various domains such as optics, micro-electronics, transportation, health, energy, housing, and the environment among others (526 references).

Applications of advanced hybrid organic–inorganic nanomaterials: from laboratory to market

An increase in world population along with a significant aging portion is forcing rapid rises in healthcare costs. The healthcare system is going through a transformation in which continuous monitoring of inhabitants is possible even without hospitalization. The advancement of sensing technologies, embedded systems, wireless communication technologies, nano technologies, and miniaturization makes it possible to develop smart systems to monitor activities of human beings continuously. Wearable sensors detect abnormal and/or unforeseen situations by monitoring physiological parameters along with other symptoms. Therefore, necessary help can be provided in times of dire need. This paper reviews the latest reported systems on activity monitoring of humans based on wearable sensors and issues to be addressed to tackle the challenges.

Wearable Sensors for Human Activity Monitoring: A Review

Bragg gratings have been fabricated by means of sputtering on the end facet of standard multimode optical fibers towards development of refractometers. Tin oxide was selected as the coating material, and argon and oxygen were used as sputtering gases. Changes on the refractive index of the material were achieved by varying the oxygen percentage in the sputtering gas flow. A reflected peak centered at 586 nm with a full width at half maximum of 70 nm has been obtained, which provides a good structure for the development of wavelength modulated optical fiber sensors. The sensitivity of this structure to the refractive index of the surrounding medium has been studied, obtaining a linear sensitivity of 173 nm/RIU, for refractive index varying from 1.333 to 1.442.

Refractive index sensing performance of a Bragg grating built up on the tip of an optical fiber by reactive sputtering

A new europium(III) luminescent optical fibre sensor based on a tridentate bis(phosphinic amide)phosphine oxide PhPO(C6H4POPhN(CH(CH3)2)2)2 is described. The ligand was successfully immobilized on PVC membrane on optical fibre by dip coating technique. The reaction between europium(III) ion and ligand produced a strong luminescent complex of stoichiometry [1:2], which possessed a maximum emission peak at 612 nm. The sensor luminescence response showed an exponential behavior versus logarithmic concentration of europium(III) ions (10 -8 - 10 -3 M) in aqueous solution with a correlation factor of R 2 = 0.9918, and an acceptable response time (t90-t10) of 92 seconds. This optode is the first luminescent optical fibre sensor for detecting europium(III) ions in water.

/pdf/p1-3-5-europium-iii-ion-detection-in-water-by-a-new-5gksrwh5pm.pdf

P1.3.5 Europium(III) ion detection in water by a new luminescent optical fibre sensor

The Electrostatic Self Assembly Layer-by-Layer (ESA) technique has been already used for the fabrication of optical
fiber pH sensors, the properties of the resultant pH sensitive coatings has been found to be strongly dependent on the
fabrication parameters, especially on the pH of the polyelectrolyte solutions used for the deposition of the coatings. In
this work the resulting properties of the sensitive coatings have been optimized by changing the parameters of
fabrication. Techniques as AFM, for studying the thickness and morphology of the sensing films, and spectroscopy, for
studying the composition of the films, were used for the characterization of the devices. Optical fiber pH sensors with
response from pH 3 to pH 7 were successfully fabricated.

Optical fiber pH sensors based on self-assembled multilayered neutral red coatings

In this work, the characteristics of lossy mode resonances (LMRs) in double-clad fibers where the refractive index (RI) of the second cladding is lower than that of the first cladding are analyzed both numerically and experimentally. In the first place, the LMRs spectra obtained with a 75 nm TiO2 thin film are simulated, and it is observed that a thicker second cladding improves the width of the resonances, making them narrower. Then, two experimental cases (no second cladding, and second cladding with thickness of 1.13 μm) are assessed, showing a good agreement with the previous simulations. Finally, an experimental refractometric study is carried out in liquids (surrounding medium refractive index in the 1.34 - 1.40 range) for both fibers, calculating the full width at 1 dB (FW1dB), the sensitivity, and the figure of merit (FOM). The FW1dB is better for the LMR obtained on the fiber with second cladding while the sensitivity is slightly greater for the fiber without second cladding. In the case of the FOM, it is higher for the double-clad fiber as the narrowing of the resonances outweighs the lower sensitivity. These results show that the performance of LMR-based optical fiber sensors can be improved by employing double-clad fibers.

Improving the Width of Lossy Mode Resonances (LMRs) in Double-Clad Fibers

The application of an etching process in a single-mode multimode single-mode (SMS) fiber allows monitoring the change of refractive index of wind turbine gearbox oil due to temperature and degradation. The SMS was designed for operating at short wavelengths, where the setup is less expensive.

Ignacio R. Matias

Papers

Refractive index sensing performance of a Bragg grating built up on the tip of an optical fiber by reactive sputtering

P1.3.5 Europium(III) ion detection in water by a new luminescent optical fibre sensor

Optical fiber pH sensors based on self-assembled multilayered neutral red coatings

Improving the Width of Lossy Mode Resonances (LMRs) in Double-Clad Fibers

Detection of wind turbine gearbox oil degradation with etched single-mode multimode single-mode (SMS) fiber