scholarly journals A New Diffuse Optics Emitter for High Visual Diffuse Transmission Density Measurement

2019 ◽  
Vol 9 (14) ◽  
pp. 2774 ◽  
Author(s):  
Zilong Liu ◽  
Yuxiao Li ◽  
Yiqin Jiang ◽  
Jin Li ◽  
Ruping Liu ◽  
...  

In visual diffuse transmission density measurement, it is hard to measure optical density (OD) up to 6.0 because the signal to noise is more than 10E-06. Thus, there are only two methods to find the measurement. One is using a highly sensitive detector with low background noise, and the other is improving the incident light flux with a wide spectrum, including visual scope. A new diffuse optics emitter was designed to realize OD measurements up to 6.0. It uses 235 optical fibers on a hemisphere to collect and feed in the incident flux, then emits this flux by a diffuse opal. Thus, an incident light with a high diffuse coefficient and high incident flux was realized for high OD measurement. This emitter has been used in the new national reference of National Institute of Metrology, China (NIM) for diffuse transmission optical density. According to the measurement result in this reference, the OD can be measured up to 6.6.

2016 ◽  
Vol 16 (4) ◽  
pp. 197-200
Author(s):  
E.N. Eskina ◽  
◽  
E.A. Egorov ◽  
A.V. Belogurova ◽  
А.А. Gvetadze ◽  
...  

Author(s):  
Oladotun A. Ojo ◽  
Peter A. Oluwafisoye ◽  
Charles O. Chime

The sensitivity of radiographic films is an important factor to the clarity and accuracy of X-ray exposure to patients during treatment or diagnostic periods. It is therefore important to do a thorough analysis of the sensitivity of the radiographic film before and after exposure to enhance the Quality Assurance (QA) and the Quality Control (QC), of the exposure procedures. The optical densities (OD) of each film was measured, with a densitometer model MA 5336, made by GAMMEX. These values were then converted to the absorbed dose (X mGy), which is the amount of dose absorbed by each patient. The optical density versus the dose curve, followed the expected pattern, showing a good prediction from the General model, that the films employed in the exposures were of good quality and standard. Hence the optical density versus dose sensitometric curves depicts the outcome of the various films sensitivity after an exposure to the X-ray radiation through the patients.


The Analyst ◽  
2020 ◽  
Vol 145 (15) ◽  
pp. 5307-5313
Author(s):  
Huan Lin ◽  
Xin Cheng ◽  
Ming-Jie Yin ◽  
Zhouzhou Bao ◽  
Xunbin Wei ◽  
...  

A flexible porphyrin doped polymer optical fiber was developed for fast and highly sensitive monitoring of DNT vapors.


2020 ◽  
Vol 66 (3) ◽  
pp. 256-262 ◽  
Author(s):  
Sarah Martinez ◽  
Eric Déziel

Optical density (OD) measurement is the standard method used in microbiology for estimating bacterial concentrations in cultures. However, most studies do not compare these measurements with viable cell counts and assume that they reflect the real cell concentration. Burkholderia thailandensis was recently identified as a polyhydroxyalkanoate (PHA) producer. PHA biosynthesis seems to be coded by an orthologue of the Cupriavidus necator phaC gene. When growing cultures of wild-type strain E264 and an isogenic phaC mutant, we noted a difference in their OD600 values, although viable cell counts indicated similar growth. Investigating the cellular morphologies of both strains, we found that under our conditions the wild-type strain was full of PHA granules, deforming the cells, while the mutant contained no granules. These factors apparently affected the light scattering, making the OD600 values no longer representative of cell density. We show a direct correlation between OD600 values and the accumulation of PHA. We conclude that OD measurement is unreliable for growth evaluation of B. thailandensis because of PHA production. This study also suggests that B. thailandensis could represent an excellent candidate for PHA bioproduction. Correlation between OD measurements and viable cell counts should be verified in any study performed with B. thailandensis.


Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5246 ◽  
Author(s):  
Pesavento ◽  
Profumo ◽  
Merli ◽  
Cucca ◽  
Zeni ◽  
...  

Highly sensitive plasmonic optical fiber platforms combined with receptors have been recently used to obtain selective sensors. A low-cost configuration can be obtained exploiting a D-shaped plastic optical fiber covered with a multilayer sensing surface. The multilayer consists of a gold film, functionalized with a specific receptor, where the surface plasmon resonance (SPR) occurs. The signal is produced by the refractive index variation occurring as a consequence of the receptor-to analyte binding. In this work, a selective sensor for copper(II) detection in drinking water, exploiting a self-assembled monolayer (SAM) of d,l-penicillamine as the sensing layer, has been developed and tested. Different concentrations of copper(II) in NaCl 0.1 M solutions at different pH values and in a real matrix (drinking water) have been considered. The results show that the sensor is able to sense copper(II) at concentrations ranging from 4 × 10-6 M to 2 × 10-4 M. The use of this optical chemical sensor is a very attractive perspective for fast, in situ and low-cost detection of Cu(II) in drinking water for human health concerns. Furthermore, the possibility of remote control is feasible as well, because optical fibers are employed.


2003 ◽  
Vol 7 (1) ◽  
pp. 122-128 ◽  
Author(s):  
J.ürg M Sommer ◽  
Peter H Smith ◽  
Sumathy Parthasarathy ◽  
Jesse Isaacs ◽  
Sharmila Vijay ◽  
...  

1987 ◽  
Vol 26 (16) ◽  
pp. 3249 ◽  
Author(s):  
A. W. M. Smeulders ◽  
T. K. ten Kate

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