scholarly journals Optical Fibres for Distributed Corrosion Sensing - Architecture and Characterisation

2013 ◽  
Vol 558 ◽  
pp. 522-533 ◽  
Author(s):  
Roman Kostecki ◽  
Heike Ebendorff-Heidepriem ◽  
Stephen C. Warren-Smith ◽  
Grant McAdam ◽  
Claire Davis ◽  
...  
Keyword(s):  
Silica Glass ◽  
Harsh Environments ◽  
Optical Fibres ◽  
Transmission Properties ◽  
Service Environments ◽  
The Stability ◽  
Microstructured Optical Fibres ◽  
And Storage ◽  
Better Than

This paper summarises recent work conducted on the development of exposed core microstructured optical fibres for distributed corrosion sensing. Most recently, exposed-core fibres have been fabricated in silica glass, which is known to be reliable under a range of processing and service environments. We characterise the stability of these new silica fibres when exposed to some typical sensing and storage environments. We show the background loss to be the best achieved to date for exposed-core fibres, while the transmission properties are up to ~2 orders of magnitude better than for the previously reported exposed-core fibres produced in soft glass. This provides a more robust fibre platform for corrosion sensing conditions and opens up new opportunities for distributed optical fibre sensors requiring long-term application in harsh environments.

scholarly journals Parabolic Pulse Generation Using Tapered Microstructured Optical Fibres

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
Natasha Vukovic ◽  
Neil G. R. Broderick ◽  
Francesco Poletti
Keyword(s):  
Pulse Shape ◽  
Pulse Shaping ◽  
Numerical Study ◽  
Pulse Generation ◽  
Optical Fibres ◽  
Step Index ◽  
Index Fibre ◽  
Microstructured Optical Fibres ◽  
Misfit Parameter ◽  
Better Than

This paper presents a numerical study of parabolic pulse generation in tapered microstructured optical fibres (MOFs). Based on our results and the algorithms presented, one can determine the linear taper profile (starting and finishing pitch values and taper length) needed to achieve parabolic pulse shaping of an initial Gaussian pulse shape with different widths and powers. We quantify the evolution of the parabolic pulse using the misfit parameter and show that it is possible to reach values significantly better than those obtained by a step index fibre.

scholarly journals Stabilization of Plasma Glucose: The Use of Newer Technology and Pragmatic Laboratory Practice

2019 ◽  
Vol 3 (6) ◽  
pp. 1028-1034
Author(s):  
Stephen M Coward ◽  
Fiona C O'Neill ◽  
Leanne McAdam ◽  
Lynsey Reilly ◽  
Gareth C McKeeman
Keyword(s):  
Plasma Glucose ◽  
Fasting Glucose ◽  
Laboratory Practice ◽  
Target Values ◽  
Significant Difference ◽  
The Stability ◽  
Mean Glucose ◽  
And Storage ◽  
Glucose Analysis ◽  
Better Than

Abstract Background The target values for plasma glucose concentrations for the investigation and diagnosis of diabetes and impaired fasting glucose, and the realization that small incremental changes in glucose concentration increase the risk of adverse events, has led to greater focus on laboratory glucose results. Although analytical methods show acceptable precision, the control of preanalytical error due to the stability of glucose remains problematic. The aim of this study was to compare glucose concentrations in 3 different and commercially available blood tubes, with analysis and storage under current practices and conditions. Methods Blood samples for glucose were obtained from consenting patients attending the Diabetic Clinic at the Royal Victoria Hospital, Belfast. Blood was collected into BD Vacutainer® Barricor™ Lithium Heparin tubes, BD Vacutainer Fluoride EDTA tubes, and Greiner Vacuette® FC-Mix (sodium fluoride/citrate/Na2EDTA) tubes in that order. The Barricor tubes were immediately centrifuged at 4000g for 3 min. All samples were then sent to the Biochemistry Laboratory for analysis on the same day, and again the following day after storage at 4 °C. Results There was no significant difference in mean glucose concentrations between immediately centrifuged Barricor and FC-Mix tubes when analyzed on day 0. Both tube types demonstrated higher mean glucose concentrations than traditional fluoride EDTA (F/EDTA) samples. Conclusions Both immediately separated Barricor and citrated FC-Mix plasma preserve glucose concentrations to the same extent, and better than F/EDTA preservative. These newer technologies involved offer pragmatic solutions to improved glucose analysis, allowing laboratories to choose the best option given the source of their samples.

scholarly journals Performance enhancement of self-compacting concrete in saline environment by hydrophobic surface protection

2019 ◽  
Vol 46 (8) ◽  
pp. 677-686 ◽  
Author(s):  
Mazen J. Al-Kheetan ◽  
Mujib M. Rahman ◽  
Muniswamappa N. Balakrishna ◽  
Denis A. Chamberlain
Keyword(s):  
Performance Enhancement ◽  
Hydrophobic Surface ◽  
Harsh Environments ◽  
Self Compacting Concrete ◽  
Saline Environment ◽  
Surface Protection ◽  
Water Based ◽  
Dry Conditions ◽  
Better Than

The purpose of this research is to enhance the performance of self-compacting concrete (SCC) to make it a more sustainable alternative to traditional concrete. SCC serves the purpose in harsh environments, therefore, requires protection against de-icing agents and harmful saline environments. This paper reports the results from a laboratory study evaluating the efficacy of two impregnants; pure-silane and water-based silane. Both materials were applied on dry and wet SCC specimens manufactured with high and medium doses of superplasticizer. When treatment is applied on dry samples, a significant reduction in chloride penetration was noticed. However, the impregnants were less effective when applied on specimens subjected to intermediate and long-term exposure to water. In dry conditions, pure-silane performed better than the water-based silane, although they had a similar performance when applied on wet specimens. In addition, increasing the internal moisture content has shown an adverse effect on the efficacy of both materials.

scholarly journals Development of methods for analysis of the amount of flavonoids and their stability study in the combined dental gel

2021 ◽  
pp. 3-10
Author(s):  
Yu. Maslii ◽  
A. Materiienko ◽  
O. Ruban ◽  
I. Bezruk ◽  
L. Ivanauskas
Keyword(s):  
Stability Study ◽  
Biologically Active Substances ◽  
Biologically Active ◽  
Plant Origin ◽  
Active Components ◽  
Drug Substances ◽  
The Stability ◽  
And Storage ◽  
Active Substances

An important aspect in the pharmaceutical development of dental medicines is to provide them with a prolonged therapeutic effect while reducing the side effects of drug substances and the possibility of long-term use. This can be achieved by using active components of plant origin. Aim. To develop methods for analyzing biologically active substances in the composition of a new combined dental gel. Materials and methods. The study object was a dental gel containing “Phytodent” complex tincture (PJSC “CPP Chervona zirka”, Ukraine). Based on the analysis of the composition of the tincture it was proposed to carry out standardization by the amount of biologically active substances, namely flavonoids. Identification was carried out by TLC, while the quantitative determination by absorption spectrophotometry, the ultraviolet and visible method by the reaction with aluminum chloride using the standard method calculated with reference to rutin and the absorbance measurement at 406 nm. Results and discussion. As a result of the research, the methods for the analysis of flavonoids in the composition of the new combined gel have been developed. The spectrophotometric method developed is characterized by specificity, accuracy, precision and linearity with r = 0.9998. One of the important issues when using components of plant origin is their stability both during preparation and storage. Using the method developed the stability of flavonoids has been studied depending on pH changes of the carbomer-based dental gel. Conclusions. It has been determined that the methods developed are easily reproducible and allow to identifying and quantifying flavonoids in the dental gel. It has been found that a stable content of flavonoids is characteristic of the carbomer-based gel neutralized to pH values from 5.0 to 6.0.

A high efficiency approach for a titanium surface antifouling modification: PEG-o-quinone linked with titanium via electron transfer process

2014 ◽  
Vol 2 (39) ◽  
pp. 6758-6766 ◽  
Author(s):  
Songtao Liu ◽  
Lijuan Chen ◽  
Lin Tan ◽  
Fuhu Cao ◽  
Longchao Bai ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Transfer Process ◽  
Self Assembly ◽  
Titanium Surface ◽  
High Efficiency ◽  
The Self ◽  
Electron Transfer Process ◽  
The Stability ◽  
Better Than

The stability and long-term antifouling properties of the electro-assembly monolayers of PEG-o-quinone are better than that of the self-assembly monolayers of PEG-catechol.

scholarly journals Effects of pH and Storage Time on the Stability of Papaya and Carrot Extracts

2019 ◽  
Vol 1 (1) ◽  
pp. 25
Author(s):  
Juliana Juliana ◽  
Renny Indrawati ◽  
Leny Yuliati
Keyword(s):  
Color Difference ◽  
Alkaline Condition ◽  
Natural Pigments ◽  
Treatment Conditions ◽  
Effects Of Ph ◽  
Color Degradation ◽  
The Stability ◽  
And Storage ◽  
Freeze Dryer ◽  
Better Than

Papaya and carrot are rich in natural pigments, especially b-carotene. Unfortunately, in most cases, natural pigments are less stable than the synthetic ones when they are put in a variety of treatment conditions, such as pH. In this work, the stability of the papaya and carrot extracts were evaluated in various pH, which ranges of 1-10 for 7 days. The extracts were obtained by a slow juicer, followed by encapsulation and drying by a freeze dryer. The extracts were then dispersed in buffer solutions and the chroma and color difference (DE) values were calculated from the obtained lightness (L*), redness (a*), and yellowness (b*). The results showed that carrot extract was better than the papaya extract in terms of chroma values. It was also shown that both extracts were not stable under acidic condition, but more stable in neutral to alkaline condition. The acid condition facilitated the cleavage of the conjugated bonds in the b-carotene, which in turn caused the color degradation in the papaya and carrot extracts.

Human plasma stability during handling and storage: impact on NMR metabolomics

The Analyst ◽  
2014 ◽  
Vol 139 (5) ◽  
pp. 1168-1177 ◽  
Author(s):  
Joana Pinto ◽  
M. Rosário M. Domingues ◽  
Eulália Galhano ◽  
Cristina Pita ◽  
Maria do Céu Almeida ◽  
...  
Keyword(s):  
Human Plasma ◽  
Room Temperature ◽  
Storage Conditions ◽  
Plasma Composition ◽  
Long Term Storage ◽  
Short And Long Term ◽  
The Stability ◽  
And Storage ◽  
Term Storage

The stability of human plasma composition was investigated by NMR, considering different collection tubes, time at room temperature (RT), short- and long-term storage conditions and up to 5 consecutive freeze–thaw cycles.

A Turbulence Scheme with Two Prognostic Turbulence Energies

2018 ◽  
Vol 75 (10) ◽  
pp. 3381-3402 ◽  
Author(s):  
Ivan Bašták Ďurán ◽  
Jean-François Geleyn ◽  
Filip Váňa ◽  
Juerg Schmidli ◽  
Radmila Brožková
Keyword(s):  
Boundary Layer ◽  
Three Dimensional ◽  
Atmospheric Model ◽  
Stability Parameter ◽  
Convective Boundary ◽  
Stability Range ◽  
Single Column ◽  
The Stability ◽  
Better Than

A new turbulence scheme with two prognostic energies is presented. The scheme is an extension of a turbulence kinetic energy (TKE) scheme following the ideas of Zilitinkevich et al. but valid for the whole stability range and including the influence of moisture. The second turbulence prognostic energy is used only for a modification of the stability parameter. Thus, the scheme is downgradient, and the turbulent fluxes are proportional to the local gradients of the diffused variables. However, the stability parameter and consequently the turbulent exchange coefficients are not strictly local anymore and have a prognostic character. The authors believe that these characteristics enable the scheme to model both turbulence and clouds in the planetary boundary layer. The two-energy scheme was tested in three idealized single-column model (SCM) simulations, two in the convective boundary layer and one in the stable boundary layer. Overall, the scheme performs better than the standard TKE schemes. Compared to the TKE schemes, the two-energy scheme shows a more continuous behavior in time and space and mixes deeper in accordance with the LES results. A drawback of the scheme is that the modeled thermals tend to be too intense and too infrequent. This is due to the particular cutoff formulation of the chosen length-scale parameterization. Long-term three-dimensional global simulations show that the turbulence scheme behaves reasonable well in a full atmospheric model. In agreement with the SCM simulations, the scheme tends to overestimate cloud cover, especially at low levels.

scholarly journals Effects of Molecular Weight and Degree of Esterification of Soluble Soybean Polysaccharide on the Stability of Casein under Acidic Conditions

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 686
Author(s):  
Hao Tian ◽  
Qizhu Zhao ◽  
Zhiyong He ◽  
Zhaojun Wang ◽  
Fang Qin ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Average Particle Size ◽  
Average Particle ◽  
Degree Of Esterification ◽  
Long Term Storage ◽  
Acidic Conditions ◽  
The Stability ◽  
And Storage ◽  
Term Storage

The effects of molecular weight (MW) and degree of esterification (DE) of soluble soybean polysaccharide (SSPS) on the stability of casein under acidic conditions were investigated. The ability of SSPS to stabilize casein was characterized by the content of SSPS–casein complex, the LUMiSizer instability index, average particle size, zeta potential, and storage experiments. The long-term storage stability of the mixtures was related to their ability to combine casein and the stability of the complexes. At the same DE, SSPSs with medium MW formed more complexes with casein than SSPSs with high or low MW; and at the same MW, SSPSs with medium or low DE formed more complexes than SPSSs with high DE. In addition, SSPSs with higher MW had a better stabilizing behavior due to the large steric repulsion between complexes. SSPSs with high MW and low DE showed the best ability to stabilize casein under acid conditions.

Preparation, Stabilization and Some Properties of Purified Human Plasmin*

1964 ◽  
Vol 11 (01) ◽  
pp. 075-084 ◽  
Author(s):  
Daniel L Kline ◽  
Jacob B Fishman ◽  
Keyword(s):  
Plasminogen Activator ◽  
Stable Form ◽  
Neutral Ph ◽  
The Stability ◽  
And Storage

Summary1. Lysine increased the solubility, decreased the SK requirement and increased the stability of plasmin prepared from purified plasminogen by SK activation.2. A procedure is presented for the rapid and quantitative conversion of plasminogen to plasmin and storage of the plasmin in stable form at neutral pH as a lyophilized powder.3. Approximately 10% for the plasminogen molecule was split off during its activation. No carbohydrate was lost.4. The plasmin isolated was homogeneous in the ultracentrifuge at pH 2.5 and was quantitatively convertible to plasminogen activator by the addition of SK.

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