Method For Measurement Of Concentration Research Articles

Comparison of VIDAS and Radioimmunoassay Methods for Measurement of Cortisol Concentration in Bovine Serum

Radioimmunoassay (RIA) is the “gold standard” method for evaluation of serum cortisol concentration. The VIDAS cortisol test is an enzyme-linked fluorescent assay designed for the MiniVidas system. The aim of this study was to compare the VIDAS method with RIA for measurement of bovine serum cortisol concentration. Cortisol concentrations were evaluated in 40 cows using both VIDAS and RIA methods, the latter as the reference method. A paired Student's t-test, Pearson's correlation analysis, Bland-Altman plot, and Deming regression analysis were used to compare the two methods. There was no statistically significant difference between mean serum cortisol concentrations measured by VIDAS or RIA methods (P = 0.6570). Both methods were able to detect significant differences in mean low and high cortisol concentrations (P < 0.00014 RIA and P < 0.0016 VIDAS). The correlation coefficient was low, but a Bland-Altman plot and Deming regression analysis show neither constant nor proportional error. The VIDAS method produced slightly higher values than RIA, but the difference was small and in no case did the mean value move the normal range. Results suggest that VIDAS method is suitable for the determination of bovine serum cortisol concentration in studies of large numbers of animals.

A Novel HGB Concentration Measurement Method Based on Single-wavelength Spectrophotometry

A Novel HGB Concentration Measurement Method Based on Single-wavelength Spectrophotometry

Techniques of Functional and Motility Test: How to Perform and Interpret Intestinal Permeability

Transport of molecules across the intestinal epithelium takes place through 2 major routes, ie, trans-cellular and paracellular. Assessment of intestinal permeability is performed to assess the overall function of transport through the intestinal epithelial paracellular route. Urinary excretion of disaccharides and monosaccharides and ratio of their excretion is a basis for measurement of intestinal permeability. Lactulose and mannitol ratio is the most commonly used test for assessment of small intestinal permeability and the most reliable method for measurement of concentration of lactulose and mannitol in the urine is high performance liquid chromatography. After the measurement of concentration of probes in the urine; the results are expressed as the ratio of percentage excretion of the ingested dose of lactulose and mannitol in the urine. Testing of intestinal permeability is not required for routine patient care, however it is an important tool to understand the function of the paracellular transport in the research setting. Increase in intestinal permeability has been implicated in the pathogenesis of many autoimmune diseases including celiac disease, Crohn's disease, type I diabetes and food allergy.

Odour Impact Assessment in Industrial Areas

Odours emitted by multi-source facilities, like industrial complexes, have become a major concern for local authorities because the resulting annoyance in the neighbourhood is generally high compex compared to a single source one. In the case of such multi-source odour emissions especially, common chemical analyses or odour concentration measurement methods are not often applicable.This paper describes the methodology adopted for assessing the odour impact on the industrial area of the city of Salerno (Italy), caused by the co-presence of two strategic plants: wastewater treatment plant and composting plant of organic fraction of solid waste. The combination of olfactometric analyses and dispersion modelling allowed both the quantification of the odour emissions and the evaluation of their potential impact on the surrounding areas. Odour impact criteria, input parameters and emissive rate were evaluated. Results discuss and compare different emissive scenarios to assessment odour impacts in the industrial area.

Waveguide Two-Point Differential-Excitation Method for Quantitative Absorption Measurements of Nanostructures

To establish a new useful quantitative absorption measurement method for nanostructures, we investigated quantitative accuracy of a recently developed waveguide two-point differential-excitation method, which combines Fabry–Pérot fringe analysis and attenuated internal emission analysis for differential-path-length excitations. Quantitative absorption spectra of an 8-nm-thick GaAs quantum well at various temperatures consistent with theoretical predictions are demonstrated within 5% relative accuracy and a high dynamic range of 0–210 cm-1 in modal absorptions. The results were also compared with conventional photoluminescence excitation spectra of the same sample, which turned out to underestimate the absorption peak intensity of the lowest exciton at low temperatures.

삼나무 정유의 표재성 진균에 대한 항진균 활성

본 연구에서는 표재성 진균에 의한 피부질환 개선용 소재로의 개발을 위해 삼나무 정유의 표재성 알레르기성 진균, Trichophyton schoenleinii, Trichophyton tonsurans, Trichophyton mentagrophytes (interdigitale), Trichophyton rubrum, Epidermophyton floccosum, Aspergillus fumigatus에 대한 항진균 활성을 평가하여 삼나무 정유의 표재성 진균에 의한 피부질환 개선 소재로의 개발 가능성을 평가하고자 하였다. 항진균 활성 평가는 삼나무 정유의 MIC (Minimum Inhibitory Concentration) 측정과 TLC bioassay, 한천희석법을 통해 측정하였다. 또한 활성 성분의 주성분을 확인하기 위해 GC/MS 분석을 실시하였다. 삼나무 정유 crude oil의 MIC는 모든 균에서 500 ppm 이하의 농도 값을 나타냈으며, TLC bioassay를 통해 spot 1에서 항진균 효과를 확인하였다. 한천희석법을 통한 항진균 활성은 A. fumigatus를 제외한 모든 진균에 대해 삼나무 정유 crude oil의 경우, 500 ppm 이상에서 100%의 활성을 나타냈고, 분획 D의 경우, 100 ppm에서도 100%의 활성을 나타냈다. TLC bioassay를 통해 항진균 활성을 나타낸 spot 1과 한천희석법을 통해 활성을 나타낸 분획 D를 GC/MS로 분석한 결과 주성분은 elemol, <TEX>${\gamma}$</TEX>-eudesmol, <TEX>${\beta}$</TEX>-eudesmol이었다. 따라서 elemol, eudesmol 등은 표재성 진균에 의한 피부질환의 개선 소재로의 이용 가능성이 충분하다고 사료된다. In this study, the antifungal activity of Cryptomeria japonica essential oil against superficial and allergic fungi, Trichophyton schoenleinii, Trichophyton tonsurans, Trichophyton mentagrophytes, Trichophyton rubrum, Epidermophyton floccosum, and Aspergillus fumigatus, was evaluated for determining the potential compound as dermatitis treatment. Minimum Inhibitory Concentration (MIC) measurement, TLC bioassay and agar dilution methods were used for determining the antifungal activity of crude essential oil and its fractions from C. japonica. Also, their major constituents were analyzed by GC/MS. The MICs were below 500 ppm at all superficial fungi, and spot 1 of C. japonica essential oil showed highly effective antifungal activity by TLC bioassay. In antifungal activity by agar dilution methods, crude oil showed high antifungal effect at more than 500 ppm and fraction D was significantly effective at even 100 ppm except for A. fumigatus. The major compounds of spot 1 and fraction D of C. japonica oil determined by GC/MS were elemol, <TEX>${\gamma}$</TEX>-eudesmol, and <TEX>${\beta}$</TEX>-eudesmol, which could be used as atopic dermatitis treatment material.

Protection Window Pollution Interference of the Monodispersion Soot on Measuring SO&lt;sub&gt;2&lt;/sub&gt; Concentration Using NDIR

The non-dispersive infrared absorption spectrum method is one of the important sulfur dioxide concentration measurement method. If the soot particles attach on the protection windows surface, the original measurement light intensity is attenuated because of the absorption and scattering of the soot particle and the sulfur dioxide concentration measurement accuracy is decreased. The protection window pollution question caused by the monodispersion soot particles is discussed in the paper. The numerical simulation results show that the sulfur dioxide concentration measurement accuracy is related to the protection window pollution. The solution method is brought out and the measurement accuracy can be improved.

Concentration measurements of biodiesel in engine oil and in diesel fuel

This work comprised a method for concentration measurements of biodiesel in engine oil as well as biodiesel in diesel fuel by a measurement of the permittivity of the mixture at a frequency range from 100 Hz to 20 kHz. For this purpose a special designed measurement cell with high sensitivity was designed. The results for the concentration measurements of biodiesel in the engine oil and diesel fuel shows linearity to the measurement cell signal for the concentration of biodiesel in the engine oil between 0.5% Vol. to 10% Vol. and for biodiesel in the diesel fuel between 0% Vol. to 100% Vol. The method to measure the concentration of biodiesel in the engine oil or the concentration of biodiesel in the diesel fuel is very accurate and low concentration of about 0.5% Vol. biodiesel in engine oil or in diesel fuel can be measured with high accuracy.

Evaluation of the fibrinogen antigenic turbidimetric assay as a screening method for measurement of fibrinogen concentration in dogs

A novel method for the rapid detection of fibrinogen concentration in human plasma, the fibrinogen antigenic turbidimetric assay (FIATA), is based on the precipitation of fibrinogen by vancomycin and a resultant change in optical density. The objectives of this study were to evaluate the FIATA method for: (1) measuring fibrinogen concentration in canine plasma using specimens collected in citrate, EDTA, and heparin, (2) species-specific calibration requirements, and (3) applicability for automation. Standard curves were generated with both human and canine fibrinogen standards in the FIATA, and a reference interval for fibrinogen concentration was established using citrated plasma from healthy dogs (n = 127). Using specimens collected from this population, results using the FIATA were compared with a modified thermoprecipitation method, and 24 of the FIATA samples were used for comparison with a particle-enhanced turbidometric fibrinogen assay. The FIATA was also applied to an automated chemistry analyzer using citrated plasma. Fibrinogen concentration was measured in EDTA and heparinized plasma in the manual FIATA. Standards, methods, and anticoagulants were compared, and correlation among these variables was evaluated. Significant differences between FIATA results using human and canine standards and the manual and automated methods were not found. For EDTA plasma, fibrinogen concentrations were not identical, but were similar, to those for citrated plasma; heparinized plasma was not suitable for measurement. Correlation between the thermoprecipitation method and FIATA was weak. The reference interval for fibrinogen as measured by the FIATA using citrated plasma was 103-456 mg/dL. The FIATA can be used as a screening method to measure fibrinogen concentration in citrated or EDTA plasma from dogs.

Simulation Study of Spiral Electrode Capacitance Sensor for Measuring Concentration of Gas-Solid Two-Phase Flow

Gas-sold two-phase flow is a typical and complex flow form in the natural world and the industrial process. The accurate measurement of the parameters is the key problem for improving the industry control quality and promoting enterprise economic benefit. Three-dimensional finite element simulation of spiral electrodes capacitance sensor was put up by ANSYS in this paper. The results from simulation show that spiral electrode capacitance sensor has an obvious advantage. The sensor has uniform sensing filled, and the capacitance value has nothing to do with flow pattern which is only related to solid concentration change. There is good linear correlation between capacitance value and solid concentration. Relationship graph between capacitance value and solid concentration was obtained by calculated. In addition, with the FEM the qualitative analyses to the effect of each structural parameter of the capacitance transducer on its capability were made. These can provide bases and supports for optimum design of this kind of sensors. Comparing with ECT, it is a simply and easy-implemented method of concentration measurement using spiral electrode capacitance sensor.

OH clock determination by proton transfer reaction mass spectrometry at an environmental chamber

Abstract. The hydroxyl free radical (OH) is the major oxidizing species in the lower atmosphere. Measuring the OH concentration is generally difficult and involves elaborate, expensive, custom-made experimental setups. Thus other more economical techniques, capable of determining OH concentrations at environmental chambers, would be valuable. This work is based on an indirect method of OH concentration measurement, by monitoring an appropriate OH tracer by proton transfer reaction mass spectrometry (PTR-MS). 3-pentanol, 3-pentanone and pinonaldehyde (PA) were used as OH tracers in α-pinene (AP) secondary organic aerosol (SOA) aging studies. In addition we tested butanol-d9 as a potential "universal" OH tracer and determined its reaction rate constant with OH: kbutanol-d9 = 3.4(±0.88) × 10−12 cm3 molecule−1 s−1. In order to make the chamber studies more comparable among each other as well as to atmospheric measurements we suggest the use of a chemical (time) dimension: the OH clock, which corresponds to the integrated OH concentration over time.

A novel method for measurement of concentration using two dimensional photonic crystal structures

A novel method to measure the concentration of sugar, sodium chloride and alcohol, in their aqueous solution by using two dimensional photonic crystal structures is presented. This measurement is very accurate as the principle is based on variation of photonic band gap with respect to concentration. Photonic band gap here is computed using plane wave expansion method.

Testing a passive method for measurement of surface ozone concentrations (Mondy Station, East Siberia)

The efficiency a new passive air sampling technique has been studied as a universal low-cost means of surface ozone monitoring. As a result of a half-year observation cycle, a large array of experimental data on surface ozone concentrations was collected using two techniques, i.e., the passive sampling and the optical technique. The efficiency of suggested passive ozone sampling technique is confirmed for long-term back-country measurements, particularly, for ROSHYDROMET stations.

MD2-1 Development of 2D temperature and concentration measurement method using tunable diode laser absorption spectroscopy(MD: Measurement and Diagnostics,General Session Papers)

MD2-1 Development of 2D temperature and concentration measurement method using tunable diode laser absorption spectroscopy(MD: Measurement and Diagnostics,General Session Papers)

The Precise Mechanisms of a High-Speed Ultrasound Gas Sensor and Detecting Human-Specific Lung Gas Exchange

In this paper, we propose and develop a new real-time human respiration process analysis method using a high-time-sampling gas concentration sensor based on ultrasound. A unique point about our proposed gas concentration sensor is its 1 kHz gas concentration sampling speed. This figure could not have been attained by previously proposed gas concentration measurement methods such as InfraRed, semiconductor gas sensors, or GC-MS, because the gas analysis speeds were a maximum of a few hundred milliseconds. First, we describe the proposed new ultrasound sound speed measurement method and the signal processing, and present the measurement circuit diagram. Next, we analyse the human respiration gas variation patterns of five healthy subjects using a newly developed gas-mask-type respiration sensor. This reveals that the rapid gas exchange from H2O to CO2 contains air specific to the human being. In addition, we also measured medical symptoms in subjects suffering from asthma, hyperventilation and bronchial asthma. The millisecond level high-speed analysis of the human respiration process will be useful for the next generation of healthcare, rehabilitation and sports science technology.

Soot Concentration Measurement System of the Stationary Pollution Source Using the Scattering-Transmission Method

The soot emitted from the stationary pollution source is one of the important atmospheric pollutants. The soot concentration is an important influence and can detect the total emissions condition of the pollution source. The new on-line Scattering-Transmission soot concentration measurement method is presented. The new method is based on the Scattering integration method and the Extinction theory. The measurement result of the new method is independent of the soot size distribution and the soot average size. The numerical simulation results based on Mie scattering theory confirmed the validity of the techniques. The measurement instrument based on this method is produced. The instrument is produced. The system uses 80C252 as the MCU, displays measurement result through LCD and transfers the measurement to the monitoring computer. Soot concentration measurement system is calibrated in one of the steel mill. The results showed the method is very reliable, high precision.

Set-up and calibration of a method to measure 10B concentration in biological samples by neutron autoradiography

A selective uptake of boron in the tumor is the base of Boron Neutron Capture Therapy, which can destroy the tumor substantially sparing the normal tissue. In order to deliver a lethal dose to the tumor, keeping the dose absorbed by normal tissues below the tolerance level, it is mandatory to know the 10B concentration present in each kind of tissue at the moment of irradiation. This work presents the calibration procedure adopted for a boron concentration measurement method based on neutron autoradiography, where biological samples are deposited on sensitive films and irradiated in the thermal column of the TRIGA reactor (University of Pavia). The latent tracks produced in the film by the charged particles coming from the neutron capture in 10B are made visible by a proper etching, allowing the measurement of the track density. A calibration procedure with standard samples provides curves of track density as a function of boron concentration, to be used in the measurement of biological samples. In this paper, the bulk etch rate parameter and the calibration curves obtained for both liquid samples and biological tissues with known boron concentration are presented. A bulk etch rate value of (1.64±0.02)μm/h and a linear dependence with etching time were found. The plots representing the track density versus the boron concentration in a range between 5 and 50μg/g (ppm) are linear, with an angular coefficient of (1.614±0.169)·10−3tracks/(μm2ppm) for liquids and (1.598±0.097)·10−2tracks/(μm2ppm) for tissues.

Mine Dust Concentration Measurement Method Based on Model of Dust Concentration and Humidity

According to the coal mine underground work place humidity changes affect the measurement precision of dust concentration, improper spray cause coal with the water loss and wastes a lot of water resources, the paper put forward a correction factor of dust concentration based on the relative humidity, establish the relation model of concentration and humidity. The test results show that: the dust concentration correction factor and relationship model of concentration and humidity are effective and scientific, it has better practicability to solve the problem of underground coal mine.

Quantification of Quantum Dot Concentration Using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

As quantum dot (QD) bioconjugates are increasingly being used for biomedical in vitro and in vivo studies, validated methods for the quantitative determination of QD concentration are of considerable potential value. In this work, we have assessed inductively coupled plasma mass spectrometry (ICP-MS) as a method for the quantitative detection of QDs and QD bioconjugates. We have established a linear relationship between the concentration of unconjugated QD and the mass of cadmium, selenium and zinc detected by ICP-MS. Furthermore, ICP-MS was used to quantitatively estimate the unknown concentration of a QD-antibody bioconjugate. Quantitative measurement of QD bioconjugate concentration was also attempted by optical methods, including fluorescence and absorbance, and compared to ICP-MS. Consistent with previous literature, the fluorescence of the nanoparticle construct was reduced after functionalization with a biomolecule (biotin or streptavidin). Optical absorbance of the QD is unaffected by chemical modifications in this study and is a reliable method to determine the concentration. Optical absorption in this application achieves nanomolar concentrations but is not suitable for most biomedical studies that require a nanoparticle detection limit in the sub-nanomolar region. Unlike optical absorbance and fluorescence, ICP-MS can reliably detect the concentration of QD bioconjugates in the nanomolar range, making ICP-MS a quantitative, sensitive method for QD concentration measurements even after surface conjugation and consequent changes in fluorescence characteristics.

In situ measurement of the mass concentration of flame-synthesized nanoparticles using quartz-crystal microbalance

A novel in situ method for measurement of mass concentration of nanoparticles (NPs) formed in flames is proposed. In this method, the deposition rate of NPs collected by a molecular beam sampling system is measured by quartz-crystal microbalance (QCM). It is the only existing method which allows direct measurement of NP mass concentration profiles in flames. The feasibility of the method was demonstrated by studying iron oxide NP formation in low-pressure methane/oxygen/nitrogen flames doped with iron pentacarbonyl. The system was tested under fuel-lean and fuel-rich flame conditions. Good agreement between measured QCM deposition rates and their estimations obtained by the transmission electron microscopy analysis of samples collected from the molecular beam has been demonstrated. The sensitivity of the method is comparable to that of particle mass spectrometry (PMS). Combination of the QCM technique with PMS and/or optical measurements can provide new qualitative information which is important for elucidation of the mechanisms governing the NP flame synthesis.