Rapidity Of Measurement Research Articles

Location of reinforcement and moisture assessment in reinforced concrete with a double receiver GPR antenna

Ground Penetrating Radar (GPR) is a popular technique in Civil Engineering for non-destructive investigations and more especially for the diagnosis of reinforced concrete structures. Its main applications are for the location of reinforcement and for measuring the thickness of elements. The advantage of GPR compared to other techniques, such as the use of a covermeter, is its rapidity of measurement, which allows large surfaces to be covered in a shorter time than with magnetic techniques. However, in a comparison with covermeters, the main disadvantage of GPR is the difficulty of accurately assessing the depth of reinforcement without advanced processing, or/and calibration.In this study, we propose a new methodology for GPR measurement and processing that allows accurate location of reinforcement in depth and an assessment of wave velocity inside the cover concrete at the same time. The new method of measurement employs a double offset configuration by using two bi-static antennas.A specific algorithm was developed for the determination of reinforcement depth and velocity inside cover concrete at the same time. The algorithm is tested on a 3 m × 3 m reinforced concrete slab with cover thickness ranging from 15 to 80 mm. With the algorithm, it is possible to measure the depth of reinforcement to within less than 2 mm, whatever concrete thickness.By using a calibration procedure specifically developed in this study, the velocity can be used to assess the water content inside cover concrete with a core conditioned at different moisture contents. A conversion model is obtained between water content and velocity measured by transmission, which can be used at different places in the structure to assess moisture.

Characterization of Petroleum Crude Oils using Laser Induced Fluorescence

The use of laser induced fluorescence (LIF) spectroscopy to characterize crude oil has privileges compared to conventional techniques in terms of reducing the size of sample, rapidity of measurements, high sensitivity and simplicity of sample handling and possibility of in situ measurements. The fluorescence radiation emitted from crude oil is the result of the interaction between the aromatic compounds and the electromagnetic radiation. The fluorescence spectra and their intensities are directly affected by the chemical composition and physical properties of the investigated samples. Important fluorescent information might be lost with the use of a single excitation wavelength, but might be obtained using other excitation wavelengths and thus enhancing the technique’s discrimination capability between different crude oil samples. For this reason, fluorescence spectra in the present work were obtained using four types of CW lasers as excitation sources. Five dry crude oil samples with American Petroleum Institute (API) gravities between 18 and 44 were diluted to 5 mg/l using chlorinated solvent. The excitation of the samples was performed using diode pumped solid state lasers (DPSS) emitting at 266 nm, 405 nm, 532 nm and an argon ion laser at 488 nm. The present work introduces for the first time the usage of laser induced fluorescence spectroscopy in the characterization of Egyptian crude oils. The results revealed the dependence of the emitted fluorescence on the physical and chemical properties of the oil samples including the API gravity, viscosity, sulphur and asphaltene contents. Thus, it is feasible to make use of LIF as a simple and fast spectrochemical analytical technique in differentiating between different types of crude oil.

Measuring Changes in Tactile Sensitivity in the Hind Paw of Mice Using an Electronic von Frey Apparatus

Measuring inflammation-induced changes in thresholds of hind paw withdrawal from mechanical pressure is a useful technique to assess changes in pain perception in rodents. Withdrawal thresholds can be measured first at baseline and then following drug, venom, injury, allergen, or otherwise evoked inflammation by applying an accurate force on very specific areas of the skin. An electronic von Frey apparatus allows precise assessment of mouse hind paw withdrawal thresholds that are not limited by the available filament sizes in contrast to classical von Frey measurements. The ease and rapidity of measurements allow for incorporation of assessment of tactile sensitivity outcomes in diverse models of rapid-onset inflammatory and neuropathic pain as multiple measurements can be taken within a short time period. Experimental measurements for individual rodent subjects can be internally controlled against individual baseline responses and exclusion criteria easily established to standardize baseline responses within and across experimental groups. Thus, measurements using an electronic von Frey apparatus represent a useful modification of the well-established classical von Frey filament-based assays for rodent mechanical allodynia that may also be applied to other nonhuman mammalian models.

Measuring Changes in Tactile Sensitivity in the Hind Paw of Mice Using an Electronic von Frey Apparatus

Measuring inflammation-induced changes in thresholds of hind paw withdrawal from mechanical pressure is a useful technique to assess changes in pain perception in rodents. Withdrawal thresholds can be measured first at baseline and then following drug, venom, injury, allergen, or otherwise evoked inflammation by applying an accurate force on very specific areas of the skin. An electronic von Frey apparatus allows precise assessment of mouse hind paw withdrawal thresholds that are not limited by the available filament sizes in contrast to classical von Frey measurements. The ease and rapidity of measurements allow for incorporation of assessment of tactile sensitivity outcomes in diverse models of rapid-onset inflammatory and neuropathic pain as multiple measurements can be taken within a short time period. Experimental measurements for individual rodent subjects can be internally controlled against individual baseline responses and exclusion criteria easily established to standardize baseline responses within and across experimental groups. Thus, measurements using an electronic von Frey apparatus represent a useful modification of the well-established classical von Frey filament-based assays for rodent mechanical allodynia that may also be applied to other nonhuman mammalian models.

Study on Dynamic Analysis of WT for Ceramic Paste Inner Stress

The distribution of ceramic paste inner stress was studied based on the dynamic wavelet analysis in this paper. According to the pressure signal between the vacuum pug mill and ceramic paste, the distribution of ceramic paste inner stress could be obtained. By adjusting the motor speed of vacuum pug mill, the mutational pressure signal and transient pressure signal from the head wall of vacuum pug mill were extracted, and then the time resolution and frequency resolution were adjusted by WT so that the pressure signal could be analyzed real-timely. Experimental results showed that WT can be used to analyze the different dynamic performance about the pressure signal between the vacuum pug mill and ceramic paste and its time delay was only equivalent to the width of mother function of WT, it ensured the rapidity of measurement about the distribution ceramic paste inner stress.

Microwave Tomographic approach for masonry investigation: some real results

Abstract. Ground Penetrating Radar (GPR) is an electromagnetic technique very appreciated by the community of the archaeologist and cultural heritage end-users community thanks to its appealing features in terms of non invasivity and rapidity of measurement and diagnostics. However, GPR data requires a high operator expertise in the data processing and interpretation. In the archaeological investigation, this drawback can be mitigated by the availability of a priori information about the archaeological scenario. On the other hand, in the case of the historical heritage, when the knowledge of constructive modalities and material of the structure may be completely missed, it is necessary to undertake other strategies of processing and interpretation. One of these can be provided by the use of novel inversion algorithms such as the Microwave Tomography (MT) which allows to reduce the subjectivity and the time consuming during the data processing. In this paper the MT was applied on raw data collected at two historical buildings of Chania (Crete, Greece). The first edifice is the Venizelo's House affected by visible fractures in its walls made up of cemented irregular stones. The second one is the headquarters of Prefecture of Chania showing some fractures along the floors. For these raw data, microwave tomography provided well detailed images which allowed to infer the fracture geometry and their extension in the host medium. This suggests microwave tomography can be a reliable complete processing tool requiring only the definition of the background scenario in terms of the dielectric permittivity and the conductivity of the host medium.

Evaluation of resin and fatty acid concentration levels by online sample enrichment followed by atmospheric pressure chemical ionization-mass spectrometry (APCI-MS)

In papermaking, there is a continuous interest both to minimize fresh water consumption and to reduce discharges into the environment. These general trends mean an increase in the amounts of detrimental substances, such as resin and fatty acids, in papermaking process waters. Resin acids, in particular, are responsible for much of the toxicity typically present in paper mill effluents and, for this reason, the routine and rapid monitoring of these compounds in various process streams is necessary. This also means that there is a continuous need to develop straightforward offline and online techniques to clarify problems occurring, for example, as a result of the introduction of more intensively closed systems of water circulation. In the present study, we describe the use of a novel, online, sample enrichment technique followed by atmospheric pressure chemical ionization-mass spectrometry (APCI-MS) suitable for monitoring the concentration levels of common resin and fatty acids in papermaking process waters. The representative process water samples were taken from the grinding zone of a thermomechanical pulping mill. The samples were first preconcentrated in a precolumn C18, and the analytes were transferred online to MS. The high intensive [M-H](-) ion was used for the identification of each analyte since, according to the present ionization method, no other fragmentation was observed. Laboratory-scale, online measurements with an online sample feed were carried out by connecting a centrifugal pump and a ceramic filter to the APCI-MS. Quality parameters, such as repeatability, linearity, and limit of detection (LOD), were determined by using dehydroabietic acid (DHAA) in order to evaluate the suitability of the method for the rapid screening of concentration levels. This method provided satisfactory linearity and a good correlation between analyte concentration and peak area. The suitability of the system for the continuous analysis of the same acids was evaluated in laboratory-scale, online experiments. In all cases, the response to changes in the analyte concentration was linear, and the repeatability of the system was also satisfactory. Only a few studies have been published on the analysis of resin and fatty acids with MS techniques. The present method was applied to the monitoring of dehydroabietic, oleic, and stearic acids. The quality parameters were highly comparable with those reported earlier, and the LOD values of the DHAA were below the levels usually encountered in process waters. The quality parameters were only slightly higher than those obtained by the traditional methods of analysis, probably due to the absence of an effective sample clean-up before analysis. The results of the laboratory-scale, online experiments indicated that the online enrichment APCI-MS system is a suitable alternative for monitoring the concentration levels of selected resin and fatty acids in papermaking process waters. The method can be used, for example, to provide useful information about the concentration levels of these acids in different stages of the process, thus signaling possibly impending problems. In general, faster and simpler measurements are needed to meet the requirements for a reduction in fresh water usage in papermaking. Compared to the conventional methods used for this purpose, the main benefits of the method are rapidity of measurement, simplicity of use, and absence of the need for multistage sample treatments (short analysis time). For this reason, this online method is more suitable for the control of papermaking by analyzing the concentration levels of interfering substances (i.e., selected resin and fatty acids) than an offline analysis detailing all the individual extractives-based compounds in process streams. It is also obvious that the technique can easily be modified for other environmental pollutants as well.

Paramagnetic particle detection for use with an immunoassay based biosensor

A biosensor and detection system that can provide measurement of analyte concentration within a test sample in four minutes is presented. The biosensor uses an immunoassay with micrometre-sized paramagnetic particle (PMP) labels for quantification. An immunoassay relies on the specific interaction between an antigen (analyte) and the corresponding antibody to immobilise the antigen to a substrate for measurement. In this system, the test samples and PMP labels are added to a reaction vessel on the biosensor and are attracted to a reaction surface at the base of the vessel using an electromagnet, where specific binding takes place. Unlike other immunoassay systems no extra washing or processing procedures are required. The bound labels, and associated antigen are detected, in situ, using a detector coil on the surface of the biosensor. The incorporation of a second coil under the biosensor allows for compensation for environmental changes such as thermal drift. The measurement of the resonant frequency of the detector coil in a parallel resonant circuit, prior to and after addition of the sample, provides a measure of the antigen in the sample. Good frequency stability is provided by the use of a phase locked loop arrangement. The resulting sensitivity was 1.17 µg of PMP labels per 1 Hz of frequency change and the minimum mass of PMPs detected was 62.5 µg. To demonstrate the utility of the technology and the rapidity of measurement, a model immunoassay for Troponin I (a cardiac marker) was used and discrimination at the clinically relevant value of 0.5 ng/ml Troponin I was achieved.

An amperometric immunosensor based on an electrochemically pretreated carbon–paraffin electrode for complement III (C 3) assay

An electrochemical immunosensor based on the adsorption of anti-complement III antibody onto an electrochemical pretreated carbon–paraffin electrode has been proposed for the detection of complement III (C 3). The competitive immunoassay format was adopted with horseradish peroxide–C 3 (HRP–C 3) as a tracer, 3,3′5,5′-tetramethylbenzidine (TMB) and hydrogen peroxide as the enzyme substrates. In order to measure the amount of HRP–C 3 binding onto the electrode surface, the product of the enzyme catalytic reaction was detected at 100 mV (vs. Ag/AgCl reference electrode). The system was optimized to realize a reliable determination of C 3 in the range of 0.06–10 μg/ml. It exhibits some advantages, such as simplicity of fabrication, rapidity of measurement, and satisfactory sensitivity and reproducibility.

An amperometric immunosensor based on a conducting immunocomposite electrode for the determination of Schistosoma japonicum antigen.

A renewable amperometric immunosensor based on a graphite-paraffin-Schistosoma japonicum antibody (SjAb) biocomposite electrode has been prepared for the detection of Schistosoma japonicum antigen (SjAg). Competitive ELISA was employed involving HRP-SjAg as a tracer and 3,3',5,5'-tetramethylbenzidine (TMB) as a substrate. The product of an enzyme catalytic reaction was detected at +0.1 V (vs. Ag/AgCl reference electrode) for measuring the amount of HRP-labeled SjAg binding to the electrode surface. The assay conditions were optimized, including the amount of SjAb loading in the electrode and HRP-SjAg in the incubation solution, the pH of the measuring solution and the incubation time. The measuring range was 0.5-30 microg/ml under the optimum conditions. Rabbit serum samples of different infection degree were measured, which demonstrated that the immunosensor meets the demands of clinical analysis. It exhibits some advantages, such as simplicity of fabrication, rapidity of measurement, and satisfactory sensitivity and reproducibility.

Laser mass spectrometry for environmental and industrial chemical trace analysis

Resonant laser mass spectrometry is a promising method for chemical trace analysis since it combines selectivity, sensitivity and rapidity of measurement. It is a two-dimensional technique incorporating medium- or high-resolution UV spectroscopy and time-of-flight mass spectrometry. No sample preparation and chemical clean-up is necessary to reach detection limits in the sub-ppb range even when highly complicated mixtures of chemical species are analyzed. After an introduction to the principles of resonant laser mass spectrometry, illustrative examples of applications are presented. Drawbacks, possibilities of overcoming them, some interesting features and future developments of resonant laser mass spectrometry are discussed.

Determination of the Ti speciation in commercial kaolins by Raman spectroscopy

AbstractRaman spectra of a selection of kaolins with widely varying TiO2 contents revealed the presence of anatase in 17 of 18 samples. A significant positive correlation was observed between the intensity of the main anatase Raman band at ~145 cm-1 and the total TiO2 contents of the kaolins as determined by chemical analysis. No TiO2 modification other than anatase was detected in any of the samples.The determination of the anatase contents in kaolins by XRD becomes increasingly difficult as the concentration of this mineral decreases below ~0.5%. In contrast, anatase and brookite concentrations an order of magnitude lower can still be readily identified by Raman spectroscopy. The specificity and sensitivity of Raman spectroscopy for these TiO2 polymorphs, coupled with the simplicity and rapidity of measurement, therefore make this a viable technique for the routine study of these accessory minerals in kaolins.

Analysis of heat and mass transfer processes in systems of dynamic thermovacuum hydrometry

A theoretical model of the process of moisture desorption in evacuation of a sample of moist material is proposed. An interrelationship between the operating conditions of the process and the material characteristics is shown. A new method of thermovacuum hydrometry that makes it possible to improve the rapidity of measurements and to significantly extend the measurement range for the moisture content of loose materials is described.

Using Ground-Penetrating Radar and Dielectric Probe Measurements in Pavement Density Quality Control

Ground-penetrating radar and capacitance-based dielectric surface probe measurements are used to measure fluctuations in voids, bitumen content, or both, in newly asphalted pavements without causing structural damage. Both methods rely on the compaction of asphalt to reduce the proportion of low-dielectricity air in the material, which increases the volumetric proportions of high-dielectricity bitumen and rock and thus results in higher asphalt dielectricity values. Ground-penetrating radar enables pavement thickness to be measured rapidly from a moving vehicle and information on variations in pavement voids content to be collected simultaneously on the basis of dielectricity fluctuations. The results can be calibrated against real void content by material sampling or by comparison of dielectric value with voids content values determined beforehand for the same material under laboratory conditions. This means that the subcontractor can be informed quickly of any values that exceed or fall below the norms and can take immediate steps to rectify such defects. Other advantages offered by the technique are the rapidity of the measurements and the immediate availability of the results. In addition, the one measurement provides simultaneous information on pavement and base thicknesses and the quality of the latter. The dielectric probe based on capacitance measurements lends itself to use in asphalt mass proportioning examinations performed at the laboratory stage, which enables the values to be used directly for monitoring in situ pavement compaction. The advantages of the dielectricity probe are rapidity of measurement, low-cost meters, and the avoidance of radiation. Thus far, the probe has been excessively sensitive to variations in the roughness of pavement surfaces. The theory behind these research methods is discussed, the methods are described, and the results of laboratory tests conducted at the Texas Transportation Institute in 1994–1995 and field tests performed in Finland in 1995 are presented.

Europium(III) cryptate: A fluorescent label for the detection of DNA hybrids on solid support

We report here a new detection method for DNA hybrids on dot blots. The process utilizes DNA or oligonucleotide probes labeled with biotin, followed by recognition with a conjugate of streptavidin and europium cryptate, a time-resolved fluorescent label. Unlike the other lanthanide chelates, this label is an organic molecule embedding a europium ion into an intramolecular cavity. This structure has a better stability in diluted assay media, a good sensitivity even on solid support, and an elevated fluorescence lifetime which allows elimination of most of the background generated by other species present in the assay medium. This procedure is quantitative and detects down to 2 amol of a model DNA, which is similar to other nonisotopic (especially colorimetric) methods. The main advantages of this method are easy automation, quantitation, and rapidity of measurements.

Absolute thermal expansion measurements of single-crystal silicon in the range 300?1300 K with an interferometric dilatometer

The thermal expansion coefficient of single-crystal silicon has been measured in the range 300–1300 K using an interferometric dilatometer. The measurement system consists of a double-path optical heterodyne interferometer and a radiant image furnace with a quartz vacuum tube, which provides both accuracy and rapidity of measurement. The uncertainties in length and temperature determination are within 4 nm and 0.4 K, respectively. A high-purity dislocation-free FZ silicon single crystal was used in the study. Thermal expansion coefficients of silicon oriented in the [111] direction have been determined over the temperature range from 300 to 1300 K. The standard deviation of the measurement data from the best fitting for the fifth-order polynomial in temperature is 2.1×10−8 K−1. The present value for the thermal expansion coefficient agrees within 9×10−8K−1 with the interferometric measurement of polycrystalline pure silicon by Roberts (1981) between 300 and 800 K and within 1.2 × 10−7 K−1 with the single-crystal X-ray diffractometric measurement by Okada and Tokumaru (1984) between 300 and 1300 K.

Attenuance rank is a rapid non-extractive measure of in vivo anthocyanin color and chlorophyll content of leaves of Corylus

A method was developed to quantify, without extraction, anthocyanin color expression and chlorophyll content in leaves of clones of Corylus. The method utilizes attenuance spectroscopy and non-parametric statistical analysis to rank in vivo leaf color. Comparisons with extraction procedures are made and inherent advantages with respect to color expression (versus extracted anthocyanin) and rapidity of measurement are discussed.

Optical properties of organic matter in relation to thermal gradients and structural deformation

The general response of macerals to the coalification process, the effectiveness of organic geochemical and petrological parameters as estimators of coalification and the applicability of different microscopical parameters in the assessment of rank are reviewed. The central role of vitrinite reflectance as the most widely used estimator of coalification from brown coals to the low -grade metamorphic zone is established on the basis of its relatively uniform variation with rank, specificity, ease and rapidity of measurement and cheapness. Factors influencing the optical properties ofvitrinites are considered. Temperature has the dominant influence in modifying optical properties with rank, but time, static pressure and stress can all have significant influences upon the course of optical properties, depending upon particular geological conditions. Static pressure has a retarding effect on the coalification process, but it is also responsible for creating increasing anisotropy within the condensing aromatic structures as rank rises. Hydrostatic pressures and pore pressures can contribute to the overpressuring of sediments, thus affecting their thermal conductivities and consequently the rate of coalification. Stress is responsible for the development of biaxicity in the reflectance indicatrix. Fast and high levels of heating from igneous bodies cause textural effects on vitrinites as a result of carbonization that are quite different from those of coalification. Recognizing these different influences upon the optical properties of vitrinites, examples are given of the use and application of vitrinite reflectance in the preparation of rank maps, in the burial histories of basins, in the timing of coalification in relation to orogenesis and igneous activity and in the zones of anchimetamorphism and low-grade metamorphism. Consideration is also given to the problem of ‘provincialism ’ in correlations between chemical and physical parameters and to the future development of optical studies in organic petrology and their relation to organic geochemical investigations.

A pulsed low resolution NMR study on crystallization and melting processes of cocoa butter

AbstractPulsed low resolution nuclear magnetic resonance (NMR) was employed to measure the «melting» curves of different series of cocoa butter samples. The samples were prepared from completely liquid phase by cooling and tempering them at different temperatures Tc for varying time Δt. The «melting» curves were measured while keeping the sample at a fixed temperature Tm. The complex shape of each curve was interpreted in terms of cocoa butter polymorphism, and the results were compared with data obtained by other techniques available in the literature. Using just two tempering temperatures (+7 C and −18C), we were able to distinguish four solid phases and identify them with the phases II, III, IV, and V described in literature. Our data are in full agreement with literature. Several novel results have been also found. These include the kinetic constants of the melting processes of phases II and III, the rate constants of solidification of phase V, the conversion of phase III into phase IV before melting at temperatures ≥30 C, and the growth of phase V out of phase II at −18 C (including the rate constant of this process). We are convinced that NMR may serve as a principal tool in fat polymorphism investigations, especially if it is combined with other techniques such as differential scanning calorimetry. Its advantage, apart from rapidity of measurement, is the fact that the measurement itself does not interfere with the melting or solidification process studied. On the other hand, it does not distinguish in a direct way between different solid phases present in the sample; this can be done only in inference from the behavior upon melting.

Pressure Chamber and Air Flow Porometer for Rapid Field Indication of Water Status and Stomatal Condition in Wheat

SUMMARYPlant water potential and leaf diffusive conductance, key features of plant responses to water stress in field experiments, can be estimated, respectively, by xylem pressure potential measured with the pressure chamber apparatus, and leaf permeability measured with the air flow porometer. This paper describes modifications to these two techniques in order to increase the rapidity of measurements in wheat to 60/h with the pressure chamber, and 200/h with the porometer. Rapid measurements are needed because of the large within-and between-plot errors encountered with daytime measurements in typical field experiments, examples of which are presented.