Instrument For On-line Measurement Research Articles

Using hybrid methodologies to characterize temporal behavior and source of ambient ammonia

For the areas with much less agricultural activities, it is hotly debatable whether the atmospheric ammonia (NH3) mainly comes from agricultural or non-agriculture sources. This paper chooses the city of Taichung, the second most populated city in Taiwan, to resolve this debate by analyzing the data of NH3, PM2.5-bound water-soluble ions, SO2 and NOx monitored from 2016 to 2018 through online measurement instruments. We conclude that a significant amount of NH3 came from agricultural sources in light of (1) the strong correlations between NH3 concentrations and temperature, (2) the weak correlations between NH3 concentrations and the traffic related pollutants (NOx) and industrial pollutants (SO2)), (3) the high conversion ratio of ammonium (NHR), and (4) high background source contribution to NH3 in multiple linear regression models. As to other sources of NH3, while less impactful than the agriculture sources, the coal combustion, iron ore and steel industry, and oil combustion are three majors local NH3 emissions to form PM2.5. The results of this study can help control and regulate PM2.5 in NH3-rich regions such as Taichung.

The Role of Loneliness and Self-Compassion as Predictors of Depressive Symptoms in College Students

High prevalence of depressive symptoms was found in college students. Loneliness, as one common problem incollege students, is assumed to have a role in the development of depressive symptoms. Earlier research foundself-compassion to be associated with better mental health. It is necessary to examine how loneliness and self-compassion play a role in the presence of depressive symptoms in college students. A total of 401 college studentsin the Jabodetabek area were involved in this research by completing online measurement instruments consistingof demographic questionnaire, 6-Item De Jong Gierveld Loneliness Scale, Self-Compassion Scale – Short Form,and Patient Health Questionnaire - 9. Data were analyzed using multiple regression analysis. Results showed thatloneliness had a significant role in predicting the increase in depressive symptoms, b = .374; t(392) = 7.68, p <.01, while self-compassion was able to predict the reduction of depressive symptoms in college students, b = -.353; t(392) = -7.15, p < .01. This study illustrates the importance of considering the quality of relationships anddeveloping self-compassion as an effort to reduce depression symptoms in college student

A New Portable Instrument for Online Measurements of Formaldehyde: From Ambient to Mobile Emission Sources

Formaldehyde (HCHO) plays an important role in atmospheric photochemistry, HOx budget, and ozone formation. Several instruments have been developed for measuring ambient HCHO, yet few have targeted...

Developing Soft Sensors for Polymer Melt Index in an Industrial Polymerization Process Using Deep Belief Networks

This paper presents developing soft sensors for polymer melt index in an industrial polymerization process by using deep belief network (DBN). The important quality variable melt index of polypropylene is hard to measure in industrial processes. Lack of online measurement instruments becomes a problem in polymer quality control. One effective solution is to use soft sensors to estimate the quality variables from process data. In recent years, deep learning has achieved many successful applications in image classification and speech recognition. DBN as one novel technique has strong generalization capability to model complex dynamic processes due to its deep architecture. It can meet the demand of modelling accuracy when applied to actual processes. Compared to the conventional neural networks, the training of DBN contains a supervised training phase and an unsupervised training phase. To mine the valuable information from process data, DBN can be trained by the process data without existing labels in an unsupervised training phase to improve the performance of estimation. Selection of DBN structure is investigated in the paper. The modelling results achieved by DBN and feedforward neural networks are compared in this paper. It is shown that the DBN models give very accurate estimations of the polymer melt index.

The Multi-Varieties Small-Batch Gas Monitor Flexible Digital Job Shop Design and Integration Technology Research

With the large-scale construction of city gas pipeline, increasing natural gas pipeline leakage accident disasters caused by the gas monitor is an important on-line measurement instrument for the safety operation of the network of natural gas, which has the characteristics of multi-varieties, style complex, complex procedures, automatic production, low digital level by making multi-varieties small-batch gas monitor as the main the mode of production. In order to solve that the traditional digital manufacturing job shop cannot meet the modern multi varieties and small-batch production of gas monitor manufacturing requirements, based on the complex production process of digital equipment, digital control, digital key technology, it proposes a gas monitor job shop solution based on intelligent manufacturing, construction of the implementation of the integrated framework and implementation activities of information flow model to realize the bottom equipment layer, design and manufacture of middle management and intelligent control layer. It has proved that multi-varieties small-batch of digital manufacturing job shop manufacturing process and development has a good application effect and can provide a reference model for the multi varieties small-batch manufacturing precision instruments in the production, greatly saving the production casting time cost, production cost and resource cost.

Comparative study of biogenic volatile organic compounds fluxes by wheat, maize and rapeseed with dynamic chambers over a short period in northern France

Biogenic volatile organic compounds (BVOC) are mainly emitted from vegetation. However there is still little information on BVOC exchanges with crops. In this study we measured fluxes of BVOC from wheat, maize and rapeseed crops near Paris at the plant level during a full-week period for each species. We used dynamic automated chambers coupled to a Proton Transfer Reaction, Quadrupole ion guide, Time of Flight mass spectrometer (PTR-Qi-Tof-MS) instrument for online measurements of BVOC. Our results confirm the hypothesis that many unexplored compounds contribute to BVOC exchanges between crops and the atmosphere, although for all plant species methanol was dominating the emissions (55–85% of the sum of the BVOC exchanges fluxes on a mass basis) followed by acetone and acetaldehyde. The 10 most exchanged compounds, excluding methanol, contributed more than 50% of the summed fluxes and the 100 most exchanged contributed to more than 90%. The summed BVOC emission and deposition presented large interspecies variations, but limited intra-species variability, with a summed net flux of 0.11 ± 0.02 μgBVOC gDW−1 h−1 for maize, 1.5 ± 0.7 μgBVOC gDW−1 h−1 for wheat, and 9.1 ± 2.4 μgBVOC gDW−1 h−1 for rapeseed. The 10 most emitted compounds were mostly emitted during the day and were correlated with both photosynthetically active radiation and temperature and anti-correlated with relative humidity. This study provides the first evaluation so far of the biosphere-atmosphere fluxes for several BVOC. In particular we provide a first evaluation of standard emission factor for isoprene and monoterpene for wheat and rapeseed at their respective growth stages. This study is however limited to a week period at a given stage for each species and at the plant level.

Analysis of the thermal properties of a heat flow chip calorimeter using CFD

The possibility of using a membrane chip calorimeter as an on-line measurement instrument depends on the condition that the calorimeter's characteristics are linear in the measuring range of flow rates. This condition is met when the heat conduction is considered only in the plane of the calorimeter membrane and the heat losses in other directions are assumed to be constant. The studies involving a 3D model of the commercial chip calorimeter were focused on the determination of a linear operating range of the calorimeter. To study the calorimeter properties a Computational Fluid Dynamics model of the calorimeter set-up has been developed using the ANSYS Fluent software. The CFD model has been calibrated for the calorimeter with an empty membrane, and then validated against the measured data for the calorimeter with a liquid sample on its membrane. Based on the measurement and simulated data, the static characteristic of the calorimeter and its properties have been determined. It was also possible to analyze the dynamic behavior of the system. The simulation results revealed a large variation in the dynamic properties of the calorimeter in the case of step changes in the heating power.

Aerosol mass spectrometry: particle–vaporizer interactions and their consequences for the measurements

Abstract. The Aerodyne aerosol mass spectrometer (AMS) is a frequently used instrument for on-line measurement of the ambient sub-micron aerosol composition. With the help of calibrations and a number of assumptions on the flash vaporization and electron impact ionization processes, this instrument provides robust quantitative information on various non-refractory ambient aerosol components. However, when measuring close to certain anthropogenic or marine sources of semi-refractory aerosols, several of these assumptions may not be met and measurement results might easily be incorrectly interpreted if not carefully analyzed for unique ions, isotope patterns, and potential slow vaporization associated with semi-refractory species. Here we discuss various aspects of the interaction of aerosol particles with the AMS tungsten vaporizer and the consequences for the measurement results: semi-refractory components – i.e., components that vaporize but do not flash-vaporize at the vaporizer and ionizer temperatures, like metal halides (e.g., chlorides, bromides or iodides of Al, Ba, Cd, Cu, Fe, Hg, K, Na, Pb, Sr, Zn) – can be measured semi-quantitatively despite their relatively slow vaporization from the vaporizer. Even though non-refractory components (e.g., NH4NO3 or (NH4)2SO4) vaporize quickly, under certain conditions their differences in vaporization kinetics can result in undesired biases in ion collection efficiency in thresholded measurements. Chemical reactions with oxygen from the aerosol flow can have an influence on the mass spectra for certain components (e.g., organic species). Finally, chemical reactions of the aerosol with the vaporizer surface can result in additional signals in the mass spectra (e.g., WO2Cl2-related signals from particulate Cl) and in conditioning or contamination of the vaporizer, with potential memory effects influencing the mass spectra of subsequent measurements. Laboratory experiments that investigate these particle–vaporizer interactions are presented and are discussed together with field results, showing that measurements of typical continental or urban aerosols are not significantly affected, while measurements of semi-refractory aerosol in the laboratory, close to anthropogenic sources or in marine environments, can be biased by these effects.

An Application of Spectral Kurtosis to Separate Hybrid Power Quality Events

For the development of the future smart grid, the detection of power quality events is a key issue for the power system monitoring. Voltage sags, swells, harmonics (variations) and interruptions, which produce large losses for commercial and industrial consumers, are the main events to be considered due to the sensitivity of equipment to these electrical anomalies. The steady-state events are even more frequently accompanied by transients, the discrimination and localization being far more exigent and requiring advanced signal separating tools to be incorporated in the measurement equipment. This paper shows the event detection performance of the spectral kurtosis as a signal separating tool in the frequency domain. The disturbances under test are hybrid signals resulting from the coupling between amplitude defects and non-desired higher frequencies. Being a fourth-order spectrum, the kurtosis is confirmed as a noise-resistant tool that enhances impulsiveness, therefore characterizing the electrical anomalies. In the beginning of the analysis, the voltage sag is established as a reference; then, the disturbances (oscillatory transients and harmonics) are coupled at the starting and ending instants of the sag, resulting in complex hybrid events. The results show that the spectral kurtosis enhances the detection Energies 2015, 8 9778 of both types of events (steady state and transients), which are outlined in a bump shape in the fourth-order frequency pattern and centered in the main carrier frequency. Indeed, while the oscillatory transients are associated with softer and lower-amplitude peaks, the harmonics correspond to crisper and higher ones. As these mixed electrical faults are very common in the actual power grid, the article postulates the higher-order spectra to be implemented in prospective online measurement instruments.

Towards on-line prediction of dry matter content in whole unpeeled potatoes using near-infrared spectroscopy

Prediction of dry matter content in whole potatoes is a desired capability in the processing industry. Accurate prediction of dry matter content may greatly reduce waste quantities and improve utilization of the raw material through sorting, hence also reducing the processing cost. The following study demonstrates the use of a low resolution, high speed NIR interactance instrument combined with partial least square regression for prediction of dry matter content in whole unpeeled potatoes. Three different measuring configurations were investigated: (1) off-line measurements with contact between the potato and the light collection tube; (2) off-line measurements without contact between the potato and the light collection tube; and (3) on-line measurements of the potatoes. The offline contact measurements gave a prediction performance of R2=0.89 and RMSECV=1.19. Similar prediction performance were obtained from the off-line non-contact measurements (R2=0.89, RMSECV=1.23). Significantly better (p=0.038) prediction performance (R2=0.92, RMSECV=1.06) was obtained with the on-line measuring configuration, thus showing the possibilities of using the instrument for on-line measurements. In addition it was shown that the dry matter distribution across the individual tuber could be predicted by the model obtained.

Real-Time Correction of Molecular Weight Distribution Model Based on the Field-Measurable Moments

Polymer molecular weight distribution (MWD) lacks the on-line measurement instrument. Soft sensing technology is the main method to establish its data model and give prediction on-line. The soft sensing model will be inevitably unmatched to the real process during being used in the practical industrial process. In order to improve the precision of soft sensing model, the MWD model needs to be corrected in real time or periodically. Here, the orthogonal polynomials combined neural network, i.e. soft sensing model, is used to simulate the real-time changes of MWD. Since molecular weight distribution is online un-measurable, the measurable variables, such as average molecular weight and low-order moment statistics, are used to adjust the MWD model in real time. Furthermore, these historical collected MWD data also can be used to correct this model periodically.

A Method to Study Agglomerate Breakup and Bounce During Impaction

The impaction behavior of agglomerates plays a significant role in nanoparticle technology. In order to be able to evaluate the process of de-agglomeration, the agglomerates are impacted onto a surface and forces are estimated from the breakup of the agglomerates. Several studies have used this principle; however, the simultaneous bounce and breakup of the agglomerates has received little attention. In this study, a method was devised to study both agglomerate breakup and bounce during impaction. In this method, the agglomerates were impacted onto an impaction plate located in a single stage micro-orifice uniform deposit impactor and the bounced particles were collected into a sampling chamber specially designed for this task. This way, the properties of the deposited and bounced particles can be examined with transmission electron microscopy, but in addition, the bounced particles can be analyzed with online measurement instruments, such as the scanning mobility particle sizer. Titanium dioxide (TiO2) an...

Measure dimension of rotating large hot steel shell using pulse laser on PRRR robot

During the industrial forging or rolling of hot steel shells, the raw material utilization ratio is very low because of the absence of precise on-line measurement instrument for the forging dimensions. In order to reduce the waste and increase the productivity, the pulse laser measuring instrument with dual PRRR mechanism has been developed in this study. The adjusting algorithm of rotary table based on the dual PRRR mechanism has been presented, which ensures that the scanning plane is perpendicular to the axis of cylinder shell. So the circle fitting can be adopted and the robust and accurate dimensions can be obtained rapidly by the present data-processing method. The measurement error of cold cylinder shell’s diameter is less than 3mm. The measuring results of hot steel shells are also very accurate. The present system has been used in the rolling production of large hot steel shells, which enhances the raw material utilization ratio during the rolling.

Zusammenhang zwischen luftgetragenen Partikeln und Schimmelpilzen in einem Pferdestall

The different methods of determining airborne dust concentrations are less complicated and time consuming than those for detecting microorganisms. This holds true both for gravimetric dust measurements and online measurement instruments which measure continuously. Determining the actual situation in barns by estimating the amount of aerosolized microorganisms in situ is not practicable. A statistical model was used to determine the proportion of mould spores bound to dust particles for different sized classes. The relationship between the concentration of airborne particles and mould spores is shown using a regression analysis, which can roughly predict the mould content in barns through dust measurements.

A Surface Ionization Instrument for On-Line Measurements of Alkali Metal Components in Combustion: Instrument Description and Applications

An instrument for on-line measurements of alkali components in hot flue gas streams is presented. The instrument is based on surface ionization technique and is equipped with a hot sampling line used to extract flue gas for continuous alkali measurements at pressures up to 30 bar. The instrument, its support system and the calibration procedure is described. Field campaigns with the instrument have been performed at fluidized-bed combustion facilities operating under pressurized and atmospheric conditions and using several fuels, including coal, biomass, and demolition waste. The instrument performance has been satisfactory both during pressurized circulating fluidized-bed coal combustion with alkali concentrations downstream of a hot gas filter in the ppb range, and in particle-laden conditions with alkali levels up to about 10 ppm. The measured alkali concentration corresponds to the concentration of alkali components present as vapors and fine-mode particles. In systems with high levels of fluidized-be...

An instrument for online measurement of structural orientation in translucent polymer sheets

In many applications of polymer materials, a high tensile strength is required. There is a definite correlation between the degree of orientation of molecular chains achieved in the orientation process and the tensile strength obtained. In this work, we describe design and fabrication details of a device, ‘Laser based polymer orientation grader’, for online measurement of the degree of orientation to obtain a high consistent tensile strength as output. This instrument has been designed making skilful use of the optical anisotropic property of the oriented polymer strip. The principle is based on the fact that the spatial distribution of laser light passing through the translucent polymer sheet depends on the degree of orientation of long chain molecules in the sheet. The method has potential online application in monitoring and controlling of anisotropy in manufacturing processes.

Sequential flow analysis coupled with ACSV for on-line monitoring of cobalt in the marine environment

The development of a compact instrument for on-line measurement of trace metals in seawater is described. The system is based on adsorptive cathodic stripping voltammetry (ACSV), and on the concept of sequential flow analysis, to perform on-line measurements with controlled perturbation of natural equilibria of the element. The design combines a low volume flow cell with a miniature solenoid pump and valves to achieve low power consumption. The flow segmentation is time-controlled and the detection step takes place in a well-defined part of the flow stream where reagent and sample occur mixed. The system was tested on the determination of cobalt in seawater but it is likely that the same technique can be used to determine other metals detectable by CSV. The determination range was 6–1050 pmol/L cobalt with a detection limit (3σ) of 6 pmol/L. The measurement rate was about 60 h–1. Comparative measurements were carried out using continuous flow analysis. The apparatus was used continuously on board a ship to determine the distribution pattern of cobalt in surface waters off the coast of California.

Atomic Spectrometry Update—Clinical and Biological Materials, Food and Beverages

This Update spans all the abstracts listed in the 1995 issues of JAAS (95/1–95/4243). Developments in sample preparation/enrichment continued apace. Many of these involved FI and were usually coupled directly to the analytical instrument for on-line measurements. In our recent Updates, accelerator MS for investigations of A1 physiology has been featured; this year we saw the application of the technique to Ca and other elements. The ever-present interest in lead exposure among children has prompted construction of simple, semi-portable instruments with electrothermal atomizers, dedicated to measurement of Pb in blood. These emerged at Pittcon 1995 and were also shown at later conferences. Investigations of trace element nutrition and metabolism using stable isotopes and mass spectrometric methods have been reported in the past, but this year saw the publication of a comprehensive review of this important topic. A number of papers from the Fifth Nordic Symposium on Trace Elements in Human Health and Disease were published in The Analyst, including two which described endemic arsenic toxicity in West Bengal. As the source of exposure was naturally contaminated drinking water, this tragic situation must have been ongoing for many years, and it is surprising that information has only recently been forthcoming.

Development of an instrument for on-line measurement of grain size in copper alloys and stainless steels: Diamand, R.D. NDT-86. Proceedings of the 21st annual British conference on nondestructive testing, Newcastle-upon-Tyne (United Kingdom), 16–18 Sep. 1986. pp. 225–242. Edited by J.M. Farley and P.D. Hanstead. Engineering Materials Advisory Services Ltd. (1987)

Development of an instrument for on-line measurement of grain size in copper alloys and stainless steels: Diamand, R.D. NDT-86. Proceedings of the 21st annual British conference on nondestructive testing, Newcastle-upon-Tyne (United Kingdom), 16–18 Sep. 1986. pp. 225–242. Edited by J.M. Farley and P.D. Hanstead. Engineering Materials Advisory Services Ltd. (1987)

Luminous efficiency meter for electric arcs

An instrument for on-line measurement of luminous output and luminous efficiency of a vortex-stabilised argon arc lamp has been constructed. Input power to the lamp is measured with a Hall-effect multiplier and the luminous output is measured with a visually corrected selenium cell. A commercial analogue dividing unit provides a quotient signal that is proportional to the luminous efficiency of the lamp. Two ranges of 10 and 50 lumens/watt are available in the one instrument.