On-line Probe Research Articles

Determining the linear correlation between dielectric spectroscopy and viable biomass concentration in filamentous fungal fermentations

ObjectivesDielectric spectroscopy is commonly used for online monitoring of biomass growth. It is however not utilized for biomass concentration measurements due to poor correlation with Cell Dry Weight (CDW). A calibration methodology is developed that can directly measure viable biomass concentration in a commercial filamentous process using dielectric values, without recourse to independent and challenging viability determinations.ResultsThe methodology is applied to samples from the industrial scale fermentation of a filamentous fungus, Acremonium fusidioides. By mixing fresh and heat-killed samples, linear responses were verified and sample viability could be fitted with the dielectric Delta C values and total solids concentration. The study included a total of 26 samples across 21 different cultivations, with a legacy at-line viable cell analyzer requiring 2 ml samples, and a modern on-line probe operated at-line with 2 different sample presentation volumes, one compatible with the legacy analyzer, a larger sample volume of 100 ml being compatible with calibration for on-line operation. The linear model provided an {R}^{2} value of 0.99 between Delta C and viable biomass across the sample set using either instrument. The difference in ∆C when analyzing 100 mL and 2 mL samples with an in-line probe can be adjusted by a scalar factor of 1.33 within the microbial system used in this study, preserving the linear relation with {R}^{2} of 0.97.ConclusionsIt is possible to directly estimate viable biomass concentrations utilizing dielectric spectroscopy without recourse to extensive and difficult to execute independent viability studies. The same method can be applied to calibrate different instruments to measure viable biomass concentration. Small sample volumes are appropriate as long as the sample volumes are kept consistent.

Creative Probes, Proxy Feelers, and Speculations on Interactive Skin

This paper critically discusses the combination of creative and social research methods to generate a novel approach to explore the multimodal technoscape. This paper draws on an interdisciplinary exploratory case study on interactive skin—an emergent technology that augments and/or interacts with the skin. This paper shows how concepts from skin studies and the HCI literature can be used to draw on creative methods to think about and with the body. We describe the use of an online probe pack, a speculative research workshop and sensory research interviews using ‘proxy feelers’ to agitate the design space of interactive skin futures. We show how combining these methods provoked and expanded the scope of interactive skin from the technological to the sensory and the social. We discuss the opportunities and challenges of the research dialogues that this approach facilitated, make the case for creative methodological improvisation and exploration of emergent technologies and show how creative and social research methods can be combined to explore the interconnection between technology, society and design.

Qualification of Image‐Based Measurement Systems for Characterization of Sprays

AbstractImage‐based measurement techniques become increasingly popular and expedite digitalization in chemical engineering. This article demonstrates their potential by testing two inline probes, namely modified optical multimode online probe (OMOP) and process microscope. Validations are performed with static monodisperse standards (9.2 µm to 406 µm) and fast‐moving droplets (68.6 µm to 860.7 µm; 24.5 m s−1 to 11 m s−1). Screening of a lithography attests both probes great distortion‐free image quality. A 1951 USAF chart attests a low optical resolution of 8 µm or 7 µm with respect to the OMOP or process microscope, respectively. The modified OMOP and process microscope reaches accuracies of 7.6 % or 5.9 % for particles and 8.2 % or 6.8 % for droplets.

Quantification of Entrainment Using an Optical Inline Probe

AbstractIn distillation and absorption processes, entrainment above trays or packings reduces stage and column efficiency. A modified version of the optical multimode online probe enables a seminal insight and, thus, quantification of entrained droplets on various axial and radial positions. A purging mechanism inhibits precipitation of droplets on the front lenses, while telecentric optics and illumination provide distance‐independent and precise imaging of entrained droplets between two valve trays. Experiments were performed in a DN 450 cold flow (air‐water) test rig. The results were compared with noninvasive phase Doppler anemometry data.

Online Detection of Ellipsoidal Bubbles by an Innovative Optical Approach

AbstractBubble and droplet size distribution influence chemical processes markedly. In order to enable an in‐line analysis of these distributions, a new single‐sided endoscopic version of the Optical Multimode Online Probe (OMOP) was developed. The acquired images are analyzed to gain bubble size distributions (BSDs) and main diagonals. A specific workflow was developed to detect and analyze overlapping bubbles based on standard image processing techniques. It can handle overlapping bubbles of both circular and elliptical shapes. Results confirmed that the combination of OMOP and the image processing workflow leads to robust detection of bubbles from two‐dimensional images. The new single‐sided OMOP proved to be a suitable tool for the acquisition of a BSD at industrial scale within a reasonable computing time.

Online Sensor Device for Rapid Escherichia coli Detection in Water

A novel, online probe to detect the concentration of Escherichia coli (E.coli) in water has been developed. Chronoamperometry was used to record the electrochemical current response from different E.coli concentrations based on their interaction with a locally formed catalyst on electrode surface, which occurs when a fixed potential is applied. A number of current responses that are specific to some known E.coli concentrations were recorded and used to develop a linear least squares regression model. The probe founded on this model had a detection limit of 104 CFU/ml and percent error consistently less than 15% on log scale with a detection time of 10 minutes. The major advantage of this sensor lies in its rapid detection and on-site integration, minimizing the need for continuous physical monitoring. Keywords: Electrochemical sensor; Escherichia coli detection; Online probe

Bubble size distributions with a shadowgraphic optical probe

The in-line image analysis of local bubble size distributions (BSD) in a bubble column with a diameter of 0.1 m and superficial gas velocities up to 2.1 cm/s is presented. The BSD is acquired via a telecentric shadowgraphic image analysis using a modified Optical Multimode Online Probe (OMOP). The column is operated in batch mode by using different alcohol/water mixtures aerated with compressed air, purged through a sintered glass plate (dp= 100–160 µm). At a total holdup up to 35%, the specific surface area is calculated out of the BSD by the optical method and compared to an empirical correlation.

Abstract A024: Probe Miner: objective, quantitative, data-driven assessment of chemical probes for target validation

Abstract Chemical probes are important, widely used reagents for understanding biologic systems and for target validation. However, selection of chemical probes is largely subjective and prone to historical and commercial biases. Despite many publications discussing the aspirational properties of chemical probes and the proposal of "fitness factors" to be considered when assessing chemical tools, scientists often select probes through web-based searchers or previous literature that are heavily biased towards older and often flawed probes or use vendor catalogues that do not discriminate between probes. Here, we analyze the scope and quality of published bioactive molecules and uncover large biases and limitations of chemical tools in public databases that need to be urgently addressed and should be always considered when using chemical tools. We also provide the online Probe Miner resource (http://probeminer.icr.ac.uk) capitalizing on the plethora of public pharmacologic data to enable quantitative, unbiased, objective, Big Data-driven assessment of chemical probes and complement expert-curated approaches. We assess >1.8m compounds for their suitability as chemical tools against 2,220 human targets, demonstrating that large-scale public data can contribute to improving chemical probe assessment and prioritization to empower researchers in the selection of chemical tools for biomedical research and target validation. Citation Format: Albert A. Antolin, Joe E. Tym, Angeliki Komianou, Ian Collins, Paul Workman, Bissan Al-Lazikani. Probe Miner: objective, quantitative, data-driven assessment of chemical probes for target validation [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A024.

Cognitive bias modification for social anxiety in adults who stutter: a feasibility study of a randomised controlled trial

ObjectiveTo determine the feasibility and acceptability of a computerised treatment for social anxiety disorder for adults who stutter including identification of recruitment, retention and completion rates, large cost drivers and...

Measuring Situation Awareness of Student Air Traffic Controllers with Online Probe Queries: Are We Asking the Right Questions?

ABSTRACTSituation awareness (SA) is a major factor determining operator performance in the current and future airspace systems, so it is not surprising that a considerable body of research on measuring operator SA has been amassed. A commonly used SA measurement method is a probe technique in which the operator is queried about the current state of his/her task environment, either offline (while a computer simulation is paused) or online (while a computer simulation is running.) Although sufficient evidence for the reliability and validity of both techniques is available, one factor that has not been systematically investigated is the efficacy of the questions themselves. We evaluated the types of online probe questions used for predicting the performance of student air traffic controllers in a simulated air traffic management task. These data were obtained from 84 students who completed a 16-week radar internship course in which their situation awareness and performance were assessed at the midpoint and end of the course. We subjected probe question latencies to a principle component analysis (PCA) to explore the variation between questions and grouped them based on the resulting components. The SA question components that emerged from PCA were then used to model the relations between SA factors and performance. The resulting model provides a framework for understanding factors involved in SA, a way to evaluate the validity of individual probe questions as a measure of SA, and a method for determining the efficacy of SA questions in predicting operator performance.

Mid‐Infrared Spectroscopy for Monitoring of Anaerobic Digestion Processes – Prospects and Challenges

AbstractTo develop an online probe that is not only sufficiently robust, but also able to measure crucial process variables in biogas plants is a tough challenge. Therefore, a mid‐infrared (MIR) spectroscopic attenuated total reflection (ATR) probe and robust probe fitting were established. A fully automated probe control, calibration after probe cleaning, and analysis of the absorption spectra using machine learning were implemented in order to reduce maintenance of the probe to a minimum. The relevant wavelengths in the MIR spectrum for organic acids, total alkalinity, and ammonium nitrogen concentration were identified. Finally, intensive lab testing was carried out, followed by operation of the complete online measurement system at an industrial biogas plant. In order to improve signal strength and sensitivity, microelectronic mechanical system (MEMS)‐based Fabry‐Pérot interferometers were also investigated.

A Comparison of Methods for Assessing Situation Awareness in Current Day and Future Air Traffic Management Operations: Graphics-Based vs Text-Based Online Probe Systems

Abstract: Operator situation awareness can be measured by examining operator response time and accuracy to online queries or probes. We compared an existing, text-based query method with a new graphics-based method. The text-based method presented multiple-choice queries to air traffic controllers (ATCos) on a display next to the DSR. Responses were entered by selecting one of the response alternatives presented with the query. The graphics-based method presented the query along with a screen shot of ATCo’s current traffic on the DSR. The ATCo responded by touching the symbol of the aircraft that was the subject of the question. These methods were compared in a simulation involving student ATCos currently enrolled in an Aviation Sciences program.

Measuring Situation Awareness with Probe Questions: Reasons for not Answering the Probes

Situation Awareness (SA) refers to an individual's understanding of what is happening in their environment, and what is likely to happen in the near future [1]. SA is an important construct to study in aviation because lower levels of SA are associated with increased aviation accidents and mishaps [2]. One technique to measure operator SA is through the use of online probe questions, where operators are queried about their task environment at various intervals while performing the task. The current study used the Situation Present Assessment Method (SPAM) [3] for administering online probes. With SPAM, a ready prompt appears on a panel and participants are instructed to accept the prompt when workload permits to be presented with a SA probe question. Latencies in accepting the ready prompt are indicative of the operator's workload level at that time. When ready prompts go unanswered, (ready time-outs; RTO), it is assumed workload is too high. When a prompt is accepted, probe questions are presented for a limited time (60seconds in this study). Thus it is possible they too will go unanswered by timing out (question time-out; QTO). QTOs can occur for the following reasons: 1) operator did not know the answer, 2) due to the dynamic changes in the task, the operator workload became too high to devote resources to answering the question, 3) question was unanswerable due to the current context, or 4) question required more time to answer than allowed. In the present study, we analyzed a subset of the data from a larger study (see Brandt et al. [4]) to examine reasons for why probe questions go unanswered. For QTOs, the majority of questions went unanswered because the operator did not know how to answer the question, or because the operator was dealing with high workload. RTOs, which occurred more frequently, were normally due to task/workload.

Real Time Validation of Online Situation Awareness Questionnaires in Simulated Approach Air Traffic Control

Measuring Situation Awareness (SAw) to evaluate an operator's ability to handle complex dynamic situations and the use of assistance systems have become a standard approach in Human Factors research. Ideally, the operators should be supported by enabling and disabling assistance systems depending on their SAw. On the one hand, if the situation's complexity increases and therefore SAw is likely to be reduced, additional systems may help to prevent overextension by taking control over the specific task or task components. On the other hand, there has been evidence that high levels of automation may reduce the ability to intervene in a timely manner if needed due to mental underload. Adjusting the usage of assistance systems based on the operator's SAw may help to overcome both limitations. However, existing measurement tools for SAw require post-simulation analysis. This way it is not possible to make decisions based on the operator's SAw in parallel with the situation at hand. Software capable of analyzing the current state of a given situation has been developed to allow real time assessment of SAw. This software was designed to measure SAw of approach air traffic controllers in the real time NLR ATM Research Simulator. SAw was measured by presenting questionnaires during three different scenarios. Before an item was presented, the simulation's log files were analyzed to provide the software with the correct answer. This way, validating responses and evaluating SAw immediately was possible. In a first study, 57 non-expert subjects were presented with online probe questionnaires in real time simulated approach air traffic control scenarios. It was found that the software was able to measure SAw in real time. In the future, such systems could be used to make decisions about the need for further assistance while the situation is still happening. This way, operators would only get the necessary amount of assistance without reducing their work to passive monitoring.

Investigating hydrological drivers of nitrate export dynamics in two agricultural catchments in Germany using high-frequency data series

In this study near-continuous time series of nitrate, electrical conductivity, and discharge were used to identify the dominating hydrological mechanisms that control nitrate export dynamics in two agricultural catchments. The main goal was to assess relationships between contrasting event based as well as long-term nitrate transport behaviour and catchment hydrology. Data records were obtained from online probes that allow field based high-frequency analyses over long time periods. The catchments of the Ammer River (southwestern Germany) and the Weida River (eastern Germany) are similar with respect to size (~100 km²), morphology, and climate and are dominated by agricultural use. Main differences are the stronger urbanization and the occurrence of karstic rocks in the Ammer catchment. Nitrate concentrations are high in water of both streams and range mostly between 20 and 50 mg l−1. Nitrate export in the Ammer catchment is dominated by baseflow and a minor second, diluting runoff component generated in urbanized areas. In contrast, nitrate dynamics of the Weida catchment is governed by the interplay of at least three runoff components, while the largest amount of nitrate is mobilized intermittently by a delayed fast component generated in the catchment’s soils during wet conditions. These interpretations, derived with one online probe at the outlet of each catchment, are well in line with the former modeling results. This study shows that high-resolution data obtained by online techniques offers a large potential to improve the conceptualization of dominating flow and transport processes at catchment scales at relatively low costs and effort.

Drop swarm analysis in dispersions with incident-light and transmitted-light illumination

The new developed Optical Multimode Online Probe (OMOP) can process images from either incident-light illumination (also called epi-illumination) or transmitted-light illumination (also called trans-illumination). The probe has an outer diameter of 38mm and the illumination is achieved by high performance Light Emitting Diodes (LEDs) with specifications of 1.96mm² and 493lm (251.53lm/mm²) at an angular deviation of 0.37°. A camera probe is used with either an object-space telecentric (telecentricity <0.2°, 2437mm virtual pupil distance) or entocentric objective (Köhler based illumination, 6238mm virtual pupil distance). Using the telecentric mode, the particle distance independency is located within 20mm while the focal depth is approximately 5mm. The local resolution is between 20 and 30μm, according to the used optics, with a standard deviation less than 4.5%. Maximum particle diameter is up to 5mm while particles can reach up to 2m/s as function of exposure. The basic distance transform approach with watershed segmentation for analysis of transmitted-light images gives deviations less than 5% at high particle densities and less than 2% at low ones. The error of false positives typically is below 5% while the error of wrong radiuses is below 1% for up to 90% of all droplets and below 5% otherwise. Up to five images per core and second (trans-illumination) can be analyzed automatically and online at densities up to 25% (trans-illumination, gap width less than 5mm) 40% (object side telecentric epi-illumination, single probe) respectively.The advanced pre-segmentation approach based on the Random Forest Classifier (RFC) is used to perform the more complex image analysis with epi-illumination. As long as the quality of pre-segmentation is high enough, the classification results in images, which can be analyzed in the following distance transform approach. This is considerably depending on the quality of training the algorithm and recurring image features. Compared to the distance transform analysis at low densities the deviation increases. The RFC pre-segmented image gives an additional deviation of 1.1% (both in regard to the total amount of evaluated pixels) and a deviation of 12.9% in regard to the mean particle diameter. Below a particle size of 50 pixels the image analysis overestimates the actual number of particles due to the sensitivity of the Euclidian distance approach.

Measuring the Impact of NextGen Operating Concepts for Separation Assurance on Pilot Situation Awareness and Workload

We determined the effect of NextGen concepts of operation for separation assurance on pilot situation awareness and workload using an online probe technique. We also evaluated the probe technique for sensitivity, diagnosticity, and validity with respect to different NextGen separation assurance operating concepts. These concepts allocated responsibility for conflict detection and resolution to either pilots, air traffic controllers, or an automated, ground-based, conflict detection and resolution agent. Probe queries were developed to fit in 1 of 3 categories: traffic conflicts, aircraft or airspace status, or commands and communications. We determined that pilot situation awareness of conflict information was highest when the pilot was responsible for separation assurance; workload was minimally affected. Moreover, the changes in pilot awareness of task-specific information can be determined using this online probe technique. Evidence for the reliability and validity of our probe technique is also provided.

Study of Travel Time Prediction by Using Online ATIS and Probe Vehicle in Beijing

With the rapid development of urban traffic, travel time had become the crucial factor for road-user to make decisions on means of transportation, path finding. Besides, emerging information technology, such as Traffic information technology, GIS (Geographic Information System) technology and etc, that have promoted the tendency that people are inclining to plan personal travel through Dynamic Route Guidance System characterized as travel time prediction according to real-time traffic data. In this paper, it first proposed the factors of selecting the test O-D (original-destination), which travel time will be predicted by GoogleMap, BaiduMap, SogouMap and SOSOMap, for comparison, probe vehicle would run along the route provided by those online ATIS (advanced traveler information system) to check the accuracy of travel time predicted. Finally, it analyzes and assesses the service of travel time prediction of such systems.

A Path Planning Model Based on Point Structure in On-Line Reverse System

The reverse engineering general with coordinate measuring machine or 3D scanner realize the parts digital，and the measuring equipment is very expensive which limit the reverse engineering application. To solve this problem, this paper uses the higher precision walking mechanism of numerical control machine, adds the special online probe to compose a digital measuring equipment ；it uses the CAD sketch model to drive, which researches the basic representation method of the path information，the distribution form of the measuring point in the different characteristic element，the distinction between the measuring point，the attribution rules and the derived form of the path information of the measuring point. It also includes the development of dedicated reverse soft and the automatic generation of the measuring program reverser path. This method provide a new low cost reverse engineering means which decrease measured data and simplify the reverse engineering.

Estimation of nitrate reductase enzyme parameters in activated sludge using an extended Kalman filter algorithm

This paper demonstrates an application of the extended Kalman filter to a wastewater plant using real process data to estimate parameters in a semi-mechanistic model. This technique for parameter identification allows a semi-mechanistic model developed for pure cultures to be applied to a mixed culture population where isolation of enzyme kinetic parameters is not practical. This paper demonstrates an application in which a wastewater treatment facility with three physical unit operations and an unusual operating profile is modeled as 11 reactor units with recirculation streams. On-line nutrient probe data from two locations in the aerobic reactor are combined with operational data for flows and feed composition. This paper demonstrates the successful application of a biochemical model developed at the bench scale to this facility through the use of an extended Kalman filter. The estimated biological model parameters and the covariance matrix diagonal converge to stable values, indicating a successful implementation.