Controlled Laboratory Setup Research Articles

Influence of Lead Pollution on Cohesive Soil Erodibility using Jet Erosion Tests

<p class="1Body">Recent researches were investigated the high concentrations of Lead in Baghdad soils due to the emissions from Leaded fuel of cars, generators, and the industrials. These high concentrations in addition to their impact on human health may impact on the landscape and streambanks and may cause significant issues on soil erodibility. The erosion rate of cohesive soil was usually estimated using two alternative models, excess shear stress model which is depended on two major soil parameters: the critical shear stress, <em>τ<sub>c</sub></em>, and the erodibility coefficient, <em>k<sub>d</sub></em>, and Wilson model which is depended on two mechanistic soil parameters: <em>b<sub>0</sub></em> and <em>b<sub>1</sub></em>. A new miniature version of Jet Erosion Test (“mini” JET) was performed to derive both model parameters. The objective of this study was to investigate the influence of Lead pollution on cohesive soil erodibility using “mini” JET under controlled laboratory setups to predict soil erodibility. In order to observe the Lead contamination on soil erodibility, soil samples were mixed with different quantities of Lead concertation and the samples were packed at ASTM standard mold on two different bulk densities. Results show that the Lead pollution increased soil erodibility when the concentration of Lead increased. An inverse relationship between excess shear stress parameters <em>k<sub>d</sub></em> and <em>τ<sub>c</sub></em> was observed as well as between Wilson model parameters <em>b<sub>0</sub></em> and <em>b<sub>1</sub></em>. The Wilson model parameters were closely resembled the empirical excess shear stress parameters with benefit that Wilson model parameters are mechanistic parameters.</p>

Demonstration of temperature imaging by H_2O absorption spectroscopy using compressed sensing tomography

This paper introduces temperature imaging by total-variation-based compressed sensing (CS) tomography of H2O vapor absorption spectroscopy. A controlled laboratory setup is used to generate a constant two-dimensional temperature distribution in air (a roughly Gaussian temperature profile with a central temperature of 677 K). A wavelength-tunable laser beam is directed through the known distribution; the beam is translated and rotated using motorized stages to acquire complete absorption spectra in the 1330-1365 nm range at each of 64 beam locations and 60 view angles. Temperature reconstructions are compared to independent thermocouple measurements. Although the distribution studied is approximately axisymmetric, axisymmetry is not assumed and simulations show similar performance for arbitrary temperature distributions. We study the measurement error as a function of number of beams and view angles used in reconstruction to gauge the potential for application of CS in practical test articles where optical access is limited.

Application of learning algorithms for colour recognition on underwater images

AbstractObjects look very different in the underwater environment compared to their appearance in sunlight. High quality images with correct colouring simplify the detection of underwater objects. Hence, image processing is required to obtain images of high quality and correct colouring. Current algorithms focus on the colour reconstruction of scenery at diving depth where a significant part of sunlight is still present and different colours can still be distinguished. At greater depth the filtering is much stronger such that this is not possible. In this study it is investigated whether machine learning can be used to transform image data obtained in a controlled laboratory setup. The images are fed through learning machines with or without pre‐filters. It is shown that k‐nearest neighbour and support vector machines are most suitable for the given task and yield excellent results. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Do Personality Traits Affect Productivity? Evidence from the Lab

While survey data supports a strong relationship between personality and labor market outcomes, the exact mechanisms behind this association remain unexplored. In this paper, we take advantage of a controlled laboratory set-up to test whether this relationship operates through productivity, and isolate this mechanism from other channels such as bargaining ability or self-selection into jobs. Using a gender neutral real-effort task, we analyse the impact of the Big Five personality traits on performance. We find that more neurotic subjects perform worse, and that more conscientious individuals perform better. These findings are in line with previous survey studies and suggest that at least part of the effect of personality on labor market outcomes operates through productivity. In addition, we find evidence that gender and university major affect the impact of the Big Five personality traits on performance.

A New Wheelchair Ergometer Designed as an Admittance-Controlled Haptic Robot

Wheelchair ergometers aim to simulate the propulsion of a wheelchair in a controlled laboratory setup. One drawback of current ergometers is that the simulated wheelchair is always modeled as a simple unidimensional mass and friction, which do not allow a correct simulation of turning maneuvers. In this paper, we present a new design for a wheelchair ergometer based on haptic robotics. This ergometer allows us to simulate any linear or nonlinear model of the wheelchair-user system in real time, including models that implement turning maneuvers. The presented prototype was validated experimentally. The rear wheels of the ergometer match the rear wheels' velocities of the simulated wheelchair with a root-mean-square error of 0.9 %. Therefore, the ergometer's accuracy is mainly bounded by the accuracy of the wheelchair-user model, which means that future improvements of the wheelchair-user model will be directly reflected by the ergometer. The conditions for stability were also evaluated. A minimal simulated mass of 18 kg and a minimal simulated moment of inertia of 1 kg ·m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> are needed. These requirements are encountered by any wheelchair-user combination.

An assessment of distance learning laboratory objectives for control engineering education

ABSTRACTThe concept of web laboratories with remotely controlled laboratory set ups or virtual laboratories with different simulations have an important role in engineering education and training. This paper presents an evaluation of the fundamental objectives of laboratories for distance education, comparing the effectiveness of a remotely controlled approach versus simulations. The results and analysis show that students prefer remotely controlled laboratories compared to simulation labs. The results show that remotely controlled laboratories better fulfill objectives important for laboratory exercises. © 2013 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:191–202, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21589

The objectives, architectures and effects of distance learning laboratories for industrial engineering education

The concept of laboratories for distance (e-learning) with remotely controlled laboratory set-ups or virtual laboratories with different simulations have an important role in industrial engineering education and training. Although the concept is not new, there are a number of open issues that should be solved. This paper will present the fundamental objectives of learning through distance learning laboratories as well as the special issues connected with these labs, including their effectiveness. Other important questions will be addressed such as pre requests for remote controlled/virtual labs according to different stakeholders, different architectures will be compared and, finally, evaluations and students' feedback will be presented.

Landmark‐based augmented reality system for paranasal and transnasal endoscopic surgeries

In this paper we present a landmark-based augmented reality (AR) endoscope system for endoscopic paranasal and transnasal surgeries along with fast and automatic calibration and registration procedures for the endoscope. Preoperatively the surgeon selects natural landmarks or can define new landmarks in CT volume. These landmarks are overlaid, after proper registration of preoperative CT to the patient, on the endoscopic video stream. The specified name of the landmark, along with selected colour and its distance from the endoscope tip, is also augmented. The endoscope optics are calibrated and registered by fast and automatic methods. Accuracy of the system is evaluated in a metallic grid and cadaver set-up. Root mean square (RMS) error of the system is 0.8 mm in a controlled laboratory set-up (metallic grid) and was 2.25 mm during cadaver studies. A novel landmark-based AR endoscope system is implemented and its accuracy is evaluated. Augmented landmarks will help the surgeon to orientate and navigate the surgical field. Studies prove the capability of the system for the proposed application. Further clinical studies are planned in near future.

Validation and pilot clinical study of a new bronchoscopic method to measure collateral ventilation before endobronchial lung volume reduction

Endobronchial lung volume reduction (ELVR) may be helpful in a selected group of patients with advanced stages of emphysema. However, collateral ventilation (CV) from adjacent lobes through collateral channels often prevents target lobe atelectasis, which presumably mediates clinical responses after ELVR. With the goal of identifying patients who are more or less likely to benefit, we propose endobronchial CV assessment (ECVA), a novel catheter-based endobronchial approach, to quantitatively determine the resistance of collateral channels (R(coll)). ECVA relies on the measurement of spontaneous airflow from the sealed and isolated target compartment during spontaneous respiration in an awake subject, thereby providing a direct, simple, and minimally invasive method of assessing R(coll) in lungs. In this study, we validated ECVA in a controlled laboratory setup and tested ECVA's clinical feasibility in 11 emphysematous human subjects undergoing ELVR treatment. To evaluate ECVA in a controlled laboratory setup with known CV levels, we built a benchtop model mimicking a simple one-compartment model of the lungs during temporary compartmental occlusion and spontaneous respiration, which could be adapted to hold restrictors of different sizes representing collateral airways, and applied ECVA to estimate the resistance of various benchtop model restrictors. We then rated ECVA's performance by direct comparison between estimated and actual restrictor resistance and found a correlation coefficient near one. To test ECVA's clinical performance, post-ELVR radiological assessments were made to determine the occurrence of atelectasis in the treated lobe, and interlobar R(coll) was estimated in the target lobe via ECVA pre-ELVR. ECVA could be completed in all patients with no adverse events, and a high R(coll) by ECVA predicted absorption atelectasis following ELVR ( P = 0.005). We believe that ECVA may be helpful to distinguish those patients with and without interlobar CV by identifying the critical value of R(coll) above which atelectasis is likely to occur.

Hand-Assembled Cable Bundle Modeling for Crosstalk and Common-Mode Radiation Prediction

A statistical cable bundle model is developed to account for the random disturbance of the wire positions along hand-assembled cable bundles. The nonuniform random bundles are modeled as n-cascaded segments of a uniform multiconductor transmission line. At each section, all wire positions are disturbed with random numbers obeying a Gaussian distribution. In addition, a spline interpolation function is used to improve the continuity of wires winding along the bundle. The wire crosstalk and the common-mode (CM) current distribution along the bundle can be calculated with simulation program with integrated circuit emphasis (SPICE)-like solvers. By injecting the CM current along the bundle into a full-wave tool, e.g., finite-difference time domain (FDTD), as impressed current sources, the system-level electromagnetic emissions from the cable bundles can be predicted. The model has been experimentally validated with a controlled laboratory setup.

Spermatogenesis of Bathymodiolus azoricus in captivity matching reproductive behaviour at deep-sea hydrothermal vents

This study aims to improve our knowledge on the reproduction cycles of invertebrates from deep-sea hydrothermal vents, which is fragmentary to date, owing to the prohibitive costs of regular time series sampling required for a complete assessment. However, new technologies such as acoustically retrievable cages and the long-term laboratory maintenance of vent species enabled sampling at relatively low costs. Reproductive patterns of the vent bivalve Bathymodiolus azoricus were studied with regard to the onset of spermatogenesis in captivity as compared to specimens from the wild. Following 1-year in our controlled laboratory set-up, spermatogenesis started in January–February, as “naturally occurs” in mussels at hydrothermal vents, which provide further supporting evidence for an annual reproduction in B. azoricus. In addition, we describe a functional methane-feeding system for the long-term maintenance of the hydrothermal mussel that represents great potential for post-capture experimental investigations.

Microprocessor Controlled Inclined Etching for the Measurement of Carrier Concentration Profile

The paper deals with the presentation of microprocessor controlled laboratory setup for the inclined etching of substrate to measure the carrier concentration depth profile of a sample. The laboratory setup used here is a microprocessor controlled linearly graded etchant level system. The precised slope of etched surface is obtained by sliding the piston in syringe containing etchant at particular rate using microprocessor. The results are compared with that obtained without any flow controlling arrangement. Schottky contacts are then made on the sloppy surface to measure the carrier concentration against the depth by the conventional C-V method. Our developed techniques are very accurate and inexpensive as compared to the conventional commercially available systems. The developed technique has potential applications in the fabrication of several optoelectronic devices such has vertical waveguide splitters, couplers, microlences, reflectors, prisms etc.

Strain Rate Effects in Model Pressuremeter Testing

A series of one-eighth-scale strain controlled model pressuremeter tests were performed using an automated flexible wall calibration chamber testing system. Undrained model pressuremeter tests were performed with and without the internal pore-water pressure measuring piezometer needles at radial strain rates ranging from 1 to 8%/min in a controlled laboratory setup in beds of kaolin clay prepared with known stress histories. Reference strength and deformation properties were determined using one-dimensional consolidation, isotropically consolidated undrained compression, and K(sub 0) consolidated undrained compression laboratory tests; and comparisons were made with the interpreted values from the pressuremeter test data. Interpretations of the undrained shear strength, initial shear modulus, shear stress-radial strain variation, limit pressure, and horizontal stress for each net pressuremeter curve were evaluated via various interpretation procedures, using the Marquardt-Levenberg algorithm. Based on the laboratory test data and the analytical interpretations, several conclusions were made regarding the effects of the rate of probe expansion on the deduced shear modulus, undrained shear strength, and limit pressure in the pressuremeter testing of clays.