Simple Inline Research Articles

Affordable inline structuration measurements of printable mortar with a pocket shear vane

The control of mortar rheology is of paramount importance in 3D printing concrete by extrusion. This is particularly sensitive for two-component (2K) processes that use an accelerator to switch the printed mortar very quickly from a liquid behavior to a sufficiently solid behavior to be able to be printed (i.e. structuration). After some main key points about measuring the structuration of printed mortars, we propose an original and simple inline test using a pocket shear vane tester. The test is able to measure over several decades of yield stress range, mobilizes small quantities of mortar and enables in-situ measurements on freshly printed layers. The results highlight the difference of structuration between a benchtop-prepared printable material and a truly printed material, fostering the importance of inline measurements, and demonstrating the quality of the method. This pocket shear vane test appears as good contender for a light and affordable rheometer for 2K printable mortars.

A 3-D Printed Ku-Band Waveguide Filter Based on Novel Rotary Coupling Structure

A Ku-band (12–18 GHz) waveguide bandpass filter has been designed, fabricated using stereolithography (SLA) printing, measured, and presented. The filter is composed of five coupled TE101 resonators, where the external/internal couplings are implemented through the rotation of resonators. This novel filter structure is superior to conventional filters based on irises, in terms of reduced sensitivity to fabrication inaccuracies (i.e., allowing larger tolerance in the fabrication process), as the coupling strength depends on the mutual rotation angle between resonators and input/output waveguides. This simple inline filter structure also allows the generation of transmission zero (TZ), by altering the rotation angles of resonators. A Ku-band prototype filter, with a center frequency of 14 GHz, a bandwidth of 0.8 GHz, a return loss of 20 dB, and a TZ at 14.8 GHz, has been successfully demonstrated, and this verifies the proposed concept.

Rectangular top-hinged plate as portable flow measuring device

Abstract Most previous studies have focused on adjustable complex flap gates and little research has been carried out on simple inline top-hinged plates for flow measurement. The present study investigates discharge measurement by top-hinged plates located along channels under free flow condition. The proposed simple device is a portable one. Two discharge models are proposed based on Buckingham's theorem of dimensional analysis. The first model (Model I) considers deflection angle as an independent variable while the second model (Model II) considers it as a dependent variable. A series of laboratory experiments (687 runs) were performed to calibrate the proposed models. The results showed that when the slope of the channel increases, the accuracy of the proposed model slightly decreases. The first model has an average error of 2.32%, while the second model has an average error of 3.19%, thus flow discharge through the rectangular channels with longitudinal slopes in range of [0, 0.005] can be accurately estimated using the proposed discharge models. Based on this experimental study, the plate length enhances the performance of the second model when the mass plate is unknown. The proposed device offers a simple and reliable discharge measurement approach for both horizontal and sloping rectangular channels.

Inline holographic inscription of diffractive lenses in azobenzene molecular glass thin films.

A simple inline holographic setup is used to fabricate holographic diffractive lenses using off-the-shelf components. The resulting surface relief gratings are inscribed directly in azobenzene-functionalized thin films with pitches that agree well with a theoretical Fresnel zone plate. The annular gratings have an outer radius of approximately 9 mm and an inner radius of less than 4 mm. Interfering laser beams, circularly polarized in the same direction, generally produce poor-quality gratings in azo-films, but the addition of a reference beam lens greatly improved their consistency and produced quality gratings with depths up to 400 nm. Multiple exposures produce multifocal diffractive lenses, while angling the sample resulted in focal lines, instead of focal points.

Inline holographic microscopy through fiber imaging bundles.

Fiber imaging bundles are widely used as thin, passive image conduits for miniaturized and endoscopic microscopy, particularly for confocal fluorescence imaging. Holographic microscopy through fiber bundles is more challenging; phase conjugation approaches are complex and require extensive calibration. This paper describes how simple inline holographic microscopy can be performed through an imaging bundle using a partially coherent illumination source from a multimode fiber. The sample is imaged in transmission, with the intensity hologram sampled by the bundle and transmitted to a remote camera. The hologram can then be numerically refocused for volumetric imaging, achieving a resolution of approximately 6 µm over a depth range of 1 mm. The scheme does not require any complex prior calibration and hence is insensitive to bending.

Realization of Multiple Transmission Zeroes for Bandpass Filters With Simple Inline Topology

The realization method of multiple transmission zeroes (TZs) for second-order bandpass filters (BPFs) is presented in this brief. A modified filter topology with mixed couplings is investigated at first. With the cancelation effect of electric and dominant magnetic couplings, two close-to-passband TZs can be easily realized for a second-order inline filter. Furthermore, the dual-function feature of loaded quarter-wavelength ( $\lambda $ /4) resonators is analyzed. Besides of filtering response, $\lambda $ /4 resonators can be used to realize two more TZs in the stopband. At last, multiple open stubs are loaded asymmetrically at feeding lines, each of which can generate one TZ independently. Due to the asymmetric loading, the extra circuit area of bandstop structures is reduced by half. For demonstration, a wideband BPF using $\lambda $ /4 resonators and four asymmetric open stubs is designed, fabricated, and measured. The stopband suppression can be improved to 10.2 GHz without sacrificing in-band properties or enlarging circuit size. Good agreement can be observed between the measured and simulated results of the proposed BPF.

Inline flow sensor for ventriculoperitoneal shunts: Experimental evaluation in swine

Shunts are commonly employed to treat hydrocephalus, a severe central nervous disease caused by the buildup of cerebrospinal fluid in the brain. These shunts divert excessive cerebrospinal fluid from brain ventricles to other body cavities, thereby relieving the symptoms. However, these shunts are highly prone to failure due to obstruction from cellular debris, leading to cerebrospinal fluid accumulation in the brain and exacerbation of neurological symptoms. Therefore, there is a clinical need for a reliable, non-invasive method of monitoring shunt performance. Recently, a simple inline flow sensor was reported for monitoring ventriculoperitoneal shunting of cerebrospinal fluid in hydrocephalus treatment. The present work aimed to evaluate performance of the device in an animal model of hydrocephalus. Sensor-equipped shunt tubes were placed in anesthetized, juvenile swine. The flows reported by the sensor were compared with gravimetric flow measurements. Robust correlations (r ≈ 0.87–0.96) between the gravimetric and sensor-reported flows were obtained in 4 of the 6 experiments. The mean slope of the linear relationship of the gravimetrically determined vs. sensor flow rates was 0.98 ± 0.09 in the 6 experiments, indicating the sensor accurately reported shunt flows up to 35 ml/h. The sensor responded immediately to abrupt flow changes following cerebroventricular fluid injections. Minor hardware problems were identified and corrected. These experiments provide practical guidance for future preclinical testing of the device.

Dumbbell shaped inline Mach–Zehnder interferometer for glucose detection

A simple inline Mach Zehnder Interferometer (MZI) with a dumbbell-shaped structure is developed for measuring glucose concentration in distilled water. The MZI is fabricated using an arcing function of a fusion splicer. The sensor consists of two bulges separated by a tapered waist. The MZI generates a good reflected interference spectrum where the dip wavelength is red-shifted with the increase of glucose concentration. This is due to the increase of the surrounding refractive index, which reduces the phase difference between the core and cladding modes. As the glucose concentration increases from 0% to 12%, the dip wavelength increases from 1554.419 to 1554.939nm in a quadratic manner with the coefficient of determination of 0.9818. It is also found that the sensor has a sensitivity of 0.04nm/% with a linearity of 96.7%. The limit of detection is 4.5%. This preliminary result shows that the proposed probe can be used as a sensor to detect glucose concentration in distilled water.

High sensitive fiber-optic liquid refractive index tip sensor based on a simple inline hollow glass micro-sphere

Abstract A high sensitive fiber-optic refractive index tip sensor based on a simple inline hollow glass micro-sphere is presented. The inline hollow glass micro-sphere can be automatically constructed at the splicing joint break time when splicing a hollow core photonic crystal fiber to an SMF. Simultaneously, the micro-sphere is tipped on the SMF end. It is temperature insensitive in the air due to its micro size and hollow cavity sphere structure. The ambient refractive index can be measured by detecting the extinction ratio variation of the sensor, with a high sensitivity.

MS2 removal from high NOM content surface water by coagulation ‐ ceramic microfiltration, for potable water production

AbstractMS2 bacteriophages removal from surface water, characterized by high natural organic matter (NOM) content, was investigated by inline coagulation/flocculation pretreatment followed by ceramic microfiltration (MF). MS2 and DOC removal increased with lower pH and higher coagulant dose. Lowering the coagulant pH from 6.5 to 5.5 for polyaluminum chloride (PACl), and to 5.0 for iron chloride (FeCl), respectively, along with doubling of the coagulant dose from 2 to 4 mg Al/L, and from 4 to 8 mg Fe/L, respectively, maximized the virus removal, resulting in more than six log unit reductions up to complete virus retention. However, high residual metal concentrations were found under such conditions. Comparison of conventional two‐stage coagulation pretreatment with simple inline coagulation did not show any significant performance differences. Both investigated coagulants showed virus inactivation about two log units after 60 min contact time, which is equivalent to a virus inactivation of 99%. This inactivation was only reversible to a small extend by chemical or physical floc destruction. The investigated process combination can comply with modern hygienic barrier standards. © 2011 American Institute of Chemical Engineers AIChE J, 2012

Surface passivation of phosphorus-diffused emitters by inline thermal oxidation

Abstract We show that inline thermal oxidation is a very promising alternative to the use of conventional batch type quartz tube furnaces for the passivation of industrial phosphorus-diffused emitters. Our results reveal that both inline and batch oxidation allow similar results for oxide layer thickness, sheet resistance and, most important, emitter dark saturation current density J 0e even when compressed dry air is used as a cost effective oxygen source. Using a ~10 nm thin thermal oxide layer and a SiN x antireflection coating of adapted thickness, we achieve J 0e values as low as ~100 fA/cm² (68 Ω/sq., textured surface). Using a simple inline oxidation process in air ambient, solar cells with a conventional Al-BSF rear side and a thermal SiO 2 /SiN x passivated front yield average efficiencies of 18.1%, demonstrating 0.3% absolute efficiency gain compared to solely SiN x passivated emitter references. © 2010 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of SiliconPV.

In Situ Detection of Altered Particle Size Distributions during Simulated Powdered Sorbent Injection for Mercury Emissions Control

During full-scale sorbent injection tests for mercury removal at coal-fired power plants (CFPPs), a common trend has been observed in which the overall mercury removal efficiency reaches a performance plateau as the sorbent injection rate increases. Two common explanations for this trend are (1) the increased sorbent injection rate induces increased rates of particle agglomeration within sorbent feeding lines, which eventually shifts the particle size distribution to larger sizes and reduces the available particle surface area for heterogeneous oxidation and adsorption, and (2) the increased sorbent injection rate limits the available acid gas concentration for heterogeneous oxidation of Hg0 to Hg2+. In this experimental study, an in situ measurement technique based on the principles of light extinction is used to assess the degree of particle agglomeration. The present in situ measurement technique applies a simple inline HeNe laser, and a sorbent feeder fluidizes powdered activated carbon (PAC) and drives the suspension through a length of rubber tubing to simulate the sorbent feeding process. Each experimental trial yields a time-dependent function of the light extinction ratio, I(t)/I0, for the time-dependent evolution of the PAC suspensions. Observed differences in I(t)/I0 for suspensions ejected directly from the feeder as compared to those directed through the tubing indicate changes in the overall particle size distribution. A numerical model of the experiment provides excellent agreement and facilitates interpretation of the experimental results.

An Automated Statistical Process Control Study of Inline Mixing Using Spectrophotometric Detection

Statistical process control (SPC) charts are used to distinguish natural, random variations in a process parameter from fluctuations associated with an assignable cause, such as equipment malfunction or operator error. SPC charts are widely used in industry for quality and process control. In fact, feedback from recent graduates of the undergraduate chemical engineering program indicates that familiarity with SPC charts is one of the most valuable skills for newly hired process engineers. In the following experiment, students are introduced to the concept of SPC through a simple inline mixing experiment. Students learn to create SPC control charts and, more importantly, to understand their function.

An inline optical electron polarimeter

The design and operation of a simple inline optical electron polarimeter is presented. It is based on exchange excitation of ground state neon atoms. The electron polarization is determined from the degree of circular polarization of the subsequent 2p53p 3D3→2p53s 3P2 (6402 Å) fluorescence. This device can characterize both longitudinally and transversely polarized electron beams in a nondestructive fashion, and is inexpensive and easily constructed.

Inline function expansion for compiling C programs

Inline function expansion replaces a function call with the function body. With automatic inline function expansion, programs can be constructed with many small functions to handle complexity and then rely on the compilation to eliminate most of the function calls. Therefore, inline expansion serves a tool for satisfying two conflicting goals: minizing the complexity of the program development and minimizing the function call overhead of program execution. A simple inline expansion procedure is presented which uses profile information to address three critical issues: code expansion, stack expansion, and unavailable function bodies. Experiments show that a large percentage of function calls/returns (about 59%) can be eliminated with a modest code expansion cost (about 17%) for twelve UNIX * programs.

New Coaxial-to-Stripline Transformers Using Rectangular Lines (Correspondence)

The most common form of coaxial-to-stripline transition consists of a simple inline butt joint, as described by Barrett. A typical transition between a 50-ohm high-Q triplate and a standard N-type connector is shown in Fig. 1. This gives a VSWR<1.15 at frequencies up to 7000 Mc deteriorating to 1.25 at higher frequencies up to 11,000 Mc. While these results are acceptable for many types of stripline components and assemblies, it was felt that the design of a better transition would be necessary in order both to test and to maintain the performance of high grade components (e.g., hybrids, directional couplers, and filters) and to avoid the manufacture of a special stripline standing-wave detector.