Displacement Device Research Articles

Development of a Control Module for a Digital Electromagnetic Actuators Array

In this paper, a digital actuators array composed of 25 elementary digital actuators placed in a 5 × 5 matrix configuration is presented. The originality of the elementary digital actuator lies in its ability to reach four discrete positions in a horizontal xy-plane. An analytical model of the array is presented and has been used to design an experimental prototype. A control module is proposed to independently or simultaneously control the elementary actuators along two displacement axes. This module is based on a control strategy and on a dedicated electrical control circuit which reduces the number of channels needed to control the array. The proposed control strategy is based on position and displacement matrices to characterize the desired motion of each elementary actuator. Experimental tests of the actuators array are presented in the paper to validate the control module. Finally, an application of the array as a xy-plane displacement device is shown.

Rehabilitación oral en paciente con trastorno temporomandibular relacionado a factores oclusales

Se presenta el siguiente reporte de caso clínico: paciente de sexo femenino de 51 años de edad, edéntula parcial con maloclusión clase I que acude a la clínica de post grado al área de Rehabilitación Oral debido a los constantes ruidos y dolor periauricular con disminución del función masticatoria. El objetivo del presente reporte de caso clínico fué el diagnóstico y tratamiento del Trastorno Temporomandbular que se realizó tanto clínica como imagenologicamente a través de Resonancia Magnética de la articulación temporomandibular llegando al diagnóstico de desplazamiento discal unilateral derecha con reducción, por lo que se inicia el tratamiento en una primera fase con pacificación a través de un dispositivo oclusal de desplazamiento mandibular (DODAM) seguido de una férula estabilizadora oclusal para luego continuar con la rehabilitación protésica fija. La conclusión del presente reporte de caso clínico es dar importancia a la estabilidad articular a través del uso de férulas antes de iniciar el tratamiento de rehabilitación protésica en casos de Trastorno Temporomandibular que presentan desplazamiento discal con reducción, el conocimiento de los factores oclusales permitirá al clínico guiarse en el diagnóstico y tratamiento del trastorno temporomandibular considerando las condiciones de cada individuo.

Effects of the particle deformability on the critical separation diameter in the deterministic lateral displacement device

AbstractDeterministic lateral displacement (DLD) technology is a newly developed method which can separate microscale and nanoscale particles continuously and efficiently. In this paper, a direct numerical simulation method (i.e. a fictitious domain method) is used to simulate the motion of an elastic particle (modelled as homogeneously elastic body) in the DLD device. The effects of the particle deformability on the critical separation diameter are investigated. Our results indicate that there exists a critical deformability, below which the critical diameter decreases with increasing deformability, whereas beyond which the critical diameter increases with increasing deformability. The reasons are discussed via the consideration of the effects of the particle deformation and the lubrication force on the lateral position of the particle centre point. In addition, our results show that the increase in the gap distance between adjacent posts in both directions or in the longitudinal direction alone leads to the increase in the critical particle size with respect to the gap size, which can be explained by the lateral position of the separation streamline of the undisturbed flow.

Eureka! A reliable, home-made water volumetry device

Background Water displacement is considered to be the gold standard for measuring foot volume; however, it is time-consuming and infrequently used in clinical practice. The objectives of this study were to determine whether a home-made water displacement device is a reliable and time-efficient method for determining foot volume. Methods Thirty participants with no foot pathologies were enrolled and had their foot volume measured in two home-made water volumetry devices (Preski and PreskiLite). The participants' foot volumes were measured on two occasions on each of two different days. Results All measurements were achieved in less than 90 seconds. Within-day reliability was high (intraclass correlation [ICC]=0.997–0.999) with the minimal detectable change (MDC) at the 90% confidence level (MDC90) of less than 25 ml for both devices. Mean differences in volume displaced between days were small (range 0.6– -5.4 mls). For between-day measures on the same leg, the mean coefficient of variation ranged from 0.65–1 with associated ICCs of 0.989–0.997. The MDC90 for between-day measures was 46 ml for the PreskiLite and 23 ml for the Preski. The difference in volume displaced between right and left legs was less than the MDC90 for both devices. Conclusions A novel, home-made water volumetry device provides reliable measures of foot volume both within and between days. Measurements taken on the contralateral leg provide an adequate control. These portable devices provide rapid measurements and only one measurement is needed per day.

The use of a displacement device negatively affects the performance of dogs (Canis familiaris) in visible object displacement tasks.

Visible and invisible displacement tasks have been used widely for comparative studies of animals' understanding of object permanence, with evidence accumulating that some species can solve invisible displacement tasks and, thus, reach Piagetian stage 6 of object permanence. In contrast, dogs appear to rely on associative cues, such as the location of the displacement device, during invisible displacement tasks. It remains unclear, however, whether dogs, and other species that failed in invisible displacement tasks, do so because of their inability to form a mental representation of the target object, or simply because of the involvement of a more salient but potentially misleading associative cue, the displacement device. Here we show that the use of a displacement device impairs the performance of dogs also in visible displacement tasks: their search accuracy was significantly lower when a visible displacement was performed with a displacement device, and only two of initially 42 dogs passed the sham-baiting control conditions. The negative influence of the displacement device in visible displacement tasks may be explained by strong associative cues overriding explicit information about the target object's location, reminiscent of an overshadowing effect, and/or object individuation errors as the target object is placed within the displacement device and moves along a spatiotemporally identical trajectory. Our data suggest that a comprehensive appraisal of a species' performance in object permanence tasks should include visible displacement tasks with the same displacement device used in invisible displacements, which typically has not been done in the past.

22am2-G5 寸法選別マイクロ流体デバイスを用いた血液分級における流速の影響

Effect of fluid velocity on blood cell sorting by a deterministic lateral displacement (DLD) device was studied. In the DLD devices, large velocity gradient exists, and cells sometimes contact to micro-post array. Therefore, it is assumed that cell deformation varies with fluid velocity. We have demonstrated that sorting behavior varies with fluid velocity and cell flexibility by flowing diluted culture solution with single type of cell. Soft cells tend to behave as if smaller particle with high fluid velocity. For practical use of the device, to realize cell segregation of real blood, which is denser and various cell contained solution, is necessary. Practical blood specimen is concentrated and collision between blood cells is inevitable. In this study, real blood was tested and almost identical tendency of cell sorting behavior was confirmed.

黏度对不同渗透率稠油油藏流体渗流特征的影响

稠油中胶质、沥青质形成的结构造成的黏度异常反映了稠油油藏的特性，对稠油的渗流特征有非常重要的影响。通过配制不同含稠油比例的油样，利用流变仪和岩心驱替装置，对不同黏度油样的流变性及其在多孔介质中的渗流特征进行了实验研究，分析了黏度对稠油渗流特征的影响。结果表明：随着油样中所含稠油比例增大，多孔介质中油样的非牛顿渗流特性增强，且渗透率越小，油样的非牛顿特性表现越明显；随着油样中稠油比例增大，水相相对渗透率迅速增大，而油相相对渗透率急剧降低，导致开采效果变差，且对流体在较低渗透率岩样中的相对渗透率影响大于高渗透率的岩样；随着被驱替油样中稠油比例增加，产出液中含水率上升的速度加快，且渗透率越低，含水率随采出程度增加的速度越快。 The viscosity abnormality caused by the asphaltenes and resins in heavy oil reflects the characteristics of heavy oil reservoirs and has very important influence on seepage rule of heavy oil. The oil samples containing different heavy oil ratio were prepared. The rheological properties of different viscosity oil sample and its flow characteristics in porous media were experimentally studied by the rheometer and the core displacement device. The effects of viscosity to percolation characteristic of heavy oil were analyzed in detail. The results show the non-Newtonian seepage characteristic of oil samples in porous media enhances with increasing the proportion of heavy oil in the oil samples. The smaller the permeability of the porous media, the non-Newtonian behavior of oil samples is more obvious. As the heavy oil ratio increases, the relative permeability of water increases rapidly and the oil relative permeability decreases sharply which become worse at the oil recovery effect. The influence on relative permeability of fluids in the lower permeability cores is more than high permeability ones. The water cut increases rapidly in the produced fluids with increasing the proportion of heavy oil in the oil sample. The lower the permeability of the cores, the water cut with recovery percent increases more rapidly.

Colon-Morales’ Uterine Displacement Device

When a pregnant woman lies flat on her back, the heavy contents of her distended womb can compress one or both of her abdomen’s largest blood vessels (inferior vena cava and/or aorta). Besides alarming symptoms, maternal hypotension and even fetal demise can then occur. To help prevent this “supine hypotensive syndrome,” Dr. Miguel A. Colon-Morales invented a uterine displacement device (above), which can be attached to (or slid under the padding of) the surgical table. To shift the gravid uterus to the patient’s left and avoid compressing central vessels, a 10-inch rod is extended so that its terminal plunger ball is “placed in the space between the last floating rib and the right iliac crest.” On June, 13, 1972, Dr. Colon-Morales was granted U.S. Patent No. 3669118 for his clever “Uterine Displacement Device.” (Copyright © the American Society of Anesthesiologists, Inc.)George S. Bause, M.D., M.P.H., Honorary Curator, ASA’s Wood Library-Museum of Anesthesiology, Park Ridge, Illinois, and Clinical Associate Professor, Case Western Reserve University, Cleveland, Ohio. UJYC@aol.com.

Non-Newtonian deterministic lateral displacement separator: theory and simulations

Deterministic lateral displacement devices have been proved to be an efficient way to perform continuous particle separation in microfluidic applications (Huang et al. Science 304:987–990, 2004). On the basis of their size, particles traveling through an array of obstacles follow different paths and can be separated in outflow. One limitation of such a technique is that each device works for a specific critical size to achieve particle separation, and a new device with different geometrical properties needs to be fabricated, as the dimensions of the particles to be separated change. In this work, we demonstrate the possibility to tune the critical particle size in a deterministic lateral displacement device by using non-Newtonian fluids as suspending liquid. The analysis is carried out by extending the theory developed for a Newtonian constitutive law (Inglis et al. Lab Chip 6:655–658, 2006) to account for fluid shear-thinning. 3-D finite element simulations are performed to compute the dynamics of a spherical particle flowing through the deterministic ratchet. The results show that fluid shear-thinning, by altering the flow field between the obstacles, contributes to decrease the critical particle diameter as compared to the Newtonian case. Numerical simulations demonstrate that tunability of the critical separation size can be achieved by using the flow rate as control parameter. A design formula, relating the separation diameter to the fluid rheology and the relevant geometrical parameters of the device, is derived. Such a formula, originally developed for a power-law model, is proved to work for non-Newtonian liquids with a general viscosity trend.

Development of a biaxial tensile machine for characterization of sheet metals

A new stand-alone biaxial testing machine with out-of-plane loading system has been developed to study the anisotropic plastic behavior of metal sheets on cruciform specimens. In this apparatus a single screw driven actuator is used and the variation of the load ratio along the two main directions is achieved by adjusting the geometry of a link mechanism. This design firstly combines the advantages of biaxial displacement devices, typically mounted in a universal tensile tester, with stand-alone machines and by at the same time providing a solution to the limitations associated with each of these types. The used specimen is discussed and compared through numerical simulations to a prominent geometry proposed in the literature. Experiments are presented and the results are implemented in identifying classical and advanced yield criteria and though represented as yield surfaces.

Control of a Transitioning Boundary Layer using Surface-Mounted Electro Active Polymers

Micro air vehicles (MAV) are a major focus of aerodynamics today with many military as well as civilian applications. MAV flight is dominated by the unsteady characteristics of low Reynolds number flows. Three-dimensional separations may occur at random on different parts of the wing, causing highly unsteady forces and moments, as well as full wing stall. In the present work an Electro-Active Polymer (EAP) actuator was examined as a feasible flow control actuator with application to low Reynolds number flows. The performance of the EAP was evaluated using a laser displacement device, where the displacements generated under selected driving frequencies and input voltages were recorded. It was shown that the deflections could reach up to 0.35 mm at frequencies below 40 Hz. The surface deflection was found to be parabolic across the span and width of the actuator. Hot-wire anemometry measurements were conducted on a flat plate equipped with a trailing edge flap in a low Reynolds number wind tunnel to study t...

Gravity Driven Deterministic Lateral Displacement for Particle Separation in Microfluidic Devices

We investigate the two-dimensional continuous size-based separation of suspended particles in gravity-driven deterministic lateral displacement (g-DLD) devices. The suspended particles are driven through a periodic array of cylindrical obstacles under the action of gravity. We perform experiments covering the entire range of forcing orientations with respect to the array of obstacles and identify specific forcing angles that would lead to vector separation, in which different particles migrate, on an average, in different directions. A simple model, based on the lateral displacement induced on the trajectory of a particle by irreversible particle-obstacle interactions, accurately predicts the dependence of the migration angle on the forcing direction. The results provide design guidance for the development of g-DLD devices. We observe directional locking, which strongly depends on the size of the particle and suggests that relatively small forcing angles are well suited for size-fractionation purposes. We demonstrate excellent separation resolution for a binary mixture of particles at relatively small forcing angles, that is, forcing angles that are close to but smaller than the first transition angle of the larger particles in the mixture.

Short-term deformation behavior model of endangered earthen heritage slope after conservation in Jiaohe Ruins

Cliff deformation behavior after conservation is of great significance for evaluating the conservation effect and discovering the dynamical law of soil. Modeling on deformation behavior is beneficial to the quantitative evaluation of interactions between soil mass and structures as well as the forecast. Based on cliff conservation engineering of Jiaohe Ruins (the largest raw soil heritage site in the world), data of horizontal deformation of the upper cliff were obtained by using Nanrui-made NDW-50 displacement device (precision: 0.01 mm, frequency: 15 min−1). Regression analysis indicates that deformation behavior models include exponential growth, linear growth and parabolic growth types, while daily deformation presents more intense periodicity (24 h). The deformation is less than 1.5 mm during monitoring period, which has no impact on the stability of cliff. Deformation behavior provides the mutual duress and interaction between soil and engineering intervention. In addition, deformation mode attaches tensely to the damage pattern of the cliff. The conclusions are of importance to the stability evaluation of the carrier along Silk Road.

Design and analysis of DNA strand displacement devices using probabilistic model checking

Designing correct, robust DNA devices is difficult because of the many possibilities for unwanted interference between molecules in the system. DNA strand displacement has been proposed as a design paradigm for DNA devices, and the DNA strand displacement (DSD) programming language has been developed as a means of formally programming and analysing these devices to check for unwanted interference. We demonstrate, for the first time, the use of probabilistic verification techniques to analyse the correctness, reliability and performance of DNA devices during the design phase. We use the probabilistic model checker prism, in combination with the DSD language, to design and debug DNA strand displacement components and to investigate their kinetics. We show how our techniques can be used to identify design flaws and to evaluate the merits of contrasting design decisions, even on devices comprising relatively few inputs. We then demonstrate the use of these components to construct a DNA strand displacement device for approximate majority voting. Finally, we discuss some of the challenges and possible directions for applying these methods to more complex designs.

Changes in condylar cartilage after anterior mandibular displacement in juvenile pigs

Adaptive remodelling of the mandibular condyle in response to mandibular advancement is the mechanism exploited by orthodontic forward displacement devices. ObjectiveThis work investigated the expression of collagens, matrix metalloproteinases and vascular endothelial growth factor during this process. DesignTwenty juvenile pigs were randomly divided into two experimental groups, where the treatment group was fitted with mandibular advancement splints, and the control group was not. Changes in the mRNA content of condylar cartilage tissue was then were measured by real-time PCR using specific primers after 4weeks of treatment. ResultsThe temporal pattern of the expression of Col1 and MMP13 during condylar adaptation coincided with that during natural condylar growth. The amount of the expression of Col10 during condylar adaptation was significantly lower (p<0.05), whereas the expression of Col2, MMP8 and VEGF was significantly higher compared to natural growth (p<0.05). ConclusionsIt is suggested that condylar adaptation in growing pigs triggered by mandibular forward positioning results not only from passive adaptation of cartilage, but also involves growth affected processes. Our results showed that mechanical strain produced by mandibular advancement induced remodelling and revascularization in the posteriocranial mandibular condyle. These results are mostly consistent with former published histological and histomorphometrical analyses.

Abstractions for DNA circuit design

DNA strand displacement techniques have been used to implement a broad range of information processing devices, from logic gates, to chemical reaction networks, to architectures for universal computation. Strand displacement techniques enable computational devices to be implemented in DNA without the need for additional components, allowing computation to be programmed solely in terms of nucleotide sequences. A major challenge in the design of strand displacement devices has been to enable rapid analysis of high-level designs while also supporting detailed simulations that include known forms of interference. Another challenge has been to design devices capable of sustaining precise reaction kinetics over long periods, without relying on complex experimental equipment to continually replenish depleted species over time. In this paper, we present a programming language for designing DNA strand displacement devices, which supports progressively increasing levels of molecular detail. The language allows device designs to be programmed using a common syntax and then analysed at varying levels of detail, with or without interference, without needing to modify the program. This allows a trade-off to be made between the level of molecular detail and the computational cost of analysis. We use the language to design a buffered architecture for DNA devices, capable of maintaining precise reaction kinetics for a potentially unbounded period. We test the effectiveness of buffered gates to support long-running computation by designing a DNA strand displacement system capable of sustained oscillations.

The development and investigation of devices for the parallel displacement of a beam of radiation for the channel automatic adjustment systems of laser location stations

The features of the development of the optical arrangements of radiation beam parallel displacement devices, which preserve the information on the direction of propagation of the beam in space, are considered. An original optical arrangement, constructed using pentaprisms, is proposed and investigated. A method of measuring the angular coordinates of a beam using such a system is developed and its accuracy characteristics are analyzed.

The Roadway Surrounding Rock Delaminating Displacement Monitoring Technology Based on Moiré Technique

With the coalface excavates, surrounding rock of roadway will occur deformation in different degrees. When the rock deformation exceeds a certain limit, roof fall and spalling would occur. To prevent such accidents, it is very important to monitor deformation of the surrounding rock in real-time. In this paper, Moiré measurement theory is elaborated. The displacement device (GWG200(C)), based on moiré technique, are applied in ventilation tunnel of 1015 working face in Xing Ge Zhang Mine to monitor deformation. The real time datum of deformation are obtained. The system provides technique safeguard for safety production.

Neither Here Nor Elsewhere: Displacement Devices in Representing the Supernatural

How might the supernatural be represented in those religious paintings that imply a continuity between the virtual space of painting and the real space of the beholder? Such an implied continuity, dependent upon an engagement where the beholder imaginatively realigns her frame of reference to that of the picture, might be thought to threaten a necessary distance demanded of religious works. This paper examines how a number of painters exploited innovative displacement devices, utilizing inherent ambiguities as to where a painting is relative to its beholder through the withholding of perspectival distance and positional cues for a discrete section of the work.

Separation of deformable particles in deterministic lateral displacement devices

Using numerical simulations, we study the separation of deformable bodies, such as capsules, vesicles, and cells, in deterministic lateral displacement devices, also known as bump arrays. These arrays comprise regular rows of obstacles such as micropillars whose arrangements are shifted between adjacent rows by a fixed amount. We show that, in addition to the zigzag and laterally displaced trajectories that have been observed experimentally, there exists a third type of trajectory which we call dispersive, characterized by seemingly random bumpings off the micropillars. These dispersive trajectories are observed only for large and rigid particles whose diameters are approximately more than half the gap size between micropillars and whose stiffness exceeds approximately 500 MPa. We then map out the regions in phase space, spanned by the row shift, row separation, particle diameter, and particle deformability, in which the different types of trajectories are expected. We also show that, in this phase space, it is possible to transition from zigzag to dispersive trajectories, bypassing lateral displacement. Experimentally, this is undesirable because it limits the ability of the device to sort particles according to size. Finally, we discuss how our numerical simulations may be of use in device prototyping and optimization.