Standard Blocks Research Articles

From chip-in-a-lab to lab-on-a-chip: a portable Coulter counter using a modular platform

The field of microfluidics has been struggling to obtain widespread market penetration. In order to overcome this struggle, a standardized and modular platform is introduced and applied. By providing easy-to-fabricate modular building blocks which are compatible with mass manufacturing, we decrease the gap from lab-to-fab. These standardized blocks are used in combination with an application-specific fluidic circuit board. On this board, electrical and fluidic connections are demonstrated by implementing an alternating current Coulter counter. This multipurpose building block is reusable in many applications. In this study, it identifies and counts 6 and 11 μm beads. The system is kept in a credit card-sized footprint, as a result of in-house-developed electronics and standardized building blocks. We believe that this easy-to-fabricate, credit card-sized, modular, and standardized prototype brings us closer to clinical and veterinary applications, because it provides an essential stepping stone to fully integrated point -of -care devices.

Investigation of transients during start-up of hybrid synchronous electric motor of submersible oil pump with permanent magnets

The results of simulation of transients during the start-up of a hybrid synchronous electric motor with permanent magnets under various loads are presented in this paper. The proposed motor was tested for no-load, full load, and overload using the MATLAB software and Simulink blocks. The model in the Matlab is elaborated using standard blocks library of SimPowerSystems. Also, the possibility of starting the proposed motor at the direct connection to the grid is considered. The velocity-time graphs and electromagnetic torque-time graphs are presented in the paper.

Optofluidic Modular Blocks for On-Demand and Open-Source Prototyping of Microfluidic Systems.

Rapid prototyping of microfluidic devices has advanced greatly, along with the development of 3D printing and micromachining technologies. However, peripheral systems for microfluidics still rely on conventional equipment, such as bench-top microscopy and syringe pumps, which limit system modification and further improvements. Herein, optofluidic modular blocks are presented as discrete elements to modularize peripheral optical and fluidic systems and are used for on-demand and open-source prototyping of whole microfluidic systems. Each modular block is fabricated by embedding optical or fluidic devices into the corresponding 3D-printed housing. The self-interlocking structure of the modular blocks enables easy assembly and reconfiguration of the blocks in an intuitive manner, while also providing precise optical and fluidic alignment between the blocks. With the library of standardized modular blocks developed here, how the blocks can be easily assembled to build whole microfluidic systems for blood compatibility testing, droplet microfluidics, and cell migration assays is demonstrated. Based on the simplicity of assembling the optofluidic blocks, the prototyping platform can be easily used for open-source sharing of digital design files, assembly and operation instructions, and block specifications, thereby making it easy for nonexperts to implement microfluidic ideas as physical systems.

Core executive functions are selectively related to different facets of motor competence in preadolescent children

Background: Although accumulating evidence suggests that motor and cognitive development is interrelated, only a few studies have investigated links between executive function and motor control. Therefore, the present cross-sectional study examined the relationship between motor competences and core components of executive functioning, including inhibitory control, working memory and cognitive flexibility. Methods: In 89 preadolescent children, motor competences were assessed using the MOBAK-5 test battery. Additionally, all participants completed computer-based versions of the Flanker task, which included standard and switch blocks, and the 2-Back task. Results: Partial correlations (correcting for age, gender and body mass index) revealed that locomotor skills were associated with the adjusted hit-rate on the 2-Back task (r = 0.34) whereas object control was linked with conflict score on the Flanker task (r = −0.39). In contrast, there was no correlation between switch costs and motor competences. Conclusion: In preadolescent children, high competences in locomotor skills and object control skills are associated with high performance on specific executive function tasks. This finding supports the current view that motor competences and cognitive control share some common underlying processes.

Not all lightweight lead aprons and thyroid shields are alike

ObjectiveWith the explosion of minimally invasive surgery, the use of fluoroscopy has significantly increased. Concurrently, there has been a demand for lighter weight aprons. The industry answered this call with the development of lightweight aprons. Our goal was to see whether lighter weight garments provide reduced protection. MethodsDry laboratory testing was performed in a standard X-ray room, using a standard fluoroscopy table and standard acrylic blocks. A commercial-grade pressurized ion chamber survey meter (Ludlum Model 9DP; Ludlum Measurements, Inc, Sweetwater, Tex) was used to detect gamma rays and X-rays above 25 keV. Nonlead aprons from several manufacturers were tested for scatter radiation penetration above the table at a fixed distance (3 feet) and compared with two standard 0.5-mm lead aprons of different manufacturers. ResultsScatter measurements were made at 60 kVp and 70 kVp for pure lead (0.5 mm), mixed, and nonlead protective garments. Scatter penetration for the nonlead blends and barium aprons was 292% and 258%, respectively, at 60 kVp compared with the pure lead apron. At the higher beam quality of 70 kVp, the scatter penetration was 214% and 233% for the blend and barium aprons, respectively, compared with the pure lead apron. Our measurements demonstrate a noticeable difference in scatter reduction between pure lead and nonlead garments. Pure barium aprons and nonlead aprons from certain companies demonstrated scatter penetration that is inconsistent with the 0.5 mm of lead equivalence as claimed on the label. In addition, there was an incidental finding of a handful of lightweight aprons with significant tears along the seams, leaving large gaps in protection. Our study also demonstrates that several companies rate their lightweight garments as 0.5 mm lead equivalent, when actually only a small area on the chest and abdomen where the garment overlapped was 0.5 mm, leaving the rest of the garment with half the protection at 0.25 mm. ConclusionsOur reliance on protective lead garments to shield us from the biologic effects of radiation exposure and the inferiority of some lightweight garments necessitate a streamlining of the testing methods and transparency in data reporting by manufacturers.

Apical preparation size after repetitive pecking to the working length using different endodontic file systems

AimThe purpose of this study was to determine and evaluate the apical preparation size resulting from different pecking times to the working length (WL) with five different file systems. Materials and methodsFifty standard simulated endodontic J-shaped blocks were instrumented using ProTaper NEXT (PTN), WaveOne (WO), WaveOne Gold (WOG), OneShape (OS) and the Self-Adjusting File (SAF) (n=10) with different pecking times (1, 2 and 4) to the WL. For the SAF group, instrumentation was done till WL according to the time, i.e. 1, 3 and 4min. On completion of each stage, silicone impression material was used to take canal impressions for comparison and evaluation of the apical size preparation, using a stereomicroscope. Two-way analysis of variance was applied to determine differences between groups and pecking times. ResultsAfter four pecking times, a significant increase was observed in the apical diameter of four test groups compared to SAF (P<0.05), which was not associated with increased apical preparation at all times. ConclusionA greater apical enlargement occurs with increasing pecking times; however, SAF instrumentation exhibits the minimum changes in the apical preparation after 1, 3 and 4min. WO, WOG and OS are able to prepare the apical size similar to their tip at a single peck to the WL.

An efficient redundant binary adder with revised computational rules

Redundant binary representation (RBR) offers a carry-free addition of two redundant binary (RB) numbers. The computational rules of the conventional RB adder (CRBA) generate intermediate sum and carry vectors in RBR, leads to area overhead and pre-hardware elements for reverse conversion (RC). We have considered that the intermixing of inverted encoding of negabits (IEN) representation and conventional binary bits or posibits can be realized using standard hardware blocks. This paper provides a new computational rule for RB adder generating the intermediate sum and intermediate carry in posibit and IEN representations replacing the redundant digits. Thus, the proposed RB adder provides a single stage RB adder omitting the requirement of intermediate RB digits. For circuit synthesis of the proposed designs, we have considered Encounter® RTL Compiler and Xilinx Synthesis Technology in ASIC and FPGA platforms respectively. The comparative study of proposed NRBA offers improved design parameters as compared to CRBA.

Optical fiber based soft curvature sensor with polyvinyl chloride reinforced silicone rubber substrate

To meet the demands for curvature measurement in the field of biomedical intelligent equipment, soft robots and complex structures of major infrastructures, an optical fiber based soft curvature sensor is proposed. The major contribution is obtaining a soft curvature sensor with extraordinary high sensitivity and repeatability. A silicone rubber sheet is glued on the surface of polyvinyl chloride to form polyvinyl chloride (PVC) reinforced silicone rubber substrate, the fiber Bragg grating is embedded into the substrate to form the sensor. The sensor is calibrated using standard curvature calibration blocks. The characteristic of the reflected spectrum of the sensor is analyzed. The relation between the sensitivity and the fiber embedded depth is obtained. The research results prove that the real-time measurement of structure curvature can be realized by the sensor. The polyvinyl chloride reinforced silicone rubber substrate is helpful to improve the sensitivity and repeatability of the sensor. The maximum sensitivity is up to 329.2pm/m−1. The sensor has good consistency in repeated measurements, it has application presents in measuring the curvature of flexible mechanisms and complex structures.

A Temperature-Dependent SPICE Model of SiC Power MOSFETs for Within and Out-of-SOA Simulations

This paper presents a temperature-dependent SPICE model for SiC power MOSFETs. The model describes the static and dynamic behavior and accounts for leakage current and impact ionization. The technology-dependent mosfet parameters are extracted from characterization measurements and datasheets. SPICE standard components and analog behavior modeling blocks are adopted for the model implementation. The model ensures a good agreement with experimental data over a wide temperature range, even under out-of-safe-operating-area (SOA) conditions close to the failure occurrence.

Accelerating the computation of FLAPW methods on heterogeneous architectures

Legacy codes in computational science and engineering have been very successful in providing essential functionality to researchers. However, they are not capable of exploiting the massive parallelism provided by emerging heterogeneous architectures. The lack of portable performance and scalability puts them at high risk: either they evolve or they are doomed to disappear. One example of legacy code which would heavily benefit from a modern design is FLEUR, a software for electronic structure calculations. In previous work, the computational bottleneck of FLEUR was partially re-engineered to have a modular design that relies on standard building blocks, namely BLAS and LAPACK. In this paper, we demonstrate how the initial redesign enables the portability to heterogeneous architectures. More specifically, we study different approaches to port the code to architectures consisting of multi-core CPUs equipped with one or more coprocessors such as Nvidia GPUs and Intel Xeon Phis. Our final code attains over 70\% of the architectures' peak performance, and outperforms Nvidia's and Intel's libraries. Finally, on JURECA, the supercomputer where FLEUR is often executed, the code takes advantage of the full power of the computing nodes, attaining $5\times$ speedup over the sole use of the CPUs.

Research on Guarantee Technology of Measurement Accuracy of Pavement Damage Detection Equipment

Whether the tests result of road damage rate is accurate or not, it is affected by many factors. The article describes the measurement standards developed for pavement damage detection equipment, including pavement damage measurement standard devices and pavement damage standard test blocks. The pavement damage measurement standard device detects pavement cracks through image recognition technology and measures its geometric parameters. The pavement damage standard test block simulates the pavement texture using engineering plastics, and then uses a laser engraving process to process typical pavement cracks to realistically reproduce the actual form of pavement cracks. The article gives a metrological traceability diagram of the amount of pavement damage detection equipment, and carries out repeatability tests and stability tests to verify the measurement standards.

Peripheral infrastructure vectors and an extended set of plant parts for the Modular Cloning system.

Standardized DNA assembly strategies facilitate the generation of multigene constructs from collections of building blocks in plant synthetic biology. A common syntax for hierarchical DNA assembly following the Golden Gate principle employing Type IIs restriction endonucleases was recently developed, and underlies the Modular Cloning and GoldenBraid systems. In these systems, transcriptional units and/or multigene constructs are assembled from libraries of standardized building blocks, also referred to as phytobricks, in several hierarchical levels and by iterative Golden Gate reactions. Here, a toolkit containing further modules for the novel DNA assembly standards was developed. Intended for use with Modular Cloning, most modules are also compatible with GoldenBraid. Firstly, a collection of approximately 80 additional phytobricks is provided, comprising e.g. modules for inducible expression systems, promoters or epitope tags. Furthermore, DNA modules were developed for connecting Modular Cloning and Gateway cloning, either for toggling between systems or for standardized Gateway destination vector assembly. Finally, first instances of a “peripheral infrastructure” around Modular Cloning are presented: While available toolkits are designed for the assembly of plant transformation constructs, vectors were created to also use coding sequence-containing phytobricks directly in yeast two hybrid interaction or bacterial infection assays. The presented material will further enhance versatility of hierarchical DNA assembly strategies.

Directional power distribution and mode selection in micro ring lasers by controlling the phase and strength of filtered optical feedback.

We discuss the design and characterization of a micro ring laser with on-chip filtered optical feedback. The laser and feedback section have been fabricated on a generic photonic integration platform using only standard building blocks. The filtering process in the feedback scheme is based on the reflection from a distributed Bragg reflector. We include several control pads in the feedback section which allows us to control separately the wavelength, the strength and the phase of the filtered feedback. By controlling the phase of the feedback, we can fine-tune the longitudinal mode selection and wavelength of the laser output, while changing the strength of the feedback allows us to control the power distribution between the two directions of the micro ring laser. Numerical simulations reproduce our experimental observations.

FBDTester 2.0: Automated test sequence generation for FBD programs with internal memory states

As Function Block Diagram (FBD) programs are used to implement safety-critical systems such as nuclear reactor protection systems, it is crucial to generate effective test cases. FBD programs are running on programmable logic controllers (PLCs) that execute the programs repeatedly within a particular scan time. Among the elements of FBD programs, function blocks and feedback variables save the inputs or outputs of the previous scan cycle into internal memories. The data stored in the internal memory are used to operate the function blocks of the next scan cycle. Researchers have recently developed an automated test generation technique aiming to satisfy several structural test coverage criteria for FBD programs. Among them, Jee et al.'s approach has an advantage of generating tests from FBD programs without requiring any intermediate models. However, test sequence generation for FBD programs with internal memory states was not fully automated in Jee et al.'s approach. This paper extends Jee et al.'s work by generating test sequences from FBD programs with internal memory states in a fully automated manner. The key technique involves explicitly unwinding FBD programs and solving the test requirements using an SMT solver. We conduct experiments on increasing the coverage of test requirements by unwinding cycles and evaluating the effectiveness of the test set using mutation analysis with several subject programs, including a real-world reactor protection system. The experimental results show that the proposed approach is able to generate effective test sequences for FBD programs. To demonstrate the efficiency of the proposed approach, we compared the test sequence generation time required for our approach with those for other approaches. The comparison results show that even excluding the generation time of test models of other approaches, the proposed approach increased the time-efficiency by more than 11 times. • Developing algorithms to generate test sets for Function Block Diagram programs. • Defining Function Block Conditions for all the standard function blocks. • Implementing an automated test sequence generation tool using Yices SMT solver. • Demonstrating improved fault-detection effectiveness and time efficiency.

Comparative analysis of canal transportation using reciproc blue and wavo one gold in simulated root canals using different kinematics

ObjectiveThe purpose of the current study was to assess and compare the shaping ability of WaveOne Gold and Reciproc Blue in reciprocation and counter clock wise rotation using standardized resin blocks and to assess time required to reach full working length. MethodologyA total of 52 curved canals in clear resin blocks with 30° angle of curvature and 16 mm canal length were used in this study. The blocks were divided into 4 groups according to the instrument and motion utilized into: Reciproc Blue/Reciprocation (RB/R) group, Reciproc Blue/counter clock wise rotation (RB/CCW) group, WaveOne gold/Reciprocation (WG/R) and WaveOne gold/Counter clock wise rotation (WO/RCR). Standardized digital images were taken prior and post instrumentation. Then, Adobe Photoshop was used to superimpose post and pre-instrumentation images to evaluate the degree of canal transportation. Digital chronometer was used to record the time required for canal preparation. One-way ANOVA followed by Tukey post hoc test was used to compare between more than two groups in non-related samples. ResultsNo statistically significant difference was noted among all groups at the apical and middle thirds levels. As for the preparation time, both groups; RB/R and RB/CCW recorded significantly longer time than groups; WG/R and WG/CCW (P < 0.001). ConclusionsThe use of single-file in counter clock wise rotation showed favourable results in terms of avoiding canal transportation and preparation time.

Effect of neuromonitor-guided titrated care on brain tissue hypoxia after opioid overdose cardiac arrest

IntroductionBrain tissue hypoxia may contribute to preventable secondary brain injury after cardiac arrest. We developed a porcine model of opioid overdose cardiac arrest and post-arrest care including invasive, multimodal neurological monitoring of regional brain physiology. We hypothesized brain tissue hypoxia is common with usual post-arrest care and can be prevented by modifying mean arterial pressure (MAP) and arterial oxygen concentration (PaO2). MethodsWe induced opioid overdose and cardiac arrest in sixteen swine, attempted resuscitation after 9 min of apnea, and randomized resuscitated animals to three alternating 6-h blocks of standard or titrated care. We invasively monitored physiological parameters including brain tissue oxygen (PbtO2). During standard care blocks, we maintained MAP > 65 mmHg and oxygen saturation 94–98%. During titrated care, we targeted PbtO2 > 20 mmHg. ResultsOverall, 10 animals (63%) achieved ROSC after a median of 12.4 min (range 10.8–21.5 min). PbtO2 was higher during titrated care than standard care blocks (unadjusted β = 0.60, 95% confidence interval (CI) 0.42–0.78, P < 0.001). In an adjusted model controlling for MAP, vasopressors, sedation, and block sequence, PbtO2 remained higher during titrated care (adjusted β = 0.75, 95%CI 0.43–1.06, P < 0.001). At three predetermined thresholds, brain tissue hypoxia was significantly less common during titrated care blocks (44 vs 2% of the block duration spent below 20 mmHg, P < 0.001; 21 vs 0% below 15 mmHg, P < 0.001; and, 7 vs 0% below 10 mmHg, P = .01). ConclusionsIn this model of opioid overdose cardiac arrest, brain tissue hypoxia is common and treatable. Further work will elucidate best strategies and impact of titrated care on functional outcomes.

MiYA, an efficient machine-learning workflow in conjunction with the YeastFab assembly strategy for combinatorial optimization of heterologous metabolic pathways in Saccharomyces cerevisiae

Facing boosting ability to construct combinatorial metabolic pathways, how to search the metabolic sweet spot has become the rate-limiting step. We here reported an efficient Machine-learning workflow in conjunction with YeastFab Assembly strategy (MiYA) for combinatorial optimizing the large biosynthetic genotypic space of heterologous metabolic pathways in Saccharomyces cerevisiae. Using β-carotene biosynthetic pathway as example, we first demonstrated that MiYA has the power to search only a small fraction (2–5%) of combinatorial space to precisely tune the expression level of each gene with a machine-learning algorithm of an artificial neural network (ANN) ensemble to avoid over-fitting problem when dealing with a small number of training samples. We then applied MiYA to improve the biosynthesis of violacein. Feed with initial data from a colorimetric plate-based, pre-screened pool of 24 strains producing violacein, MiYA successfully predicted, and verified experimentally, the existence of a strain that showed a 2.42-fold titer improvement in violacein production among 3125 possible designs. Furthermore, MiYA was able to largely avoid the branch pathway of violacein biosynthesis that makes deoxyviolacein, and produces very pure violacein. Together, MiYA combines the advantages of standardized building blocks and machine learning to accelerate the Design-Build-Test-Learn (DBTL) cycle for combinatorial optimization of metabolic pathways, which could significantly accelerate the development of microbial cell factories.

Temperature Sensitivity and Compensation on a Reconfigurable Platform

This brief investigates temperature compensation techniques for circuits and systems on a reconfigurable platform. The work demonstrates use of large-scale reconfigurable system-on-chip for reducing the variability of circuits and systems compiled on a floating gate (FG)-based field-programmable analog array (FPAA). The work presents current and voltage reference which could help in reducing the variability caused due to changes in temperature. These references are standard blocks in the Scilab/Xcos environment, which could be easily compiled on the FPAA. An FG-based current reference is then used for biasing a second-order $G_{m}-C$ bandpass filter to demonstrate the compilation and usage of these voltage/current reference in a reconfigurable fabric. The large-scale FG FPAA presented here is fabricated in 350-nm CMOS process.

A Comparative Analysis of Transient Processes in an Asynchronous Motor

The results of an investigation of an asynchronous motor in the modes of direct starting and load changing obtained with mathematical modeling using a block of nonlinear systems of Lookup Table type and functional block Fcn of the MATLAB/Simulink software package. Introducing the above-mentioned elements into the model makes it possible to simply take into account changes in the parameters of an electrical machine caused by saturation of the magnetic circuit and the effect of current displacement in the rotor bars in transient modes. The saturation of the magnetic system when passing the main magnetic flux and leakage fluxes is taken into account using functional dependences, which are specified in the blocks by tabular methods, which provides model simplicity and clarity of the modeling process. Unlike a model created based on a standard block of an electric motor of Asynchronous Machine type, the proposed variant makes it possible to observe the changes of any variables of asynchronous machine during the transition process and creates good preconditions for various investigations of electric drives. Using the developed model. the comparative analysis was done of dynamic characteristics, which revealed that the transient processes in the asynchronous motor under direct starting, taking into account the saturation of the magnetic circuit and the effect of current displacement in the rotor flow that is 1.5 times faster than in the ideal machine. In addition, the first maximum of torque is 1.6 times greater than in a simplified motor model. Under a load surge, the differences in the curves of changes of torques and angular velocities are insignificant. If to neglect the effect of current displacement in the rotor bars, the transient processes do not coincide only when starting. The most essential differences are observed between the transient characteristics of the developed model and the model composed of the standard MATLAB Simulink blocks. The obtained results make it possible to draw a conclusion as to the effectiveness of applying the developed motor model when investigation of dynamical modes, selecting a starting and protective equipment of asynchronous electric drives.

Improving Gross Count Gamma-Ray Logging in Uranium Mining With the NGRS Probe

AREVA Mines and the Nuclear Measurement Laboratory of CEA Cadarache are collaborating to improve the sensitivity and precision of uranium concentration measurement by means of gamma-ray logging. The determination of uranium concentration in boreholes is performed with the Natural Gamma Ray Sonde (NGRS) based on a NaI(Tl) scintillation detector. The total gamma count rate is converted into uranium concentration using a calibration coefficient measured in concrete blocks with known uranium concentration in the AREVA Mines calibration facility located in Bessines, France. Until now, to take into account gamma attenuation in a variety of boreholes diameters, tubing materials, diameters and thicknesses, filling fluid densities, and compositions, a semiempirical formula was used to correct the calibration coefficient measured in Bessines facility. In this paper, we propose to use Monte Carlo simulations to improve gamma attenuation corrections. To this purpose, the NGRS probe and the calibration measurements in the standard concrete blocks have been modeled with Monte Carlo N-Particles (MCNP) computer code. The calibration coefficient determined by simulation 5.3 $\text{s}^{-1}\cdot \text {ppm}_{U}^{-1}$ with 10% accuracy is in good agreement with the one measured in Bessines (and for which no uncertainty was provided), 5.2 $\text{s}^{-1}\cdot \text {ppm}_{U}^{-1}$ . The calculations indicate that the concrete blocks used for measuring the calibration coefficients measured in Bessines are underestimated by about 10%. Based on the validated MCNP model, several parametric studies have been performed. For instance, the rock density and chemical composition proved to have a limited impact on the calibration coefficient. However, gamma self-absorption in uranium leads to a nonlinear relationship between count rate and uranium concentration beyond approximately 1% of uranium weight fraction, the underestimation of the uranium content reaching more than a factor 2.5 for a 50% uranium weight fraction. Parametric studies have also been performed with different tubing materials, diameters, and thicknesses, as well as different borehole filling fluids representative of real measurement conditions, in view to validate gamma attenuation corrections based on the semiempirical formula. In addition, a multilinear analysis approach has been tested to further improve accuracy on uranium concentration determination, leading to only a few percent uncertainties on a large range of configurations.