Miracle-dz/UniFAR-FTUs huggingface dataset:
Oriented and Vectorial Patterning of Cardiac Myocytes Using a Microfluidic Dielectrophoresis Chip - Towards Engineered Cardiac Tissue with Controlled Macroscopic Anisotropy

Recently, the ability to create engineered heart tissues with a preferential cell orientation has gained much interest. Here, we present a novel method to construct a cardiac myocyte tissue-like structure using a combination of dielectrophoresis and electro-orientation via a microfluidic chip. Using the interdigitated-castellated microelectrodes, the induction of a mutually attractive dielectrophoretic force between cardiac myocytes can lead the cells moving close to each other and forming a tissue-like structure with orientation along the AC electric field between the electrode gaps. Both experimental results and theoretical analysis have indicated that a large orientation torque and force can be achieved by choosing an optimal frequency and decreasing the conductivity of the medium to a low level, where the orientation torque weakly depends on the frequency. In this paper, electromechanical experiments were performed to demonstrate the structural and functional anisotropy of the electro-oriented structure.
Direct Torque Control of Four-Switch Brushless DC Motor With Non-Sinusoidal Back EMF

This paper presents a direct torque control (DTC) technique for brushless dc (BLDC) motors with non-sinusoidal back electromotive force (EMF) using a four-switch inverter in the constant torque region. This approach introduces a two-phase conduction mode as opposed to the conventional three-phase DTC drives. Unlike conventional six-step current and voltage control schemes, by properly selecting the inverter voltage space vectors from a simple look-up table at a predefined sampling time, the desired quasi-square wave current is obtained. Therefore, a much faster torque response is achieved compared to conventional current and voltage control schemes. In addition, for effective torque control, a novel switching pattern incorporating the voltage vector look-up table is designed and implemented for a four-switch inverter to produce the desired torque characteristics. Furthermore, to eliminate the low-frequency torque oscillations, pre-stored back EMF constant versus position look-up tables are designed and used in the torque estimation. As a result, it is possible to achieve two-phase conduction DTC of a BLDC motor drive with faster torque response due to the fact that the voltage space vectors are directly controlled. A theoretical concept is developed and the validity and effectiveness of the proposed DTC scheme are verified through the simulations and experimental results.
Utilization of a Measurement Based CAD Tool for Enhanced PA Design Investigations

This paper outlines the use of a measurement based waveform CAD tool for enhanced PA design. Two measurement based models have been used to simulate a complete Doherty power amplifier together with output matching. The output matching network and auxiliary bias were optimised to produce a region of high efficiency typical of Doherty power amplifiers. Through the incorporation of a large signal de-embedding network, the current and voltage waveforms were accessed at the current generator plane. This allowed for the confirmation of Doherty operation on an individual device basis. This powerful tool allows for further optimisation of power amplifiers using well established waveform design procedures, previously not possible at high power levels.
Dynamic Performance of a Modular Multilevel Back-to-Back HVDC System

The modular multilevel converter (MMC) is a newly introduced switch-mode converter topology with the potential for high-voltage direct current (HVDC) transmission applications. This paper focuses on the dynamic performance of an MMC-based, back-to-back HVDC system. A phase-disposition (PD) sinusoidal pulsewidth modulation (SPWM) strategy, including a voltage balancing method, for the operation of an MMC is presented in this paper. Based on the proposed PD-SPWM switching strategy, a mathematical model for the MMC-HVDC system, under both balanced and unbalanced grid operation modes, is developed. Dynamic performance of the MMC-based back-to-back HVDC converter system, based on time-domain simulation studies in the PSCAD/EMTDC environment, is then evaluated. The reported time-domain simulation results show that based on the adopted PD-SPWM switching strategy, the MMC-HVDC station can respond satisfactorily to the system dynamics and control commands under balanced and unbalanced conditions while maintaining voltage balance of the dc capacitors.
Using ultrasound and photoacoustics to monitor in situ forming implant structure and drug release

Most chemotherapeutics (CTs) are delivered systemically, causing nausea, hair loss, fatigue and a compromised immune system. Biocompatible in situ forming implants (ISFIs) are drug delivery vehicles which are injected as a liquid before solidifying in tissues and ultimately breaking down. By dissolving CTs in an ISFI solution, they can be injected directly to the tumour site and released in a controllable manner. ISFIs can provide localized, continuous release of CT, reducing side effects. The complex phase change of ISFIs causes a variable release rate of CT. In this work, photoacoustic (PA) imaging was used for the first time to monitor a dye (mimicking CT) diffusing into a tissue mimicking phantom while quantitative ultrasound (QUS) was used to monitor the changes in the ISFI structure. ISFIs made of poly(lactic-co-glycolic acid) and Janus Green B dye dissolved in N-methyl-2-pyrrolidone in a 39:1:60 ratio were injected in tissue mimicking polyacrylamide phantoms containing titanium oxide. ISFI structure and drug release was monitored over 72 hours. At each time point, 47 planes of the phantoms were imaged using both PA (700nm) and US using the VevoLAZR system. Regions of interest within and proximal to the ISFI were selected, and average PA and QUS parameters were determined for each plane as a function of time postimplantation. This work shows the potential of PA and QUS for monitoring kinetic drug release.
A distributed System for Radiation Monitoring at Linear Accelerators

The paper presents a system for an on-line neutron fluence monitoring at a linear accelerator. The system consists of a SRAM-based detector and a radiation-tolerant read-out system. The neutron fluence is measured in several locations of the accelerator. Monitoring of the radiation environment in an accelerator tunnel is necessary to assure a reliable long-term operation of electronic systems placed in the tunnel. The monitoring of the chamber is especially important during the design stage of a linear accelerator. The new design of 20 GeV linear accelerator X-FEL (X-ray Free Electron Laser) is currently approved for construction at DESY Research Centre in Hamburg [1], [2]. The presented paper is based on our research and experimental measurement carried out at 1.2 GeV superconducting electron linac driving the VUV-FEL. The application of a pair of TLD-700 and TLD-500 or superheated emulsion (bubble) dosimeters enables the supervision of neutrons fluence in accelerators [3]. This process requires continuous and arduous calibration of TLD, therefore this method is not convenient. Moreover, it is impossible to monitor the radiation environment in real time. The presented system fill the market nitche of real-time neutron monitoring for high-energy accelerators. Neutron fluence and gamma dose measured in this way can be used for the detailed analysis of the VUV-FEL or X-FEL environments. Monitoring of the radioactive area in a linear accelerator tunnel could be helpful to diagnose and reduce beam losses [4], [5]. We have conducted experiments with the distributed system dedicated to neutron flux measurement at the DESY Research Centre in Hamburg. The devices were exposed to a neutron field from an Americium-Beryllium (n, alpha) source 241 AmBe. The systems were installed in two accelerators: Linac II and VUV-FEL.
Transitions in the Design Process

The proposed research uses empirical methods to investigate designers’ use of research throughout the design process with an emphasis on research and idea generation. The goal is to explore the factors which impact the various phases of the design process. The early phase of the design process is often referred to as the “fuzzy front end” where many variables are still in play and the design direction is not completely agreed upon. This is also when the designer is conducting user research. The connection between the user research and the design solutions that designers move forward is critical. This connection creates a space in which the designer can ensure they are approaching this process as a user-centered process. This research explores these topics through observation of junior level industrial design students at one Midwestern university in a project-based design studio and takes place for the duration of one project. A total of four students were observed. The structure was set up that they were a team for early research, then splitting into three separate projects where two students worked together and two worked individually. The researcher’s observations for each designer are then followed up by a reflection interview in which the designer was asked to reflect on their own design process and to investigate their thought processes in choosing which research information they felt applied to their solutions and how this implementation might impact the outcome. This method is used to observe actions and behaviors during the design process allowing for observation of designers in their natural setting. Therefor the question of what happens to research throughout the design process is explored. Building on new research in cognitive and decision sciences, along with studies of
Observation of Neutron-Induced Signals Using Two-Dimensional Micro-Pixel Gas Chamber

A gas-based neutron detection system which reads out individual channels with a micro-pixel detector element was constructed, and preliminary neutron irradiation tests were conducted. The detection system consisted of a micro-pixel detector element, a gas chamber that had feedthroughs for lines of 541 channels, amplifier-shaper-discriminator boards, position encoders with field programmable gate arrays, and a device capable of fast data acquisition. The micro-pixel detector element pulses had a short duration, the full width at half maximum of the pulse being 160 ns. Its gas gain was about 50 with an anode-cathode voltage of 560 V and a gas pressure of 0.5 MPa (0.45 MPa for He and 0.05 MPa for CF4). Signal pulse peaks of neutrons could be identified. The neutron detection system could easily distinguish neutron signals from other signals arising from electronic noise, gamma events, etc. The gas gain of the micro-pixel detector element did not change for 240 min in our irradiation test.
A retrospective study comprising analysis of CD4 Cell count among HIV infected patients in tertiary care hospital in western India

Introduction: HIV is one of the prevalent infectious disease and major threat to community. As the infection progresses, CD4 count hence, immunity decreases with time. CD4 count plays vital role in prognosis of HIV infection. Materials and Method: CD4 count reports of total of 109 HIV patients who registered and completed 6 months ART treatment during year 2016 were analyzed in this retrospective study. CD4 cell count was done using Flow Cytometry, FACS count (BD Diagnostic). Results: Baseline CD4 counts at diagnosis of infection for study group was 190.11 cell/cmm. Among them Male were having baseline value of 182.09 cells/cmm and female were having baseline value of 206.36 cells/cmm. After the initiation of ART there is consistent rise in CD4 count among study group patients. Conclusion: As the baseline CD4 count is low, patients in high risk group should be encouraged to visit ICTC centre for early detection of HIV. CD4 is mainstay among prognostic marker of HIV infection in India. Also steady intake of ART by HIV patients results in rise in CD4 count, increase in immunity and lowering of viral load. Keywords: HIV, ART, CD4
Fuzzy sentiment classification in social network facebook' statuses mining

Nowadays, posts expressing opinions in social networks are beneficial for businesses, sway public sentiments and emotions having higher social and political impact. In fact, opinions mining or sentiment classification is an important issue in social networks. Therefore, machine learning methods and natural language processing are very effective for opinion mining which are widely used in social media network. The main purpose of the paper is to demonstrate the feasibility of machine learning and sentiment analysis for studying Tunisian users' statuses. We aim to extract terms related to sentiment and behavior, especially during the “Tunisian Election”. While existing sentiment analysis methods focus only on the extraction of positive and negative opinions, in our work we aim to extract fuzzy opinions. That is why we propose to follow Fuzzy Support Vector Machine during our classification process. This later is compared with the basic Support Vector Machine referring to assessment measures such us accuracy, precision, recall, and F-measure.
Front end Electronics for SLHC Semiconductor Trackers in CMOS 90 nm and 130 nm Processes

We present the development of a front end amplifier and discriminator circuit implemented in two successive nodes of commercial CMOS process, namely 90 nm and 130 nm. The aim of this work is two-fold, firstly to examine new technology features such as increased transconductance and transit frequency $f_{t}$ resulting in higher speed at lower power consumption, and secondly to prototype a novel front end architecture developed to maintain high dynamic range and open loop gain in the presence of the degradation of intrinsic transistor gain and low supply voltage accompanying the scaling of CMOS processes. The circuits are intended to work with silicon strip detectors of moderate length. Although both versions are optimized for 5 pF input capacitance, the input stage of 130 nm front end can be biased with a current allowing for readout of detectors with capacitances of the order of 10 pF. Special attention has been given to the comparison of noise performance and matching of the channel gain and discriminator offsets. Although both versions show good basic analog performance in terms of speed and gain, an appreciable difference in the channel-to-channel matching and the noise figures is measured. The ENC performance of 130 nm version of the amplifier follows theoretical predictions confirming no excess noise for the devices used, whilst the noise performance of the 90 nm version is noticeably worse. Looking at the difference in noise performance between the two designs, the 130 nm process is better understood and is thus a more appropriate choice for the current upgrade project. As a consequence, the presented 130 nm design will form the core of the ABC130 chip for the ATLAS SCT upgrade.
A review of Harmony Search algorithm-based feature selection method for classification

In high dimensional datasets, feature selection plays a significant task for dimensionality reduction and classification. During feature selection process, only the most relevant features in the datasets will be selected. A good feature selection technique can reduce computation cost and increased classification performance. In this paper, we discuss the performance of feature selection with Harmony Search (HS) algorithm for classification in various applications. From the review, it can be concluded that feature selection with HS gives a good performance in many research areas as compared to other nature inspired metaheuristics algorithms such as Genetic Algorithm (GA) and Particle Swarm Optimization (PSO).
A conformal multi-frequency antenna array for safety-of-life satellite navigation

Satellite navigation is finding new applications in safety critical systems such as in aviation where it is proposed for approach and landing of aircraft. These new applications place strict requirements regarding position accuracy and system availability. In order to realize these requirements, it is essential to develop robust antenna designs. In this contribution, a multiband antenna array suitable for safety-of-life satellite navigation is presented. The array consists of 7 elements which are arranged on a half sphere. The single elements are resonant at the Galileo E5a/b and E1 frequency bands. The geometry of the array allows it to achieve stable gain and axial ratio performance over the whole upper hemisphere.
PP2 Prevents b-Adrenergic Stimulation of Cardiac Pacemaker Activity

One of the main strategies for cancer therapy is to use tyrosine kinase inhibitors for inhibiting tumor proliferation. Increasing evidence has demonstrated the potential risks of cardiac arrhythmias (such as prolonged QT interval) of these drugs. We report here that a widely used selective inhibitor of Src tyrosine kinases, 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2), can inhibit and prevent b-adrenergic stimulation of cardiac pacemaker activity. First, in dissected rat sinus node, PP2 inhibited and prevented the isoproterenol-induced increase of spontaneous beating rate. Second, in isolated rat sinus node myocytes, PP2 suppressed the hyperpolarization-activated “funny” current (traditionally called cardiac pacemaker current, If) by negatively shifting the activation curve and decelerating activation kinetics. Third, in isolated rat sinus node myocytes, PP2 decreased the Src kinase activity, the cell surface expression, and tyrosine phosphorylation of hyperpolarizationactivated, cyclic nucleotide–modulated channel 4 (HCN4) channel proteins. Finally, in human embryonic kidney 293 cells overexpressing recombinant human HCN4 channels, PP2 reversed the enhancement of HCN4 channels by isoproterenol and inhibited 573x, a cyclic adenosine momophosphate-insensitive human HCN4 mutant. These results demonstrated that inhibition of Src kinase activity in heart by PP2 decreased and prevented b-adrenergic stimulation of cardiac pacemaker activity. These effects are mediated, at least partially, by a cAMPindependent attenuation of channel activity and cell surface expression of HCN4, the main channel protein that controls the heart rate.
Back-contacted thin-film GaAs solar cells

In this work, we present a thin-film GaAs solar cell employing via contacts for forming a back-contacted solar cell to eliminate light blocking effects and enhance photon recycling at the same time. The fabrication procedure and the characterization of the fabricated devices are discussed in this paper. From our measurement, a conversion efficiency of 6.5%, open circuit voltage of 0.95 V, and a current density of 8.6mA/cm2 under one-sun illumination were obtained in a 5×5 mm cell.
Operation of a GEM-TPC with pixel readout

A prototype Time Projection Chamber with 26 cm drift length was operated with a short-spaced triple GEM stack in a setup triggering on cosmic muon tracks. A small part of the anode plane is read-out with a CMOS pixel-ASIC, the Timepix chip providing ultimate readout granularity. Clusters of charge depositions corresponding to single primary electrons are observed and analyzed to reconstruct charged particle tracks. A data set of several weeks of cosmic ray data is analyzed. The number of clusters per track length is well described by simulation. The obtained single point resolution approaches 50 µm at short drift distances and is well reproduced by a simple model of single electron diffusion.
A 14-bit 200-MS/s time-interleaved ADC calibrated with LMS-FIR and interpolation filter

A digital background calibration for time-interleaved ADC is presented. By using LMS-FIR and interpolation filter, mismatches of offset, gain, bandwidth, and sample-time error are calibrated. Adaptively controlled by correlation evaluation, the calibration is applicable for most input cases. A 14-bit 200-MS/s two-channel time-interleaved ADC is prototyped in a 0.18-µm CMOS process with core area of 15.2 mm2. The ADC achieves an SFDR of 88.9 dBc and an SNDR of 69.5 dBc after calibration, consuming 460 mW at 1.8 V.
Wafer Level Thin Film Encapsulation for MEMS

Because they have moving parts, or because they need to work in a specific atmosphere (vacuum, inert gas, etc.), micro-electromechanical systems (MEMS) are not compatible with standard integrated circuit (IC) packaging technologies. Specific packaging needs represent a great part of the final manufacturing cost of such devices. This article presents a solution to encapsulate RF MEMS devices in hermetically sealed cavities, using only standard IC manufacturing technologies at wafer level. A polymer sacrificial layer is deposited on the devices, and then covered with a dielectric cap. The cap is perforated with a standard lithography/etching process to enable the removing of the sacrificial layer by a dry process. The cap is finally vacuum sealed by a dielectric deposit. This thin film pre-packaging process enables MEMS protection and greatly reduces the cost of final packaging. A simplified device was designed and encapsulated under vacuum with the presented process. It allows to measure pressure evolution inside the cavity and by this way to check the hermeticity of the package
The Performance Evaluation of IEC Flicker Meters in Realistic Conditions

The light flicker effect is one of the most complex phenomena in the power quality field. It involves the voltage fluctuation shape, the lamp behavior and the eye-brain activity. As a first approach, the cause of light flicker was modeled in terms of voltage amplitude modulations, with a rectangular or sinusoidal shape. This is the main reason these modulated voltage waveforms have been adopted to evaluate the performance of IEC light flicker meter. Unfortunately, in realistic conditions the observed voltage fluctuations have usually more complex shapes, so it might happen that two IEC flicker meters give different measurement results for the same voltage input, depending on the different implementation. In this paper we are mostly concerned with the synthesis of an automatic test system for the evaluation of the IEC light flicker meter performance and the measurement of the short-time severity index (Pst) with a standard IEC flicker meter, when a wide set of complex modulating shapes are applied to the voltage
State Estimation Based External Network Solution for on-line Security Analysis

A major difficulty in on-line security analysis of power systems is the representation of the external but interconnected network from which very little or no real time data are available. One method used for the determination of the external system state is to extrapolate or assume real time data for a large external network representation, which is then solved by a power flow in such a way that the mismatches at the boundary between this external system solution and the state estimated internal network is minimized. This paper presents a method that extends the state estimation techniques, instead of using the power flow for the external network solution. The results indicate improved solution flexibility, sensitivity, error detection and location abilities, and significant reduction in boundary errors.